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Sample records for rerio oryzias latipes

  1. Identifcation of Novel Retroid Agents in Danio rerio, Oryzias latipes, Gasterosteus aculeatus and Tetraodon nigroviridis

    Holly A. Basta

    2007-01-01

    Full Text Available Retroid agents are genomes that encode a reverse transcriptase (RT and replicate or transpose by way of an RNA intermediate. The Genome Parsing Suite (GPS is software created to identify and characterize Retroid agents in any genome database (McClure et al. 2005. The detailed analysis of all Retroid agents found by the GPS in Danio rerio (zebrafsh, Oryzias latipes (medaka, Gasterosteus aculeatus (stickleback and Tetraodon nigroviridis (spotted green pufferfish reveals extensive Retroid agent diversity in the compact genomes of all four fish. Novel Retroid agents were identified by the GPS software: the telomerase reverse transcriptase (TERT in O. latipes, G. aculeatus and T. nigroviridis and a potential TERT in D. rerio, a retrotransposon in D. rerio, and multiple lineages of endogenous retroviruses (ERVs in D. rerio, O. latipes and G. aculeatus.

  2. Benzo(a)pyrene-induced cytochrome p4501A expression of four freshwater fishes (Oryzias latipes, Danio rerio, Cyprinus carpio, and Zacco platypus).

    Lee, Jin Wuk; Yoon, Hong-Gil; Lee, Sung Kyu

    2015-05-01

    Oryzias latipes, Danio rerio, Cyprinus carpio, and Zacco platypus are useful indicator species for CYP1A biomarker studies; however, comparative studies have not been performed. To compare susceptibility, dose- and time-dependent CYP1A induction at the mRNA and protein levels in response to benzo(a)pyrene (BaP) exposure was analyzed. At the mRNA level, a statistically significant difference was found among the four species; however, such was not observed at the protein level. C. carpio showed the highest CYP1A induction level and the steepest slope in the dose-response curve. To assess susceptibility, the difference in CYP1A mRNA induction among species must be considered, and C. carpio was the most sensitive species of the four evaluated in terms of CYP1A expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. RELATIONSHIP BETWEEN ETHINYLESTRADIOL-MEDIATED CHANGES IN ENDOCRINE FUNCTION AND REPRODUCTION IMPAIRMENT IN JAPANESE MEDAKA (ORYZIAS LATIPES)

    Many biochemical endpoints currently are used to describe endocrine function in fish; however, the sensitivity of these parameters as biomarkers of impaired reproduction or sexual development is not well understood. In the present study, adult Japanese medaka (Oryzias latipes) we...

  4. USE OF THE JAPANESE MEDAKA (ORYZIAS LATIPES) AND GUPPY (POECILIA RETICULATA) IN CARCINOGENESIS TESTING UNDER NATIONAL TOXICOLOGY PROGRAM PROTOCOLS

    that are economical, sensitive, and scientifically acceptable. Among small fish models, the Japanese medaka (Oryzias latipes) is preeminent for investigating effects of carcinogenic and/or toxic waterborne hazards to humans. The guppy (Poecilia reticulata), although less widely u...

  5. Specification of primordial germ cells in medaka (Oryzias latipes

    Raz Erez

    2007-01-01

    Full Text Available Abstract Background Primordial germ cells (PGCs give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes. Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of

  6. Past seawater experience enhances seawater adaptability in medaka, Oryzias latipes.

    Miyanishi, Hiroshi; Inokuchi, Mayu; Nobata, Shigenori; Kaneko, Toyoji

    2016-01-01

    During the course of evolution, fishes have acquired adaptability to various salinity environments, and acquirement of seawater (SW) adaptability has played important roles in fish evolution and diversity. However, little is known about how saline environments influence the acquirement of SW adaptability. The Japanese medaka Oryzias latipes is a euryhaline species that usually inhabits freshwater (FW), but is also adaptable to full-strength SW when transferred through diluted SW. In the present study, we examined how past SW experience affects hyposmoregulatory ability in Japanese medaka. For the preparation of SW-experienced fish, FW medaka were acclimated to SW after pre-acclimation to 1/2 SW, and the SW-acclimated fish were transferred back to FW. The SW-experienced fish and control FW fish (SW-inexperienced fish) were transferred directly to SW. Whereas control FW fish did not survive direct transfer to SW, 1/4 of SW-experienced fish adapted successfully to SW. Although there were no significant differences in blood osmolality and plasma Na(+) and Cl(-) concentrations between SW-experienced and control FW medaka in FW, increments in these parameters following SW transfer were lower in SW-experienced fish than in control FW fish. The gene expression of SW-type Na(+), K(+)-ATPase (NKA) in the gills of SW-experienced medaka increased more quickly after direct SW transfer compared with the expression in control FW fish. Prior to SW transfer, the density of NKA-immunoreactive ionocytes in the gills was higher in SW-experienced fish than in control FW fish. Ionocytes expressing CFTR Cl(-) channel at the apical membrane and those forming multicellular complexes, both of which were characteristic of SW-type ionocytes, were also increased in SW-experienced fish. These results indicate that past SW experience enhances the capacity of Na(+) and Cl(-) secretion in ionocytes and thus hypoosmoregulatory ability of Japanese medaka, suggesting the presence of epigenetic

  7. Assessing developmental toxicity of caffeine and sweeteners in medaka (Oryzias latipes)

    Lee, Wenjau; Wang, Yun-Chi

    2015-01-01

    The use of artificial sweeteners (ASWs) has increased and become more widespread, and consequently ASWs have appeared in aquatic environments around the world. However, their safety to the health of humans and wildlife remains inconclusive. In this study, using medaka embryos (Oryzias latipes), we investigated developmental toxicity of aspartame (ASP) and saccharin (SAC). Since ASWs are often consumed with caffeine (CAF) and CAF with sucrose (SUC), we tested biological activities of these fou...

  8. Adverse effects of tributyltin on reproduction of Japanese medaka, Oryzias latipes

    NAKAYAMA, Kei; OSHIMA, Yuji

    2008-01-01

    Tributyltin (TBT) is a typical endocrine disruptor that can induce imposex in mollusks and interfere with the reproduction in bivalves and fish. Our group has been studied the toxic effects of TBT using Japanese medaka (Oryzias latipes) as a model organism, and evaluated the effects on reproduction and behavior of medaka exposed to TBT. A series of our studies has demonstrated that TBT suppresses mating behavior in male and depresses fertility. We also observed that TBT exposure causes abnorm...

  9. An Adaptive Modeling Technique for Instream Fish Habitat Preference of Japanese Medaka (Oryzias Latipes)

    Fukuda, Shinji; Hiramatsu, Kazuaki; Mori, Makito; Shikasyo, Shiomi

    2005-01-01

    It is widely known that habitat selections of riverine fish differ within and between rivers. In our past study, the preference intensity of Japanese Medaka (Oryzias latipes) to three environmental factors of water depth, current velocity and cover ratio was quantified on laboratory open-channel experiments for developing a general habitat preference model. A simplified fuzzy reasoning method was introduced in consideration of essential vagueness of fish behaviors. The fuzzy preference inten...

  10. Bioaccumulation of 14C-hexachlorobenzene in eggs and fry of Japanese medaka (Oryzias latipes)

    Huang, Y.; Biddinger, G.R.; Gloss, S.P.

    1986-01-01

    Hexachlorobenzene (HCB) is a widespread pollutant that is persistent once it enters the ecosphere. It bioaccumulates in both terrestrial and aquatic animals and is not readily metabolized. Although HCB bioaccumulation in fresh water fish has been reported, few data are available on bioaccumulation of this or other chemicals during early developmental stages of fish. The authors used the Japanese medaka (Oryzias latipes) to examine the rates of HCB bioaccumulation during early life stages subjected to both short term (24 h) and long term (14 day) aqueous exposure. The relatively rapid development and ease of laboratory maintenance made the medaka an ideal organism for this purpose

  11. Developmental regulation of neuroligin genes in Japanese rice fish (oryzias latipes) embryogenesis maintains the rhythym during ethanol-in

    Although prenatal alcohol exposure is the potential cause of fetal alcohol spectrum disorder (FASD) in humans, the molecular mechanism(s) of FASD is yet unknown. We have used Japanese rice fish (Oryzias latipes) embryogenesis as an animal model of FASD and reported that this model has effectively ge...

  12. ALTERED GENE EXPRESSION AND DEVELOPMENT OF POTENTIAL BIOMARKERS IN MEDAKA (ORYZIAS LATIPES) BRAIN, LIVER AND TESTIS FOLLOWING EXPOSURE TO FIBRATE PHARMACEUTICALS

    To help address the consequences of increasing levels of environmental contaminants and to identify potentially novel markers of toxicity, we examined gene expression profiles from medaka (Oryzias latipes) exposed to a prototypical fibrate pharmaceutical. Changes in gene express...

  13. Alteration of General Behavior of Male Medaka,oryzias latipes,Exposed to Tributyltin and /or Polychlorinated Biphenyls

    Nakayama, Kei; Oshima, Yuji; Hiramatsu, Kazuaki; Honjo, Tsuneo

    2004-01-01

    We examined the general behavior of male Japanese medaka, Oryzias latipes, after exposed to tributyltin (TBT), polychlorinated biphenyls (PCBs), or a mixture of these chamicals at a concentration of 1μg/g body weight daily for 3 weeks. We analyzed swimming velocity as an indicator of acute toxicity and counted the frequencies of straight swimming and swimming in circles. We also calclated the entropy of the positions of the fish within the experimental chamber. Neither TBT nor PCBs nor their ...

  14. Differential maturation of rhythmic clock gene expression during early development in medaka (Oryzias latipes).

    Cuesta, Ines H; Lahiri, Kajori; Lopez-Olmeda, Jose Fernando; Loosli, Felix; Foulkes, Nicholas S; Vallone, Daniela

    2014-05-01

    One key challenge for the field of chronobiology is to identify how circadian clock function emerges during early embryonic development. Teleosts such as the zebrafish are ideal models for studying circadian clock ontogeny since the entire process of development occurs ex utero in an optically transparent chorion. Medaka (Oryzias latipes) represents another powerful fish model for exploring early clock function with, like the zebrafish, many tools available for detailed genetic analysis. However, to date there have been no reports documenting circadian clock gene expression during medaka development. Here we have characterized the expression of key clock genes in various developmental stages and in adult tissues of medaka. As previously reported for other fish, light dark cycles are required for the emergence of clock gene expression rhythms in this species. While rhythmic expression of per and cry genes is detected very early during development and seems to be light driven, rhythmic clock and bmal expression appears much later around hatching time. Furthermore, the maturation of clock function seems to correlate with the appearance of rhythmic expression of these positive elements of the clock feedback loop. By accelerating development through elevated temperatures or by artificially removing the chorion, we show an earlier onset of rhythmicity in clock and bmal expression. Thus, differential maturation of key elements of the medaka clock mechanism depends on the developmental stage and the presence of the chorion.

  15. Chromosomal studies on radiation-induced gynogenesis and diploid gynogenesis in the fish Oryzias latipes

    Ijiri, Kenichi

    1983-01-01

    When sperm of the fish Oryzias latipes exposed to radiation fertilize normal eggs, the 'Hertwig effect' occurs, namely a high mortality of embryos at low doses but a better survival at high doses. This phenomenon induced by ultraviolet light (UV) or gamma-rays was previously studied quantitatively using the survival frequencies of embryos at various stages during their development. From the genetic analysis of both UV and gamma-ray effects, using the wild-type sperm of this species and then checking the appearance of melanophores on the yolk sacs of embryos, it was suggested that sperm chromosomes do not participate in embryonic development at high doses. The number of chromosomes in cells of the embryos which survive till stage 26 were counted, finding haploid embryos in the dose region of the Hertwig phenomenon. The analysis of chromosome number was mostly in agreement with the genetic studies, but there existed a few cases in which these two methods of analysis did show the opposite results. From these data, the validity of the genetic studies based on the appearance of melanophores on the yolk sac is discussed. Attempts to produce diploid gynogenesis through the cold temperature treatment are also reported. (author)

  16. Chronic fluoxetine treatment induces anxiolytic responses and altered social behaviors in medaka, Oryzias latipes.

    Ansai, Satoshi; Hosokawa, Hiroshi; Maegawa, Shingo; Kinoshita, Masato

    2016-04-15

    Medaka (Oryzias latipes) is a small freshwater teleost that is an emerging model system for neurobehavioral research and toxicological testing. The selective serotonin reuptake inhibitor class of antidepressants such as fluoxetine is one of the widely prescribed drugs, but little is known about the effects of these drugs on medaka behaviors. To assess the behavioral effects of fluoxetine, we chronically administrated fluoxetine to medaka adult fish and analyzed the anxiety-related and social behaviors using five behavioral paradigms (diving, open-field, light-dark transition, mirror-biting, and social interaction) with an automated behavioral testing system. Fish chronically treated with fluoxetine exhibited anxiolytic responses such as an overall increased time spent in the top area in the diving test and an increased time spent in center area in the open-field test. Analysis of socially evoked behavior showed that chronic fluoxetine administration decreased the number of mirror biting times in the mirror-biting test and increased latency to first contact in the social interaction test. Additionally, chronic fluoxetine administration reduced the horizontal locomotor activity in the open-field test but not the vertical activity in the diving test. These investigations are mostly consistent with previous reports in the other teleost species and rodent models. These results indicate that behavioral assessment in medaka adult fish will become useful for screening of effects of pharmaceutical and toxicological compounds in animal behaviors. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes embryos

    Wu Dong

    2016-08-01

    Full Text Available This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes embryos were exposed to 0.001–10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha, and β-HgS (Zuotai from stage 10 (6–7 hpf to 10 days post fertilization (dpf. Of the forms of mercury in this study, the organic form (MeHg proved the most toxic followed by inorganic mercury (HgCl2, both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM, HgCl2 (1 µM, α-HgS (10 µM, or β-HgS (10 µM to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT and heme oxygenase-1 (Ho-1, while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

  18. Effects of methyl testosterone exposure on sexual differentiation in medaka, Oryzias latipes

    Papoulias, D.M.; Noltie, Douglas B.; Tillitt, D.E.

    2000-01-01

    Studies were conducted to characterize effects of a known androgen on sexual differentiation and development of medaka, Oryzias latipes (d-rR strain), at two life stages. Embryos were injected with graded doses of methyl testosterone (MT) prior to epiboly. The occurrence of sex-reversal, and the gonadosomatic index (GSI) were evaluated in adults. Primary germ cells were counted and gonad volumes calculated for larvae to determine if sex-reversal could be detected at an early life stage. Sex-reversal of genetic females to phenotypic males was observed at both life stages. The GSI for phenotypic females was greater than for phenotypic males, while the GSI in XX males was similar to XY males. MT appeared to reduce the GSI of XX females exposed to MT but not sex-reversed. Our results indicate that embryonic exposure to androgens influences sexual development in medaka. Utilizing the d-rR strain of medaka allows detection of an effect as early as 2 weeks after chemical exposure making this a useful tool to screen chemicals for effects on sexual differentiation. Copyright (C) 2000.

  19. A genetic screen for mutations affecting embryonic development in medaka fish (Oryzias latipes).

    Loosli, F; Köster, R W; Carl, M; Kühnlein, R; Henrich, T; Mücke, M; Krone, A; Wittbrodt, J

    2000-10-01

    In a pilot screen, we assayed the efficiency of ethylnitrosourea (ENU) as a chemical mutagen to induce mutations that lead to early embryonic and larval lethal phenotypes in the Japanese medaka fish, Oryzias latipes. ENU acts as a very efficient mutagen inducing mutations at high rates in germ cells. Three repeated treatments of male fish in 3 mM ENU for 1 h results in locus specific mutation rates of 1.1-1.95 x10(-3). Mutagenized males were outcrossed to wild type females and the F1 offspring was used to establish F2 families. F2 siblings were intercrossed and the F3 progeny was scored 24, 48 and 72 h after fertilization for morphological alterations affecting eye development. The presented mutant phenotypes were identified using morphological criteria and occur during early developmental stages of medaka. They are stably inherited in a Mendelian fashion. The high efficiency of ENU to induce mutations in this pilot screen indicates that chemical mutagenesis and screening for morphologically visible phenotypes in medaka fish allows the genetic analysis of specific aspects of vertebrate development complementing the screens performed in other vertebrate model systems.

  20. Evaluation of 2,4-dichlorophenol exposure of Japanese medaka, Oryzias latipes, using a metabolomics approach.

    Kokushi, Emiko; Shintoyo, Aoi; Koyama, Jiro; Uno, Seiichi

    2017-12-01

    In this study, the metabolic effects of waterborne exposure of medaka (Oryzias latipes) to nominal concentrations of 20 (L group) and 2000 μg/L (H group) 2,4-dichlorophenol (DCP) were examined using a gas chromatography/mass spectroscopy (GC/MS) metabolomics approach. A principal component analysis (PCA) separated the L, H, and control groups along PC1 to explain the toxic effects of DCP at 24 h of exposure. Furthermore, the L and H groups were separated along PC1 at 96 h on the PCA score plots. These results suggest that the effects of DCP depended on exposure concentration and time. Changes in tricarboxylic cycle metabolites suggested that fish exposed to 2,4-DCP require more energy to metabolize and eliminate DCP, particularly at 96 h of exposure. A time-dependent response in the fish exposed to DCP was observed in the GC/MS data, suggesting that the higher DCP concentration had greater effects at 24 h than those observed in response to the lower concentration. In addition, several essential amino acids (arginine, histidine, lysine, isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, and valine) decreased after DCP exposure in the H group, and starvation condition and high concentration exposure of DCP could consume excess energy from amino acids.

  1. The notochord curvature in medaka (Oryzias latipes) embryos as a response to ultraviolet A irradiation.

    Sayed, Alaa El-Din Hamid; Mitani, Hiroshi

    2016-11-01

    In the present work, the destructive effects of ultraviolet A (UVA; 366nm) irradiation on the developmental stages of Japanese medaka (Oryzias latipes) are revealed in terms of hatching success, mortality rate, and morphological malformations (yolk sac edema, body curvature, fin blistering, and dwarfism). Fertilized eggs in stage 4 were exposed to 15, 30, and 60min/day UVA for 3days in replicates. Fish were staged and aged following the stages established by Iwamatsu [1]. We observed and recorded the hatching time and deformed and dead embryos continuously. The hatching time was prolonged and the deformed and dead embryos numbers were increased by UVA dose increase. At stage 40, samples from each group were fixed to investigate their morphology and histopathology. Some morphological malformations were recorded after UVA exposure in both strains. Histopathological changes were represented as different shapes of curvature in notochord with collapse. The degree of collapsation was depended on the dose and time of UVA exposure. Our findings show that exposure to UVA irradiation caused less vertebral column curvature in medaka fry. Moreover, p53-deficient embryos were more tolerant than those of wild-type (Hd-rR) Japanese medaka. This study indicated the dangerous effects of the UVA on medaka. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Habituation of medaka (Oryzias latipes) demonstrated by open-field testing.

    Matsunaga, Wataru; Watanabe, Eiji

    2010-10-01

    Habituation to novel environments is frequently studied to analyze cognitive phenotypes in animals, and an open-field test is generally conducted to investigate the changes that occur in animals during habituation. The test has not been used in behavioral studies of medaka (Oryzias latipes), which is recently being used in behavioral research. Therefore, we examined the open-field behavior of medaka on the basis of temporal changes in 2 conventional indexes of locomotion and position. The findings of our study clearly showed that medaka changed its behavior through multiple temporal phases as it became more familiar with new surroundings; this finding is consistent with those of other ethological studies in animals. During repeated open-field testing on 2 consecutive days, we observed that horizontal locomotion on the second day was less than that on the first day, which suggested that habituation is retained in fish for days. This temporal habituation was critically affected by water factors or visual cues of the tank, thereby suggesting that fish have spatial memory of their surroundings. Thus, the data from this study will afford useful fundamental information for behavioral phenotyping of medaka and for elucidating cognitive phenotypes in animals. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. On the manganese content of the egg of Oryzias latipes and its change during the early development

    Hori, R.; Iwasaki, S.I.

    1976-01-01

    The content of manganese of the egg of Oryzias latipes was determined by atomic absorption spectrophotometry and activation analysis. The amount of manganese in the unfertilized egg was 0.51 mμg and increased remarkably in one hour after fertilization. Although the increasing rate became gradually lower in further stages, the content of manganese amounted to 2.61 mμg in the embryo after gastrulation. Tracer-experiments showed that the egg accumulated manganese positively from the surrounding medium during the short time after fertilization. (author)

  4. Effects of gamma-rays on the taste buds of embryos and adults of the fish Oryzias latipes

    Ghoneum, M.M.H.; Ijiri, K.; Egami, N.; Hamed, M.S.; Gabr, O.M.

    1983-01-01

    The present study was performed in order to evaluate the state of activity of the taste bud cells of the fish Oryzias latipes. Two types of taste bud cells, namely pale cells and dark cells were distinguished and scored separately. From the irradiation experiment on adult fish, it was found that pale cells were more radiosensitive than are dark cells. At 10 days after irradiation with 1000 R, repopulation of the pale cells was observed and their number returned almost to the control value. In the experiments using various stages of embryos, the formation of the taste bud cells was highly radiosensitive at their early embryonic stages. (author)

  5. GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES) EXPOSED TO O,P'-DDT IN WATER OR THROUGH MATERNAL TRANSFER

    Various isomers and metabolites of DDT disrupt endocrine systems and gonadal development in fish andxwildlife and o,p'-DDT has been shown to be a relatively potent estrogen agonist. In this study, we exposed Japanese medaka (Oryzias latipes) to o,p'-DDT using two exposure protoco...

  6. Fish short-term reproduction assay with atrazine and the Japanese medaka (Oryzias latipes).

    Hosmer, Alan J; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Brain, Richard A

    2017-09-01

    Breeding groups of Japanese medaka (Oryzias latipes) were exposed to atrazine at measured concentrations of 0.6, 5.5, and 53 μg/L for 35 d. Evaluated endpoints included survival, fecundity, fertility, growth (weight and length), behavior, secondary sex characteristics (anal fin papillae), gonad histopathology, and hepatic vitellogenin. No statistically significant effects of atrazine exposure on survival and growth of medaka were noted during the test, and mean survival was ≥97.5% in all treatment groups on day 35. No significant effects of atrazine exposure on reproduction were observed. The number of mean cumulative eggs produced in the negative control and the 0.6, 5.5, and 53 μg/L treatment groups was 7158, 6691, 6883, and 6856, respectively. The mean number of eggs per female reproductive day was 40.9, 38.2, 40.2, and 39.2, respectively. There were also no dose-dependent effects on mean anal fin papillae counts among male fish or expression of vtg-II in males or females. In addition, atrazine exposure was not related to the developmental stage of test fish, with testes stages ranging from 2 to 3 in all groups and ovaries ranging from stage 2 to 2.5. Overall, exposure to atrazine up to 53 µg/L for 35 d did not result in significant, treatment-related effects on measured endpoints related to survival, growth, or reproduction in Japanese medaka. Environ Toxicol Chem 2017;36:2327-2334. © 2017 SETAC. © 2017 SETAC.

  7. Quantifiable biomarkers of normal aging in the Japanese medaka fish (Oryzias latipes.

    Lingling Ding

    2010-10-01

    Full Text Available Small laboratory fish share many anatomical and histological characteristics with other vertebrates, yet can be maintained in large numbers at low cost for lifetime studies. Here we characterize biomarkers associated with normal aging in the Japanese medaka (Oryzias latipes, a species that has been widely used in toxicology studies and has potential utility as a model organism for experimental aging research.The median lifespan of medaka was approximately 22 months under laboratory conditions. We performed quantitative histological analysis of tissues from age-grouped individuals representing young adults (6 months old, mature adults (16 months old, and adults that had survived beyond the median lifespan (24 months. Livers of 24-month old individuals showed extensive morphologic changes, including spongiosis hepatis, steatosis, ballooning degeneration, inflammation, and nuclear pyknosis. There were also phagolysosomes, vacuoles, and residual bodies in parenchymal cells and congestion of sinusoidal vessels. Livers of aged individuals were characterized by increases in lipofuscin deposits and in the number of TUNEL-positive apoptotic cells. Some of these degenerative characteristics were seen, to a lesser extent, in the livers of 16-month old individuals, but not in 6-month old individuals. The basal layer of the dermis showed an age-dependent decline in the number of dividing cells and an increase in senescence-associated β-galactosidase. The hearts of aged individuals were characterized by fibrosis and lipofuscin deposition. There was also a loss of pigmented cells from the retinal epithelium. By contrast, age-associated changes were not apparent in skeletal muscle, the ocular lens, or the brain.The results provide a set of markers that can be used to trace the process of normal tissue aging in medaka and to evaluate the effect of environmental stressors.

  8. Effects of triphenyltin on reproduction in Japanese medaka (Oryzias latipes) across two generations.

    Horie, Yoshifumi; Watanabe, Haruna; Takanobu, Hitomi; Shigemoto, Yoshiko; Yamagishi, Takahiro; Iguchi, Taisen; Tatarazako, Norihisa

    2017-11-01

    Triphenyltin (TPT) is an organotin compound used in marine anti-fouling coatings to prevent the attachment and growth of marine organisms, and it has negative effects on aquatic organisms. TPT is still detected at low concentrations, although its use has been prohibited at least in the European Community and is restricted in Japan as well. Studies using Japanese medaka (Oryzias latipes) indicate that TPT has the potential to inhibit reproduction. Although TPT is detected in many aquatic ecosystems, the multi-generational impact of TPT remains unknown. We investigated the two-generational effects of TPT on Japanese medaka and examined the relationships of several such effects between the F0 and F1 generations. Suppression of fecundity was observed in both generations, and fertility and growth were inhibited in the F1 generation. Moreover, delayed hatching and lower hatchability were observed in F1 embryos. Importantly, the value of the lowest observed effect concentration (LOEC) for these influences in F1 was lower than that in F0: that is, the LOEC values of fecundity and mortality were 3.2μg/L in the F0 generation and 1.0μg/L in the F1 generation. Fertility was not affected by TPT in F0, whereas it was significantly suppressed in the 1.0μg/L-exposure group of the F1 generation. Our results provide the first evidence of the effects of TPT on reproduction in a teleost fish across two generations, highlighting the concern that TPT could affect reproduction and mortality at decreasing concentrations in temporally overlapping generations. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Toxicity implications for early life stage Japanese medaka (Oryzias latipes) exposed to oxyfluorfen.

    Powe, Doris K; Dasmahapatra, Asok K; Russell, Joseph L; Tchounwou, Paul B

    2018-05-01

    We investigated the potential toxic effects of Oxyfluorfen (OXY), an herbicide used in agriculture, on the embryo-larval development of Japanese medaka fish (Oryzias latipes). Embryos (1-day postfertilization) and larvae (2-day posthatch) were exposed to OXY (0.5-8 mg/L) for 96 h and evaluated for mortality and hatching on embryos, and the mortality and growth on larvae during depuration. It was observed that the embryo-mortality was inconsistently altered by OXY; only the 2 mg/L group showed significant reduction on embryo survivability. However, larval-mortality was concentration-dependent and OXY exposure induced scoliosis-like phenotypic features in the surviving larvae; the calculated LC 50 was 5.238 mg/L. Our data further indicated that larval skeleton, both axial and appendicular, was the potential target site of OXY. Skeletal growth in larvae exposed to 2 mg/L was inhibited significantly until 1 week of depuration with regard to the linear lengths of neurocranium, Meckel's cartilage, caudal vertebrae (first 10) in the axial skeletons, and pectoral fin and urostyle in the appendicular skeletons. Moreover, the total protein content remained unaltered by OXY after 96 h exposure; while the RNA concentration was reduced significantly in larvae exposed to 2 mg/L. Expression analysis of several genes by quantitative real-time RT-PCR (RT-qPCR) showed significant upregulation of zic5, a zinc-finger type transcription regulator, at the transcription level. This study indicated that the scoliosis induced by OXY in Japanese medaka larvae was the result of stunted skeletal growth, probably because of deregulation of zinc-finger type transcription regulators, at the genomic level. © 2018 Wiley Periodicals, Inc.

  10. Aquatic toxicity of cartap and cypermethrin to different life stages of Daphnia magna and Oryzias latipes.

    Kim, Younghee; Jung, Jinyong; Oh, Sorin; Choi, Kyungho

    2008-01-01

    Cartap and cypermethrin, which are among the most widely used pesticides in many countries, are considered safe because of their low mammalian toxicity and their low persistence in the environment. However, recent findings of endocrine-disrupting effects and developmental neurotoxicity have raised concerns about the potential ecological impacts of these pesticides. We evaluated the aquatic toxicity of cartap [S,S'-(2-dimethylaminotrimethylene) bis(thiocarbamate), unspecified hydrochloride] and cypermethrin [(RS)-alpha-cyano-3-phenoxybenzyl-(1RS,3RS,1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate], both individually and combined, on different life stages of the freshwater cladoceran Daphnia magna and a freshwater teleost, Japanese medaka (Oryzias latipes). The 96-hr Daphnia median effective concentrations (EC50s) for cartap and cypermethrin were 91.0 microg/L and 0.00061 microg/L, respectively. Rapid recovery of Daphnia was observed after short-term pulsed exposure to cartap and cypermethrin; there were no adverse effects on reproduction or survival 20 d after a 24 hr exposure to cartap up to 1240 microg/L and cypermethrin up to 1.9 microg/L. Chronic continuous exposure (for 21 d) of 7-d-old Daphnia to cypermethrin significantly reduced the intrinsic population growth rate in a concentration-dependent manner. However, because the intrinsic population growth rates were all above zero, populations did not decrease even at the highest experimental concentration of 200 ng/L. Exposure of Daphnia neonates (cartap or 40 microg/L of cypermethrin. The mixture of both compounds showed no synergistic toxicity. The extremely high acute-to-chronic ratio suggests that the standard acute lethal toxicity assessment might not reflect the true environmental hazards of these frequently used pesticides. Ecological hazard assessments of long-term low dose or pulsed exposures to cartap and cypermethrin may reveal more realistic consequences of these compounds in

  11. Change in the radiation responses of oogonia in the embryos and fry of the fish Oryzias latipes

    Hamaguchi, S.

    1976-01-01

    Embryos of the fish Oryzias latipes were irradiated with 1000 R of X-rays 1 day before hatching, and the post-irradiation change in the female germ-cell population was observed. Scarcely any reduction in the number of oogonia was observed, but their proliferation was inhibited. Repopulation occurred between 12 and 20 days after hatching. These responses were quite different from those of germ cells in the irradiated fry. Embryos and/or fry were also exposed to 1000 R of X-rays 1 day before hatching and 0, 1, 2, and 3 days after hatching. A comparison of their responses suggested that the change in the radiation responses of oogonia is correlated with the initiation of meiosis. (author)

  12. Effects of gamma-rays on morphology of the thymus of the adult fish of Oryzias latipes

    Ghoneum, M.M.H.; Ijiri, Ken-ichi; Egami, Nobuo

    1982-01-01

    The effects of gamma-rays on the thymus in the adult fish of Oryzias latipes were studied. Fish were subjected to a single whole-body irradiation of the dose ranging from 0 to 8 kR. Through the histological sections, the quantitative treatment was performed on the changes in thymus volume and mitotic activity of thymocytes after irradiation. The thymus in the irradiated fish exhibited a sudden drop in its volume on day 1-3 post-irradiation, subsequently followed by its regeneration. The change in mitotic index of thymocytes, especially in the regeneration phase, showed a dose-dependent behavior (same level as the control for 10 and 25 R; and overshoot for 100 and 200 R; a gradual recovery for 1 and 2 kR; no mitosis for 4 and 8 kR). (author)

  13. The utility of the guppy (Poecilia reticulata) and medaka (Oryzias latipes) in evaluation of chemicals for carcinogenicity.

    Kissling, Grace E; Bernheim, Naomi J; Hawkins, William E; Wolfe, Marilyn J; Jokinen, Micheal P; Smith, Cynthia S; Herbert, Ronald A; Boorman, Gary A

    2006-07-01

    There has been considerable interest in the use of small fish models for detecting potential environmental carcinogens. In this study, both guppies (Poecilia reticulata) and medaka (Oryzias latipes) were exposed in the aquaria water to three known rodent carcinogens for up to 16 months. Nitromethane, which caused mammary gland tumors by inhalation exposure in female rats, harderian gland and lung tumors in male and female mice, and liver tumors in female mice by inhalation, failed to increase tumors in either guppies or medaka. Propanediol, which when given in the feed was a multisite carcinogen in both sexes of rats and mice, caused increased liver tumors in male guppies and male medaka. There was reduced survival in female guppies and no increased tumors in female medaka. 1,2,3-Trichloropropane, which when administered by oral gavage was a multisite carcinogen in both sexes of rats and mice, caused an increased incidence of tumors in the liver of both male and female guppies and medaka and in the gallbladder of male and female medaka. The results of this study demonstrate that for these three chemicals, under these specific exposure conditions, the fish appear less sensitive and have a narrower spectrum of tissues affected than rodents. These results suggest that fish models are of limited utility in screening unknown chemicals for potential carcinogenicity.

  14. Evaluation of potential mechanisms of atrazine-induced reproductive impairment in fathead minnow (Pimephales promelas) and Japanese medaka (Oryzias latipes)

    Richter, Cathy; Papoulias, Diana M.; Whyte, Jeffrey J.; Tillitt, Donald E.

    2016-01-01

    Atrazine has been implicated in reproductive dysfunction of exposed organisms, and previous studies documented decreased egg production in Japanese medaka (Oryzias latipes) and fathead minnows (Pimephales promelas) during 30-d to 38-d exposures to 0.5 µg/L, 5 µg/L, and 50 µg/L atrazine. The authors evaluated possible mechanisms underlying the reduction in egg production. Gene expression in steroidogenesis pathways and the hypothalamus–pituitary–gonad axis of male and female fish was measured. Atrazine did not significantly induce gonad aromatase (cyp19a1a) expression. An atrazine-induced shift in the number of females in an active reproductive state was observed. Expression of the egg maturation genes vitellogenin 1 (vtg1) and zona pellucida glycoprotein 3.1 (zp3.1) in medaka females was correlated and had a bimodal distribution. In both species, females with low vtg1 or zp3.1 expression also had low expression of steroidogenesis genes in the gonad, estrogen receptor in the liver, and gonadotropins in the brain. In the medaka, the number of females per tank that had high expression of zp3.1 was significantly correlated with egg production per tank. The number of medaka females with low expression of zp3.1 increased significantly with atrazine exposure. Thus, the decline in egg production observed in response to atrazine exposure may be the result of a coordinated downregulation of genes required for reproduction in a subset of females.

  15. Effects of tributyltin on early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes).

    Horie, Yoshifumi; Yamagishi, Takahiro; Shintaku, Yoko; Iguchi, Taisen; Tatarazako, Norihisa

    2018-07-01

    Tributyltin, an organotin compound, was used worldwide as an antifouling agent in aquatic environments and there has been much concern about the toxicological and ecotoxicological properties of organotin compounds. Even though it has been prohibited worldwide, tributyltin is still detected at low concentrations in aquatic environments. Here we investigated the effects of tributyltin on the early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes). In adults, exposure to tributyltin at 3.82 μg/L suppressed fecundity and fertility and increased mortality. At 10.48 μg/L all medaka died by the sixth day of exposure. Exposure to tributyltin during early life-stages induced no significant differences in mortality or embryonic development, but growth was suppressed in groups exposed to 0.13 and 0.68 μg/L. Furthermore, there was no abnormal gonadal development in Japanese medaka exposed to tributyltin. These results provide evidence of the negative effects of tributyltin on reproduction in a teleost fish. Tributyltin did not affect gonadal sex differentiation in Japanese medaka, but fecundity and fertility were suppressed, although it is not clear whether this suppression resulted from the endocrine-disrupting action of tributyltin or its toxicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Radioecological studies of 137Cs in limnological ecosystems. Biochemical states of 137Cs accumulated in killifish (Medaka, Oryzias latipes) meat

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki; Izumo, Yoshiro; Nakamura, Fumio.

    1997-01-01

    Biochemical states of 137 Cs accumulated in killifish's (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of 137 Cs radioactivity in the killifish's raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish's control raw meat mixed with 137 Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to 137 CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD 280nm in the samples were different from those of each radioactive peak. It was so suggested that 137 Cs accumulated in the killifish's meat was shown not to be binding to protein's composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with 137 Cs in samples and ammonium phosphomolybdate, 137 Cs in the NPNC fraction of the killifish's meat was not almost different from those of each control and 137 CsCl solution. (author)

  17. Expression of c-fos gene in central nervous system of adult medaka (Oryzias latipes) after hypergravity stimulation

    Shimomura, S.; Ijiri, K.

    The immediate-early genes serve as useful neurobiological tools for mapping brain activity induced by a sensory stimulation. In this study, we have examined brain activity related to gravity perception of medaka (Oryzias latipes) by use of c-fos. The gene, which is homologous to the c-fos genes of other vertebrates, was identified in medaka. Functionally important domains are highly conserved among all the vertebrate species analyzed. Intraperitoneal administration of kainic acid transiently induced the c-fos mRNAs in medaka brain. The results indicate that the expression of c-fos can be utilized as a suitable anatomical marker for the increased neural activities in the central nervous system of medaka. Fish were continuously exposed to 3G hypergravity by centrifugation. Investigation of c-fos mRNA expression showed that c-fos mRNA significantly increased 30 minutes after a start of 3G exposure. The distribution of its transcripts within brains was analyzed by an in situ hybridization method. The 3G-treated medakas displayed c-fos positive cells in their brainstem regions, which are related to vestibular function, such as torus semicircularis, posterior octavu nucleus, nucleus tangentialis and inferior olive. Our results established the method to trace the activated area in the fish brain following gravity stimulation. The method will be a useful tool for understanding gravity perception in the brain.

  18. Impacts of low dose rate irradiation on the fertility, fecundity and hatchling survival of Japanese rice fish (medaka, Oryzias latipes)

    Hinton, T.G.; Coughlin, D.P.; Marsh, L.C.; Yi, Yi; Winn, R.

    2004-01-01

    A renewed international interest in the effects on biota from low dose rate irradiation has recently occurred. Much of that interest is centered on the relevance of previously accepted dose rate guidelines (e.g. 10 mGy d -1 for aquatic biota) suggested by the ICRP and IAEA. All parties concerned seem to agree that additional data are needed on population level impacts from chronic low-level exposures to radionuclides. Using a Low Dose Rate Irradiation Facility (LoDIF), we conducted an experiment on the fecundity, fertility and hatchling survival of Japanese Rice Fish (medaka, Oryzias latipes). Fish were exposed externally to 137 Cs from juvenile through adulthood at mean dose rates of 3.5, 35 and 350 mGy d -1 . Fish were bred at maturity and the following endpoints were examined: 1) the number of eggs produced; 2) the percent of eggs that hatched; and 3) the survival of hatchlings 20-days post hatch. The influence of gender was examined by breeding irradiated males with control females; control males with irradiated females; irradiated males with irradiated females; and control males with control females. The data contribute to our understanding the impacts of low dose rate irradiation. (author)

  19. Evaluation on potential for assessing indoor formaldehyde using biosensor system based on swimming behavior of Japanese medaka (oryzias latipes)

    Kim, Jonghun [Department of Architecture, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505 (Japan); Kato, Shinsuke; Tatsuma, Tetsu [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505 (Japan); Takeuchi, Kenichiro [Sumitomo Forestry Co., Ltd. (Japan); Kang, Ik Joon [Aquatic Biomonitoring and Environmental Laboratory, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 (Japan)

    2011-04-15

    In order to develop an early-warning biosensor system for predicting the impact on health of long-term and low-level exposure to indoor chemical compounds, e.g. volatile organic compounds (VOCs), we evaluated the potential for assessing indoor air quality using the biosensor system based on the swimming behavior of Japanese medaka (oryzias latipes) as an indicator of indoor air quality in the beginning. As a technology to dissolve chemical compounds into water efficiently, a micro bubble generator was introduced. The test chemical was formaldehyde which is a representative of chemical compounds existing indoors. The result of the measuring solubility of formaldehyde was that formaldehyde concentration in water was raised to 0.12 mg/L when 1.0 mg/m{sup 3} of formaldehyde in air was bubbled for approximately 44 h. The correlation between the 0.1 mg/L of formaldehyde in water, which is roughly equivalent to 0.83 mg/m{sup 3} of formaldehyde in air, and the swimming activities of medaka was investigated. The fish showed abnormal behavior compared to one under a control treatment, e.g. the body movement distance decreased and the duration time near the upper water column increased significantly. It was verified that it is possible to detect concentrations of formaldehyde of 0.83 mg/m{sup 3} in indoor air using this proposed biosensor system. (author)

  20. Verification of responses of Japanese medaka (Oryzias latipes) to anti-androgens, vinclozolin and flutamide, in short-term assays.

    Nakamura, Ataru; Takanobu, Hitomi; Tamura, Ikumi; Yamamuro, Masumi; Iguchi, Taisen; Tatarazako, Norihisa

    2014-05-01

    Various testing methods for the detection of the endocrine disruptive activities of chemicals have been developed in freshwater fish species. However, a few relatively easier specific methods for detecting anti-androgenic activities are available for fish. The aim of this study was to verify the papillary process in Japanese medaka (Oryzias latipes) as an indicator of the anti-androgenic activity of chemicals. Japanese medaka were exposed to two types of anti-androgenic compounds, vinclozolin and flutamide, using two short-term assays; one was conformed to the existing short-term reproduction assay using adult fish (adult test) and the other was a test based on the same methods but using juvenile fish at the beginning of exposure (juvenile test). Significant decreases in male papillary processes were observed in the juvenile test treated with the highest concentration of both antiandrogens (640 µg l(-1) vinclozolin and 1000 µg l(-1) flutamide); however, no significant effects were observed in the adult test. Consequently, our results indicate that papillary processes in Japanese medaka can be used as the end-point for screening the anti-androgenic activity of chemicals using juvenile fish for a specific period based on the existing short-term reproduction assay. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Effects of the antiandrogens, vinclozolin and cyproterone acetate on gonadal development in the Japanese medaka (Oryzias latipes).

    Kiparissis, Yiannis; Metcalfe, Tracy L; Balch, Gordon C; Metcalfe, Chris D

    2003-05-29

    This study was focused on determining the effects of exposure to antiandrogens on the gonadal development of Japanese medaka (Oryzias latipes). Test compounds included the fungicide, vinclozolin and the clinical antiandrogen, cyproterone acetate. Newly hatched medaka were exposed to aqueous solutions of vinclozolin (2500 microg/l) and the vinclozolin fungicide formulation, Ronilan (1000 and 5000 microg/l) and cyproterone acetate (1 and 10 microg/l), for 3 months. Histological evaluation of the gonadal tissues of exposed fish indicated that the 5000 microg/l concentration of the vinclozolin formulation (Ronilan) induced a low incidence of intersex (i.e. testis-ova) and the 2500 microg/l concentration of vinclozolin-affected spermatogenesis in males. Also, the vinclozolin treatments induced moderate ovarian atresia. Cyproterone acetate also induced a low incidence of testis-ova, but in contrast to the vinclozolin treatment the amount of ovarian tissue in the testis-ova was equal to or greater than the amount of testicular tissue. In the cyproterone acetate treatments, both oogenesis and spermatogenesis were moderately inhibited at all test concentrations. The results of this study indicate that antiandrogens have the potential to alter testicular development and gametogenesis in fish. However, research is needed to determine the mechanisms by which antiandrogens affect fish.

  2. Effects of alachlor on the early development and induction of estrogen-responsive genes in Medaka, Oryzias latipes

    Lee, C.; Ryu, J.; Park, S.Y.; Choi, K.; Jeon, S.H.; Na, J.G.; Rhee, D.G. [National Inst. of Environmental Research, Incheon (Korea)

    2004-09-15

    Alachlor is an acetanilide herbicide used to control annual grasses and weeds in field corn, soybeans, and peanuts. It is a selective systemic herbicide, absorbed by germinating shoots and by roots. Although the specific pathways are not exactly understood, the acetanilide herbicides apparently interfere with several physiological processes including biosynthesis of lipids, proteins and flavonoids. These herbicides are widely used in agriculture and are commonly detected in surface water and groundwater. Alachlor has a relatively low acute toxicity, however, repeated exposure has been reported to cause hepatotoxicity, irreversible uveal degeneration and tumour formation in some animals. Besides alachlor is one of the herbicides reported to have endocrine disrupting effects. 2,4-D, 2,4,5-T, amitrole and atrazine also belong to these types of herbicides. Alachlor is a strongly suspected endocrine disruptor in that it is listed by EPA and the World Wildlife Fund [WWF] as a potential endocrine disrupting chemical. Many mammalian and aquatic toxicological studies with alachlor were performed under the conditions of acute, subacute and chronic experiment. However, not many studies using fish have been carried out with the purpose of screening and testing of endocrine disrupting effects of alachlor. The purpose of this study was to determine the effects of alachlor on the early morphological development of medaka (Oryzias latipes). Embryonic growth, deformation and hatching success were determined to see the effects of this chemical. Also, we tried to measure the estrogenic activity of alachlor using the ELISA and RT-PCR methods. By using these techniques, we evaluated the induction of the estrogen-responsive genes, vitellogenin (precursor of yolk protein) and choriogenin (precursor of egg envelope protein) in male medaka exposed to alachlor.

  3. Fluorescence in situ hybridization techniques (FISH) to detect changes in CYP19a gene expression of Japanese medaka (Oryzias latipes)

    Park, June-Woo; Tompsett, Amber; Zhang, Xiaowei; Newsted, John L.; Jones, Paul D.; Au, Doris; Kong, Richard; Wu, Rudolf S.S.; Giesy, John P.; Hecker, Markus

    2008-01-01

    The aim of this study was to develop a sensitive in situ hybridization methodology using fluorescence-labeled riboprobes (FISH) that allows for the evaluation of gene expression profiles simultaneously in multiple target tissues of whole fish sections of Japanese medaka (Oryzias latipes). To date FISH methods have been limited in their application due to autofluorescence of tissues, fixatives or other components of the hybridization procedure. An optimized FISH method, based on confocal fluorescence microscopy was developed to reduce the autofluorescence signal. Because of its tissue- and gender-specific expression and relevance in studies of endocrine disruption, gonadal aromatase (CYP19a) was used as a model gene. The in situ hybridization (ISH) system was validated in a test exposure with the aromatase inhibitor fadrozole. The optimized FISH method revealed tissue-specific expression of the CYP19a gene. Furthermore, the assay could differentiate the abundance of CYP19a mRNA among cell types. Expression of CYP19a was primarily associated with early stage oocytes, and expression gradually decreased with increasing maturation. No expression of CYP19a mRNA was observed in other tissues such as brain, liver, or testes. Fadrozole (100 μg/L) caused up-regulation of CYP19a expression, a trend that was confirmed by RT-PCR analysis on excised tissues. In a combination approach with gonad histology, it could be shown that the increase in CYP19a expression as measured by RT-PCR on a whole tissue basis was due to a combination of both increases in numbers of CYP19a-containing cells and an increase in the amount of CYP19a mRNA present in the cells

  4. Sound production in Japanese medaka (Oryzias latipes) and its alteration by exposure to aldicarb and copper sulfate.

    Kang, Ik Joon; Qiu, Xuchun; Moroishi, Junya; Oshima, Yuji

    2017-08-01

    This study is the first to report sound production in Japanese medaka (Oryzias latipes). Sound production was affected by exposure to the carbamate insecticide (aldicarb) and heavy-metal compound (copper sulfate). Medaka were exposed at four concentrations (aldicarb: 0, 0.25, 0.5, and 1 mg L -1 ; copper sulfate: 0, 0.5, 1, and 2 mg L -1 ), and sound characteristics were monitored for 5 h after exposure. We observed constant average interpulse intervals (approx 0.2 s) in all test groups before exposure, and in the control groups throughout the experiment. The average interpulse interval became significantly longer during the recording periods after 50 min of exposure to aldicarb, and reached a length of more than 0.3 s during the recording periods after 120 min exposure. Most medaka fish stopped to produce sound after 50 min of exposure to copper sulfate at 1 and 2 mg L -1 , resulting in significantly declined number of sound pulses and pulse groups. Relative shortened interpulse intervals of sound were occasionally observed in medaka fish exposed to 0.5 mg L -1 copper sulfate. These alternations in sound characteristics due to toxicants exposure suggested that they might impair acoustic communication of medaka fish, which may be important for their reproduction and survival. Our results suggested that using acoustic changes of medaka has potential to monitor precipitate water pollutions, such as intentional poisoning or accidental leakage of industrial waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Recovery from reproductive and morphological abnormalities in medaka (Oryzias latipes) following a 14-day exposure to diclofenac.

    Yokota, Hirofumi; Higashi, Kaho; Hanada, Erina; Matsuzaki, Ei; Tsuruda, Yukinari; Suzuki, Tomoko; Nakano, Eiko; Eguchi, Sayaka

    2017-12-01

    Mating pairs of medaka (Oryzias latipes) were exposed to diclofenac at measured concentrations of 0 (control), 7.1, 37, and 78 μg/L for 14 d under static-renewal conditions. Effects on reproductive success, as well as morphological abnormalities, of the fish were assessed. During the exposure period, both fecundity and fertility were significantly decreased in the 37- and 78-μg/L treatment groups, and swollen abdomens in females were observed in all exposure groups. Notably, a defect of the lower jaw was also observed in 4 male fish: 2 at 37 μg/L and 2 at 78 μg/L of diclofenac. Subsequently, we investigated whether the reproductive and morphological abnormalities induced by diclofenac would be permanent or reversible once the medaka were returned to clean water. The reproductive ability of paired medaka was gradually restored to fish that were cultured in clean water for 14 d. After this period in clean water, we also observed a noticeable decrease in swollen abdomens in females; however, mandibular defects in the males remained, even after the 14-d recovery period. Radiographic and histochemical examinations revealed that diclofenac might affect bone remodeling in the lower jaw of male medaka because of a disruption in osteoclast function. These results suggest that reproductive impairments in pairs of medaka exposed to diclofenac may be reversible but that skeletal deformities (i.e., mandibular defect) in males may be persistent. Environ Toxicol Chem 2017;36:3277-3283. © 2017 SETAC. © 2017 SETAC.

  6. Analysis of the Ush2a gene in medaka fish (Oryzias latipes.

    Elena Aller

    Full Text Available Patients suffering from Usher syndrome (USH exhibit sensorineural hearing loss, retinitis pigmentosa (RP and, in some cases, vestibular dysfunction. USH is the most common genetic disorder affecting hearing and vision and is included in a group of hereditary pathologies associated with defects in ciliary function known as ciliopathies. This syndrome is clinically classified into three types: USH1, USH2 and USH3. USH2 accounts for well over one-half of all Usher cases and mutations in the USH2A gene are responsible for the majority of USH2 cases, but also for atypical Usher syndrome and recessive non-syndromic RP. Because medaka fish (Oryzias latypes is an attractive model organism for genetic-based studies in biomedical research, we investigated the expression and function of the USH2A ortholog in this teleost species. Ol-Ush2a encodes a protein of 5.445 aa codons, containing the same motif arrangement as the human USH2A. Ol-Ush2a is expressed during early stages of medaka fish development and persists into adulthood. Temporal Ol-Ush2a expression analysis using whole mount in situ hybridization (WMISH on embryos at different embryonic stages showed restricted expression to otoliths and retina, suggesting that Ol-Ush2a might play a conserved role in the development and/or maintenance of retinal photoreceptors and cochlear hair cells. Knockdown of Ol-Ush2a in medaka fish caused embryonic developmental defects (small eyes and heads, otolith malformations and shortened bodies with curved tails resulting in late embryo lethality. These embryonic defects, observed in our study and in other ciliary disorders, are associated with defective cell movement specifically implicated in left-right (LR axis determination and planar cell polarity (PCP.

  7. Analysis of the Ush2a gene in medaka fish (Oryzias latipes).

    Aller, Elena; Sánchez-Sánchez, Ana V; Chicote, Javier U; García-García, Gema; Udaondo, Patricia; Cavallé, Laura; Piquer-Gil, Marina; García-España, Antonio; Díaz-Llopis, Manuel; Millán, José M; Mullor, José L

    2013-01-01

    Patients suffering from Usher syndrome (USH) exhibit sensorineural hearing loss, retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. USH is the most common genetic disorder affecting hearing and vision and is included in a group of hereditary pathologies associated with defects in ciliary function known as ciliopathies. This syndrome is clinically classified into three types: USH1, USH2 and USH3. USH2 accounts for well over one-half of all Usher cases and mutations in the USH2A gene are responsible for the majority of USH2 cases, but also for atypical Usher syndrome and recessive non-syndromic RP. Because medaka fish (Oryzias latypes) is an attractive model organism for genetic-based studies in biomedical research, we investigated the expression and function of the USH2A ortholog in this teleost species. Ol-Ush2a encodes a protein of 5.445 aa codons, containing the same motif arrangement as the human USH2A. Ol-Ush2a is expressed during early stages of medaka fish development and persists into adulthood. Temporal Ol-Ush2a expression analysis using whole mount in situ hybridization (WMISH) on embryos at different embryonic stages showed restricted expression to otoliths and retina, suggesting that Ol-Ush2a might play a conserved role in the development and/or maintenance of retinal photoreceptors and cochlear hair cells. Knockdown of Ol-Ush2a in medaka fish caused embryonic developmental defects (small eyes and heads, otolith malformations and shortened bodies with curved tails) resulting in late embryo lethality. These embryonic defects, observed in our study and in other ciliary disorders, are associated with defective cell movement specifically implicated in left-right (LR) axis determination and planar cell polarity (PCP).

  8. Using CRISPR/Cas9-mediated gene editing to further explore growth and trade-off effects in myostatin-mutated F4 medaka (Oryzias latipes).

    Yeh, Ying-Chun; Kinoshita, Masato; Ng, Tze Hann; Chang, Yu-Hsuan; Maekawa, Shun; Chiang, Yi-An; Aoki, Takashi; Wang, Han-Ching

    2017-09-12

    Myostatin (MSTN) suppresses skeletal muscle development and growth in mammals, but its role in fish is less well understood. Here we used CRISPR/Cas9 to mutate the MSTN gene in medaka (Oryzias latipes) and evaluate subsequent growth performance. We produced mutant F0 fish that carried different frameshifts in the OlMSTN coding sequence and confirmed the heritability of the mutant genotypes to the F1 generation. Two F1 fish with the same heterozygous frame-shifted genomic mutations (a 22 bp insertion in one allele; a 32 bp insertion in the other) were then crossbred to produce subsequent generations (F2~F5). Body length and weight of the MSTN -/- F4 medaka were significantly higher than in the wild type fish, and muscle fiber density in the inner and outer compartments of the epaxial muscles was decreased, suggesting that MSTN null mutation induces muscle hypertrophy. From 3~4 weeks post hatching (wph), the expression of three major myogenic related factors (MRFs), MyoD, Myf5 and Myogenin, was also significantly upregulated. Some medaka had a spinal deformity, and we also observed a trade-off between growth and immunity in MSTN -/- F4 medaka. Reproduction was unimpaired in the fast-growth phenotypes.

  9. Distribution of the orphan nuclear receptor Nurr1 in medaka (Oryzias latipes): cues to the definition of homologous cell groups in the vertebrate brain.

    Kapsimali, M; Bourrat, F; Vernier, P

    2001-03-12

    The orphan nuclear receptor Nurr1 has been extensively studied in mammals and shown to contribute to the differentiation of several cell phenotypes in the nervous and endocrine systems. In this study, the gene homologous to the mammalian Nurr1 (NR4A2) was isolated in the teleost fish medaka (Oryzias latipes), and the distribution of its transcripts was analyzed within brains of embryos and adults. Nurr1 has a widespread distribution in the medaka brain. Large amounts of Nurr1 transcripts were found in the intermediate nucleus of the ventral telencephalon, preoptic magnocellular nucleus, ventral habenula, nucleus of the periventricular posterior tuberculum, and nuclei of glossopharyngeal and vagus nerves. To search for homologous cell groups between teleost fish and tetrapods brains, the co-localization of Nurr1 and tyrosine hydroxylase (TH) transcripts was analyzed. Neither Nurr1 nor TH expression was detected in the ventral midbrain, but both transcripts were present in the periventricular nucleus of the posterior tuberculum. This observation supports the hypothesis that this nucleus is homologous to dopaminergic mesencephalic nuclei of mammals. The presence of Nurr1 in the preoptic magnocellular nucleus of medaka and paraventricular hypothalamic nucleus of mammals reinforces the hypothesis of homology between these areas. TH and Nurr1 transcripts are also co-localized, among others, in the nucleus of the paraventricular organ and nucleus of the vagus nerve. This work suggests that the differentiating role of Nurr1 in the central nervous system is conserved in gnathostomes. Copyright 2001 Wiley-Liss, Inc.

  10. Nanosecond pulsed electric field suppresses development of eyes and germ cells through blocking synthesis of retinoic acid in Medaka (Oryzias latipes.

    Eri Shiraishi

    Full Text Available Application of nanosecond pulsed electric fields (nsPEFs has attracted rising attention in various scientific fields including medical, pharmacological, and biological sciences, although its effects and molecular mechanisms leading to the effects remain poorly understood. Here, we show that a single, high-intensity (10-30 kV/cm, 60-ns PEF exposure affects gene expression and impairs development of eyes and germ cells in medaka (Oryzias latipes. Exposure of early blastula stage embryos to nsPEF down-regulated the expression of several transcription factors which are essential for eye development, causing abnormal eye formation. Moreover, the majority of the exposed genetic female embryos showed a fewer number of germ cells similar to that of the control (unexposed genetic male at 9 days post-fertilization (dpf. However, all-trans retinoic acid (atRA treatment following the exposure rescued proliferation of germ cells and resumption of normal eye development, suggesting that the phenotypes induced by nsPEF are caused by a decrease of retinoic acid levels. These results confirm that nsPEFs induce novel effects during embryogenesis in medaka.

  11. The vasa-like gene, olvas, identifies the migration path of primordial germ cells during embryonic body formation stage in the medaka, Oryzias latipes.

    Shinomiya, A; Tanaka, M; Kobayashi, T; Nagahama, Y; Hamaguchi, S

    2000-08-01

    The medaka homolog of the Drosophila vasa gene, olvas (Oryzias latipes vas) was obtained using polymerase chain reaction of medaka cDNA from the testis and ovary. The spatio-temporal expression pattern of olvas transcripts was observed by in situ hybridization on gonads and embryos. The transcripts for olvas were exclusively detected in the cytoplasm of germ cells in the testis and ovary, not in gonadal somatic cells. In the early developmental stages, each blastomere possessed the maternal transcripts of olvas, which disappeared during gastrula stages. At the late gastrula stage, specific expression of olvas was observed only in germline cells located at the posterior shield. Embryos after the hybridization were examined histologically, and the distribution and migration path of primordial germ cells (PGC) during early stages of embryonic-body formation were revealed using the olvas gene as a germline cell marker. The PGC were translocated from the posterior shield to both sides of the embryonic body via the inner embryonic body in the medaka.

  12. Irradiation-injured brain tissues can self-renew in the absence of the pivotal tumor suppressor p53 in the medaka (Oryzias latipes) embryo

    Yasuda, Takako; Nagata, Kento; Igarashi, Kento; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi; Kimori, Yoshitaka

    2016-01-01

    The tumor suppressor protein, p53, plays pivotal roles in regulating apoptosis and proliferation in the embryonic and adult central nervous system (CNS) following neuronal injuries such as those induced by ionizing radiation. There is increasing evidence that p53 negatively regulates the self-renewal of neural stem cells in the adult murine brain; however, it is still unknown whether p53 is essential for self-renewal in the injured developing CNS. Previously, we demonstrated that the numbers of apoptotic cells in medaka (Oryzias latipes) embryos decreased in the absence of p53 at 12-24 h after irradiation with 10-Gy gamma rays. Here, we used histology to examine the later morphological development of the irradiated medaka brain. In p53-deficient larvae, the embryonic brain possessed similar vacuoles in the brain and retina, although the vacuoles were much smaller and fewer than those found in wild-type embryos. At the time of hatching (6 days after irradiation), no brain abnormality was observed. In contrast, severe disorganized neuronal arrangements were still present in the brain of irradiated wild-type embryos. Our present results demonstrated that self-renewal of the brain tissue completed faster in the absence of p53 than wild type at the time of hatching because p53 reduces the acute severe neural apoptosis induced by irradiation, suggesting that p53 is not essential for tissue self-renewal in developing brain. (author)

  13. A protocol for adult somatic cell nuclear transfer in medaka fish (Oryzias latipes) with a high rate of viable clone formation.

    Bubenshchikova, Ekaterina; Kaftanovskaya, Elena; Adachi, Tomoko; Hashimoto, Hisashi; Kinoshita, Masato; Wakamatsu, Yuko

    2013-12-01

    Previously, we successfully generated fully grown, cloned medaka (the Japanese rice fish, Oryzias latipes) using donor nuclei from primary culture cells of adult caudal fin tissue and nonenucleated recipient eggs that were heat shock-treated to induce diploidization of the nuclei. However, the mechanism of clone formation using this method is unknown, and the rate of adult clone formation is not high enough for studies in basic and applied sciences. To gain insight into the mechanism and increase the success rate of this method of clone formation, we tested two distinct nuclear transfer protocols. In one protocol, the timing of transfer of donor nuclei was changed, and in the other, the size of the donor cells was changed; each protocol was based on our original methodology. Ultimately, we obtained an unexpectedly high rate of adult clone formation using the protocol that differed with respect to the timing of donor nuclei transfer. Specifically, 17% of the transplants that developed to the blastula stage ultimately developed into adult clones. The success rate with this method was 13 times higher than that obtained using the original method. Analyses focusing on the reasons for this high success rate of clone formation will help to elucidate the mechanism of clone formation that occurs with this method.

  14. Radioecological studies of {sup 137}Cs in limnological ecosystems. Biochemical states of {sup 137}Cs accumulated in killifish (Medaka, Oryzias latipes) meat

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Institute of Public Health, Urawa (Japan); Izumo, Yoshiro; Nakamura, Fumio

    1997-07-01

    Biochemical states of {sup 137}Cs accumulated in killifish`s (Medaka, Oryzias latipes) meat were investigated in order to elucidate the accumulation mechanism of the radionuclide in goldfish, Carassius auratus auratus, examined in our preceding report. Most of {sup 137}Cs radioactivity in the killifish`s raw meat accumulated this radionuclide in the radioactive freshwater, were found in the non-protein nitrogenous compound (NPNC) fraction (>92%), also in the killifish`s control raw meat mixed with {sup 137}Cs, the difference between both meat samples was not clear. As the results of gel filtration profiles on Sephadex G-25 for the NPNC fraction of these meats, each only one radioactive peak was shown, also similar to {sup 137}CsCl solution. Moreover, these peaks appeared at the same position. On the other hand, the peak positions absorbed at OD{sub 280nm} in the samples were different from those of each radioactive peak. It was so suggested that {sup 137}Cs accumulated in the killifish`s meat was shown not to be binding to protein`s composition. Furthermore, as the results on thin-layer chromatography, ion-exchange resin chromatography and reaction with {sup 137}Cs in samples and ammonium phosphomolybdate, {sup 137}Cs in the NPNC fraction of the killifish`s meat was not almost different from those of each control and {sup 137}CsCl solution. (author)

  15. Effects of silver nanoparticles on the development and histopathology biomarkers of Japanese medaka (Oryzias latipes) using the partial-life test.

    Wu, Yuan; Zhou, Qunfang; Li, Hongcheng; Liu, Wei; Wang, Thanh; Jiang, Guibin

    2010-10-15

    Silver nanoparticles (AgNPs) have emerged as an important class of nanomaterials and are currently used in a wide range of industrial and commercial applications. This has caused increasing concern about their effects on the environment and to human health. Using Japanese medaka (Oryzias latipes) at early-life stages as experimental models, the developmental toxicity of silver nanoparticles was investigated following exposure to 100-1000 μg/L homogeneously dispersed AgNPs for 70 days, and developmental endpoints were evaluated by microscopy during embryonic, larval and juvenile stages of development in medaka. Meanwhile, histopathological changes in the larval eye were evaluated. Retarded development and reduced pigmentation were observed in the treated embryos by AgNPs at high concentrations (≥ 400 μg/L). Maximum width of the optic tectum, as an indicator of midbrain development, decreased significantly in a dose-related manner. Furthermore, silver nanoparticles exposure at all concentrations induced a variety of morphological malformations such as edema, spinal abnormalities, finfold abnormalities, heart malformations and eye defects. Histopathological observations also confirmed the occurrence of abnormal eye development induced by AgNPs. The data showed non-linear or U-shaped dose-response patterns for growth retardation at 5 days of postfertilization, as well as the incidence of abnormalities. Preliminary results suggested that the developmental process of medaka may be affected by exposure to silver nanoparticles. Morphological abnormalities in early-life stages of medaka showed the potential developmental toxicities of silver nanoparticles. Further research should be focused on the mechanisms of developmental toxicity in fish exposed to silver nanoparticles. Crown Copyright 2009. Published by Elsevier B.V. All rights reserved.

  16. p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.

    Sun, Jianxian; Wang, Chen; Peng, Hui; Zheng, Guomao; Zhang, Shiyi; Hu, Jianying

    2016-01-05

    Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.

  17. Development of a possible nonmammalian test system for radiation-induced germ-cell mutagenesis using a fish, the Japanese medaka (Oryzias latipes)

    Shima, A.; Shimada, A.

    1991-01-01

    To develop a specific-locus test (SLT) system for environmental mutagenesis using vertebrate species other than the mouse, we first established a tester stock of the fish medaka (Oryzias latipes) that is homozygous recessive at three loci. The phenotypic expression of these loci can be easily recognized early in embryonic development by observation through the transparent egg membrane. We irradiated wild-type males with 137Cs gamma-rays to determine the dose-response relationships for dominant lethal and specific-locus mutations induced in sperm, spermatids, and spermatogonia. Through observation of 322,666 loci in control offspring and 374,026 loci in offspring obtained from 0.64-, 4.75-, or 9.50-Gy-irradiated gametes, specific-locus mutations were phenotypically detected during early development. These putative mutations, designated total mutation, can be recognized only in embryos of oviparous animals. The developmental fate of these mutant embryos was precisely followed. During subsequent embryonic development, a large fraction died and thus was unavailable for test-crossing, which was used to identify viable mutations. Our medaka SLT system demonstrates that the vast majority of total mutations is associated with dominant lethal mutations. Thus far only one spontaneous viable mutation has been observed, so that all doubling calculations involving this endpoint carry a large error. With these reservations, however, we conclude that the quantitative data so far obtained from the medaka SLT are quite comparable to those from the mouse SLT and, hence, indicate the validity of the medaka SLT as a possible nonmammalian test system

  18. Quantitative structure-activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes).

    Lin, Hongkang; Morandi, Garrett D; Brown, R Stephen; Snieckus, Victor; Rantanen, Toni; Jørgensen, Kåre B; Hodson, Peter V

    2015-02-01

    Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and logKow values provided a rough estimation of structure-activity relationships for alkyl-PAHs, but Kow alone did not provide a complete explanation of the chronic toxicity of alkyl PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish

    Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X±SD) at log I=1.96 (photopic) varied from 37.2±1.6 cycles/s in young adults to 18.6±1.6 cycles/s in young larvae 10 days posthatch. At log I=−2.54 (scotopic), flicker fusion thresholds varied from 5.8±0.7 cycles/s in young adults to 1.7±0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche.

  20. Alteration of development and gene expression induced by in ovo-nanoinjection of 3-hydroxybenzo[c]phenanthrene into Japanese medaka (Oryzias latipes) embryos.

    Chen, Kun; Tsutsumi, Yuki; Yoshitake, Shuhei; Qiu, Xuchun; Xu, Hai; Hashiguchi, Yasuyuki; Honda, Masato; Tashiro, Kosuke; Nakayama, Kei; Hano, Takeshi; Suzuki, Nobuo; Hayakawa, Kazuichi; Shimasaki, Yohei; Oshima, Yuji

    2017-01-01

    Benzo[c]phenanthrene (BcP) is a highly toxic polycyclic aromatic hydrocarbon (PAHs) found throughout the environment. In fish, it is metabolized to 3-hydroxybenzo[c]phenanthrene (3-OHBcP). In the present study, we observed the effects of 1nM 3-OHBcP on the development and gene expression of Japanese medaka (Oryzias latipes) embryos. Embryos were nanoinjected with the chemical after fertilization. Survival, developmental stage, and heart rate of the embryos were observed, and gene expression differences were quantified by messenger RNA sequencing (mRNA-Seq). The exposure to 1nM 3-OHBcP accelerated the development of medaka embryos on the 1st, 4th, and 6th days post fertilization (dpf), and increased heart rates significantly on the 5th dpf. Physical development differences of exposed medaka embryos were consistent with the gene expression profiles of the mRNA-Seq results for the 3rd dpf, which show that the expression of 780 genes differed significantly between the solvent control and 1nM 3-OHBcP exposure groups. The obvious expression changes in the exposure group were found for genes involved in organ formation (eye, muscle, heart), energy supply (ATPase and ATP synthase), and stress-response (heat shock protein genes). The acceleration of development and increased heart rate, which were consistent with the changes in mRNA expression, suggested that 3-OHBcP affects the development of medaka embryos. The observation on the developmental stages and heart beat, in ovo-nanoinjection and mRNA-Seq may be efficient tools to evaluate the effects of chemicals on embryos. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Carbonic anhydrase 2-like and Na⁺-K⁺-ATPase α gene expression in medaka (Oryzias latipes) under carbonate alkalinity stress.

    Yao, Zongli; Lai, Qifang; Hao, Zhuoran; Chen, Ling; Lin, Tingting; Zhou, Kai; Wang, Hui

    2015-12-01

    High carbonate alkalinity is one of the major stress factors for living organisms in saline-alkaline water areas. Acute and chronic effects of carbonate alkalinity on expression of two genes, carbonic anhydrase 2-like (CA2-like) and Na(+)-K(+)-ATPase α subunit (NKA-α) mRNA in medaka (Oryzias latipes) were evaluated to better understand the responses important for coping with a carbonate alkalinity stress. In the acute exposure experiment, the expression of CA2-like and NKA-α mRNA in the gill and kidney of medaka were examined from 0 h to 7 days exposed to 30.4 mM carbonate alkalinity water. Exposure to high carbonate alkalinity resulted in a transitory alkalosis, followed by a transient increase in gill and kidney CA2-like and NKA-α mRNA expression. In the chronic exposure experiment, the expression of these two genes was examined in the gill and kidney at 50 days post-exposure to six different carbonate alkalinity concentrations ranging from 1.5 to 30.4 mM. Gill and kidney CA2-like mRNA levels in 30.4 mM were approximately 10 and 30 times higher than that of the control (1.5 mM), respectively. Less differences were found in NKA-α expression in the 50-days exposure. The results indicate that when transferred to high carbonate alkalinity water, a transitory alkalosis may occur in medaka, followed by compensatory acid-base and ion regulatory responses. Thus, CA2-like and NKA-α are at least two of the important factors that contribute to the regulation of alkalinity stress.

  2. Benzo[a]pyrene-induced immunotoxicity in Japanese medaka (Oryzias latipes): relationship between lymphoid CYP1A activity and humoral immune suppression

    Carlson, E.A.; Li, Y.; Zelikoff, J.T.

    2004-01-01

    Exposure to the environmental contaminant benzo[a]pyrene (BaP) results in suppression of immune function in both mammalian and fish species. This laboratory has previously demonstrated that a single intraperitoneal (IP) injection of BaP reduced lymphocyte proliferation, phagocyte-mediated superoxide generation, and antibody-forming cell (AFC) numbers in Japanese medaka (Oryzias latipes). The objective of the current study was to determine the role of BaP metabolism in the observed immunosuppression. Results from rodent studies have suggested that BaP elicits its immunotoxic effects via upregulation of cytochrome P4501A1 (CYP1A1) and the subsequent production of immunosuppressive BaP metabolites. In this study, exposure of medaka to 200 μg BaP/g BW significantly induced CYP1A expression or activity within lymphoid tissue 48 h post-IP injection; induction was observed specifically within distinct subpopulations of kidney mononuclear cells. Concurrent injection of fish with BaP and the CYP1A1 inhibitors α-naphthoflavone (ANF) or dehydroepiandrosterone (DHEA) resulted in inhibition of renal EROD activity and amelioration of BaP-induced suppression of medaka AFC numbers. Results of this study suggest that (1) BaP-induced suppression of medaka humoral immunity relies upon the CYP1A-catalyzed production of immunotoxic BaP metabolites and (2) BaP metabolites may be created in situ, directly by specific cells within kidney lymphoid tissue. Thus, apparently, mechanisms involved in BaP-induced immunosuppression have been phylogenetically conserved from fish to mammals

  3. Effects of benzophenone-3 exposure on endocrine disruption and reproduction of Japanese medaka (Oryzias latipes)—A two generation exposure study

    Kim, Sujin; Jung, Dawoon; Kho, Younglim; Choi, Kyungho

    2014-01-01

    Highlights: • Exposure to BP-3 led to adverse reproduction effects on Japanese medaka at 26 μg/L. • Changes in sex hormones and steroidogenic gene transcription were observed. • Parental exposure to BP-3 influenced on the growth of second generation fish. - Abstract: Benzophenone-3 (BP-3) has been widely used in sunscreens and cosmetics to protect human skin from the harmful effects of UV irradiation. While BP-3 has been frequently detected in surface waters, sediments and biota, only limited information is available on its in vivo toxicity, particularly in fish. In the present study the endocrine disrupting capacity of BP-3 and its underlying mechanisms were investigated using Japanese medaka (Oryzias latipes). Adult Japanese medaka pairs (F0) were exposed to 0, 4.7, 8.4, 26, or 90 μg/L (or 0, 15, 50, 150, or 500 μg/L of BP-3 based on nominal concentration) for 14 d and its effects on sex steroid hormones, and transcription of various associated genes were determined. Following additional 14 d of exposure, the F1 eggs reproduced were counted and were further exposed to 0, 5.4, 12, or 30 μg/L of BP-3 (or 0, 15, 50, or 150 μg/L based on nominal concentrations) until 30 d after hatching. Chemical analysis of the exposed media confirmed transformation of BP-3 to benzophenone-1 (BP-1), a more potent estrogen agonist. After 14 d of the adult fish exposure, plasma concentrations of testosterone (T) significantly increased in male fish. The 17β-estradiol (E2) to T (E2/T) ratio showed significant decreases in both male and female fish. Overall down-regulation of gonadal steroidogenic genes such as star, cyp11a, cyp17, hsd3b, hsd17b3, and cyp19a was also observed. After 28 d of exposure, the daily average egg reproduction per female was significantly reduced at 26 μg/L of BP-3. However, hatchability of F1 eggs was not affected by continuous exposure. After continued exposure until 30 dph, juvenile fish showed concentration-dependent decrease of condition factor

  4. Quantitative structure–activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes)

    Lin, Hongkang [Department of Biology, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Morandi, Garrett D. [School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Brown, R. Stephen [School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Department of Chemistry, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Snieckus, Victor; Rantanen, Toni [Department of Chemistry, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Jørgensen, Kåre B. [Department of Mathematics and Natural Sciences, University of Stavanger, 4036 Stavanger (Norway); Hodson, Peter V., E-mail: peter.hodson@queensu.ca [Department of Biology, Queen' s University, Kingston, Ontario K7L3N6 (Canada); School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada)

    2015-02-15

    Highlights: • Medaka embryos were exposed to alkyl chrysenes and benzo[a]anthracenes (BAA). • Concentrations were kept constant by partition controlled delivery. • Chrysene was not toxic within solubility limits, in contrast to BAA. • Alkylation increased the toxicity of chrysene and BAA. • Toxicity was related to hydrophobicity and to specific modes of action. - Abstract: Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and log K{sub ow} values provided a rough estimation of structure–activity relationships for alkyl-PAHs, but K{sub ow} alone did not provide

  5. Toxic actions of dinoseb in medaka (Oryzias latipes) embryos as determined by in vivo 31P NMR, HPLC-UV and 1H NMR metabolomics.

    Viant, Mark R; Pincetich, Christopher A; Hinton, David E; Tjeerdema, Ronald S

    2006-03-10

    Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo (31)P NMR, high-pressure liquid chromatography (HPLC)-UV, and (1)H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo (31)P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV; and changes in numerous polar metabolites were characterized by (1)H NMR-based metabolomics. Rangefinding exposures determined two sublethal doses of dinoseb, 50 and 75 ppb, in which embryos survived from 1-day post fertilization (DPF) through the duration of embryogenesis. In vivo (31)P NMR data were acquired from 900 embryos in 0, 50, and 75 ppb dinoseb at 14, 62, and 110 h (n = 6 groups) after initiation of exposure. After 110 h, embryos were observed for normal development and hatching success, then either preserved in 10% formalin for growth analysis or flash frozen and extracted for HPLC-UV and (1)H NMR analysis. Dinoseb exposure at both concentrations resulted in significant declines in [ATP] and [PCr] at 110 h as measured by in vivo (31)P NMR (p fashion. Metabolic effects measured by in vivo (31)P NMR showed a significant increase in orthophosphate levels (P(i); p < 0.05), and significant decreases in [ATP], [PCr] and the PCr/P(i) ratio (p < 0.05). Metabolomics revealed a dose-response relationship between dinoseb and endogenous metabolite changes, with both dinoseb concentrations producing significantly different metabolic profiles from controls (p < 0.05). Metabolic changes included decreased concentrations of ATP, PCr, alanine and tyrosine, and increased concentrations of lactate with medaka embryotoxicity. This study demonstrated that medaka embryos respond to dinoseb with significant changes in metabolism, reduced growth and heart rates, and increased abnormal development and post-exposure mortality. All

  6. Effects of benzophenone-3 exposure on endocrine disruption and reproduction of Japanese medaka (Oryzias latipes)—A two generation exposure study

    Kim, Sujin; Jung, Dawoon [School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of); Kho, Younglim [Department of Health, Environment and Safety, Eulji University, Seongnam 461-713 (Korea, Republic of); Choi, Kyungho, E-mail: kyungho@snu.ac.kr [School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-10-15

    Highlights: • Exposure to BP-3 led to adverse reproduction effects on Japanese medaka at 26 μg/L. • Changes in sex hormones and steroidogenic gene transcription were observed. • Parental exposure to BP-3 influenced on the growth of second generation fish. - Abstract: Benzophenone-3 (BP-3) has been widely used in sunscreens and cosmetics to protect human skin from the harmful effects of UV irradiation. While BP-3 has been frequently detected in surface waters, sediments and biota, only limited information is available on its in vivo toxicity, particularly in fish. In the present study the endocrine disrupting capacity of BP-3 and its underlying mechanisms were investigated using Japanese medaka (Oryzias latipes). Adult Japanese medaka pairs (F0) were exposed to 0, 4.7, 8.4, 26, or 90 μg/L (or 0, 15, 50, 150, or 500 μg/L of BP-3 based on nominal concentration) for 14 d and its effects on sex steroid hormones, and transcription of various associated genes were determined. Following additional 14 d of exposure, the F1 eggs reproduced were counted and were further exposed to 0, 5.4, 12, or 30 μg/L of BP-3 (or 0, 15, 50, or 150 μg/L based on nominal concentrations) until 30 d after hatching. Chemical analysis of the exposed media confirmed transformation of BP-3 to benzophenone-1 (BP-1), a more potent estrogen agonist. After 14 d of the adult fish exposure, plasma concentrations of testosterone (T) significantly increased in male fish. The 17β-estradiol (E2) to T (E2/T) ratio showed significant decreases in both male and female fish. Overall down-regulation of gonadal steroidogenic genes such as star, cyp11a, cyp17, hsd3b, hsd17b3, and cyp19a was also observed. After 28 d of exposure, the daily average egg reproduction per female was significantly reduced at 26 μg/L of BP-3. However, hatchability of F1 eggs was not affected by continuous exposure. After continued exposure until 30 dph, juvenile fish showed concentration-dependent decrease of condition factor

  7. DNA-PK inhibition causes a low level of H2AX phosphorylation and homologous recombination repair in Medaka (Oryzias latipes) cells

    Urushihara, Yusuke; Kobayashi, Junya; Matsumoto, Yoshihisa; Komatsu, Kenshi; Oda, Shoji; Mitani, Hiroshi

    2012-01-01

    Highlights: ► We investigated the effect of DNA-PK inhibition on DSB repair using fish cells. ► A radiation sensitive mutant RIC1 strain showed a low level of DNA-PK activity. ► DNA-PK dysfunction leads defects in HR repair and DNA-PKcs autophosphorylation. ► DNA-PK dysfunction leads a slight increase in the number of 53BP1 foci after DSBs. ► DNA-PK dysfunction leads an alternative NHEJ that depends on 53BP1. -- Abstract: Nonhomologous end joining (NHEJ) and homologous recombination (HR) are known as DNA double-strand break (DSB) repair pathways. It has been reported that DNA-PK, a member of PI3 kinase family, promotes NHEJ and aberrant DNA-PK causes NHEJ deficiency. However, in this study, we demonstrate that a wild-type cell line treated with DNA-PK inhibitor and a mutant cell line with dysfunctional DNA-PK showed decreased HR efficiency in fish cells (Medaka, Oryzias latipes). Previously, we reported that the radiation-sensitive mutant RIC1 strain has a defect in the Histone H2AX phosphorylation after γ-irradiation. Here, we showed that a DNA-PK inhibitor, NU7026, treatment resulted in significant reduction in the number of γH2AX foci after γ-irradiation in wild-type cells, but had no significant effect in RIC1 cells. In addition, RIC1 cells showed significantly lower levels of DNA-PK kinase activity compared with wild-type cells. We investigated NHEJ and HR efficiency after induction of DSBs. Wild-type cells treated with NU7026 and RIC1 cells showed decreased HR efficiency. These results indicated that aberrant DNA-PK causes the reduction in the number of γH2AX foci and HR efficiency in RIC1 cells. We performed phosphorylated DNA-PKcs (Thr2609) and 53BP1 focus assay after γ-irradiation. RIC1 cells showed significant reduction in the number of phosphorylated DNA-PKcs foci and no deference in the number of 53BP1 foci compared with wild-type cells. These results suggest that low level of DNA-PK activity causes aberrant DNA-PKcs autophosphorylation

  8. Evaluation of the effects of ethinylestradiol on sexual differentiation in the olvas-GFP/STII-YI medaka (transgenic Oryzias latipes) strain as estimated by proliferative activity of germ cells

    Hano, Takeshi; Oshima, Yuji; Kinoshita, Masato; Tanaka, Minoru; Mishima, Noriko; Wakamatsu, Yuko; Ozato, Kenjiro; Shimasaki, Yohei; Honjo, Tsuneo

    2011-01-01

    We evaluated the effects of 17(-ethinylestradiol (EE 2 ) on sexual differentiation in transgenic olvas-GFP/STII-YI medaka (Oryzias latipes) in terms of the proliferative activity of germ cells. This strain contains the green fluorescent protein (GFP) gene fused to the regulatory region of the medaka vasa gene, and germ cell-specific expression of GFP can be visualized in living (transparent) individuals. From 0 days post-hatch (0 dph) onwards, juveniles were exposed to graded concentrations of EE 2 (25.2-1710 ng/L) for 35 days. The gonads of live specimens were monitored by measuring their size and calculating their GFP-fluorescence area. GFP-fluorescent area in control females was about 10 times that in control males at 10 days posthatch (dph) whereas the gonadal size of 10 dph males that had been exposed to 158 ng/L of EE 2 significantly increased up to twice the size of control males, indicating that abnormal sexual differentiation towards female might occur in these individuals. Histological examination and identification of the sex-linked marker SL1 indicated that male to female sex reversal occurred at EE 2 exposure ≥45.1 ng/L at 35 dph. These results suggest that observation of proliferative activity of germ cells in the olvas-GFP/STII-YI strain could be applied to facilitated screening fish model to detect adverse effects on sexual differentiation as early as 10 dph juveniles.

  9. Taxonomy Icon Data: Oryzias javanicus [Taxonomy Icon

    Full Text Available Oryzias javanicus Oryzias javanicus Chordata/Vertebrata/Pisciformes Oryzias_javanicus_L.png Oryzias_java...nicus_NL.png Oryzias_javanicus_S.png Oryzias_javanicus_NS.png http://biosciencedbc.jp/t...axonomy_icon/icon.cgi?i=Oryzias+javanicus&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Oryzias+javan...icus&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Oryzias+javanicus&t=S ...http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Oryzias+javanicus&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=77 ...

  10. Radiation effects on lifespan of the fish Oryzias latipes

    Egami, N.

    1979-01-01

    The mortality rate of adult fish exposed to continuous γ-ray irradiation was examined and the results summarized. Initial results into the effects of low-dose γ-irradiation during early developmental stages (one day embryo - 3 month old young) on lifespan, indicate that in this fish the life-shortening effects of radiation are marked at high doses but not at low doses. Age-related histological changes in various tissues have been observed in both irradiated and non-irradiated fish. (Auth.)

  11. NTP carcinogenesis studies of 2,2-bis(bromomethyl)-1,3-propanediol, nitromethane, and 1,2,3-trichloropropane (cas nos. 3296-90-0, 75-52-5, and 96-18-4) in guppies (Poecilia reticulata) and medaka (Oryzias latipes) (Waterborne Studies).

    2005-10-01

    The NTP chose to initiate studies in fish as an exploration of alternate or additional models for examining chemical toxicity and carcinogenicity. The use of small fish species in carcinogenicity testing offered potential advantages as a bioassay test system, including significant savings in cost and time over rodent studies. Large numbers of small fish could be easily maintained in a limited area. The two species chosen for study were guppy (Poecilia reticulata) and medaka (Oryzias latipes), both of which are hardy, easily maintained, and have a low occurrence of background lesions. The three chemicals chosen for study in fish had already been studied by the NTP in rodents, permitting a comparison of results between the two models. Two of the chemicals used (2,2-bis(bromomethyl)-1,3-propanediol and 1,2,3-trichloropropane) were mutagenic and multisite carcinogens in rats and mice. The third chemical, nitromethane, was nonmutagenic with a more modest carcinogenic response in rodents. Male and female guppies and medaka were exposed to 2,2-bis(bromomethyl)- 1,3-propanediol (greater than 99% pure), nitromethane, (greater than 99% pure), or 1,2,3-trichloropropane (99% pure) in aquaria water for up to 16 months. OVERALL STUDY DESIGN: Groups of approximately 220 guppies (two replicates of 110) were maintained in aquaria water containing nominal concentrations of 0, 24, 60, or 150 mg/L 2,2-bis(bromomethyl)-1,3-propanediol; 0, 10, 30, or 70 mg/L nitromethane; or 0, 4.5, 9.0, or 18.0 mg/L 1,2,3-trichloropropane. Groups of approximately 340 medaka (two replicates of 170) were maintained in aquaria water containing 0, 24, 60, or 150 mg/L 2,2-bis(bromomethyl)-1,3-propanediol; 0, 10, 20, or 40 mg/L nitromethane; or 0, 4.5, 9.0, or 18.0 mg/L 1,2,3-trichloropropane. The overall study durations were 16 months for all guppy studies, 14 months for 2,2-bis(bromomethyl)-1,3-propanediol-exposed medaka, and 13 months for nitromethane- and 1,2,3-trichloropropane-exposed medaka. Ten

  12. Artificial fertilization by intracytoplasmic sperm injection in a teleost fish, the medaka (Oryzias latipes).

    Otani, Satoshi; Iwai, Toshiharu; Nakahata, Shingo; Sakai, Chiharu; Yamashita, Masakane

    2009-01-01

    Intracytoplasmic sperm injection (ICSI) is a technique that has been successfully used for assisting reproduction in mammals. However, this method is still not reliable in nonmammalian species, including teleosts. We succeeded in producing medaka individuals by ICSI with a rate of 13.4% (28 hatched embryos out of 209 eggs fertilized by ICSI), the best value reported so far in teleosts, including zebrafish and Nile tilapia. Although the technique was based on that developed for mammalian eggs, some critical modifications were made to adjust it to the medaka egg, which has a thick and hard envelope (the chorion) and a single sperm entry site (the micropyle). Medaka ICSI was performed by injecting a demembranated spermatozoon into an egg cytoplasm through the micropyle 10-15 sec after egg activation induced by a piezo-actuated vibration, the site and timing of sperm penetration being consistent with those in normal fertilization in medaka. To increase the efficiency of ICSI in medaka, we found that the fertilization by ICSI should precisely mimic the fertilization by insemination with intact sperm, both spatially and temporally. The success rate of ICSI was highly variable in batches of eggs (ranging from 0% to 56%), suggesting that the conditions of eggs are important factors in stabilizing the production of individuals by ICSI. The success in medaka ICSI provides a basis for future research to understand the basic mechanisms in gamete biology of teleosts as well as for development of new technology that can yield valuable applications in fisheries science.

  13. Establishment and characterization of Roberts syndrome and SC phocomelia model medaka (Oryzias latipes).

    Morita, Akihiro; Nakahira, Kumiko; Hasegawa, Taeko; Uchida, Kaoru; Taniguchi, Yoshihito; Takeda, Shunichi; Toyoda, Atsushi; Sakaki, Yoshiyuki; Shimada, Atsuko; Takeda, Hiroyuki; Yanagihara, Itaru

    2012-06-01

    Roberts syndrome and SC phocomelia (RBS/SC) are genetic autosomal recessive syndromes caused by establishment of cohesion 1 homolog 2 ( ESCO 2) mutation. RBS/SC appear to have a variety of clinical features, even with the same mutation of the ESCO2 gene. Here, we established and genetically characterized a medaka model of RBS/SC by reverse genetics. The RBS/SC model was screened from a mutant medaka library produced by the Targeting Induced Local Lesions in Genomes method. The medaka mutant carrying the homozygous mutation at R80S in the conserved region of ESCO2 exhibited clinical variety (i.e. developmental arrest with craniofacial and chromosomal abnormalities and embryonic lethality) as characterized in RBS/SC. Moreover, widespread apoptosis and downregulation of some gene expression, including notch1a, were detected in the R80S mutant. The R80S mutant is the animal model for RBS/SC and a valuable resource that provides the opportunity to extend knowledge of ESCO2. Downregulation of some gene expression in the R80S mutant is an important clue explaining non-correlation between genotype and phenotype in RBS/SC. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  14. The Japanese Medakafish (Oryzias latipes) as Animal Model for Space-related Bone Research

    Renn, J.; Schaedel, M.; Elmasri, H.; Wagner, T.; Goerlich, R.; Furutani-Seiki, M.; Kondoh, H.; Schartl, M.; Winkler, C.

    Long-term space flight leads to bone loss due to reduced mechanical load. Animal models are needed to support the analysis of the underlying mechanisms at the molecular and cellular level that are presently largely unclear. For this, small laboratory fish offer many experimental advantages as in vivo models to study disease related processes. They produce large numbers of completely transparent embryos, are easy to keep under laboratory and space conditions and have relatively compact genomes. We are using the Japanese Medaka to characterize the genetic networks regulating bone formation and to study bone formation and remodeling under microgravity. We showed that despite the large evolutionary distance many known factors regulating bone formation are conserved between fish and humans. This includes osteoprotegerin (opg), a key regulator of bone resorption that is altered at the transcriptional level by simulated microgravity in mammals in vitro (Kanematsu et al., Bone 30, 2002). To monitor, how opg is regulated by altered gravity in vivo in fish and how fish react to microgravity, we isolated the Medaka opg regulatory region and produced transgenic fish that carry the green fluorescent protein reporter under the control of the Medaka opg promoter. This model will be useful to monitor gravity-induced changes at the molecular level in vivo. Fish also provide the opportunity to identify novel genes involved in bone formation by using large-scale mutagenesis screens. We have characterized several lines of mutant fish subjected to ENU mutagenesis that show morphological defects in the formation of the bone precursor cell compartment of the axial skeleton, the sclerotome. Using this genetic approach, the identification of the mutated genes is expected to reveal novel components of the genetic cascades that regulate bone formation. In an attempt to identify genes specifically expressed in the sclerotome in Medaka, we identified and characterized dmrt2, a gene that so far was not known to be involved in bone formation in mammals. Taken together, the Medaka offers excellent experimental approaches to isolate novel bone genes and to analyze the effects of altered gravity on the expression of skeletal factors in a whole-animal model system, with relevance to human diseases. Acknowledgement: This work is supported by the German Aerospace Center (DLR) (50 WB 0152) and the European Space Agency (AO-LS-99-MAP-LSS-003).

  15. Chronic Mycobacterium marinum Infection Acts as a Tumor Promoter in Japanese Medaka (Oryzias latipes)

    An accumulating body of research indicates there is an increased cancer risk associated with chronic infections. The genus Mycobacterium contains a number of species, including M tuberculosis, which mount chronic infections and have been implicated in higher cancer risk. Several ...

  16. Trichioroethylene and Chioral Hydrate Metabolism in the Japanese Medaka Minnow (Oryzias Latipes) In Vitro

    Lipscomb, John

    1996-01-01

    ...: the species is small enough to be reared in large numbers under relatively simple environmental conditions, the gestation period is short so that many generations can be tested in a short period...

  17. Targeted Inactivation of DNA Photolyase Genes in Medaka Fish (Oryzias latipes).

    Ishikawa-Fujiwara, Tomoko; Shiraishi, Eri; Fujikawa, Yoshihiro; Mori, Toshio; Tsujimura, Tohru; Todo, Takeshi

    2017-01-01

    Proteins of the cryptochrome/photolyase family (CPF) exhibit sequence and structural conservation, but their functions are divergent. Photolyase is a DNA repair enzyme that catalyzes the light-dependent repair of ultraviolet (UV)-induced photoproducts, whereas cryptochrome acts as a photoreceptor or circadian clock protein. Two types of DNA photolyase exist: CPD photolyase, which repairs cyclobutane pyrimidine dimers (CPDs), and 6-4 photolyase, which repairs 6-4 pyrimidine-pyrimidone photoproducts (6-4PPs). Although the Cry-DASH protein is classified as a cryptochrome, it also has light-dependent DNA repair activity. To determine the significance of the three light-dependent repair enzymes in recovering from solar UV-induced DNA damage at the organismal level, we generated mutants in each gene in medaka using the CRISPR genome editing technique. The light-dependent repair activity of the mutants was examined in vitro in cultured cells and in vivo in skin tissue. Light-dependent repair of CPD was lost in the CPD photolyase-deficient mutant, whereas weak repair activity against 6-4PPs persisted in the 6-4 photolyase-deficient mutant. These results suggest the existence of a heretofore unknown 6-4PP repair pathway and thus improve our understanding of the mechanisms of defense against solar UV in vertebrates. © 2016 The Authors. Photochemistry and Photobiology published by Wiley Periodicals, Inc. on behalf of American Society for Photobiology.

  18. Bioconcentration and distribution of silver nanoparticles in Japanese medaka (Oryzias latipes)

    Jung, Youn-Joo [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, Ki-Tae [Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of); Kim, Jun. Y. [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of); Yang, Song-Yi; Lee, Byeong-Gweon [Department of Oceanography, Chonnam National University, Gwangju 500-755 (Korea, Republic of); Kim, Sang D., E-mail: sdkim@gist.ac.kr [Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheom-dan Gwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2014-02-01

    Highlights: • The bioconcentration and biodistribution of AgNPs were measured by the silver isotope {sup 110m}Ag. • BCF values were 39.8 ± 7.4, 42.5 ± 5.1 and 116.4 ± 6.1 L kg{sup −1} for AgNPs-CIT, AgNPs-PVP and AgNO{sub 3}, respectively. • The extent of silver ion release from AgNPs affected the uptake kinetic pattern. • AgNPs were mainly concentrated in the liver of Japanese medaka. - Abstract: The study of the bioconcentration of silver nanoparticles (AgNPs) is important to fully understand their hazard potential in the aquatic environment. We synthesized AgNPs radiolabeled with silver isotopes ({sup 110m}Ag) to quantify the bioconcentration of AgNPs coated with citrate (AgNPs-CIT) and polyvinylpyrrolidone (AgNPs-PVP) in Japanese medaka, and to investigate the biodistribution of silver in organs, which were compared with {sup 110m}AgNO{sub 3}. BCF values were determined to be 39.8 ± 7.4, 42.5 ± 5.1 and 116.4 ± 6.1 L kg{sup −1} for AgNPs-CIT, AgNPs-PVP and AgNO{sub 3}, respectively. The release of more silver ions in AgNPs-PVP contributed to a different kinetic uptake pattern with AgNPs-CIT, which was similar to that of AgNO{sub 3}. Bioconcentrated AgNPs in medaka were not observed to be eliminated, independent of surface coating differences, similarly to AgNO{sub 3}. There was no difference in biodistribution in each organ before and after depuration in two types of AgNPs and AgNO{sub 3}, all of which were mainly concentrated in the liver. This study quantified the bioconcentration and distribution of AgNPs and AgNO{sub 3} more precisely by utilizing a silver isotope, which is helpful in monitoring the toxicity of AgNPs to Japanese medaka.

  19. Effects of dietary 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47) exposure on medaka (Oryzias latipes) swimming behavior.

    Sastre, Salvador; Fernández Torija, Carlos; Carbonell, Gregoria; Rodríguez Martín, José Antonio; Beltrán, Eulalia María; González-Doncel, Miguel

    2018-02-01

    A diet fortified with 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47: 0, 10, 100, and 1000 ng/g) was dosed to 4-7-day-old post-hatch medaka fish for 40 days to evaluate the effects on the swimming activity of fish using a miniaturized swimming flume. Chlorpyrifos (CF)-exposed fish were selected as the positive control to assess the validity and sensitivity of the behavioral findings. After 20 and 40 days of exposure, the locomotor activity was analyzed for 6 min in a flume section (arena). The CF positive control for each time point were fish exposed to 50 ng CF/ml for 48 h. Swimming patterns, presented as two-dimensional heat maps of fish movement and positioning, were obtained by geostatistical analyses. The heat maps of the control groups at time point 20 revealed visually comparable swimming patterns to those of the BDE-47-treated groups. For the comparative fish positioning analysis, both the arenas were divided into 15 proportional areas. No statistical differences were found between residence times in the areas from the control groups and those from the BDE-47-treated groups. At time point 40, the heat map overall patterns of the control groups differed visually from that of the 100-ng BDE-47/g-treated group, but a comparative analysis of the residence times in the corresponding 15 areas did not reveal consistent differences. The relative distances traveled by the control and treated groups at time points 20 and 40 were also comparable. The heat maps of CF-treated fish at both time points showed contrasting swim patterns with respect to those of the controls. These differential patterns were statistically supported with differences in the residence times for different areas. The relative distances traveled by the CF-treated fish were also significantly shorter. These results confirm the validity of the experimental design and indicate that a dietary BDE-47 exposure does not affect forced swimming in medaka at growing stages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Aquaporin expression in the Japanese medaka (Oryzias latipes) in freshwater and seawater: challenging the paradigm of intestinal water transport?

    Madsen, Steffen; Bujak, Joanna; Tipsmark, Christian

    2014-01-01

    response to salinity, suggesting that water transport is not regulated at this level. In contrast, mRNA of the Na+,K+,2Cl–-cotransporter type-2 strongly increased in the intestine in SW compared with FW fish. Using custom-made antibodies, Aqp1a, Aqp8ab and Aqp10a were localized in the apical region...... in the intestine of SW fish is surprising, and challenges the paradigm for transepithelial intestinal water absorption in SW fishes....

  1. Evaluation of the carcinogenic, reproductive, and developmental effects of mixtures of contaminants on the Medaka Fish (Oryzias latipes)

    Hartley, W.; Roy, C.

    1993-01-01

    This paper details the initial results of a study to evaluate the effects of mixtures. The study, when completed, will include cadmium in combination with other chemicals. The primary mechanism of cadmium toxicity in adult fishes is gill tissue necrosis, but this was observed at very high laboratory concentrations or special circumstances. There is a lack of aquatic toxicological research involving specific developmental effects of cadmium in the medaka embryo. There is a need to investigate the sublethal effects of cadmium in low concentration where mortality of the exposed biological organism is not the endpoint of toxicity. The toxicity of cadmium for embryonic, juvenile, and adult fish is variable according to species and stage of life. The object of the following experiments was to observe the various physiological, morphological, and limited behavioral effects of cadmium on the medaka embryo

  2. DNA methyltransferase expressions in Japanese rice fish (Oryzias latipes) embryogenesis is developmentally regulated and modulated by ethanol and 5-azacytidine

    We aimed to investigate the impact of the epigenome in inducting fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish embryogenesis. One of the significant events in epigenome is DNA methylation which is catalyzed by DNA methyl transferase (DNMT) enzymes. We analyzed DNMT enzyme m...

  3. Modulation of DNA methylation machineries in japanese rice fish (Oryzias latipes) embryogenesis by ethanol and 5-azacytidine

    As a sequel of our investigations on the impact of epigenome in inducing fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish, we investigated on several DNA methylation machinery genes including DNA methyl transferase 3ba (dnmt3ba) and methyl binding proteins (MBPs), namely, mbdl...

  4. In Vivo Anti-estrogenic Effects of Menadione on Hepatic Estrogen-responsive Gene Expression in Male Medaka (Oryzias latipes)

    Yamaguchi, Akemi; Kohra, Shinya; Ishibashi, Hiroshi; Arizono, Koji; Tominaga, Nobuaki

    2008-01-01

    Menadione, a synthetic vitamin K3, exhibits anti-estrogenic activity on in vitro assay. However, the in vivo anti-estrogenic effects of menadione have not been determined, while correlations between biological effects and structural changes are unclear. Thus, we investigated the in vivo anti-estrogenic activity of menadione under fluorescent light and dark conditions. Suppression of the hepatic estrogen response genes vitellogenin1 (VTG1), VTG2 and estrogen receptor-α (ER-α) was used as an in...

  5. PROMOTION BY 17BETA-ESTRADIOL AND BETA-HEXACHLOROCYCLOHEXANE OF HEPATOCELLULAR TUMORS IN MEDAKA, ORYZIAS LATIPES. (R825298)

    AbstractA feature common to many laboratory and field studies with various fish species is a higher prevalence of hepatocellular neoplasia in females than in males. During female sexual maturation, endogenous estrogens stimulate substantial increases in synthetic acti...

  6. EFFECTS OF O,P'-DDT ON GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES). (R827098)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  7. Development of an Aquatic Bioassay using the Medaka (Oryzias latipes) to Assess Human Health Risk: Tumor Immunodiagnosis.

    1995-01-10

    tumors, melanoma Actin Skeletal muscle Chromogranin Neuroendocrine cells Myelin associated protein Neurons ULEX europaeus agglutinin I Endothelial...Actin BioGenex + Ulex europaeus agglutinin I Vector Endothelial cell antigen BioGenex ND Lysozyme BioGenex ND S-100 protein BioGenex + MAP-2

  8. In ovo exposure to o,p -DDE affects sexual development but not sexual differentiation in Japanese medaka (Oryzias latipes).

    Papoulias, D.M.; Villalobos, Sergio A.; Meadows, J.; Noltie, Douglas B.; Giesy, J.P.; Tillitt, D.E.

    2003-01-01

    Despite being banned in many countries, dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) continue to be found in fish tissues at concentrations of concern. Like o,p -DDT, o,p -DDE is estrogenic and is believed to exert its effects through binding to the estrogen receptor. The limited toxicologic data for o,p -DDE suggest that it decreases fecundity and fertility of fishes. We conducted an egg injection study using the d-rR strain of medaka and environmentally relevant concentrations of o,p -DDE to examine its effects on sexual differentiation and development. The gonads of exposed fish showed no evidence of sex reversal or intersex. However, other gonad abnormalities occurred in exposed individuals. Females exhibited few vitellogenic oocytes and increased atresia. Male testes appeared morphologically normal but were very small. Gonadosomatic index values for both sexes were lower for exposed fish. Our observations of abnormal female and very small male gonads after in ovo o,p -DDE exposure may be indicative of effects on early endocrine processes important for normal ovarian and testicular development.

  9. Modulation of DNA methylation machineries in Japanese rice fish (Oryzias latipes) embryogenesis by ethanol and 5-azacytidine.

    Dasmahapatra, Asok K; Khan, Ikhlas A

    2016-01-01

    As a sequel of our investigations on the impact of epigenome in inducing fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish, we have investigated on several DNA methylation machinery genes including DNA methyl transferase 3ba (dnmt3ba) and methyl binding proteins (MBPs), namely, mbd1b, mbd3a, mbd3b, and mecp2 at the transcription level. Studies were made during normal development, from 0day post fertilization (dpf) to hatching, and also exposing the fertilized eggs to ethanol or a DNMT inhibitor, 5-azacytidine (5-azaC). We observed that during development, all these genes followed distinct expression patterns, generally high mRNA copies in early phases (0-1dpf) and significantly low mRNA copies prior to or after hatching. Ethanol (100-500mM, 0-2dpf) was unable to alter any of these mRNAs in 2dpf; additional four day (2-6dpf) maintenance of these embryos in ethanol-free environment, on 6dpf, was also unable to establish any significant difference in these mRNA levels in comparison with the corresponding controls. However, continuous exposure of fertilized eggs in 300mM ethanol, 0-6dpf, showed significantly high mRNA copies only in MBPs (mbd1b, mbd3a, mbd3b, mecp2). 5-azaC (2mM) on 2dpf was able to enhance only mbd3b mRNA. Removal of 5-azaC and maintenance of these embryos in clean medium, 2-6dpf, showed significantly enhanced mbd3b and mecp2 mRNAs compared to corresponding controls on 6dpf. Our studies showed that in Japanese rice fish embryogenesis both ethanol and 5-azaC have the potential to specifically modulate the developmental rhythm of DNA methylation machineries. Published by Elsevier Inc.

  10. Transgenerational effects from early developmental exposures to bisphenol A or 17α-ethinylestradiol in medaka, Oryzias latipes

    Bhandari, Ramji K.; vom Saal, Frederick S.; Tillitt, Donald E.

    2015-01-01

    The transgenerational consequences of environmental contaminant exposures of aquatic vertebrates have the potential for broad ecological impacts, yet are largely uninvestigated. Bisphenol A (BPA) and 17α-ethinylestradiol (EE2) are two ubiquitous estrogenic chemicals present in aquatic environments throughout the United States and many other countries. Aquatic organisms, including fish, are exposed to varying concentrations of these chemicals at various stages of their life history. Here, we tested the ability of embryonic exposure to BPA or EE2 to cause adverse health outcomes at later life stages and transgenerational abnormalities in medaka fish. Exposures of F0 medaka to either BPA (100 μg/L) or EE2 (0.05 μg/L) during the first 7 days of embryonic development, when germ cells are differentiating, did not cause any apparent phenotypic abnormalities in F0 or F1 generations, but led to a significant reduction in the fertilization rate in offspring two generations later (F2) as well as a reduction of embryo survival in offspring three generations later (F3). Our present observations suggest that BPA or EE2 exposure during development induces transgenerational phenotypes of reproductive impairment and compromised embryonic survival in fish of subsequent generations. These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments.

  11. Embryonic exposure of medaka (Oryzias latipes) to propylparaben: Effects on early development and post-hatching growth

    González-Doncel, Miguel; García-Mauriño, José Enrique; San Segundo, Laura; Beltrán, Eulalia M.; Sastre, Salvador; Fernández Torija, Carlos

    2014-01-01

    Here we proposed a battery of non-invasive biomarkers and a histological survey to examine physiological/anatomical features in embryos, eleutheroembryos (13 days post-fertilization, dpf), and larvae (28–42 dpf) of medaka to investigate the effects of embryonic exposure to propylparaben (PrP). Concentrations <1000 μg PrP/L didn't exert early or late toxic effects. However, survivorship was affected at 4000 μg/L in eleutheroembryos and at ≥1000 μg/L in larvae. Histological alterations were found in 37.5% of eleutheroembryos exposed to 4000 μg PrP/L. Morphometric analysis of the gallbladder revealed significant dilation at ≥400 μg/L throughout embryo development. Ethoxyresorufin-O-deethylase (EROD), as indicator of cytochrome P4501A activity, didn't reveal induction/inhibition although its combination with a P4501A agonist (i.e. β-naphthoflavone) resulted in a synergic EROD response. Results suggest a low toxicity of PrP for fish and support the use of fish embryos and eleutheroembryos as alternatives of in vivo biomarkers indicative of exposure/toxicity. -- Highlights: • Addressing pre- and post-hatch effects from medaka embryo exposure to propylparaben. • Macroscopical effects (length, mortality) seen primarily after hatch at ≥400 μg/L. • Synergic EROD embryonic response when propylparaben combined with a CYP1A agonist. • Significant gallbladder dilation seen at ≥400 μg PrP/L and as soon as discernible. • Histological harm to eleutheroembryos in peritoneal cavity, liver, kidney and brain. -- PrP resulted in low toxicity based on non-invasive biomarkers and histological tools to analyze pre- and post-hatch effects after medaka embryo exposure

  12. Expression Profiles of Branchial FXYD Proteins in the Brackish Medaka Oryzias dancena: A Potential Saltwater Fish Model for Studies of Osmoregulation

    Yang, Wen-Kai; Kang, Chao-Kai; Chang, Chia-Hao; Hsu, An-Di; Lee, Tsung-Han; Hwang, Pung-Pung

    2013-01-01

    FXYD proteins are novel regulators of Na+-K+-ATPase (NKA). In fish subjected to salinity challenges, NKA activity in osmoregulatory organs (e.g., gills) is a primary driving force for the many ion transport systems that act in concert to maintain a stable internal environment. Although teleostean FXYD proteins have been identified and investigated, previous studies focused on only a limited group of species. The purposes of the present study were to establish the brackish medaka (Oryzias dancena) as a potential saltwater fish model for osmoregulatory studies and to investigate the diversity of teleostean FXYD expression profiles by comparing two closely related euryhaline model teleosts, brackish medaka and Japanese medaka (O. latipes), upon exposure to salinity changes. Seven members of the FXYD protein family were identified in each medaka species, and the expression of most branchial fxyd genes was salinity-dependent. Among the cloned genes, fxyd11 was expressed specifically in the gills and at a significantly higher level than the other fxyd genes. In the brackish medaka, branchial fxyd11 expression was localized to the NKA-immunoreactive cells in gill epithelia. Furthermore, the FXYD11 protein interacted with the NKA α-subunit and was expressed at a higher level in freshwater-acclimated individuals relative to fish in other salinity groups. The protein sequences and tissue distributions of the FXYD proteins were very similar between the two medaka species, but different expression profiles were observed upon salinity challenge for most branchial fxyd genes. Salinity changes produced different effects on the FXYD11 and NKA α-subunit expression patterns in the gills of the brackish medaka. To our knowledge, this report is the first to focus on FXYD expression in the gills of closely related euryhaline teleosts. Given the advantages conferred by the well-developed Japanese medaka system, we propose the brackish medaka as a saltwater fish model for

  13. IDENTIFICATION AND CHARACTERIZATION OF CDNA ENCODING CYTOCHROME P450 3A FROM THE FRESH WATER TELEOST MEDAKA (ORYZIAS LATIPES). (R825298)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. EXPRESSION OF BRANCHIAL FLAVIN-CONTAINING MONOOXYGENASE IS DIRECTLY CORRELATED WITH SALINITY-INDUCED ALDICARB TOXICITY IN THE EURYHALINE FISH (ORYZIAS LATIPES). (R826109)

    AbstractEarlier studies in our laboratory have demonstrated a reduction of flavin-containing monooxygenase (FMO) activity when salt-water adapted euryhaline fish were transferred to water of less salinity. Since FMOs have been shown to be responsible for the bioact...

  15. Comparison of TiO2 nanoparticle and graphene-TiO2 nanoparticle composite phototoxicity to Daphnia magna and Oryzias latipes

    With a dramatic rise in complexity, needs of nanotoxicology research go beyond simple forms of nanomaterials. This study compared the phototoxicity of nano-TiO2and graphene-TiO2 nanocomposite (GNP). GNP was synthesized based on a hydrothermal method, which simultaneously performe...

  16. TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS. (R827098)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  17. TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS

    17a-Ethinylestradiol (EE), a synthetic estrogen found in birth control pills, has been detected in the effluent of municipal wastewater treatment plants in several countries. Because EE was designed to be extremely potent at the estrogen receptor (ER), environmental exposure to l...

  18. CORRELATION OF FLAVIN-CONTAINING MONOOXYGENASE ACTIVITY, ALDICARB TOXICITY AND SALINITY IN THE EURYHALINE FISH, JAPANESE MEDAKA (ORYZIAS LATIPES). (R826109)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. Detection of γ-ray-induced DNA damages in malformed dominant lethal embryos of the Japanese medaka (Oryzias latipes) using AP-PCR fingerprinting

    Kubota, Yoshiko; Shimada, Atsuko; Shima, Akihiro

    1992-01-01

    Adult male fish of the medaka HNI strain exposed to 9.5 Gy or 19 Gy (0.95 Gy/min) of γ-rays were mated with non-irradiated female fish of the Hd-rR strain. Genomic DNA was prepared from malformed individual embryos which were expected to be dominant lethal and used for AP-PCR fingerprinting. By the use of a part of the T3 promoter sequence (20 mer), which is not found in the medaka genome as an arbitrary primer, polymorphisms were found in genomic fingerprints which could distinguish the parental strains. On the other hand, fingerprints of F1 hybrids were found to be the sum of those of their parents. Based on these findings, the fingerprints of genomic DNA of each severely malformed embryo were analyzed, because it was expected that radiation-induced genomic damages resulting in severe malformation and eventually in dominant lethals should be detected as changes in paternal fingerprints of F1 hybrids. Indeed, changes were found in genomic DNA as loss of some paternal bands in fingerprints of malformed embryos. One of 10 malformed embryos obtained from 9.5 Gy γ-irradiated males had lost 5 bands. These results indicated a possibility that quantitative as well as qualitative estimation of γ-ray-induced DNA damages can be made by this method which does not require the functional selection based on a specific target gene. (author). 16 refs., 3 figs., 1 tab

  20. PROMOTION BY 17&BETA;-ESTRADIOL AND &BETA;-HEXACHLOROCYCLOHEXANE OF HEPATOCELLULAR TUMORS IN MEDAKA, ORYZIAS LATIPES. AQUAT. (R828676C002)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. Photorepair and excision repair removal of UV-induced pyrimidine dimers and (6-4) photoproducts in the tail fin of the Medaka, Oryzias latipes

    Funayama, Tomoo; Mitani, Hiroshi; Shima, Akihiro; Ishigaki, Yasuhito; Matsunaga, Tsukasa; Nikaido, Osamu.

    1994-01-01

    Induction and repair of UV-B induced DNA damage in the tail fin of the Medaka, were examined immunohistochemically and by the enzyme-linked immunosorbent assay (ELISA). UV-induced DNA damage was detected only in the outermost layer of epithelial cells and did not differ in fishes having different degree of melanization. Both pyrimidine dimers and (6-4) photoproducts in the fin cells were removed by excision repair in the dark, the excision of (6-4) photoproducts being about twice as efficient as that of pyrimidine dimers. The rate of excision repair of UV-induced lesions in fin tissue was three to four times that in cultured Medaka cells, OL32.. In the fin cells, reductions in the numbers of pyrimidine dimers and (6-4) photoproducts were seen after treatment with fluorescent light, whereas less reductions of pyrimidine dimers and no reductions of (6-4) photoproducts were observed in OL32 cells. (author)

  2. Effects of kisspeptin1 on electrical activity of an extrahypothalamic population of gonadotropin-releasing hormone neurons in medaka (Oryzias latipes).

    Zhao, Yali; Wayne, Nancy L

    2012-01-01

    Kisspeptin (product of the kiss1 gene) is the most potent known activator of the hypothalamo-pituitary-gonadal axis. Both kiss1 and the kisspeptin receptor are highly expressed in the hypothalamus of vertebrates, and low doses of kisspeptin have a robust and long-lasting stimulatory effect on the rate of action potential firing of hypophysiotropic gonadotropin releasing hormone-1 (GnRH1) neurons in mice. Fish have multiple populations of GnRH neurons distinguished by their location in the brain and the GnRH gene that they express. GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb are neuromodulatory and do not play a direct role in regulating pituitary-gonadal function. In medaka fish, the electrical activity of TN-GnRH3 neurons is modulated by visual cues from conspecifics, and is thought to act as a transmitter of information from the external environment to the central nervous system. TN-GnRH3 neurons also play a role in sexual motivation and arousal states, making them an important population of neurons to study for understanding coordination of complex behaviors. We investigated the role of kisspeptin in regulating electrical activity of TN-GnRH3 neurons in adult medaka. Using electrophysiology in an intact brain preparation, we show that a relatively brief treatment with 100 nM of kisspeptin had a long-lasting stimulatory effect on the electrical activity of an extrahypothalamic population of GnRH neurons. Dose-response analysis suggests a relatively narrow activational range of this neuropeptide. Further, blocking action potential firing with tetrodotoxin and blocking synaptic transmission with a low Ca(2+)/high Mg(2+) solution inhibited the stimulatory action of kisspeptin on electrical activity, indicating that kisspeptin is acting indirectly through synaptic regulation to excite TN-GnRH3 neurons. Our findings provide a new perspective on kisspeptin's broader functions within the central nervous system, through its regulation of an extrahypothalamic population of GnRH neurons involved in multiple neuromodulatory functions.

  3. Establishment of estrogen receptor 1 (ESR1)-knockout medaka: ESR1 is dispensable for sexual development and reproduction in medaka, Oryzias latipes.

    Tohyama, Saki; Ogino, Yukiko; Lange, Anke; Myosho, Taijun; Kobayashi, Tohru; Hirano, Yu; Yamada, Gen; Sato, Tomomi; Tatarazako, Norihisa; Tyler, Charles R; Iguchi, Taisen; Miyagawa, Shinichi

    2017-08-01

    Estrogens play fundamental roles in regulating reproductive activities and they act through estrogen receptor (ESR) in all vertebrates. Most vertebrates have two ESR subtypes (ESR1 and ESR2), whereas teleost fish have at least three (Esr1, Esr2a and Esr2b). Intricate functionalization has been suggested among the Esr subtypes, but to date, distinct roles of Esr have been characterized in only a limited number of species. Study of loss-of-function in animal models is a powerful tool for application to understanding vertebrate reproductive biology. In the current study, we established esr1 knockout (KO) medaka using a TALEN approach and examined the effects of Esr1 ablation. Unexpectedly, esr1 KO medaka did not show any significant defects in their gonadal development or in their sexual characteristics. Neither male or female esr1 KO medaka exhibited any significant changes in sexual differentiation or reproductive activity compared with wild type controls. Interestingly, however, estrogen-induced vitellogenin gene expression, an estrogen-responsive biomarker in fish, was limited in the liver of esr1 KO males. Our findings, in contrast to mammals, indicate that Esr1 is dispensable for normal development and reproduction in medaka. We thus provide an evidence for estrogen receptor functionalization between mammals and fish. Our findings will also benefit interpretation of studies into the toxicological effects of estrogenic chemicals in fish. © 2017 Japanese Society of Developmental Biologists.

  4. Polycystic kidney disease in the medaka (Oryzias latipes pc mutant caused by a mutation in the Gli-Similar3 (glis3 gene.

    Hisashi Hashimoto

    Full Text Available Polycystic kidney disease (PKD is a common hereditary disease in humans. Recent studies have shown an increasing number of ciliary genes that are involved in the pathogenesis of PKD. In this study, the Gli-similar3 (glis3 gene was identified as the causal gene of the medaka pc mutant, a model of PKD. In the pc mutant, a transposon was found to be inserted into the fourth intron of the pc/glis3 gene, causing aberrant splicing of the pc/glis3 mRNA and thus a putatively truncated protein with a defective zinc finger domain. pc/glis3 mRNA is expressed in the epithelial cells of the renal tubules and ducts of the pronephros and mesonephros, and also in the pancreas. Antisense oligonucleotide-mediated knockdown of pc/glis3 resulted in cyst formation in the pronephric tubules of medaka fry. Although three other glis family members, glis1a, glis1b and glis2, were found in the medaka genome, none were expressed in the embryonic or larval kidney. In the pc mutant, the urine flow rate in the pronephros was significantly reduced, which was considered to be a direct cause of renal cyst formation. The cilia on the surface of the renal tubular epithelium were significantly shorter in the pc mutant than in wild-type, suggesting that shortened cilia resulted in a decrease in driving force and, in turn, a reduction in urine flow rate. Most importantly, EGFP-tagged pc/glis3 protein localized in primary cilia as well as in the nucleus when expressed in mouse renal epithelial cells, indicating a strong connection between pc/glis3 and ciliary function. Unlike human patients with GLIS3 mutations, the medaka pc mutant shows none of the symptoms of a pancreatic phenotype, such as impaired insulin expression and/or diabetes, suggesting that the pc mutant may be suitable for use as a kidney-specific model for human GLIS3 patients.

  5. A new data-mining method to search for behavioral properties that induce alignment and their involvement in social learning in medaka fish (Oryzias latipes.

    Takashi Ochiai

    Full Text Available BACKGROUND: Coordinated movement in social animal groups via social learning facilitates foraging activity. Few studies have examined the behavioral cause-and-effect between group members that mediates this social learning. METHODOLOGY/PRINCIPAL FINDINGS: We first established a behavioral paradigm for visual food learning using medaka fish and demonstrated that a single fish can learn to associate a visual cue with a food reward. Grouped medaka fish (6 fish learn to respond to the visual cue more rapidly than a single fish, indicating that medaka fish undergo social learning. We then established a data-mining method based on Kullback-Leibler divergence (KLD to search for candidate behaviors that induce alignment and found that high-speed movement of a focal fish tended to induce alignment of the other members locally and transiently under free-swimming conditions without presentation of a visual cue. The high-speed movement of the informed and trained fish during visual cue presentation appeared to facilitate the alignment of naïve fish in response to some visual cues, thereby mediating social learning. Compared with naïve fish, the informed fish had a higher tendency to induce alignment of other naïve fish under free-swimming conditions without visual cue presentation, suggesting the involvement of individual recognition in social learning. CONCLUSIONS/SIGNIFICANCE: Behavioral cause-and-effect studies of the high-speed movement between fish group members will contribute to our understanding of the dynamics of social behaviors. The data-mining method used in the present study is a powerful method to search for candidates factors associated with inter-individual interactions using a dataset for time-series coordinate data of individuals.

  6. Gender-related effects of 17-{beta}-estradiol and B-hexachlorocyclohexane on liver tumor formation in medaka (Oryzias latipes)

    Cooke, J.B.; Hinton, D.E. [Univ. of California, Davis, CA (United States)

    1994-12-31

    When medaka were acutely exposed to diethylnitrosamine (DEN), greater incidence of hepatocarcinoma was seen in female versus male fish. This is possibly related to elevated female endogenous estrogens, which increase liver weight and production of vitellogenin. To examine roles of estrogens in tumor modulation, 21-day old medaka were exposed to DEN (200 ppm for 24 hr.), then fed purified diets containing the estrogenic compound {beta}-hexachlorocyclohexane ({beta}-HCH) or 17-{beta}estradiol (E2) for 6 months. Incidences of basophilic preneoplastic foci of cellular alteration in females receiving DEN and 0.01, 0.1, or 1.0 ppm E2 were three times the incidences in similarly-treated males. Also, incidences of basophilic foci in DEN + 0.1 ppm E2 males were significantly increased over DEN-only males and were equal to incidences in DEN-only females. Liver weights and hepatosomatic indices of males given 0.1 ppm E2 were not significantly different than females fed control diet. Females fed 0.01-10.0 ppm {beta}-HCH after DEN had 4--5 times greater incidences of basophilic foci as males. Gender-related effects on kinetics of growth rates and volumes of foci are being examined.

  7. CYTOCHROME P450 1A1 AND STRESS PROTEIN INDUCTION IN EARLY LIFE STAGES OF MEDAKA (ORYZIAS LATIPES) EXPOSED TO TRICHLOROETHYLENE (TCE) SOOT AND DIFFERENT FRACTIONS. (R825433)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  8. Aerial release of Rhinoncomimus latipes (Coleoptera: Curculionidae) to control Persicaria perfoliata (Polygonaceae) using an unmanned aerial system.

    Park, Yong-Lak; Gururajan, Srikanth; Thistle, Harold; Chandran, Rakesh; Reardon, Richard

    2018-01-01

    Rhinoncomimus latipes (Coleoptera: Curculionidae) is a major biological control agent against the invasive plant Persicaria perfoliata. Release of R. latipes is challenging with the current visit-and-hand release approach because P. perfoliata shows a high degree of patchiness in the landscape, possesses recurved barbs on its stems, and often spreads into hard-to-access areas. This 3-year study developed and evaluated unmanned aerial systems (UAS) for precise aerial release of R. latipes to control P. perfoliata. We have developed two UAS (i.e. quad-rotor and tri-rotor) and an aerial release system to disseminate R. latipes. These include pods containing R. latipes and a dispenser to accommodate eight pods. Results of field tests to evaluate the systems showed no significant (P > 0.05) effects on survivorship and feeding ability of R. latipes after aerial release. Our study demonstrates the potential of UAS for precision aerial release of biological control agents to control invasive plants. The aerial deployment systems we have developed, including both pods and a dispenser, are low cost, logistically practical, and effective with no negative effects on aerially released R. latipes. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Preferential edge habitat colonization by a specialist weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae)

    J.A. Hough-Goldstein; E. Lake; V. D' Amico; S.H. Berg

    2012-01-01

    Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological control agent of mile-a-minute weed, ...

  10. Preferential Edge Habitat Colonization by a Specialist Weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae)

    Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological...

  11. Preliminary Study on Testicular Germ Cell Transplantation of Endemic Species Oryzias celebensis

    Andriani, I.; Agustiani, F.; Hassan, M.; Parenrengi, A.; Inoue, K.

    2018-03-01

    The research has been conducted to study some technical steps for male germ-plasm from endemic fish species such as some species of Oryzias fish in Indonesia to preserve and propagate through germ cell transplantation technology. For preliminary research, the study was started with germ cell characterization of testes, cryopreservation of TGC and the transplantation of Oryzias celebensis as candidates for surrogate broodstock of Oryzias fish male germ plasm. The data analized included the potential number of TGC as donor, the viability of cryopreserved TGC in two types of cryoprotectans and the survival rate of O.celebensis larvae as recipient after transplantation. The result showed that the average amount of TGC yielded after dissociation was 131000 ± 31349 with 74.2 % viability of TGC each. Cryoprotectan10% DMSO +glucose yielded higher viable of TGC. More than 80 % of O.celebensis larvae survived after transplantation. In conclusion, these preliminary data of O.celebensis as surrogate broodstock candidate will support the application of TGC transplantation technology in Oryzias endemic species.

  12. Desert springs: deep phylogeographic structure in an ancient endemic crustacean (Phreatomerus latipes.

    Michelle T Guzik

    Full Text Available Desert mound springs of the Great Artesian Basin in central Australia maintain an endemic fauna that have historically been considered ubiquitous throughout all of the springs. Recent studies, however, have shown that several endemic invertebrate species are genetically highly structured and contain previously unrecognised species, suggesting that individuals may be geographically 'stranded in desert islands'. Here we further tested the generality of this hypothesis by conducting genetic analyses of the obligate aquatic phreatoicid isopod Phreatomerus latipes. Phylogenetic and phylogeographic relationships amongst P. latipes individuals were examined using a multilocus approach comprising allozymes and mtDNA sequence data. From the Lake Eyre region in South Australia we collected data for 476 individuals from 69 springs for the mtDNA gene COI; in addition, allozyme electrophoresis was conducted on 331 individuals from 19 sites for 25 putative loci. Phylogenetic and population genetic analyses showed three major clades in both allozyme and mtDNA data, with a further nine mtDNA sub-clades, largely supported by the allozymes. Generally, each of these sub-clades was concordant with a traditional geographic grouping known as spring complexes. We observed a coalescent time between ∼2-15 million years ago for haplotypes within each of the nine mtDNA sub-clades, whilst an older total time to coalescence (>15 mya was observed for the three major clades. Overall we observed that multiple layers of phylogeographic history are exemplified by Phreatomerus, suggesting that major climate events and their impact on the landscape have shaped the observed high levels of diversity and endemism. Our results show that this genus reflects a diverse fauna that existed during the early Miocene and appears to have been regionally restricted. Subsequent aridification events have led to substantial contraction of the original habitat, possibly over repeated Pleistocene

  13. Thyroidal angiogenesis in zebrafish ( Danio rerio ) exposed to high ...

    As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not only histopathologically but also ...

  14. A bioenergetic model for zebrafish Danio rerio (Hamilton)

    Chizinski, C.J.; Sharma, Bibek; Pope, K.L.; Patino, R.

    2008-01-01

    A bioenergetics model was developed from observed consumption, respiration and growth rates for zebrafish Danio rerio across a range (18-32?? C) of water temperatures, and evaluated with a 50 day laboratory trial at 28?? C. No significant bias in variable estimates was found during the validation trial; namely, predicted zebrafish mass generally agreed with observed mass. ?? 2008 The Authors.

  15. Thyroidal angiogenesis in zebrafish (Danio rerio) exposed to high ...

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not only.

  16. Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae)

    Assunção-Albuquerque, MJT.; Peso-Aguiar, MC.; Albuquerque, FS.

    2010-01-01

    There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, r...

  17. TERATOLOGIC EFFECTS OF BISPHENOL A ON ZEBRAFISH (Danio rerio

    Cansu Akbulut

    2013-01-01

    Full Text Available Zebrafish (Danio rerio has easy reproductive capacity and transparent embryos and therefore generally preffered for scientific studies as a vertebrate model. Because of bisphenol A is produced too much and used for making plastics, many organisms including human are exposed to this substance. Bisphenol A has estrogenic activity and thus it effects fertility. So, in our study, effects of low doses of bisphenol A (4mg/L and 8 mg/L on embryo and larva development was investigated.

  18. Nitrite toxicity assessment in Danio rerio and Poecilia reticulata

    Petra Doleželová

    2011-01-01

    Full Text Available Nitrite is a natural component of the nitrogen cycle in the environment. Although it usually occurs in low concentrations, elevated concentrations caused by effluents or affected nitrification process can lead to serious health deterioration of fish. Two aquarium fish zebrafish (Danio rerio and guppy (Poecilia reticulata are recommended to use as model organisms in toxicity tests. However, their sensitivity to nitrite can differ. The aim of this study was to define acute toxicity of nitrite by the semistatic method according to OECD No. 203 (Fish, Acute toxicity test. The series of 4 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The 96hLC50 NO2- value for D. rerio and P. reticulata was 242.55 ± 15.79 mg·l-1 and 30.2 ± 8.74 mg·l-1, respectively. We have proved significant difference (p D. rerio and P. reticulata. The results showed different sensitivities to nitrites in tested fish species, which could be related to species-specific branchial chloride uptake mechanism. This is the first study on this fish species.

  19. Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera--Noctuidae).

    Assunção-Albuquerque, M J T; Peso-Aguiar, M C; Albuquerque, F S

    2010-08-01

    There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight) of Paspalum maritimum (Trin) in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

  20. Oryzias melastigma - an effective substitute for exotic larvicidal fishes: enhancement of its reproductive potential by supplementary feeding.

    Dutta, Abir Lal; Dey, Sajal Kumar; Chakraborty, Debargha; Manna, Asim Kumar; Manna, Pankaj Kumar

    2013-12-01

    A preliminary study was conducted on the efficacy of Oryzias melastigma in consuming mosquito larva so as to control mosquito and mosquito borne diseases, and enhancing its reproductive success using supplementary feed. Oryzias melastigma is a larvivore fish and widely distributed in the shallow water, wetlands of Gangetic plains and peninsular India. These studies indicate that O. melastigma is a prolific breeder and gregarious feeder of mosquito larvae. Increased reproduction by providing different supplementary feed, of which Ulothrix acted remarkably, may aid in wide spread use of this fish as a biological control measure against mosquitoes. One adult fish of any sex can consume 87.1% first instars mosquito larvae/day. So, early stages of mosquito larvae are effectively controlled, as compared to other successive stages. Ulothrix has considerable effect on egg production, successful hatching and regaining reproductive maturity of female in surprisingly quicker interval.

  1. Daily shoaling patterns in the zebrafish Danio rerio

    Timothy PACIOREK, Scott McROBERT

    2013-12-01

    Full Text Available Shoaling intensity in zebrafish Danio rerio is believed to vary throughout subjective day and night hours. This experiment examines long term variations in shoaling behavior. Adult zebrafish Danio rerio were maintained under a 12:12 LD cycle (with dim red light serving as reduced visibility during subjective dark hours, and their shoaling behavior was monitored every hours for a three-day period of time. Our results show that zebrafish perform shoaling behavior throughout subjective day and under reduced visibility conditions, although mean shoaling times during the light phase were significantly higher than mean shoaling times during the dark phase. However, on the 3rd day of the experiment, mean shoaling times during the subjective night had increased and mean shoaling times during the subjective day had decreased. This shift in intensity was not seen on the first two days of the study, and may represent the influence of experience on the behavior of the test fish. We believe this study shows that shoaling behavior changes with light/dark cycles and that fish shoal even during reduced visibility conditions [Current Zoology 59 (6:754–760, 2013].

  2. Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982) (Lepidoptera - Noctuidae)

    Albuquerque, M. J. T. Assunção; Aguiar, M. C. Peso; Albuquerque, F. S.

    2010-01-01

    p.459-463 There is much evidence to support that Mocis latipes larvae (Guenèe, 1852) are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. As...

  3. Analysis of Lethality and Malformations During Zebrafish (Danio rerio) Development.

    Raghunath, Azhwar; Perumal, Ekambaram

    2018-01-01

    The versatility offered by zebrafish (Danio rerio) makes it a powerful and an attractive vertebrate model in developmental toxicity and teratogenicity assays. Apart from the newly introduced chemicals as drugs, xenobiotics also induce abnormal developmental abnormalities and congenital malformations in living organisms. Over the recent decades, zebrafish embryo/larva has emerged as a potential tool to test teratogenicity potential of these chemicals. Zebrafish responds to compounds as mammals do as they share similarities in their development, metabolism, physiology, and signaling pathways with that of mammals. The methodology used by the different scientists varies enormously in the zebrafish embryotoxicity test. In this chapter, we present methods to assess lethality and malformations during zebrafish development. We propose two major malformations scoring systems: binomial and relative morphological scoring systems to assess the malformations in zebrafish embryos/larvae. Based on the scoring of the malformations, the test compound can be classified as a teratogen or a nonteratogen and its teratogenic potential is evaluated.

  4. Detection of Metallothionein in Javanese Medaka (Oryzias javanicus, Using a scFv-Immobilized Protein Chip

    Euiyeon Lee

    2018-04-01

    Full Text Available Environmental pollution by various industrial chemicals and biological agents poses serious risks to human health. Especially, marine contamination by potentially toxic elements (PTEs has become a global concern in recent years. Many efforts have been undertaken to monitor the PTE contamination of the aquatic environment. However, there are few approaches available to assess the PTE exposure of aquatic organisms. In this research, we developed a strategy to evaluate the heavy metal exposure of marine organisms, by measuring the expression levels of metallothionein protein derived from Oryzias javanicus (OjaMT. OjaMT is a biomarker of heavy metal exposure because the expression level increases upon heavy metal exposure. The developed assay is based on a real-time, label-free surface plasmon resonance (SPR measurement. Anti-OjaMT antibody and anti-OjaMT single-chain fragment of variable region (scFv were used as detection probes. Two types of SPR sensor chips were fabricated, by immobilizing antibody or Cys3-tagged scFv (scFv-Cys3 in a controlled orientation and were tested for in situ label-free OjaMT detection. Compared to the antibody-presenting sensor chips, the scFv-presenting sensor chips showed improved performance, displaying enhanced sensitivity and enabling semi-quantitative detection. The portable SPR system combined with scFv-immobilized sensor chips is expected to provide an excellent point-of-care testing system that can monitor target biomarkers in real time.

  5. Comparative Toxicity of Different Crude Oils on the Cardiac Function of Marine Medaka (Oryzias melastigma Embryo

    Zhendong Zhang

    2014-12-01

    Full Text Available The acute toxic effect of different crude oils (heavy crude oil and bonny light crude oil on embryos of marine medaka Oryzias melastigma was measured and evaluated by exposure to the water-accommodated fraction (WAF in the present study. The cardiac function of medaka embryos was used as target organ of ecotoxicological effect induced by oil exposure. Results showed that the developing marine medaka heart was a sensitive target organ to crude oil exposure the heavy crude oil WAF was more toxic to cardiac function of medaka embryos than bonny light cured oil one. Cardiac function of medaka embryos was clearly affected by exposure to heavy crude oil WAF after 24 hours exposure and showed a dose-dependent slowing of heart rate. Furthermore, swelled and enlarged heart morphology, lowered blood circulation and accumulation of blood cells around the heart area were found. However, the toxic effect of bonny light crude oil on cardiac function of medaka embryos was comparatively low. Statistical results showed that the cardiac function was only affected by highest bonny light crude oil WAF (9.8 mg/L exposure treatment. These findings indicated that cardiac function of marine medaka embryo was a good toxicity model for oil pollution and could be used to compare and evaluate the toxicity of different crude oils. The heart rate was an appropriate endpoint in the acute toxicity test.

  6. Using energy budget data to assess the most damaging life-stage of an agricultural pest Mocis latipes (Guenèe, 1982 (Lepidoptera - Noctuidae

    MJT. Assunção-Albuquerque

    Full Text Available There is much evidence to support that Mocis latipes larvae (Guenèe, 1852 are the most dangerous pasture pest and usually cause large environmental losses. However, no studies have been carried out to identify the instars during which this moth causes the most damage to the environment. Here we calculate M. latipes larval energy budget to assess its consumption across all instars and estimate the consumption/amount of plant biomass required to complete its larval development. Assimilation, respiration, consumption, excretion, gross growth efficiency and net growth efficiency were calculated. Pearson correlations were used to identify the best predictors that influenced larval growth and weight. Across all instars consumption increased exponentially, especially during the last phase. M. latipes larvae consumed ca 13.8% of total food from the first to the fifth instar, whereas during the sixth instars these larvae consumed ca 72.6%. Results also show that the best gross growth and net growth efficiency were obtained when larvae reached the fifth instar. The results also show that one larva of Mocis latipes consumes 1.02 g (dry weight of Paspalum maritimum (Trin in 19 days. Overall, our results indentified the sixth instar as the most destructive instar of this insect. Thus, once we know the most destructive instars of this pest, measures can be taken to disable M. latipes larval development and consequently stop their increase in plant consumption, reducing ecological and economic damage. This knowledge may eventually lead to reduced agricultural damage and contribute to sustainable farming strategies.

  7. The fish sexual development test: an OECD test guideline proposal with possible relevance for environmental risk assessment. Results from the validation programme

    Holbech, Henrik; Brande-Lavridsen, Nanna; Kinnberg, Karin Lund

    2010-01-01

    The Fish Sexual Development Test (FSDT) has gone through two validations as an OECD test guideline for the detection of endocrine active chemicals with different modes of action. The validation has been finalized on four species: Zebrafish (Danio rerio), Japanese medaka (Oryzias latipes), three s...... as a population relevant endpoint and the results of the two validation rounds will be discussed in relation to environmental risk assessment and species selection....... for histology. For all three methods, the fish parts were numbered and histology could therefore be linked to the vitellogenin concentration in individual fish. The two core endocrine relevant endpoints were vitellogenin concentrations and phenotypic sex ratio. Change in the sex ratio is presented...

  8. Links between persistent DNA damage, genome instability, and aging

    Dynan, William S. [Emory Univ., Atlanta, GA (United States). Dept. of Radiation Oncology

    2016-11-14

    The goal of this study was to examine long-term effects of low-dose radiation exposure. One of the hypotheses was that radiation exposure would accelerate the normal aging process. The study was jointly funded by NASA and examined both low-LET radiation (γ-rays) and high-LET radiation (1000 MeV/nucleon 56Fe ions) at doses of 0.1 Gy and up. The work used the Japanese medaka fish (Oryzias latipes), as a vertebrate model organism that can be maintained in large numbers at low cost for lifetime studies. Like other small laboratory fish, Japanese medaka share many anatomical and histological characteristics with other vertebrates, and a variety of genetic and genomic resources are available. Some work also used the zebrafish (Danio rerio), another widely used laboratory model organism.

  9. Reproductive and transgenerational toxicities of phenanthrene on female marine medaka (Oryzias melastigma).

    Sun, Lingbin; Zuo, Zhenghong; Chen, Meng; Chen, Yixin; Wang, Chonggang

    2015-05-01

    Phenanthrene (PHE) is one of the most abundant polycyclic aromatic hydrocarbons in the aquatic environment and often results from oil spills. To assess the effects of PHE on fish, marine medaka (Oryzias melastigma) was exposed to PHE at 0.06, 0.6, 6 and 60 μg/L. The reproductive functions and transgenerational effects were investigated. After 80 days exposure, the percentage of previtellogenic and vitellogenic oocytes in the ovary showed a significant decrease in the 0.06 and 60 μg/L groups. The mRNA levels of salmon-type gonadotropin releasing hormone, the follicle-stimulating hormone FSHβ, and the luteinizing hormone LHβ in the brain; the cytochrome P450 aromatase gene CYP19A and the estrogen receptor α (ERα) in the ovary; and ERα and vitellogenin VTG1 and 2 in the liver all exhibited significant down-regulation in the 0.06 and 60 μg/L groups, but did not significantly change in the 6 μg/L group compared to the control, which was quite consistent with development of the oocytes. A significant elevation of PHE accumulation in the brain in the 0.06 and 60 μg/L groups gave a reasonable explanation for the nonmonotonic dose-response and also elucidated the action pathway via the brain-pituitary-gonadal axis. The reduction of the time to hatch and the increased cardiac rhythm of embryos were in accord with the PHE accumulative levels in the eggs. The results demonstrated that exposure to PHE at both low and high concentrations can inhibit ovary development. In addition, PHE can be maternally transferred to embryos and influence the health and sustainability of the next generation. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Impact of ocean acidification on the early development and escape behavior of marine medaka (Oryzias melastigma).

    Wang, Xiaojie; Song, Lulu; Chen, Yi; Ran, Haoyu; Song, Jiakun

    2017-10-01

    Ocean acidification is predicted to affect a wide diversity of marine organisms. However, no studies have reported the effects of ocean acidification on Indian Ocean fish. We have used the Indian Ocean medaka (Oryzias melastigma) as a model species for a marine fish that lives in coastal waters. We investigated the impact of ocean acidification on the embryonic development and the stereotyped escape behavior (mediated by the Mauthner cell) in newly hatched larvae. Newly fertilized eggs of medaka were reared in seawater at three different partial pressures of carbon dioxide (pCO 2 ): control at 450 μatm, moderate at 1160 μatm, and high at 1783 μatm. Hatch rates, embryonic duration, and larval malformation rates were compared and were not significantly different between the treatments and the control. In the high pCO 2 group, however, the yolks of larvae were significantly smaller than in the control group, and the newly hatched larvae were significantly longer than the larvae in the control. In the moderate pCO 2 group, the eye distance decreased significantly. No significantly negative growth effects were observed in the larvae when exposed to pCO 2 levels that are predicted as a result of ocean acidification in the next 100-200 years. Larvae reared under control conditions readily produced C-start escape behavior to mechanosensory stimuli; however, in the moderate and high pCO 2 experimental groups, the probabilities of C-start were significantly lower than those of the control group. Therefore, the sensory integration needed for the C-start escape behavior appears to be vulnerable to ocean acidification. Altered behavior in marine larval fish, particularly behaviors involved in escape from predation, could have potentially negative implications to fish populations, and, further, to the marine ecosystems at the levels of CO 2 projected for the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Chronic bisphenol A exposure alters behaviors of zebrafish (Danio rerio)

    Wang, Ju; Wang, Xia; Xiong, Can; Liu, Jian; Hu, Bing; Zheng, Lei

    2015-01-01

    The adult zebrafish (Danio rerio) were exposed to treated-effluent concentration of bisphenol A (BPA) or 17β-estradiol (E2) for 6 months to evaluate their effects on behavioral characteristics: motor behavior, aggression, group preference, novel tank test and light/dark preference. E2 exposure evidently dampened fish locomotor activity, while BPA exposure had no marked effect. Interestingly, BPA-exposed fish reduced their aggressive behavior compared with control or E2. Both BPA and E2 exposure induced a significant decrease in group preference, as well as a weaker adaptability to new environment, exhibiting lower latency to reach the top, more entries to the top, longer time spent in the top, fewer frequent freezing, and fewer erratic movements. Furthermore, the circadian rhythmicity of light/dark preference was altered by either BPA or E2 exposure. Our results suggest that chronic exposure of treated-effluent concentration BPA or E2 induced various behavioral anomalies in adult fish and enhanced ecological risk to wildlife. - Highlights: • BPA exposure induces various adult behavioral anomalies. • BPA exposure decreases social interaction and environmental adaptation of zebrafish. • BPA exposure increases ecological risk to wildlife. - Chronic bisphenol A exposure alters zebrafish behaviors.

  12. Resveratrol radiomodifier effect on Danio rerio embriolarval assay

    Damasceno, Kelme C.; Mamede, Fernanda C.S.; Cavalcante, Adriana K.; Rogero, Sizue O.; Rogero, José R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ferreira, Monica L., E-mail: kelmecardoso@gmail.com, E-mail: monica.lopesferreira@butantan.gov.br [Instituto Butantan, São Paulo, SP (Brazil)

    2017-07-01

    The ionizing radiation can cause fatal damages to cells by the direct interaction with DNA and RNA or a series of toxic reactions occasioning chemical and biological changes. There are compounds with radioprotective potential, like resveratrol. For use these compounds it is necessary to know their toxicity and interaction with the organism. Resveratrol is a substance found in peanuts, grapes and wine and its production occurs in plants as a response to physical, chemical and biological stress. Some studies have indicated that it has many health benefits. Danio rerio (zebrafish) is a vertebrate animal and has become the model of several studies related to human diseases, due to its genomes similarity of 70 %, rapid embryonic development and the transparency of the eggs, which make it possible to observe the effects during the test period. The aim of the present study was to verify the resveratrol radiomodifier effect on zebrafish during the embryolarval development by modified Fish Embryo Acute Toxicity (FET) based on OECD236 and the obtained lethal concentration of resveratrol (LC50) was 66.9 mg.L{sup -1}. Before, to understand the effects of radiation, was carried out the gamma radiation lethal dose (LD50) assay and the LD50 was 25 Gy. With these results the project will continue later to finish the study of the radiomodifier effect of resveratrol in the presence of gamma radiation. (author)

  13. Natural preference of zebrafish (Danio rerio for a dark environment

    Serra E.L.

    1999-01-01

    Full Text Available The zebrafish (Danio rerio has been used as a model in neuroscience but knowledge about its behavior is limited. The aim of this study was to determine the preference of this fish species for a dark or light environment. Initially we used a place preference test and in a second experiment we applied an exit latency test. A two-chamber aquarium was used for the preference test. The aquarium consisted of a black chamber and a white chamber. In the first experiment the animal was placed in the aquarium and the time spent in the two compartments was recorded for 10 min. More time was spent in the black compartment (Wilcoxon matched-pairs signed-rank test, T = 7, N1 = N2 = 18, P = 0.0001. In the second experiment the animal was placed in the black or white compartment and the time it took to go from the initial compartment to the opposite one was recorded. The test lasted a maximum of 10 min. The results showed that the animal spent more time to go from the black to the white compartment (Mann-Whitney rank sum test, T = 48, N1 = 9, N2 = 8, P<0.0230. These data suggest that this fish species has a natural preference for a dark environment and this characteristic can be very useful for the development of new behavioral paradigms for fish.

  14. Resveratrol radiomodifier effect on Danio rerio embriolarval assay

    Damasceno, Kelme C.; Mamede, Fernanda C.S.; Cavalcante, Adriana K.; Rogero, Sizue O.; Rogero, José R.; Ferreira, Monica L.

    2017-01-01

    The ionizing radiation can cause fatal damages to cells by the direct interaction with DNA and RNA or a series of toxic reactions occasioning chemical and biological changes. There are compounds with radioprotective potential, like resveratrol. For use these compounds it is necessary to know their toxicity and interaction with the organism. Resveratrol is a substance found in peanuts, grapes and wine and its production occurs in plants as a response to physical, chemical and biological stress. Some studies have indicated that it has many health benefits. Danio rerio (zebrafish) is a vertebrate animal and has become the model of several studies related to human diseases, due to its genomes similarity of 70 %, rapid embryonic development and the transparency of the eggs, which make it possible to observe the effects during the test period. The aim of the present study was to verify the resveratrol radiomodifier effect on zebrafish during the embryolarval development by modified Fish Embryo Acute Toxicity (FET) based on OECD236 and the obtained lethal concentration of resveratrol (LC50) was 66.9 mg.L -1 . Before, to understand the effects of radiation, was carried out the gamma radiation lethal dose (LD50) assay and the LD50 was 25 Gy. With these results the project will continue later to finish the study of the radiomodifier effect of resveratrol in the presence of gamma radiation. (author)

  15. Brain Transcriptomic Response to Social Eavesdropping in Zebrafish (Danio rerio.

    João Sollari Lopes

    Full Text Available Public information is widely available at low cost to animals living in social groups. For instance, bystanders may eavesdrop on signaling interactions between conspecifics and use it to adapt their subsequent behavior towards the observed individuals. This social eavesdropping ability is expected to require specialized mechanisms such as social attention, which selects social information available for learning. To begin exploring the genetic basis of social eavesdropping, we used a previously established attention paradigm in the lab to study the brain gene expression profile of male zebrafish (Danio rerio in relation to the attention they paid towards conspecifics involved or not involved in agonistic interactions. Microarray gene chips were used to characterize their brain transcriptomes based on differential expression of single genes and gene sets. These analyses were complemented by promoter region-based techniques. Using data from both approaches, we further drafted protein interaction networks. Our results suggest that attentiveness towards conspecifics, whether interacting or not, activates pathways linked to neuronal plasticity and memory formation. The network analyses suggested that fos and jun are key players on this response, and that npas4a, nr4a1 and egr4 may also play an important role. Furthermore, specifically observing fighting interactions further triggered pathways associated to a change in the alertness status (dnajb5 and to other genes related to memory formation (btg2, npas4b, which suggests that the acquisition of eavesdropped information about social relationships activates specific processes on top of those already activated just by observing conspecifics.

  16. Pharmacological analyses of learning and memory in zebrafish (Danio rerio).

    Bailey, Jordan M; Oliveri, Anthony N; Levin, Edward D

    2015-12-01

    Over the last decade, zebrafish (Danio rerio) have become valuable as a complementary model in behavioral pharmacology, opening a new avenue for understanding the relationships between drug action and behavior. This species offers a useful intermediate approach bridging the gap between in vitro studies and traditional mammalian models. Zebrafish offer great advantages of economy compared to their rodent counterparts, their complex brains and behavioral repertoire offer great translational potential relative to in vitro models. The development and validation of a variety of tests to measure behavior, including cognition, in zebrafish have set the stage for the use of this animal for behavioral pharmacology studies. This has led to research into the basic mechanisms of cognitive function as well as screening for potential cognition-improving drug therapies, among other lines of research. As with all models, zebrafish have limitations, which span pharmacokinetic challenges to difficulties quantifying behavior. The use, efficacy and limitations associated with a zebrafish model of cognitive function are discussed in this review, within the context of behavioral pharmacology. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Evaluation of anaesthetic protocols for laboratory adult zebrafish (Danio rerio.

    Tânia Martins

    Full Text Available In the last decades, the use of zebrafish (Danio rerio in biomedical research has increased. Anaesthesia is daily used in fish during experimental procedures to avoid discomfort, stress or pain. Also, fish welfare and the reliability of results can be compromised if an unsuitable anaesthetic protocol is used. Therefore, we aimed to refine anaesthetic protocols to be used in adult zebrafish by evaluating the efficacy of different anaesthetics, used alone or in combination. For that, zebrafish were randomly assigned to 8 different groups: 100 μg/mLMS-222 (MS; 0.2 μg/mL etomidate (E; 0.2 μg/mL etomidate + 100 μg/mL lidocaine (E+L; 1.25 μg/mL propofol (P; 1.25 μg/mL propofol + 100 μg/mL lidocaine (P+L; 100 μg/mL ketamine (K; 100 μg/mL ketamine + 1.25 μg/mL medetomidine (K+M; and 100 μg/mL ketamine + 1.25 μg/mL medetomidine/3.125 μg/mL atipamezole (K+M/A. The animals were placed in an anaesthetic water bath, then, the following parameters were registered: time for equilibrium loss and anaesthesia induction, loss of sensitivity to soft and painful stimuli, respiratory rate, recovery time, and activity after recovery. The combined forms of E+L, P+L and K+M were the fastest to induce a surgical anaesthetic stage. Nevertheless, E+L induced respiratory depression, while K+M was shown to have the longer recovery time compared to MS-222, even when atipamezole was added. In conclusion, the P+L combination was shown to provide good anaesthesia with analgesia, without causing a major respiratory depression, providing as well a quick recovery, similar to MS-222.

  18. Fluoride caused thyroid endocrine disruption in male zebrafish (Danio rerio).

    Jianjie, Chen; Wenjuan, Xue; Jinling, Cao; Jie, Song; Ruhui, Jia; Meiyan, Li

    2016-02-01

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect thyroid endocrine system, but little is known of such effects or underlying mechanisms in fish. In the present study, we evaluated the effects of fluoride on growth performance, thyroid histopathology, thyroid hormone levels, and gene expressions in the HPT axis in male zebrafish (Danio rerio) exposed to different determined concentrations of 0.1, 0.9, 2.0 and 4.1 M of fluoride to investigate the effects of fluoride on thyroid endocrine system and the potential toxic mechanisms caused by fluoride. The results indicated that the growth of the male zebrafish used in the experiments was significantly inhibited, the thyroid microtrastructure was changed, and the levels of T3 and T4 were disturbed in fluoride-exposed male fish. In addition, the expressional profiles of genes in HPT axis displayed alteration. The expressions of all studied genes were significantly increased in all fluoride-exposed male fish after exposure for 45 days. The transcriptional levels of corticotrophin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroglobulin (TG), sodium iodide symporter (NIS), iodothyronine I (DIO1), and thyroid hormone receptor alpha (TRα) were also elevated in all fluoride-exposed male fish after 90 days of exposure, while the inconsistent expressions were found in the mRNA of iodothyronineⅡ (DIO2), UDP glucuronosyltransferase 1 family a, b (UGT1ab), transthyretin (TTR), and thyroid hormone receptor beta (TRβ). These results demonstrated that fluoride could notably inhibit the growth of zebrafish, and significantly affect thyroid endocrine system by changing the microtrastructure of thyroid, altering thyroid hormone levels and endocrine-related gene expressions in male zebrafish. All above indicated that fluoride could pose a great threat to thyroid endocrine system, thus detrimentally affected the normal function of thyroid of male zebrafish. Copyright © 2015

  19. Uranium-induced sensory alterations in the zebrafish Danio rerio

    Faucher, K., E-mail: kfaucher@hotmail.fr [Laboratoire d' ecotoxicologie des radionucleides (LECO), Institut de Radioprotection et Surete Nucleaire, Centre de Cadarache, Batiment 186, BP3, 13115 Saint Paul lez Durance (France); Floriani, M.; Gilbin, R.; Adam-Guillermin, C. [Laboratoire d' ecotoxicologie des radionucleides (LECO), Institut de Radioprotection et Surete Nucleaire, Centre de Cadarache, Batiment 186, BP3, 13115 Saint Paul lez Durance (France)

    2012-11-15

    The effect of chronic exposure to uranium ions (UO{sub 2}{sup 2+}) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 {mu}g l{sup -1} for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes > olfactory bulbs > skin > muscles > brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

  20. Toxicological effects of graphene oxide on adult zebrafish (Danio rerio)

    Souza, Jaqueline P., E-mail: souza.jaqueline@gmail.com; Baretta, Jéssica F.; Santos, Fabrício; Paino, Ieda M.M.; Zucolotto, Valtencir

    2017-05-15

    Highlights: • Graphene oxide exposure caused apoptotic and necrotic stages in zebrafish gill cells. • Graphene oxide induced reactive oxygen generation in zebrafish gill cells. • Gill and liver tissues suffered injuries after graphene oxide chronic exposure. • Zebrafish blood cells did not present DNA damages after graphene oxide exposure. - Abstract: Graphene exhibits unique physical and chemical properties that facilitate its application in many fields, including electronics and biomedical areas. However, the use of graphene and its derivatives could result in accumulation in aquatic environments, and the risks posed by these compounds for organisms are not completely understood. In this study, we investigated the effects of graphene oxide (GO) on adult zebrafish (Danio rerio). Experimental fish were exposed to 2, 10 or 20 mg L{sup −1} GO, and the cytotoxicity, genotoxicity and oxidative stress were assessed. The morphology of the gills and liver tissues was also analyzed. Graphene oxide exposure led to an increase in the number of gill cells that were in early apoptotic and necrotic stages, but genotoxicity was not observed in blood cells. We also observed the generation of Reactive Oxygen Species (ROS) in gill cells. Structural analysis revealed injuries to gill tissues, including a dilated marginal channel, lamellar fusion, clubbed tips, swollen mucocytes, epithelial lifting, aneurysms, and necrosis. Liver tissues also presented lesions such as peripherally located nuclei. Furthermore, hepatocytes exhibited a non-uniform shape, picnotic nuclei, vacuole formation, cell rupture, and necrosis. Our results showed that sub-lethal doses of graphene oxide could be harmful to fish species and thus represent risks for the aquatic food chain.

  1. Evaluation of visible implant elastomer tags in zebrafish (Danio rerio

    Claudia Hohn

    2013-11-01

    The use of the visible implant elastomer (VIE tagging system in zebrafish (Danio rerio was examined. Two tag orientations (horizontal and vertical at the dorsal fin base were tested for tag retention, tag fragmentation and whether VIE tags affected growth and survival of juvenile zebrafish (1–4 month post hatch. Six tag locations (abdomen, anal fin base, caudal peduncle, dorsal fin base, pectoral fin base, isthmus and 5 tag colors (yellow, red, pink, orange, blue were evaluated for ease of VIE tag application and tag visibility in adult zebrafish. Long-term retention (1 year and multiple tagging sites (right and left of dorsal fin and pectoral fin base were examined in adult zebrafish. Lastly, survival of recombination activation gene 1−/− (rag1−/− zebrafish was evaluated after VIE tagging. The best tag location was the dorsal fin base, and the most visible tag color was pink. Growth rate of juvenile zebrafish was not affected by VIE tagging. Horizontal tagging is recommended in early stages of fish growth (1–2 months post hatch. VIE tags were retained for 1 year and tagging did not interfere with long-term growth and survival. There was no mortality associated with VIE tagging in rag1−/− zebrafish. The VIE tagging system is highly suitable for small-sized zebrafish. When familiar with the procedure, 120 adult zebrafish can be tagged in one hour. It does not increase mortality in adult zebrafish or interfere with growth in juvenile or adult zebrafish.

  2. Effects of chronic ammonia exposure on ammonia metabolism and excretion in marine medaka Oryzias melastigma.

    Gao, Na; Zhu, Limei; Guo, Zhiqiang; Yi, Meisheng; Zhang, Li

    2017-06-01

    Ammonia is highly toxic to aquatic organisms, but whether ammonia excretion or ammonia metabolism to less toxic compounds is the major strategy for detoxification in marine fish against chronic ammonia exposure is unclear to date. In this study, we investigated the metabolism and excretion of ammonia in marine medaka Oryzias melastigma during chronic ammonia exposure. The fish were exposed to 0, 0.1, 0.3, 0.6, and 1.1 mmol l -1  NH 4 Cl spiked seawater for 8 weeks. Exposure of 0.3-1.1 mmol l -1  NH 4 Cl had deleterious effects on the fish, including significant reductions in growth, feed intake, and total protein content. However, the fish could take strategies to detoxify ammonia. The tissue ammonia (T Amm ) in the 0.3-1.1 mmol l -1  NH 4 Cl treatments was significantly higher than those in the 0 and 0.1 mmol l -1  NH 4 Cl treatments after 2 weeks of exposure, but it recovered with prolonged exposure time, ultimately reaching the control level after 8 weeks. The amino acid catabolic rate decreased to reduce the gross ammonia production with the increasing ambient ammonia concentration. The concentrations of most metabolites remained constant in the 0-0.6 mmol l -1  NH 4 Cl treatments, whereas 5 amino acids and 3 energy metabolism-related metabolites decreased in the 1.1 mmol l -1  NH 4 Cl treatment. J Amm steadily increased in ambient ammonia from 0 to 0.6 mmol l -1 and slightly decreased when the ambient ammonia concentration increased to 1.1 mmol l -1 . Overall, marine medaka cope with sublethal ammonia environment by regulating the tissue T Amm via reducing the ammonia production and increasing ammonia excretion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Phototoxicity of TiO2 nanoparticles to zebrafish (Danio rerio) is dependent on life stage

    The zebrafish (Danio rerio) embryo has been increasingly used as a model to evaluate toxicity of manufactured nanomaterials. Many studies indicate that the embryo chorion may protect animals from toxic effects of nanomaterials, suggesting that post-hatch life stages may be more s...

  4. Toxicity of tetrabromobisphenol A (TBBPA) in zebrafish (Danio rerio) in a partial life-cycle test.

    Kuiper, R V; Brandhof, E J van den; Leonards, P E G; Ven, L T M van der; Wester, P W; Vos, J G

    2006-01-01

    Toxicological effects of the widely used flame retardant, tetrabromobisphenol A (TBBPA) were assessed in a partial life-cycle test with zebrafish (Danio rerio). Exposure of adult fish during 30 days to water-borne TBBPA in nominal concentrations ranging from 0 (control) to 1.5 muM was followed by

  5. Toxicity of tetrabromobisphenol A (TBBPA) in zebrafish (Danio rerio) in a partial life-cycle test

    Kuiper, R.V.; Brandhof, Van den E.J.; Leonards, P.E.G.; Ven, van der L.T.M.; Wester, P.W.; Vos, J.G.

    2007-01-01

    Toxicological effects of the widely used flame retardant, tetrabromobisphenol A (TBBPA) were assessed in a partial life-cycle test with zebrafish (Danio rerio). Exposure of adult fish during 30 days to water-borne TBBPA in nominal concentrations ranging from 0 (control) to 1.5 ¿M was followed by

  6. Endocrine-disrupting effect of the ultraviolet filter benzophenone-3 in zebrafish, Danio rerio

    Kinnberg, Karin Lund; Petersen, Gitte I.; Albrektsen, Mette

    2015-01-01

    of BP-3 in zebrafish (Danio rerio) in the Fish Sexual Development Test (Organisation for Economic Co-operation and Development TG 234) and a 12 day adult male zebrafish study. In TG 234, exposure from 0 to 60 d posthatch caused a monotone dose-dependent skewing of the phenotypic sex ratio towards less...

  7. Reproductive impairment in the zebrafish, Danio rerio, upon chronic exposure to 1,2,3-trichlorobenzene.

    Roex, E.W.M.; Giovannangelo, M.E.C.A.; van Gestel, C.A.M.

    2001-01-01

    Most organic pollutants are supposed to act via the mechanism of nonpolar narcosis upon acute exposure. Because the chronic effects of these compounds are still relatively unknown, in this study a chronic toxicity experiment was performed with zebrafish, Danio rerio, exposed to 1, 2,

  8. Gene Expression Profiling of Androgen Receptor Antagonists Flutamide and Vinclozolin in Zebrafish (Danio rerio) Gonads

    The studies presented in this manuscript focus on characterization of genomic responses to anti-androgens in zebrafish (Danio rerio). Research of the effects of anti-androgens in fish has been characterized by a heavy reliance on apical endpoints, and molecular mechanisms of acti...

  9. A single Danio rerio hars gene encodes both cytoplasmic and mitochondrial histidyl-tRNA synthetases.

    Ashley L Waldron

    Full Text Available Histidyl tRNA Synthetase (HARS is a member of the aminoacyl tRNA synthetase (ARS family of enzymes. This family of 20 enzymes is responsible for attaching specific amino acids to their cognate tRNA molecules, a critical step in protein synthesis. However, recent work highlighting a growing number of associations between ARS genes and diverse human diseases raises the possibility of new and unexpected functions in this ancient enzyme family. For example, mutations in HARS have been linked to two different neurological disorders, Usher Syndrome Type IIIB and Charcot Marie Tooth peripheral neuropathy. These connections raise the possibility of previously undiscovered roles for HARS in metazoan development, with alterations in these functions leading to complex diseases. In an attempt to establish Danio rerio as a model for studying HARS functions in human disease, we characterized the Danio rerio hars gene and compared it to that of human HARS. Using a combination of bioinformatics, molecular biology, and cellular approaches, we found that while the human genome encodes separate genes for cytoplasmic and mitochondrial HARS protein, the Danio rerio genome encodes a single hars gene which undergoes alternative splicing to produce the respective cytoplasmic and mitochondrial versions of Hars. Nevertheless, while the HARS genes of humans and Danio differ significantly at the genomic level, we found that they are still highly conserved at the amino acid level, underscoring the potential utility of Danio rerio as a model organism for investigating HARS function and its link to human diseases in vivo.

  10. Crystal structure of an eIF4G-like protein from Danio rerio

    Bae, Euiyoung; Bitto, Eduard; Bingman, Craig A.; McCoy, Jason G.; Wesenberg, Gary E.; Phillips, Jr., George N. (UW)

    2012-04-18

    The gene LOC 91917 Danio rerio (zebrafish) encodes a protein annotated in the UniProt knowledgebase as the middle domain of eukaryotic initiation factor 4G domain containing protein b (MIF4Gdb). Its molecular weight is 25.8 kDa, and it comprises 222 amino acid residues. BLAST searches revealed homologues of D. rerio MIF4Gdb in many eukaryotes including humans. The homologue sand MIF4Gdb were identified as members of the Pfam family, MIF4G (PF2854), which is named after the middle domain of eukaryotic initiation factor 4G (eIF4G). eIF4G is a component of eukaryotic translational initiation complex, and contains binding sites for other initiation factors, suggesting its critical role in translational initiation. The MIF4G domain also occurs in several other proteins involved in RNA metabolism, including the Nonsense-mediated mRNA decay 2 protein (NMD2/UPF2), and the nuclear cap-binding protein 80-kDa subunit (CBP80). Sequence and structure analysis of the MIF4G domains in many proteins indicate that the domain assumes an all helical fold and has tandem repeated motifs. The zebrafish protein described here has homology to domains of other proteins variously referred to as NIC-containing proteins (NMD2, eIF4G, CBP80). The biological function of D. rerio MIF4Gdb has not yet been experimentally characterized, and the annotation is based on amino acid sequence comparison. D. rerio MIF4Gdb did not share more than 25% sequence identity with any protein for which the three-dimensional structure is known and was selected as a target for structure determination by the Center for Eukaryotic Structural Genomics (CESG). Here, they report the crystal structure of D. rerio MIF4Gdb (UniGene code Dr.79360, UniProt code Q5EAQ1, CESG target number GO.79294).

  11. Comment: 219 [Taxonomy Icon

    Full Text Available Japanese medaka Oryzias latipes Oryzias_latipes_L.png 219.png Taxonomy icon (c) Database Center for Life Sci...ence licensed under CC Attribution2.1 Japan アイコン:メダカ HNI-Ⅱ系統バージョン bando 2010/02/15 15:31:07 2010/02/16 09:53:27 ...

  12. Evaluation of mutagenicity and metabolism-mediated cytotoxicity of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

    Rodrigo R. Kitagawa

    Full Text Available A large number of quinones have been associated with antitumor, antibacterial, antimalarial, and antifungal activities. Results of previous studies of 5-methoxy-3,4-dehydroxanthomegnin, a naphthoquinone isolated from Paepalanthus latipes Silveira, Eriocaulaceae, revealed antitumor, antibacterial, immunomodulatory, and antioxidant activities. In this study, we assessed the mutagenicity and metabolism-mediated cytotoxicity of 5-methoxy-3,4-dehydroxanthomegnin by using the Ames test and a microculture neutral red assay incorporating an S9 fraction (hepatic microsomal fraction and cofactors, respectively. We also evaluated the mutagenic activity in Salmonella typhimurium strains TA100, TA98, TA102, and TA97a, as well as the cytotoxic effect on McCoy cells with and without metabolic activation in both tests. Results indicated that naphthoquinone does not cause mutations by substitution or by addition and deletion of bases in the deoxyribonucleic acid sequence with and without metabolic activation. As previously demonstrated, the in vitro cytotoxicity of 5-methoxy-3,4-dehydroxanthomegnin to McCoy cells showed a significant cytotoxic index (CI50 of 11.9 μg/ml. This index was not altered by addition of the S9 fraction, indicating that the S9 mixture failed to metabolically modify the compound. Our results, allied with more specific biological assays in the future, would contribute to the safe use of 5-methoxy-3,4-dehydroxanthomegnin, compound that has showed in previous studies beneficial properties as a potential anticancer drug.

  13. Labeling fish with an activable element through their diet. [samarium

    Michibata, Hitoshi (Toyama Univ. (Japan). Faculty of Science)

    1981-10-01

    Stable samarium, one of the rare earth elements, was fed to medaka (Oryzias latipes) and goldfish (Carassius auratus). The concentration of samarium in the labeled fish was determined by neutron activation analysis. In O. latipes, samarium was detectable even 1 yr after the labeled diet was eaten. In C. auratus, samarium was retained in the fifth brachial arch, scales, and gills.

  14. Efficacy of Cleaning and Disinfection Procedures in a Zebrafish (Danio rerio) Facility

    Garcia, Rachel L; Sanders, George E

    2011-01-01

    Appropriate cleaning and disinfection procedures in zebrafish (Danio rerio) laboratories are crucial in preventing the spread of aquatic animal pathogens and minimizing the build-up of waste products and biologic matter. The procedures selected should accomplish these goals and incorporate the individual needs of various laboratories. In this study of a single zebrafish facility, we assessed the efficacy of 2 different cleaning and disinfection procedures for nets, tanks, and lids. ATP levels...

  15. Effect of mercury and cadmium on early life stages of Java medaka (Oryzias javanicus): A potential tropical test fish

    Ismail, Ahmad; Yusof, Shahrizad

    2011-01-01

    Research highlights: → Early life stages of Java medaka show high sensitivity to Cd and Hg. → Exposure of the early life stages caused several developmental impairments. → Java medaka is suitable to be established as test organism for ecotoxicology. → Results of testing using this fish reflect the environment of the tropical region. - Abstract: Several organisms have been used as indicators, bio-monitoring agents or test organisms in ecotoxicological studies. A close relative of the well established Japanese medaka, the Java medaka (Oryzias javanicus), has the potential to be a test organism. The fish is native to the estuaries of the Malaysian Peninsula, Thailand, Indonesia and Singapore. In this study, newly fertilised eggs were exposed to different concentrations of Cd and Hg. Observations were done on the development of the embryos. Exposure to low levels of Cd and Hg (0.01-0.05 ppm) resulted in several developmental disorders that led to death. Exposure to ≥1.0 ppm Cd resulted in immediate developmental arrest. The embryos of Java medaka showed tolerance to a certain extent when exposed to ≥1.0 ppm Hg compared to Cd. Based on the sensitivity of the embryos, Java medaka is a suitable test organism for ecotoxicology in the tropical region.

  16. Developmental toxicity and molecular responses of marine medaka (Oryzias melastigma) embryos to ciguatoxin P-CTX-1 exposure.

    Yan, Meng; Leung, Priscilla T Y; Ip, Jack C H; Cheng, Jin-Ping; Wu, Jia-Jun; Gu, Jia-Rui; Lam, Paul K S

    2017-04-01

    Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96h-LD 50 value was estimated for eleuthero-embryos (1.32ngg -1 ) than that for embryos (1.71ngg -1 ), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Hepatic Proteomic Responses in Marine Medaka ( Oryzias melastigma ) Chronically Exposed to Antifouling Compound Butenolide [5-octylfuran-2(5H)-one] or 4,5-Dichloro-2- N -Octyl-4-Isothiazolin-3-One (DCOIT)

    Chen, Lianguo; Sun, Jin; Zhang, Huoming; Au, Doris W. T.; Lam, Paul K. S.; Zhang, Weipeng; Bajic, Vladimir B.; Qiu, Jian-Wen; Qian, Pei-Yuan

    2015-01-01

    function in marine organisms. In the present study, we investigated the hepatic protein expression profiles of both male and female marine medaka (Oryzias melastigma) exposed to low concentrations of DCOIT at 2.55 mu g/L (0.009 mu M) or butenolide, a

  18. International survey on the use and welfare of zebrafish Danio rerio in research.

    Lidster, K; Readman, G D; Prescott, M J; Owen, S F

    2017-05-01

    A survey was conducted regarding zebrafish Danio rerio use for scientific research with a focus on: anaesthesia and euthanasia; housing and husbandry; breeding and production; refinement opportunities. A total of 98 survey responses were received from laboratories in 22 countries in Europe, North America, South America, Asia and Australia. There appears a clear and urgent need to identify the most humane methods of anaesthesia and euthanasia. Aversive responses to MS-222 were widely observed raising concerns about the use of this anaesthetic for D. rerio. The use of anaesthesia in fin clipping for genetic identification is widely practised and there appears to be an opportunity to further develop less invasive methods and refine this process. Optimization (and potentially standardization) of feeding is an area for further investigation. Given that diet and body condition can have such profound effects on results of experiments, differences in practice could have significant scientific implications. Further research into transition between dark and light phases in the laboratory appears to represent an opportunity to establish best practice. Plants and gravel were not considered practical by many laboratories. The true value and benefits need to be established and communicated. Overproduction is a concern both from ethical and financial viewpoints. There is an opportunity to further reduce wastage of D. rerio. There are clear concerns and opportunities for the scientific community to work together to further improve the welfare of these important laboratory models. © 2017 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  19. The acute toxicity of clove oil to fish Danio rerio and Poecilia reticulata

    Petra Doleželová

    2011-01-01

    Full Text Available Clove oil (active substance eugenol is an anaesthetic used in aquaculture for stress prevention and prevention of mechanical damage during veterinary procedures. The aim of this study was to determine the acute toxicity of clove oil in two aquarium fish species - zebrafish (Danio rerio and guppy (Poecilia reticulata, which are considered the most commonly used model organisms in toxicity testing. The semi-static method according to OECD no. 203 (Fish, Acute toxicity test was used for testing the toxicity of clove oil for juvenile fish. A series of 5 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The results obtained (number of dead individuals at particular test concentrations were subjected to a probit analysis using the EKO-TOX 5.2 program in order to determine 96hLC50 clove oil values. The significance of the difference between 96hLC50 values in D. rerio and P. reticulata was tested using the Mann-Whitney non-parametric test. The 96hLC50 mean value for clove oil was 18.2 ± 5.52 mg·l–1 in juvenile D. rerio and 21.7 ± 0.8 mg·l–1 in P. reticulata. In spite of variability in clove oil composition, acute toxicity values of clove oil for juvenile stages of both fish species were comparable. The results did not show different sensitivities to clove oil in tested fish species. This is the first similar study in these fish species.

  20. The effects of fish gender on susceptibility to acute Streptococcus agalactiae infection in Javanese medaka Oryzias javanicus.

    Amal, M N A; Zarif, S T; Suhaiba, M S; Aidil, M R M; Shaqinah, N N; Zamri-Saad, M; Ismail, A

    2017-12-05

    This study describes the susceptibility of different fish gender following acute Streptococcus agalactiae infection by using Javanese medaka Oryzias javanicus as test fish. The fish were grouped into four groups, which were: (1) all-male; (2) all-female; (3) mixed-gender (1 male: 1 female ratio); and (4) control non-infected (1 male: 1 female ratio). The fish in group 1, 2 and 3 were intraperitoneally exposed to 5.4 × 10 8  CFU/mL of S. agalactiae, while for group 4, the fish were exposed using sterile broth. The main clinical signs and histopathological changes of infected Javanese medaka were commonly observed in S. agalactiae infected fishes. However, no difference on clinical signs and histopathological changes of fish in group 1, 2 and 3 were noticed. The Javanese medaka mortality in group 1, 2 and 3 were observed from 4 h post infection (hpi) to 6 hpi, with the cumulative mortality from 3% to 30%. Then, the mortality increased at 12 hpi, with the range from 53% to 80%. However, 100% of the infected fish dead at 24 hpi. No clinical sign, histopathological change and fish mortality recorded in group 4. Generally, the clinical signs, mortality patterns, cumulative mortality and histopathological changes of Javanese medaka infected by S. agalactiae did not show any difference between the all-male, all-female and mixed-gender groups. This indicates that the susceptibility of fish to S. agalactiae infection is not influenced by their gender. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The effect of fish gender on susceptibility to acute Streptococcus agalactiae infection in Javanese medaka Oryzias javanicus.

    Amal, M N A; Zarif, S T; Suhaiba, M; Aidil, M R M; Shaqinah, N N; Zamri-Saad, M; Ismail, A

    2017-12-04

    This study describes the susceptibility of different fish gender following acute Streptococcus agalactiae infection by using Javanese medaka Oryzias javanicus as test fish. The fish were grouped into four groups, which were: (1) all-male; (2) all-female; (3) mixed-gender (1 male: 1 female ratio); and (4) control non-infected (1 male: 1 female ratio). The fish in group 1, 2 and 3 were intraperitoneally exposed to 5.4 × 10 8  CFU/ml of S. agalactiae, while for group 4, the fish were exposed using sterile broth. The main clinical signs and histopathological changes of infected Javanese medaka were commonly observed in S. agalactiae infected fishes. However, no difference on clinical signs and histopathological changes of fish in group 1, 2 and 3 were noticed. The Javanese medaka mortality in group 1, 2 and 3 were observed from 4 h post infection (hpi) to 6 hpi, with the cumulative mortality from 3% to 30%. Then, the mortality increased at 12 hpi, with the range from 53% to 80%. However, 100% of the infected fish dead at 24 hpi. No clinical signs, histopathological changes and fish mortality recorded in group 4. Generally, the clinical signs, mortality patterns, cumulative mortality and histopathological changes of Javanese medaka infected by S. agalactiae did not show any difference between the all-male, all-female and mixed-gender groups. This indicates that the susceptibility of fish to S. agalactiae infection is not influenced by their gender. Copyright © 2017. Published by Elsevier Ltd.

  2. Long-term effects of a binary mixture of perfluorooctane sulfonate (PFOS) and bisphenol A (BPA) in zebrafish (Danio rerio)

    Keiter, Susanne; Baumann, Lisa; Farber, H

    2012-01-01

    aimed at evaluating the long-term effects and toxicity-increasing behavior of PFOS in vivo using the zebrafish (Danio rerio). Fish were maintained in flow-through conditions and exposed to single and binary mixtures of PFOS and the endocrine disruptor bisphenol A (BPA) at nominal concentrations of 0...

  3. GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio rerio FED A PROCESSED DIET, LIVE FOOD, OR THE COMBINATION

    Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the cu...

  4. Impacts of Different Exposure Scenarios on Transcript Abundances in Danio rerio Embryos when Investigating the Toxicological Burden of Riverine Sediments.

    Bluhm, K.; Otte, J; Yang, L.; Zinsmeister, C.; Legradi, J.B.; Keiter, S.; Kosmehl, T.; Braunbeck, T.; Straehle, U.; Hollert, H.

    2014-01-01

    Purpose: Recently, a proof-of-concept study revealed the suitability of transcriptome analyses to obtain and assess changes in the abundance of transcripts in zebrafish (Danio rerio) embryos after exposure to organic sediment extracts. The present study investigated changes in the transcript

  5. Variations in fixation techniques for field emission SEM and TEM of zebrafish (Branchydanio rerio) embryo inner and outer membranes

    Kalicharan, D; Jongebloed, WL; Rawson, DM; Zhang, TT

    1998-01-01

    The morphology of embryos of the fresh water teleost, Brachydania rerio (zebrafish), was examined in a parallel FE-SEM/TEM study, after various pre- and post-fixation regimes. Special attention was paid to the chorion, the contents of the peri-vitelline space, the plasma membrane, the syncytial

  6. Transcriptional regulatory dynamics of the hypothalamic-pituitary-gonadal axis and its peripheral pathways as impacted by the 3-beta HSD inhibitor Trilostane in zebrafish (Danio rerio)

    To identify transcription factors (TFs), members of hypothalamic-pituitary- gonadal axis (HPG-axis), TF networks and signaling pathways underlying generalized effects of 3-beta hydroxysteroid dehydrogenase (HSD3B) inhibition, reproductively mature zebrafish (Danio rerio) were exp...

  7. Hypoxia induces miR-210, leading to anti-apoptosis in ovarian follicular cells of marine medaka Oryzias melastigma

    Tse, Anna Chung-Kwan; Li, Jing-Woei; Chan, Ting-Fung; Wu, Rudolf Shiu-Sun; Lai, Keng-Po

    2015-01-01

    Highlights: • We demonstrate hypoxia induced miR-210 in ovarian follicular cells. • We show anti-apoptotic roles of miR-210 in ovarian follicular cells under hypoxia. • Apoptotic genes (DLC1, SLK, TNFRSF10B, RBM25, and USP7) are target of miR-210. • MiR-210 is vital for ovarian follicular cells proliferation in response to hypoxia. - Abstract: Hypoxia is a major global problem that impairs reproductive functions and reduces the quality and quantity of gametes and the fertilization success of marine fish. Nevertheless, the detailed molecular mechanism underlying hypoxia-induced female reproductive impairment remains largely unknown. There is increasing evidence that miRNA is vital in regulating ovarian functions and is closely associated with female fertility in humans. Certain miRNAs that regulate apoptotic genes can be induced by hypoxia, resulting in cell apoptosis. Using primary ovarian follicular cells of the marine medaka, Oryzias melastigma, as a model, we investigated the response of miR-210 to hypoxic stress in ovarian tissues to see if it would interrupt reproductive functions. A significant induction of miR-210 was found in primary ovarian follicular cells exposed to hypoxia, and gene ontology analysis further highlighted the potential roles of miR-210 in cell proliferation, cell differentiation, and cell apoptosis. A number of miR-210 target apoptotic genes, including Deleted in liver cancer 1 protein (DLC1), STE20-like serine/threonine-protein kinase (SLK), tumor necrosis factor receptor superfamily member 10b (TNFRSF10B), RNA binding motif protein 25 (RBM25), and Ubiquitin-specific-processing protease 7 (USP7), were identified. We further showed that ectopic expression of miR-210 would result in down-regulation of these apoptotic genes. On the other hand, the inhibition of miR-210 promoted apoptotic cell death and the expression of apoptotic marker – caspase 3 in follicular cells under hypoxic treatment, supporting the regulatory role of mi

  8. Hypoxia induces miR-210, leading to anti-apoptosis in ovarian follicular cells of marine medaka Oryzias melastigma

    Tse, Anna Chung-Kwan [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China); State Key Laboratory in Marine Pollution, Hong Kong SAR (China); Li, Jing-Woei; Chan, Ting-Fung [School of Life Sciences, Hong Kong Bioinformatics Centre, The Chinese University of Hong Kong, Hong Kong SAR (China); Wu, Rudolf Shiu-Sun [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China); State Key Laboratory in Marine Pollution, Hong Kong SAR (China); Lai, Keng-Po, E-mail: balllai@hku.hk [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China); State Key Laboratory in Marine Pollution, Hong Kong SAR (China)

    2015-08-15

    Highlights: • We demonstrate hypoxia induced miR-210 in ovarian follicular cells. • We show anti-apoptotic roles of miR-210 in ovarian follicular cells under hypoxia. • Apoptotic genes (DLC1, SLK, TNFRSF10B, RBM25, and USP7) are target of miR-210. • MiR-210 is vital for ovarian follicular cells proliferation in response to hypoxia. - Abstract: Hypoxia is a major global problem that impairs reproductive functions and reduces the quality and quantity of gametes and the fertilization success of marine fish. Nevertheless, the detailed molecular mechanism underlying hypoxia-induced female reproductive impairment remains largely unknown. There is increasing evidence that miRNA is vital in regulating ovarian functions and is closely associated with female fertility in humans. Certain miRNAs that regulate apoptotic genes can be induced by hypoxia, resulting in cell apoptosis. Using primary ovarian follicular cells of the marine medaka, Oryzias melastigma, as a model, we investigated the response of miR-210 to hypoxic stress in ovarian tissues to see if it would interrupt reproductive functions. A significant induction of miR-210 was found in primary ovarian follicular cells exposed to hypoxia, and gene ontology analysis further highlighted the potential roles of miR-210 in cell proliferation, cell differentiation, and cell apoptosis. A number of miR-210 target apoptotic genes, including Deleted in liver cancer 1 protein (DLC1), STE20-like serine/threonine-protein kinase (SLK), tumor necrosis factor receptor superfamily member 10b (TNFRSF10B), RNA binding motif protein 25 (RBM25), and Ubiquitin-specific-processing protease 7 (USP7), were identified. We further showed that ectopic expression of miR-210 would result in down-regulation of these apoptotic genes. On the other hand, the inhibition of miR-210 promoted apoptotic cell death and the expression of apoptotic marker – caspase 3 in follicular cells under hypoxic treatment, supporting the regulatory role of mi

  9. Influence of Propylparaben on Vitellogenesis and Sex Ratio in Juvenile Zebrafish (Danio rerio

    Přemysl Mikula

    2009-01-01

    Full Text Available The aim of the study was to evaluate the xeno-oestrogenic potential of propylparaben in vivo using zebrafish (Danio rerio. Experimental juvenile zebrafish (20 days post hatching were fed a feed containing 500, 1000, or 2000 mg kg-1 of propylparaben, fish in a positive control group were given a feed treated with 20 mg kg-1 of 17β-oestradiol, and the control fish were given the feed free of either tested substance. The exposure of fish to propylparaben did not affect vitellogenesis after 20 days exposure but seemed to influence the sex differentiation processes, as evidenced by a sex ratio significantly skewed towards females in the group fed 500 mg kg-1 of propylparaben following 45 days of exposure. The potential of the fish to respond to oestrogenic stimulation was confirmed, since significantly higher vitellogenin concentrations were detected in the fish from the positive control group.

  10. Genetic analysis of male reproductive success in relation to density in the zebrafish, Danio rerio

    Jordan William C

    2006-04-01

    Full Text Available Abstract Background We used behavioural and genetic data to investigate the effects of density on male reproductive success in the zebrafish, Danio rerio. Based on previous measurements of aggression and courtship behaviour by territorial males, we predicted that they would sire more offspring than non-territorial males. Results Microsatellite analysis of paternity showed that at low densities territorial males had higher reproductive success than non-territorial males. However, at high density territorial males were no more successful than non-territorials and the sex difference in the opportunity for sexual selection, based on the parameter Imates, was low. Conclusion Male zebrafish exhibit two distinct mating tactics; territoriality and active pursuit of females. Male reproductive success is density dependent and the opportunity for sexual selection appears to be weak in this species.

  11. Oral exposure of adult zebrafish (Danio rerio) to 2,4,6-tribromophenol affects reproduction

    Halden, Anna Norman; Nyholm, Jenny Rattfelt; Andersson, Patrik L

    2010-01-01

    The bromophenol 2,4,6-tribromophenol (TBP) is widely used as an industrial chemical, formed by degradation of tetrabromobisphenol-A, and it occurs naturally in marine organisms. Concentrations of TBP in fish have been related to intake via feed, but little is known about effects on fish health...... after oral exposure. In this study, we exposed adult male and female zebrafish (Danio rerio) to TBP via feed in nominal concentrations of 33, 330, and 3300 mu g/g feed (or control feed) for 6 weeks to assess the effects of TBP on reproductive output, gonad morphology, circulatory vitellogenin levels......, and early embryo development. The aim was also to investigate the extent to which TBP was metabolised to 2,4,6-tribromoanisole (IBA) in dietary exposed zebrafish, and the amounts of TBP and TBA found in offspring. After 6 weeks of exposure, we found about 3% of the daily dose of TBP in adult fish...

  12. Genotoxic effects of boric acid and borax in zebrafish, Danio rerio using alkaline comet assay.

    Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P borax-induced genotoxicity in fish.

  13. Joint toxic effects of triazophos and imidacloprid on zebrafish (Danio rerio).

    Wu, Shenggan; Li, Xinfang; Liu, Xinju; Yang, Guiling; An, Xuehua; Wang, Qiang; Wang, Yanhua

    2018-04-01

    Pesticide contamination is more often found as a mixture of different pesticides in water bodies rather than individual compounds. However, regulatory risk evaluation is mostly based on the effects of individual pesticides. In the present study, we aimed to investigate the individual and joint toxicities of triazophos (TRI) and imidacloprid (IMI) to the zebrafish (Danio rerio) using acute indices and various sublethal endpoints. Results from 96-h semi-static test indicated that the LC 50 values of TRI to D. rerio at multiple life stages (embryonic, larval, juvenile and adult stages) ranged from 0.49 (0.36-0.71) to 4.99 (2.06-6.81) mg a.i. L -1 , which were higher than those of IMI ranging from 26.39 (19.04-38.01) to 128.9 (68.47-173.6) mg a.i. L -1 . Pesticide mixtures of TRI and IMI displayed synergistic response to zebrafish embryos. Activities of carboxylesterase (CarE) and catalase (CAT) were significantly changed in most of the individual and joint exposures of pesticides compared with the control group. The expressions of 26 genes related to oxidative stress, cellular apoptosis, immune system, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-gonadal axis at the mRNA level revealed that zebrafish embryos were affected by the individual or joint pesticides, and greater changes in the expressions of six genes (Mn-sod, CXCL-CIC, Dio1, Dio2, tsh and vtg1) were observed when exposed to joint pesticides compared with their individual pesticides. Taken together, the synergistic effects indicated that it was highly important to incorporate joint toxicity studies, especially at low concentrations, when assessing the risk of pesticides. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Developmental Toxicity Assay for Food Additive Tartrazine Using Zebrafish ( Danio rerio) Embryo Cultures.

    Joshi, Vani; Katti, Pancharatna

    Tartrazine (TTZ) is an azo dye used as a colorant in food products, drugs, and cosmetics. The present study evaluates the impacts of TTZ on embryonic development of zebrafish ( Danio rerio). Laboratory-raised D. rerio embryos (n = 20/concentration) were exposed to graded dilutions of TTZ (0, 0.1, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 75, and 100 mM) from gastrulation stage (5.25 hours postfertilization [hpf]) until hatching and developmental trajectory was traced up to day 7. The no observed effect concentration (NOEC), median lethal concentration (LC 50 ), median effective concentration (EC 50 ), and teratogenic index (TI) were calculated. Exposure of embryos to effects; 20 to 30 mM TTZ caused tail bending, cardiac and yolk sac edema in 50% of larvae; in 30 to 50 mM TTZ-exposed embryos the heart rates declined along with the above mentioned deformities, causing mortality within 96 to 144 hpf; development ceased completely at 75 to 100 mM concentration. The NOEC and LC 50 were recorded at 5 and 29.4 mM dose, respectively. The EC 50 values for heart rate, cardiac edema, tail bending, and hatching success were at 59.60, 53.81, 98.28, and 58.97 mM with TI quotient 0.49, 0.54, 0.29, and 0.49, respectively. We conclude that TTZ is not embryo toxic/teratogenic for zebrafish embryos up to a dose level of 10 mM concentration.

  15. Single and joint toxicity assessment of four currently used pesticides to zebrafish (Danio rerio) using traditional and molecular endpoints.

    Wang, Yanhua; Wu, Shenggan; Chen, Jine; Zhang, Changpeng; Xu, Zhenlan; Li, Gang; Cai, Leiming; Shen, Weifeng; Wang, Qiang

    2018-02-01

    Pesticides usually present in mixtures in surface waters, although they are traditionally regulated on an individual basis in aquatic ecosystems. In this study, we aimed to investigate the lethal and transcriptional responses of individual and combined pesticides (iprodione, pyrimethanil, pyraclostrobin and acetamiprid) on zebrafish (Danio rerio). Semi-static toxicity test indicated that the greatest toxicity to the four life stages (embryonic, larval, juvenile and adult stages) of D. rerio was detected from pyraclostrobin, followed by iprodione and pyrimethanil. In contrast, the lowest toxicity to the organisms was found from acetamiprid. Most of the selected pesticides exerted greater toxicities to D. rerio of embryonic stage compared with other life stages. Synergistic responses were observed from all binary mixtures of iprodione in combination with pyrimethanil or acetamiprid and ternary mixtures of iprodione+pyraclostrobin in combination with pyrimethanil or acetamiprid. The expressions of 16 genes related to cell apoptosis pathway, oxidative stress response, innate immunity and endocrine disruption at the mRNA level showed that zebrafish embryos were affected by the individual or combined pesticides. The expressions of P53, Tnf, TRβ, Tsh and Cyp19a exhibited greater changes upon exposure to combined pesticides compared with individual pesticides. Taken together, increased toxicity might be triggered by the simultaneous presence of several pesticides in the aquatic environment, which seriously damaged the non-target organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Chronic effects of clofibric acid in zebrafish (Danio rerio): A multigenerational study

    Coimbra, Ana M., E-mail: acoimbra@utad.pt [Centre for The Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real (Portugal); Department of Biology and Environment, Life Sciences and Environment School (ECVA), University of Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real (Portugal); Peixoto, Maria João [CIMAR/CIIMAR, Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Department of Biology and Environment, Life Sciences and Environment School (ECVA), University of Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real (Portugal); Coelho, Inês; Lacerda, Ricardo [CIMAR/CIIMAR, Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Carvalho, António Paulo [CIMAR/CIIMAR, Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); FCUP, Faculty of Sciences University of Porto, Department of Biology, Rua do Campo Alegre, 4169-007 Porto (Portugal); Gesto, Manuel [CIMAR/CIIMAR, Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); Department of Functional Biology and Health Sciences, Faculty of Biology, University of Vigo, As Lagoas-Marcosende s/n, 36310, Vigo (Spain); Lyssimachou, Angeliki; Lima, Daniela; Soares, Joana; André, Ana; Capitão, Ana [CIMAR/CIIMAR, Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Rua dos Bragas 177, 4050-123 Porto (Portugal); and others

    2015-03-15

    Highlights: • Clofibric acid (CA) induces multigenerational effects in zebrafish (Danio rerio). • CA impacts fish lipid metabolism, with similarities to those reported in mammals. • Weight is impacted in F1 and F2 generations, thought with opposite patterns. - Abstract: Clofibric acid (CA) is an active metabolite of the blood lipid lowering agent clofibrate, a pharmaceutical designed to work as agonist of peroxisome proliferator-activated receptor alpha (PPARa). It is the most commonly reported fibrate in aquatic environments with low degradation rate and potential environmental persistence. Previous fish exposures showed that CA may impact spermatogenesis, growth and the expression of fat binding protein genes. However, there are limited data on the effects of chronic multigenerational CA exposures. Here, we assessed chronic multigenerational effects of CA exposure using zebrafish (Danio rerio) as a teleost model. Zebrafish were exposed through the diet to CA (1 and 10 mg/g) during their whole lifetime. Growth, reproduction-related parameters and embryonic development were assessed in the exposed fish (F1 generation) and their offspring (F2 generation), together with muscle triglyceride content and gonad histology. In order to study the potential underlying mechanisms, the transcription levels of genes coding for enzymes involved in lipid metabolism pathways were determined. The results show that chronic life-cycle exposure to CA induced a significant reduction in growth of F1 generation and lowered triglyceride muscle content (10 mg/g group). Also, an impact in male gonad development was observed together with a decrease in the fecundity (10 mg/g group) and higher frequency of embryo abnormalities in the offspring of fish exposed to the lowest CA dose. The profile of the target genes was sex- and tissue-dependent. In F1 an up-regulation of male hepatic pparaa, pparb and acox transcript levels was observed, suggesting an activation of the fatty acid

  17. Chronic effects of clofibric acid in zebrafish (Danio rerio): A multigenerational study

    Coimbra, Ana M.; Peixoto, Maria João; Coelho, Inês; Lacerda, Ricardo; Carvalho, António Paulo; Gesto, Manuel; Lyssimachou, Angeliki; Lima, Daniela; Soares, Joana; André, Ana; Capitão, Ana

    2015-01-01

    Highlights: • Clofibric acid (CA) induces multigenerational effects in zebrafish (Danio rerio). • CA impacts fish lipid metabolism, with similarities to those reported in mammals. • Weight is impacted in F1 and F2 generations, thought with opposite patterns. - Abstract: Clofibric acid (CA) is an active metabolite of the blood lipid lowering agent clofibrate, a pharmaceutical designed to work as agonist of peroxisome proliferator-activated receptor alpha (PPARa). It is the most commonly reported fibrate in aquatic environments with low degradation rate and potential environmental persistence. Previous fish exposures showed that CA may impact spermatogenesis, growth and the expression of fat binding protein genes. However, there are limited data on the effects of chronic multigenerational CA exposures. Here, we assessed chronic multigenerational effects of CA exposure using zebrafish (Danio rerio) as a teleost model. Zebrafish were exposed through the diet to CA (1 and 10 mg/g) during their whole lifetime. Growth, reproduction-related parameters and embryonic development were assessed in the exposed fish (F1 generation) and their offspring (F2 generation), together with muscle triglyceride content and gonad histology. In order to study the potential underlying mechanisms, the transcription levels of genes coding for enzymes involved in lipid metabolism pathways were determined. The results show that chronic life-cycle exposure to CA induced a significant reduction in growth of F1 generation and lowered triglyceride muscle content (10 mg/g group). Also, an impact in male gonad development was observed together with a decrease in the fecundity (10 mg/g group) and higher frequency of embryo abnormalities in the offspring of fish exposed to the lowest CA dose. The profile of the target genes was sex- and tissue-dependent. In F1 an up-regulation of male hepatic pparaa, pparb and acox transcript levels was observed, suggesting an activation of the fatty acid

  18. Cadmium accumulation in zebrafish (Danio rerio) eggs is modulated by dissolved organic matter (DOM)

    Burnison, B. Kent; Meinelt, Thomas; Playle, Richard; Pietrock, Michael; Wienke, Andreas; Steinberg, Christian E.W.

    2006-01-01

    Experiments were conducted to investigate factors influencing the accumulation of cadmium (Cd 2+ ) into zebrafish (Danio rerio) eggs. The accumulation of 109 Cd was affected by: (1) concentration, (2) time, (3) presence of dissolved organic material (DOM), (4) different origin of DOM and (5) different parts of fish eggs. Over a 5-h exposure, zebrafish eggs showed a steady increase in Cd-accumulation. DOM-concentrations over 15 ppm carbon (C) decreased Cd-uptake significantly. Both samples of DOM, brown water marsh (LM) and a eutrophic pond (SP), at 16.9 ppm C, reduced the Cd-accumulation in the chorion, perivitelline liquid and the embryo. Cd was mainly accumulated in the egg's outer shell chorion (61%) and only small amounts passed through the chorion into the perivitelline liquid (38%) and embryo (1%). In the presence of LM-DOM, the accumulation of Cd into the egg components was decreased by 43% (chorion), 52% (perivitelline liquid) and 52% (embryo), respectively, compared with the control group. Similarly, the presence of SP-DOM reduced the Cd-accumulation by 29% (chorion), 61% (perivitelline liquid) and 60% (embryo), respectively, compared with the controls. DOM-concentration should be taken into consideration when determining ecotoxicological effects of Cd on fish populations

  19. Intrinsic Xenobiotic Metabolizing Enzyme Activities in Early Life Stages of Zebrafish (Danio rerio).

    Otte, Jens C; Schultz, Bernadette; Fruth, Daniela; Fabian, Eric; van Ravenzwaay, Bennard; Hidding, Björn; Salinas, Edward R

    2017-09-01

    Early life stages of zebrafish (Danio rerio, zf) are gaining attention as an alternative invivo test system for drug discovery, early developmental toxicity screenings and chemical testing in ecotoxicological and toxicological testing strategies. Previous studies have demonstrated transcriptional evidence for xenobiotic metabolizing enzymes (XME) during early zf development. However, elaborate experiments on XME activities during development are incomplete. In this work, the intrinsic activities of representative phase I and II XME were monitored by transformation of putative zf model substrates analyzed using photometry and high pressure liquid chromatography techniques. Six different defined stages of zf development (between 2.5 h postfertilization (hpf) to 120 hpf) were investigated by preparing a subcellular fraction from whole organism homogenates. We demonstrated that zf embryos as early as 2.5 hpf possess intrinsic metabolic activities for esterase, Aldh, Gst, and Cyp1a above the methodological detection limit. The activities of the enzymes Cyp3a and Nat were measurable during later stages in development. Activities represent dynamic patterns during development. The role of XME activities revealed in this work is relevant for the assessing toxicity in this test system and therefore contributes to a valuable characterization of zf embryos as an alternative testing organism in toxicology. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Food and conspecific chemical cues modify visual behavior of zebrafish, Danio rerio.

    Stephenson, Jessica F; Partridge, Julian C; Whitlock, Kathleen E

    2012-06-01

    Animals use the different qualities of olfactory and visual sensory information to make decisions. Ethological and electrophysiological evidence suggests that there is cross-modal priming between these sensory systems in fish. We present the first experimental study showing that ecologically relevant chemical mixtures alter visual behavior, using adult male and female zebrafish, Danio rerio. Neutral-density filters were used to attenuate the light reaching the tank to an initial light intensity of 2.3×10(16) photons/s/m2. Fish were exposed to food cue and to alarm cue. The light intensity was then increased by the removal of one layer of filter (nominal absorbance 0.3) every minute until, after 10 minutes, the light level was 15.5×10(16) photons/s/m2. Adult male and female zebrafish responded to a moving visual stimulus at lower light levels if they had been first exposed to food cue, or to conspecific alarm cue. These results suggest the need for more integrative studies of sensory biology.

  1. Expression of RPRM/rprm in the Olfactory System of Embryonic Zebrafish (Danio rerio)

    Stanic, Karen; Quiroz, Alonso; Lemus, Carmen G.; Wichmann, Ignacio A.; Corvalán, Alejandro H.; Owen, Gareth I.; Opazo, Juan C.; Concha, Miguel L.; Amigo, Julio D.

    2018-01-01

    The Reprimo (RPRM) family is composed of highly conserved single-exon genes. The expression pattern of this gene family has been recently described during zebrafish (Danio rerio) embryogenesis, and primarily locates in the nervous system. Its most characterized member, RPRM, which duplicated to give rise rprma and rprmb in the fish lineage, is known to act as a tumor-suppressor gene in mammalian models. Here, we describe in detail the spatiotemporal expression of three rprm genes (rprma, rprmb, and rprml) within distinct anatomical structures in the developing peripheral and central nervous system. In the zebrafish, rprma mRNA is expressed in the olfactory placodes (OP) and olfactory epithelium (OE), rprmb is observed in the tectum opticum (TeO) and trigeminal ganglion (Tg), whereas rprml is found primarily in the telencephalon (Tel). At protein level, RPRM is present in a subset of cells in the OP, and neurons in the OE, TeO, hindbrain and sensory peripheral structures. Most importantly, the expression of RPRM has been conserved between teleosts and mammals. Thus, we provide a reference dataset describing the expression patterns of RPRM gene products during zebrafish and mouse development as a first step to approach the physiological role of the RPRM gene family. PMID:29636669

  2. Methylmercury Induced Neurotoxicity and the Influence of Selenium in the Brains of Adult Zebrafish (Danio rerio

    Josef Daniel Rasinger

    2017-03-01

    Full Text Available The neurotoxicity of methylmercury (MeHg is well characterised, and the ameliorating effects of selenium have been described. However, little is known about the molecular mechanisms behind this contaminant-nutrient interaction. We investigated the influence of selenium (as selenomethionine, SeMet and MeHg on mercury accumulation and protein expression in the brain of adult zebrafish (Danio rerio. Fish were fed diets containing elevated levels of MeHg and/or SeMet in a 2 × 2 full factorial design for eight weeks. Mercury concentrations were highest in the brain tissue of MeHg-exposed fish compared to the controls, whereas lower levels of mercury were found in the brain of zebrafish fed both MeHg and SeMet compared with the fish fed MeHg alone. The expression levels of proteins associated with gap junction signalling, oxidative phosphorylation, and mitochondrial dysfunction were significantly (p < 0.05 altered in the brain of zebrafish after exposure to MeHg and SeMet alone or in combination. Analysis of upstream regulators indicated that these changes were linked to the mammalian target of rapamycin (mTOR pathways, which were activated by MeHg and inhibited by SeMet, possibly through a reactive oxygen species mediated differential activation of RICTOR, the rapamycin-insensitive binding partner of mTOR.

  3. Analytical developments for the speciation of uranium in zebra fish (Danio rerio) gills after exposure

    Bucher, Guillaume

    2013-01-01

    The objective of this thesis is to study the cellular compartmentalization and the chelation of uranium (U) by cytosolic proteins of gill cells of the zebra fish (Danio rerio, model specie in aquatic toxicology) under different direct exposure conditions (chronic vs. acute, 20 and 250 μg.L -1 ). This study required the development of hyphenated techniques (SEC, IEF off-gel, RP-UHPLC for the separation, ICP-SFMS, ESI-FTMS/MS for the detection) with the main challenges of maintaining the non-covalent U-biomolecule interactions and enhancing sensitivity for the analysis of environmentally relevant samples. After extraction, 24% to 32% of the total U detected in the gills were present in the cytosolic fraction, in which the U distribution on the biomolecules (as a function of their MW and pI) varied depending on the exposure level. Finally, U target biomolecules mapping allowed us (i) to highlight a particular affinity of U for acidic and/or P-containing proteins and (ii) to identify 24 protein candidates for U binding. (author) [fr

  4. Environmental estrogen(s) induced swimming behavioural alterations in adult zebrafish (Danio rerio).

    Goundadkar, Basavaraj B; Katti, Pancharatna

    2017-09-01

    The present study is an attempt to investigate the effects of long-term (75days) exposure to environmental estrogens (EE) on the swimming behaviour of zebrafish (Danio rerio). Adult zebrafish were exposed semi-statically to media containing commonly detected estrogenic water contaminants (EE2, DES and BPA) at a concentration (5ng/L) much lower than environmentally recorded levels. Time spent in swimming, surface preference, patterns and path of swimming were recorded (6mins) for each fish using two video cameras on day 15, 30 60 and 75. Video clips were analysed using a software program. Results indicate that chronic exposure to EE leads to increased body weight and size of females, reduced (Pswimming time, delay in latency, increased (P<0.05) immobility, erratic movements and freezing episodes. We conclude that estrogenic contamination of natural aquatic systems induces alterations in locomotor behaviour and associated physiological disturbances in inhabitant fish fauna. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Proteomic Signatures of the Zebrafish (Danio rerio) Embryo: Sensitivity and Specificity in Toxicity Assessment of Chemicals.

    Hanisch, Karen; Küster, Eberhard; Altenburger, Rolf; Gündel, Ulrike

    2010-01-01

    Studies using embryos of the zebrafish Danio rerio (DarT) instead of adult fish for characterising the (eco-) toxic potential of chemicals have been proposed as animal replacing methods. Effect analysis at the molecular level might enhance sensitivity, specificity, and predictive value of the embryonal studies. The present paper aimed to test the potential of toxicoproteomics with zebrafish eleutheroembryos for sensitive and specific toxicity assessment. 2-DE-based toxicoproteomics was performed applying low-dose (EC(10)) exposure for 48 h with three-model substances Rotenone, 4,6-dinitro-o-cresol (DNOC) and Diclofenac. By multivariate "pattern-only" PCA and univariate statistical analyses, alterations in the embryonal proteome were detectable in nonetheless visibly intact organisms and treatment with the three substances was distinguishable at the molecular level. Toxicoproteomics enabled the enhancement of sensitivity and specificity of the embryonal toxicity assay and bear the potency to identify protein markers serving as general stress markers and early diagnosis of toxic stress.

  6. Changes in Neurotransmitter Profiles during Early Zebrafish (Danio rerio) Development and after Pesticide Exposure.

    Tufi, Sara; Leonards, Pim; Lamoree, Marja; de Boer, Jacob; Legler, Juliette; Legradi, Jessica

    2016-03-15

    During early development, neurotransmitters are important stimulants for the development of the central nervous system. Although the development of different neuronal cell types during early zebrafish (Danio rerio) development is well-studied, little is known of the levels of neurotransmitters, their precursors and metabolites during development, and how these levels are affected by exposure to environmental contaminants. A method based on hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry has been applied for the first time to zebrafish embryos and larvae to study five neurotransmitter systems in parallel, including the dopaminergic-andrenergic, glutaminergic-GABAnergic, serotoninergic, histaminergic, and cholinergic systems. Our method enables the quantification of neurotransmitters and their precursors and metabolites in whole zebrafish from the period of zygote to free-swimming larvae 6 days postfertilization (dpf). We observed a developmental stage-dependent pattern with clear differences between the first 2 days of development and the following days. Whereas the neurotransmitter levels steadily increased, the precursors showed a peak at 3 dpf. After exposure to several pesticides, significant differences in concentrations of neurotransmitters and precursors were observed. Our study revealed new insights about neurotransmitter systems during early zebrafish development and showed the usefulness of our approach for environmental neurotoxicity studies.

  7. Embryotoxicity and genotoxicity evaluation of sediments from Yangtze River estuary using zebrafish (Danio rerio) embryos.

    Li, Qian; Chen, Ling; Liu, Li; Wu, Lingling

    2016-03-01

    Sediments function both as a sink and a source of pollutants in aquatic ecosystems and may impose serious effects on benthic organisms and human health. As one of the largest estuaries in the world, the Yangtze River estuary suffers from abundant wastewater from the coastal cities. In this study, the zebrafish (Danio rerio) embryos were employed in the fish embryo test and a comet assay to evaluate the embryotoxicity and genotoxicity of the sediments from the Yangtze River estuary, respectively. Results showed that the sediments from the Yangtze River estuary significantly increased mortality, induced development abnormalities, and reduced hatching rate and heart rate of zebrafish embryos after 96 h of exposure. Significant genotoxicity was observed in the samples relative to the controls. Relatively low-level embryotoxicity and genotoxicity of sediments were found in the Yangtze River compared with other river systems. Toxic responses were also discussed in relation to the analyzed organic contaminants in sediments. More attention should be paid to non-priority pollutant monitoring in the Yangtze River estuary.

  8. Cardiac and Metabolic Physiology of Early Larval Zebrafish (Danio rerio) Reflects Parental Swimming Stamina.

    Gore, Matthew; Burggren, Warren W

    2012-01-01

    Swimming stamina in adult fish is heritable, it is unknown if inherited traits that support enhanced swimming stamina in offspring appear only in juveniles and/or adults, or if these traits actually appear earlier in the morphologically quite different larvae. To answer this question, mature adult zebrafish (Danio rerio) were subjected to a swimming performance test that allowed separation into low swimming stamina or high swimming stamina groups. Adults were then bred within their own performance groups. Larval offspring from each of the two groups, designated high (L(HSD)) and low stamina-derived larvae (L(LSD)), were then reared at 27°C in aerated water (21% O(2)). Routine (f(H),r) and active (f(H),a) heart rate, and routine [Formula: see text] and active [Formula: see text] mass-specific oxygen consumption were recorded from 5 days post fertilization (dpf) through 21 dpf, and gross cost of transport and factorial aerobic metabolic scope were derived from [Formula: see text] measurements. Heart rate generally ranged between 150 and 225 bpm in both L(HSD) and L(LSD) populations. However, significant (P stamina in adult parents also appear in their larval offspring well before attainment of juvenile or adult features.

  9. Tributyltin promoted hepatic steatosis in zebrafish (Danio rerio) and the molecular pathogenesis involved.

    Zhang, Jiliang; Sun, Ping; Kong, Tao; Yang, Fan; Guan, Wenchao

    2016-01-01

    Endocrine disruptor effects of tributyltin (TBT) are well established in fish. However, the adverse effects on lipid metabolism are less well understood. Since the liver is the predominant site of de novo synthesis of lipids, the present study uses zebrafish (Danio rerio) to examine lipid accumulation in the livers and hepatic gene expression associated with lipid metabolism pathways. After exposure for 90 days, we found that the livers in fish exposed to TBT were yellowish in appearance and with accumulation of lipid droplet, which is consistent with the specific pathological features of steatosis. Molecular analysis revealed that TBT induced hepatic steatosis by increasing the gene expression associated with lipid transport, lipid storage, lipiogenic enzymes and lipiogenic factors in the livers. Moreover, TBT enhanced hepatic caspase-3 activity and up-regulated genes related to apoptosis and cell-death, which indicated steatotic livers of fish exposed to TBT and the subsequent liver damage were likely due to accelerated hepatocyte apoptosis or cell stress. In short, TBT can produce multiple and complex alterations in transcriptional activity of lipid metabolism and cell damage, which provides potential molecular evidence of TBT on hepatic steatosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Effect of tributyltin on antioxidant ability and immune responses of zebrafish (Danio rerio).

    Zhang, Chun-Nuan; Zhang, Ji-Liang; Ren, Hong-Tao; Zhou, Bian-Hua; Wu, Qiu-Jue; Sun, Ping

    2017-04-01

    Tributyltin (TBT) is a toxic compound released into aquatic ecosystems through antifouling paints. This study was designed to examine the effects of TBT on antioxidant ability and immune responses of zebrafish (Danio rerio). Three hundred sixty healthy zebrafish were randomly grouped into four groups and exposed to different doses of TBT (0, 1, 10 and 100ngL -1 ). At the end of 8 weeks, the fish were sampled, and antioxidant capability, immune parameters and immune-related genes were assessed. The results showed that with an increase in TBT dose, the concentration of malonaldehyde in the liver was significantly increased (p<0.05), whereas the activities of total superoxide dismutase, catalase and glutathione peroxidase were significantly decreased (p<0.05) compared to the control. The activity and expression of lysozyme and the content of immunoglobulin M were significantly decreased compared to those of the fish exposed to 0ngL -1 TBT (p<0.05). However, the expression of the HSP70, HSP90, tumor necrosis factor-α(TNF-α), interleukins (IL-1β, IL-6), and nuclear factor-kappa B p65 (NF-κ B p65) genes were all enhanced with an increase in TBT dose. The results indicated that TBT induced oxidative stress and had immunotoxic effects on zebrafish. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. In Vivo Toxicity of Silver Nanoparticles and Silver Ions in Zebrafish (Danio rerio

    Katrine Bilberg

    2012-01-01

    Full Text Available The influence of water chemistry on characterised polyvinyl pyrrolidone- (PVP- coated silver nanoparticles (81 nm was investigated. NaCl solution series of 100–800 mg L−1 lead to initial and temporal increase in nanoparticles size, but agglomeration was limited. pH variation (5–8 had only minor influence on the hydrodynamic particle size. Acute toxicity of nanosivler to zebrafish (Danio rerio was investigated in a 48-hour static renewal study and compared with the toxicity of silver ions (AgNO3. The nanosilver and silver ion 48-hour median lethal concentration (LC50 values were 84 μg L−1 and 25 μg L−1, respectively. To investigate exposure-related stress, the fish behaviour was observed visually after 0, 3, 6, 12, 24, 27, 30, and 48 hours of both nanosilver and ionic silver treatments. These observations revealed increased rate of operculum movement and surface respiration after nanosilver exposure, suggesting respiratory toxicity. The present study demonstrates that silver nanoparticles are lethal to zebrafish.

  12. Estrogenic effect of the phytoestrogen biochanin A in zebrafish, Danio rerio, and brown trout, Salmo trutta.

    Holbech, Henrik; Schröder, Kristoffer D; Nielsen, Marie L; Brande-Lavridsen, Nanna; Holbech, Bente Frost; Bjerregaard, Poul

    2013-11-15

    Isoflavones with estrogenic activity produced in Fabaceae plants are known to leach from agricultural areas to freshwater systems, but the effect of waterborne isoflavones in fish has not been thoroughly characterized. Therefore, the estrogenic effect of waterborne biochanin A was investigated in zebrafish (Danio rerio) and juvenile brown trout (Salmo trutta). Exposure of juvenile brown trout to 10 μg biochanin AL(-1) or higher caused marked vitellogenin induction after 9-10 days of exposure and so did exposure to 186 μg biochanin AL(-1) for 6h. Following 8d of exposure, a NOEC for induction of vitellogenin production in male zebrafish was 70 and LOEC 114 μg biochanin AL(-1). Exposure to 209 μg biochanin AL(-1) from hatch to 60 days post hatch (dph) caused a skewing of the sex ratio toward more phenotypic female zebrafish, but did not cause induction of vitellogenin in male and undifferentiated fish. (1) biochanin A elicits estrogenic effects in trout at environmentally realistic concentrations, (2) brown trout plasma vitellogenin concentrations respond to lower biochanin A exposure concentrations than vitellogenin concentrations in zebrafish homogenates and (3) concerning vitellogenin induction, the hypothesis should be tested if short term tests with zebrafish may show a higher sensitivity than partial life cycle tests. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Combined effects of silver nanoparticles and mercury on gill histopathology of zebrafish (Danio rerio

    Borhan Mansouri

    2016-06-01

    Full Text Available Objective: To evaluate the combined effects of silver nanoparticles (Ag NPs and Hg2+ on the gill histopathology of zebrafish (Danio rerio under the controlled conditions. Methods: In this study, one non-lethal concentration of Ag NPs (0.1 mg/L, six concentrations of Hg2+ (0.001, 0.005, 0.01, 0.05, 0.1 and 0.2 mg/L, and six mixture concentrations of Ag NPs and Hg2+ (0.1 plus 0.001, 0.005, 0.01, 0.05, 0.1, and 0.2 mg/L were used as the control group. After 4 days of exposure, samples were prepared for gill histology. Results: The results showed that notable damages were observed in aneurism, such as vacuolation of secondary lamella, fusion, hypertrophy, mucus secretion and necrosis. Moreover, our findings indicated that the Hg2+ and Ag NPs alone led to shorter secondary lamella length and smaller lamellae’s diameter of gills compared to the mixture of Ag NPs and Hg2+. However, the extent of damages in gill tissues after exposure to mixture of Ag NPs and Hg2+ was lower than Hg2+ ions and Ag NPs. Conclusions: It appears that the presence of Ag NPs can potentially reduce the toxicity of Hg2+ ions. However, to assess the toxicity mechanisms of nanoparticles in presence of pollutants, further studies should be encouraged.

  14. From schooling to shoaling: patterns of collective motion in zebrafish (Danio rerio.

    Noam Miller

    Full Text Available Animal groups on the move can take different configurations. For example, groups of fish can either be 'shoals' or 'schools': shoals are simply aggregations of individuals; schools are shoals exhibiting polarized, synchronized motion. Here we demonstrate that polarization distributions of groups of zebrafish (Danio rerio are bimodal, showing two distinct modes of collective motion corresponding to the definitions of shoaling and schooling. Other features of the group's motion also vary consistently between the two modes: zebrafish schools are faster and less dense than zebrafish shoals. Habituation to an environment can also alter the proportion of time zebrafish groups spend schooling or shoaling. Models of collective motion suggest that the degree and stability of group polarization increases with the group's density. Examining zebrafish groups of different sizes from 5 to 50, we show that larger groups are less polarized than smaller groups. Decreased fearfulness in larger groups may function similarly to habituation, causing them to spend more time shoaling than schooling, contrary to most models' predictions.

  15. Expression of RPRM/rprm in the Olfactory System of Embryonic Zebrafish (Danio rerio

    Karen Stanic

    2018-03-01

    Full Text Available The Reprimo (RPRM family is composed of highly conserved single-exon genes. The expression pattern of this gene family has been recently described during zebrafish (Danio rerio embryogenesis, and primarily locates in the nervous system. Its most characterized member, RPRM, which duplicated to give rise rprma and rprmb in the fish lineage, is known to act as a tumor-suppressor gene in mammalian models. Here, we describe in detail the spatiotemporal expression of three rprm genes (rprma, rprmb, and rprml within distinct anatomical structures in the developing peripheral and central nervous system. In the zebrafish, rprma mRNA is expressed in the olfactory placodes (OP and olfactory epithelium (OE, rprmb is observed in the tectum opticum (TeO and trigeminal ganglion (Tg, whereas rprml is found primarily in the telencephalon (Tel. At protein level, RPRM is present in a subset of cells in the OP, and neurons in the OE, TeO, hindbrain and sensory peripheral structures. Most importantly, the expression of RPRM has been conserved between teleosts and mammals. Thus, we provide a reference dataset describing the expression patterns of RPRM gene products during zebrafish and mouse development as a first step to approach the physiological role of the RPRM gene family.

  16. Gene expression profiling of the androgen receptor antagonists flutamide and vinclozolin in zebrafish (Danio rerio) gonads

    Martinovic-Weigelt, Dalma; Wang Ronglin; Villeneuve, Daniel L.; Bencic, David C.; Lazorchak, Jim; Ankley, Gerald T.

    2011-01-01

    The studies presented in this manuscript focus on characterization of transcriptomic responses to anti-androgens in zebrafish (Danio rerio). Research on the effects of anti-androgens in fish has been characterized by a heavy reliance on apical endpoints, and molecular mechanisms of action (MOA) of anti-androgens remain poorly elucidated. In the present study, we examined effects of a short term exposure (24-96 h) to the androgen receptor antagonists flutamide (FLU) and vinclozolin (VZ) on gene expression in gonads of sexually mature zebrafish, using commercially available zebrafish oligonucleotide microarrays (4 x 44 K platform). We found that VZ and FLU potentially impact reproductive processes via multiple pathways related to steroidogenesis, spermatogenesis, and fertilization. Observed changes in gene expression often were shared by VZ and FLU, as demonstrated by overlap in differentially-expressed genes and enrichment of several common key pathways including: (1) integrin and actin signaling, (2) nuclear receptor 5A1 signaling, (3) fibroblast growth factor receptor signaling, (4) polyamine synthesis, and (5) androgen synthesis. This information should prove useful to elucidating specific mechanisms of reproductive effects of anti-androgens in fish, as well as developing biomarkers for this important class of endocrine-active chemicals.

  17. Functional behavior and reproduction in androgenic sex reversed zebrafish (Danio rerio).

    Larsen, Mia G; Baatrup, Erik

    2010-08-01

    Endocrine-disrupting chemicals released into natural watercourses may cause biased sex ratios by sex reversal in fish populations. The present study investigated the androgenic sex reversal of zebrafish (Danio rerio) exposed to the androgenic compound 17beta-trenbolone (TB) and whether sex-changed females would revert to the female phenotype after cessation of TB exposure. 17beta-Trenbolone is a metabolite of trenbolone acetate, an anabolic steroid used as a growth promoter in beef cattle. 17beta-Trenbolone in runoff from cattle feedlots may reach concentrations that affect fish sexual development. Zebrafish were exposed to a concentration of 20 ng/L TB in a flow-through system for five months from egg until sexual maturity. This resulted in an all-male population. It was further found that all these phenotypic males displayed normal male courtship behavior and were able to reproduce successfully, implying that the sex reversal was complete and functional. None of the phenotypic males developed into females after six months in clean water, demonstrating that androgenic sex reversal of zebrafish is irreversible. Copyright 2010 SETAC

  18. Long-term (30 days toxicity of NiO nanoparticles for adult zebrafish Danio rerio

    Kovrižnych Jevgenij A.

    2014-03-01

    Full Text Available Nickel oxide in the form of nanoparticles (NiO NPs is extensively used in different industrial branches. In a test on adult zebrafish, the acute toxicity of NiO NPs was shown to be low, however longlasting contact with this compound can lead to its accumulation in the tissues and to increased toxicity. In this work we determined the 30-day toxicity of NiO NPs using a static test for zebrafish Danio rerio. We found the 30-day LC50 value to be 45.0 mg/L, LC100 (minimum concentration causing 100% mortality was 100.0 mg/L, and LC0 (maximum concentration causing no mortality was 6.25 mg/L for adult individuals of zebrafish. Considering a broad use of Ni in the industry, NiO NPs chronic toxicity may have a negative impact on the population of aquatic organisms and on food web dynamics in aquatic systems.

  19. The Effect of Water Hardness on Mortality of Zebrafish (Danio rerio) During Exposure to Oxytetracycline.

    Hundt, Matthias; Schreiber, Benjamin; Eckmann, Reiner; Lunestad, Bjørn Tore; Wünneman, Hannah; Schulz, Ralf

    2016-02-01

    Marking of fish otoliths with oxytetracycline and tetracycline is a widely used method to evaluate the effectiveness of stocking operations. Available protocols for the labeling of fish specify a number of factors influencing mark quality and potential risk for fish during marking. This study investigates the influence of water hardness on mortality of freshwater fish during marking with OTC. In order to pursue this question complexation of OTC with Mg(2+) and Ca(2+) cations was measured spectrophotometrically. Furthermore, zebrafish (Danio rerio) were immersed in OTC solutions (1200 mg/L; 48 h immersion) combined with varying levels of water hardness (5.5, 15.5, 25.5, 32.5°dH). The amount of OTC-Mg-Ca-complexes was positively correlated to water hardness. Moreover, it could be demonstrated that mortality of zebrafish during marking varied as a factor of water hardness. Highest mortalities occurred at the lowest (5.5°dH) and the highest (32.5°dH) tested levels during marking with OTC.

  20. Husbandry stress exacerbates mycobacterial infections in adult zebrafish, Danio rerio (Hamilton)

    Ramsay, J.M.; Watral, Virginia G.; Schreck, C.B.; Kent, M.L.

    2009-01-01

    Mycobacteria are significant pathogens of laboratory zebrafish, Danio rerio (Hamilton). Stress is often implicated in clinical disease and morbidity associated with mycobacterial infections but has yet to be examined with zebrafish. The aim of this study was to examine the effects of husbandry stressors on zebrafish infected with mycobacteria. Adult zebrafish were exposed to Mycobacterium marinum or Mycobacterium chelonae, two species that have been associated with disease in zebrafish. Infected fish and controls were then subjected to chronic crowding and handling stressors and examined over an 8-week period. Whole-body cortisol was significantly elevated in stressed fish compared to non-stressed fish. Fish infected with M. marinum ATCC 927 and subjected to husbandry stressors had 14% cumulative mortality while no mortality occurred among infected fish not subjected to husbandry stressors. Stressed fish, infected with M. chelonae H1E2 from zebrafish, were 15-fold more likely to be infected than non-stressed fish at week 8 post-injection. Sub-acute, diffuse infections were more common among stressed fish infected with M. marinum or M. chelonae than non-stressed fish. This is the first study to demonstrate an effect of stress and elevated cortisol on the morbidity, prevalence, clinical disease and histological presentation associated with mycobacterial infections in zebrafish. Minimizing husbandry stress may be effective at reducing the severity of outbreaks of clinical mycobacteriosis in zebrafish facilities. ?? 2009 Blackwell Publishing Ltd.

  1. Probiotic supplementation promotes calcification in Danio rerio larvae: a molecular study.

    Francesca Maradonna

    Full Text Available A growing number of studies have been showing that dietary probiotics can exert beneficial health effects in both humans and animals. We previously demonstrated that dietary supplementation with Lactobacillus rhamnosus - a component of the human gut microflora - enhances reproduction, larval development, and the biomineralization process in Danio rerio (zebrafish. The aim of this study was to identify the pathways affected by L. rhamnosus during zebrafish larval development. Our morphological and histochemical findings show that L. rhamnosus accelerates bone deposition through stimulation of the expression of key genes involved in ossification, e.g. runt-related transcription factor 2 (runx2, Sp7 transcription factor (sp7, matrix Gla protein (mgp, and bone gamma-carboxyglutamate (gla protein (bglap as well as through inhibition of sclerostin (sost, a bone formation inhibitor. Western blot analysis of mitogen-activated protein kinase 1 and 3-(Mapk1 and Mapk3, which are involved in osteoblast and osteocyte differentiation, documented an increase in Mapk1 16 days post fertilization (dpf and of Mapk3 23 dpf in individuals receiving L. rhamnosus supplementation. Interestingly, a reduction of sost detected in the same individuals suggests that the probiotic may help treat bone disorders.

  2. Acute toxicity and gene responses induced by endosulfan in zebrafish (Danio rerio embryos

    Young-Sun Moon

    2016-10-01

    Full Text Available Endosulfan has been listed as a persistent organic pollutant, and is frequently found in agricultural environments during monitoring processes owing to its heavy use and persistent characteristics. This study was conducted to understand the effects of endosulfan on the development of zebrafish (Danio rerio embryos by exposing them to a specific range of endosulfan concentrations. Exposing zebrafish embryos to endosulfan for 96 h yielded no acute toxicity until the concentration reached 1500 μg L−1, whereas malformed zebrafish larvae developed severely curved spines and shortened tails. About 50% of zebrafish larvae were malformed when exposed to 600 μg L−1 of endosulfan. Comparative gene expression using real-time quantitative polymerase chain reaction was assessed using endosulfan-exposed zebrafish embryos. CYP1A and CYP3A were significantly enhanced in response to endosulfan treatment. Two genes, acacb and fasn, encoding acetyl-CoA carboxylase b and fatty acid synthase proteins, respectively, were also up-regulated after treating zebrafish embryos with endosulfan. These genes are also involved in fatty acid biosynthesis. The genes encoding vitellogenin and Hsp70 increased in a concentration-dependent manner in embryos. Finally, biochemical studies showed that acetylcholinesterase activity was reduced, whereas glutathione S-transferase and carboxylesterase activities were enhanced in zebrafish embryos after endosulfan treatment. These biochemical and molecular biological differences might be used for tools to determine contamination of endosulfan in the aquatic environment.

  3. Ingestion of metal-nanoparticle contaminated food disrupts endogenous microbiota in zebrafish (Danio rerio)

    Merrifield, Daniel L.; Shaw, Benjamin J.; Harper, Glenn M.; Saoud, Imad P.; Davies, Simon J.; Handy, Richard D.; Henry, Theodore B.

    2013-01-01

    Nanoparticles (NPs) can be ingested by organisms, and NPs with antimicrobial properties may disrupt beneficial endogenous microbial communities and affect organism health. Zebrafish were fed diets containing Cu-NPs or Ag-NPs (500 mg kg −1 food), or an appropriate control for 14 d. Intestinal epithelium integrity was examined by transmission electron microscopy, and microbial community structure within the intestine was assessed by denaturing gradient gel electrophoresis (DGGE) of partial 16S rRNA. No lesions were observed in intestinal epithelia; however, presence of NPs in diets changed intestinal microbial community structure. In particular, some beneficial bacterial strains (e.g., Cetobacterium somerae) were suppressed to non-detectable levels by Cu-NP exposure, and two unidentified bacterial clones from the Firmicutes phylum were sensitive (not detected) to Cu, but were present in Ag and control fish. Unique changes in zebrafish microbiome caused by exposure to Ag-NP and Cu-NP indicate that NP ingestion could affect digestive system function and organism health. -- Highlights: ► Zebrafish ingest Cu- and Ag-nanoparticles (NPs) in diet. ► No effect of Cu-NPs or Ag-NPs on intestinal epithelial integrity. ► Cu-NPs and Ag-NPs alter endogenous microbiota of zebrafish. -- Dietary exposure to manufactured Cu- and Ag-nanoparticles caused unique changes in endogenous gut microbiota in zebrafish Danio rerio

  4. Gene expression profiling of the androgen receptor antagonists flutamide and vinclozolin in zebrafish (Danio rerio) gonads.

    Martinović-Weigelt, Dalma; Wang, Rong-Lin; Villeneuve, Daniel L; Bencic, David C; Lazorchak, Jim; Ankley, Gerald T

    2011-01-25

    The studies presented in this manuscript focus on characterization of transcriptomic responses to anti-androgens in zebrafish (Danio rerio). Research on the effects of anti-androgens in fish has been characterized by a heavy reliance on apical endpoints, and molecular mechanisms of action (MOA) of anti-androgens remain poorly elucidated. In the present study, we examined effects of a short term exposure (24-96h) to the androgen receptor antagonists flutamide (FLU) and vinclozolin (VZ) on gene expression in gonads of sexually mature zebrafish, using commercially available zebrafish oligonucleotide microarrays (4×44K platform). We found that VZ and FLU potentially impact reproductive processes via multiple pathways related to steroidogenesis, spermatogenesis, and fertilization. Observed changes in gene expression often were shared by VZ and FLU, as demonstrated by overlap in differentially-expressed genes and enrichment of several common key pathways including: (1) integrin and actin signaling, (2) nuclear receptor 5A1 signaling, (3) fibroblast growth factor receptor signaling, (4) polyamine synthesis, and (5) androgen synthesis. This information should prove useful to elucidating specific mechanisms of reproductive effects of anti-androgens in fish, as well as developing biomarkers for this important class of endocrine-active chemicals. 2010 Elsevier B.V. All rights reserved.

  5. Ingestion of metal-nanoparticle contaminated food disrupts endogenous microbiota in zebrafish (Danio rerio)

    Merrifield, Daniel L.; Shaw, Benjamin J.; Harper, Glenn M. [School of Biomedical and Biological Sciences, Plymouth University, 401 Davy Building, Drake Circus, Plymouth PL4 8AA, Devon (United Kingdom); Saoud, Imad P. [American University of Beirut, Beirut (Lebanon); Davies, Simon J.; Handy, Richard D. [School of Biomedical and Biological Sciences, Plymouth University, 401 Davy Building, Drake Circus, Plymouth PL4 8AA, Devon (United Kingdom); Henry, Theodore B., E-mail: ted.henry@plymouth.ac.uk [School of Biomedical and Biological Sciences, Plymouth University, 401 Davy Building, Drake Circus, Plymouth PL4 8AA, Devon (United Kingdom); Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN (United States); Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN (United States)

    2013-03-15

    Nanoparticles (NPs) can be ingested by organisms, and NPs with antimicrobial properties may disrupt beneficial endogenous microbial communities and affect organism health. Zebrafish were fed diets containing Cu-NPs or Ag-NPs (500 mg kg{sup −1} food), or an appropriate control for 14 d. Intestinal epithelium integrity was examined by transmission electron microscopy, and microbial community structure within the intestine was assessed by denaturing gradient gel electrophoresis (DGGE) of partial 16S rRNA. No lesions were observed in intestinal epithelia; however, presence of NPs in diets changed intestinal microbial community structure. In particular, some beneficial bacterial strains (e.g., Cetobacterium somerae) were suppressed to non-detectable levels by Cu-NP exposure, and two unidentified bacterial clones from the Firmicutes phylum were sensitive (not detected) to Cu, but were present in Ag and control fish. Unique changes in zebrafish microbiome caused by exposure to Ag-NP and Cu-NP indicate that NP ingestion could affect digestive system function and organism health. -- Highlights: ► Zebrafish ingest Cu- and Ag-nanoparticles (NPs) in diet. ► No effect of Cu-NPs or Ag-NPs on intestinal epithelial integrity. ► Cu-NPs and Ag-NPs alter endogenous microbiota of zebrafish. -- Dietary exposure to manufactured Cu- and Ag-nanoparticles caused unique changes in endogenous gut microbiota in zebrafish Danio rerio.

  6. Exposure of juvenile Danio rerio to aged TiO₂ nanomaterial from sunscreen.

    Fouqueray, Manuela; Noury, Patrice; Dherret, Lysiane; Chaurand, Perrine; Abbaci, Khedidja; Labille, Jerome; Rose, Jerome; Garric, Jeanne

    2013-05-01

    The toxicity of dietary exposure to artificially aged TiO₂ nanomaterial (T-Lite) used in sunscreen cream was studied on Danio rerio. Embryolarval assays were conducted to assess the effects of TiO₂ residues of nanomaterial (RNM) on fish early life stages. Juvenile fishes were exposed by the trophic route in two experiments. During the first experiment, juvenile fishes were exposed to TiO₂ RNM for 14 days by adding RNM to commercial fish food. The second one consisted in producing a trophic food chain. Pseudokirchneriella subcapitata algae, previously contaminated with TiO₂ RNM in growth medium, was used to feed Daphnia magna neonates over a 48-h period. Daphnia were used next to feed juvenile fishes for 7 days. Accumulation of Ti, life traits (survival and growth) and biochemical parameters such as energy reserves, digestive (trypsin, esterase, cellulose and amylase) and antioxidant (superoxide dismutase and catalase) enzyme activity were measured at the end of exposures. As expected in the receiving aquatic system, TiO2 RNM at low concentrations caused a low impact on juvenile zebrafish. A slight impact on the early life stage of zebrafish with premature hatching was observed, and this effect appeared mainly indirect, due to possible embryo hypoxia. When juvenile fish are exposed to contaminated food, digestive enzyme activity indicated a negative effect of TiO₂ RNM. Digestive physiology was altered after 14 days of exposure and seemed to be an indirect target of TiO₂ RNM when provided by food.

  7. Gene expression profiling of the androgen receptor antagonists flutamide and vinclozolin in zebrafish (Danio rerio) gonads

    Martinovic-Weigelt, Dalma, E-mail: dalma@stthomas.edu [US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804 (United States); University of St. Thomas, 2115 Summit Ave, Saint Paul, MN 55105 (United States); Wang Ronglin [US Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Ecological Exposure Research Division, 26W. Martin Luther King Dr., Cincinnati, OH 45268 (United States); Villeneuve, Daniel L. [US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804 (United States); Bencic, David C.; Lazorchak, Jim [US Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Ecological Exposure Research Division, 26W. Martin Luther King Dr., Cincinnati, OH 45268 (United States); Ankley, Gerald T. [US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd., Duluth, MN 55804 (United States)

    2011-01-25

    The studies presented in this manuscript focus on characterization of transcriptomic responses to anti-androgens in zebrafish (Danio rerio). Research on the effects of anti-androgens in fish has been characterized by a heavy reliance on apical endpoints, and molecular mechanisms of action (MOA) of anti-androgens remain poorly elucidated. In the present study, we examined effects of a short term exposure (24-96 h) to the androgen receptor antagonists flutamide (FLU) and vinclozolin (VZ) on gene expression in gonads of sexually mature zebrafish, using commercially available zebrafish oligonucleotide microarrays (4 x 44 K platform). We found that VZ and FLU potentially impact reproductive processes via multiple pathways related to steroidogenesis, spermatogenesis, and fertilization. Observed changes in gene expression often were shared by VZ and FLU, as demonstrated by overlap in differentially-expressed genes and enrichment of several common key pathways including: (1) integrin and actin signaling, (2) nuclear receptor 5A1 signaling, (3) fibroblast growth factor receptor signaling, (4) polyamine synthesis, and (5) androgen synthesis. This information should prove useful to elucidating specific mechanisms of reproductive effects of anti-androgens in fish, as well as developing biomarkers for this important class of endocrine-active chemicals.

  8. Sleep deprivation effects on object discrimination task in zebrafish (Danio rerio).

    Pinheiro-da-Silva, Jaquelinne; Silva, Priscila Fernandes; Nogueira, Marcelo Borges; Luchiari, Ana Carolina

    2017-03-01

    The zebrafish is an ideal vertebrate model for neurobehavioral studies with translational relevance to humans. Many aspects of sleep have been studied, but we still do not understand how and why sleep deprivation alters behavioral and physiological processes. A number of hypotheses suggest its role in memory consolidation. In this respect, the aim of this study was to analyze the effects of sleep deprivation on memory in zebrafish (Danio rerio), using an object discrimination paradigm. Four treatments were tested: control, partial sleep deprivation, total sleep deprivation by light pulses, and total sleep deprivation by extended light. The control group explored the new object more than the known object, indicating clear discrimination. The partially sleep-deprived group explored the new object more than the other object in the discrimination phase, suggesting a certain degree of discriminative performance. By contrast, both total sleep deprivation groups equally explored all objects, regardless of their novelty. It seems that only one night of sleep deprivation is enough to affect discriminative response in zebrafish, indicating its negative impact on cognitive processes. We suggest that this study could be a useful screening tool for cognitive dysfunction and a better understanding of the effect of sleep-wake cycles on cognition.

  9. Efficacy of cleaning and disinfection procedures in a zebrafish (Danio rerio) facility.

    Garcia, Rachel L; Sanders, George E

    2011-11-01

    Appropriate cleaning and disinfection procedures in zebrafish (Danio rerio) laboratories are crucial in preventing the spread of aquatic animal pathogens and minimizing the build-up of waste products and biologic matter. The procedures selected should accomplish these goals and incorporate the individual needs of various laboratories. In this study of a single zebrafish facility, we assessed the efficacy of 2 different cleaning and disinfection procedures for nets, tanks, and lids. ATP levels were used as a surrogate biomarker for microbial burden. We measured the number of relative light units (RLU), as an expression of the amount of ATP present, on items before and after disinfection and calculated the percentage reduction. We compared daily replacement of a commercial net disinfection product in J lab with weekly replacement in H lab and found a 96.6% reduction in RLU in H lab and a 91.2% reduction in J lab. These results indicate that either replacement schedule is effective. Evaluation of tanks and lids soaked in a bleach disinfection bath for 30 or 60 min revealed a 99.7% reduction in RLU at 30 min compared with 97.1% at 60 min. Therefore a 30-min soak in a bleach bath achieved a similar level of disinfection as did a 60-min soak. The current results demonstrate that these cleaning and disinfection methods are efficacious.

  10. Effects of aqueous stable fullerene nanocrystals (nC60) on the food conversion from Daphnia magna to Danio rerio in a simplified freshwater food chain.

    Tao, Xianji; Li, Cuilan; Zhang, Bo; He, Yiliang

    2016-02-01

    Understanding the nanomaterial potential to the food conversion of two food chain levels is important in the ecosystem assessment as manufactured nanomaterials are being released into the environment. In this investigation, the food conversion from Daphnia magna (D. magna) (prey) to Danio rerio (D. rerio) (predator) was used as the study object of aqueous stable fullerene nanocrystals (nC60). Accumulated nC60 of D. magna was determined as the nominal initial exposure concentration for D. rerio. The results of 21-d dietary exposure experiment demonstrate that nC60 in D. magna decreased the body weight growths and condition factors of D. rerio, and reduced the food conversion ratio by 20% (from D. magna to D. rerio). Further, the experiments present that nC60 decrease three digestive enzymes activities of trypsinase, lipase, and amylase by 30, 29, and 55% in vivo, and by 60, 90, and 42% in vitro, respectively. Both in vivo and in vitro experiments indicated that nC60 was involved with the decrements of digestive enzymes activities. These decrements in digestive enzymes activities may be due to the deactivation caused by the adsorption of nC60 particles onto the surface or active center of digestive enzymes. Sum up, these results not only describe the nC60 deleterious effects on the food conversion from D. magna to D. rerio, but also provide some information regarding a probable food conversion inhibition mechanism of nC60. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Investigation of a Brazilian tannery effluent by means of zebra fish (Danio rerio) embryo acute toxicity (FET) test.

    Rocha, Otávio Pelegrino; De Oliveira, Danielle Palma

    2017-01-01

    Tannery effluents consist of a complex chemical composition not only limited to primary pollutants, which also require biological detection as these compounds may produce adverse effects. The fish embryo toxicity (FET) test with Danio rerio is an alternative method in hazard and risk assessment for determination of chemical-mediated effects. The aim of this investigation was to use the FET test to detect compounds and consequent effects in Brazilian tannery effluents. Samples were collected from the inlet and outlet of the effluent treatment plant at a tannery located in Restinga, São Paulo, Brazil. The toxicological effects were assessed using FET assay for a period of 144 hr using indices such as (1) coagulation of fertilized eggs, (2) lack of detachment of tail-bud from yolk sac, (3) absence of spontaneous movement, (4) yolk sack edema, (5) malformation of the tail, (6) scoliosis, and (7) deformation of swim bladder in the embryos. Data showed that effluent treatment plant exposure produced acute toxicity in D. rerio embryos as evidenced by coagulation of fertilized eggs in up to 5% of all diluted samples 24 hr post fertilization for inlet effluent samples compared to 100% coagulation for outlet samples. Results demonstrated that these effects may not be attributed to metals, but to other non-detected components, such as dyes, pigments, biocides, carriers, surfactants, or other organic compounds that might be present in these complex mixtures. The use of D. rerio embryos was found to be useful as an additional tool for ecotoxicity testing to assess the potential environmental acute toxicity influence of tannery effluents.

  12. Different phylogenomic approaches to resolve the evolutionary relationships among model fish species.

    Negrisolo, Enrico; Kuhl, Heiner; Forcato, Claudio; Vitulo, Nicola; Reinhardt, Richard; Patarnello, Tomaso; Bargelloni, Luca

    2010-12-01

    Comparative genomics holds the promise to magnify the information obtained from individual genome sequencing projects, revealing common features conserved across genomes and identifying lineage-specific characteristics. To implement such a comparative approach, a robust phylogenetic framework is required to accurately reconstruct evolution at the genome level. Among vertebrate taxa, teleosts represent the second best characterized group, with high-quality draft genome sequences for five model species (Danio rerio, Gasterosteus aculeatus, Oryzias latipes, Takifugu rubripes, and Tetraodon nigroviridis), and several others are in the finishing lane. However, the relationships among the acanthomorph teleost model fishes remain an unresolved taxonomic issue. Here, a genomic region spanning over 1.2 million base pairs was sequenced in the teleost fish Dicentrarchus labrax. Together with genomic data available for the above fish models, the new sequence was used to identify unique orthologous genomic regions shared across all target taxa. Different strategies were applied to produce robust multiple gene and genomic alignments spanning from 11,802 to 186,474 amino acid/nucleotide positions. Ten data sets were analyzed according to Bayesian inference, maximum likelihood, maximum parsimony, and neighbor joining methods. Extensive analyses were performed to explore the influence of several factors (e.g., alignment methodology, substitution model, data set partitions, and long-branch attraction) on the tree topology. Although a general consensus was observed for a closer relationship between G. aculeatus (Gasterosteidae) and Di. labrax (Moronidae) with the atherinomorph O. latipes (Beloniformes) sister taxon of this clade, with the tetraodontiform group Ta. rubripes and Te. nigroviridis (Tetraodontiformes) representing a more distantly related taxon among acanthomorph model fish species, conflicting results were obtained between data sets and methods, especially with respect

  13. Effectiveness of Rapid Cooling as a Method of Euthanasia for Young Zebrafish (Danio rerio).

    Wallace, Chelsea K; Bright, Lauren A; Marx, James O; Andersen, Robert P; Mullins, Mary C; Carty, Anthony J

    2018-01-01

    Despite increased use of zebrafish (Danio rerio) in biomedical research, consistent information regarding appropriate euthanasia methods, particularly for embryos, is sparse. Current literature indicates that rapid cooling is an effective method of euthanasia for adult zebrafish, yet consistent guidelines regarding zebrafish younger than 6 mo are unavailable. This study was performed to distinguish the age at which rapid cooling is an effective method of euthanasia for zebrafish and the exposure times necessary to reliably euthanize zebrafish using this method. Zebrafish at 3, 4, 7, 14, 16, 19, 21, 28, 60, and 90 d postfertilization (dpf) were placed into an ice water bath for 5, 10, 30, 45, or 60 min (n = 12 to 40 per group). In addition, zebrafish were placed in ice water for 12 h (age ≤14 dpf) or 30 s (age ≥14 dpf). After rapid cooling, fish were transferred to a recovery tank and the number of fish alive at 1, 4, and 12-24 h after removal from ice water was documented. Euthanasia was defined as a failure when evidence of recovery was observed at any point after removal from ice water. Results showed that younger fish required prolonged exposure to rapid cooling for effective euthanasia, with the required exposure time decreasing as fish age. Although younger fish required long exposure times, animals became immobilized immediately upon exposure to the cold water, and behavioral indicators of pain or distress rarely occurred. We conclude that zebrafish 14 dpf and younger require as long as 12 h, those 16 to 28 dpf of age require 5 min, and those older than 28 dpf require 30 s minimal exposure to rapid cooling for reliable euthanasia.

  14. Correlating gene expression with deformities caused by aryl hydrocarbon receptor agonists in zebrafish (Danio rerio)

    Bugiak, B.; Weber, L. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2009-07-01

    Exposure to aryl hydrocarbon receptor (AhR) agonists in fish causes lethal disturbances in fish development, but the effects of acute AhR agonist exposure on the cardiovascular system and deformities remain unclear. This study addressed this issue by performing a series of experiments on zebrafish (Danio rerio). The authors hypothesized that genes needed for cardiovascular regulation (PTGS) would exhibit a stronger link to deformities than detoxification enzymes (CYPs). Zebrafish eggs were exposed aqueously until 4 days post-fertilization (dpf) to the AhR agonists benzo(a)pyrene (BaP) or 2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) alone and in combination with the putative AhR antagonists resveratrol or alpha-naphthoflavone (ANF). Gene expression was measured using real-time, reverse transcriptase PCR in zebrafish at 5 and 10 dpf. Although the mortalities did not differ considerably among groups at 10 dpf, the deformities increased significantly after BaP-ANF at 5 dpf and after BaP at 10 dpf, but not after TCDD treatment. CYP and PTGS isozymes exhibited small, but statistically significant changes at 5 dpf. By 10 dpf, the expression returned to control values. In general, CYP1A and PTGS-1 expression at 5 dpf were positively correlated with deformities, while all other genes were negatively correlated with deformities. It was concluded that changes in CYP1A, CYP1C2, and PTGS-1 gene expression at 5 dpf are associated with developmental deformities, but additional work is needed to determine which has the most important mechanistic link.

  15. Impacts of 17α-ethynylestradiol exposure on metabolite profiles of zebrafish (Danio rerio) liver cells

    Teng, Quincy, E-mail: teng.quincy@epa.gov [National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605 (United States); Ekman, Drew R., E-mail: ekman.drew@epa.gov [National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605 (United States); Huang, Wenlin, E-mail: whuang2@ccny.cuny.edu [National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605 (United States); Collette, Timothy W., E-mail: collette.tim@epa.gov [National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605 (United States)

    2013-04-15

    Highlights: ► We apply NMR-based metabolomics to study responses of ZFL cells exposed to EE2. ► The metabolomics approach has capability to capture cellular response to exposure. ► The analysis provides detailed molecular information on chemical's mode of action. ► Cellular metabolomics may have application for screening chemical exposure/toxicity. -- Abstract: Endocrine disrupting chemicals (EDCs) that are frequently detected in bodies of water downstream from sewage treatment facilities can have adverse impacts on fish and other aquatic organisms. To properly assess risk(s) from EDCs, tools are needed that can establish linkages from chemical exposures to adverse outcomes. Traditional methods of testing chemical exposure and toxicity using experimental animals are excessively resource- and time-consuming. In line with EPA's goal of reducing animal use in testing, these traditional screening methods may not be sustainable in the long term, given the ever increasing number of chemicals that must be tested for safety. One of the most promising ways to reduce costs and increase throughput is to use cell cultures instead of experimental animals. In accordance with National Research Council's vision on 21st century toxicity testing, we have developed a cell culture-based metabolomics approach for this application. Using a zebrafish (Danio rerio) liver cell line (ZFL), we have applied NMR-based metabolomics to investigate responses of ZFL cells exposed to 17α-ethynylestradiol (EE2). This analysis showed that metabolite changes induced by EE2 exposure agree well with known impacts of estrogens on live fish. The results of this study demonstrate the potential of cell-based metabolomics to assess chemical exposure and toxicity for regulatory application.

  16. Histological and genotoxic evaluation of gold nanoparticles in ovarian cells of zebrafish (Danio rerio)

    Dayal, Navami, E-mail: navamidayal@gmail.com [MGM Institute of Health Sciences, Department of Medical Genetics (India); Thakur, Mansee, E-mail: mansibiotech79@gmail.com [MGM Institute of Health Sciences and College of Engineering and Technology, Department of Medical Biotechnology and Central Research Laboratory (India); Patil, Poonam, E-mail: poonamparth14@yahoo.in [MGM Institute of Health Sciences, Department of Medical Biotechnology (India); Singh, Dipty, E-mail: diptyasingh@gmail.com; Vanage, Geeta, E-mail: geetavanage@gmail.com [National Institute of Research in Reproductive Health (ICMR), National Centre for Preclinical Reproductive and Genetic Toxicology (NIRRH) (India); Joshi, D. S. [MGM Institute of Health Sciences, Department of Medical Genetics (India)

    2016-10-15

    Gold nanoparticles (AuNPs) have attracted a lot of attention due to their usage in consumer- and therapy-based biomedical applications. These particles are frequently the medium-sized particles within the range of 10–50 nm. A number of scientific reports have addressed the cytotoxic potential of these NPs. However, their genotoxic potential with respect to reproductive aspects remains unclear. For assessment of safety and risks associated with AuNPs to female reproductive system, adult female zebrafish (Danio rerio) were exposed in vivo to 20 μg/g/day of AuNPs of two different sizes. AuNPs of 15 nm (type I) and 47 nm (type II) in diameters were administered orally to female zebrafish for a period of 28 days (chronic). The ability of these AuNPs to gain access to female reproductive organs was confirmed by their accumulation pattern through inductive coupled plasma mass spectroscopy. Gonads were assessed for changes in ovarian morphology at histopathological level followed by the confirmation of bioaccumulation of AuNPs using transmission electron microscopy. Using comet assay, strand breaks in DNA of ovarian cells were investigated. Chronic exposure to type I and II AuNPs showed distinctive patterns of bioaccumulation in ovaries. Interestingly, accumulated NPs resulted in gross cellular alterations in different cell types of ovarian tissue. Comet assay analysis revealed extensive number of strand breaks in ovarian cells from the NP exposed fishes. In conclusion, AuNPs ranging between 10 and 50 nm are capable of gaining access to ovaries of zebrafish and potential enough to cause strand breaks in ovarian cells. The findings of the present study highlight the adverse effects of these NPs to female reproductive system. It opens up further avenues for research on effects of these NPs on F{sub 1} generation descending from the exposed fishes.

  17. Impacts of 17α-ethynylestradiol exposure on metabolite profiles of zebrafish (Danio rerio) liver cells

    Teng, Quincy; Ekman, Drew R.; Huang, Wenlin; Collette, Timothy W.

    2013-01-01

    Highlights: ► We apply NMR-based metabolomics to study responses of ZFL cells exposed to EE2. ► The metabolomics approach has capability to capture cellular response to exposure. ► The analysis provides detailed molecular information on chemical's mode of action. ► Cellular metabolomics may have application for screening chemical exposure/toxicity. -- Abstract: Endocrine disrupting chemicals (EDCs) that are frequently detected in bodies of water downstream from sewage treatment facilities can have adverse impacts on fish and other aquatic organisms. To properly assess risk(s) from EDCs, tools are needed that can establish linkages from chemical exposures to adverse outcomes. Traditional methods of testing chemical exposure and toxicity using experimental animals are excessively resource- and time-consuming. In line with EPA's goal of reducing animal use in testing, these traditional screening methods may not be sustainable in the long term, given the ever increasing number of chemicals that must be tested for safety. One of the most promising ways to reduce costs and increase throughput is to use cell cultures instead of experimental animals. In accordance with National Research Council's vision on 21st century toxicity testing, we have developed a cell culture-based metabolomics approach for this application. Using a zebrafish (Danio rerio) liver cell line (ZFL), we have applied NMR-based metabolomics to investigate responses of ZFL cells exposed to 17α-ethynylestradiol (EE2). This analysis showed that metabolite changes induced by EE2 exposure agree well with known impacts of estrogens on live fish. The results of this study demonstrate the potential of cell-based metabolomics to assess chemical exposure and toxicity for regulatory application

  18. Noninvasive technique for measurement of heartbeat regularity in zebrafish (Danio rerio embryos

    Cheng Shuk

    2009-02-01

    Full Text Available Abstract Background Zebrafish (Danio rerio, due to its optical accessibility and similarity to human, has emerged as model organism for cardiac research. Although various methods have been developed to assess cardiac functions in zebrafish embryos, there lacks a method to assess heartbeat regularity in blood vessels. Heartbeat regularity is an important parameter for cardiac function and is associated with cardiotoxicity in human being. Using stereomicroscope and digital video camera, we have developed a simple, noninvasive method to measure the heart rate and heartbeat regularity in peripheral blood vessels. Anesthetized embryos were mounted laterally in agarose on a slide and the caudal blood circulation of zebrafish embryo was video-recorded under stereomicroscope and the data was analyzed by custom-made software. The heart rate was determined by digital motion analysis and power spectral analysis through extraction of frequency characteristics of the cardiac rhythm. The heartbeat regularity, defined as the rhythmicity index, was determined by short-time Fourier Transform analysis. Results The heart rate measured by this noninvasive method in zebrafish embryos at 52 hour post-fertilization was similar to that determined by direct visual counting of ventricle beating (p > 0.05. In addition, the method was validated by a known cardiotoxic drug, terfenadine, which affects heartbeat regularity in humans and induces bradycardia and atrioventricular blockage in zebrafish. A significant decrease in heart rate was found by our method in treated embryos (p p Conclusion The data support and validate this rapid, simple, noninvasive method, which includes video image analysis and frequency analysis. This method is capable of measuring the heart rate and heartbeat regularity simultaneously via the analysis of caudal blood flow in zebrafish embryos. With the advantages of rapid sample preparation procedures, automatic image analysis and data analysis, this

  19. Combined effects of alpha particles and depleted uranium on Zebrafish (Danio rerio) embryos

    Ng, Candy Y.P.; Pereira, Sandrine; Cheng, Shuk Han; Adam-Guillermin, Christelle; Garnier-Laplace, Jacqueline; Yu, Kwan Ngok

    2016-01-01

    The combined effects of low-dose or high-dose alpha particles and depleted uranium (DU) in Zebrafish (Danio rerio) embryos were studied. Three schemes were examined—(i) [I L U L ]: 0.44 mGy alpha-particle dose + 10 µg/l DU exposure, (ii) [I H U H ]: 4.4 mGy alpha-particle dose + 100 µg/l DU exposure and (iii) [I H U L ]: 4.4 mGy alpha-particle dose + 10 µg/l DU exposure—in which Zebrafish embryos were irradiated with alpha particles at 5 h post fertilization (hpf) and/or exposed to uranium at 5–6 hpf. The results were also compared with our previous work, which studied the effects of [I L U H ]: 0.44 mGy alpha-particle dose + 100 µg/l DU exposure. When the Zebrafish embryos developed to 24 hpf, the apoptotic signals in the entire embryos, used as the biological endpoint for this study, were quantified. Our results showed that [I L U L ] and [I H U L ] led to antagonistic effects, whereas [I H U H ] led to an additive effect. The effect found for the previously studied case of [I L U H ] was difficult to define because it was synergistic with reference to the 100 µg/l DU exposure, but it was antagonistic with reference to the 0.44 mGy alpha-particle dose. All the findings regarding the four different schemes showed that the combined effects critically depended on the dose response to each individual stressor. We also qualitatively explained these findings in terms of promotion of early death of cells predisposed to spontaneous transformation by alpha particles, interacting with the delay in cell death resulting from various concentrations of DU exposure

  20. Histological and genotoxic evaluation of gold nanoparticles in ovarian cells of zebrafish ( Danio rerio)

    Dayal, Navami; Thakur, Mansee; Patil, Poonam; Singh, Dipty; Vanage, Geeta; Joshi, D. S.

    2016-10-01

    Gold nanoparticles (AuNPs) have attracted a lot of attention due to their usage in consumer- and therapy-based biomedical applications. These particles are frequently the medium-sized particles within the range of 10-50 nm. A number of scientific reports have addressed the cytotoxic potential of these NPs. However, their genotoxic potential with respect to reproductive aspects remains unclear. For assessment of safety and risks associated with AuNPs to female reproductive system, adult female zebrafish (Danio rerio) were exposed in vivo to 20 μg/g/day of AuNPs of two different sizes. AuNPs of 15 nm (type I) and 47 nm (type II) in diameters were administered orally to female zebrafish for a period of 28 days (chronic). The ability of these AuNPs to gain access to female reproductive organs was confirmed by their accumulation pattern through inductive coupled plasma mass spectroscopy. Gonads were assessed for changes in ovarian morphology at histopathological level followed by the confirmation of bioaccumulation of AuNPs using transmission electron microscopy. Using comet assay, strand breaks in DNA of ovarian cells were investigated. Chronic exposure to type I and II AuNPs showed distinctive patterns of bioaccumulation in ovaries. Interestingly, accumulated NPs resulted in gross cellular alterations in different cell types of ovarian tissue. Comet assay analysis revealed extensive number of strand breaks in ovarian cells from the NP exposed fishes. In conclusion, AuNPs ranging between 10 and 50 nm are capable of gaining access to ovaries of zebrafish and potential enough to cause strand breaks in ovarian cells. The findings of the present study highlight the adverse effects of these NPs to female reproductive system. It opens up further avenues for research on effects of these NPs on F1 generation descending from the exposed fishes.

  1. Effects of maternal exposure to estrogen and PCB on different life stages of Zebrafish (Danio rerio)

    Olsson, Per-Erik; Westerlund, L; Billsson, K; Berg, A H [Umeaa Univ. (Sweden). Dept. of Cellular and Developmental Biology; Teh, S J; Hinton, D E [California Univ., Davis, CA (United States). Dept. of Anatomy, Physiology and Cell Biology; Tysklind, M [Umeaa Univ., (Sweden). Dept. of Environmental Chemistry; Nilsson, Jan; Eriksson, Lars-Ove [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Aquaculture

    1999-02-01

    PCBs have been found to impair both reproduction and development in fish. We have investigated the effects of 3 PCB congeners, 2,3,3`,4,4`,5,6-HpCB (PCB-190); 2,3,4,4`-TeCB (PCB-60); and 2,2`,4,6,6`-PeCB (PCB-104), and the estrogenic hormone 17{beta}-estradiol on fecundity, early life-stage mortality, gross morphology and histology of zebrafish (Danio rerio). While none of the studied substances reduced fecundity, they increased embryo and larval mortality. The most severe effects on viability were observed following treatment with 17{beta}-estradiol or the weakly estrogenic PCB-104. Following 17{beta}-estradiol or PCB-104 exposure, mortality continued through the yolksac absorption phase. PCB-60, on the other hand, resulted in mortality between the 30% epiboly stage and 75% epiboly stage. At the same time as embryos started to die, embryo development and hatching were delayed. PCB-190 showed only moderate effects on early-life stage mortality. The fish were reared until sexual maturation where after they were subjected to gross morphological and histological analyses. Changes in morphology were observed following PCB-104 and PCB-190 treatment. Both substances gave rise to craniofacial malformations while PCB-104 also led to lordosis in females and scoliosis in fish of both sexes. From histological analysis it was found that PCB-104 and 17{beta}-estradiol resulted in karyorrhexis and karyolysis in the kidney. Possible signs of bile stasis were observed following 17{beta}-estradiol and PCB-190 treatment. Some effects were observed on the gonads, including areas in the ovary showing atresia and limited failure of testicular spermatogenesis in 17{beta}-estradiol, PCB-104, and PCB-60 treated fish. While all studied substances resulted in effects on offspring, the observation that estrogenic substances are highly embryotoxic, raises concern that endocrine disrupting substances may severely reduce fish populations in polluted areas

  2. Effects of Environmental Enrichment on the Fertility and Fecundity of Zebrafish (Danio rerio).

    Wafer, Lemnique N; Jensen, V Behrana; Whitney, Jesse C; Gomez, Thomas H; Flores, Rene; Goodwin, Bradford S

    2016-01-01

    Zebrafish (Danio rerio) are a popular vertebrate model in biomedical research, but information describing the effects of environmental enrichment on fertility and fecundity of zebrafish is sparse. In the current study, 18 breeding pairs were placed in divided 1.5-L breeding tanks containing 1 of 3 enrichment conditions: plastic grass (n = 6), plastic leaves (n = 6), or no enrichment (n = 6, control). The pairs were allowed to spawn for 3 h the next day, after which eggs were counted and breeding pairs were returned to holding tanks for use in subsequent sessions. Spawning sessions were repeated at 7-d intervals until the completion of 9 trials, with pairs rotating to a different condition at each interval. Total egg count (mean ± SEM) after 3 h was greater for zebrafish spawning in the grass environment (48.0 ± 7.7 eggs) than in the leaf or control environments (29.4 ± 5.3 and 20.4 ± 3.7 eggs, respectively). An interaction emerged between enrichment type and the age of the spawning pair on the number of fry at 6 d postfertilization (dpf). Initially, more fry were obtained from 110- and 160-dpf pairs with the grass enrichment, but from 173- and 180-dpf pairs there were more obtained with leaf enrichment than grass. A separate experiment showed that enrichment type did not have an effect on fry survivability. Overall, our data indicates that, under certain conditions, zebrafish fertility and fecundity are greater in a breeding tank containing environmental enrichment than in a bare tank.

  3. Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

    Ribeiro, Fabianne; Gallego-Urrea, Julián Alberto; Jurkschat, Kerstin; Crossley, Alison; Hassellöv, Martin; Taylor, Cameron; Soares, Amadeu M.V.M.; Loureiro, Susana

    2014-01-01

    Silver nanoparticles (AgNP) have gained attention over the years due to the antimicrobial function of silver, which has been exploited industrially to produce consumer goods that vary in type and application. Undoubtedly the increase of production and consumption of these silver-containing products will lead to the entry of silver compounds into the environment. In this study we have used Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio as model organisms to investigate the toxicity of AgNP and AgNO 3 by assessing different biological endpoints and exposure periods. Organisms were exposed following specific and standardized protocols for each species/endpoints, with modifications when necessary. AgNP were characterized in each test-media by Transmission Electron Microscopy (TEM) and experiments were performed by Dynamic Light Scattering (DLS) to investigate the aggregation and agglomeration behavior of AgNP under different media chemical composition and test-period. TEM images of AgNP in the different test-media showed dissimilar patterns of agglomeration, with some agglomerates inside an organic layer, some loosely associated particles and also the presence of some individual particles. The toxicity of both AgNO 3 and AgNP differ significantly based on the test species: we found no differences in toxicity for algae, a small difference for zebrafish and a major difference in toxicity for Daphnia magna. - Highlights: •Effects of silver nanoparticles and nitrate were compared in three aquatic species. •The presence of food on the immobilization assay for Daphnia magna significantly decreased AgNP toxicity. •AgNP and AgNO 3 differ in toxicity according to the test species and endpoint. •AgNP and AgNO 3 induced dissimilar abnormalities on zebrafish embryos' development. •AgNP behavior in the test media will rule its bioavailability and uptake and therefore toxicity

  4. Dopamine inhibits reproduction in female zebrafish (Danio rerio) via three pituitary D2 receptor subtypes.

    Fontaine, Romain; Affaticati, Pierre; Yamamoto, Kei; Jolly, Cécile; Bureau, Charlotte; Baloche, Sylvie; Gonnet, Françoise; Vernier, Philippe; Dufour, Sylvie; Pasqualini, Catherine

    2013-02-01

    In many teleosts, the stimulatory control of gonadotrope axis by GnRH is opposed by an inhibitory control by dopamine (DA). The functional importance of this inhibitory pathway differs widely from one teleostean species to another. The zebrafish (Danio rerio) is a teleost fish that has become increasingly popular as an experimental vertebrate model. However, the role of DA in the neuroendocrine control of its reproduction has never been studied. Here the authors evaluated in sexually regressed female zebrafish the effects of in vivo treatments with a DA D2 receptor (D2-R) antagonist domperidone, or a GnRH agonist, alone and in combination, on the pituitary level of FSHβ and LHβ transcripts, the gonadosomatic index, and the ovarian histology. Only the double treatment with GnRH agonist and domperidone could induce an increase in the expression of LHβ, in the gonadosomatic index, and a stimulation of ovarian vitellogenesis, indicating that removal of dopaminergic inhibition is required for the stimulatory action of GnRH and reactivation of ovarian function to occur. Using double immunofluorescent staining on pituitary, the authors showed in this species the innervation of LH cells by tyrosine-hydroxylase immunoreactive fibers. Finally, using in situ hybridization and immunofluorescence, the authors showed that the three subtypes of zebrafish DA D2-R (D2a, D2b, and D2c) were expressed in LH-producing cells, suggesting that they all may be involved in mediating this inhibition. These results show for the first time that, in zebrafish, DA has a direct and potent inhibitory action capable of opposing the stimulatory effect of GnRH in the neuroendocrine control of reproduction.

  5. Combinatorial effects of zinc deficiency and arsenic exposure on zebrafish (Danio rerio development.

    Laura M Beaver

    Full Text Available Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes.

  6. Histological and genotoxic evaluation of gold nanoparticles in ovarian cells of zebrafish (Danio rerio)

    Dayal, Navami; Thakur, Mansee; Patil, Poonam; Singh, Dipty; Vanage, Geeta; Joshi, D. S.

    2016-01-01

    Gold nanoparticles (AuNPs) have attracted a lot of attention due to their usage in consumer- and therapy-based biomedical applications. These particles are frequently the medium-sized particles within the range of 10–50 nm. A number of scientific reports have addressed the cytotoxic potential of these NPs. However, their genotoxic potential with respect to reproductive aspects remains unclear. For assessment of safety and risks associated with AuNPs to female reproductive system, adult female zebrafish (Danio rerio) were exposed in vivo to 20 μg/g/day of AuNPs of two different sizes. AuNPs of 15 nm (type I) and 47 nm (type II) in diameters were administered orally to female zebrafish for a period of 28 days (chronic). The ability of these AuNPs to gain access to female reproductive organs was confirmed by their accumulation pattern through inductive coupled plasma mass spectroscopy. Gonads were assessed for changes in ovarian morphology at histopathological level followed by the confirmation of bioaccumulation of AuNPs using transmission electron microscopy. Using comet assay, strand breaks in DNA of ovarian cells were investigated. Chronic exposure to type I and II AuNPs showed distinctive patterns of bioaccumulation in ovaries. Interestingly, accumulated NPs resulted in gross cellular alterations in different cell types of ovarian tissue. Comet assay analysis revealed extensive number of strand breaks in ovarian cells from the NP exposed fishes. In conclusion, AuNPs ranging between 10 and 50 nm are capable of gaining access to ovaries of zebrafish and potential enough to cause strand breaks in ovarian cells. The findings of the present study highlight the adverse effects of these NPs to female reproductive system. It opens up further avenues for research on effects of these NPs on F_1 generation descending from the exposed fishes.

  7. Paraquat affects mitochondrial bioenergetics, dopamine system expression, and locomotor activity in zebrafish (Danio rerio).

    Wang, Xiao H; Souders, Christopher L; Zhao, Yuan H; Martyniuk, Christopher J

    2018-01-01

    The dipyridyl herbicide paraquat induces oxidative stress in cells and is implicated in adult neurodegenerative diseases. However, less is known about paraquat toxicity in early stages of vertebrate development. To address this gap, zebrafish (Danio rerio) embryos were exposed to 1, 10 and 100 μM paraquat for 96 h. Paraquat did not induce significant mortality nor deformity in embryos and larvae, but it did accelerate time to hatch. To evaluate whether mitochondrial respiration was related to earlier hatch times, oxygen consumption rate was measured in whole embryos. Maximal respiration of embryos exposed to 100 μM paraquat for 24 h was reduced by more than 70%, suggesting that paraquat negatively impacts mitochondrial bioenergetics in early development. Based upon this evidence for mitochondrial dysfunction, transcriptional responses of oxidative stress- and apoptosis-related genes were measured. Fish exposed to 1 μM paraquat showed higher expression levels of superoxide dismutase 2, heat shock protein 70, Bcl-2-associated X protein, and B-cell CLL/lymphoma 2a compared to control fish. No differences among groups were detected in larvae exposed to 10 and 100 μM paraquat, suggesting a non-monotonic response. We also measured endpoints related to larval behavior and dopaminergic signaling as paraquat is associated with degeneration of dopamine neurons. Locomotor activity was stimulated with 100 μM paraquat and dopamine transporter and dopamine receptor 3 mRNA levels were increased in larvae exposed to 1 μM paraquat, interpreted to be a compensatory response at lower concentrations. This study improves mechanistic understanding into the toxic actions of paraquat on early developmental stages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

    Ribeiro, Fabianne, E-mail: ribeiro.f@ua.pt [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal); Gallego-Urrea, Julián Alberto [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Jurkschat, Kerstin; Crossley, Alison [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Hassellöv, Martin [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Taylor, Cameron [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Soares, Amadeu M.V.M.; Loureiro, Susana [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal)

    2014-01-01

    Silver nanoparticles (AgNP) have gained attention over the years due to the antimicrobial function of silver, which has been exploited industrially to produce consumer goods that vary in type and application. Undoubtedly the increase of production and consumption of these silver-containing products will lead to the entry of silver compounds into the environment. In this study we have used Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio as model organisms to investigate the toxicity of AgNP and AgNO{sub 3} by assessing different biological endpoints and exposure periods. Organisms were exposed following specific and standardized protocols for each species/endpoints, with modifications when necessary. AgNP were characterized in each test-media by Transmission Electron Microscopy (TEM) and experiments were performed by Dynamic Light Scattering (DLS) to investigate the aggregation and agglomeration behavior of AgNP under different media chemical composition and test-period. TEM images of AgNP in the different test-media showed dissimilar patterns of agglomeration, with some agglomerates inside an organic layer, some loosely associated particles and also the presence of some individual particles. The toxicity of both AgNO{sub 3} and AgNP differ significantly based on the test species: we found no differences in toxicity for algae, a small difference for zebrafish and a major difference in toxicity for Daphnia magna. - Highlights: •Effects of silver nanoparticles and nitrate were compared in three aquatic species. •The presence of food on the immobilization assay for Daphnia magna significantly decreased AgNP toxicity. •AgNP and AgNO{sub 3} differ in toxicity according to the test species and endpoint. •AgNP and AgNO{sub 3} induced dissimilar abnormalities on zebrafish embryos' development. •AgNP behavior in the test media will rule its bioavailability and uptake and therefore toxicity.

  9. Does uranium exposure induce oxidative stress and genotoxicity in the teleostean Danio rerio? first experimental results

    Barillet, S.; Devaux, A.; Simon, O.; Buet, A.; Pradines, C.

    2004-01-01

    Within the Envirhom research program, key advances have been obtained in uranium bioaccumulation and underlying mechanisms understanding in various biological models at the individual level. However, considering different scales of biological effects (from early to delayed ones, from low to high level of organization) is crucial to provide ecologically relevant indicators. Organisms counteract stress induced by pollutant exposure through a wide range of physiological responses being both dose and time dependent. Effects at higher hierarchical levels are always preceded by early changes in biological processes, from subtle biochemical disturbances to impaired physiological functions, increased susceptibility to other stresses, reduced life-span Within this global context, preliminary experiments were carried out on adult zebra fish (Danio rerio), to assess early changes after short-term uranium exposure. Among the subsequent primary subcellular damages oxidative stress and genotoxicity (characterizing both chemo-toxicity and radiotoxicity) are relevant endpoints, thus requiring the knowledge of dose-effects relationships as a first operational approach to provide useful tool in predicting possible effects of U exposure. Zebra fish has been selected due to its small size (facilitating its maintenance) and its extended use in eco-toxicological studies. Moreover, its short life-cycle will allow to carry out chronic exposure experiments (along the whole life-cycle). Four uranium concentrations (0, 20, 100 and 500μg.L -1 ) and five sampling times (0, 0.5, 1, 5 and 10 days) were selected. Catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured as oxidative stress bio-markers. DNA damage level was assessed in zebra fish erythrocytes using the comet assay. Uranium bioaccumulation was concurrently studied to understand observed bio-marker responses. Further experiments, dedicated to the assessment of the impact of chronic uranium

  10. Species specific anaesthetics for fish anaesthesia and euthanasia.

    Readman, Gareth D; Owen, Stewart F; Knowles, Toby G; Murrell, Joanna C

    2017-08-02

    There is a need to ensure that the care and welfare for fish maintained in the laboratory are to the highest standards. This extends to the use of anaesthetics for both scientific study, humane killing and euthanasia at end of life. An anaesthetic should not induce negative behaviours and fish should not seek to avoid the anaesthetic. Surprisingly little information is available to facilitate a humane choice of anaesthetic agent for fish despite over 100 years of use and the millions of fish currently held in thousands of laboratories worldwide. Using a chemotaxic choice chamber we found different species specific behavioural responses among four closely related fish species commonly held in the laboratory, exposed to three widely used anaesthetic agents. As previously found for zebrafish (Danio rerio), the use of MS-222 and benzocaine also appears to induce avoidance behaviours in medaka (Oryzias latipes); but etomidate could provide an alternative choice. Carp (Cyprinus carpio), although closely related to zebrafish showed avoidance behaviours to etomidate, but not benzocaine or MS-222; and rainbow trout (Oncorhynchus mykiss) showed no avoidance to the three agents tested. We were unable to ascertain avoidance responses in fathead minnows (Pimephales promelas) and suggest different test paradigms are required for that species.

  11. Fish from Head to Tail: The 9th European Zebrafish Meeting in Oslo.

    Griffiths, Gareth; Müller, Ferenc; Ledin, Johan; Patton, E Elizabeth; Gjøen, Tor; Lobert, Viola Hélène; Winther-Larsen, Hanne Cecilie; Mullins, Mary; Joly, Jean-Stephane; Weltzien, Finn-Arne; Press, Charles McLean; Aleström, Peter

    2016-04-01

    The 9th European Zebrafish Meeting took place recently in Oslo (June 28-July 2, 2015). A total of 650 participants came to hear the latest research news focused on the zebrafish, Danio rerio, and to its distant evolutionary relative medaka, Oryzias latipes. The packed program included keynote and plenary talks, short oral presentations and poster sessions, workshops, and strategic discussions. The meeting was a great success and revealed dramatically how important the zebrafish in particular has become as a model system for topics, such as developmental biology, functional genomics, biomedicine, toxicology, and drug development. A new emphasis was given to its potential as a model for aquaculture, a topic of great economic interest to the host country Norway and for the future global food supply in general. Zebrafish husbandry as well as its use in teaching were also covered in separate workshops. As has become a tradition in these meetings, there was a well-attended Wellcome Trust Sanger Institute and ZFIN workshop focused on Zebrafish Genome Resources on the first day. The full EZM 2015 program with abstracts can be read and downloaded from the EZM 2015 Web site zebrafish2015.org .

  12. The influence of magnetic field on the spatial orientation in zebrafish Danio rerio (Hamilton and roach Rutilus rutilus (L.

    Anastasia A. Batrakova

    2015-11-01

    Full Text Available Known, that some teleostei can perceive the geomagnetic field (GMF. However, the information about magnetosensitivity in Cyprinidae fish from artificial and natural habitats is obscure. We have registered preferred directions in Danio rerio (Hamilton from aquaria-cultivated line exposed to the natural GMF, 180 degrees reversal of horizontal GMF component, 180 degrees reversal of vertical GMF component, 180 degrees reversal of both vertical and horizontal GMF components and 90 degrees clockwise turn of horizontal GMF component. We also registered the preferred directions in Rutilus rutilus (L. from Rybinsk reservoir exposed to the natural GMF and 90 degrees clockwise turn of horizontal GMF component. It was found that zebrafish prefer two opposite directions towards east and west in the natural GMF. When the horizontal component of GMF was turned 90 degrees clockwise D. rerio prefer two opposite directions towards north and south. The possible reason of bimodality in zebrafish’s preferred directions distributions is discussed. The only direction towards east-north-east observed in roach under the natural GMF. This direction coincided with the way from the place of capture to the streamflow part of Rybinsk reservoir. And it was changed by south-south-east direction when turned the horizontal component of GMF 90 degrees clockwise. The possible reason of the choosing directions by fish with GMF is discussed.

  13. Effect of Enriched Feed by n-3 fatty acids and 2% of n-6 fatty acid on Danio rerio Reproduction

    N.B.P Utomo

    2007-07-01

    Full Text Available This experiment was conducted to determine the optimum n-3 fatty acid level in the diet containing 2 % of n-6 fatty acid on the reproductive performance of zebra fish (Danio rerio. There experimental diets containing 0.0; 1.0; 1.5 % n-3 fatty acid with 2.0 % n-6 fatty acid was fed to the fish, three times daily, at satiation, for two months. In order to evaluate the gonadal development of the broodstock, two gonads og fish was used for histologis preparation in every 7 days. At the end of the second month, reproductive performance was evaluated through parameters of gonad somato indeks, fecundity, fertilization rate, hatching rate, yolk egg absorbtion rate, survival rate of 3 days old larvae. Sample of fish also was taken for proximate composition as the end of this experiment. Results shows that at the fifth weeks of this experiment, gonad of fish fed on 1.0 % of n-3 fatty acid and 2.0 % n-6 fatty acid already produce eggs with the some size, while others. Still produce small size of eggs. It was found also that the whole body of fish fed an diet with 1.0% n-3 fatty acid contain the highest protein level compare to two other diets. Based on the evaluation of reproduction performance parameters, it was concluded that the optimum dietary level of n-3 fatty acid with 2.0 % n-6 fatty acid for Danio rerio was 0.81 - 0.90 %. Keywords: essential fatty, acids, reproduction, zebra fish, Danio rerio   ABSTRAK Penelitian ini bertujuan untuk menentukan kadar asam lemak n-3 optimum dalam pakan yang mempunyai kadar asam lemak n-6 tetap. Tiga macam pakan dengan kadar asam lemak n-3 berbeda yaitu 0.0; 1.0; dan 2.0 % diberikan pada ikan dengan bobot rata-rata 0.12 g. Pakan diberikan secara at satiation, 4 kali sehari selama 60 hari. Setiap 7 hari sekali diambil sampel ikan untuk pembentukan preparat histologi gonad dengan tujuan untuk mengevaluasi perkembangan gonad. Pada akhir penelitian, induk dipijahkan dan dievaluasi performan reproduksi berdasarkan

  14. Linking genomic responses of gonads with reproductive impairment in marine medaka (Oryzias melastigma) exposed chronically to the chemopreventive and antifouling agent, 3,3′-diindolylmethane (DIM)

    Chen, Lianguo [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR (China); Au, Doris W.T. [State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Hu, Chenyan [School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430072 (China); Zhang, Weipeng [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR (China); Zhou, Bingsheng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Cai, Lin [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR (China); Giesy, John P. [Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Department of Zoology, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI (United States); Qian, Pei-Yuan, E-mail: boqianpy@ust.hk [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR (China)

    2017-02-15

    Highlights: • Marine medaka were exposed chronically to low-doses of DIM. • Toxicogenomic responses of gonads were profiled at transcript and protein levels. • Molecular initiating events were linked to adverse apical outcomes. • VTG mobilization was blocked by lower abundance of cathepsin enzyme in ovary. • Eggshell proteins were more indicative of reproductive failure than VTG. - Abstract: 3,3′-Diindolylmethane (DIM) has been promoted as an effective chemopreventive and antifouling additive. However, the concurrent risks or side effects of DIM are not fully understood, especially on tissues responsive to estrogen. Therefore, this study employed marine medaka (Oryzias melastigma) as a test model to evaluate relative safety and explore mechanisms of toxic action of DIM on development and function of gonad after chronic (28 days) aqueous exposure to relatively low doses (0 μg/L or 8.5 μg/L). Integration of comprehensive toxicogenomic analysis at the transcriptome and proteome levels with apical endpoints, such as production of eggs and swimming performance of larvae, elucidated the molecular linkage in gonad from bottom up along the reproductive adverse outcome pathway. A series of sequential changes at the transcript and protein levels were linked to lesser fecundity and viability of larvae exposed to DIM. Anomalous production of vitellogenin (VTG) and eggshell proteins in testis confirmed the estrogenic potency of DIM. In the ovary, although storage of VTG was greater, lesser expressions of cathepsin enzymes blocked cleavage and incorporation of VTG into oocytes as yolk, which acted together with lower eggshell proteins to inhibit maturation of primary oocyte and thus contributed to impairment of fecundity. Overall, this study demonstrated that exposure to DIM impaired reproductive fitness. Diverse molecular initiating changes in gonads were linked to apical endpoints that could be used in assessment of risks posed by DIM on gametogenesis. In

  15. Linking genomic responses of gonads with reproductive impairment in marine medaka (Oryzias melastigma) exposed chronically to the chemopreventive and antifouling agent, 3,3′-diindolylmethane (DIM)

    Chen, Lianguo; Au, Doris W.T.; Hu, Chenyan; Zhang, Weipeng; Zhou, Bingsheng; Cai, Lin; Giesy, John P.; Qian, Pei-Yuan

    2017-01-01

    Highlights: • Marine medaka were exposed chronically to low-doses of DIM. • Toxicogenomic responses of gonads were profiled at transcript and protein levels. • Molecular initiating events were linked to adverse apical outcomes. • VTG mobilization was blocked by lower abundance of cathepsin enzyme in ovary. • Eggshell proteins were more indicative of reproductive failure than VTG. - Abstract: 3,3′-Diindolylmethane (DIM) has been promoted as an effective chemopreventive and antifouling additive. However, the concurrent risks or side effects of DIM are not fully understood, especially on tissues responsive to estrogen. Therefore, this study employed marine medaka (Oryzias melastigma) as a test model to evaluate relative safety and explore mechanisms of toxic action of DIM on development and function of gonad after chronic (28 days) aqueous exposure to relatively low doses (0 μg/L or 8.5 μg/L). Integration of comprehensive toxicogenomic analysis at the transcriptome and proteome levels with apical endpoints, such as production of eggs and swimming performance of larvae, elucidated the molecular linkage in gonad from bottom up along the reproductive adverse outcome pathway. A series of sequential changes at the transcript and protein levels were linked to lesser fecundity and viability of larvae exposed to DIM. Anomalous production of vitellogenin (VTG) and eggshell proteins in testis confirmed the estrogenic potency of DIM. In the ovary, although storage of VTG was greater, lesser expressions of cathepsin enzymes blocked cleavage and incorporation of VTG into oocytes as yolk, which acted together with lower eggshell proteins to inhibit maturation of primary oocyte and thus contributed to impairment of fecundity. Overall, this study demonstrated that exposure to DIM impaired reproductive fitness. Diverse molecular initiating changes in gonads were linked to apical endpoints that could be used in assessment of risks posed by DIM on gametogenesis. In

  16. Effects of the UV filter benzophenone-3 (oxybenzone) at low concentrations in zebrafish (Danio rerio)

    Blüthgen, Nancy [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); University of Basel, Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, Klingelbergstrasse 50, CH-4056 Basel (Switzerland); Zucchi, Sara [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH‐4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETHZ), Department of Environmental Sciences, CH‐8092 Zürich (Switzerland)

    2012-09-01

    Organic UV filters including benzophenone-3 (BP-3) are widely used to protect humans and materials from damage by UV irradiation. Despite the environmental occurrence of BP-3 in the aquatic environment, little is known about its effects and modes of action. In the present study we assess molecular and physiological effects of BP-3 in adult male zebrafish (Danio rerio) and in eleuthero-embryos by a targeted gene expression approach focusing on the sex hormone system. Fish and embryos are exposed for 14 days and 120 hours post fertilization, respectively, to 2.4–312 μg/L and 8.2–438 μg/L BP-3. Chemical analysis of water and fish demonstrates that BP-3 is partly transformed to benzophenone-1 (BP-1) and both compounds are accumulated in adult fish. Biotransformation to BP-1 is absent in eleuthero-embryos. BP-3 exposure leads to similar alterations of gene expression in both adult fish and eleuthero-embryos. In the brain of adult males esr1, ar and cyp19b are down-regulated at 84 μg/L BP-3. There is no induction of vitellogenin expression by BP-3, both at the transcriptional and protein level. An overall down-regulation of the hsd3b, hsd17b3, hsd11b2 and cyp11b2 transcripts is observed in the testes, suggesting an antiandrogenic activity. No histological changes were observed in the testes after BP-3 treatment. The study leads to the conclusion that low concentrations of BP-3 exhibit similar multiple hormonal activities at the transcription level in two different life stages of zebrafish. Forthcoming studies should show whether this translates to additional physiological effects. Highlights: ► Activity of UV filter benzophenone-3 (BP-3) is assessed in zebrafish. ► BP-3 is partly metabolized to benzophenone-1 by adult fish but not embryos. ► Alterations of gene expression are similar in adult males and embryos. ► Gene expression alterations point to multiple hormonal activity of BP-3.

  17. Tissue uptake, distribution and elimination of {sup 14}C-PFOA in zebrafish (Danio rerio)

    Ulhaq, Mazhar [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Sundström, Maria [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Larsson, Pia; Gabrielsson, Johan [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Bergman, Åke [Environmental Chemistry Unit, Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm (Sweden); Norrgren, Leif [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden); Örn, Stefan, E-mail: Stefan.Orn@slu.se [Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden)

    2015-06-15

    Highlights: • Bioconcentration of PFOA at steady-state was approximately 20–30 times. • High concentrations were observed in bile and intestines implying enterohepatic circulation. • PFOA accumulated in oocytes indicating maternal transfer. - Abstract: Perfluorooctanoic acid (PFOA) is a long-chain perfluorinated chemical that has been shown to be non-degradable and persistent in the environment. Laboratory studies on bioconcentration and compound-specific tissue distribution in fish can be valuable for prediction of the persistence and environmental effects of the chemicals. In the present study male and female zebrafish (Danio rerio) were continuously exposed to 10 μg/L of radiolabeled perfluorooctanoic acid ({sup 14}C-PFOA) for 40 days, after which the exposed fish were transferred to fresh clean water for another 80 days wash-out period. At defined periodic intervals during the uptake and wash-out, fish were sampled for liquid scintillation counting and whole body autoradiography to profile the bioconcentration and tissue distribution of PFOA. The steady-state concentration of {sup 14}C-PFOA in the zebrafish was reached within 20–30 days of exposure. The concentration-time course of {sup 14}C-PFOA displayed a bi-exponential decline during washout, with a terminal half-life of approximately 13–14 days. At steady-state the bioconcentration of {sup 14}C-PFOA into whole-body fish was approximately 20–30 times greater than that of the exposure concentration, with no differences between females and males. The bioconcentration factors for liver and intestine were approximately 100-fold of the exposure medium, while in brain, ovary and gall bladder the accumulation factors were in the range 15–20. Whole-body autoradiograms confirmed the highest labeling of PFOA in bile and intestines, which implies enterohepatic circulation of PFOA. The {sup 14}C-PFOA was also observed in maturing vitellogenic oocytes, suggesting chemical accumulation via yolk proteins

  18. Thyroid hormone regulates muscle function during cold acclimation in zebrafish (Danio rerio).

    Little, Alexander G; Seebacher, Frank

    2013-09-15

    Thyroid hormone (TH) is a universal regulator of growth, development and metabolism during cold exposure in mammals. In zebrafish (Danio rerio), TH regulates locomotor performance and metabolism during cold acclimation. The influence of TH on locomotor performance may be via its effect on metabolism or, as has been shown in mammals, by modulating muscle phenotypes. Our aim was to determine whether TH influences muscle phenotypes in zebrafish, and whether this could explain changes in swimming capacity in response to thermal acclimation. We used propylthiouracil and iopanoic acid to induce hypothyroidism in zebrafish over a 3-week acclimation period to either 18 or 28°C. To verify that physiological changes following hypothyroid treatment were in fact due to the action of TH, we supplemented hypothyroid fish with 3,5-diiodothryronine (T2) or 3,5,3'-triiodothyronine (T3). Cold-acclimated fish had significantly greater sustained swimming performance (Ucrit) but not burst speed. Greater Ucrit was accompanied by increased tail beat frequency, but there was no change in tail beat amplitude. Hypothyroidism significantly decreased Ucrit and burst performance, as well as tail beat frequency and SERCA activity in cold-acclimated fish. However, myofibrillar ATPase activity increased in cold-acclimated hypothyroid fish. Hypothyroid treatment also decreased mRNA concentrations of myosin heavy chain fast isoforms and SERCA 1 isoform in cold-acclimated fish. SERCA 1 mRNA increased in warm-acclimated hypothyroid fish, and SERCA 3 mRNA decreased in both cold- and warm-acclimated hypothyroid fish. Supplementation with either T2 or T3 restored Ucrit, burst speed, tail beat frequency, SERCA activity and myosin heavy chain and SERCA 1 and 3 mRNA levels of hypothyroid fish back to control levels. We show that in addition to regulating development and metabolism in vertebrates, TH also regulates muscle physiology in ways that affect locomotor performance in fish. We suggest that the

  19. Identification and characterization of a novel zebrafish (Danio rerio pentraxin–carbonic anhydrase

    Maarit S. Patrikainen

    2017-12-01

    Full Text Available Background Carbonic anhydrases (CAs are ubiquitous, essential enzymes which catalyze the conversion of carbon dioxide and water to bicarbonate and H+ ions. Vertebrate genomes generally contain gene loci for 15–21 different CA isoforms, three of which are enzymatically inactive. CA VI is the only secretory protein of the enzymatically active isoforms. We discovered that non-mammalian CA VI contains a C-terminal pentraxin (PTX domain, a novel combination for both CAs and PTXs. Methods We isolated and sequenced zebrafish (Danio rerio CA VI cDNA, complete with the sequence coding for the PTX domain, and produced the recombinant CA VI–PTX protein. Enzymatic activity and kinetic parameters were measured with a stopped-flow instrument. Mass spectrometry, analytical gel filtration and dynamic light scattering were used for biophysical characterization. Sequence analyses and Bayesian phylogenetics were used in generating hypotheses of protein structure and CA VI gene evolution. A CA VI–PTX antiserum was produced, and the expression of CA VI protein was studied by immunohistochemistry. A knock-down zebrafish model was constructed, and larvae were observed up to five days post-fertilization (dpf. The expression of ca6 mRNA was quantitated by qRT-PCR in different developmental times in morphant and wild-type larvae and in different adult fish tissues. Finally, the swimming behavior of the morphant fish was compared to that of wild-type fish. Results The recombinant enzyme has a very high carbonate dehydratase activity. Sequencing confirms a 530-residue protein identical to one of the predicted proteins in the Ensembl database (ensembl.org. The protein is pentameric in solution, as studied by gel filtration and light scattering, presumably joined by the PTX domains. Mass spectrometry confirms the predicted signal peptide cleavage and disulfides, and N-glycosylation in two of the four observed glycosylation motifs. Molecular modeling of the pentamer is

  20. Relative developmental toxicity of short-chain chlorinated paraffins in Zebrafish (Danio rerio) embryos.

    Liu, Lihua; Li, Yifan; Coelhan, Mehmet; Chan, Hing Man; Ma, Wanli; Liu, Liyan

    2016-12-01

    Short-chain chlorinated paraffins (SCCPs) are ubiquitous in the environment and might cause adverse environmental and human health effects. Little is known about the relative toxicity of different SCCP compounds especially during development. The objective of this study was to characterize and compare effects of seven SCCP groups at environmentally relevant levels, using a zebrafish (Danio rerio) model. Observations on malformation, survival rates at 96 h post fertilization (hpf), and hatching rates at 72 hpf indicated that the C 10- groups (C 10 H 18 Cl 4 , 1,2,5,6,9,10-C 10 H 16 Cl 6 and C 10 H 15 Cl 7 ) were more toxic than the C 12- groups (C 12 H 22 Cl 4 , C 12 H 19 Cl 7 and 1,1,1,3,10,12,12,12-C 12 H 18 Cl 8 ) and Cereclor 63L. The C 10- groups were also more potent than C 12- groups and Cereclor 63L in decreasing thyroid hormone levels. Among the three compounds within the C 10- group, the compounds with less chlorine content had stronger effects on sub-lethal malformations but less effects on triiodothyronine (T3) and tetraiodothyronine (T4). Only C 10 H 18 Cl 4 significantly decreased the mRNA expression of tyr, ttr, dio2 and dio3 at a dose-dependent manner suggesting that the specific mode of actions differ with different congeners. The mechanisms of disruption of thyroid status by different SCCPs could be different. C 10 H 18 Cl 4 might inhibit T3 production through the inhibition effect on dio2. These results indicate that SCCP exposure could alter gene expression in the hypothalamic-pituitary-thyroid (HPT) axis and thyroid hormone levels. The mechanisms of disruption of thyroid status by different SCCPs could be different. Our results on the relative developmental toxicities of SCCPs will be useful to reach a better understanding of SCCP toxicity supporting environmental risk evaluation and regulation and used as a guidance for environmental monitoring of SCCPs in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Chronic effects of clofibric acid in zebrafish (Danio rerio): a multigenerational study.

    Coimbra, Ana M; Peixoto, Maria João; Coelho, Inês; Lacerda, Ricardo; Carvalho, António Paulo; Gesto, Manuel; Lyssimachou, Angeliki; Lima, Daniela; Soares, Joana; André, Ana; Capitão, Ana; Castro, Luís Filipe C; Santos, Miguel M

    2015-03-01

    Clofibric acid (CA) is an active metabolite of the blood lipid lowering agent clofibrate, a pharmaceutical designed to work as agonist of peroxisome proliferator-activated receptor alpha (PPARa). It is the most commonly reported fibrate in aquatic environments with low degradation rate and potential environmental persistence. Previous fish exposures showed that CA may impact spermatogenesis, growth and the expression of fat binding protein genes. However, there are limited data on the effects of chronic multigenerational CA exposures. Here, we assessed chronic multigenerational effects of CA exposure using zebrafish (Danio rerio) as a teleost model. Zebrafish were exposed through the diet to CA (1 and 10mg/g) during their whole lifetime. Growth, reproduction-related parameters and embryonic development were assessed in the exposed fish (F1 generation) and their offspring (F2 generation), together with muscle triglyceride content and gonad histology. In order to study the potential underlying mechanisms, the transcription levels of genes coding for enzymes involved in lipid metabolism pathways were determined. The results show that chronic life-cycle exposure to CA induced a significant reduction in growth of F1 generation and lowered triglyceride muscle content (10mg/g group). Also, an impact in male gonad development was observed together with a decrease in the fecundity (10mg/g group) and higher frequency of embryo abnormalities in the offspring of fish exposed to the lowest CA dose. The profile of the target genes was sex- and tissue-dependent. In F1 an up-regulation of male hepatic pparaa, pparb and acox transcript levels was observed, suggesting an activation of the fatty acid metabolism (provided that transcript level change indicates also a protein level change). Interestingly, the F2 generation, raised with control diet, displayed a response pattern different from that observed in F1, showing an increase in weight in the descendants of CA exposed fish, in

  2. Enantioselective developmental toxicity and immunotoxicity of pyraclofos toward zebrafish (Danio rerio)

    Zhuang, Shulin, E-mail: shulin@zju.edu.cn [Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058 (China); Zhang, Zhisheng [Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang, Wenjing; Bao, Lingling [Institute of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058 (China); Xu, Chao, E-mail: chaoxu@zjut.edu.cn [Research Center of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Zhang, Hu [Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 210021 (China)

    2015-02-15

    Highlights: • Pyraclofos has significant enantioselective aquatic toxicities to zebrafish. • Pyraclofos induces time- and concentration-dependent developmental toxicity and immunotoxicity. • The mRNA level of IL-1β gene was significantly up-regulated by pyraclofos. • Pyraclofos binds potently to IL-1β, potentially affecting IL-1β-dependent proinflammatory signal transduction. • Our in vitro and in silico studies help to understand the molecular basis for aquatic toxicity of pyraclofos. - Abstract: Pyraclofos, a relatively new organophosphorus pesticide, has shown potential ecotoxicities, however, its aquatic toxicity, especially enantioselective aquatic toxicity, remains largely unknown. Using zebrafish (Danio rerio) as a preeminent vertebrate aquatic model, the enantioselective differences in the developmental toxicity and immunotoxicity of pyraclofos were evaluated. Following 96-h exposure, pyraclofos enantiomers exhibited acute toxicity and showed lethal concentration 50 of 2.23 and 3.99 mg/L for (R)-Pyraclofos and (S)-Pyraclofos, respectively. Exposure to pyraclofos caused time- and concentration-dependent malformations such as pericardial edema, yolk sac edema, crooked bodies and hatching during the embryonic development, with markedly higher percentages of malformation at higher concentrations. The concentration-dependent immunotoxicity to zebrafish embryo exposed to low level pyraclofos was induced with significant up-regulation of mRNA levels of immune-related interleukin-1β (IL-1β) gene. (R)-Pyraclofos was consistently more toxic than (S)-Pyraclofos for the acute toxicity, developmental toxicity and immunotoxicity to zebrafish. Molecular dynamics simulations revealed that at the atomic level, (R)-Pyraclofos binds more potently to IL-1β protein than (S)-Pyraclofos. This enantioselective binding is mainly contributed by the distinct binding mode of pyraclofos enantiomers and their electrostatic interactions with IL-1β, which potentially

  3. Quercetin, a natural product supplement, impairs mitochondrial bioenergetics and locomotor behavior in larval zebrafish (Danio rerio).

    Zhang, Ji-Liang; Laurence Souders, Christopher; Denslow, Nancy D; Martyniuk, Christopher J

    2017-07-15

    Quercetin is a natural product that is sold as a supplement in health food stores. While there are reported benefits for this flavonoid as a dietary supplement due to antioxidant properties, the full scope of its biological interactions has not been fully addressed. To learn more about the mechanisms of action related to quercetin, we exposed zebrafish (Danio rerio) embryos to 1 and 10μg/L quercetin for 96h starting at 3h post fertilization. Quercetin up to 10μg/L did not induce significant mortality in developing fish, but did increase prevalence of an upward-curved dorsal plane in hatched larvae. To determine whether this developmental defect was potentially related to mitochondrial bioenergetics during development, we measured oxygen consumption rate in whole embryos following a 24-hour exposure to quercetin. Basal mitochondrial and ATP-linked respiration were decreased at 1 and 10μg/L quercetin, and maximal respiration was decreased at 10μg/L quercetin, suggesting that quercetin impairs mitochondrial bioenergetics. This is proposed to be related to the deformities observed during development. Due to the fact that ATP production was affected by quercetin, larval behaviors related to locomotion were investigated, as well as transcriptional responses of six myogenesis transcripts. Quercetin at 10μg/L significantly reduced the swimming velocity of zebrafish larvae. The expression levels of both myostatin A (mstna) and myogenic differentiation (myoD) were also altered by quercetin. Mstna, an inhibitory factor for myogenesis, was significantly increased at 1μg/L quercetin exposure, while myoD, a stimulatory factor for myogenesis, was significantly increased at 10μg/L quercetin exposure. There were no changes in transcripts related to apoptosis (bcl2, bax, casp3, casp7), but we did observe a decrease in mRNA levels for catalase (cat) in fish exposed to each dose, supporting an oxidative stress response. Our data support the hypothesis that quercetin may affect

  4. Enantioselective developmental toxicity and immunotoxicity of pyraclofos toward zebrafish (Danio rerio)

    Zhuang, Shulin; Zhang, Zhisheng; Zhang, Wenjing; Bao, Lingling; Xu, Chao; Zhang, Hu

    2015-01-01

    Highlights: • Pyraclofos has significant enantioselective aquatic toxicities to zebrafish. • Pyraclofos induces time- and concentration-dependent developmental toxicity and immunotoxicity. • The mRNA level of IL-1β gene was significantly up-regulated by pyraclofos. • Pyraclofos binds potently to IL-1β, potentially affecting IL-1β-dependent proinflammatory signal transduction. • Our in vitro and in silico studies help to understand the molecular basis for aquatic toxicity of pyraclofos. - Abstract: Pyraclofos, a relatively new organophosphorus pesticide, has shown potential ecotoxicities, however, its aquatic toxicity, especially enantioselective aquatic toxicity, remains largely unknown. Using zebrafish (Danio rerio) as a preeminent vertebrate aquatic model, the enantioselective differences in the developmental toxicity and immunotoxicity of pyraclofos were evaluated. Following 96-h exposure, pyraclofos enantiomers exhibited acute toxicity and showed lethal concentration 50 of 2.23 and 3.99 mg/L for (R)-Pyraclofos and (S)-Pyraclofos, respectively. Exposure to pyraclofos caused time- and concentration-dependent malformations such as pericardial edema, yolk sac edema, crooked bodies and hatching during the embryonic development, with markedly higher percentages of malformation at higher concentrations. The concentration-dependent immunotoxicity to zebrafish embryo exposed to low level pyraclofos was induced with significant up-regulation of mRNA levels of immune-related interleukin-1β (IL-1β) gene. (R)-Pyraclofos was consistently more toxic than (S)-Pyraclofos for the acute toxicity, developmental toxicity and immunotoxicity to zebrafish. Molecular dynamics simulations revealed that at the atomic level, (R)-Pyraclofos binds more potently to IL-1β protein than (S)-Pyraclofos. This enantioselective binding is mainly contributed by the distinct binding mode of pyraclofos enantiomers and their electrostatic interactions with IL-1β, which potentially

  5. Cardiac and metabolic physiology of early larval zebrafish (Danio rerio reflects parental swimming stamina

    Warren W Burggren

    2012-02-01

    Full Text Available Swimming stamina in adult fish is heritable, it is unknown if inherited traits that support enhanced swimming stamina in offspring appear only in juveniles and/or adults, or if these traits actually appear earlier in the morphologically quite different larvae. To answer this question, mature adult zebrafish (Danio rerio were subjected to a swimming performance test that allowed separation into low swimming stamina or high swimming stamina groups. Adults were then bred within their own performance groups. Larval offspring from each of the two groups, designated high (LHSD and low stamina-derived larvae (LLSD, were then reared at 27°C in aerated water (21% O2. Routine (fH,r and active (fH,a heart rate, and routine (M.O2,r and active (M.O2,a mass-specific oxygen consumption were recorded from 5 days post fertilization (dpf through 21 dpf, and gross cost of transport and factorial aerobic metabolic scope were derived from M.O2 measurements. Heart rate generally ranged between 150 and 225 b•min-1 in both LHSD and LLSD populations. However, significant (P<0.05 differences existed between the LLSD and LHSD populations at 5 and 14 dpf in fH,r and at days 10 and 15 dpf in fH,a. M.O2,r was 0.04 to 0.32 μmol•mg-1•hr-1, while M.O2,a was 0.2 to 1.2 μmol•mg-1•hr-1. Significant (P<0.05 differences between the LLSD and LHSD populations in M.O2,r occurred at 7, 10 and 21 dpf and in M.O2,a at 7 dpf. Gross cost of transport was ~6-10 µmol O2 . µg-1 . m-1 at 5 dpf, peaking at 14-19 µmol O2 . µg-1 . m-1 at 7-10 dpf, before falling again to 5-6 µmol O2 . µg-1 . m-1 at 21 dpf, with gross cost of transport significantly higher in the LLSD population at 7 dpf. Collectively, these data indicate that inherited physiological differences contributing to enhanced stamina in adult parents appear in their larval offspring well before attainment of juvenile or adult features.

  6. Reversibility of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the estrogen 17α-ethinylestradiol

    Baumann, Lisa; Knörr, Susanne; Keiter, Susanne

    2014-01-01

    The aim of the present study was to investigate the persistence of the feminizing effects of discontinued 17α-ethinylestradiol (EE2) exposure on zebrafish (Danio rerio). An exposure scenario covering the sensitive phase of sexual differentiation, as well as final gonad maturation was chosen...... to examine the estrogenic effects on sexual development of zebrafish. Two exposure scenarioswere compared: continuous exposure to environmentally relevant concentrations (0.1–10 ng/L EE2) up to 100 days post-hatch (dph) and developmental exposure up to 60 dph, followed by 40 days of depuration in clean water....... The persistence of effects was investigated at different biological organization levels from mRNA to population-relevant endpoints to cover a broad range of important parameters. EE2 had a strong feminizing and inhibiting effect on the sexual development of zebrafish. Brain aromatase (cyp19b)mRNA expression...

  7. Persistence of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the androgen 17β-trenbolone

    Baumann, Lisa; Knörr, Susanne; Keiter, Susanne

    2014-01-01

    The aim of the present study was to investigate the effects of the androgenic endocrine disruptor 17β-trenbolone on the sexual development of zebrafish (Danio rerio) with special emphasis on the question whether adverse outcomes of developmental exposure are reversible or persistent. An exposure...... scenario including a recovery phase was chosen to assess the potential reversibility of androgenic effects. Zebrafish were exposed to environmentally relevant concentrations of 17β-trenbolone (1 - 30 ng/L) from fertilization until completion of gonad sexual differentiation (60 days post-hatch, dph...... with respect to exposure duration nor to concentration. Gonad morphological masculinization as well as the decrease of vitellogenin persisted after depuration over 40 d in clean water. This lack of recovery suggests that androgenic effects on sexual development of zebrafish are irreversible....

  8. Ultrastructural effects on gill, muscle, and gonadal tissues induced in zebrafish (Danio rerio) by a waterborne uranium exposure

    Barillet, Sabrina; Larno, Valerie; Floriani, Magali; Devaux, Alain; Adam-Guillermin, Christelle

    2010-01-01

    Experiments on adult zebrafish (Danio rerio) were conducted to assess histopathological effects induced on gill, muscle, and gonadal tissues after waterborne uranium exposure. Although histopathology is often employed as a tool for the detection and assessment of xenobiotic-mediated effects in aquatic organisms, few studies have been dedicated to the investigation of histopathological consequences of uranium exposure in fish. Results showed that gill tissue architecture was markedly disrupted. Major symptoms were alterations of the secondary lamellae epithelium (from extensive oedema to desquamation), hyperplasia of chloride cells, and breakdown of the pillar cell system. Muscle histology was also affected. Degeneration and disorganization of myofibrillar sarcomeric pattern as well as abnormal localization of mitochondria within muscle and altered endomysial sheaths were observed. Morphological alterations of spermatozoa within the gonadal tissue were also noticed. This study demonstrated that uranium exposure induced a variety of histological impairments in fish, supporting environmental concerns when uranium contaminates aquatic systems.

  9. First molecular identification of the transgene red fluorescent protein (RFP in transgenic ornamental zebrafish (Danio rerio introduced in Peru

    Carlos Scotto

    2013-09-01

    Full Text Available In this paper the transgenic fluorescent red, orange and pink zebra fish (Danio rerio, found in local aquariums in Peru, were identified using the PCR technique to amplify the transgene RFP sea anemone belonging to Discosoma spp. The gene expression of the red fluorescent protein (RFP transgene was found to determine different gradients-of-bioluminescence (shades in color in each GMO fish analyzed. We performed sequence analysis of the two variants of the RFP along with six variants of the existing fluorescent protein GFP from the Genbank, this could help identify quickly if they are new genes or variants thereof as these novel fluorescent proteins may be introduced in aquatic GMO in the future. Thus, developing and improving biosecurity measures through its timely detection at the molecular genetic level.

  10. Uptake and localization of fluorescent labelled gold nanoparticles in living zebrafish (Danio rerio) using Light Sheet Microscopy

    Skjolding, Lars Michael; Asmonaite, G.; Jolk, R.

    2015-01-01

    Despite nanoparticles being used in many different products and applications, the effects and fate in the environment are still not well understood. Uptake of nanoparticles into cells has been shown in vitro and in vivo. However, it is challenging to find suitable methods to identify uptake...... and determine localization on a whole organism level. Furthermore, methods used to identify nanoparticle uptake have been associated with artefacts induced by sample preparation including staining methods for electron microscopy.  This study used Fluorescent Light Sheet Microscopy (FLSM) to determine uptake...... to the particles through the diet or the water phase in a series of separate experiments. In the dietary exposure experiments Artemia salina were exposed to 1 mg Au/L for 24h before being fed to D. rerio. For exposure through the water phase 1 mg Au/L was added directly to aquaria holding the fish and non...

  11. Ultrastructural effects on gill, muscle, and gonadal tissues induced in zebrafish (Danio rerio) by a waterborne uranium exposure

    Barillet, Sabrina, E-mail: sabrina.barillet@free.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Larno, Valerie, E-mail: valerie.larno@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Floriani, Magali, E-mail: magali.floriani@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Devaux, Alain, E-mail: alain.devaux@entpe.fr [INRA, EFPA Department, 54280, Champenoux and Environmental Science Laboratory, ENTPE, 69518 Vaulx en Velin cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological Protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France)

    2010-11-01

    Experiments on adult zebrafish (Danio rerio) were conducted to assess histopathological effects induced on gill, muscle, and gonadal tissues after waterborne uranium exposure. Although histopathology is often employed as a tool for the detection and assessment of xenobiotic-mediated effects in aquatic organisms, few studies have been dedicated to the investigation of histopathological consequences of uranium exposure in fish. Results showed that gill tissue architecture was markedly disrupted. Major symptoms were alterations of the secondary lamellae epithelium (from extensive oedema to desquamation), hyperplasia of chloride cells, and breakdown of the pillar cell system. Muscle histology was also affected. Degeneration and disorganization of myofibrillar sarcomeric pattern as well as abnormal localization of mitochondria within muscle and altered endomysial sheaths were observed. Morphological alterations of spermatozoa within the gonadal tissue were also noticed. This study demonstrated that uranium exposure induced a variety of histological impairments in fish, supporting environmental concerns when uranium contaminates aquatic systems.

  12. Effects of Di-butyl Phthalate (DBP) on Developing Medaka Embryos

    Tang, Sherry

    2012-01-01

    Plasticizers are chemical additives that enhance plastic flexibility. They are ubiquitous environmental contaminants and are commonly found in river and lake waters (Fromme et al 2002). The present study aimed to investigate the effects of a water-soluble plasticizer, dibutyl phthalate (DBP) on developing Medaka ("Oryzias latipes") embryos. Three…

  13. Genotoxic and histopathological biomarkers for assessing the effects of magnetic exfoliated vermiculite and exfoliated vermiculite in Danio rerio

    Cáceres-Vélez, Paolin Rocio; Fascineli, Maria Luiza; Koppe Grisolia, Cesar; Oliveira Lima, Emília Celma de; Sousa, Marcelo Henrique; Morais, Paulo César de; Bentes de Azevedo, Ricardo

    2016-01-01

    Magnetic exfoliated vermiculite is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. It was developed primarily to mitigate pollution, but the possible adverse impacts of its application have not yet been evaluated. In this context, the acute toxicity of magnetic exfoliated vermiculite and exfoliated vermiculite was herein assessed by genotoxic and histopathological biomarkers in zebrafish (Danio rerio). DNA fragmentation was statistically significant for all groups exposed to the magnetic exfoliated vermiculite and for fish exposed to the highest concentration (200 mg/L) of exfoliated vermiculite, whereas the micronucleus frequency, nuclear abnormalities and histopathological alterations were not statistically significant for the fish exposed to these materials. In the intestinal lumen, epithelial cells and goblet cells, we found the presence of magnetic exfoliated vermiculite and exfoliated vermiculite, but no alterations or presence of the materials-test in the gills or liver were observed. Our findings suggest that the use of magnetic exfoliated vermiculite and exfoliated vermiculite during standard ecotoxicological assays caused DNA damage in D. rerio, whose alterations may be likely to be repaired, indicating that the magnetic nanoparticles have the ability to promote genotoxic damage, such as DNA fragmentation, but not mutagenic effects. - Highlights: • MEV is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. • The use of MEV and EV during standard ecotoxicological assays caused DNA fragmentation in zebrafish. • The magnetic nanoparticles showed ability to promote genotoxic damage, but did not induce micronucleus in peripheral erythrocytes at 96 h of exposure. • The tested concentrations of MEV and EV do not cause significant histopathological alterations in the gills, liver and intestine of zebrafish.

  14. The Mode of Action of Isocyanide in Three Aquatic Organisms, Balanus amphitrite, Bugula neritina and Danio rerio

    Zhang, Yi-Fan

    2012-09-18

    Isocyanide is a potential antifouling compound in marine environments. In this study, we investigated its mode of action in three aquatic organisms. Two of them, the bryozoan Bugula neritina and the barnacle Balanus amphitrite, are major marine fouling invertebrates, and the other organism is the non-target species zebrafish Danio rerio. In the swimming larvae of B. neritina, isocyanide did not affect the total attachment rate (≤50 µg ml^(−1)), but it did change the attachment site by increasing the percentage of attachment on the bottom of the container rather than on the wall or air-water inter-surface. Isocyanide binds several proteins in B. neritina as identified via SDS-PAGE-LC-MS/MS: 1) a 30 kD protein band containing two proteins similar to voltage dependent anion channels (VDAC), which control the direct coupling of the mitochondrial matrix to the energy maintenance of the cytosol and the release of apoptogenic factors from mitochondria of mammalian cells; and 2) an unknown 39 kD protein. In B. amphitrite cyprids, the isocyanide binding protein were 1) a protein similar to NADH-ubiquinone oxidoreductase, which is the “entry enzyme” of oxidative phosphorylation in mitochondria; and 2) cytochrome P450. In Danio rerio embryos, isocyanide caused “wavy” notochords, hydrocephalus, pericardial edema, poor blood circulation, and defects in pigmentation and hematopoiesis, which phenocopied copper deficiency. This is the first report on isocyanide binding proteins in fouling organisms, as well as the first description of its phenotype and potential toxicology in zebrafish.

  15. Genotoxic and histopathological biomarkers for assessing the effects of magnetic exfoliated vermiculite and exfoliated vermiculite in Danio rerio

    Cáceres-Vélez, Paolin Rocio; Fascineli, Maria Luiza; Koppe Grisolia, Cesar [Department of Genetics and Morphology, Institute of Biological Sciences, Brasília University, Brasília (Brazil); Oliveira Lima, Emília Celma de [Chemistry Institute, Federal University of Goiás, Goiânia (Brazil); Sousa, Marcelo Henrique [Green Nanotechnology Group, Faculty of Ceilândia, Brasília University, Brasília (Brazil); Morais, Paulo César de [Physics Institute, Brasília University, Brasília (Brazil); Huazhong University of Science and Technology, School of Automation, Wuhan 430074 (China); Bentes de Azevedo, Ricardo, E-mail: razevedo@unb.br [Department of Genetics and Morphology, Institute of Biological Sciences, Brasília University, Brasília (Brazil)

    2016-05-01

    Magnetic exfoliated vermiculite is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. It was developed primarily to mitigate pollution, but the possible adverse impacts of its application have not yet been evaluated. In this context, the acute toxicity of magnetic exfoliated vermiculite and exfoliated vermiculite was herein assessed by genotoxic and histopathological biomarkers in zebrafish (Danio rerio). DNA fragmentation was statistically significant for all groups exposed to the magnetic exfoliated vermiculite and for fish exposed to the highest concentration (200 mg/L) of exfoliated vermiculite, whereas the micronucleus frequency, nuclear abnormalities and histopathological alterations were not statistically significant for the fish exposed to these materials. In the intestinal lumen, epithelial cells and goblet cells, we found the presence of magnetic exfoliated vermiculite and exfoliated vermiculite, but no alterations or presence of the materials-test in the gills or liver were observed. Our findings suggest that the use of magnetic exfoliated vermiculite and exfoliated vermiculite during standard ecotoxicological assays caused DNA damage in D. rerio, whose alterations may be likely to be repaired, indicating that the magnetic nanoparticles have the ability to promote genotoxic damage, such as DNA fragmentation, but not mutagenic effects. - Highlights: • MEV is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. • The use of MEV and EV during standard ecotoxicological assays caused DNA fragmentation in zebrafish. • The magnetic nanoparticles showed ability to promote genotoxic damage, but did not induce micronucleus in peripheral erythrocytes at 96 h of exposure. • The tested concentrations of MEV and EV do not cause significant histopathological alterations in the gills, liver and intestine of zebrafish.

  16. Impacts of different exposure scenarios on transcript abundances in Danio rerio embryos when investigating the toxicological burden of riverine sediments.

    Kerstin Bluhm

    Full Text Available PURPOSE: Recently, a proof-of-concept study revealed the suitability of transcriptome analyses to obtain and assess changes in the abundance of transcripts in zebrafish (Danio rerio embryos after exposure to organic sediment extracts. The present study investigated changes in the transcript abundance in zebrafish embryos exposed to whole sediment samples and corresponding organic extracts in order to identify the impact of different exposure pathways on sediment toxicity. MATERIALS AND METHODS: Danio rerio embryos were exposed to sublethal concentrations of three sediment samples from the Danube River, Germany. The sediment samples were investigated both as freeze-dried samples and as organic extracts. Silica dust and a process control of the extraction procedure were used as references. After exposure, mRNA was isolated and changes in profiles of gene expression levels were examined by an oligonucleotide microarray. The microarray results were compared with bioassays, chemical analysis of the sediments and profiles of gene expression levels induced by several single substances. RESULTS AND DISCUSSION: The microarray approach elucidated significant changes in the abundance of transcripts in exposed zebrafish embryos compared to the references. Generally, results could be related to Ah-receptor-mediated effects as confirmed by bioassays and chemical analysis of dioxin-like contaminants, as well as to exposure to stress-inducing compounds. Furthermore, the results indicated that mixtures of chemicals, as present in sediment and extract samples, result in complex changes of gene expression level profiles difficult to compare with profiles induced by single chemical substances. Specifically, patterns of transcript abundances were less influenced by the chemical composition at the sampling site compared t the method of exposure (sediment/extract. This effect might be related to different bioavailability of chemicals. CONCLUSIONS: The apparent

  17. Uptake and release kinetics of 134Cs by goldfish (Carassius auratus) and 137Cs by zebra fish (Brachydanio rerio) in controlled aquatic environment

    Srivastava, A.; Reddy, S.J.; Kelber, O.; Urich, K.; Denschlag, H.O.

    1994-01-01

    The uptake and release kinetics of 134 Cs by Goldfish (Carassius auratus) and 137 Cs by Zebra Fish (Brachydanio rerio) from aquatic media of different ionic compositions and temperature was studied in controlled laboratory conditions. The accumulation of radiocesium in the case of Brachydanio rerio is observed to be strongly dependent on the potassium ion concentration of the aquatic medium, but in the case of Carassius auratus this dependence is quite weak. The biological half-lives of the cesium isotopes incorporated into the fish investigated in the present work vary from 19 to 80 days and are influenced by the temperature and the ionic composition of the aquatic medium. (author) 19 refs.; 1 fig.; 3 tabs

  18. Influences of humic acid on the bioavailability of phenanthrene and alkyl phenanthrenes to early life stages of marine medaka (Oryzias melastigma)

    Liu, Yangzhi; Yang, Chenghu; Cheng, Pakkin; He, Xiaojing; Zhu, Yaxian; Zhang, Yong

    2016-01-01

    The influences of humic acid (HA) on the environmental behavior and bioavailability of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs were investigated and compared using the early life stages of marine medaka (Oryzias melastigma, O. melastigma). It was demonstrated that the binding affinity of parent phenanthrene (PHE) with HA was smaller than that of 3-methyl phenanthrene (3-MP) and 9-ethyl phenanthrene (9-EP). Furthermore, the bioaccumulation of the three PAHs and the levels of lipid peroxidation (LPO) were calculated to study the changes in bioavailability of PAHs in presence of HA. The results indicated that the addition of HA significantly decreased the bioaccumulation and toxicity of PAHs by decreasing free PAHs concentrations. The bioavailable fractions of HA-bound PAHs in bioaccumulation (α) and toxicity (β) were evaluated, indicating that the HA-bound 3-MP and 9-EP show higher bioavailability in bioaccumulation and lower bioavailability in toxicity relative to those of PHE. The β/α values were less than 1 for all PAH treatment groups containing HA, suggesting that the fraction of HA-bound PAHs contributing to bioaccumulation was higher than that of HA-bound PAHs inducing toxic effect. In addition, we proposed that the free PAHs generated by desorption from HA in the cell were toxic by showing that the β/α ratio values are correlated with the log K_O_W values (p = 0.007 and R"2 = 0.8355). Thus, oil spill risk assessments should consider both alkyl PAHs and the factors that influence the bioavailability and toxicity of PAHs in the natural aquatic environments. - Highlights: • Effects of HA on bioavailability of parent and alkyl PAHs were firstly compared. • Changes in the bioavailability due to HA depended on the alkylation of PAHs. • The bioavailable fractions of the HA-bound parent and alkyl PAHs were calculated. • The toxicity of HA-bound PAHs was related to the physicochemical properties of PAHs. - This study is the

  19. Hypoxia induces telomerase reverse transcriptase (TERT gene expression in non-tumor fish tissues in vivo: the marine medaka (Oryzias melastigma model

    Mok Helen OL

    2006-09-01

    Full Text Available Abstract Background Current understanding on the relationships between hypoxia, hypoxia-inducible factor-1 (HIF-1 and telomerase reverse transcriptase (TERT gene expression are largely based on in vitro studies in human cancer cells. Although several reports demonstrated HIF-1- mediated upregulation of the human TERT gene under hypoxia, conflicting findings have also been reported. Thus far, it remains uncertain whether these findings can be directly extrapolated to non-tumor tissues in other whole animal systems in vivo. While fish often encounter environmental hypoxia, the in vivo regulation of TERT by hypoxia in non-neoplastic tissues of fish remains virtually unknown. Results The adult marine medaka (Oryzias melastigma was employed as a model fish in this study. We have cloned and characterized a 3261-bp full-length TERT cDNA, omTERT, which encodes a protein of 1086 amino acids. It contains all of the functional motifs that are conserved in other vertebrate TERTs. Motif E is the most highly conserved showing 90.9–100% overall identity among the fish TERTs and 63.6% overall identity among vertebrates. Analysis of the 5'-flanking sequence of the omTERT gene identified two HRE (hypoxia-responsive element; nt. – 283 and – 892 cores. Overexpression of the HIF-1α induced omTERT promoter activity as demonstrated using transient transfection assays. The omTERT gene is ubiquitously expressed in fish under normoxia, albeit at varying levels, where highest expression was observed in gonads and the lowest in liver. In vivo expression of omTERT was significantly upregulated in testis and liver in response to hypoxia (at 96 h and 48 h, respectively, where concomitant induction of the omHIF-1α and erythropoietin (omEpo genes was also observed. In situ hybridization analysis showed that hypoxic induction of omTERT mRNA was clearly evident in hepatocytes in the caudal region of liver and in spermatogonia-containing cysts in testis. Conclusion This

  20. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma)

    Chen, Lianguo [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region (Hong Kong); Ye, Rui [State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Xu, Ying; Gao, Zhaoming [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region (Hong Kong); Au, Doris W.T. [State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Qian, Pei-Yuan, E-mail: boqianpy@ust.hk [Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region (Hong Kong)

    2014-04-01

    Highlights: • Adverse effects of antifouling compound butenolide were studied using marine medaka. • The active ingredient in SeaNine 211, DCOIT, was employed as positive control. • Butenolide induced transient, reversible biological effects on marine medaka. • Lower toxicity of butenolide on marine biota highlights its promising application. • The increased sensitivity of male medaka addresses the gender difference. - Abstract: This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E{sub 2}) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E{sub 2}/T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be

  1. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma)

    Chen, Lianguo

    2014-04-01

    This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E2) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E2/T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be gradually recovered during depuration. Moreover, the endocrine disruptive effect induced by butenolide did not affect normal development of offspring. In contrast, DCOIT-exposed fish exhibited a decrease of egg production and impaired reproductive success. Overall, the above findings demonstrated that chronic exposure to butenolide induced transient, reversible biological effect on marine medaka, while DCOIT could impair reproductive success of fish, as

  2. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma)

    Chen, Lianguo; Ye, Rui; Xu, Ying; Gao, Zhaoming; Au, Doris W.T.; Qian, Pei-Yuan

    2014-01-01

    Highlights: • Adverse effects of antifouling compound butenolide were studied using marine medaka. • The active ingredient in SeaNine 211, DCOIT, was employed as positive control. • Butenolide induced transient, reversible biological effects on marine medaka. • Lower toxicity of butenolide on marine biota highlights its promising application. • The increased sensitivity of male medaka addresses the gender difference. - Abstract: This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E 2 ) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E 2 /T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be gradually

  3. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma).

    Chen, Lianguo; Ye, Rui; Xu, Ying; Gao, Zhaoming; Au, Doris W T; Qian, Pei-Yuan

    2014-04-01

    This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E2) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E2/T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be gradually recovered during depuration. Moreover, the endocrine disruptive effect induced by butenolide did not affect normal development of offspring. In contrast, DCOIT-exposed fish exhibited a decrease of egg production and impaired reproductive success. Overall, the above findings demonstrated that chronic exposure to butenolide induced transient, reversible biological effect on marine medaka, while DCOIT could impair reproductive success of fish, as

  4. Behavioral, endocrine, and neuronal alterations in zebrafish (Danio rerio) following sub-chronic coadministration of fluoxetine and ketamine.

    Pittman, Julian; Hylton, Andrew

    2015-12-01

    Most existing pharmacological treatments have focused on the "monoamine hypothesis" for targeted drug design for major depressive disorder (MDD). Many of these medications have a delayed onset-of-action and limited efficacy. Antidepressants with principal targets outside the monoamine system may offer the potential for more rapid activity with improved therapeutic benefit. Growing evidence suggests that the glutamatergic system is uniquely central to the neurobiology and treatment of MDD. Ketamine (Ketalar®) is a non-competitive glutamatergic antagonist classically used to induce sedation. However, preliminary clinical evidence has been promising with regard to its rapidly acting antidepressant profile. Zebrafish (Danio rerio) have emerged as a promising new animal model to screen the effects of numerous psychotropic compounds. This study aimed to determine if a sub-chronic low (sub-anesthetic) dose of ketamine could be used to augment the antidepressant effects of the widely used antidepressant fluoxetine (Prozac®) in adult zebrafish, employing an ethanol withdrawal model. Sub-chronic exposure to dosages of 100μg/L fluoxetine and 20mg/L of ketamine reduced anxiety/depression-like behaviors, leads to upregulation of serotonin synthesis and elevated whole-body cortisol levels. These results demonstrate the utility of zebrafish as a model for neuropharmacological research, and the possible efficacy of fluoxetine and ketamine coadministration. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. DarT: The embryo test with the Zebrafish Danio rerio--a general model in ecotoxicology and toxicology.

    Nagel, Roland

    2002-01-01

    The acute fish test is an animal test whose ecotoxicological relevance is worthy of discussion. The primary aim of protection in ecotoxicology is the population and not the individual. Furthermore the concentration of pollutants in the environment is normally not in the lethal range. Therefore the acute fish test covers solely the situation after chemical spills. Nevertheless, acute fish toxicity data still belong to the base set used for the assessment of chemicals. The embryo test with the zebrafish Danio rerio (DarT) is recommended as a substitute for the acute fish test. For validation an international laboratory comparison test was carried out. A summary of the results is presented in this paper. Based on the promising results of testing chemicals and waste water the test design was validated by the DIN-working group "7.6 Fischei-Test". A normed test guideline for testing waste water with fish is available. The test duration is short (48 h) and within the test different toxicological endpoints can be examined. Endpoints from the embryo test are suitable for QSAR-studies. Besides the use in ecotoxicology the introduction as a toxicological model was investigated. Disturbance of pigmentation and effects on the frequency of heart-beat were examined. A further important application is testing of teratogenic chemicals. Based on the results DarT could be a screening test within preclinical studies.

  6. Mitochondrial energetic metabolism perturbations in skeletal muscles and brain of zebrafish (Danio rerio) exposed to low concentrations of waterborne uranium

    Lerebours, Adelaide; Adam-Guillermin, Christelle [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Bat 186, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Brethes, Daniel [CNRS, UMR 5095, Institut de Biochimie et Genetique Cellulaires, Universite Victor Segalen-Bordeaux 2 (France); Frelon, Sandrine; Floriani, Magali; Camilleri, Virginie; Garnier-Laplace, Jacqueline [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Bat 186, BP 3, 13115 Saint-Paul-Lez-Durance Cedex (France); Bourdineaud, Jean-Paul, E-mail: jp.bourdineaud@epoc.u-bordeaux1.fr [CNRS, UMR 5095, Institut de Biochimie et Genetique Cellulaires, Universite Victor Segalen-Bordeaux 2 (France)

    2010-10-01

    Anthropogenic release of uranium (U), originating from the nuclear fuel cycle or military activities, may considerably increase U concentrations in terrestrial and aquatic ecosystems above the naturally occurring background levels found throughout the environment. With a projected increase in the world-wide use of nuclear power, it is important to improve our understanding of the possible effects of this metal on the aquatic fauna at concentrations commensurate with the provisional drinking water guideline value of the World Health Organization (15 {mu}g U/L). The present study has examined the mitochondrial function in brain and skeletal muscles of the zebrafish, Danio rerio, exposed to 30 and 100 {mu}g/L of waterborne U for 10 and 28 days. At the lower concentration, the basal mitochondrial respiration rate was increased in brain at day 10 and in muscles at day 28. This is due to an increase of the inner mitochondrial membrane permeability, resulting in a decrease of the respiratory control ratio. In addition, levels of cytochrome c oxidase subunit IV (COX-IV) increased in brain at day 10, and those of COX-I increased in muscles at day 28. Histological analyses performed by transmission electron microscopy revealed an alteration of myofibrils and a dilatation of endomysium in muscle cells. These effects were largest at the lowest concentration, following 28 days of exposure.

  7. Molecular Cloning and Functional Characterization of Mannose Receptor in Zebra Fish (Danio rerio during Infection with Aeromonas sobria

    Feifei Zheng

    2015-05-01

    Full Text Available Mannose receptor (MR is a member of pattern-recognition receptors (PRRs, which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in fish. In this report, a MR gene (designated as zfMR was cloned from zebra fish (Danio rerio, which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II domain, eight C-type lectin-like domains (CTLDs, a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected zebra fish. The established zebra fish-A. sobria infection model will be valuable for elucidating the role of MR in fish immune responses to infection.

  8. Differential Lectin Binding Patterns Identify Distinct Heart Regions in Giant Danio (Devario aequipinnatus) and Zebrafish (Danio rerio) Hearts

    Manalo, Trina; May, Adam; Quinn, Joshua; Lafontant, Dominique S.; Shifatu, Olubusola; He, Wei; Gonzalez-Rosa, Juan M.; Burns, Geoffrey C.; Burns, Caroline E.; Burns, Alan R.; Lafontant, Pascal J.

    2016-01-01

    Lectins are carbohydrate-binding proteins commonly used as biochemical and histochemical tools to study glycoconjugate (glycoproteins, glycolipids) expression patterns in cells, tissues, including mammalian hearts. However, lectins have received little attention in zebrafish (Danio rerio) and giant danio (Devario aequipinnatus) heart studies. Here, we sought to determine the binding patterns of six commonly used lectins—wheat germ agglutinin (WGA), Ulex europaeus agglutinin, Bandeiraea simplicifolia lectin (BS lectin), concanavalin A (Con A), Ricinus communis agglutinin I (RCA I), and Lycopersicon esculentum agglutinin (tomato lectin)—in these hearts. Con A showed broad staining in the myocardium. WGA stained cardiac myocyte borders, with binding markedly stronger in the compact heart and bulbus. BS lectin, which stained giant danio coronaries, was used to measure vascular reconstruction during regeneration. However, BS lectin reacted poorly in zebrafish. RCA I stained the compact heart of both fish. Tomato lectin stained the giant danio, and while low reactivity was seen in the zebrafish ventricle, staining was observed in their transitional cardiac myocytes. In addition, we observed unique staining patterns in the developing zebrafish heart. Lectins’ ability to reveal differential glycoconjugate expression in giant danio and zebrafish hearts suggests they can serve as simple but important tools in studies of developing, adult, and regenerating fish hearts. PMID:27680670

  9. Chronic exposure of μg/L range Bisphenol A to adult zebrafish (Danio rerio) leading to adipogenesis

    Ngo, Mai Thi; Doan, Thao Thi-Phuong; Nguyen, Cong Thanh; Vo, Diem Thi-Ngoc; Do, Chi Hong-Lan; Le, Nga Phi

    2017-09-01

    Bisphenol A (BPA) is known as an endocrine disruptor compound and commonly found in food-packaging plastics and in aquatic environment. It is scientifically concerned that BPA may causes significant health risks to human and aquatic animals. In fact, most of scientific studies have been conducted with BPA-acute toxicity in early stages of animal development, while far lesser researches have been focused on BPA-chronic toxicity in adults. This study was to investigate the chronic effects of environmental 1, 10 and 100 µg/L BPA to four-week-old zebrafishes (Danio rerio) after 60 days of exposure in terms of changing of body morphology, hepatocyte morphology and the transcriptional expression of biomarker gene for lipid metabolism. As a result, significant effects were found in: 1/ the increase of body weight, but not body length; 2/ the increase in the number of vacuolated hepatocytes corresponding to relatively higher glycogen and lipid content; 3/ shifting hepatocyte morphology to basophilic cytoplasm and cytoplasmic and/or nuclear enlargement, but not inflammation signs (macrophages, granuloma, fibrosis/cirrhosis); 4/ the decrease of mRNA level of PPARγ and C/EBPα genes in liver. Our study here indicates that the exposure to μg/L range concentration of BPA leads to adipogensis in adult zebrafishes.

  10. Assessing the toxicity of Pb- and Sn-based perovskite solar cells in model organism Danio rerio

    Babayigit, Aslihan; Duy Thanh, Dinh; Ethirajan, Anitha; Manca, Jean; Muller, Marc; Boyen, Hans-Gerd; Conings, Bert

    2016-01-01

    Intensive development of organometal halide perovskite solar cells has lead to a dramatic surge in power conversion efficiency up to 20%. Unfortunately, the most efficient perovskite solar cells all contain lead (Pb), which is an unsettling flaw that leads to severe environmental concerns and is therefore a stumbling block envisioning their large-scale application. Aiming for the retention of favorable electro-optical properties, tin (Sn) has been considered the most likely substitute. Preliminary studies have however shown that Sn-based perovskites are highly unstable and, moreover, Sn is also enlisted as a harmful chemical, with similar concerns regarding environment and health. To bring more clarity into the appropriateness of both metals in perovskite solar cells, we provide a case study with systematic comparison regarding the environmental impact of Pb- and Sn-based perovskites, using zebrafish (Danio Rerio) as model organism. Uncovering an unexpected route of intoxication in the form of acidification, it is shown that Sn based perovskite may not be the ideal Pb surrogate.

  11. Imaging of human glioblastoma cells and their interactions with mesenchymal stem cells in the zebrafish (Danio rerio) embryonic brain

    Vittori, Milos; Breznik, Barbara; Gredar, Tajda; Hrovat, Katja; Bizjak Mali, Lilijana; Lah, Tamara T

    2016-01-01

    An attractive approach in the study of human cancers is the use of transparent zebrafish (Danio rerio) embryos, which enable the visualization of cancer progression in a living animal. We implanted mixtures of fluorescently labeled glioblastoma (GBM) cells and bonemarrow-derived mesenchymal stem cells (MSCs) into zebrafish embryos to study the cellular pathways of their invasion and the interactions between these cells in vivo. By developing and applying a carbocyanine-dye-compatible clearing protocol for observation of cells in deep tissues, we showed that U87 and U373 GBM cells rapidly aggregated into tumor masses in the ventricles and midbrain hemispheres of the zebrafish embryo brain, and invaded the central nervous system, often using the ventricular system and the central canal of the spinal cord. However, the GBM cells did not leave the central nervous system. With co-injection of differentially labeled cultured GBM cells and MSCs, the implanted cells formed mixed tumor masses in the brain. We observed tight associations between GBM cells and MSCs, and possible cell-fusion events. GBM cells and MSCs used similar invasion routes in the central nervous system. This simple model can be used to study the molecular pathways of cellular processes in GBM cell invasion, and their interactions with various types of stromal cells in double or triple cell co-cultures, to design anti-GBM cell therapies that use MSCs as vectors

  12. Evaluation of Octhylphenol Effect on Development and Survival on Zebra Fish (Danio Rerio During Different Ontogenic Period

    Gabi Dumitrescu

    2010-05-01

    Full Text Available This paper is part of a complex study of our research collective that studies the toxic effect of the ethinylestradiolum, and some of the polyethoxylated alkylphenols on the growth and reproduction of the Zebra fish (Danio rerio and of the common Carp (Cyprinus carpio. Our study aim was to evaluate the effect of octylphenol on growth and survival of zebra fish, from 21-115 days, and within 21-75 days of life. For this purpose, for each period under study, fishes were divided into three groups of 30 individuals, named: Lot 1 - Control, respectively lots 2 and 3, at which the administrated octylphenol concentrations were of 60 μg L-1, respectively 100 μg L-1. Fishes of the six groups were raised in 30-liters aquariums (30 fish / aquarium. The growth was measured by weighing and biometric measurements (total length, standard length, the length of the head, maximal height, minimal height and the mass of the body, while the surviving rate was established at the end of every period and at the end of the experiment, when we were able to calculate the total number of dead fish. Biometric study of the analysis performed in 75 days, 115 days respectively shows that octylphenol has negative influence on body development, and survival both, the highest percentage of mortality (46,66% was registered at 100 μgL-1 concentration, between 21 -75 days.

  13. Acute Exposure to Microcystin-Producing Cyanobacterium Microcystis aeruginosa Alters Adult Zebrafish (Danio rerio Swimming Performance Parameters

    Luiza Wilges Kist

    2011-01-01

    Full Text Available Microcystins (MCs are toxins produced by cyanobacteria (blue-green algae, primarily Microcystis aeruginosa, forming water blooms worldwide. When an organism is exposed to environmental perturbations, alterations in normal behavioral patterns occur. Behavioral repertoire represents the consequence of a diversity of physiological and biochemical alterations. In this study, we assessed behavioral patterns and whole-body cortisol levels of adult zebrafish (Danio rerio exposed to cell culture of the microcystin-producing cyanobacterium M. aeruginosa (MC-LR, strain RST9501. MC-LR exposure (100 μg/L decreased by 63% the distance traveled and increased threefold the immobility time when compared to the control group. Interestingly, no significant alterations in the number of line crossings were found at the same MC-LR concentration and time of exposure. When animals were exposed to 50 and 100 μg/L, MC-LR promoted a significant increase (around 93% in the time spent in the bottom portion of the tank, suggesting an anxiogenic effect. The results also showed that none of the MC-LR concentrations tested promoted significant alterations in absolute turn angle, path efficiency, social behavior, or whole-body cortisol level. These findings indicate that behavior is susceptible to MC-LR exposure and provide evidence for a better understanding of the ecological consequences of toxic algal blooms.

  14. Assessing the toxicity of Pb- and Sn-based perovskite solar cells in model organism Danio rerio

    Babayigit, Aslihan; Duy Thanh, Dinh; Ethirajan, Anitha; Manca, Jean; Muller, Marc; Boyen, Hans-Gerd; Conings, Bert

    2016-01-01

    Intensive development of organometal halide perovskite solar cells has lead to a dramatic surge in power conversion efficiency up to 20%. Unfortunately, the most efficient perovskite solar cells all contain lead (Pb), which is an unsettling flaw that leads to severe environmental concerns and is therefore a stumbling block envisioning their large-scale application. Aiming for the retention of favorable electro-optical properties, tin (Sn) has been considered the most likely substitute. Preliminary studies have however shown that Sn-based perovskites are highly unstable and, moreover, Sn is also enlisted as a harmful chemical, with similar concerns regarding environment and health. To bring more clarity into the appropriateness of both metals in perovskite solar cells, we provide a case study with systematic comparison regarding the environmental impact of Pb- and Sn-based perovskites, using zebrafish (Danio Rerio) as model organism. Uncovering an unexpected route of intoxication in the form of acidification, it is shown that Sn based perovskite may not be the ideal Pb surrogate. PMID:26759068

  15. An assessment of the importance ofexposure routes to the uptake and internal localisation of fluorescent nanoparticles in zebrafish (Danio rerio), using light sheet microscopy

    Skjolding, Lars Michael; Ašmonaitė, G; Jølck, Rasmus Irming

    2017-01-01

    A major challenge in nanoecotoxicology is finding suitable methods to determine the uptake and localisation of nanoparticles on a whole-organism level. Some uptake methods have been associated with artefacts induced by sample preparation, including staining for electron microscopy. This study used...... light sheet microscopy (LSM) to define the uptake and localisation of fluorescently labelled nanoparticles in living organisms with minimal sample preparation. Zebrafish (Danio rerio) were exposed to fluorescent gold nanoparticles (Au NPs) and fluorescent polystyrene NPs via aqueous or dietary exposure...

  16. Effekte des Schwermetalls Platin auf die frühe Individualentwicklung des Zebrabärblings (Danio rerio) und der Paradies-Schnecke (Marisa cornuarietis)

    Osterauer, Raphaela

    2010-01-01

    Seit der Einführung des Kfz-Katalysators werden die Platingruppenelemente Platin, Palladium und Rhodium vermehrt in die Umwelt eingetragen und gelangen u.a. über Straßenabflussgewässer in aquatische Ökosysteme. Die vorliegende Arbeit untersuchte die Effekte verschiedener Konzentrationen des löslichen Platinchlorids (0, 0.1, 10, 50, 100 und 200 µg/L PtCl2) auf verschiedene Endpunkte während der frühen Individualentwicklung der beiden Süßwasserorganismen Zebrabärbling (Danio rerio) und Para...

  17. The effects of waterborne uranium on the hatching success, development, and survival of early life stages of zebrafish (Danio rerio)

    Bourrachot, Stephanie; Simon, Olivier; Gilbin, Rodolphe

    2008-01-01

    In this study, we investigated the effects of the radioactive metal uranium (U) on the embryonic development, hatching success, growth rate, and survival of juvenile zebrafish (Danio rerio). We studied the effects of depleted uranium (20-500 μg L -1 of DU), inducing mainly chemical toxicity due to its low specific activity, and the combined effects of chemical and radiological toxicity by using a higher specific activity uranium isotope (20 and 100 μg L -1 of 233 U). Results showed that early life stages are significantly affected by uranium exposure through both chemical and combined (chemical and radiological) toxicity. Experiments showed significant effects of U on hatching success starting at the concentration of 250 μg L -1 of DU, causing a 42% delay in median hatching times relative to control. Furthermore, a reduction of growth (decrease in body length and weight) was observed followed by a high mortality of pro-larvae stage (up to 100% at DU concentrations of 250 μg L -1 upon a 15 day exposure). Bioaccumulation measurements highlighted that U was mainly localised in the chorion but penetrated in the embryo inside eggs at a higher concentration. The effects differed depending on the isotopic composition of the uranium: sublethal defects in the tail detachment process were more pronounced for 233 U than DU exposure, while the presence of 233 U specifically affected embryo development and led to higher mortality rates of the prolarvae. The results from this study showed that the early life stages of zebrafish seems to be more sensitive to uranium contamination than more mature stages, and underline the importance of including pro-larval stages into toxicity tests in order to improve the relevancy for environmental risk assessments

  18. Toxicity of effluents from gasoline stations oil-water separators to early life stages of zebrafish Danio rerio.

    Alves, Romulo Nepomuceno; Mariz, Célio Freire; Paulo, Driele Ventura de; Carvalho, Paulo S M

    2017-07-01

    Used petroleum hydrocarbons and gasoline stations runoff are significant sources of polycyclic aromatic hydrocarbons (PAHs) to aquatic ecosystems. Samples of the final effluent of oil-water-separators were collected at gasoline stations in the metropolitan region of Recife, Brazil, before release to sewage or rainwater systems. Effluent soluble fractions (ESF) were prepared and bioassays were performed according to the Fish Embryo Toxicity Test. The test involved exposing zebrafish Danio rerio embryos to dilutions of the ESFs for 96 h, with daily examination of lethality and sublethal morphological effects integrated through the General Morphology Score (GMS), based on the achievement of developmental hallmarks. Frequencies of abnormalities were recorded after exposures. ESF LC50-96h (lethal concentration to 50% of exposed embryos) in the most toxic effluent achieved 8.9% (v/v), equivalent to 11 μg phenanthrene equivalents L -1 . GMS scores indicated significantly delayed embryo-larval development at ESF dilutions of 10% and 20% from effluents of all gas stations. Major abnormalities detected after the 96 h exposure included the presence of a yolk sac not fully absorbed coupled with the lack of an inflated swim bladder, lack of both pectoral fins, and the failure to develop a protruding mouth. Effective equivalent PAH concentrations that induce a 50% frequency of larvae without an inflated swim bladder (EC50) were 4.9 μg phenanthrene L -1 , 21.8 μg naphthalene L -1 , and 34.1 μg chrysene L -1 . This study shows that PAHs in ESFs from gas stations oil water separators are toxic to zebrafish, contributing to the toxicity of urban storm waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Assessment of Jatropha curcas L. biodiesel seed cake toxicity using the zebrafish (Danio rerio) embryo toxicity (ZFET) test.

    Hallare, Arnold V; Ruiz, Paulo Lorenzo S; Cariño, J C Earl D

    2014-05-01

    Consequent to the growing demand for alternative sources of energy, the seeds from Jatropha curcas remain to be the favorite for biodiesel production. However, a significant volume of the residual organic mass (seed cake) is produced during the extraction process, which raises concerns on safe waste disposal. In the present study, we assessed the toxicity of J. curcas seed cake using the zebrafish (Danio rerio) embryotoxicity test. Within 1-h post-fertilization (hpf), the fertilized eggs were exposed to five mass concentrations of J. curcas seed cake and were followed through 24, 48, and 72 hpf. Toxicity was evaluated based on lethal endpoints induced on zebrafish embryos namely egg coagulation, non-formation of somites, and non-detachment of tail. The lowest concentration tested, 1 g/L, was not able to elicit toxicity on embryos whereas 100 % mortality (based also on lethal endpoints) was recorded at the highest concentration at 2.15 g/L. The computed LC50 for the J. curcas seed cake was 1.61 g/L. No further increase in mortality was observed in the succeeding time points (48 and 72 hpf) indicating that J. curcas seed cake exerted acute toxicity on zebrafish embryos. Sublethal endpoints (yolk sac and pericardial edema) were noted at 72 hpf in zebrafish embryos exposed to higher concentrations. The observed lethal endpoints induced on zebrafish embryos were discussed in relation to the active principles, notably, phorbol esters that have remained in the seed cake even after extraction.

  20. Effects of dietary uranium on reproductive endpoints--fecundity, survival, reproductive success--of the fish Danio rerio.

    Simon, Olivier; Mottin, Elmina; Geffroy, Benjamin; Hinton, Thomas

    2011-01-01

    Exposure to metal-contaminated water has been shown to result in a number of reproductive abnormalities in adult and larvae fish, such as failure of oocyte maturation and teratogenic effects. Recently, dietary uptake of metals by fish has been recognized as a critical route of exposure, however, the mechanisms of metal uptake and toxicity are poorly understood and in need of further investigation. The objectives of the present study are to quantify uranium (U dietary transfers from spiked artificial diets) in Danio rerio tissues and embryos, as well as establish its effect on reproduction and embryonic development. Uranium's environmental prominence is currently increasing because of new mining and milling activities. Uranium concentrations range from 0.02 µg/L in natural waters to 2 mg/L. The focus of this study was to examine the trophic transfer and effects of U following exposure modalities (dose, exposure duration 1 to 20 d). Two different isotopes were used to distinguish between chemical and radioactivity toxicity of U. Results showed that U trophic transfer was low (0.52%). Uranium tissue distributions showed that accumulation occurred in digestive organs (liver, digestive tract) following dietary exposure. High levels of U were measured in the gonads (female in particular, >20% of relative burden). High U accumulation levels in eggs indicated maternal transfer of the contaminant. Moreover, U trophic exposure led to a reduction in reproduction success as a function of U accumulated levels. High U exposure conditions strongly reduced the total number of eggs (50%) and their viability at 10 d (reduction of the clutch number, low quality of eggs). © 2010 SETAC.

  1. Reversibility of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the estrogen 17α-ethinylestradiol

    Baumann, Lisa, E-mail: lisa.baumann@vetsuisse.unibe.ch [Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, PO Box 8466, CH-3001 Bern (Switzerland); Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Knörr, Susanne, E-mail: susanne.knoerr@gmx.de [Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Keiter, Susanne, E-mail: susanne.keiter@cos.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Rehberger, Kristina, E-mail: k.rehberger@stud.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Volz, Sina, E-mail: s.volz@stud.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Schiller, Viktoria, E-mail: schiller@molbiotech.rwth-aachen.de [Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstr. 6, D-52074 Aachen (Germany); Fenske, Martina, E-mail: martina.fenske@ime.fraunhofer.de [Fraunhofer Institute for Molecular Biology and Applied Ecology, Forckenbeckstr. 6, D-52074 Aachen (Germany); Holbech, Henrik, E-mail: hol@biology.sdu.dk [Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Segner, Helmut, E-mail: helmut.segner@vetsuisse.unibe.ch [Centre for Fish and Wildlife Health, Vetsuisse Faculty, University of Bern, PO Box 8466, CH-3001 Bern (Switzerland); Braunbeck, Thomas, E-mail: braunbeck@uni-hd.de [Aquatic Ecology and Toxicology Section, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany)

    2014-08-01

    The aim of the present study was to investigate the persistence of the feminizing effects of discontinued 17α-ethinylestradiol (EE2) exposure on zebrafish (Danio rerio). An exposure scenario covering the sensitive phase of sexual differentiation, as well as final gonad maturation was chosen to examine the estrogenic effects on sexual development of zebrafish. Two exposure scenarios were compared: continuous exposure to environmentally relevant concentrations (0.1–10 ng/L EE2) up to 100 days post-hatch (dph) and developmental exposure up to 60 dph, followed by 40 days of depuration in clean water. The persistence of effects was investigated at different biological organization levels from mRNA to population-relevant endpoints to cover a broad range of important parameters. EE2 had a strong feminizing and inhibiting effect on the sexual development of zebrafish. Brain aromatase (cyp19b) mRNA expression showed no clear response, but vitellogenin levels were significantly elevated, gonad maturation and body growth were inhibited in both genders, and sex ratios were skewed towards females and undifferentiated individuals. To a large extent, all of these effects were reversed after 40 days of recovery, leading to the conclusion that exposure to the estrogen EE2 results in very strong, but reversible underdevelopment and feminization of zebrafish. The present study is the first to show this reversibility at different levels of organization, which gives better insight into the mechanistic basis of estrogenic effects in zebrafish. - Highlights: • Zebrafish were exposed to 17α-ethinylestradiol during their sexual differentiation. • Reversibility of effects was investigated after depuration of 40 days. • Morphological and physiological parameters were compared. • Zebrafish were able to recover at all different levels from mRNA to population.

  2. Tributyltin induces premature hatching and reduces locomotor activity in zebrafish (Danio rerio) embryos/larvae at environmentally relevant levels.

    Liang, Xuefang; Souders, Christopher L; Zhang, Jiliang; Martyniuk, Christopher J

    2017-12-01

    Tributyltin (TBT) is an organotin compound that is the active ingredient of many biocides and antifouling agents. In addition to its well established role as an endocrine disruptor, TBT is also associated with adverse effects on the nervous system and behavior. In this study, zebrafish (Danio rerio) embryos were exposed to environmentally relevant concentrations of TBT (0.01, 0.1, 1 nM) to determine how low levels affected development and behavior. Fish exposed to 1 nM TBT hatched earlier when compared to controls. Following a 96-h exposure, total swimming distance, velocity, and activity of zebrafish larvae were reduced compared to controls. To identify putative mechanisms for these altered endpoints, we assessed embryo bioenergetics and gene expression. We reasoned that the accelerated hatch time could be related to ATP production and energy, thus embryos were exposed to TBT for 24 and 48-h exposure prior to hatch. There were no differences among groups for endpoints related to bioenergetics (i.e. basal, ATP-dependent, and maximal respiration). To address mechanisms related to changes in behavioral activity, we measured transcripts associated with muscle function (myf6, myoD, and myoG) and dopamine signaling (th, dat, dopamine receptors) as dopamine regulates behavior. No transcript was altered in expression by TBT in larvae, suggesting that other mechanisms exist that may explain changes in higher level endpoints. These results suggest that endpoints related to the whole animal (i.e. timing of hatch and locomotor behavior) are more sensitive to environmentally-relevant concentrations of TBT compared to the molecular and metabolic endpoints examined here. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Biodistribution and toxicological study of PEGylated single-wall carbon nanotubes in the zebrafish (Danio rerio) nervous system

    Weber, Gisele E.B.; Dal Bosco, Lidiane [Laboratório de Neurociências, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, 96210-900 (Brazil); Programa de Pós-graduação em Ciências Fisiológicas–Fisiologia Animal Comparada, FURG, Rio Grande, RS, 96210-900 (Brazil); Gonçalves, Carla O.F.; Santos, Adelina P. [Laboratório de Química de Nanoestruturas, Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, MG, 31270-901 (Brazil); Fantini, Cristiano [Instituto de Ciências Exatas, Departamento de Física, Belo Horizonte, MG, 31270-901 (Brazil); Furtado, Clascídia A. [Laboratório de Química de Nanoestruturas, Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, MG, 31270-901 (Brazil); Parfitt, Gustavo M.; Peixoto, Carolina [Laboratório de Neurociências, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, 96210-900 (Brazil); Programa de Pós-graduação em Ciências Fisiológicas–Fisiologia Animal Comparada, FURG, Rio Grande, RS, 96210-900 (Brazil); Romano, Luis Alberto [Instituto de Oceanografía, Universidade Federal do Rio Grande, Rio Grande, RS, 96210-030 (Brazil); and others

    2014-11-01

    Nanotechnology has been proven to be increasingly compatible with pharmacological and biomedical applications. Therefore, we evaluated the biological interactions of single-wall carbon nanotubes functionalized with polyethylene glycol (SWNT-PEG). For this purpose, we analyzed biochemical, histological, behavioral and biodistribution parameters to understand how this material behaves in vitro and in vivo using the fish Danio rerio (zebrafish) as a biological model. The in vitro results for fish brain homogenates indicated that SWNT-PEG had an effect on lipid peroxidation and GSH (reduced glutathione) content. However, after intraperitoneal exposure, SWNT-PEG proved to be less biocompatible and formed aggregates, suggesting that the PEG used for the nanoparticle functionalization was of an inappropriate size for maintaining product stability in a biological environment. This problem with functionalization may have contributed to the low or practically absent biodistribution of SWNT-PEG in zebrafish tissues, as verified by Raman spectroscopy. There was an accumulation of material in the abdominal cavity that led to inflammation and behavioral disturbances, as evaluated by a histological analysis and an open field test, respectively. These results provide evidence of a lack of biocompatibility of SWNTs modified with short chain PEGs, which leads to the accumulation of the material, tissue damage and behavioral alterations in the tested subjects. - Highlights: • In vitro brain exposure diminished lipid peroxidation. • In vitro brain exposure depletes the GSH content. • SWNT-PEG was not biocompatible and formed aggregates after the exposure. • Practically absent biodistribution of SWNT-PEG was observed by Raman spectroscopy. • SWNT-PEG exposure lead to tissue damage and inflammatory responses.

  4. The paracrine effect of exogenous growth hormone alleviates dysmorphogenesis caused by tbx5 deficiency in zebrafish (Danio rerio embryos

    Tsai Tzu-Chun

    2012-07-01

    Full Text Available Abstract Background Dysmorphogenesis and multiple organ defects are well known in zebrafish (Danio rerio embryos with T-box transcription factor 5 (tbx5 deficiencies, mimicking human Holt-Oram syndrome. Methods Using an oligonucleotide-based microarray analysis to study the expression of special genes in tbx5 morphants, we demonstrated that GH and some GH-related genes were markedly downregulated. Zebrafish embryos microinjected with tbx5-morpholino (MO antisense RNA and mismatched antisense RNA in the 1-cell stage served as controls, while zebrafish embryos co-injected with exogenous growth hormone (GH concomitant with tbx5-MO comprised the treatment group. Results The attenuating effects of GH in tbx5-MO knockdown embryos were quantified and observed at 24, 30, 48, 72, and 96 h post-fertilization. Though the understanding of mechanisms involving GH in the tbx5 functioning complex is limited, exogenous GH supplied to tbx5 knockdown zebrafish embryos is able to enhance the expression of downstream mediators in the GH and insulin-like growth factor (IGF-1 pathway, including igf1, ghra, and ghrb, and signal transductors (erk1, akt2, and eventually to correct dysmorphogenesis in various organs including the heart and pectoral fins. Supplementary GH also reduced apoptosis as determined by a TUNEL assay and decreased the expression of apoptosis-related genes and proteins (bcl2 and bad according to semiquantitative reverse-transcription polymerase chain reaction and immunohistochemical analysis, respectively, as well as improving cell cycle-related genes (p27 and cdk2 and cardiomyogenetic genes (amhc, vmhc, and cmlc2. Conclusions Based on our results, tbx5 knockdown causes a pseudo GH deficiency in zebrafish during early embryonic stages, and supplementation of exogenous GH can partially restore dysmorphogenesis, apoptosis, cell growth inhibition, and abnormal cardiomyogenesis in tbx5 knockdown zebrafish in a paracrine manner.

  5. Targeted Mutagenesis of the Hypophysiotropic Gnrh3 in Zebrafish (Danio rerio Reveals No Effects on Reproductive Performance.

    Olivia Smith Spicer

    Full Text Available Gnrh is the major neuropeptide regulator of vertebrate reproduction, triggering a cascade of events in the pituitary-gonadal axis that result in reproductive competence. Previous research in mice and humans has demonstrated that Gnrh/GNRH null mutations result in hypogonadotropic hypogonadism and infertility. The goal of this study was to eliminate gnrh3 (the hypophysiotropic Gnrh form function in zebrafish (Danio rerio to determine how ontogeny and reproductive performance are affected, as well as factors downstream of Gnrh3 along the reproductive axis. Using the TALEN technology, we developed a gnrh3-/- zebrafish line that harbors a 62 bp deletion in the gnrh3 gene. Our gnrh3-/- zebrafish line represents the first targeted and heritable mutation of a Gnrh isoform in any organism. Using immunohistochemistry, we verified that gnrh3-/- fish do not possess Gnrh3 peptide in any regions of the brain. However, other than changes in mRNA levels of pituitary gonadotropin genes (fshb, lhb, and cga during early development, which are corrected by adulthood, there were no changes in ontogeny and reproduction in gnrh3-/- fish. The gnrh3-/- zebrafish are fertile, displaying normal gametogenesis and reproductive performance in males and females. Together with our previous results that Gnrh3 cell ablation causes infertility, these results indicate that a compensatory mechanism is being activated, which is probably primed early on upon Gnrh3 neuron differentiation and possibly confined to Gnrh3 neurons. Potential compensation factors and sensitive windows of time for compensation during development and puberty should be explored.

  6. Development of molecular markers for zebrafish (Danio rerio) ovarian follicle growth assessment following in-vitro culture in cryopreservation studies.

    Anil, Siji; Rawson, David; Zhang, Tiantian

    2018-05-29

    Development of in vitro culture protocol for early stage ovarian follicles of zebrafish is important since cryopreserved early stage ovarian follicles would need to be matured in vitro following cryopreservation before they can be fertilised. Development of molecular markers for zebrafish (Danio rerio) ovarian follicle growth assessment following in vitro culture of early stage zebrafish ovarian follicles in ovarian tissue fragments is reported here for the first time although some work has been reported for in vitro culture of isolated early stage zebrafish ovarian follicles. The main aim of the present study was to develop molecular markers in an optimised in vitro culture protocol for stage I and stage II zebrafish ovarian follicles in ovarian tissue fragments. The effect of concentration of the hormones human chorionic gonadotropin and follicle stimulating hormones, and additives such as Foetal Bovine Serum and Bovine Serum Albumin were studied. The results showed that early stage zebrafish ovarian fragments containing stage I and stage II follicles which are cultured in vitro for 24 h in 20% FBS and 100mIU/ml FSH in 90% L-15 medium at 28 °C can grow to the size of stage II and stage III ovarian follicles respectively. More importantly the follicle growth from stage I to stage II and from stage II to stage III were confirmed using molecular markers such as cyp19a1a (also known as P450aromA) and vtg1 genes respectively. However, no follicle growth was observed following cryopreservation and in vitro culture. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Reversibility of endocrine disruption in zebrafish (Danio rerio) after discontinued exposure to the estrogen 17α-ethinylestradiol

    Baumann, Lisa; Knörr, Susanne; Keiter, Susanne; Rehberger, Kristina; Volz, Sina; Schiller, Viktoria; Fenske, Martina; Holbech, Henrik; Segner, Helmut; Braunbeck, Thomas

    2014-01-01

    The aim of the present study was to investigate the persistence of the feminizing effects of discontinued 17α-ethinylestradiol (EE2) exposure on zebrafish (Danio rerio). An exposure scenario covering the sensitive phase of sexual differentiation, as well as final gonad maturation was chosen to examine the estrogenic effects on sexual development of zebrafish. Two exposure scenarios were compared: continuous exposure to environmentally relevant concentrations (0.1–10 ng/L EE2) up to 100 days post-hatch (dph) and developmental exposure up to 60 dph, followed by 40 days of depuration in clean water. The persistence of effects was investigated at different biological organization levels from mRNA to population-relevant endpoints to cover a broad range of important parameters. EE2 had a strong feminizing and inhibiting effect on the sexual development of zebrafish. Brain aromatase (cyp19b) mRNA expression showed no clear response, but vitellogenin levels were significantly elevated, gonad maturation and body growth were inhibited in both genders, and sex ratios were skewed towards females and undifferentiated individuals. To a large extent, all of these effects were reversed after 40 days of recovery, leading to the conclusion that exposure to the estrogen EE2 results in very strong, but reversible underdevelopment and feminization of zebrafish. The present study is the first to show this reversibility at different levels of organization, which gives better insight into the mechanistic basis of estrogenic effects in zebrafish. - Highlights: • Zebrafish were exposed to 17α-ethinylestradiol during their sexual differentiation. • Reversibility of effects was investigated after depuration of 40 days. • Morphological and physiological parameters were compared. • Zebrafish were able to recover at all different levels from mRNA to population

  8. Monitoring Toxic Ionic Liquids in Zebrafish ( Danio rerio) with Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI)

    Perez, Consuelo J.; Tata, Alessandra; de Campos, Michel L.; Peng, Chun; Ifa, Demian R.

    2017-06-01

    Ambient mass spectrometry imaging has become an increasingly powerful technique for the direct analysis of biological tissues in the open environment with minimal sample preparation and fast analysis times. In this study, we introduce desorption electrospray ionization mass spectrometry imaging (DESI-MSI) as a novel, rapid, and sensitive approach to localize the accumulation of a mildly toxic ionic liquid (IL), AMMOENG 130 in zebrafish ( Danio rerio). The work demonstrates that DESI-MSI has the potential to rapidly monitor the accumulation of IL pollutants in aquatic organisms. AMMOENG 130 is a quaternary ammonium-based IL reported to be broadly used as a surfactant in commercialized detergents. It is known to exhibit acute toxicity to zebrafish causing extensive damage to gill secondary lamellae and increasing membrane permeability. Zebrafish were exposed to the IL in a static 96-h exposure study in concentrations near the LC50 of 1.25, 2.5, and 5.0 mg/L. DESI-MS analysis of zebrafish gills demonstrated the appearance of a dealkylated AMMOENG 130 metabolite in the lowest concentration of exposure identified by a high resolution hybrid LTQ-Orbitrap mass spectrometer as the trimethylstearylammonium ion, [C21H46N]+. With DESI-MSI, the accumulation of AMMOENG 130 and its dealkylated metabolite in zebrafish tissue was found in the nervous and respiratory systems. AMMOENG 130 and the metabolite were capable of penetrating the blood brain barrier of the fish with significant accumulation in the brain. Hence, we report for the first time the simultaneous characterization, distribution, and metabolism of a toxic IL in whole body zebrafish analyzed by DESI-MSI. This ambient mass spectrometry imaging technique shows great promise for the direct analysis of biological tissues to qualitatively monitor foreign, toxic, and persistent compounds in aquatic organisms from the environment. [Figure not available: see fulltext.

  9. The effects of dietary iron concentration on gastrointestinal and branchial assimilation of both iron and cadmium in zebrafish (Danio rerio)

    Cooper, C.A. [Division of Health and Life Sciences, King' s College London, 150 Stamford Street, London SE1 9NN (United Kingdom)]. E-mail: chris.cooper@ex.ac.uk; Handy, R.D. [School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Bury, N.R. [Division of Health and Life Sciences, King' s College London, 150 Stamford Street, London SE1 9NN (United Kingdom)

    2006-08-23

    Zebrafish (Danio rerio) were fed either a diet containing 33 mg Fe kg{sup -1} (low) or 95 mg Fe kg{sup -1} (normal) for 10 weeks, after which short-term Cd and Fe uptake by the gastrointestinal tract and gill was assessed. Carcass metal content and transcript levels of the iron importer, Divalent Metal Transporter 1 (DMT1) and an iron exporter, ferroportin1, in both the gastrointestinal tract and gill were also measured. Fish fed the low Fe diet accumulated 13 times more Cd into their livers via the gastrointestinal tract than those fed the normal Fe diet. However, no significant increase in liver Fe accumulation was measured. Concomitantly, when exposed to 48 nmol Cd L{sup -1} fish fed the low Fe diet exhibited a {approx}4-fold increase in Cd accumulation on the gill and in the liver, compared to those fed a normal diet. In addition, fish fed the low Fe diet also significantly accumulated more Fe on the gill (nine-fold increase) and into the carcass (four-fold increase) when exposed to 96 nmol Fe L{sup -1}, compared to fish fed a normal diet. Surprisingly, carcass Fe, Ca and Mg concentrations were increased in fish fed the low Fe diet, which suggests that Fe body levels may not be a good indicator of whether a fish is more or less susceptible to increased non-essential metal accumulation via an Fe uptake pathway. However, significantly elevated transcript levels of DMT1 and ferroportin1 (2.7- and 3.8-fold induction, respectively) were seen in the gastrointestinal tract, and DMT1 in the gills (1.8-fold induction) of zebrafish fed a low Fe diet. The correlation between Cd uptake and DMT1 expression suggests that one route of uptake of Cd, either from the diet or from the water, could be via DMT1.

  10. Cadmium stress assessment based on the electrocardiogram characteristics of zebra fish (Danio rerio): QRS complex could play an important role.

    Xing, Na; Ji, Lizhen; Song, Jie; Ma, Jingchun; Li, Shangge; Ren, Zongming; Xu, Fei; Zhu, Jianping

    2017-10-01

    The electrocardiogram (ECG) of zebra fish (Danio rerio) expresses cardiac features that are similar to humans. Here we use sharp microelectrode measurements to obtain ECG characteristics in adult zebra fish and analyze the effects of cadmium chloride (CdCl 2 ) on the heart. We observe the overall changes of ECG parameters in different treatments (0.1 TU, 0.5 TU and 1.0 TU CdCl 2 ), including P wave, Q wave, R wave, S wave, T wave, PR interval (atrial contraction), QRS complex (ventricular depolarization), ST segment, and QT interval (ventricular repolarization). The trends of the ECG parameters showed some responses to the concentration and exposure time of CdCl 2 , but it was difficult to obtain more information about the useful indicators in water quality assessment depending on tendency analysis alone. A self-organizing map (SOM) showed that P values, R values, and T values were similar; R wave and T wave amplitude were similar; and most important, QRS value was similar to the CdCl 2 stress according to the classified data patterns including CdCl 2 stress (E) and ECG components based on the Ward linkage. It suggested that the duration of QRS complex was related to environmental stress E directly. The specification and evaluation of ECG parameters in Cd 2+ pollution suggested that there is a markedly significant correlation between QRS complex and CdCl 2 stress with the highest r (0.729) and the smallest p (0.002) among all ECG characteristics. In this case, it is concluded that QRS complex can be used as an indicator in the CdCl 2 stress assessment due to the lowest AIC data abased on the linear regression model between the CdCl 2 stress and ECG parameters. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. In silico and in situ characterization of the zebrafish (Danio rerio gnrh3 (sGnRH gene

    Husebye Harald

    2002-08-01

    Full Text Available Abstract Background Gonadotropin releasing hormone (GnRH is responsible for stimulation of gonadotropic hormone (GtH in the hypothalamus-pituitary-gonadal axis (HPG. The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio. Results We have characterized a zebrafish [Trp7, Leu8] or salmon (s GnRH variant, gnrh3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH, was shown capable of driving cell specific reporter gene expression in transgenic zebrafish. Conclusions The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.

  12. Biodistribution and toxicological study of PEGylated single-wall carbon nanotubes in the zebrafish (Danio rerio) nervous system

    Weber, Gisele E.B.; Dal Bosco, Lidiane; Gonçalves, Carla O.F.; Santos, Adelina P.; Fantini, Cristiano; Furtado, Clascídia A.; Parfitt, Gustavo M.; Peixoto, Carolina; Romano, Luis Alberto

    2014-01-01

    Nanotechnology has been proven to be increasingly compatible with pharmacological and biomedical applications. Therefore, we evaluated the biological interactions of single-wall carbon nanotubes functionalized with polyethylene glycol (SWNT-PEG). For this purpose, we analyzed biochemical, histological, behavioral and biodistribution parameters to understand how this material behaves in vitro and in vivo using the fish Danio rerio (zebrafish) as a biological model. The in vitro results for fish brain homogenates indicated that SWNT-PEG had an effect on lipid peroxidation and GSH (reduced glutathione) content. However, after intraperitoneal exposure, SWNT-PEG proved to be less biocompatible and formed aggregates, suggesting that the PEG used for the nanoparticle functionalization was of an inappropriate size for maintaining product stability in a biological environment. This problem with functionalization may have contributed to the low or practically absent biodistribution of SWNT-PEG in zebrafish tissues, as verified by Raman spectroscopy. There was an accumulation of material in the abdominal cavity that led to inflammation and behavioral disturbances, as evaluated by a histological analysis and an open field test, respectively. These results provide evidence of a lack of biocompatibility of SWNTs modified with short chain PEGs, which leads to the accumulation of the material, tissue damage and behavioral alterations in the tested subjects. - Highlights: • In vitro brain exposure diminished lipid peroxidation. • In vitro brain exposure depletes the GSH content. • SWNT-PEG was not biocompatible and formed aggregates after the exposure. • Practically absent biodistribution of SWNT-PEG was observed by Raman spectroscopy. • SWNT-PEG exposure lead to tissue damage and inflammatory responses

  13. Effects of nickel chloride and oxygen depletion on behaviour and vitality of zebrafish (Danio rerio, Hamilton, 1822) (Pisces, Cypriniformes) embryos and larvae

    Kienle, Cornelia; Koehler, H.-R.; Filser, Juliane; Gerhardt, Almut

    2008-01-01

    We examined acute (2 h exposure of 5-day-old larvae) and subchronic (exposure from fertilization up to an age of 11 days) effects of NiCl 2 .6H 2 O on embryos and larvae of zebrafish (Danio rerio), both alone and in combination with oxygen depletion. The following endpoints were recorded: acute exposure: locomotory activity and survival; subchronic exposure: hatching rate, deformations, locomotory activity (at 5, 8 and 11 days) and mortality. In acute exposures nickel chloride (7.5-15 mg Ni/L) caused decreasing locomotory activity. Oxygen depletion (≤2.45 ± 0.16 mg O 2 /L) also resulted in significantly reduced locomotory activity. In the subchronic test, exposure to ≥10 mg Ni/L resulted in delayed hatching at an age of 96 h, in decreased locomotory activity at an age of 5 days, and increased mortality at an age of 11 days (LC 20 = 9.5 mg Ni/L). The observed LOEC for locomotory activity (7.5 mg Ni/L) is in the range of environmentally relevant concentrations. Since locomotory activity was already affected by acute exposure, this parameter is recommended to supplement commonly recorded endpoints of toxicity. - Increasing concentrations of nickel chloride and decreasing concentrations of oxygen lead to reduced vitality and locomotory activity in Danio rerio embryos and larvae

  14. Development of a new screening assay to identify proteratogenic substances using zebrafish danio rerio embryo combined with an exogenous mammalian metabolic activation system (mDarT).

    Busquet, François; Nagel, Roland; von Landenberg, Friedrich; Mueller, Stefan O; Huebler, Nicole; Broschard, Thomas H

    2008-07-01

    The assessment of teratogenic effects of chemicals is generally performed using in vivo teratogenicity assays, for example, in rats or rabbits. We have developed an in vitro teratogenicity assay using the zebrafish Danio rerio embryo combined with an exogenous mammalian metabolic activation system (MAS), able to biotransform proteratogenic compounds. Cyclophosphamide (CPA) and ethanol were used as proteratogens to test the efficiency of this assay. Briefly, the zebrafish embryos were cocultured at 2 hpf (hours postfertilization) with the test material at varying concentrations, induced male rat liver microsomes and nicotinamide adenine dinucleotide phosphate (reduced) for 60 min at 32 degrees C under moderate agitation in Tris-buffer. The negative control (test material alone) and the MAS control (MAS alone) were incubated in parallel. For each test group, 20 eggs were used for statistical robustness. Afterward fish embryos were transferred individually into 24-well plates filled with fish medium for 48 h at 26 degrees C with a 12-h light cycle. Teratogenicity was scored after 24 and 48 hpf using morphological endpoints. No teratogenic effects were observed in fish embryos exposed to the proteratogens alone, that is, without metabolic activation. In contrast, CPA and ethanol induced abnormalities in fish embryos when coincubated with microsomes. The severity of malformations increased with increasing concentrations of the proteratogens. We conclude that the application of microsomes will improve and refine the D. rerio teratogenicity assay as a predictive and valuable alternative method to screen teratogenic substances.

  15. Histopathological alterations and induction of hsp70 in ramshorn snail (Marisa cornuarietis) and zebrafish (Danio rerio) embryos after exposure to PtCl(2).

    Osterauer, Raphaela; Köhler, Heinz-R; Triebskorn, Rita

    2010-08-01

    The platinum group metals (PGMs) platinum (Pt), palladium (Pd), and rhodium (Rh) are used in automobile catalytic converters, from which they have been emitted into the environment to an increasing degree during the last 20 years. Despite the bioavailability of these metals to plants and animals, studies determining the effects of PGMs on organisms are extremely rare. In the present study, effects of various concentrations of PtCl(2) (0.1, 1, 10, 50 and 100 microg/L) were investigated with respect to the induction of hsp70 and histopathological alterations in the zebrafish, Danio rerio and the ramshorn snail, Marisa cornuarietis. Histopathological investigations revealed effects of Pt on both species, which varied between slight and strong cellular reactions, depending on the PtCl(2) concentration. The hsp70 level in M. cornuarietis did not show an increase following Pt exposure whereas it was significantly elevated at 100 micorg/L PtCl(2) in D. rerio. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Cathepsin activities and membrane integrity of zebrafish (Danio rerio) oocytes after freezing to -196 degrees C using controlled slow cooling.

    Zhang, T; Rawson, D M; Tosti, L; Carnevali, O

    2008-04-01

    This study investigated enzymatic activity of cathepsins and the membrane integrity of zebrafish (Danio rerio) oocytes after freezing to -196 degrees C using controlled slow cooling. Stage III oocytes (>0.5mm), obtained through dissection of anaesthetised female fish and desegregation of ovarian cumulus, were exposed to 2M methanol or 2M DMSO (both prepared in Hank's medium) for 30min at 22 degrees C before being loaded into 0.5ml plastic straws and placed into a programmable cooler. After controlled slow freezing, samples were plunged into liquid nitrogen (LN) and held for at least 10min, and thawed by immersing straws into a 27 degrees C water bath for 10s. Thawed oocytes were washed twice in Hank's medium. Cathepsin activity and membrane integrity of oocytes were assessed both after cryoprotectant treatment at 22 degrees C and after freezing in LN. Cathepsin B and L colorimetric analyses were performed using substrates Z-Arg-ArgNNap and Z-Phe-Arg-4MbetaNA-HCl, respectively, and 2-naphthylamine and 4-methoxy-2-naphthylamine were used as standards. Cathepsin D activity was performed by analysing the level of hydrolytic action on haemoglobin. Oocytes membrane integrity was assessed using 0.2% Trypan blue staining for 5min. Analysis of cathepsin activities showed that whilst the activity of cathepsin B and D was not affected by 2M DMSO treatment, their activity was lowered when treated with 2M methanol. Following freezing to -196 degrees C, the activity of all cathepsins (B, D and L) was significantly decreased in both 2M DMSO and 2M methanol. Trypan blue staining showed that 63.0+/-11.3% and 72.7+/-5.2% oocytes membrane stayed intact after DMSO and methanol treatment for 30min at 22 degrees C, respectively, whilst 14.9+/-2.6% and 1.4+/-0.8% stayed intact after freezing in DMSO and methanol to -196 degrees C. The results indicate that cryoprotectant treatment and freezing modified the activities of lysosomal enzymes involved in oocyte maturation and yolk

  17. Effects of depleted uranium on the reproductive success and F1 generation survival of zebrafish (Danio rerio)

    Bourrachot, Stéphanie [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Brion, François [Institut National de l’Environnement Industriel et des Risques (INERIS), Unité d’évaluation des risques écotoxicologiques, BP2, 60550 Verneuil-en-Halatte (France); Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Cavalié, Isabelle [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Palluel, Olivier [Institut National de l’Environnement Industriel et des Risques (INERIS), Unité d’évaluation des risques écotoxicologiques, BP2, 60550 Verneuil-en-Halatte (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France)

    2014-09-15

    Highlights: • The effect of depleted uranium on zebrafish reproduction was studied. • An inhibition of egg production and an increase of F1 embryo mortality were observed. • Decreased circulating concentration of vitellogenin was observed in females. • Increased DNA damages were observed in parent gonads and in embryos. • U environmental concentration impairs reproduction and genetic integrity of fish. - Abstract: Despite the well-characterized occurrence of uranium (U) in the aquatic environment, very little is known about the chronic exposure of fish to low levels of U and its potential effect on reproduction. Therefore, this study was undertaken to investigate the effects of environmental concentrations of depleted U on the reproductive output of zebrafish (Danio rerio) and on survival and development of the F1 embryo-larvae following parental exposure to U. For that purpose, sexually mature male and female zebrafish were exposed to 20 and 250 μg/L of U for 14 days and allowed to reproduce in clean water during a further 14-day period. At all sampling times, whole-body vitellogenin concentrations and gonad histology were analyzed to investigate the effects of U exposure on these reproductive endpoints. In addition, accumulation of U in the gonads and its genotoxic effect on male and female gonad cells were quantified. The results showed that U strongly affected the capability of fish to reproduce and to generate viable individuals as evidenced by the inhibition of egg production and the increased rate of mortality of the F1 embryos. Interestingly, U exposure resulted in decreased circulating concentrations of vitellogenin in females. Increased concentrations of U were observed in gonads and eggs, which were most likely responsible for the genotoxic effects seen in fish gonads and in embryos exposed maternally to U. Altogether, these findings highlight the negative effect of environmentally relevant concentrations of U which alter the reproductive

  18. Inward rectifier potassium current (I K1) and Kir2 composition of the zebrafish (Danio rerio) heart.

    Hassinen, Minna; Haverinen, Jaakko; Hardy, Matt E; Shiels, Holly A; Vornanen, Matti

    2015-12-01

    Electrophysiological properties and molecular background of the zebrafish (Danio rerio) cardiac inward rectifier current (IK1) were examined. Ventricular myocytes of zebrafish have a robust (-6.7 ± 1.2 pA pF(-1) at -120 mV) strongly rectifying and Ba(2+)-sensitive (IC50 = 3.8 μM) IK1. Transcripts of six Kir2 channels (drKir2.1a, drKir2.1b, drKir2.2a, drKir2.2b, drKir2.3, and drKir2.4) were expressed in the zebrafish heart. drKir2.4 and drKir2.2a were the dominant isoforms in both the ventricle (92.9 ± 1.5 and 6.3 ± 1.5%) and the atrium (28.9 ± 2.9 and 64.7 ± 3.0%). The remaining four channels comprised together less than 1 and 7 % of the total transcripts in ventricle and atrium, respectively. The four main gene products (drKir2.1a, drKir2.2a, drKir2.2b, drKir2.4) were cloned, sequenced, and expressed in HEK cells for electrophysiological characterization. drKir2.1a was the most weakly rectifying (passed more outward current) and drKir2.2b the most strongly rectifying (passed less outward current) channel, whilst drKir2.2a and drKir2.4 were intermediate between the two. In regard to sensitivity to Ba(2+) block, drKir2.4 was the most sensitive (IC50 = 1.8 μM) and drKir2.1a the least sensitive channel (IC50 = 132 μM). These findings indicate that the Kir2 isoform composition of the zebrafish heart markedly differs from that of mammalian hearts. Furthermore orthologous Kir2 channels (Kir2.1 and Kir2.4) of zebrafish and mammals show striking differences in Ba(2+)-sensitivity. Structural and functional differences needs to be taken into account when zebrafish is used as a model for human cardiac electrophysiology, cardiac diseases, and in screening cardioactive substances.

  19. Effects of depleted uranium on the reproductive success and F1 generation survival of zebrafish (Danio rerio)

    Bourrachot, Stéphanie; Brion, François; Pereira, Sandrine; Floriani, Magali; Camilleri, Virginie; Cavalié, Isabelle; Palluel, Olivier; Adam-Guillermin, Christelle

    2014-01-01

    Highlights: • The effect of depleted uranium on zebrafish reproduction was studied. • An inhibition of egg production and an increase of F1 embryo mortality were observed. • Decreased circulating concentration of vitellogenin was observed in females. • Increased DNA damages were observed in parent gonads and in embryos. • U environmental concentration impairs reproduction and genetic integrity of fish. - Abstract: Despite the well-characterized occurrence of uranium (U) in the aquatic environment, very little is known about the chronic exposure of fish to low levels of U and its potential effect on reproduction. Therefore, this study was undertaken to investigate the effects of environmental concentrations of depleted U on the reproductive output of zebrafish (Danio rerio) and on survival and development of the F1 embryo-larvae following parental exposure to U. For that purpose, sexually mature male and female zebrafish were exposed to 20 and 250 μg/L of U for 14 days and allowed to reproduce in clean water during a further 14-day period. At all sampling times, whole-body vitellogenin concentrations and gonad histology were analyzed to investigate the effects of U exposure on these reproductive endpoints. In addition, accumulation of U in the gonads and its genotoxic effect on male and female gonad cells were quantified. The results showed that U strongly affected the capability of fish to reproduce and to generate viable individuals as evidenced by the inhibition of egg production and the increased rate of mortality of the F1 embryos. Interestingly, U exposure resulted in decreased circulating concentrations of vitellogenin in females. Increased concentrations of U were observed in gonads and eggs, which were most likely responsible for the genotoxic effects seen in fish gonads and in embryos exposed maternally to U. Altogether, these findings highlight the negative effect of environmentally relevant concentrations of U which alter the reproductive

  20. Multiple TPR motifs characterize the Fanconi anemia FANCG protein.

    Blom, Eric; van de Vrugt, Henri J; de Vries, Yne; de Winter, Johan P; Arwert, Fré; Joenje, Hans

    2004-01-05

    The genome protection pathway that is defective in patients with Fanconi anemia (FA) is controlled by at least eight genes, including BRCA2. A key step in the pathway involves the monoubiquitylation of FANCD2, which critically depends on a multi-subunit nuclear 'core complex' of at least six FANC proteins (FANCA, -C, -E, -F, -G, and -L). Except for FANCL, which has WD40 repeats and a RING finger domain, no significant domain structure has so far been recognized in any of the core complex proteins. By using a homology search strategy comparing the human FANCG protein sequence with its ortholog sequences in Oryzias latipes (Japanese rice fish) and Danio rerio (zebrafish) we identified at least seven tetratricopeptide repeat motifs (TPRs) covering a major part of this protein. TPRs are degenerate 34-amino acid repeat motifs which function as scaffolds mediating protein-protein interactions, often found in multiprotein complexes. In four out of five TPR motifs tested (TPR1, -2, -5, and -6), targeted missense mutagenesis disrupting the motifs at the critical position 8 of each TPR caused complete or partial loss of FANCG function. Loss of function was evident from failure of the mutant proteins to complement the cellular FA phenotype in FA-G lymphoblasts, which was correlated with loss of binding to FANCA. Although the TPR4 mutant fully complemented the cells, it showed a reduced interaction with FANCA, suggesting that this TPR may also be of functional importance. The recognition of FANCG as a typical TPR protein predicts this protein to play a key role in the assembly and/or stabilization of the nuclear FA protein core complex.

  1. Chronotoxicity of contaminants (etanol and hezvy metales) in a freshwater teleost Dario rerio (Hamilton, 1882) and marine amphipods Gammarus aequicauda (Martynov, 1931) and Gammarus chevreuxi (Sexton, 1913) = Cronotixicidad de contaminantes (etanol y metales pesados) en el teleósteo de agua dulce Dario rerio (Hamilton, 1822) y los antípodos marinos, Gammarus aequicauda (Martynov, 1931) y Gammarus chevreuxi (Sexton, 1913)

    Bello Marín, Carolina

    2015-01-01

    Esta tesis tiene como objetivo investigar los efectos del etanol y metales pesados (cadmio y mercurio) en los patrones diarios de dos especies acuáticas clave: pez cebra (Darío rerio) y anfípodo gammarus (G. aequicauda y G. chevreuxi). La investigación se realizó en dos niveles organizativos: comportamental y molecular. Con este fin, hemos establecido cuatro objetivos específicos: 1. Investigar los efectos al etanol en el pez cebra en función en su ritmo circadiano. 2. Determinar la exi...

  2. Characterization of DNA polymerase β from Danio rerio by overexpression in E. coli using the in vivo/in vitro compatible pIVEX plasmid

    Ishikawa Mitsuru

    2011-10-01

    Full Text Available Abstract Background Eukaryotic DNA polymerase β (pol β, the polymerase thought to be responsible for DNA repair synthesis, has been extensively characterized in rats and humans. However, pol β has not been purified or enzymatically characterized from the model fish species Danio rerio (zebrafish. We used the in vitro/in vivo dual expression system plasmid, pIVEX, to express Danio rerio pol β (Danio pol β for biochemical characterization. Results Danio pol β encoded by the in vitro/in vivo-compatible pIVEX plasmid was expressed in E. coli BL21(DE3, BL21(DE3pLysS, and KRX, and in vitro as a C-terminal His-tagged protein. Danio pol β expressed in vitro was subject to proteolysis; therefore, bacterial overexpression was used to produce the protein for kinetic analyses. KRX cells were preferred because of their reduced propensity for leaky expression of pol β. The cDNA of Danio rerio pol β encodes a protein of 337 amino acids, which is 2-3 amino acids longer than other pol β proteins, and contains a P63D amino acid substitution, unlike mammalian pol βs. This substitution lies in a hairpin sequence within an 8-kDa domain, likely to be important in DNA binding. We performed extensive biochemical characterization of Danio pol β in comparison with rat pol β, which revealed its sensitivity to metal ion activators (Mn2+ and Mg2+, its optimum salt concentration (10 mM KCl and 50 mM NaCl, alkaline pH optimum (pH 9.0, and low temperature optimum (30°C. Substituting Mn2+ for Mg2+ resulted in 8.6-fold higher catalytic efficiency (kcat/Km. Conclusions Our characterization of pol β from a model fish organism contributes to the study of the function and evolution of DNA polymerases, which are emerging as important cellular targets for chemical intervention in the development of anticancer agents.

  3. In vitro cytotoxic and teratogenic potential of sediment extracts from Skadar Lake using fish cell line RTL-W1 and Danio rerio embryos

    Perović Andrej

    2013-01-01

    Full Text Available As a part of Sediment Quality Triad (SQT, organic extracts of sediment from Skadar Lake (a Mediterranean lake and the largest freshwater reservoir in southeastern Europe were investigated in order to evaluate possible ecotoxicological contamination by organic pollutants and to obtain a comprehensive insight into the ecotoxicological hazard. Sediments were investigated for toxicity by two different bioassays. Acute cytotoxicity was investigated using the fibroblast-like cell line RTL-W1 (Oncorhynchus mykiss in combination with the neutral red retention assay. The embryos of zebrafish (Danio rerio were used to assess the toxic and teratogenic potential of organic extracts of the sediment. Preliminary results point to the presence of a cytotoxic and teratogenic potential in Skadar Lake sediment extracts in certain locations.

  4. El pez cebra (Danio Rerio como modelo animal de sueño: Nadando en una nueva dirección

    Carlos del Río-Bermúdez

    2013-01-01

    Full Text Available A pesar de los esfuerzos por comprender los mecanismos fisiológicos y funciones del sueño, el por qué pasamos más de un tercio de nuestra vida durmiendo sigue siendo uno de los grandes misterios de la neurociencia actual. Sin embargo, el uso de nuevos modelos animales simples está generando novedosos e importantes resultados sobre aspectos genéticos, fisiológicos y conductuales del sueño. El pez cebra (Danio rerio constituye un modelo idóneo para el análisis del sueño a nivel sistémico y molecular, y sus características fisiológicas permiten la extrapolación de estos hallazgos a especies filogenéticamente superiores, como el ser humano.

  5. Sexual disruption in zebrafish (Danio rerio) exposed to mixtures of 17α-ethinylestradiol and 17β-trenbolone

    Örn, Stefan; Holbech, Henrik; Norrgren, Leif

    2016-01-01

    was to evaluate feminization and masculinization effects in zebrafish (Danio rerio) exposed to combinations of two synthetic steroid hormones detected in environmental waters: the androgen 17β-trenbolone (Tb) and the oestrogen 17α-ethinylestradiol (EE2). Juvenile zebrafish were exposed between days 20 and 60 post......Environmental estrogens and androgens can be present simultaneously in aquatic environments and thereby interact to disturb multiple physiological systems in organisms. Studies on interaction effects in fish of androgenic and estrogenic chemicals are limited. Therefore, the aim of the present study......-hatch to different binary mixtures of Tb (1, 10, and 50 ng/L) and EE2 (2 and 5 ng/L). The endpoints studied were whole-body homogenate vitellogenin concentration at 40 days post-hatch, and sex ratio including gonad maturation at 60 days post-hatch. The feminizing potency of 5 ng/L of EE2, alone as well...

  6. Cell phone-generated radio frequency electromagnetic field effects on the locomotor behaviors of the fishes Poecilia reticulata and Danio rerio.

    Lee, David; Lee, Joshua; Lee, Imshik

    2015-01-01

    The locomotor behavior of small fish was characterized under a cell phone-generated radio frequency electromagnetic field (RF EMF). The trajectory of movement of 10 pairs of guppy (Poecilia reticulate) and 15 pairs of Zebrafish (Danio rerio) in a fish tank was recorded and tracked under the presence of a cell phone-generated RF EMF. The measures were based on spatial and temporal distributions. A time-series trajectory was utilized to emphasize the dynamic nature of locomotor behavior. Fish movement was recorded in real-time. Their spatial, velocity, turning angle and sinuosity distribution were analyzed in terms of F(v,x), P[n(x,t)], P(v), F (θ) and F(s), respectively. In addition, potential temperature elevation caused by a cellular phone was also examined. We demonstrated that a cellular phone-induced temperature elevation was not relevant, and that our measurements reflected RF EMF-induced effects on the locomotor behavior of Poecilia reticulata and Danio rerio. Fish locomotion was observed under normal conditions, in the visual presence of a cell phone, after feeding, and under starvation. Fish locomotor behavior was random both in normal conditions and in the presence of an off-signaled cell phone. However, there were significant changes in the locomotion of the fish after feeding under the RF EMF. The locomotion of the fed fish was affected in terms of changes in population and velocity distributions under the presence of the RF EMF emitted by the cell phone. There was, however, no significant difference in angular distribution.

  7. Genotoxic effects and gene expression in Danio rerio (Hamilton 1822) (Cypriniformes: Cyprinidae) exposed to mining-impacted tributaries in Manizales, Colombia.

    Ossa-López, Paula A; Castaño-Villa, Gabriel J; Rivera-Páez, Fredy A

    2017-09-25

    The zebrafish (Danio rerio) is one of the most studied aquatic organisms for water biomonitoring, due to its sensitivity to environmental degradation and resistance to toxic substances. This study determined the presence of micronuclei and nuclear abnormalities in peripheral blood erythrocytes, and assessed the gene expression of caspase-3 (CASP-3) and metallothionein 1 (MT-1) in the gills and liver of D. rerio. The study fish (n = 45) were exposed to water collected from two stations with mining impact (E2 and E3) and a reference station without evident mining contamination (E1), all located in La Elvira stream (Manizales-Colombia). In addition, a positive control (PC) with HgCl 2 (50 μg/L) and negative control (NC) with tap water were included. The fish from the PC and E2 and E3 treatments displayed genotoxic effects and changes in gene expression, with significant differences in micronuclei formation and the presence of blebbed nuclei. The cytochrome oxidase subunit I (COI) gene was used as reference and proved to be stable compared to the β-actin and 28S ribosomal RNA (28S) genes. In gills, CASP-3 expression was higher in the PC, and MT-1 expression was higher in the PC and E3 treatment. In liver, CASP-3 was expressed in the E2 treatment, and MT-1 expression was low. These results show that the genotoxic effects and differential gene expression observed in fish exposed to water from La Elvira stream could also be affecting the organisms present in this habitat.

  8. Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development Metabolismo aeróbico e anaeróbico do paulistinha Danio rerio, mantidos sob normóxia e hipóxia moderada e expostos a hipóxia aguda durante diferentes estágios de desenvolvimento

    WR Barrionuevo

    2010-05-01

    Full Text Available In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2, critical tensions of oxygen (Pcrit, heart rate (fH and total body lactate concentration (Lc were determined for Danio rerio (Hamilton, 1822 raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1 and hypoxic conditions (4.3 mgO2.L-1 and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.A influência de diferentes níveis de oxigênio no desenvolvimento (ovos a adulto do peixe paulistinha Danio rerio (Hamilton, 1822 foi verificada por meio de medidas experimentais de consumo de oxigênio (MO2, tensões críticas de oxigênio (Pcrit, taxa de batimentos cardíacos (fH e concentração total de lactato nos tecidos (Lc, para os animais mantidos a 28 ºC sob níveis normóxicos de oxigênio (7.5 mgO2.L-1 ou 80 mmHg e hipóxicos (4.3 mgO2.L-1 e submetidos a hipóxia ambiental aguda, em diferentes estágios de desenvolvimento. Os

  9. Hepatic Proteomic Responses in Marine Medaka ( Oryzias melastigma ) Chronically Exposed to Antifouling Compound Butenolide [5-octylfuran-2(5H)-one] or 4,5-Dichloro-2- N -Octyl-4-Isothiazolin-3-One (DCOIT)

    Chen, Lianguo

    2015-02-03

    The pollution of antifoulant SeaNine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) as active ingredient, in coastal environment raises concerns on its adverse effects, including endocrine disruption and impairment of reproductive function in marine organisms. In the present study, we investigated the hepatic protein expression profiles of both male and female marine medaka (Oryzias melastigma) exposed to low concentrations of DCOIT at 2.55 mu g/L (0.009 mu M) or butenolide, a promising antifouling agent, at 2.31 mu g/L (0.012 mu M) for 28 days. The results showed that proteins involved in phase I (CYP450 enzyme) metabolism, phase II (UDPGT and GST) conjugation as well as mobilization of retinoid storage, an effective nonenzymatic antioxidant, were consistently up-regulated, possibly facilitating the accelerated detoxification of butenolide. Increased synthesis of bile acid would promote the immediate excretion of butenolide metabolites. Activation of fatty acid beta-oxidation and ATP synthesis were consistent with elevated energy consumption for butenolide degradation and excretion. However, DCOIT did not significantly affect the detoxification system of male medaka, but induced a marked increase of vitellogenin (VTG) by 2.3-fold in the liver of male medaka, suggesting that there is estrogenic activity of DCOIT in endocrine disruption. Overall, this study identified the molecular mechanisms and provided sensitive biomarkers characteristic of butenolide and DCOIT in the liver of marine medaka. The low concentrations of butenolide and DCOIT used in the exposure regimes highlight the needs for systematic evaluation of their environmental risk. In addition, the potent estrogenic activity of DCOIT should be considered in the continued applications of SeaNine 211.

  10. Proteomic changes in brain tissues of marine medaka (Oryzias melastigma) after chronic exposure to two antifouling compounds: Butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT)

    Chen, Lianguo

    2014-12-01

    SeaNine 211 with active ingredient of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) has been used as a "green" antifouling agent worldwide but has raised serious biosafety concerns in coastal environments. DCOIT has the potential to disrupt the neurotransmission in nervous system, but the underlying mechanism has not been clarified. In the present study, we used TMT six-plex labeling coupled with two-dimensional LC-MS/MS analysis to investigate the protein expression profiles in brain tissues of the marine medaka (Oryzias melastigma) after a 28-day exposure to environmentally-realistic concentration of DCOIT at 2.55. μg/L (0.009. μM) or butenolide, one promising antifouling compound, at 2.31. μg/L (0.012. μM). DCOIT and butenolide induced differential expression of 26 and 18 proteins in male brains and of 27 and 23 proteins in female brains, respectively. Distinct mechanisms of toxicity were initiated by DCOIT and butenolide in males, whereas the protein expression profiles were largely similar in females treated by these two compounds. In males, DCOIT exposure mainly led to disruption of mitogen-activated protein kinase (MAPK) signaling pathway, while butenolide affected proteins related to the cytoskeletal disorganization that is considered as a general response to toxicant stress. Furthermore, a sex-dependent protein expression profile was also noted between male and female fish, as evident by the inverse changes in the expressions of common proteins (5 proteins for butenolide- and 2 proteins for DCOIT-exposed fish). Overall, this study provided insight into the molecular mechanisms underlying the toxicity of DCOIT and butenolide. The extremely low concentrations used in this study highlighted the ecological relevance, arguing for thorough assessments of their ecological risks before the commercialization of any new antifouling compound.

  11. Comment: 198 [Taxonomy Icon

    Full Text Available ゲノム比較解析のためにゲノム解読が行われた。 撮影:成瀬清(基礎生物学研究所) Photo: Kiyoshi Naruse (National Institute for Basic Biology) bando 2009/10/01 14:48:45 2010/01/14 20:09:26 ... ...nal Institute for Basic Biology) licensed under CC Attribution2.1 Japan メダカ近交系 HNI-Ⅱ系統 北日本集団由来の純系。 Hd-rR系統との...Japanese medaka Oryzias latipes Oryzias_latipes_L.png 198.png Kiyoshi Naruse (Natio

  12. Comment: 199 [Taxonomy Icon

    Full Text Available nal Institute for Basic Biology) licensed under CC Attribution2.1 Japan メダカ近交系 Hd-rR系統 南日本集団由来の純系。 メダカで最初にゲノム解読が行われた系統。 撮影:成瀬清(基礎生物学...研究所) Photo: Kiyoshi Naruse (National Institute for Basic Biology) bando 2009/09/30 11:23:24 2010/01/14 20:09:43 ... ...Japanese medaka Oryzias latipes Oryzias_latipes_L.png 199.png Kiyoshi Naruse (Natio

  13. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrol...

  14. A comparative expression analysis of gene transcripts in brain tissue of non-transgenic and GH-transgenic zebrafish (Danio rerio using a DDRT-PCR approach

    Fernanda A. Alves-Costa

    2012-06-01

    Full Text Available The presence of higher level of exogenous growth hormone (GH in transgenic animals could lead to several physiological alterations. A GH transgenic zebrafish (Danio rerio line was compared to nontransgenic (NT samples of the species through a DDRT-PCR approach, with the goal of identifying candidate differentially expressed transcripts in brain tissues that could be involved in GH overexpression. Densitometric analyses of two selected amplification products, p300 and ADCY2, pointed to a significant lower gene expression in the transgenic zebrafish (104.02 ± 57.71; 224.10 ± 91.73 when compared to NT samples (249.75 ± 30.08; 342.95 ± 65.19. The present data indicate that p300 and ADCY2 are involved in a regulation system for GH when high circulating levels of this hormone are found in zebrafishes.A presença de níveis mais elevados do hormônio de crescimento (GH em animais transgênicos poderia levar a várias alterações fisiológicas. Uma linhagem transgênica de paulistinha (Danio rerio para o GH foi comparada com amostras não transgênicas (NT desta espécie, através de uma abordagem de DDRT-PCR, com o objetivo de identificar transcritos candidatos diferencialmente expressos em tecido cerebral que poderiam estar envolvidos na superexpressão de GH. Análises densitométricas de dois produtos de amplificação selecionados, p300 e ADCY2, apontaram uma expressão gênica significativamente menor nas amostras transgênicas de paulistinha (104.02 ± 57.71; 224.10 ± 91.73, quando comparadas com as amostras NT (249.75 ± 30.08; 342.95±65.19. Os presentes dados indicam que p300 e ADCY2 estão envolvidos em um sistema de regulação do GH, quando altos níveis circulantes desse hormônio são encontrados em paulistinha.

  15. Global gene expression in larval zebrafish (Danio rerio) exposed to selective serotonin reuptake inhibitors (fluoxetine and sertraline) reveals unique expression profiles and potential biomarkers of exposure

    Park, June-Woo; Heah, Tze Ping; Gouffon, Julia S.; Henry, Theodore B.; Sayler, Gary S.

    2012-01-01

    Larval zebrafish (Danio rerio) were exposed (96 h) to selective serotonin reuptake inhibitors (SSRIs) fluoxetine and sertraline and changes in transcriptomes analyzed by Affymetrix GeneChip ® Zebrafish Array were evaluated to enhance understanding of biochemical pathways and differences between these SSRIs. The number of genes differentially expressed after fluoxetine exposure was 288 at 25 μg/L and 131 at 250 μg/L; and after sertraline exposure was 33 at 25 μg/L and 52 at 250 μg/L. Same five genes were differentially regulated in both SSRIs indicating shared molecular pathways. Among these, the gene coding for FK506 binding protein 5, annotated to stress response regulation, was highly down-regulated in all treatments (results confirmed by qRT-PCR). Gene ontology analysis indicated at the gene expression level that regulation of stress response and cholinesterase activities were influenced by these SSRIs, and suggested that changes in transcription of these genes could be used as biomarkers of SSRI exposure. - Highlights: ► Exposure of zebrafish to selective serotonin reuptake inhibitors (SSRIs). ► Fluoxetine and sertraline generate different global gene expression profiles. ► Genes linked to stress response and acetylcholine esterase affected by both SSRIs. - Global gene expression profiles in zebrafish exposed to selective serotonin reuptake inhibitors.

  16. Comparative ecotoxicity of potential biofuels to water flea (Daphnia magna), zebrafish (Danio rerio) and Chinese hamster (Cricetulus griseus) V79 cells.

    Heger, Sebastian; Du, Miaomiao; Bauer, Kevin; Schäffer, Andreas; Hollert, Henner

    2018-08-01

    The ecotoxicity of two biofuel candidates (1‑octanol and 2‑butanone) was investigated by an integrative test strategy using three bioassays: the acute immobilisation test with water flea (D. magna), the fish embryo acute toxicity test with zebrafish (Danio rerio) and the in vitro micronucleus assay with Chinese hamster (Cricetulus griseus) V79 cells. The median effective concentration (EC 50 ) values were 14.9±0.66mgL -1 for 1‑octanol, and 2152.1±44.6mgL -1 for 2‑butanone in the D. magna test. Both 1‑octanol and 2‑butanone caused teratogenic and lethal effects on zebrafish embryos, while exposure to 1‑octanol significantly induced these effects at concentrations ≥2.0mgL -1 . These results indicate that 1‑octanol exert much higher ecotoxicity than 2‑butanone to D. magna and zebrafish embryos. Moreover, both 1‑octanol and 2‑butanone did not cause significant genotoxic effects, while their metabolites significantly induced micronuclei in V79 cells. The present study proposed an integrative test approach to evaluate the potential ecotoxicity of biofuels using simple, quick and inexpensive bioassays. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Effects of Short-Term Exposure to Sublethal Concentrations of Silver Nanoparticles on Histopathology and Electron Microscope Ultrastructure of Zebrafish (Danio Rerio Gills

    Borhan Mansouri

    2015-11-01

    Full Text Available Background: The increasing use of nanomaterials and nanoproducts has increased the possibility of contamination of the environment, which may have adverse effects on different organisms. The aim of this study was to evaluate the effects of silver nanoparticles on histopathology and gill ultrastructure of zebrafish (Danio rerio under laboratory conditions. Methods: Zebrafish were exposed to four concentrations of silver nanoparticles (0.0015, 0.00375, 0.0075, and 0.015 mg/l for a period of 4 days. Gill ultrastructure and histopathological changes were studied using scanning electron microscope and haematoxylin - eosin staining. Results: Exposure to silver nanoparticles significantly (P < 0.001 increased the diameter of gill filaments and secondary lamellae, while silver nanoparticles significantly reduced the length of the secondary gills in zebrafish. Moreover, other changes such as vacuolization, dilated and clubbed tips, hyperplasia, edema, fusion, swelling of mucocytes, hypertrophy, and necrosis were observed. The effects of silver nanoparticles in zebrafish gills were dose dependent. Conclusion: Based on the adverse effects of AgNPs on zebrafish gills, silver nanoparticle solutions can be hazardous pollutants for the environment.

  18. Early life exposure to environmental levels of the aromatase inhibitor tributyltin causes masculinisation and irreversible sperm damage in zebrafish (Danio rerio).

    McAllister, Brian G; Kime, David E

    2003-11-19

    To determine whether early life exposure to tributyltin (TBT), an aromatase inhibitor, impaired reproductive function in fish, Danio rerio were exposed to environmentally realistic levels (0.01-100 ng l(-1)) of TBT from 0 to 30, 30 to 60, and 0 to 70 days post-hatch, and the sex ratio and sperm motility of the adults examined 3-5 months after cessation of exposure. Fish exposed for 70 days to 0.1 ng l(-1) of TBT, a concentration presently below the detection limit in water, showed a male biased population which produced a high incidence of sperm lacking flagella. At 1 ng l(-1), the motility of sperm was significantly lower than that of control fish, while at 10 ng l(-1), all sperm lacked flagella and, at 100 ng l(-1), milt volume had increased. The effect of exposure on sex ratio was similar after exposure from 0 to 70 and 0 to 30 days, but even 100 ng l(-1) gave only 65% males after exposure from 30 to 60 days. Effects on sperm motility and morphology and on milt volume were less pronounced after 30 day than 70 day exposure. Our data suggest that screening for aromatase inhibiting activity and assessment of its risks in early life to human and wildlife fertility needs to be urgently addressed, and that the reproductive toxicity of TBT may presently be underestimated.

  19. On the relevance of genotoxicity for fish populations I: effects of a model genotoxicant on zebrafish (Danio rerio) in a complete life-cycle test.

    Diekmann, Markus; Hultsch, Veit; Nagel, Roland

    2004-05-28

    Genotoxicity may be detected in surface waters by means of various genotoxicity assays. In order to enable an ecotoxicological assessment of the consequences of such genotoxic potential for fish populations, a complete life-cycle test with zebrafish (Danio rerio) and the model genotoxicant 4-nitroquinoline-1-oxide (NQO) was conducted. Zebrafish (f1) were continuously exposed to NQO (i.e. 0.1, 0.3, 1.1, 2.9, and 14.6 microg/l, respectively) from fertilised eggs until sexual maturity. In addition to reproduction studies in the f1-generation, f2-fish were exposed to NQO during the first 6 weeks of development. Up to 2.9 microg/l NQO, fish did not display differences in survival and growth (P < 0.05). A NQO concentration of 14.6 microg/l, however, was lethal. Female fish exposed to all NQO concentrations up to 2.9 microg/l displayed a significant reduction in egg production (P < 0.05). A mathematical simulation revealed that exposure to weak concentrations of NQO is leading to an elevated extinction risk. Copyright 2004 Elsevier B.V.

  20. Investigation of the Effects of Perfluorooctanoic Acid (PFOA and Perfluorooctane Sulfonate (PFOS on Apoptosis and Cell Cycle in a Zebrafish (Danio rerio Liver Cell Line

    Yuan Cui

    2015-12-01

    Full Text Available This study aimed to explore the effects of perfluorooctanoic acid (PFOA and perfluorooctane sulfonate (PFOS on apoptosis and cell cycle in a zebrafish (Danio rerio liver cell line (ZFL. Treatment groups included a control group, PFOA-IC50, PFOA-IC80, PFOS-IC50 and PFOS-IC80 groups. IC50 and IC80 concentrations were identified by cellular modeling and MTT assays. mRNA levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were detected by qPCR. Cell apoptosis and cell cycle were detected by flow cytometry and the protein levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were determined by western blotting. Both PFOA and PFOS inhibited the growth of zebrafish liver cells, and the inhibition rate of PFOS was higher than that of PFOA. Bcl-2 expression levels in the four groups were significantly higher than the control group and Bcl-2 increased significantly in the PFOA-IC80 group. However, the expression levels of Bax in the four treatment groups were higher than the control group. The percentage of cell apoptosis increased significantly with the treatment of PFOA and PFOS (p < 0.05. Cell cycle and cell proliferation were blocked in both the PFOA-IC80 and PFOS-IC80 groups, indicating that PFOA-IC80 and PFOS-IC50 enhanced apoptosis in ZFL cells.

  1. Long-term effects of antibiotics, norfloxacin, and sulfamethoxazole, in a partial life-cycle study with zebrafish (Danio rerio): effects on growth, development, and reproduction.

    Yan, Zhenhua; Lu, Guanghua; Ye, Qiuxia; Liu, Jianchao

    2016-09-01

    A partial life-cycle study with zebrafish (Danio rerio) was conducted to evaluate the long-term effects of antibiotics, norfloxacin (NOR) and sulfamethoxazole (SMX). A series of bio-endpoints correlated to the growth, development, and reproduction was assessed. The results showed that the body weight and the condition factor were depressed by SMX at 200 μg/L during the growth period. Meanwhile, the activities of metabolic enzyme (ethoxyresorufin O-deethylase, EROD) and antioxidant enzymes (superoxide dismutase, SOD and catalase, CAT) were stimulated in all cases. The consequences of parental exposure to antibiotics for the next generation were also examined. The egg production of parents were depressed by the 200 μg/L NOR and SMX alone or in combination. Similarly, decreased hatching, survival, and enhanced development abnormality of the next generation also occurred after parental exposure to SMX at the highest concentration. The heartbeat however was not altered in all cases. Furthermore, there was no significant difference in the bio-endpoints between the combined and individual treatment in most cases, with the exception of lower EROD activity and egg production in the co-treatment. The results suggest that long-term exposure to NOR and SMX at environmentally relevant concentrations, individually and in a mixture, may not significantly pose a threat to the growth, development, and reproduction of zebrafish, and an adverse effect may be expected at high concentration.

  2. The effects of dietary Myrtle (Myrtus communis) on skin mucus immune parameters and mRNA levels of growth, antioxidant and immune related genes in zebrafish (Danio rerio).

    Safari, Roghieh; Hoseinifar, Seyed Hossein; Van Doan, Hien; Dadar, Maryam

    2017-07-01

    Myrtle (Myrtus communis L., Myrtaceae) is a significant plant which naturally distributed around the globe. Although numerous studies have demonstrated the benefits of myrtle in different species, studies using the oral route are rare in the literature. In the present study, we evaluated the effect of myrtle intake on the antioxidant, immune, appetite and growth related genes as well as mucosal immune responses in zebrafish (Danio rerio) model. Zebrafish were fed control or myrtle (5, 10 and 20 g kg -1 myrtle) supplemented diets for sixty days. The results showed that, oral administration of Myrtle significantly improved mucosal immune responses (the activity of lysozyme, total Ig and protease). Furthermore, fish fed 20 g kg -1 showed remarkably higher antioxidant (sod and cat) enzymes gene expression compared other treatment. There were significant difference between myrtle fed fish and control group regarding tnf-alpha and lyz expression. Also, evaluation of growth (gh and igf1) related genes revealed remarkable upregulation in 20 g kg -1 myrtle treatment compared other myrtle treatments and control group. Similar results was observed regarding the mRNA levels of appetite related genes (ghrl) in zebrafish fed 20 g kg -1 myrtle. The present results indicated that dietary administration of myrtle improved mucosal immune parameters and altered mRNA levels of selected genes. These results on zebrafish model also highlights the potential use of Myrtle supplements as additive in human diets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Light regimes differentially affect baseline transcript abundance of stress-axis and (neurodevelopment-related genes in zebrafish (Danio rerio, Hamilton 1822 AB and TL larvae

    Ruud van den Bos

    2017-11-01

    Full Text Available Many strains of zebrafish (Danio rerio are readily available. Earlier we observed differences between AB and Tupfel long-fin (TL larvae regarding baseline hypothalamus-pituitary-interrenal (HPI axis activity and (neurodevelopment. Light regimes, i.e. 14 h light:10 h dark and 24 h continuous dark or light, affect hatching rate and larval growth. Here, we assessed baseline transcript abundance of HPI-axis-related genes and (neurodevelopment-related genes of AB and TL larvae (5 days post fertilisation using these light regimes. A principal component analysis revealed that in AB larvae the baseline expression of HPI-axis-related genes was higher the more hours of light, while the expression of (neurodevelopment-related genes was higher under 14 h light:10 h dark than under both continuous light or dark. In TL larvae, a complex pattern emerged regarding baseline expression of HPI-axis-related and (neurodevelopment-related genes. These data extend data of earlier studies by showing that light regimes affect gene-expression in larvae, and more importantly so, strengthen the notion of differences between larvae of the AB and TL strain. The latter finding adds to the growing database of phenotypical differences between zebrafish of the AB and TL strain.

  4. Assessment of cardiotoxicity and effects of malathion on the early development of zebrafish (Danio rerio) using computer vision for heart rate quantification.

    Simoneschi, Daniele; Simoneschi, Francesco; Todd, Nancy E

    2014-06-01

    Malathion, a common organophosphate insecticide, is a proven acetylcholinesterase inhibitor and is the most applied organophosphate insecticide in the United States. The use of zebrafish as a model to study the effects of pesticides on development is an innovative approach yielding relevant implications for determining the potential toxic effects of these pesticides on humans. In this study, a simple noninvasive technique was developed to investigate the cardiotoxicity of malathion on Danio rerio embryos, and to detect and quantify its effect on heart rate. Videos were recorded under a stereomicroscope and examined with our custom-made software (FishBeat) to determine the heart rate of the embryos. The pixel average intensity frequency (PI) of the videos was computed at its maximum probability to indicate the average number of heartbeats per second. Experimental observations successfully demonstrated that this method was able to detect the heart rate of zebrafish embryos as compared with manual stopwatch counting, with no significant difference. Embryos were treated acutely with increasing malathion concentrations (33.3 and 50 μg/mL malathion) at 52, 76, and 96 hpf. Embryos treated with 33.3 μg/mL malathion had significant bradycardia at 52 and 76 hpf, whereas embryos treated with 50 μg/mL malathion presented bradycardia at all hpf. These novel observations confirmed that malathion, acting as an acetylcholinesterase inhibitor, induced heartbeat irregularity in zebrafish embryos.

  5. Cloning, characterization, and heat stress-induced redistribution of a protein homologous to human hsp27 in the zebrafish Danio rerio

    Mao Li; Bryantsev, Anton L.; Chechenova, Maria B.; Shelden, Eric A.

    2005-01-01

    Hsp27 is a small heat shock protein (shsp) regulating stress tolerance and increasingly thought to play roles in tissue homeostasis and differentiation. The zebrafish Danio rerio is an important model for the study of developmental processes, but little is known regarding shsps in this animal. Here, we report the sequence, expression, regulation, and function of a zebrafish protein (zfHsp27) homologous to human Hsp27. zfHsp27 contains three conserved phosphorylatable serines and a cysteine important for regulation of apoptosis, but it lacks much of a C-terminal tail domain and shows low homology in two putative actin interacting domains that are features of mammalian Hsp27. zfHsp27 mRNA is most abundant in adult skeletal muscle and heart and is upregulated during early embryogenesis. zfHsp27 expressed in mammalian fibroblasts was phosphorylated in response to heat stress and anisomycin, and this phosphorylation was prevented by treatment with SB202190, an inhibitor of p38 MAPK. Expression of zfHsp27 and human Hsp27 in mammalian fibroblasts promoted a similar degree of tolerance to heat stress. zfHsp27 fusion proteins entered the nucleus and associated with the cytoskeleton of heat stressed cells in vitro and in zebrafish embryos. These results reveal conservation in regulation and function of mammalian and teleost Hsp27 proteins and define zebrafish as a new model for the study of Hsp27 function

  6. Effects of acute changes in salinity and temperature on routine metabolism and nitrogen excretion in gambusia (Gambusia affinis) and zebrafish (Danio rerio).

    Uliano, E; Cataldi, M; Carella, F; Migliaccio, O; Iaccarino, D; Agnisola, C

    2010-11-01

    Acute stress may affect metabolism and nitrogen excretion as part of the adaptive response that allows animals to face adverse environmental changes. In the present paper the acute effects of different salinities and temperatures on routine metabolism, spontaneous activity and excretion of ammonia and urea were studied in two freshwater fish: gambusia, Gambusia affinis and zebrafish, Danio rerio, acclimated to 27 degrees C. The effects on gill morphology were also evaluated. Five salinities (0 per thousand, 10 per thousand, 20 per thousand, 30 per thousand and 35 per thousand) were tested in gambusia, while four salinities were used in zebrafish (0 per thousand, 10 per thousand, 20 per thousand and 25 per thousand). Each salinity acute stress was tested alone or in combination with an acute temperature reduction to 20 degrees C. In gambusia, both salinity and temperature acute stress strongly stimulated urea excretion. Routine oxygen consumption was barely affected by acute salinity or temperature stress, and was reduced by the combined effects of temperature and high salinity. Gills maintained their structural integrity in all stressing conditions; hyperplasia and hypertrophy of mitochondria-rich cells were observed. In zebrafish, temperature and salinity acute changes, both alone and in combination, scarcely affected any parameter tested. The major effect observed was a reduction of nitrogen excretion at 20 degrees C-25 per thousand; under these extreme conditions a significant structural disruption of gills was observed. These results confirm the high tolerance to acute salinity and temperature stress in gambusia, and demonstrate the involvement of urea excretion modulation in the stress response in this species. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Zebrafish ( Danio rerio) as a model for investigating the safety of GM feed ingredients (soya and maize); performance, stress response and uptake of dietary DNA sequences.

    Sissener, Nini H; Johannessen, Lene E; Hevrøy, Ernst M; Wiik-Nielsen, Christer R; Berdal, Knut G; Nordgreen, Andreas; Hemre, Gro-Ingunn

    2010-01-01

    A 20-d zebrafish (Danio rerio) feeding trial, in which a near doubling of fish weight was achieved, was conducted with GM feed ingredients to evaluate feed intake, growth, stress response and uptake of dietary DNA. A partial aim of the study was to assess zebrafish as a model organism in GM safety assessments. Roundup Ready soya (RRS), YieldGard Bt maize (MON810) and their non-modified, maternal, near-isogenic lines were used in a 2 x 2 factorial design. Soya variety and maize variety were the main factors, both with two levels; non-GM and GM. Compared with fish fed non-GM maize, those fed GM maize exhibited significantly better growth, had lower mRNA transcription levels of superoxide dismutase (SOD)-1 and a tendency (non-significant) towards lower transcription of heat shock protein 70 in liver. Sex of the fish and soya variety had significant interaction effects on total RNA yield from the whole liver and transcription of SOD-1, suggesting that some diet component affecting males and females differently was present in different levels in the GM and the non-GM soya used in the present study. Dietary DNA sequences were detected in all of the organs analysed, but not all of the samples. Soya and maize rubisco (non-transgenic, multicopy genes) were most frequently detected, while MON810 transgenic DNA fragments were detected in some samples and RRS fragments were not detected. In conclusion, zebrafish shows promise as a model for this application.

  8. Bioaccumulation Behavior of Pharmaceuticals and Personal Care Products in Adult Zebrafish (Danio rerio): Influence of Physical-Chemical Properties and Biotransformation.

    Chen, Fangfang; Gong, Zhiyuan; Kelly, Barry C

    2017-10-03

    The factors influencing bioaccumulation of pharmaceuticals and personal care products (PPCPs) in aquatic organisms are not well understood. The present study involved a comprehensive laboratory investigation to assess the bioaccumulation behavior of several PPCPs in adult zebrafish (Danio rerio). The studied PPCPs included several ionogenic organic compounds (IOCs) such as weak acids and weak bases. Experiments involved two exposure groups (high and low) and a control group, with a 6 day aqueous exposure, followed by a 7 day depuration phase under flow-through conditions. Uptake rate constants (k u ) ranged between 0.19 and 8610 L·kg -1 ·d -1 , while depuration rate constants (k d ) ranged between 0.14 and 5.14 d -1 in different fish tissues. Steady-state bioconcentration factor (BCF ss ) values varied widely among the studied PPCPs, ranging from 0.09 to 6,460. In many cases, BCF ss values of individual PPCPs differed substantially among different fish tissues. Positive linear relationships were observed between log BCF ss values and physical-chemical properties such as octanol-water distribution coefficients (log D ow ), membrane-water distribution coefficients (log D mw ), albumin-water distribution coefficients (log D BSAw ), and muscle protein-water distribution coefficients (log D mpw ), indicating the importance of lipid-, phospholipid-, and protein-water partitioning. The results also showed that for many PPCPs, the estimated whole-body metabolism rate constant (k m ) values were comparable to the observed depuration rate (k d ), indicating that metabolism plays a major role in the overall elimination of these compounds in zebrafish. An exception was sertraline, which exhibited a k d value (0.4-0.5 d -1 ) that was much higher than the estimated whole-body k m (0.03 d -1 ). Overall, the results help to better understand the influence of physical-chemical properties and biotransformation on bioaccumulation behavior of these contaminants of concern in aquatic

  9. Oxidative stress markers in fish (Astyanax sp. and Danio rerio) exposed to urban and agricultural effluents in the Brazilian Pampa biome.

    Costa-Silva, D G; Nunes, M E M; Wallau, G L; Martins, I K; Zemolin, A P P; Cruz, L C; Rodrigues, N R; Lopes, A R; Posser, T; Franco, J L

    2015-10-01

    Aquatic ecosystems are under constant risk due to industrial, agricultural, and urban activities, compromising water quality and preservation of aquatic biota. The assessment of toxicological impacts caused by pollutants to aquatic environment using biomarker measurements in fish can provide reliable data to estimate sublethal effects posed by chemicals in contaminated areas. In this study, fish (Astyanax sp. and Danio rerio) exposed to agricultural and urban effluents at the Vacacaí River, Brazil, were tested for potential signs of aquatic contamination. This river comprehends one of the main watercourses of the Brazilian Pampa, a biome with a large biodiversity that has been neglected in terms of environmental and social-economic development. Sites S1 and S2 were chosen by their proximity to crops and wastewater discharge points, while reference site was located upstream of S1 and S2, in an apparently non-degraded area. Fish muscle and brain tissues were processed for determination of acetylcholinesterase as well as oxidative stress-related biomarkers. The results showed signs of environmental contamination, hallmarked by significant changes in cholinesterase activity, expression of metallothionein, antioxidant enzymes, glutathione levels, and activation of antioxidant/cell stress response signaling pathways in fish exposed to contaminated sites when compared to reference. Based on these results, it is evidenced that urban and agricultural activities are posing risk to the environmental quality of water resources at the studied area. It is also demonstrated that cell stress biomarkers may serve as important tools for biomonitoring and development of risk assessment protocols in the Pampa biome.

  10. Bifenthrin causes transcriptomic alterations in mTOR and ryanodine receptor-dependent signaling and delayed hyperactivity in developing zebrafish (Danio rerio).

    Frank, Daniel F; Miller, Galen W; Harvey, Danielle J; Brander, Susanne M; Geist, Juergen; Connon, Richard E; Lein, Pamela J

    2018-04-18

    Over the last few decades, the pyrethroid insecticide bifenthrin has been increasingly employed for pest control in urban and agricultural areas, putting humans and wildlife at increased risk of exposure. Exposures to nanomolar (nM) concentrations of bifenthrin have recently been reported to alter calcium oscillations in rodent neurons. Neuronal calcium oscillations are influenced by ryanodine receptor (RyR) activity, which modulates calcium-dependent signaling cascades, including the mechanistic target of rapamycin (mTOR) signaling pathway. RyR activity and mTOR signaling play critical roles in regulating neurodevelopmental processes. However, whether environmentally relevant levels of bifenthrin alter RyR or mTOR signaling pathways to influence neurodevelopment has not been addressed. Therefore, our main objectives in this study were to examine the transcriptomic responses of genes involved in RyR and mTOR signaling pathways in zebrafish (Danio rerio) exposed to low (ng/L) concentrations of bifenthrin, and to assess the potential functional consequences by measuring locomotor responses to external stimuli. Wildtype zebrafish were exposed for 1, 3 and 5 days to 1, 10 and 50 ng/L bifenthrin, followed by a 14 d recovery period. Bifenthrin elicited significant concentration-dependent transcriptional responses in the majority of genes examined in both signaling cascades, and at all time points examined during the acute exposure period (1, 3, and 5 days post fertilization; dpf), and at the post recovery assessment time point (19 dpf). Changes in locomotor behavior were not evident during the acute exposure period, but were observed at 19 dpf, with main effects (increased locomotor behavior) detected in fish exposed developmentally to bifenthrin at 1 or 10 ng/L, but not 50 ng/L. These findings illustrate significant influences of developmental exposures to low (ng/L) concentrations of bifenthrin on neurodevelopmental processes in zebrafish. Copyright © 2018

  11. Fluoride exposure abates pro-inflammatory response and induces in vivo apoptosis rendering zebrafish (Danio rerio) susceptible to bacterial infections.

    Singh, Rashmi; Khatri, Preeti; Srivastava, Nidhi; Jain, Shruti; Brahmachari, Vani; Mukhopadhyay, Asish; Mazumder, Shibnath

    2017-04-01

    The present study describes the immunotoxic effect of chronic fluoride exposure on adult zebrafish (Danio rerio). Zebrafish were exposed to fluoride (71.12 mg/L; 1/10 LC 50 ) for 30 d and the expression of selected genes studied. We observed significant elevation in the detoxification pathway gene cyp1a suggesting chronic exposure to non-lethal concentration of fluoride is indeed toxic to fish. Fluoride mediated pro-oxidative stress is implicated with the downregulation in superoxide dismutase 1 and 2 (sod1/2) genes. Fluoride affected DNA repair machinery by abrogating the expression of the DNA repair gene rad51 and growth arrest and DNA damage inducible beta a gene gadd45ba. The upregulated expression of casp3a coupled with altered Bcl-2 associated X protein/B-cell lymphoma 2 ratio (baxa/bcl2a) clearly suggested chronic fluoride exposure induced the apoptotic cascade in zebrafish. Fluoride-exposed zebrafish when challenged with non-lethal dose of fish pathogen A. hydrophila revealed gross histopathology in spleen, bacterial persistence and significant mortality. We report that fluoride interferes with system-level output of pro-inflammatory cytokines tumour necrosis factor-α, interleukin-1β and interferon-γ, as a consequence, bacteria replicate efficiently causing significant fish mortality. We conclude, chronic fluoride exposure impairs the redox balance, affects DNA repair machinery with pro-apoptotic implications and suppresses pro-inflammatory cytokines expression abrogating host immunity to bacterial infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The hazard assessment of nanostructured CeO{sub 2}-based mixed oxides on the zebrafish Danio rerio under environmentally relevant UV-A exposure

    Jemec, Anita, E-mail: anita.jemec@bf.uni-lj.si [National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana (Slovenia); University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, SI-1000 Ljubljana (Slovenia); Djinović, Petar; Črnivec, Ilja Gasan Osojnik; Pintar, Albin [National Institute of Chemistry, Laboratory for Environmental Sciences and Engineering, Hajdrihova 19, SI-1001 Ljubljana (Slovenia)

    2015-02-15

    The effect of nanomaterials on biota under realistic environmental conditions is an important question. However, there is still a lack of knowledge on how different illumination conditions alter the toxicity of some photocatalytic nanomaterials. We have investigated how environmentally relevant UV-A exposure (intensity 8.50 ± 0.61 W/m{sup 2}, exposure dose 9.0 J/cm{sup 2}) affected the toxicity of cerium oxide (CeO{sub 2})-based nanostructured materials to the early-life stages of zebrafish Danio rerio. Pure cerium oxide (CeO{sub 2}), copper–cerium (CuO–CeO{sub 2}) (with a nominal 10, 15 and 20 mol.% CuO content), cerium–zirconium (CeO{sub 2}–ZrO{sub 2}) and nickel and cobalt (Ni–Co) deposited over CeO{sub 2}–ZrO{sub 2} were tested. It was found that under both illumination regimes, none of the tested materials affected the normal development or induced mortality of zebrafish early-life stages up to 100 mg/L. Only in the case of CuO–CeO{sub 2}, the growth of larvae was decreased (96 h LOEC values for CuCe10, CuCe15 and CuCe20 were 50, 50 and 10 mg/L, respectively). To conclude, CeO{sub 2}-based nanostructured materials are not severely toxic to zebrafish and environmentally relevant UV-A exposure does not enhance their toxicity. - Highlights: • CeO{sub 2}–ZrO{sub 2} nanomaterials and pure CeO{sub 2} (up to 100 mg/L) were not harmful to zebrafish. • Only CuO modified CeO{sub 2} affected the growth of zebrafish larvae. • UV-A radiation did not enhance the toxicity of tested nanomaterials.

  13. The gonadotropin-inhibitory hormone (Lpxrfa) system's regulation of reproduction in the brain-pituitary axis of the zebrafish (Danio rerio).

    Spicer, Olivia Smith; Zmora, Nilli; Wong, Ten-Tsao; Golan, Matan; Levavi-Sivan, Berta; Gothilf, Yoav; Zohar, Yonathan

    2017-05-01

    Gonadotropin-inhibitory hormone (GNIH) was discovered in quail with the ability to reduce gonadotropin expression/secretion in the pituitary. There have been few studies on GNIH orthologs in teleosts (LPXRFamide (Lpxrfa) peptides), which have provided inconsistent results. Therefore, the goal of this study was to determine the roles and modes of action by which Lpxrfa exerts its functions in the brain-pituitary axis of zebrafish (Danio rerio). We localized Lpxrfa soma to the ventral hypothalamus, with fibers extending throughout the brain and to the pituitary. In the preoptic area, Lpxrfa fibers interact with gonadotropin-releasing hormone 3 (Gnrh3) soma. In pituitary explants, zebrafish peptide Lpxrfa-3 downregulated luteinizing hormone beta subunit and common alpha subunit expression. In addition, Lpxrfa-3 reduced gnrh3 expression in brain slices, offering another pathway for Lpxrfa to exert its effects on reproduction. Receptor activation studies, in a heterologous cell-based system, revealed that all three zebrafish Lpxrfa peptides activate Lpxrf-R2 and Lpxrf-R3 via the PKA/cAMP pathway. Receptor activation studies demonstrated that, in addition to activating Lpxrf receptors, zebrafish Lpxrfa-2 and Lpxrfa-3 antagonize Kisspeptin-2 (Kiss2) activation of Kisspeptin receptor-1a (Kiss1ra). The fact that kiss1ra-expressing neurons in the preoptic area are innervated by Lpxrfa-ir fibers suggests an additional pathway for Lpxrfa action. Therefore, our results suggest that Lpxrfa may act as a reproductive inhibitory neuropeptide in the zebrafish that interacts with Gnrh3 neurons in the brain and with gonadotropes in the pituitary, while also potentially utilizing the Kiss2/Kiss1ra pathway. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    Eide, Marta; Rusten, Marte; Male, Rune; Jensen, Knut Helge Midtbø; Goksøyr, Anders

    2014-01-01

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  15. Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio to Acute and Chronic Temperature Change Using High-Resolution Echocardiography.

    Ling Lee

    Full Text Available The zebrafish (Danio rerio is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1 determine if high resolution echocardiography (HRE in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2 if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR appears to be the critical factor in modifying cardiac output (CO with ambient temperature fluctuation as it increases from 78 ± 5.9 bpm at 18°C to 162 ± 9.7 bpm at 28°C regardless of acclimation state (cold acclimated CA- 18°C; warm acclimated WA- 28°C. Stroke volume (SV is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 ± 0.15 μL at 18°C vs 1.06 ± 0.14 μl at 28°C; WA 1.10 ± 0.13 μL at 18°C vs 1.12 ± 0.12 μl at 28°C. The isovolumetric contraction time (IVCT was significantly shorter in CA fish at 18°C. The CA group showed improved systolic function at 18°C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E velocity and early peak velocity / atrial peak velocity (E/A ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling.

  16. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    Eide, Marta, E-mail: marta.eide@bio.uib.no [Department of Biology, University of Bergen, Bergen (Norway); Rusten, Marte; Male, Rune [Department of Molecular Biology, University of Bergen, Bergen (Norway); Jensen, Knut Helge Midtbø; Goksøyr, Anders [Department of Biology, University of Bergen, Bergen (Norway)

    2014-02-15

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  17. Effects of {sup 12}C{sup 6+} ion radiation and ferulic acid on the zebrafish (Danio rerio) embryonic oxidative stress response and gene expression

    Si, Jing [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Zhang, Hong, E-mail: zhangh@impcas.ac.cn [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang, Zhenhua; Wu, Zhenhua [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Lu, Jiang [Key Laboratory of Xinjiang Phytomedicine Resources, College of Pharmacy, Shihezi University, Shihezi 832002 (China); Di, Cuixia; Zhou, Xin [Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Medicine of Gansu Province, Lanzhou 730000 (China); Wang, Xiaowei [Key Laboratory of Xinjiang Phytomedicine Resources, College of Pharmacy, Shihezi University, Shihezi 832002 (China)

    2013-05-15

    Highlights: • Carbon ion radiation increased the oxidative stress in zebrafish embryos. • Carbon ion radiation induced transcriptional level effects. • The transcriptional level displayed more sensitivity to low dose radiation than the antioxidant enzyme activities. • FA induced radioprotective effects by the inhibition of oxidative stress. - Abstract: The effects of carbon ion irradiation and ferulic acid (FA) on the induction of oxidative stress and alteration of gene expression were studied in zebrafish (Danio rerio) embryos. Zebrafish embryos at 8 hpf were divided into seven groups: the control group; the 1 Gy, 3 Gy and 7 Gy irradiation groups; and three FA-pre-treated irradiation groups. In the irradiated groups, a significant increase in the teratogenesis of the zebrafish embryos and oxidative stress was accompanied by increased malondialdehyde (MDA) content, decreased glutathione (GSH) content and alterations in antioxidant enzyme activities (such as catalase [CAT] and superoxide dismutase [SOD]). Moreover, the mRNA levels for Cu/Zn–sod, Mn–sod, cat and gpx, the genes encoding these antioxidant proteins, were altered significantly. However, the mRNA expression patterns were not in accordance with those of the antioxidant enzymes and were more sensitive under low-dose irradiation. In addition, we detected the mRNA expression of ucp-2 and bcl-2, which are located at the mitochondrial inner membrane and related to reactive oxidative species (ROS) production. In the irradiated groups, the mRNA level of ucp-2 was significantly increased, whereas the mRNA level of bcl-2 was significantly decreased. Supplementation with FA, an antioxidant, was better able to reduce the irradiation-induced oxidative damage marked by changes in mortality, morphology, antioxidant enzyme activities and the MDA and GSH content, as well as in the mRNA expression levels. Overall, this study provided helpful information about the transcriptional effects of irradiation to better

  18. Structural models of zebrafish (Danio rerio NOD1 and NOD2 NACHT domains suggest differential ATP binding orientations: insights from computational modeling, docking and molecular dynamics simulations.

    Jitendra Maharana

    Full Text Available Nucleotide-binding oligomerization domain-containing protein 1 (NOD1 and NOD2 are cytosolic pattern recognition receptors playing pivotal roles in innate immune signaling. NOD1 and NOD2 recognize bacterial peptidoglycan derivatives iE-DAP and MDP, respectively and undergoes conformational alternation and ATP-dependent self-oligomerization of NACHT domain followed by downstream signaling. Lack of structural adequacy of NACHT domain confines our understanding about the NOD-mediated signaling mechanism. Here, we predicted the structure of NACHT domain of both NOD1 and NOD2 from model organism zebrafish (Danio rerio using computational methods. Our study highlighted the differential ATP binding modes in NOD1 and NOD2. In NOD1, γ-phosphate of ATP faced toward the central nucleotide binding cavity like NLRC4, whereas in NOD2 the cavity was occupied by adenine moiety. The conserved 'Lysine' at Walker A formed hydrogen bonds (H-bonds and Aspartic acid (Walker B formed electrostatic interaction with ATP. At Sensor 1, Arg328 of NOD1 exhibited an H-bond with ATP, whereas corresponding Arg404 of NOD2 did not. 'Proline' of GxP motif (Pro386 of NOD1 and Pro464 of NOD2 interacted with adenine moiety and His511 at Sensor 2 of NOD1 interacted with γ-phosphate group of ATP. In contrast, His579 of NOD2 interacted with the adenine moiety having a relatively inverted orientation. Our findings are well supplemented with the molecular interaction of ATP with NLRC4, and consistent with mutagenesis data reported for human, which indicates evolutionary shared NOD signaling mechanism. Together, this study provides novel insights into ATP binding mechanism, and highlights the differential ATP binding modes in zebrafish NOD1 and NOD2.

  19. Characterization of Danio rerio Mn2+-dependent ADP-ribose/CDP-alcohol diphosphatase, the structural prototype of the ADPRibase-Mn-like protein family.

    Joaquim Rui Rodrigues

    Full Text Available The ADPRibase-Mn-like protein family, that belongs to the metallo-dependent phosphatase superfamily, has different functional and structural prototypes. The functional one is the Mn(2+-dependent ADP-ribose/CDP-alcohol diphosphatase from Rattus norvegicus, which is essentially inactive with Mg(2+ and active with low micromolar Mn(2+ in the hydrolysis of the phosphoanhydride linkages of ADP-ribose, CDP-alcohols and cyclic ADP-ribose (cADPR in order of decreasing efficiency. The structural prototype of the family is a Danio rerio protein with a known crystallographic structure but functionally uncharacterized. To estimate the structure-function correlation with the same protein, the activities of zebrafish ADPRibase-Mn were studied. Differences between zebrafish and rat enzymes are highlighted. The former showed a complex activity dependence on Mn(2+, significant (≈25% Mg(2+-dependent activity, but was almost inactive on cADPR (150-fold less efficient than the rat counterpart. The low cADPR hydrolase activity agreed with the zebrafish genome lacking genes coding for proteins with significant homology with cADPR-forming enzymes. Substrate-docking to zebrafish wild-type protein, and characterization of the ADPRibase-Mn H97A mutant pointed to a role of His-97 in catalysis by orientation, and to a bidentate water bridging the dinuclear metal center as the potential nucleophile. Finally, three structural elements that delimit the active site entrance in the zebrafish protein were identified as unique to the ADPRibase-Mn-like family within the metallo-dependent phosphatase superfamily.

  20. Field emission scanning electron microscopy and transmission electron microscopy studies of the chorion, plasma membrane and syncytial layers of the gastrula-stage embryo of the zebrafish Brachydanio rerio : a consideration of the structural and functional relationships with respect to cryoprotectant penetration

    Rawson, DM; Zhang, T; Kalicharan, D; Jongebloed, WL

    The structure of the chorion and plasma membranes of gastrula-stage zebrafish Brachydanio rerio embryos were studied using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). These studies confirm the outer chorion membrane complex to be 1.5-2.5 mu m in

  1. Molecular networks related to the immune system and mitochondria are targets for the pesticide dieldrin in the zebrafish (Danio rerio) central nervous system.

    Cowie, Andrew M; Sarty, Kathleena I; Mercer, Angella; Koh, Jin; Kidd, Karen A; Martyniuk, Christopher J

    2017-03-22

    The objectives of this study were to determine the behavioral and molecular responses in the adult zebrafish (Danio rerio) central nervous system (CNS) following a dietary exposure to the pesticide dieldrin. Zebrafish were fed pellets spiked with 0.03, 0.15, or 1.8μg/g dieldrin for 21days. Behavioral analysis revealed no difference in exploratory behaviors or those related to anxiety. Transcriptional networks for T-cell aggregation and selection were decreased in expression suggesting an immunosuppressive effect of dieldrin, consistent with other studies investigating organochlorine pesticides. Processes related to oxidative phosphorylation were also differentially affected by dieldrin. Quantitative proteomics (iTRAQ) using a hybrid quadrupole-Orbitrap identified 226 proteins that were different following one or more doses. These proteins included ATP synthase subunits (mitochondrial) and hypoxia up-regulated protein 1 which were decreased and NADH dehydrogenases (mitochondrial) and signal recognition particle 9 which were up-regulated. Thus, proteins affected were functionally associated with the mitochondria and a protein network analysis implicated Parkinson's disease (PD) and Huntington's disease as diseases associated with altered proteins. Molecular networks related to mitochondrial dysfunction and T-cell regulation are hypothesized to underlie the association between dieldrin and PD. These data contribute to a comprehensive transcriptomic and proteomic biomarker framework for pesticide exposures and neurodegenerative diseases. Dieldrin is a persistent organochlorine pesticide that has been associated with human neurodegenerative disease such as Parkinson's disease. Dieldrin is ranked 18th on the 2015 U.S. Agency for Toxic Substances and Disease Registry and continues to be a pesticide of concern for human health. Transcriptomics and quantitative proteomics (ITRAQ) were employed to characterize the molecular networks in the central nervous system that are

  2. Screening on the differentially expressed miRNAs in zebrafish (Danio rerio) exposed to trace β-diketone antibiotics and their related functions

    Li, Jieyi; Liu, Jinfeng; Zhang, Yuhuan; Wang, Xuedong; Li, Weijun; Zhang, Hongqin; Wang, Huili

    2016-01-01

    Highlights: • DKAs possessed toxic effect transfer relation across larval and adult zebrafish. • 215 mature miRNAs were differentially expressed in three comparison groups. • A regulatory network for 4 positive miRNA genes (miR-10, −96, −92, −184) was plotted. • Expression of miR-184, −96, −10 and −92 was proved with miRNA-seq, qRT-PCR and ISH. • DKA exposure induced severe histopathological changes in zebrafish tissues. - Abstract: The toxicity of β-diketone antibiotics (DKAs) to larval and adult zebrafish (Danio rerio) was investigated by miRNA sequencing and bioinformatics analyses. In control and DKA-exposed groups, 215 differentially expressed miRNAs were screened, and 4076 differential target genes were predicted. Among 51 co-differentially expressed genes, 45 were annotated in KOG functional classification, and 34 in KEGG pathway analysis. The homology analysis of 20 miRNAs with human hsa-miRNAs demonstrated 17 high homologous sequences. The expression levels of 12 miRNAs by qRT-PCR were consistent with those by sRNA-seq. A regulatory network for 4 positive miRNA genes (dre-miR-10, −96, −92 and −184) was plotted, and the high-degree of connectivity between miRNA-gene pairs suggests that these miRNAs play critical roles during zebrafish development. The consistent expression of dre-miR-184 and dre-miR-96 was proved in 120-hpf zebrafish brain, gill, otoliths and lateral line neuromast by qRT-PCR, miRNA-seq, W-ISH and ISH. DKA-exposure led to vacuolation of interstitial cells, reduced number of neurons, glial cell proliferation and formation of glial scar, and the obvious abnormality of cell structure might result from abnormal expression of differentially expressed miRNAs. In general, chronic DKA-exposure resulted in comprehensively toxic effects on larval and adult zebrafish tissues, especially for nervous system.

  3. Differential modulation of expression of nuclear receptor mediated genes by tris(2-butoxyethyl) phosphate (TBOEP) on early life stages of zebrafish (Danio rerio)

    Ma, Zhiyuan, E-mail: zhiyuan_nju@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China); Yu, Yijun, E-mail: yjun.yu@gmail.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China); Tang, Song [School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5B3 (Canada); Liu, Hongling, E-mail: hlliu@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China); Su, Guanyong; Xie, Yuwei [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China); Giesy, John P. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China); Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B3 (Canada); Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Hecker, Markus [School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5B3 (Canada); Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3 (Canada); Yu, Hongxia [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023 (China)

    2015-12-15

    Highlights: • Effects of TBOEP on expression of genes of several nuclear hormone receptors and their relationship with adverse effect pathways in zebrafish. • TBOEP was neither an agonist nor antagonist of AR or AhR as determined by use of in vitro mammalian cell-based receptor transactivation assays. • Modulation of ER- and MR-dependent pathways allowed for development of feasible receptor-mediated, critical mechanisms of toxic action. - Abstract: As one substitute for phased-out brominated flame retardants (BFRs), tris(2-butoxyethyl) phosphate (TBOEP) is frequently detected in aquatic organisms. However, knowledge about endocrine disrupting mechanisms associated with nuclear receptors caused by TBOEP remained restricted to results from in vitro studies with mammalian cells. In the study, results of which are presented here, embryos/larvae of zebrafish (Danio rerio) were exposed to 0.02, 0.1 or 0.5 μM TBOEP to investigate expression of genes under control of several nuclear hormone receptors (estrogen receptors (ERs), androgen receptor (AR), thyroid hormone receptor alpha (TRα), mineralocorticoid receptor (MR), glucocorticoid receptor (GR), aryl hydrocarbon (AhR), peroxisome proliferator-activated receptor alpha (PPARα), and pregnane × receptor (P × R)) pathways at 120 hpf. Exposure to 0.5 μM TBOEP significantly (p < 0.05, one-way analysis of variance) up-regulated expression of estrogen receptors (ERs, er1, er2a, and er2b) genes and ER-associated genes (vtg4, vtg5, pgr, ncor, and ncoa3), indicating TBOEP modulates the ER pathway. In contrast, expression of most genes (mr, 11βhsd, ube2i,and adrb2b) associated with the mineralocorticoid receptor (MR) pathway were significantly down-regulated. Furthermore, in vitro mammalian cell-based (MDA-kb2 and H4IIE-luc) receptor transactivation assays, were also conducted to investigate possible agonistic or antagonistic effects on AR- and AhR-mediated pathways. In mammalian cells, none of these pathways were

  4. Screening on the differentially expressed miRNAs in zebrafish (Danio rerio) exposed to trace β-diketone antibiotics and their related functions

    Li, Jieyi; Liu, Jinfeng; Zhang, Yuhuan [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China); Wang, Xuedong [Key Laboratory of Watershed Sciences and Health of Zhejiang Province, Wenzhou Medical University, Wenzhou 325035 (China); Li, Weijun [Puyang People’s Hospital of Henan Province, Puyang 457000 (China); Zhang, Hongqin [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China); Wang, Huili, E-mail: wxdong@wzmc.edu.cn [College of Life Sciences, Wenzhou Medical University, Wenzhou 325035 (China)

    2016-09-15

    Highlights: • DKAs possessed toxic effect transfer relation across larval and adult zebrafish. • 215 mature miRNAs were differentially expressed in three comparison groups. • A regulatory network for 4 positive miRNA genes (miR-10, −96, −92, −184) was plotted. • Expression of miR-184, −96, −10 and −92 was proved with miRNA-seq, qRT-PCR and ISH. • DKA exposure induced severe histopathological changes in zebrafish tissues. - Abstract: The toxicity of β-diketone antibiotics (DKAs) to larval and adult zebrafish (Danio rerio) was investigated by miRNA sequencing and bioinformatics analyses. In control and DKA-exposed groups, 215 differentially expressed miRNAs were screened, and 4076 differential target genes were predicted. Among 51 co-differentially expressed genes, 45 were annotated in KOG functional classification, and 34 in KEGG pathway analysis. The homology analysis of 20 miRNAs with human hsa-miRNAs demonstrated 17 high homologous sequences. The expression levels of 12 miRNAs by qRT-PCR were consistent with those by sRNA-seq. A regulatory network for 4 positive miRNA genes (dre-miR-10, −96, −92 and −184) was plotted, and the high-degree of connectivity between miRNA-gene pairs suggests that these miRNAs play critical roles during zebrafish development. The consistent expression of dre-miR-184 and dre-miR-96 was proved in 120-hpf zebrafish brain, gill, otoliths and lateral line neuromast by qRT-PCR, miRNA-seq, W-ISH and ISH. DKA-exposure led to vacuolation of interstitial cells, reduced number of neurons, glial cell proliferation and formation of glial scar, and the obvious abnormality of cell structure might result from abnormal expression of differentially expressed miRNAs. In general, chronic DKA-exposure resulted in comprehensively toxic effects on larval and adult zebrafish tissues, especially for nervous system.

  5. Functional characterization of a full length pregnane X receptor, expression in vivo, and identification of PXR alleles, in Zebrafish (Danio rerio)

    Bainy, Afonso C.D. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Departamento de Bioquímica, CCB, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900 (Brazil); Kubota, Akira; Goldstone, Jared V. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Lille-Langøy, Roger [Department of Biology, University of Bergen, N-5020 Bergen (Norway); Karchner, Sibel I. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Celander, Malin C. [Department of Biological and Environmental Sciences, University of Gothenburg, SE 405 30 Göteborg (Sweden); Hahn, Mark E. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Goksøyr, Anders [Department of Biology, University of Bergen, N-5020 Bergen (Norway); Stegeman, John J., E-mail: jstegeman@whoi.edu [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2013-10-15

    Highlights: •Full-length pxr has been cloned from zebrafish. •Alleles of pxr were identified in zebrafish. •Full length Pxr was activated less strongly than ligand binding domain in cell-based reporter assays. •High levels of pxr expression were found in eye and brain as well as in liver. •TCPOBOP and PB did not significantly alter expression of pxr in liver. -- Abstract: The pregnane X receptor (PXR) (nuclear receptor NR1I2) is a ligand activated transcription factor, mediating responses to diverse xenobiotic and endogenous chemicals. The properties of PXR in fish are not fully understood. Here we report on cloning and characterization of full-length PXR of zebrafish, Danio rerio, and pxr expression in vivo. Initial efforts gave a cDNA encoding a 430 amino acid protein identified as zebrafish pxr by phylogenetic and synteny analysis. The sequence of the cloned Pxr DNA binding domain (DBD) was highly conserved, with 74% identity to human PXR-DBD, while the ligand-binding domain (LBD) of the cloned sequence was only 44% identical to human PXR-LBD. Sequence variation among clones in the initial effort prompted sequencing of multiple clones from a single fish. There were two prominent variants, one sequence with S183, Y218 and H383 and the other with I183, C218 and N383, which we designate as alleles pxr*1 (nr1i2*1) and pxr*2 (nr1i2*2), respectively. In COS-7 cells co-transfected with a PXR-responsive reporter gene, the full-length Pxr*1 (the more common variant) was activated by known PXR agonists clotrimazole and pregnenolone 16α-carbonitrile but to a lesser extent than the full-length human PXR. Activation of full-length Pxr*1 was only 10% of that with the Pxr*1 LBD. Quantitative real time PCR analysis showed prominent expression of pxr in liver and eye, as well as brain and intestine of adult zebrafish. The pxr was expressed in heart and kidney at levels similar to that in intestine. The expression of pxr in liver was weakly induced by ligands for

  6. The transcription factor, Nuclear factor, erythroid 2 (Nfe2), is a regulator of the oxidative stress response during Danio rerio development

    Williams, Larissa M., E-mail: lwillia2@bates.edu [Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240 (United States); The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA (United States); Lago, Briony A., E-mail: lagoba@mcmaster.ca [M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1 (Canada); McArthur, Andrew G., E-mail: mcarthua@mcmaster.ca [M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1 (Canada); Raphenya, Amogelang R., E-mail: raphenar@mcmaster.ca [M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4K1 (Canada); Pray, Nicholas, E-mail: pray.nicholas@gmail.com [Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240 (United States); Saleem, Nabil, E-mail: nabilsaleem@gmail.com [Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240 (United States); The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA (United States); Salas, Sophia, E-mail: sophia.salas2@gmail.com [Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240 (United States); The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA (United States); Paulson, Katherine, E-mail: krpaulson@gmail.com [Biology Department, Bates College, 44 Campus Avenue, Lewiston, ME 04240 (United States); The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA (United States); Mangar, Roshni S., E-mail: rmangar@coa.edu [The MDI Biological Laboratory, 159 Old Bar Harbor Road, Bar Harbor, ME 04609 USA (United States); College of the Atlantic, 105 Eden Street, Bar Harbor, ME 04609 (United States); and others

    2016-11-15

    Highlights: • Nfe2 is involved in erythropoiesis in zebrafish. • Nfe2 is a novel regulator of pro-oxidant induced oxidative stress. • Embryos mount a molecularly unique oxidative stress response compared to larvae. • Nfe2 regulates a wide-variety of genes beyond erythropoiesis. - Abstract: Development is a complex and well-defined process characterized by rapid cell proliferation and apoptosis. At this stage in life, a developmentally young organism is more sensitive to toxicants as compared to an adult. In response to pro-oxidant exposure, members of the Cap’n’Collar (CNC) basic leucine zipper (b-ZIP) transcription factor family (including Nfe2 and Nfe2-related factors, Nrfs) activate the expression of genes whose protein products contribute to reduced toxicity. Here, we studied the role of the CNC protein, Nfe2, in the developmental response to pro-oxidant exposure in the zebrafish (Danio rerio). Following acute waterborne exposures to diquat or tert-buytlhydroperoxide (tBOOH) at one of three developmental stages, wildtype (WT) and nfe2 knockout (KO) embryos and larvae were morphologically scored and their transcriptomes sequenced. Early in development, KO animals suffered from hypochromia that was made more severe through exposure to pro-oxidants; this phenotype in the KO may be linked to decreased expression of alas2, a gene involved in heme synthesis. WT and KO eleutheroembryos and larvae were phenotypically equally affected by exposure to pro-oxidants, where tBOOH caused more pronounced phenotypes as compared to diquat. Comparing diquat and tBOOH exposed embryos relative to the WT untreated control, a greater number of genes were up-regulated in the tBOOH condition as compared to diquat (tBOOH: 304 vs diquat: 148), including those commonly found to be differentially regulated in the vertebrate oxidative stress response (OSR) (e.g. hsp70.2, txn1, and gsr). When comparing WT and KO across all treatments and times, there were 1170 genes that were

  7. Metabolic programming of zebra fish Danio rerio uncovered. Physiological performance as explained by dynamic energy budget theory and life-cycle consequence of uranium induced perturbations

    Starrlight, A.

    2012-01-01

    The aim of this dissertation is to characterize the toxicity of uranium on the metabolism of zebra fish, nio rerio. The first three chapters of this manuscript are dedicated to characterizing the blank metabolism of zebra fish. I used the Dynamic Energy Budget (deb) theory for this characterisation; it is presently the only theory that covers the full life cycle of the organism and quantifies feeding, assimilation, growth, reproduction, maturation, maintenance and ageing. Any metabolic effect of uranium should appear as effects on one or more of these fundamental processes. Since the life span of zebra fish is some four and a half years, and larger individuals respond slower to chemical stress, the focus was on the early life stages. Considerable breakthroughs in the quantification of zebra fish development, growth and reproduction have been made. It turned out the zebra fish accelerates its metabolism after birth till metamorphosis, when acceleration ceases. This process is seen in some, but not all, species of fish. Another striking conclusion was that somatic maintenance was much higher than is typical for fish. We don't yet have an explanation for this funding. Further it turned out that the details of reproduction matter: allocation to reproduction (in adults) accumulates in a reproduction buffer and this buffer is used to prepare batches of eggs. We needed to detail this preparation process to understand how zebra fish can eliminate uranium via eggs. Deb theory specifies that a particular developmental stage (birth, metamorphosis, puberty) is reached at specified levels of maturity. For different temperatures and food levels, that can occur at different ages and body sizes. We extended this idea to include all the described morphologically defined developmental stages of the zebra fish in the literature; the observed variations in ages and body sizes can now be explained by deb theory. To test if deb theory can also explain perturbations of maturation, we

  8. A Short History of the Hatching Enzyme Studies in Medaka(Development of Medaka Biology in Japan-Part II)

    Yamagami, Kenjiro

    1997-01-01

    The studies on the hatching enzyme of the medaka, Oryzias latipes, have a history of about 50 years, which is only a half of whole history of the studies on the hatching enzyme in animals since the first conjecture of it in a lung fish in 1900. Medaka, however, has served as the material most intensively studied for the enzyme, and the studies have given invaluable information to establish some significant concepts in the field of developmental and cell biology as well as the hatching biology...

  9. Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar)

    Berntssen, M.H.G., E-mail: marc.berntssen@nifes.no [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway); Lundebye, A.-K.; Hop-Johannessen, L.; Lock, E.-J. [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway)

    2012-05-15

    Graphical abstract: - Abstract: The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB N-Ary-Summation 50 + 62 and/or CHB N-Ary-Summation 40 + 41 + 44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40 and 41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as log K{sub ow}). An exception was CHB-44 which had a higher BMF than could be expected from its specific log K{sub ow}, reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

  10. Primera identificación molecular del transgen de la proteína fluorescente roja (RFP en peces Cebra (Danio rerio transgénicos ornamentales introducidos en el Perú

    Carlos Scotto

    2013-01-01

    Full Text Available En el presente trabajo se identificó por primera vez peces Cebra transgénicos (Danio rerio fluorescentes de color rojo, naranja y rosado introducidos al territorio peruano de acuarios locales utilizando la técnica de PCR para amplificar el transgen RFP perteneciente a la anémona marina Discosoma spp. Se encontró una expresión génica diferencial del transgen de la proteína fluorescente roja (RFP que determinaría una gradiente de bioluminiscencia para cada color entre los peces OVM analizados. Se realizó un análisis de secuencias de las dos variantes de la RFP junto con las seis variantes de la GFP de proteínas fluorescentes existentes en el Genbank que podrían ayudar a identificar rápidamente si son nuevos genes o si son nuevas variantes de éstas proteínas fluorescentes y que podrían ser utilizadas en otros OVMs hidrobiológicos a futuro. De este modo, desarrollar y optimizar las medidas de bioseguridad mediante su oportuna detección a nivel genético molecular.

  11. Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar)

    Berntssen, M.H.G.; Lundebye, A.-K.; Hop-Johannessen, L.; Lock, E.-J.

    2012-01-01

    Graphical abstract: - Abstract: The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB ∑50 + 62 and/or CHB ∑40 + 41 + 44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40 and 41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as log K ow ). An exception was CHB-44 which had a higher BMF than could be expected from its specific log K ow , reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

  12. Lipidomics and H218O labeling techniques reveal increased remodeling of DHA-containing membrane phospholipids associated with abnormal locomotor responses in α-tocopherol deficient zebrafish (danio rerio embryos

    Melissa Q. McDougall

    2016-08-01

    Full Text Available We hypothesized that vitamin E (α-tocopherol is required by the developing embryonic brain to prevent depletion of highly polyunsaturated fatty acids, especially docosahexaenoic acid (DHA, 22:6, the loss of which we predicted would underlie abnormal morphological and behavioral outcomes. Therefore, we fed adult 5D zebrafish (Danio rerio defined diets without (E− or with added α-tocopherol (E+, 500 mg RRR-α-tocopheryl acetate/kg diet for a minimum of 80 days, and then spawned them to obtain E− and E+ embryos. The E− compared with E+ embryos were 82% less responsive (p<0.01 to a light/dark stimulus at 96 h post-fertilization (hpf, demonstrating impaired locomotor behavior, even in the absence of gross morphological defects. Evaluation of phospholipid (PL and lysophospholipid (lyso-PL composition using untargeted lipidomics in E− compared with E+ embryos at 24, 48, 72, and 120 hpf showed that four PLs and three lyso-PLs containing docosahexaenoic acid (DHA, including lysophosphatidylcholine (LPC 22:6, required for transport of DHA into the brain, p<0.001, were at lower concentrations in E− at all time-points. Additionally, H218O labeling experiments revealed enhanced turnover of LPC 22:6 (p<0.001 and three other DHA-containing PLs in the E− compared with the E+ embryos, suggesting that increased membrane remodeling is a result of PL depletion. Together, these data indicate that α-tocopherol deficiency in the zebrafish embryo causes the specific depletion and increased turnover of DHA-containing PL and lyso-PLs, which may compromise DHA delivery to the brain and thereby contribute to the functional impairments observed in E− embryos.

  13. Japanese medaka: a non-mammalian vertebrate model for studying sex and age-related bone metabolism in vivo.

    Admane H Shanthanagouda

    Full Text Available BACKGROUND: In human, a reduction in estrogen has been proposed as one of the key contributing factors for postmenopausal osteoporosis. Rodents are conventional models for studying postmenopausal osteoporosis, but the major limitation is that ovariectomy is needed to mimic the estrogen decline after menopause. Interestingly, in medaka fish (Oryzias latipes, we observed a natural drop in plasma estrogen profile in females during aging and abnormal spinal curvature was apparent in old fish, which are similar to postmenopausal women. It is hypothesized that estrogen associated disorders in bone metabolism might be predicted and prevented by estrogen supplement in aging O. latipes, which could be corresponding to postmenopausal osteoporosis in women. PRINCIPAL FINDINGS: In O. latipes, plasma estrogen was peaked at 8 months old and significantly declined after 10, 11 and 22 months in females. Spinal bone mineral density (BMD and micro-architecture by microCT measurement progressively decreased and deteriorated from 8 to 10, 12 and 14 months old, which was more apparent in females than the male counterparts. After 10 months old, O. latipes were supplemented with 17α-ethinylestradiol (EE2, a potent estrogen mimic at 6 and 60 ng/mg fish weight/day for 4 weeks, both reduction in spinal BMD and deterioration in bone micro-architecture were significantly prevented. The estrogenic effect of EE2 in O. latipes was confirmed by significant up-regulation of four key estrogen responsive genes in the liver. In general, bone histomorphometric analyses indicated significantly lowered osteoblasts and osteoclasts numbers and surfaces on vertebrae of EE2-fed medaka. SIGNIFICANCE: We demonstrate osteoporosis development associated with natural drop in estrogen level during aging in female medaka, which could be attenuated by estrogen treatment. This small size fish is a unique alternative non-mammalian vertebrate model for studying estrogen-related molecular

  14. FY 1982 report on the results of the verification test on the methanol conversion for oil-fired power plant. Part 2. Verification test on the environmental safety; 1982 nendo sekiyu karyoku hatsudensho metanoru tenkan tou jissho shiken seika hokokusho. Kankyo anzensei jissho shiken (Sono 2)

    NONE

    1983-03-01

    For the purpose of contributing to the promotion of methanol introduction and establishment of conversion technology, testing research on environmental safety of methanol was conducted, and the FY 1982 results were reported. In this fiscal year, construction was completed of testing facilities for breeding monkey/aquatic animal in the methanol environment, and test was started. In the test on the rapid exposure of macaca to high concentration (10,000ppm), effects were recognized on the blood physiochemistry, urine analysis, cardiac function, cerebral basal nuclei and cinerea part, as a result of various inspections/analyses made after 7-day exposure. Further, for the macaca exposed to a concentration of 3,000ppm, no remarkable changes were observed in urine analysis, pH value, etc. As to the effect of toxicity of methanol on oryzias latipes, toxicity is considerably lower than that of other chemicals. At about 3% concentration, half the number of oryzias latipes was fatal in 96 hours. Further, when diatom is exposed to methanol of concentration of 100ppm or more at the time of starting culture, the diatom continues to be hindered by methanol even after methanol fades away. At the same time, methanol also seems to have effects on the shape and metabolism of diatom. (NEDO)

  15. Cadmium(Cd)-induced oxidative stress down-regulates the gene expression of DNA mismatch recognition proteins MutS homolog 2 (MSH2) and MSH6 in zebrafish (Danio rerio) embryos

    Hsu, Todd, E-mail: toddhsu@mail.ntou.edu.tw [Institute of Bioscience and Biotechnology and Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan (China); Huang, Kuan-Ming; Tsai, Huei-Ting; Sung, Shih-Tsung; Ho, Tsung-Nan [Institute of Bioscience and Biotechnology and Center of Excellence for Marine Bioenvironment and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan (China)

    2013-01-15

    DNA mismatch repair (MMR) of simple base mismatches and small insertion-deletion loops in eukaryotes is initiated by the binding of the MutS homolog 2 (MSH2)-MSH6 heterodimer to mismatched DNA. Cadmium (Cd) is a genotoxic heavy metal that has been recognized as a human carcinogen. Oxidant stress and inhibition of DNA repair have been proposed as major factors underlying Cd genotoxicity. Our previous studies indicated the ability of Cd to disturb the gene expression of MSH6 in zebrafish (Danio rerio) embryos. This study was undertaken to explore if Cd-induced oxidative stress down-regulated MSH gene activities. Following the exposure of zebrafish embryos at 1 h post fertilization (hpf) to sublethal concentrations of Cd at 3-5 {mu}M for 4 or 9 h, a parallel down-regulation of MSH2, MSH6 and Cu/Zn superoxide dismutase (Cu/Zn-SOD) gene expression was detected by real-time RT-PCR and the expression levels were 40-50% of control after a 9-h exposure. Cd exposure also induced oxidative stress, yet no inhibition of catalase gene activity was observed. Whole mount in situ hybridization revealed a wide distribution of msh6 mRNA in the head regions of 10 hpf embryos and pretreatment of embryos with antioxidants butylhydroxytoluene (BHT), D-mannitol or N-acetylcysteine (NAC) at 1-10 {mu}M restored Cd-suppressed msh6 expression. QPCR confirmed the protective effects of antioxidants on Cd-suppressed msh2/msh6 mRNA production. Down-regulated MSH gene activities reaching about 50% of control were also induced in embryos exposed to paraquat, a reactive oxygen species (ROS)-generating herbicide, or hydrogen peroxide at 200 {mu}M. Hence, Cd at sublethal levels down-regulates msh2/msh6 expression primarily via ROS as signaling molecules. The transcriptional activation of human msh6 is known to be fully dependent on the specificity factor 1 (Sp1). Cd failed to inhibit the DNA binding activity of zebrafish Sp1 unless at lethal concentrations based on band shift assay, therefore

  16. Effects of antiandrogenic progestins, chlormadinone and cyproterone acetate, and the estrogen 17α-ethinylestradiol (EE2), and their mixtures: Transactivation with human and rainbowfish hormone receptors and transcriptional effects in zebrafish (Danio rerio) eleuthero-embryos

    Siegenthaler, Patricia Franziska [University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Bain, Peter [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water Flagship, PMB2, Glen Osmond, 5064 South Australia (Australia); Riva, Francesco [IRCCS – Istituto di Ricerche Farmacologiche “Mario Negri”, Environmental Biomarkers Unit, Department of Environmental Health Sciences, Via La Masa 19, I-20156 Milan (Italy); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETH Zürich), Institute of Biogeochemistry and Pollution Dynamics, Department of Environmental System Sciences, CH-8092 Zürich (Switzerland)

    2017-01-15

    Highlights: • Agonistic and antagonistic activity of CMA and CPA were assessed in vitro. • CMA and CPA showed different interaction with human and fish receptors. • No progestogenic but antiandrogenic and antiglucocorticoid activity occurred in fish. • CMA and CPA showed transcriptional changes in zebrafish embryos. • Binary mixtures of the progestins with EE2 were assessed in vitro and in vivo. - Abstract: Synthetic progestins act as endocrine disrupters in fish but their risk to the environment is not sufficiently known. Here, we focused on an unexplored antiandrogenic progestin, chlormadinone acetate (CMA), and the antiandrogenic progestin cyproterone acetate (CPA). The aim was to evaluate whether their in vitro interaction with human and rainbowfish (Melanotaenia fluviatilis) sex hormone receptors is similar. Furthermore, we investigated their activity in zebrafish (Danio rerio) eleuthero-embryos. First, we studied agonistic and antagonistic activities of CMA, CPA, and 17α-ethinylestradiol (EE2), in recombinant yeast expressing either the human progesterone (PGR), androgen (AR), or estrogen receptor. The same compounds were also investigated in vitro in a stable transfection cell system expressing rainbowfish nuclear steroid receptors. For human receptors, both progestins exhibited progestogenic, androgenic and antiestrogenic activity with no antiandrogenic or estrogenic activity. In contrast, interactions with rainbowfish receptors showed no progestogenic, but antiandrogenic, antiglucocorticoid, and some antiestrogenic activity. Thus, interaction with and transactivation of human and rainbowfish PGR and AR were distinctly different. Second, we analyzed transcriptional alterations in zebrafish eleuthero‐embryos at 96 and 144 h post fertilization after exposure to CPA, CMA, EE2, and binary mixtures of CMA and CPA with EE2, mimicking the use in oral contraceptives. CMA led to slight down-regulation of the ar transcript, while CPA down-regulated ar

  17. Manipulating galectin expression in zebrafish (Danio rerio)

    Feng, C.; Nita-Lazar, M.; Gonzalez-Montalban, N.; Wang, J.; Mancini, J.; Ravindran, C.; Ahmed, H.; Vasta, G.R.

    are translational blockers of the Drgal1-L1 and Drgal1-L2, respectively. MO oligos were custom synthesized by Gene Tools ( www.gene-tools.com ). 8. The ZiFiT Targeter Web site ( http://zifi t.partners.org/ ) offers an online option to identify potential target... and disposable tips. 3. PBS (Bio-Rad). 4. Incubator at 28 °C. 5. 15 and 50 ml Conical tube (BD Biosciences). 6. Eppendorf tube (Thermo Scientifi c). 7. ECL Plus detection kit (Amersham Biosciences). 8. Polyclonal antibodies to Drgal1, 3 and 9 were custom...

  18. Early gonad development in zebrafish (Danio rerio)

    SAM

    2014-08-13

    Aug 13, 2014 ... as a relatively larger proportion of proliferating "gonial" germ cells in the latter gonads was considered ... solution in 100 ml tank water) as described by Westerfield (1993). They were ... 90°C hot plate with toluidine blue and thereafter examined and ... morphological sex differentiation, sex differences could.

  19. Learning and memory in zebrafish (Danio rerio).

    Gerlai, R

    2016-01-01

    Learning and memory are defining features of our own species inherently important to our daily lives and to who we are. Without our memories we cease to exist as a person. Without our ability to learn individuals and collectively our society would cease to function. Diseases of the mind still remain incurable. The interest in understanding of the mechanisms of learning and memory is thus well founded. Given the complexity of such mechanisms, concerted efforts have been made to study them under controlled laboratory conditions, ie, with laboratory model organisms. The zebrafish, although new in this field, is one such model organism. The rapidly developing forward- and reverse genetic methods designed for the zebrafish and the increasing use of pharmacological tools along with numerous neurobiology techniques make this species perhaps the best model for the analysis of the mechanisms of complex central nervous system characteristics. The fact that it is an evolutionarily ancient and simpler vertebrate, but at the same time it possesses numerous conserved features across multiple levels of biological organization makes this species an excellent tool for the analysis of the mechanisms of learning and memory. The bottleneck lies in our understanding of its cognitive and mnemonic features, the topic of this chapter. The current paper builds on a chapter published in the previous edition and continues to focus on associative learning, but now it extends the discussion to other forms of learning and to recent discoveries on memory-related features and findings obtained both in adults and larval zebrafish. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish

    Ni Hong

    2016-03-01

    Full Text Available Primordial germ cell (PGC specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes. Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model.

  1. Draft genome of the medaka fish: a comprehensive resource for medaka developmental genetics and vertebrate evolutionary biology.

    Takeda, Hiroyuki

    2008-06-01

    The medaka Oryzias latipes is a small egg-laying freshwater teleost, and has become an excellent model system for developmental genetics and evolutionary biology. The medaka genome is relatively small in size, approximately 800 Mb, and the genome sequencing project was recently completed by Japanese research groups, providing a high-quality draft genome sequence of the inbred Hd-rR strain of medaka. In this review, I present an overview of the medaka genome project including genome resources, followed by specific findings obtained with the medaka draft genome. In particular, I focus on the analysis that was done by taking advantage of the medaka system, such as the sex chromosome differentiation and the regional history of medaka species using single nucleotide polymorphisms as genomic markers.

  2. Oxidative degradation of alkylphenols by horseradish peroxidase.

    Sakuyama, Hisae; Endo, Yasushi; Fujimoto, Kenshiro; Hatana, Yasuhiko

    2003-01-01

    Alkylphenols such as bisphenol A (2,2-bis(4-hydroxyphenyl)propane; BPA), p-nonylphenol (p-NP), and p-octylphenol (p-OP) that are known as endocrine disrupters were oxidized by horseradish (Armoracia rusticana) peroxidase (HRP) with H2O2. The optimal pHs for BPA, p-NP, and p-OP were 8.0, 7.0, and 5.0, respectively. The optimal temperature for BPA was 20 degrees C. Although BPA was rapidly degraded by HRP, its degradation depended on the concentration of HRP. Most of the oxidation products of BPA were polymers, although some 4-isopropenylphenol was produced. When male Japanese medaka (Oryzias latipes) were exposed to BPA, vitellogenin in the blood increased. However, no increased vitellogenin was observed in medaka exposed to HRP-oxidized BPA. The enzymatic oxidation of BPA using HRP was able to eliminate its estrogen-like activity.

  3. Dicty_cDB: Contig-U06086-1 [Dicty_cDB

    Full Text Available 34 1.9 2 ( CT531391 ) A BAC library has been constructed from cultivar ... 34 1.9 3 ( CT536760 ) A BAC lib...u... 36 2.9 2 ( CT504385 ) A BAC library has been constructed from cultivar ... 38 3.0 2 ( BX005275 ) ...1 ( DH327531 ) Oryzias latipes Fosmid clone:GOLWFno690_k15, forw... 46 3.2 1 ( CT562554 ) A BAC library has been constructed from cul...9 ) 16372 Swollen Stolon Solanum tuberosum cDNA, mRNA... 48 0.81 1 ( CK277118 ) EST723196 potato abiotic stress cDNA library... Sola... 48 0.81 1 ( CK277117 ) EST723195 potato abiotic stress cDNA library Sola... 48 0.81

  4. Use of medaka as a tool in studies of radiation effects and chemical carcinogenesis

    Hyodo-Taguchi, Y.; Aoki, K.; Matsudaira, H.

    1982-01-01

    The medaka, Oryzias latipes, a small freshwater oviparous fish, is common in Japan and found in some parts of Asia. Adult fish are 3.0-3.5 cm long and weigh 0.5-0.7 g. The small fish have been used extensively in this laboratory for analysis of radiation effects and for study of chemical carcinogenesis. These fish are relatively easy to rear and their reproductive biology is well known. Recently, inbred strains of the fish have been established by full sister-brother mating. In this report, we will review experimental results using medaka in studies of : 1) radiation effects on spermatogenesis, and 2) induction of hepatic tumors by MAM acetate, we will also review use of medaka in related studies of radiation effects and chemical carcinogenesis. (author)

  5. Biological (molecular and cellular) markers of toxicity

    Shugart, L.R.; D'Surney, S.J.; Gettys-Hull, C.; Greeley, M.S. Jr.

    1991-01-01

    Several molecular and cellular markers of genotoxicity were adapted for measurement in the Medaka (Oryzias latipes), and were used to describe the effects of treatment of the organism with diethylnitrosamine (DEN). NO 6 -ethyl guanine adducts were detected, and a slight statistically significant, increase in DNA strand breaks was observed. These results are consistent with the hypothesis that prolonged exposure to high levels of DEN induced alkyltransferase activity which enzymatically removes any O 6 -ethyl guanine adducts but does not result in strand breaks or hypomethylation of the DNA such as might be expected from excision repair of chemically modified DNA. Following a five week continuous DEN exposure with 100 percent renewal of DEN-water every third day, the F values (DNA double strandedness) increased considerably and to similar extent in fish exposed to 25, 50, and 100 ppM DEN. This has been observed also in medaka exposed to BaP

  6. Instrumental neutron activation analysis of river habitants by the k(0)-standardization method

    Momoshima, N.; Toyoshima, T.; Matsushita, R.; Fukuda, A.; Hibino, K.

    2005-01-01

    Analysis of metal concentrations in samples use reference materials for determination, which means elements out of the references are not possible to be determined. The instrumental neutron activation analysis (INAA) with k(O)-standardization method makes possible to determine metals without use of reference materials, which is very attractive for environmental sample analysis, River habitants would be available as a bio-indicator from which river water quality or metal contamination level could be evaluated. We analyzed river fishes and river insects by INAA with k(O)-standardization to examine the possibility of these habitants as a bio-indicator of water system. Small fishes, Oryzias latipes and Gambusia affinis were collected at 3 different rivers every month and river insects, families of Heptageniidae, Baetidae, Perlidae, Hydropsychidae, Psephenidae were collected at a fixed point of the river. The dried samples were irradiated at the research reactor, JRR-4 (3.5MW), JAERI for 10 min and 3 h. 17 elements (Na, K, Ca, Sc, Cr, Mn, Fe, Co, Zn, As, Se, Br, Rb, Sr, Ba, Ce and Sm) were determined by the NAA-k(0) method, showing effectiveness of the present method for environmental sample analysis. The metals observed in the fishes were the highest in Ca and the lowest in Sc, ranging from 10 5 mg/kg-dry weigh in Ca to 10 -2 mg/kg-dry weight in Sc. The differences in metal concentrations were examined by statistical analysis with t-test. Ca, Na and Br concentrations differ between species, Oryzias latipes and Gambusia, and Fe, Sc, Co, Zn and Se concentrations differ among rivers. No difference was observed on K, Rb and Sr concentrations.

  7. In vivo imaging of the morphology and changes in pH along the gastrointestinal tract of Japanese medaka by photonic band-gap hydrogel microspheres

    Du, Xuemin; Lei, Ngai-Yu; Hu, Peng; Lei, Zhang; Ong, Daniel Hock-Chun; Ge, Xuewu; Zhang, Zhicheng; Lam, Michael Hon-Wah

    2013-01-01

    Graphical abstract: -- Highlights: •Fabrication of pH-responsive photonic colloidal crystalline microspheres. •Specific photonic band-gap responses occurred in the pH range of 4–5. •Remarkably low in vivo toxicity to Japanese medaka (Oryzia latipes). •In vivo imaging of the morphology and pH along GI tract of Japanese medaka. •Demonstrates bio-imaging potentials of stimuli-responsive photonic materials. -- Abstract: Colloidal crystalline microspheres with photonic band-gap properties responsive to media pH have been developed for in vivo imaging purposes. These colloidal crystalline microspheres were constructed from monodispersed core–shell nano-size particles with poly(styrene-co-acrylic acid) (PS-co-PAA) cores and poly(acrylic acid-co-N-isopropylacrylamide) (PAA-co-PNIPAM) hydrogel shells cross-linked by N,N′-methylenebisacrylamide. A significant shift in the photonic band-gap properties of these colloidal crystalline microspheres was observed in the pH range of 4–5. This was caused by the discontinuous volume phase transition of the hydrogel coating, due to the protonation/deprotonation of its acrylic acid moieties, on the core–shell nano-sized particles within the microspheres. The in vivo imaging capability of these pH-responsive photonic microspheres was demonstrated on a test organism – Japanese medaka, Oryzia latipes – in which the morphology and change in pH along their gastrointestinal (GI) tracts were revealed under an ordinary optical microscope. This work illustrates the potential of stimuli-responsive photonic band-gap materials in tissue-/organ-level in vivo bio-imaging

  8. Acute Toxicity Comparison of Single-Walled Carbon Nanotubes in Various Freshwater Organisms

    Eun Kyung Sohn

    2015-01-01

    Full Text Available While the commercialization of single-walled carbon nanotubes (SWCNTs is rapidly expanding, the environmental impact of this nanomaterial is not well understood. Therefore, the present study evaluates the acute aquatic toxicity of SWCNTs towards two freshwater microalgae (Raphidocelis subcapitata and Chlorella vulgaris, a microcrustacean (Daphnia magna, and a fish (Oryzias latipes based on OECD test guidelines (201, 202, and 203. According to the results, the SWCNTs inhibited the growth of the algae R. subcapitata and C. vulgaris with a median effective concentration (EC50 of 29.99 and 30.96 mg/L, respectively, representing “acute category 3” in the Globally Harmonized System (GHS of classification and labeling of chemicals. Meanwhile, the acute toxicity test using O. latipes and D. magna did not show any mortality/immobilizing effects up to a concentration of 100.00 mg/L SWCNTs, indicating no hazard category in the GHS classification. In conclusion, SWCNTs were found to induce acute ecotoxicity in freshwater microalgae, yet not in D. magna and medaka fish.

  9. Genetic similarity of the Hainan medaka populations collected from hyper- and hypo-osmotic environments in northern Vietnam

    Hayakawa, Hideki; Le, Quang Dung; Kinoshita, Masato; Takehana, Yusuke; Sakuma, Kei; Takeshima, Hirohiko; Kojima, Shigeaki; Naruse, Kiyoshi; Inoue, Koji

    2015-06-01

    Ricefishes of the genus Oryzias, including Japanese medaka ( O. latipes), are known as excellent model organisms for studies in various fields of science. Some species of the genus inhabit brackish water, and such species are recognized to be useful to investigate physiological phenomena in seawater. However, only a limited number of species have been recorded from brackish waters. In addition, there is no information about the genetic relationship among populations inhabiting sites with different salinities. Here we report the discovery of Oryzias fish in two locations near Haiphong, northern Vietnam, a brackish mangrove planting area and a freshwater pond. A phylogenetic analysis using mitochondrial 12S and 16S ribosomal RNA (rRNA) gene sequences indicated that the fish from the two localities are the same species, Hainan medaka, O. curvinotus. Population genetic analysis using the mitochondrial 12S and 16S rRNA gene sequences revealed a close genetic relationship between the two populations. These results suggest that O. curvinotus is adaptable to both hyperosmotic and hypoosmotic environments. Due to its osmotic adaptability and ease of rearing in the laboratory, this species is expected to become a model for marine environmental and toxicological studies, as well as for studies of osmotic adaptation mechanisms.

  10. Short-term memory in zebrafish (Danio rerio).

    Jia, Jason; Fernandes, Yohaan; Gerlai, Robert

    2014-08-15

    Learning and memory represent perhaps the most complex behavioral phenomena. Although their underlying mechanisms have been extensively analyzed, only a fraction of the potential molecular components have been identified. The zebrafish has been proposed as a screening tool with which mechanisms of complex brain functions may be systematically uncovered. However, as a relative newcomer in behavioral neuroscience, the zebrafish has not been well characterized for its cognitive and mnemonic features, thus learning and/or memory screens with adults have not been feasible. Here we study short-term memory of adult zebrafish. We show animated images of conspecifics (the stimulus) to the experimental subject during 1 min intervals on ten occasions separated by different (2, 4, 8 or 16 min long) inter-stimulus intervals (ISI), a between subject experimental design. We quantify the distance of the subject from the image presentation screen during each stimulus presentation interval, during each of the 1-min post-stimulus intervals immediately following the stimulus presentations and during each of the 1-min intervals furthest away from the last stimulus presentation interval and just before the next interval (pre-stimulus interval), respectively. Our results demonstrate significant retention of short-term memory even in the longest ISI group but suggest no acquisition of reference memory. Because in the employed paradigm both stimulus presentation and behavioral response quantification is computer automated, we argue that high-throughput screening for drugs or mutations that alter short-term memory performance of adult zebrafish is now becoming feasible. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Behavioral and Metabolic Phenotype Indicate Personality in Zebrafish (Danio rerio)

    Yuan, Mingzhe; Chen, Yan; Huang, Yingying; Lu, Weiqun

    2018-01-01

    Consistency of individual differences of animal behavior and personality in reactions to various environmental stresses among their life stages could reflect basic divergences in coping style which may affect survival, social rank, and reproductive success in the wild. However, the physiological mechanisms determining personality remain poorly understood. In order to study whether behavior, metabolism and physiological stress responses relate to the personality, we employed post-stress recovery assays to separate zebrafish into two behavioral types (proactive and reactive). The results demonstrated consistent difference among personality, behavior and metabolism in which proactive individuals were more aggressive, had higher standard metabolic rates and showed lower shuttled frequencies between dark and light compartments than the reactive ones. The behavioral variations were also linked to divergent acute salinity stress responses: proactive individuals adopted a swift locomotion behavior in response to acute salinity challenge while reactive individuals remain unchanged. Our results provide useful insight into how personality acts on correlated traits and the importance of a holistic approach to understanding the mechanisms driving persistent inter-individual differences. PMID:29899710

  12. Early gonad development in zebrafish ( Danio rerio ) | Okuthe ...

    Gonadogenesis in zebrafish goes through an initial ovarian phase then subsequently into either ovarian or testicular phases. How germ cells choose to commit to an oogenic fate and enter meiosis or alternatively not enter meiosis and commit to a spermatogenetic fate remains a key question. This study investigated events ...

  13. Adrenergic control of swimbladder deflation in the zebrafish (Danio rerio).

    Dumbarton, Tristan C; Stoyek, Matthew; Croll, Roger P; Smith, Frank M

    2010-07-15

    Many teleosts actively regulate buoyancy by adjusting gas volume in the swimbladder. In physostomous fishes such as the zebrafish, a connection is maintained between the swimbladder and the oesophagus via the pneumatic duct for the inflation and deflation of this organ. Here we investigated the role of adrenergic stimulation of swimbladder wall musculature in deflation of the swimbladder. Noradrenaline (NA), the sympathetic neurotransmitter (dosage 10(-6) to 10(-5) mol l(-1)), doubled the force of smooth muscle contraction in isolated tissue rings from the anterior chamber, caused a doubling of pressure in this chamber in situ, and evoked gas expulsion through the pneumatic duct, deflating the swimbladder to approximately 85% of the pre-NA volume. These effects were mediated by beta-adrenergic receptors, representing a novel role for these receptors in vertebrates. No effects of adrenergic stimulation were detected in the posterior chamber. In a detailed examination of the musculature and innervation of the swimbladder to determine the anatomical substrate for these functional results, we found that the anterior chamber contained an extensive ventral band of smooth muscle with fibres organized into putative motor units, richly innervated by tyrosine hydroxylase-positive axons. Additionally, a novel arrangement of folds in the lumenal connective tissue in the wall of the anterior chamber was described that may permit small changes in muscle length to cause large changes in effective wall distensibility and hence chamber volume. Taken together, these data strongly suggest that deflation of the zebrafish swimbladder occurs primarily by beta-adrenergically mediated contraction of smooth muscle in the anterior chamber and is under the control of the sympathetic limb of the autonomic nervous system.

  14. Effects of uranium on the metabolism of zebrafish, Danio rerio

    Augustine, Starrlight; Gagnaire, Béatrice; Adam-Guillermin, Christelle; Kooijman, Sebastiaan A.L.M.

    2012-01-01

    The increasing demand for nuclear energy results in heightened levels of uranium (U) in aquatic systems which present a potential health hazard to resident organisms. The aim of this study was to mechanistically assess how chronic exposure to environmentally relevant concentrations of U perturbs the complex interplay between feeding, growth, maintenance, maturation and reproduction throughout the life-cycle of an individual. To this end we analysed literature-based and original zebrafish toxicity data within a same mass and energy balancing conceptual framework. U was found to increase somatic maintenance leading to inhibition of spawning as well as increase hazard rate and costs for growth during the early life stages. The fish's initial conditions and elimination through reproduction greatly affected toxico-kinetics and effects. We demonstrate that growth and reproduction should be measured on specific individuals since mean values were hardly interpretable. The mean food level differed between experiments, conditions and individuals. This last ‘detail’ contributed substantially to the observed variability by its combined effect on metabolism, toxic effects and toxico-kinetics. The significance of this work is that we address exactly how these issues are related and derive conclusions which are independent of experimental protocol and coherent with a very large body of literature on zebrafish eco-physiology.

  15. Transformation of tributyltin in zebrafish eleutheroembryos (Danio rerio).

    Borges, Aline Rocha; López-Serrano Oliver, Ana; Gallego-Gallegos, Mercedes; Muñoz-Olivas, Riansares; Rodrigues Vale, Maria Goreti; Cámara, Carmen

    2014-12-01

    Organotin compounds are highly versatile group of organometallic chemicals used in industrial and agricultural applications. Their endocrine-disrupting effects are well known and their extensive uses as biocide materials, e.g., in antifouling paints, for many years have led to serious environmental problems. So far, attention has mainly been given to tributyltin pollution in water, sediments, and marine organisms because of its highly toxic effects and high accumulation levels at very low concentrations. In this study, we will focus on the conversion of tributyltin after it is absorbed by zebrafish eleutheroembryos, presented here as an alternative model to adult fish for describing bioconcentration. A simplified analytical extraction procedure based on the use of an assisted ultrasonic probe and derivatization by ethylation, followed by gas chromatography with a flame photometric detector (GC-FPD) is proposed. This classical methodology for organotin determination has been validated by inductively coupled plasma mass spectrometry (ICP-MS) and Zeeman graphite furnace atomic absorption spectrometry (ZGF-AAS) in terms of total tin content. The speciation analysis results show that zebrafish eleutheroembryos absorb high amounts of tributyltin and convert it into monobutyltin and likely in inorganic tin.

  16. Silver nanoparticles enhance wound healing in zebrafish (Danio rerio).

    Seo, Seung Beom; Dananjaya, S H S; Nikapitiya, Chamilani; Park, Bae Keun; Gooneratne, Ravi; Kim, Tae-Yoon; Lee, Jehee; Kim, Cheol-Hee; De Zoysa, Mahanama

    2017-09-01

    Silver nanoparticles (AgNPs) were successfully synthesized by a chemical reduction method, physico-chemically characterized and their effect on wound-healing activity in zebrafish was investigated. The prepared AgNPs were circular-shaped, water soluble with average diameter and zeta potential of 72.66 nm and -0.45 mv, respectively. Following the creation of a laser skin wound on zebrafish, the effect of AgNPs on wound-healing activity was tested by two methods, direct skin application (2 μg/wound) and immersion in a solution of AgNPs and water (50 μg/L). The zebrafish were followed for 20 days post-wounding (dpw) by visual observation of wound size, calculating wound healing percentage (WHP), and histological examination. Visually, both direct skin application and immersion AgNPs treatments displayed clear and faster wound closure at 5, 10 and 20 dpw compared to the controls, which was confirmed by 5 dpw histology data. At 5 dpw, WHP was highest in the AgNPs immersion group (36.6%) > AgNPs direct application group (23.7%) > controls (18.2%), showing that WHP was most effective in fish immersed in AgNPs solution. In general, exposure to AgNPs induced gene expression of selected wound-healing-related genes, namely, transforming growth factor (TGF-β), matrix metalloproteinase (MMP) -9 and -13, pro-inflammatory cytokines (IL-1β and TNF-α) and antioxidant enzymes (superoxide dismutase and catalase), which observed differentiation at 12 and 24 h against the control; but the results were not consistently significant, and many either reached basal levels or were down regulated at 5 dpw in the wounded muscle. These results suggest that AgNPs are effective in acceleration of wound healing and altered the expression of some wound-healing-related genes. However, the detailed mechanism of enhanced wound healing remains to be investigated in fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Effects of uranium on the metabolism of zebrafish, Danio rerio

    Augustine, Starrlight, E-mail: starr-light.augustine@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Gagnaire, Beatrice, E-mail: beatrice.gagnaire@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Kooijman, Sebastiaan A.L.M., E-mail: bas.kooijman@vu.nl [Department of Theoretical Biology, Vrije Universiteit, de Boelelaan 1087, 1081 HV Amsterdam (Netherlands)

    2012-08-15

    The increasing demand for nuclear energy results in heightened levels of uranium (U) in aquatic systems which present a potential health hazard to resident organisms. The aim of this study was to mechanistically assess how chronic exposure to environmentally relevant concentrations of U perturbs the complex interplay between feeding, growth, maintenance, maturation and reproduction throughout the life-cycle of an individual. To this end we analysed literature-based and original zebrafish toxicity data within a same mass and energy balancing conceptual framework. U was found to increase somatic maintenance leading to inhibition of spawning as well as increase hazard rate and costs for growth during the early life stages. The fish's initial conditions and elimination through reproduction greatly affected toxico-kinetics and effects. We demonstrate that growth and reproduction should be measured on specific individuals since mean values were hardly interpretable. The mean food level differed between experiments, conditions and individuals. This last 'detail' contributed substantially to the observed variability by its combined effect on metabolism, toxic effects and toxico-kinetics. The significance of this work is that we address exactly how these issues are related and derive conclusions which are independent of experimental protocol and coherent with a very large body of literature on zebrafish eco-physiology.

  18. Cryopreservation of zebrafish (Danio rerio) oocytes by vitrification.

    Guan, M; Rawson, D M; Zhang, T

    2010-01-01

    Cryopreservation of fish oocytes is challenging because these oocytes have low membrane permeability to water and cryoprotectant and are highly chilling sensitive. Vitrification is considered to be a promising approach for their cryopreservation as it involves rapid freezing and thawing of the oocytes and therefore minimising the chilling injury. In the present study, vitrification properties and the toxicity of a range of vitrification solutions containing different concentrations of Me2SO, methanol, propylene glycol and ethylene glycol were investigated. Two different base media and vitrification methods were compared. The effect of different post-thaw dilution solutions together with incubation periods on oocyte viability were also investigated. Stage III zebrafish oocytes were equilibrated in increasing concentrations of cryoprotectants for 30 min in 3 steps. Oocytes were thawed rapidly in a water bath and cryoprotectants were removed in 4 steps. Oocyte viability was assessed using trypan blue staining. The results showed that vitrification solutions V3 and V4 in KCl buffer had low toxicity and vitrified well. The survivals of oocytes after stepwise dilution using solutions containing permeable cryoprotectants were significant higher than those diluted in 0.5M glucose, and the use of CVA65 vitrification system improved oocyte survival when compared with plastic straws after 30 min at 22 degrees C post-thawing. Cryopreservation of zebrafish oocytes by vitrification is reported here for the first time, although oocyte survivals after cryopreservation assessed by trypan blue staining were relatively high shortly after thawing, they became swollen and translucent after incubation in KCl buffer. Further studies are needed to optimise the post-thaw culturing conditions.

  19. Infection and immunity against Ichthyophthirius multifiliis in zebrafish (Danio rerio)

    Jørgensen, Louise von Gersdorff

    2016-01-01

    Ichthyophthirius multifiliis, causing white spot disease, is a serious pathogen in aquaculture as well as for the ornamental fish industry. In carp, channel catfish and rainbow trout the immune responses against the parasite have been partly elucidated and these species are able to acquire a high...

  20. Developmental mechanisms of arsenite toxicity in zebrafish (Danio rerio) embryos

    Li Dan; Lu Cailing; Wang Ju; Hu Wei; Cao Zongfu; Sun Daguang; Xia Hongfei; Ma Xu

    2009-01-01

    Arsenic usually accumulates in soil, water and airborne particles, from which it is taken up by various organisms. Exposure to arsenic through food and drinking water is a major public health problem affecting some countries. At present there are limited laboratory data on the effects of arsenic exposure on early embryonic development and the mechanisms behind its toxicity. In this study, we used zebrafish as a model system to investigate the effects of arsenite on early development. Zebrafish embryos were exposed to a range of sodium arsenite concentrations (0-10.0 mM) between 4 and 120 h post-fertilization (hpf). Survival and early development of the embryos were not obviously influenced by arsenite concentrations below 0.5 mM. However, embryos exposed to higher concentrations (0.5-10.0 mM) displayed reduced survival and abnormal development including delayed hatching, retarded growth and changed morphology. Alterations in neural development included weak tactile responses to light (2.0-5.0 mM, 30 hpf), malformation of the spinal cord and disordered motor axon projections (2.0 mM, 48 hpf). Abnormal cardiac function was observed as bradycardia (0.5-2.0 mM, 60 hpf) and altered ventricular shape (2.0 mM, 48 hpf). Furthermore, altered cell proliferation (2.0 mM, 24 hpf) and apoptosis status (2.0 mM, 24 and 48 hpf), as well as abnormal genomic DNA methylation patterning (2.0 mM, 24 and 48 hpf) were detected in the arsenite-treated embryos. All of these indicate a possible relationship between arsenic exposure and developmental failure in early embryogenesis. Our studies suggest that the negative effects of arsenic on vertebrate embryogenesis are substantial

  1. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma.

    Wang, Jian; Wang, Wen-Xiong

    2016-05-24

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0-640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6-18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3-15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046-0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71-1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09-2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88-0.90 μg/g/d.

  2. Natriuretic peptides in developing medaka embryos: implications in cardiac development by loss-of-function studies.

    Miyanishi, Hiroshi; Okubo, Kataaki; Nobata, Shigenori; Takei, Yoshio

    2013-01-01

    Cardiac natriuretic peptides (NPs), atrial NP (ANP) and B-type NP (BNP), and their receptor, guanylyl cyclase (GC)-A have attracted attention of many basic and clinical researchers because of their potent renal and cardiovascular actions. In this study, we used medaka, Oryzias latipes, as a model species to pursue the physiological functions of NPs because it is a suitable model for developmental analyses. Medaka has two ligands, BNP and C-type NP3 (CNP3) (but not ANP), that have greater affinity for the two O. latipes GC-A receptors (OLGC), OLGC7 and OLGC2, respectively. CNP3 is the ancestral molecule of cardiac NPs. Initially, we examined developmental expression of cardiac NP/receptor combinations, BNP/OLGC7 and CNP3/OLGC2, using quantitative real-time PCR and in situ hybridization. BNP and CNP3 mRNA increased at stages 25 (onset of ventricular formation) and 22 (appearance of heart anlage), respectively, whereas both receptor mRNAs increased at as early as stage 12. BNP/OLGC7 transcripts were found in arterial/ventricular tissues and CNP3/OLGC2 transcripts in venous/atrial tissues by in situ hybridization. Thus, BNP and CNP3 can act locally on cardiac myocytes in a paracrine/autocrine fashion. Double knockdown of BNP/OLGC7 genes impaired ventricular development by causing hypoplasia of ventricular myocytes as evidenced by reduced bromodeoxyuridine incorporation. CNP3 knockdown induced hypertrophy of atria and activated the renin-angiotensin system. Collectively, it appears that BNP is important for normal ventricular, whereas CNP3 is important for normal atrial development and performance, a role usually taken by ANP in other vertebrates. The current study provides new insights into the role of cardiac NPs in cardiac development in vertebrates.

  3. Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka.

    Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

    2015-10-28

    Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. Copyright © 2015 Kawajiri et al.

  4. Residue analyses on 2-amino-4-phenylthiazole, a piscine anesthetic, in fishes, 3

    Suzuki, Akira; Shimura, Masaru; Kikuchi, Takahiko; Sekizawa, Yasuharu

    1977-01-01

    The major biotransformation product of 2-amino-phenylthiazole in rainbow trout (Salmo gairdneri irideus) was isolated from water following exposure of fish to the anesthetic. The isolated crystalline metabolite was shown by means of ultraviolet, infrared and optical rotatory dispersion spectroscopy and gas chromatography to be identical to 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid, the major biotransformation product previously found in medaka (killifish, Oryzias latipes). The major biotransformation product in carp (Cyprinus carpio) was also identified as 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid by molecular sieve, thin layer and gas chromatography. Conversion of 2-amino-4-phenylthiazole to the N-glycuronyl conjugate was 8 and 12%, respectively, in rainbow trout and carp as shown by thin layer chromatography of extracts from fish treated with 3 H-labeled anesthetic. In addition, a minor metabolite of the anesthetic in rainbow trout was isolated as a yellowish-white crystalline powder and identified as 2-acetamino-4-(4'-hydroxyphenyl)-thiazole by means of ultraviolet and infrared spectroscopy, NMR and mass spectrometry. Chromatography suggested that this same metabolite was also formed in carp but in concentrations too low for isolation and definitive identification. (auth.)

  5. Neurological effects on startle response and escape from predation by medaka exposed to organic chemicals

    Carlson, R.; Drummond, R.; Hammermeister, D.; Bradbury, S. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1995-12-31

    Simultaneous electrophysiological and behavioral studies were performed on juvenile Japanese medaka (Oryzias latipes) exposed to representative neurotoxic organic chemicals at sublethal concentrations. Non-invasive recordings were made of the electrical impulses generated within giant neuronal Mauthner cells, associated interneurons or motoneurons, and musculature, all of which initiate the startle or escape response in fish. Timing in milliseconds between these electrical sequelae was measured for each fish before and at 24 and 48 hours exposure to a chemical. Also noted was the number of startle responses to number of stimuli ratio (R/S). Other groups of medaka were fed to bluegills and consumption times recorded to assess their ability to escape predation. These results were compared to neurophysiological effect levels. Phenol, 2,4-dinitrophenol, chlorpyrifos, fenvalerate, and 1-octanol impaired the ability of medaka to escape predation at all concentrations. Medaka were more susceptible to predation in high concentrations of carbaryl and strychnine, but less susceptible at low concentrations, whereas the reverse was true for endosulfan. The variety of neurological effects detected at these concentrations suggest that different mechanisms may be responsible. Phenol and strychnine affected Mauthner cell to motoneuron transmission, chlorpyrifos and carbaryl showed neuromuscular effects, and R/S was affected by most chemicals. Although a variety of neurotoxic mechanisms were examined, the exposure threshold for significant effects for each specific compound was found to be consistent for both the neurophysiological and behavioral endpoints.

  6. Construction of the High-Density Genetic Linkage Map and Chromosome Map of Large Yellow Croaker (Larimichthys crocea

    Jingqun Ao

    2015-11-01

    Full Text Available High-density genetic maps are essential for genome assembly, comparative genomic analysis and fine mapping of complex traits. In this study, 31,191 single nucleotide polymorphisms (SNPs evenly distributed across the large yellow croaker (Larimichthys crocea genome were identified using restriction-site associated DNA sequencing (RAD-seq. Among them, 10,150 high-confidence SNPs were assigned to 24 consensus linkage groups (LGs. The total length of the genetic linkage map was 5451.3 cM with an average distance of 0.54 cM between loci. This represents the densest genetic map currently reported for large yellow croaker. Using 2889 SNPs to target specific scaffolds, we assigned 533 scaffolds, comprising 421.44 Mb (62.04% of the large yellow croaker assembled sequence, to the 24 linkage groups. The mapped assembly scaffolds in large yellow croaker were used for genome synteny analyses against the stickleback (Gasterosteus aculeatus and medaka (Oryzias latipes. Greater synteny was observed between large yellow croaker and stickleback. This supports the hypothesis that large yellow croaker is more closely related to stickleback than to medaka. Moreover, 1274 immunity-related genes and 195 hypoxia-related genes were mapped to the 24 chromosomes of large yellow croaker. The integration of the high-resolution genetic map and the assembled sequence provides a valuable resource for fine mapping and positional cloning of quantitative trait loci associated with economically important traits in large yellow croaker.

  7. Evaluation of wastewater reclamation technologies based on in vitro and in vivo bioassays

    Cao Nan; Yang Min; Zhang Yu; Hu Jianying; Ike, Michihiko; Hirotsuji, Junji; Matsui, Hisae; Inoue, Daisuke; Sei, Kazunari

    2009-01-01

    When municipal secondary effluent is used as the main supplementation water source for surface water bodies, its potential adverse ecological effects should not be neglected. The objective of this work was to investigate the effectiveness of several technologies, i.e. combination of coagulation and sand filtration (CSF), ultraviolet (UV) irradiation, chlorination, ozonation, ultrafiltration (UF) and reverse osmosis filtration (RO), on the removal of acute ecotoxicity, genotoxicity and retinoic acid receptor (RAR) agonist activity from the municipal secondary effluent. The effects of treated effluents on the development of Japanese medaka (Oryzias latipes) embryos were also evaluated. The secondary effluent exhibited a mutagenic effect on Salmonella typhimurium strain TA 1535/pSK1002, acute invertebrate toxicity to Daphnia magna, and weak RAR α activity. RO and ozonation demonstrated remarkable removals of the genotoxic effect, acute toxicity and RAR activity from secondary effluent, while chlorination could elevate both genotoxicity and acute toxicity. CSF, UV, UF, chlorination as well as RO could decrease the 4-day mortality of medaka embryos and accordingly increase the hatching success rate, comparing with the secondary effluent. Ozonation at 4 mg/l and higher doses, however, elicited significantly higher 4-day mortality, leading to the reduction of the hatching success rate

  8. Inherited XX sex reversal originating from wild medaka populations.

    Shinomiya, A; Otake, H; Hamaguchi, S; Sakaizumi, M

    2010-11-01

    The teleost fish, medaka (Oryzias latipes), has an XX/XY sex-determining mechanism. A Y-linked DM domain gene, DMY, has been isolated by positional cloning as the sex-determining gene in this species. Previously, we conducted a field survey of genotypic sex and found that approximately 1% of wild medaka are sex-reversed (XX males and XY females). Here, we performed genetic analyses of nine spontaneous XX sex-reversed males to elucidate its genetic basis. In all cases, the F(1) progeny were all females, whereas XX males reappeared in the backcross (BC) progeny, suggesting that XX sex reversal is a recessive trait. Although the incidences of sex reversal in the BC progeny were mostly low, 40% were males derived from one XX male. We performed linkage analysis using 55 BC males and located a single major factor, sda-1 (sex-determining autosomal factor-1), controlling sex reversal in an autosomal linkage group. Thus, genes involved in the sex-determining pathway can be isolated from spontaneous mutants in wild populations.

  9. Toxicity of tetramethylammonium hydroxide to aquatic organisms and its synergistic action with potassium iodide.

    Mori, Izumi C; Arias-Barreiro, Carlos R; Koutsaftis, Apostolos; Ogo, Atsushi; Kawano, Tomonori; Yoshizuka, Kazuharu; Inayat-Hussain, Salmaan H; Aoyama, Isao

    2015-02-01

    The aquatic ecotoxicity of chemicals involved in the manufacturing process of thin film transistor liquid crystal displays was assessed with a battery of four selected acute toxicity bioassays. We focused on tetramethylammonium hydroxide (TMAH, CAS No. 75-59-2), a widely utilized etchant. The toxicity of TMAH was low when tested in the 72 h-algal growth inhibition test (Pseudokirchneriellia subcapitata, EC50=360 mg L(-1)) and the Microtox® test (Vibrio fischeri, IC50=6.4 g L(-1)). In contrast, the 24h-microcrustacean immobilization and the 96 h-fish mortality tests showed relatively higher toxicity (Daphnia magna, EC50=32 mg L(-1) and Oryzias latipes, LC50=154 mg L(-1)). Isobologram and mixture toxicity index analyses revealed apparent synergism of the mixture of TMAH and potassium iodide when examined with the D. magna immobilization test. The synergistic action was unique to iodide over other halide salts i.e. fluoride, chloride and bromide. Quaternary ammonium ions with longer alkyl chains such as tetraethylammonium and tetrabutylammonium were more toxic than TMAH in the D. magna immobilization test. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. FY 1983 report on the results of the verification test on the methanol conversion for oil-fired power plant. Part 1. Verification test on the environmental safety; 1983 nendo sekiyu karyoku hatsudensho metanoru tenkan tou jissho shiken seika hokokusho. Kankyo anzensei jissho shiken (Sono 1)

    NONE

    1984-03-01

    As to the verification test on the environmental safety in the use of methanol as power generation use fuel, the following were summed up: review of the verification test and the interim evaluation, state of implementation of the FY 1983 verification test, study/evaluation of the results of the FY 1983 test, survey of research trends, plan of the FY 1984 verification test, record of the committee, etc. Concerning the interim evaluation, high evaluation was obtained as described below: Testing facilities were constructed as planned at first to make the implementation of various tests possible; Tests were smoothly conducted, and among the acute test using monkey, test on mock flue gas using monkey/rat, test on mutagenicity and test on the effect on aquatic animals, tests using oryzias latipes and abalone on the fatal concentration, avoidance behavior and chronic effect were finished by the end of FY 1983 almost as planned; The long-term inhalation test using monkey and rat/mouse has been smoothly in progress. In the survey of research trends, the paper introduced the outlined literature on the methanol metabolism of monkey, changes in the methanol concentration in blood/urine in the case of drinking methanol by mistake. (NEDO)

  11. Acquisition of glial cells missing 2 enhancers contributes to a diversity of ionocytes in zebrafish.

    Takanori Shono

    Full Text Available Glial cells missing 2 (gcm2 encoding a GCM-motif transcription factor is expressed in the parathyroid in amniotes. In contrast, gcm2 is expressed in pharyngeal pouches (a homologous site of the parathyroid, gills, and H(+-ATPase-rich cells (HRCs, a subset of ionocytes on the skin surface of the teleost fish zebrafish. Ionocytes are specialized cells that are involved in osmotic homeostasis in aquatic vertebrates. Here, we showed that gcm2 is essential for the development of HRCs and Na(+-Cl(- co-transporter-rich cells (NCCCs, another subset of ionocytes in zebrafish. We also identified gcm2 enhancer regions that control gcm2 expression in ionocytes of zebrafish. Comparisons of the gcm2 locus with its neighboring regions revealed no conserved elements between zebrafish and tetrapods. Furthermore, We observed gcm2 expression patterns in embryos of the teleost fishes Medaka (Oryzias latipes and fugu (Fugu niphobles, the extant primitive ray-finned fishes Polypterus (Polypterus senegalus and sturgeon (a hybrid of Huso huso × Acipenser ruhenus, and the amphibian Xenopus (Xenopus laevis. Although gcm2-expressing cells were observed on the skin surface of Medaka and fugu, they were not found in Polypterus, sturgeon, or Xenopus. Our results suggest that an acquisition of enhancers for the expression of gcm2 contributes to a diversity of ionocytes in zebrafish during evolution.

  12. Cloning and characterization of transferrin cDNA and rapid detection of transferrin gene polymorphism in rainbow trout (Oncorhynchus mykiss).

    Tange, N; Jong-Young, L; Mikawa, N; Hirono, I; Aoki, T

    1997-12-01

    A cDNA clone of rainbow trout (Oncorhynchus mykiss) transferrin was obtained from a liver cDNA library. The 2537-bp cDNA sequence contained an open reading frame encoding 691 amino acids and the 5' and 3' noncoding regions. The amino acid sequences at the iron-binding sites and the two N-linked glycosylation sites, and the cysteine residues were consistent with known, conserved vertebrate transferrin cDNA sequences. Single N-linked glycosylation sites existed on the N- and C-lobe. The deduced amino acid sequence of the rainbow trout transferrin cDNA had 92.9% identities with transferrin of coho salmon (Oncorhynchus kisutch); 85%, Atlantic salmon (Salmo salar); 67.3%, medaka (Oryzias latipes); 61.3% Atlantic cod (Gadus morhua); and 59.7%, Japanese flounder (Paralichthys olivaceus). The long and accurate polymerase chain reaction (LA-PCR) was used to amplify approximately 6.5 kb of the transferrin gene from rainbow trout genomic DNA. Restriction fragment length polymorphisms (RFLPs) of the LA-PCR products revealed three digestion patterns in 22 samples.

  13. An in vivo model fish system to test chemical effects on sexual differentiation and development: exposure to ethinyl estradiol

    Papoulias, Diana M.; Noltie, Douglas B.; Tillitt, Donald E.

    2000-01-01

    A model system was characterized which may be used as an in vivo screen for effects of chemicals or environmental mixtures on sexual differentiation and development of reproductive organs and gametes. We evaluated the effects of a model environmental estrogen, ethinyl estradiol (EE2), on the d-rR strain of medaka, Oryzias latipes, using a nano-injection exposure. Gonad histopathology indicated that a single injection of 0.5–2.5 ng EE2/egg can cause phenotypic sex-reversal of genetic males to females. Sex-reversals could be detected as early as 7 days post-hatch. Sex-reversed males had female-typical duct development and the secondary sex characteristics we measured were generally consistent with phenotype, with the exception of a few EE2-exposed XX and XY females which possessed ambiguous anal fins. Using discriminant analysis, we determined that the presence or absence of the secondary sex characteristic, a dorsal fin notch, was a very reliable indicator of gonadal sex. No instances of gonadal intersexes were observed. Ethinyl estradiol also appeared to reduce growth but not condition (weight-at-length) and exposed XX females appeared to have a higher incidence of atretic follicles relative to controls. Our results suggest that estrogenic chemicals may influence sexual differentiation and development and that the medaka model is well suited to assessing these effects.

  14. Predicting bioavailability and accumulation of organochlorine pesticides by Japanese medaka in the presence of humic acid and natural organic matter using passive sampling membranes.

    Ke, Runhui; Luo, Jianping; Sun, Liwei; Wang, Zijian; Spear, Philip A

    2007-10-01

    Adsorption to dissolved organic matter (DOM) may significantly decrease the freely dissolved concentration of many hydrophobic organic compounds and, hence, result in reduced bioavailability to aquatic organisms. Here, the suitability of using triolein-embedded cellulose acetate membrane (TECAM) as a biomimetic surrogate to assess the bioavailability of organochlorine pesticides (OCPs) in water in the presence of DOM was explored. The accumulation of OCPs was measured in TECAM and pelagic Japanese medaka (Oryzias latipes) in the laboratory after 12 h exposure to water containing different levels of Aldrich humic acid. Further, OCP uptake by TECAM and medaka in real aqueous environments was evaluated after 30 d exposures in two sites. Laboratory results showed that OCP uptake by medaka consistently decreased with increasing levels of humic acid in the range of 0-15 mg C/L in sample solutions. This tendency was closely mimicked by OCP accumulation in TECAM under the same conditions. Field results showed that TECAM accumulated similar OCP patterns as medaka (r2 = 0.92 for site 1 and r2 = 0.94 for site 2), although comparison of the in-field eight OCP concentrations in TECAM to those in medaka yielded approximately a factor of 3 (on a wet weight basis). These results suggest that the TECAM method can be used as a simple and useful tool to predict the bioavailability and bioaccumulation potential of poorly biotransformed organic compounds in pelagic fish in aqueous environment.

  15. Accumulation of tritium in aquatic organisms through a food chain with three trophic levels

    Komatsu, Kenshi; Higuchi, Masataka; Sakka, Masatoshi

    1981-01-01

    Accumulation of tritium in aquatic organisms was estimated through a model food chain such as; tritiated water (THO) → diatoms → brine shrimps → Japanese killifish. Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where tritium accumulation took place from tritiated water without tritiated diets. Brine shrimps and Japanese killifish, which grew from larvae to adult in tritiated sea water with feeding on tritiated diets (model food chain), had the R value at 0.70 and 0.67 respectively, indicating that more tritium accumulation in consumer populations with tritiated diets than those without tritiated diets. In addition, the R values of each organ of Japanese killifish, of DNA and the nucleotides purified from brine shrimps growing under the condition with or without our model food chain were measured to estimate the tritium distribution in the body or various components of the organism. These results did not indicate the seeking characteristic of tritium to some specific organs of compounds. (author)

  16. Accumulation of tritium in aquatic organisms through a food chain with three trophic levels

    Komatsu, K.; Higuchi, M.; Sakka, M. (Tohoku Univ., Sendai (Japan). School of Medicine)

    1981-06-01

    Accumulation of tritium in aquatic organisms was estimated through a model food chain such as; tritiated water (THO) ..-->.. diatoms ..-->.. brine shrimps ..-->.. Japanese killifish. Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (..mu..Ci/gH) to that in water (..mu..Ci/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where tritium accumulation took place from tritiated water without tritiated diets. Brine shrimps and Japanese killifish, which grew from larvae to adult in tritiated sea water with feeding on tritiated diets (model food chain), had the R value at 0.70 and 0.67 respectively, indicating that more tritium accumulation in consumer populations with tritiated diets than those without tritiated diets. In addition, the R values of each organ of Japanese killifish, of DNA and the nucleotides purified from brine shrimps growing under the condition with or without our model food chain were measured to estimate the tritium distribution in the body or various components of the organism. These results did not indicate the seeking characteristic of tritium to some specific organs of compounds.

  17. Use of multi-photon laser-scanning microscopy to describe the distribution of xenobiotic chemicals in fish early life stages

    Hornung, Michael W.; Cook, Philip M.; Flynn, Kevin M.; Lothenbach, Doug B.; Johnson, Rodney D.; Nichols, John W.

    2004-01-01

    To better understand the mechanisms by which persistent bioaccumulative toxicants (PBTs) produce toxicity during fish early life stages (ELS), dose-response relationships need to be understood in relation to the dynamic distribution of chemicals in sensitive tissues. In this study, a multi-photon laser scanning microscope (MPLSM) was used to determine the multi-photon excitation spectra of several polyaromatic hydrocarbons (PAHs) and to describe chemical distribution among tissues during fish ELS. The multi-photon excitation spectra revealed intense fluorescent signal from the model fluorophore, pentamethyl-difluoro-boro-indacene (BODIPY[reg], less signal from benzo[a]pyrene and fluoranthene, and no detectable signal from pyrene. The imaging method was tested by exposing newly fertilized medaka (Oryzias latipes) eggs to BODIPY[reg] or fluoranthene for 6 h, followed by transfer to clean media. Embryos and larvae were then imaged through 5 days post-hatch. The two test chemicals partitioned similarly throughout development and differences in fluorescence intensity among tissues were evident to a depth of several hundred microns. Initially, the most intense signal was observed in the oil droplet within the yolk, while a moderate signal was seen in the portion of the yolk containing the yolk-platelets. As embryonic development progressed, the liver biliary system, gall bladder, and intestinal tract accumulated strong fluorescent signal. After hatch, once the gastrointestinal tract was completely developed, most of the fluorescent signal was cleared. The MPLSM is a useful tool to describe the tissue distribution of fluorescent PBTs during fish ELS

  18. A conserved non-reproductive GnRH system in chordates.

    Takehiro G Kusakabe

    Full Text Available Gonadotropin-releasing hormone (GnRH is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.

  19. Diversity of Active States in TMT Opsins.

    Kazumi Sakai

    Full Text Available Opn3/TMT opsins belong to one of the opsin groups with vertebrate visual and non-visual opsins, and are widely distributed in eyes, brains and other internal organs in various vertebrates and invertebrates. Vertebrate Opn3/TMT opsins are further classified into four groups on the basis of their amino acid identities. However, there is limited information about molecular properties of these groups, due to the difficulty in preparing the recombinant proteins. Here, we successfully expressed recombinant proteins of TMT1 and TMT2 opsins of medaka fish (Oryzias latipes in cultured cells and characterized their molecular properties. Spectroscopic and biochemical studies demonstrated that TMT1 and TMT2 opsins functioned as blue light-sensitive Gi/Go-coupled receptors, but exhibited spectral properties and photo-convertibility of the active state different from each other. TMT1 opsin forms a visible light-absorbing active state containing all-trans-retinal, which can be photo-converted to 7-cis- and 9-cis-retinal states in addition to the original 11-cis-retinal state. In contrast, the active state of TMT2 opsin is a UV light-absorbing state having all-trans-retinal and does not photo-convert to any other state, including the original 11-cis-retinal state. Thus, TMT opsins are diversified so as to form a different type of active state, which may be responsible for their different functions.

  20. Ichthyofauna of the Kubo, Tochikura, and Ichinono river systems (Kitakami River drainage, northern Japan), with a comparison of predicted and surveyed species richness

    Nakae, Masanori; Senou, Hiroshi

    2014-01-01

    Abstract The potential fish species pool of the Kubo, Tochikura, and Ichinono river systems (tributaries of the Iwai River, Kitakami River drainage), Iwate Prefecture, northern Japan, was compared with the observed ichthyofauna by using historical records and new field surveys. Based on the literature survey, the potential species pool comprised 24 species/subspecies but only 20, including 7 non-native taxa, were recorded during the fieldwork. The absence during the survey of 11 species/subspecies from the potential species pool suggested either that sampling effort was insufficient, or that accurate determination of the potential species pool was hindered by lack of biogeographic data and ecological data related to the habitat use of the species. With respect to freshwater fish conservation in the area, Lethenteron reissneri, Carassius auratus buergeri, Pseudorasbora pumila, Tachysurus tokiensis, Oryzias latipes, and Cottus nozawae are regarded as priority species, and Cyprinus rubrofuscus, Pseudorasbora parva, and Micropterus salmoides as targets for removal. PMID:25425932

  1. Species comparison of inflammatory cell reactivity

    Boncavage-Hennessey, E.M.; Twerdok, L.E. [Geo-Centers, Inc., Frederick, MD (United States); Finch, R.A.; Gardner, H.S. [Army Biomedical Research and Development Lab., Frederick, MD (United States)

    1994-12-31

    In comparison to the use of rodent models, the use of fish as a potential model to predict immune dysfunction in response to environmental contaminants is a relatively new concept. The development of a fish model for immunotoxicity is possible due to the phylogenetic conservation of many immune functions. The authors have compared mononuclear cell reactivity following in vitro stimulation among five species; Japanese medaka (Oryzias latipes), rainbow trout (Oncorhynchus mykiss), DBA/2 mice, Sprague-Dawley rats and human ML-1 cells. Mononuclear cells were isolated from the rodent bone marrow and from the teleost anterior kidney (the cell population which most closely resembles mammalian hematopoietic tissue). ML-1 cells are a myeloblastic cell line that were differentiated in vitro to monocytes/macrophages. Cell populations were characterized by myeloperoxidase and nonspecific esterase staining characteristic. Reactive oxidant production following in vitro stimulation by phorbol ester was measured using the following methods: reduction of cytochrome c (detection of extracellular superoxide), reduction of nitroblue tetrazolium (detection of intracellular superoxide) and oxidation of phenol red in the presence of horseradish peroxidase (hydrogen peroxide production). In general, teleost cells demonstrated higher superoxide anion production and mammalian cells produced higher quantities of hydrogen peroxide.

  2. hebp3, a novel member of the heme-binding protein gene family, is expressed in the medaka meninges with higher abundance in females due to a direct stimulating action of ovarian estrogens.

    Nakasone, Kiyoshi; Nagahama, Yoshitaka; Okubo, Kataaki

    2013-02-01

    The brains of teleost fish exhibit remarkable sexual plasticity throughout their life span. To dissect the molecular basis for the development and reversal of sex differences in the teleost brain, we screened for genes differentially expressed between sexes in the brain of medaka (Oryzias latipes). One of the genes identified in the screen as being preferentially expressed in females was found to be a new member of the heme-binding protein gene family that includes hebp1 and hebp2 and was designated here as hebp3. The medaka hebp3 is expressed in the meninges with higher abundance in females, whereas there is no expression within the brain parenchyma. This female-biased expression of hebp3 is not attributable to the direct action of sex chromosome genes but results from the transient and reversible action of estrogens derived from the ovary. Moreover, estrogens directly activate the transcription of hebp3 via a palindromic estrogen-responsive element in the hebp3 promoter. Taken together, our findings demonstrate that hebp3 is a novel transcriptional target of estrogens, with female-biased expression in the meninges. The definite but reversible sexual dimorphism of the meningeal hebp3 expression may contribute to the development and reversal of sex differences in the teleost brain.

  3. Spontaneous germline excision of Tol1, a DNA-based transposable element naturally occurring in the medaka fish genome.

    Watanabe, Kohei; Koga, Hajime; Nakamura, Kodai; Fujita, Akiko; Hattori, Akimasa; Matsuda, Masaru; Koga, Akihiko

    2014-04-01

    DNA-based transposable elements are ubiquitous constituents of eukaryotic genomes. Vertebrates are, however, exceptional in that most of their DNA-based elements appear to be inactivated. The Tol1 element of the medaka fish, Oryzias latipes, is one of the few elements for which copies containing an undamaged gene have been found. Spontaneous transposition of this element in somatic cells has previously been demonstrated, but there is only indirect evidence for its germline transposition. Here, we show direct evidence of spontaneous excision in the germline. Tyrosinase is the key enzyme in melanin biosynthesis. In an albino laboratory strain of medaka fish, which is homozygous for a mutant tyrosinase gene in which a Tol1 copy is inserted, we identified de novo reversion mutations related to melanin pigmentation. The gamete-based reversion rate was as high as 0.4%. The revertant fish carried the tyrosinase gene from which the Tol1 copy had been excised. We previously reported the germline transposition of Tol2, another DNA-based element that is thought to be a recent invader of the medaka fish genome. Tol1 is an ancient resident of the genome. Our results indicate that even an old element can contribute to genetic variation in the host genome as a natural mutator.

  4. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models

    Mondon, J.A.; Howitt, J.; Tosiano, M.; Kwok, K.W.H.; Hinton, D.E.

    2011-01-01

    Highlights: → Hepatic lipidosis in fish liver is often misdiagnosed or overlooked. → Specific histological fat stains and cryostat sections are not commonly used. → Standard paraffin processing removes lipid leaving vacuoles of unknown origin. → Osmium post-fixed paraffin-embedment is a cost effective alternative. → Medaka trials show suitability for lipid visualization in tissues from egg to adult. - Abstract: Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  5. Comment: 212 [Taxonomy Icon

    Full Text Available Oryzias javanicus Oryzias javanicus Oryzias_javanicus_L.png 212.png Kiyoshi Naruse ...(National Institute for Basic Biology) licensed under CC Attribution2.1 Japan ジャワメダカ (Oryzias javanicus) インド

  6. Physiological and behavioural impacts of Pacific ciguatoxin-1 (P-CTX-1) on marine medaka (Oryzias melastigma).

    Mak, Yim Ling; Li, Jing; Liu, Chih-Ning; Cheng, Shuk Han; Lam, Paul K S; Cheng, Jinping; Chan, Leo L

    2017-01-05

    Ciguatoxins (CTXs) are natural biotoxins produced by benthic dinoflagellates of the genus Gambierdiscus, which are bioaccumulated and biotransformed along food chains in coral ecosystems. They are neurotoxins that activate voltage-gated sodium channels and disrupt ion conductance in the excitable tissues. Pacific ciguatoxin-1 (P-CTX-1) is the most prevalent and potent CTX congener present in fishes from the Pacific Ocean. In this study, P-CTX-1 was administrated to larval marine medaka (2h post-hatch) via microinjection. Exposure to P-CTX-1 at sub-ppb levels led to adverse behavioural changes, altered physiological performances and reduced survivability of the larval marine medaka as early as 24h after exposure. P-CTX-1 decreased the rate of heartbeat and locomotion of the exposed larvae, probably owing to a series of physiological processes and morphological changes such as pericardial oedema, failure of swim bladder inflation and spinal curvature. The exposed larval marine medaka also demonstrated reduced, delayed and paralyzed responses to external stimulations. This may render them more susceptible to predation. P-CTX-1 could be effectively distributed from the yolk sac to all parts of the fish body, including head and trunk, 24h after exposure. Repeated low-dose P-CTX-1 exposure resulted in larval mortality comparable to that of a single high-dose exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. How many fish in a tank? Constructing an automated fish counting system by using PTV analysis

    Abe, S.; Takagi, T.; Takehara, K.; Kimura, N.; Hiraishi, T.; Komeyama, K.; Torisawa, S.; Asaumi, S.

    2017-02-01

    Because escape from a net cage and mortality are constant problems in fish farming, health control and management of facilities are important in aquaculture. In particular, the development of an accurate fish counting system has been strongly desired for the Pacific Bluefin tuna farming industry owing to the high market value of these fish. The current fish counting method, which involves human counting, results in poor accuracy; moreover, the method is cumbersome because the aquaculture net cage is so large that fish can only be counted when they move to another net cage. Therefore, we have developed an automated fish counting system by applying particle tracking velocimetry (PTV) analysis to a shoal of swimming fish inside a net cage. In essence, we treated the swimming fish as tracer particles and estimated the number of fish by analyzing the corresponding motion vectors. The proposed fish counting system comprises two main components: image processing and motion analysis, where the image-processing component abstracts the foreground and the motion analysis component traces the individual's motion. In this study, we developed a Region Extraction and Centroid Computation (RECC) method and a Kalman filter and Chi-square (KC) test for the two main components. To evaluate the efficiency of our method, we constructed a closed system, placed an underwater video camera with a spherical curved lens at the bottom of the tank, and recorded a 360° view of a swimming school of Japanese rice fish (Oryzias latipes). Our study showed that almost all fish could be abstracted by the RECC method and the motion vectors could be calculated by the KC test. The recognition rate was approximately 90% when more than 180 individuals were observed within the frame of the video camera. These results suggest that the presented method has potential application as a fish counting system for industrial aquaculture.

  8. Final report- Links between persistent DNA damage, genome instability, and aging

    Dynan, William S. [Emory Univ., Atlanta, GA (United States)

    2016-11-30

    The goal of the project was to determine whether high linear energy transfer (LET) space radiation produces the same or different effects as low doses of terrestrial (low-LET) radiation. The work used the Japanese medaka fish (Oryzias latipes) as a vertebrate model organism that can be maintained in large numbers at low cost for lifetime studies. To determine whether simulated space radiation produced the same or different effects as low doses of low-LET radiation, medaka embryos were irradiated at doses ranging from 0.1 to 9 Gray (Gy) of high-LET charged particle radiation (1000 MeV/nucleon 56-Fe ions) or 0.1 Gy to 27 Gy of low-LET gamma-rays. To examine the effect of irradiation on potential biomarkers, the population was sampled at intervals from 8 to 28 months post-irradiation and liver tissue was subjected to histological and molecular analysis. Charged particle radiation and aging contributed synergistically to accumulation of lipid oxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in mRNA encoding the transcriptional activator PPARGC1A, which is required for mitochondrial maintenance and for defense against oxidative stress. Additionally, mitochondria had an elongated and enlarged ultrastructure. Depending on the endpoint, effects of gamma-rays in the same dose range were either lesser or not detected. Together, results indicate that a single exposure to high-LET, but not low-LET radiation, early in life, leads to increased oxidative stress throughout the normal lifespan of the individual.

  9. Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

    Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

    2016-09-01

    Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. © 2016 SETAC.

  10. Rapid and simple method for quantitative evaluation of neurocytotoxic effects of radiation on developing medaka brain

    Yasuda, Takako; Maeda, Keiko; Matsumoto, Atsuko; Maruyama, Kouichi; Ishikawa, Yuji; Yoshimoto, Masami

    2008-01-01

    We describe a novel method for rapid and quantitative evaluation of the degree of radiation-induced apoptosis in the developing brain of medaka (Oryzias latipes). Embryos at stage 28 were irradiated with 1, 2, 3.5, and 5 Gy x-ray. Living embryos were stained with a vital dye, acridine orange (AO), for 1-2 h, and whole-mount brains were examined under an epifluorescence microscope. From 7 to 10 h after irradiation with 5 Gy x-ray, we found two morphologically different types of AO-stained structures, namely, small single nuclei and rosette-shaped nuclear clusters. Electron microscopy revealed that these two distinct types of structures were single apoptotic cells with condensed nuclei and aggregates of apoptotic cells, respectively. From 10 to 30 h after irradiation, a similar AO-staining pattern was observed. The numbers of AO-stained rosette-shaped nuclear clusters and AO-stained single nuclei increased in a dose-dependent manner in the optic tectum. We used the number of AO-stained rosette-shaped nuclear clusters/optic tectum as an index of the degree of radiation-induced brain cell death at 20-24 h after irradiation. The results showed that the number of rosette-shaped nuclear clusters/optic tectum in irradiated embryos exposed to 2 Gy or higher doses was highly significant compared to the number in nonirradiated control embryos, whereas no difference was detected at 1 Gy. Thus, the threshold dose for brain cell death in medaka embryos was taken as being between 1-2 Gy, which may not be so extraordinarily large compared to those for rodents and humans. The results show that medaka embryos are useful for quantitative evaluation of developmental neurocytotoxic effects of radiation. (author)

  11. Evaluation of fish models of soluble epoxide hydrolase inhibition.

    Newman, J W; Denton, D L; Morisseau, C; Koger, C S; Wheelock, C E; Hinton, D E; Hammock, B D

    2001-01-01

    Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). We screened a set of chemicals containing these functionalities in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. Both fathead minnow and medaka sEHs were functionally similar to the tested mammalian orthologs (murine and human) with respect to substrate hydrolysis and inhibitor susceptibility. Low lethality was observed in either larval or embryonic fish exposed to diuron [N-(3,4-dichlorophenyl), N'-dimethyl urea], desmethyl diuron [N-(3,4-dichlorophenyl), N'-methyl urea], or siduron [N-(1-methylcyclohexyl), N'-phenyl urea]. Dose-dependent inhibition of sEH was a sublethal effect of substituted urea exposure with the potency of siduron diuron = diuron, differing from the observed in vitro sEH inhibition potency of siduron > desmethyl diuron > diuron. Further, siduron exposure synergized the toxicity of trans-stilbene oxide in fathead minnows. Medaka embryos exposed to diuron, desmethyl diuron, or siduron displayed dose-dependent delays in hatch, and elevated concentrations of diuron and desmethyl diuron produced developmental toxicity. The dose-dependent toxicity and in vivo sEH inhibition correlated, suggesting a potential, albeit undefined, relationship between these factors. Additionally, the observed inversion of in vitro to in vivo potency suggests that these fish models may provide tools for investigating the in vivo stability of in vitro inhibitors while screening for untoward effects. PMID:11171526

  12. Estradiol-induced promotion of hepatocarcinogenesis in medaka: Relationship of foci of cellular alteration to neoplasia

    Cooke, J.B.; Hinton, D.E. [Univ. of California, Davis, CA (United States)

    1995-12-31

    In some laboratory and field studies, female fish have higher prevalences of liver tumors than do males. The authors hypothesize gender and site-specific differences in prevalence are due to variable exposures of previously initiated fish to tumor modulating compounds. Estradiol, a growth promoter, increases incidences of hepatic tumors in carcinogen-treated rainbow trout and medaka (Oryzias latipes). Estradiol also increases incidences of hepatic foci of cellular alteration (FCA) in medaka. FCA are found in subadults of tumor-bearing feral populations. Lack of knowledge about the relationship of various phenotypes of FCA to eventual tumors, however, has prevented use of FCA as a biomarker. The authors examined fate and growth of liver FCA using a 2-step, initiation-promotion protocol. Three week old medaka were exposed to 200 ppm diethylnitrosamine (DEN) for 24 hr. and then fed 0.1 ppm 17-{beta}-estradiol (E2) continuously through sampling at weeks 4--26. Percent volume of FCA and morphometric characteristics of normal and focal hepatocytes, including numerical density and average hepatocyte volume were quantified using computer-assisted stereology. E2 increased percentage of liver occupied by DEN-initiated amphophilic, basophilic and eosinophilic FCA in both sexes. Focal parameters of young, DEN-initiated and estradiol-treated medaka were not reached until much later in fish given only DEN. Non-focal hepatocytes in estradiol-treated medaka were smaller and more numerous than in DEN-only counterparts. Morphometric analysis is quantitatively tracking the fate of specific phenotypes of FCA to determine their role in progression to cancer.

  13. p53-Dependent suppression of genome instability in germ cells

    Otozai, Shinji [Department of Otorhinolaryngology and Head and Neck Surgery, Osaka University School of Medicine, Osaka 565-0871 (Japan); Ishikawa-Fujiwara, Tomoko [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Oda, Shoji [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Kamei, Yasuhiro [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ryo, Haruko [Nomura Project, National Institute of Biomedical Innovation, Osaka 565-0085 (Japan); Sato, Ayuko [Department of Pathology, Hyogo College of Medicine, Hyogo 663-8501 (Japan); Nomura, Taisei [Nomura Project, National Institute of Biomedical Innovation, Osaka 565-0085 (Japan); Mitani, Hiroshi [Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562 (Japan); Tsujimura, Tohru [Department of Pathology, Hyogo College of Medicine, Hyogo 663-8501 (Japan); Inohara, Hidenori [Department of Otorhinolaryngology and Head and Neck Surgery, Osaka University School of Medicine, Osaka 565-0871 (Japan); Todo, Takeshi, E-mail: todo@radbio.med.osaka-u.ac.jp [Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-02-15

    Highlights: • Radiation-induced microsatellite instability (MSI) was investigated in medaka fish. • msh2{sup −/−} fish had a high frequency of spontaneous MSI. • p53{sup −/−} fish had a high frequency of radiation-induced MSI. • p53 and msh2 suppress MSI by different pathways: mismatch removal and apoptosis. - Abstract: Radiation increases mutation frequencies at tandem repeat loci. Germline mutations in γ-ray-irradiated medaka fish (Oryzias latipes) were studied, focusing on the microsatellite loci. Mismatch-repair genes suppress microsatellite mutation by directly removing altered sequences at the nucleotide level, whereas the p53 gene suppresses genetic alterations by eliminating damaged cells. The contribution of these two defense mechanisms to radiation-induced microsatellite instability was addressed. The spontaneous mutation frequency was significantly higher in msh2{sup −/−} males than in wild-type fish, whereas there was no difference in the frequency of radiation-induced mutations between msh2{sup −/−} and wild-type fish. By contrast, irradiated p53{sup −/−} fish exhibited markedly increased mutation frequencies, whereas their spontaneous mutation frequency was the same as that of wild-type fish. In the spermatogonia of the testis, radiation induced a high level of apoptosis both in wild-type and msh2{sup −/−} fish, but negligible levels in p53{sup −/−} fish. The results demonstrate that the msh2 and p53 genes protect genome integrity against spontaneous and radiation-induced mutation by two different pathways: direct removal of mismatches and elimination of damaged cells.

  14. A genetic linkage map of sole (Solea solea: a tool for evolutionary and comparative analyses of exploited (flatfishes.

    Eveline Diopere

    Full Text Available Linkage maps based on markers derived from genes are essential evolutionary tools for commercial marine fish to help identify genomic regions associated with complex traits and subject to selective forces at play during exploitation or selective breeding. Additionally, they allow the use of genomic information from other related species for which more detailed information is available. Sole (solea solea L. is a commercially important flatfish species in the North Sea, subject to overexploitation and showing evidence of fisheries-induced evolutionary changes in growth- and maturation-related traits. Sole would definitely benefit from a linkage map to better understand how evolution has shaped its genome structure. This study presents a linkage map of sole based on 423 single nucleotide polymorphisms derived from expressed sequence tags and 8 neutral microsatellite markers. The total map length is 1233.8 cM and consists of 38 linkage groups with a size varying between 0 to 92.1 cM. Being derived from expressed sequence tags allowed us to align the map with the genome of four model fish species, namely medaka (Oryzias latipes, Nile tilapia (Oreochromis niloticus, three-spined stickleback (Gasterosteus aculeatus and green spotted pufferfish (Tetraodon nigroviridis. This comparison revealed multiple conserved syntenic regions with all four species, and suggested that the linkage groups represent 21 putative sole chromosomes. The map was also compared to the linkage map of turbot (Scophthalmus maximus, another commercially important flatfish species and closely related to sole. For all putative sole chromosomes (except one a turbot homolog was detected, confirming the even higher degree of synteny between these two flatfish species.

  15. Light and electron microscopic analyses of Vasa expression in adult germ cells of the fish medaka.

    Yuan, Yongming; Li, Mingyou; Hong, Yunhan

    2014-07-15

    Germ cells of diverse animal species have a unique membrane-less organelle called germ plasm (GP). GP is usually associated with mitochondria and contains RNA binding proteins and mRNAs of germ genes such as vasa. GP has been described as the mitochondrial cloud (MC), intermitochondrial cement (IC) and chromatoid body (CB). The mechanism underlying varying GP structures has remained incompletely understood. Here we report the analysis of GP through light and electron microscopy by using Vasa as a marker in adult male germ cells of the fish medaka (Oryzias latipes). Immunofluorescence light microscopy revealed germ cell-specific Vasa expression. Vasa is the most abundant in mitotic germ cells (oogonia and spermatogonia) and reduced in meiotic germ cells. Vasa in round spermatids exist as a spherical structure reminiscent of CB. Nanogold immunoelectron microscopy revealed subcellular Vasa redistribution in male germ cells. Vasa in spermatogonia concentrates in small areas of the cytoplasm and is surrounded by mitochondria, which is reminiscent of MC. Vasa is intermixed with mitochondria to form IC in primary spermatocytes, appears as the free cement (FC) via separation from mitochondria in secondary spermatocyte and becomes condensed in CB at the caudal pole of round spermatids. During spermatid morphogenesis, Vasa redistributes and forms a second CB that is a ring-like structure surrounding the dense fiber of the flagellum in the midpiece. These structures resemble those described for GP in various species. Thus, Vasa identifies GP and adopts varying structures via dynamic reorganization at different stages of germ cell development. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Ethanol disrupts chondrification of the neurocranial cartilages in medaka embryos without affecting aldehyde dehydrogenase 1A2 (Aldh1A2) promoter methylation

    Hu, Yuhui; Willett, Kristine L.; Khan, Ikhlas A.; Scheffler, Brian E.; Dasmahapatra, Asok K.

    2009-01-01

    Medaka (Oryzias latipes) embryos at different developmental stages were exposed to ethanol for 48 h, then allowed to hatch. Teratogenic effects were evaluated in hatchlings after examining chondrocranial cartilage deformities. Ethanol disrupted cartilage development in medaka in a dose and developmental stage-specific manner. Compared to controls, the linear length of the neurocranium and other cartilages were reduced in ethanol-treated groups. Moreover, the chondrification in cartilages, specifically trabeculae and polar cartilages, were inhibited by ethanol. To understand the mechanism of ethanol teratogenesis, NAD+: NADH status during embryogenesis and the methylation pattern of Aldh1A2 promoter in whole embryos and adult tissues (brain, eye, heart and liver) were analyzed. Embryos 6 dpf had higher NAD+ than embryos 0 or 2 dpf. Ethanol (200 or 400 mM) was able to reduce NAD+ content in 2 and 6 dpf embryos. However, in both cases reductions were not significantly different from the controls. Moreover, no significant difference in either NADH content or in NAD+: NADH status of the ethanol-treated embryos, with regard to controls, was observed. The promoter of Aldh1A2 contains 31 CpG dinucleotides (-705 to +154, ATG = +1); none of which were methylated. Compared to controls, embryonic ethanol exposure (100 and 400 mM) was unable to alter Aldh1A2 promoter methylation in embryos or in the tissues of adults (breeding) developmentally exposed to ethanol (300 mM, 48 hpf). From these data we conclude that ethanol teratogenesis in medaka does not induce alteration in the methylation pattern of Aldh1A2 promoter, but does change cartilage development. PMID:19651241

  17. Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station.

    Yasuhiko Murata

    Full Text Available To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS. We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment ("Medaka Osteoclast" was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4 and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation-reduction processes (gene ontogeny term GO:0055114, and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation.

  18. p53-Dependent suppression of genome instability in germ cells

    Otozai, Shinji; Ishikawa-Fujiwara, Tomoko; Oda, Shoji; Kamei, Yasuhiro; Ryo, Haruko; Sato, Ayuko; Nomura, Taisei; Mitani, Hiroshi; Tsujimura, Tohru; Inohara, Hidenori; Todo, Takeshi

    2014-01-01

    Highlights: • Radiation-induced microsatellite instability (MSI) was investigated in medaka fish. • msh2 −/− fish had a high frequency of spontaneous MSI. • p53 −/− fish had a high frequency of radiation-induced MSI. • p53 and msh2 suppress MSI by different pathways: mismatch removal and apoptosis. - Abstract: Radiation increases mutation frequencies at tandem repeat loci. Germline mutations in γ-ray-irradiated medaka fish (Oryzias latipes) were studied, focusing on the microsatellite loci. Mismatch-repair genes suppress microsatellite mutation by directly removing altered sequences at the nucleotide level, whereas the p53 gene suppresses genetic alterations by eliminating damaged cells. The contribution of these two defense mechanisms to radiation-induced microsatellite instability was addressed. The spontaneous mutation frequency was significantly higher in msh2 −/− males than in wild-type fish, whereas there was no difference in the frequency of radiation-induced mutations between msh2 −/− and wild-type fish. By contrast, irradiated p53 −/− fish exhibited markedly increased mutation frequencies, whereas their spontaneous mutation frequency was the same as that of wild-type fish. In the spermatogonia of the testis, radiation induced a high level of apoptosis both in wild-type and msh2 −/− fish, but negligible levels in p53 −/− fish. The results demonstrate that the msh2 and p53 genes protect genome integrity against spontaneous and radiation-induced mutation by two different pathways: direct removal of mismatches and elimination of damaged cells

  19. Development of space-fertilized eggs and formation of primordial germ cells in the embryos of medaka fish

    Ijiri, K.

    In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly `space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

  20. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    Shirakashi, Ryo, E-mail: aa21150@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); Mischke, Miriam [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fischer, Peter [Physiologische Chemie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Memmel, Simon [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Krohne, Georg [Abteilung fuer Elektronenmikroskopie, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany); Fuhr, Guenter R. [Lehrstuhl fuer Biotechnologie und Medizintechnik, Universitaet des Saarlandes, Saarbruecken (Germany); Zimmermann, Heiko [Lehrstuhl fuer Molekulare und Zellulaere Biotechnologie, Universitaet des Saarlandes, Saarbruecken (Germany); Sukhorukov, Vladimir L., E-mail: sukhorukov@biozentrum.uni-wuerzburg.de [Lehrstuhl fuer Biotechnologie und Biophysik, Biozentrum, Universitaet Wuerzburg, Wuerzburg (Germany)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.

  1. Evolutionary growth process of highly conserved sequences in vertebrate genomes.

    Ishibashi, Minaka; Noda, Akiko Ogura; Sakate, Ryuichi; Imanishi, Tadashi

    2012-08-01

    Genome sequence comparison between evolutionarily distant species revealed ultraconserved elements (UCEs) among mammals under strong purifying selection. Most of them were also conserved among vertebrates. Because they tend to be located in the flanking regions of developmental genes, they would have fundamental roles in creating vertebrate body plans. However, the evolutionary origin and selection mechanism of these UCEs remain unclear. Here we report that UCEs arose in primitive vertebrates, and gradually grew in vertebrate evolution. We searched for UCEs in two teleost fishes, Tetraodon nigroviridis and Oryzias latipes, and found 554 UCEs with 100% identity over 100 bps. Comparison of teleost and mammalian UCEs revealed 43 pairs of common, jawed-vertebrate UCEs (jUCE) with high sequence identities, ranging from 83.1% to 99.2%. Ten of them retain lower similarities to the Petromyzon marinus genome, and the substitution rates of four non-exonic jUCEs were reduced after the teleost-mammal divergence, suggesting that robust conservation had been acquired in the jawed vertebrate lineage. Our results indicate that prototypical UCEs originated before the divergence of jawed and jawless vertebrates and have been frozen as perfect conserved sequences in the jawed vertebrate lineage. In addition, our comparative sequence analyses of UCEs and neighboring regions resulted in a discovery of lineage-specific conserved sequences. They were added progressively to prototypical UCEs, suggesting step-wise acquisition of novel regulatory roles. Our results indicate that conserved non-coding elements (CNEs) consist of blocks with distinct evolutionary history, each having been frozen since different evolutionary era along the vertebrate lineage. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Myosin II activity is required for functional leading-edge cells and closure of epidermal sheets in fish skin ex vivo.

    Morita, Toshiyuki; Tsuchiya, Akiko; Sugimoto, Masazumi

    2011-09-01

    Re-epithelialization in skin wound healing is a process in which epidermal sheets grow and close the wound. Although the actin-myosin system is thought to have a pivotal role in re-epithelialization, its role is not clear. In fish skin, re-epithelialization occurs around 500 μm/h and is 50 times faster than in mammalian skin. We had previously reported that leading-edge cells of the epidermal outgrowth have both polarized large lamellipodia and "purse string"-like actin filament cables in the scale-skin culture system of medaka fish, Oryzias latipes (Cell Tissue Res, 2007). The actin purse-string (APS) is a supracellular contractile machinery in which adherens junctions (AJs) link intracellular myosin II-including actin cables between neighboring cells. In this study, we developed a modified "face-to-face" scale-skin culture system as an ex vivo model to study epidermal wound healing, and examined the role of the actin-myosin system in the rapid re-epithelialization using a myosin II ATPase inhibitor, blebbistatin. A low level of blebbistatin suppressed the formation of APS and induced the dissociation of keratocytes from the leading edge without attenuating the growth of the epidermal sheet or the migration rate of solitary keratocytes. AJs in the superficial layer showed no obvious changes elicited by blebbistatin. However, two epidermal sheets without APSs did not make a closure with each other, which was confirmed by inhibiting the connecting AJs between the superficial layers. These results suggest that myosin II activity is required for functional leading-edge cells and for epidermal closure.

  3. The medaka novel immune-type receptor (NITR gene clusters reveal an extraordinary degree of divergence in variable domains

    Litman Gary W

    2008-06-01

    Full Text Available Abstract Background Novel immune-type receptor (NITR genes are members of diversified multigene families that are found in bony fish and encode type I transmembrane proteins containing one or two extracellular immunoglobulin (Ig domains. The majority of NITRs can be classified as inhibitory receptors that possess cytoplasmic immunoreceptor tyrosine-based inhibition motifs (ITIMs. A much smaller number of NITRs can be classified as activating receptors by the lack of cytoplasmic ITIMs and presence of a positively charged residue within their transmembrane domain, which permits partnering with an activating adaptor protein. Results Forty-four NITR genes in medaka (Oryzias latipes are located in three gene clusters on chromosomes 10, 18 and 21 and can be organized into 24 families including inhibitory and activating forms. The particularly large dataset acquired in medaka makes direct comparison possible to another complete dataset acquired in zebrafish in which NITRs are localized in two clusters on different chromosomes. The two largest medaka NITR gene clusters share conserved synteny with the two zebrafish NITR gene clusters. Shared synteny between NITRs and CD8A/CD8B is limited but consistent with a potential common ancestry. Conclusion Comprehensive phylogenetic analyses between the complete datasets of NITRs from medaka and zebrafish indicate multiple species-specific expansions of different families of NITRs. The patterns of sequence variation among gene family members are consistent with recent birth-and-death events. Similar effects have been observed with mammalian immunoglobulin (Ig, T cell antigen receptor (TCR and killer cell immunoglobulin-like receptor (KIR genes. NITRs likely diverged along an independent pathway from that of the somatically rearranging antigen binding receptors but have undergone parallel evolution of V family diversity.

  4. A comprehensive study of the toxicity of natural multi-contaminated sediments: New insights brought by the use of a combined approach using the medaka embryo-larval assay and physico-chemical analyses.

    Barjhoux, Iris; Clérandeau, Christelle; Menach, Karyn Le; Anschutz, Pierre; Gonzalez, Patrice; Budzinski, Hélène; Morin, Bénédicte; Baudrimont, Magalie; Cachot, Jérôme

    2017-08-01

    Sediment compartment is a long term sink for pollutants and a secondary source of contamination for aquatic species. The abiotic factors controlling the bioavailability and thus the toxicity of complex mixtures of pollutants accumulated in sediments are poorly documented. To highlight the different factors influencing sediment toxicity, we identified and analyzed the physico-chemical properties, micro-pollutant contents, and toxicity level of six contrasted sediments in the Lot-Garonne continuum. Sediment toxicity was evaluated using the recently described Japanese medaka (Oryzias latipes) embryo-larval assay with direct exposure to whole sediment (MELAc). Multiple toxicity endpoints including embryotoxicity, developmental defects and DNA damage were analyzed in exposed embryos. Chemical analyses revealed significant variations in the nature and contamination profile of sediments, mainly impacted by metallic trace elements and, unexpectedly, polycyclic aromatic hydrocarbons. Exposure to sediments induced different toxic impacts on medaka early life stages when compared with the reference site. Principal component analysis showed that the toxic responses following exposure to sediments from the Lot River and its tributary were associated with micro-pollutant contamination: biometric measurements, hatching success, genotoxicity, craniofacial deformities and yolk sac malabsorption were specifically correlated to metallic and organic contaminants. Conversely, the main biological responses following exposure to the Garonne River sediments were more likely related to their physico-chemical properties than to their contamination level. Time to hatch, cardiovascular injuries and spinal deformities were correlated to organic matter content, fine particles and dissolved oxygen levels. These results emphasize the necessity of combining physico-chemical analysis of sediment with toxicity assessment to accurately evaluate the environmental risks associated with sediment

  5. Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment

    Rochman, Chelsea M.; Kurobe, Tomofumi; Flores, Ida; Teh, Swee J.

    2014-01-01

    Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (< 1 mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3 months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research. - Highlights: • We saw down-regulation of Chg H in males exposed to marine plastic. • We saw down-regulation of Vtg I, Chg H and ERα in females exposed to plastic. • We saw abnormal proliferation of germ cells in a male exposed to marine plastic. • Our results suggest that the ingestion of plastic may alter endocrine system function

  6. TALENs-mediated gene disruption of myostatin produces a larger phenotype of medaka with an apparently compromised immune system.

    Chiang, Yi-An; Kinoshita, Masato; Maekawa, Shun; Kulkarni, Amod; Lo, Chu-Fang; Yoshiura, Yasutoshi; Wang, Han-Ching; Aoki, Takashi

    2016-01-01

    Although myostatin, a suppressor of skeletal muscle development and growth, has been well studied in mammals, its function in fish remains unclear. In this study, we used a popular genome editing tool with high efficiency and target specificity (TALENs; transcription activator-like effector nucleases) to mutate the genome sequence of myostatin (MSTN) in medaka (Oryzias latipes). After the TALEN pair targeting OlMyostatin was injected into fertilized medaka eggs, mutant G0 fish carrying different TALENs-induced frameshifts in the OlMSTN coding sequence were mated together in order to transmit the mutant sequences to the F1 generation. Two F1 mutants with frameshifted myostatin alleles were then mated to produce the F2 generation, and these F2 OlMSTN null (MSTN(-/-)) medaka were evaluated for growth performance. The F2 fish showed significantly increased body length and weight compared to the wild type fish at the juvenile and post-juvenile stages. At the post-juvenile stage, the average body weight of the MSTN(-/-) medaka was ∼25% greater than the wild type. However, we also found that when the F3 generation were challenged with red spotted grouper nervous necrosis virus (RGNNV), the expression levels of the interferon-stimulated genes were lower than in the wild type, and the virus copy number was maintained at a high level. We therefore conclude that although the MSTN(-/-) medaka had a larger phenotype, their immune system appeared to be at least partially suppressed or undeveloped. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Conserved regulatory modules in the Sox9 testis-specific enhancer predict roles for SOX, TCF/LEF, Forkhead, DMRT, and GATA proteins in vertebrate sex determination.

    Bagheri-Fam, Stefan; Sinclair, Andrew H; Koopman, Peter; Harley, Vincent R

    2010-03-01

    While the primary sex determining switch varies between vertebrate species, a key downstream event in testicular development, namely the male-specific up-regulation of Sox9, is conserved. To date, only two sex determining switch genes have been identified, Sry in mammals and the Dmrt1-related gene Dmy (Dmrt1bY) in the medaka fish Oryzias latipes. In mice, Sox9 expression is evidently up-regulated by SRY and maintained by SOX9 both of which directly activate the core 1.3 kb testis-specific enhancer of Sox9 (TESCO). How Sox9 expression is up-regulated and maintained in species without Sry (i.e. non-mammalian species) is not understood. In this study, we have undertaken an in-depth comparative genomics approach and show that TESCO contains an evolutionarily conserved region (ECR) of 180 bp which is present in marsupials, monotremes, birds, reptiles and amphibians. The ECR contains highly conserved modules that predict regulatory roles for SOX, TCF/LEF, Forkhead, DMRT, and GATA proteins in vertebrate sex determination/differentiation. Our data suggest that tetrapods share common aspects of Sox9 regulation in the testis, despite having different sex determining switch mechanisms. They also suggest that Sox9 autoregulation is an ancient mechanism shared by all tetrapods, raising the possibility that in mammals, SRY evolved by mimicking this regulation. The validation of ECR regulatory sequences conserved from human to frogs will provide new insights into vertebrate sex determination. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Nanosecond pulsed electric field incorporation technique to predict molecular mechanisms of teratogenicity and developmental toxicity of estradiol-17β on medaka embryos.

    Yamaguchi, Akemi; Ishibashi, Hiroshi; Kono, Susumu; Iida, Midori; Uchida, Masaya; Arizono, Koji; Tominaga, Nobuaki

    2018-05-01

    Herein, we propose using a nanosecond pulsed electric field (nsPEF) technique to assess teratogenicity and embryonic developmental toxicity of estradiol-17β (E 2 ) and predict the molecular mechanisms of teratogenicity and embryonic developmental defects caused by E 2 on medaka (Oryzias latipes). The 5 hour post-fertilization embryos were exposed to co-treatment with 10 μm E 2 and nsPEF for 2 hours and then continuously cultured under non-E 2 and nsPEF conditions until hatching. Results documented that the time to hatching of embryos was significantly delayed in comparison to the control group and that typical abnormal embryo development, such as the delay of blood vessel formation, was observed. For DNA microarray analysis, 6 day post-fertilization embryos that had been continuously cultured under the non-E 2 and nsPEF condition after 2 hour co-treatments were used. DNA microarray analysis identified 542 upregulated genes and one downregulated gene in the 6 day post-fertilization embryos. Furthermore, bioinformatic analyses using differentially expressed genes revealed that E 2 exposure affected various gene ontology terms, such as response to hormone stimulus. The network analysis also documented that the estrogen receptor α in the mitogen-activated protein kinase signaling pathway may be involved in regulating several transcription factors, such as FOX, AKT1 and epidermal growth factor receptor. These results suggest that our nsPEF technique is a powerful tool for assessing teratogenicity and embryonic developmental toxicity of E 2 and predict their molecular mechanisms in medaka embryos. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment

    Rochman, Chelsea M., E-mail: cmrochman@ucdavis.edu; Kurobe, Tomofumi; Flores, Ida; Teh, Swee J.

    2014-09-15

    Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (< 1 mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3 months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research. - Highlights: • We saw down-regulation of Chg H in males exposed to marine plastic. • We saw down-regulation of Vtg I, Chg H and ERα in females exposed to plastic. • We saw abnormal proliferation of germ cells in a male exposed to marine plastic. • Our results suggest that the ingestion of plastic may alter endocrine system function.

  10. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

    Lin, Chun-Hung [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China); Chou, Pei-Hsin [Department of Environmental Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chen, Pei-Jen, E-mail: chenpj@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan (China)

    2014-07-30

    Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

  11. Extended fish short term reproduction assays with the fathead minnow and Japanese medaka: No evidence of impaired fecundity from exposure to atrazine.

    Brain, Richard A; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Wolf, Jeffrey C; Hanson, Mark L

    2018-08-01

    Short-term reproduction assays were conducted with fathead minnow (Pimephales promelas) and Japanese medaka (Oryzias latipes) to evaluate responses from atrazine exposure at environmentally relevant concentrations and above. Breeding groups of fish with multiple males and females were exposed to atrazine under flow-through conditions. Fathead minnows were exposed to mean measured concentrations of 1.0, 10, 26, 52, and 105 μg atrazine/L for 28 days. Medaka were exposed to mean measured concentrations of 9.4, 48, 74, 97, and 244 μg atrazine/L for 28 or 29 days. Fish were evaluated for survival, fecundity, fertility, total length, wet weight, secondary sex characteristics, gonadosomatic index (GSI) (P. promelas only), plasma or hepatic vitellogenin (VTG), and histopathology of gonads. General observations of health and behaviour were also conducted. There were no statistically significant effects (i.e., p < 0.05) of atrazine on survival, size, reproduction, behaviour, GSI, VTG, or secondary sex characteristics in either species at any exposure level. In fathead minnows, there were no histopathological findings associated with atrazine exposure in male fish, but there was an increased proportion of Stage 4.0 ovaries accompanied by an increase in proportion of Grade 3 post-ovulatory follicles in females of the 105 μg/L treatment group. Without a concomitant increase in oocyte atresia, neither of these findings are considered adverse for the health of the fish. In medaka, there were no significant effects of atrazine exposure on histopathology in either sex. These data support current weight-of-evidence assessments that atrazine does not cause direct adverse effects on fish reproduction at environmentally realistic concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Environmentally relevant concentrations of di(2-ethylhexyl)phthalate exposure alter larval growth and locomotion in medaka fish via multiple pathways.

    Yang, Wen-Kai; Chiang, Li-Fen; Tan, Shi-Wei; Chen, Pei-Jen

    2018-06-01

    Di(2-ethylhexyl)phthalate (DEHP) is a commonly used plasticizer, with evidence of ubiquitous human exposure and widespread occurrence in the aquatic environment. It is an emerging environmental pollutant with regulatory priority; however, most studies have focused on the toxicity of DEHP related to endocrine disruption and reproduction in mammals. The ecotoxicological impact of phthalates (e.g., DEHP) on early life stages of fish under environmentally relevant concentrations of chronic exposure remains unclear. In this study, 7-day post-hatching fry of medaka fish (Oryzias latipes) underwent 21-day continuous exposure to DEHP solutions at 20, 100 and 200 μg/L to assess the effects on fish development and locomotion and related toxic mechanisms. Larval mortality was low with DEHP (20-200 μg/L) within 21 days, but such exposure significantly reduced fish body weight and length and altered swimming behavior. At 21 days, DEHP exposure resulted in specific patterns of larval locomotion (e.g., increased maximum velocity and absolute turn angle) and dose-dependently increased the mRNA expression of acetylcholinesterase (ache) but did not alter AChE activity. Transcriptional expression of antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase and peroxisome proliferation-activated receptor and retinoid X receptor genes was significantly suppressed with 21-day DEHP exposure (20-200 μg/L), with marginal alteration in reactive oxygen species levels and antioxidant activities within the dosing period. As well, DEHP altered the mRNA expression of p53-regulated apoptosis pathways, such as upregulated p53, p21 and bcl-2 and downregulated caspase-3 expression, with increased enzymatic activity of caspase-3 in larvae. Our results suggest that toxic mechanisms of waterborne DEHP altered fish growth and locomotion likely via a combined effect of oxidative stress, neurotoxicity and apoptosis pathways. Copyright © 2018

  13. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    Shirakashi, Ryo; Mischke, Miriam; Fischer, Peter; Memmel, Simon; Krohne, Georg; Fuhr, Günter R.; Zimmermann, Heiko; Sukhorukov, Vladimir L.

    2012-01-01

    Highlights: ► Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. ► The three-shell dielectric model matches the rotation spectra of medaka eggs. ► The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz–MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos’ viability/conditions in basic research and industrial aquaculture.

  14. Highly efficient generation of knock-in transgenic medaka by CRISPR/Cas9-mediated genome engineering.

    Watakabe, Ikuko; Hashimoto, Hisashi; Kimura, Yukiko; Yokoi, Saori; Naruse, Kiyoshi; Higashijima, Shin-Ichi

    2018-01-01

    Medaka ( Oryzias latipes ) is a popular animal model used in vertebrate genetic analysis. Recently, an efficient (~ 30%) knock-in system via non-homologous end joining (NHEJ) was established in zebrafish using the CRISPR/Cas9 system. If the same technique were applicable in medaka, it would greatly expand the usefulness of this model organism. The question of the applicability of CRISPR/Cas9 in medaka, however, has yet to be addressed. We report the highly efficient generation of knock-in transgenic medaka via non-homologous end joining (NHEJ). Donor plasmid containing a heat-shock promoter and a reporter gene was co-injected with a short guide RNA (sgRNA) targeted for genome digestion, an sgRNA targeted for donor plasmid digestion, and Cas9 mRNA. Broad transgene expression in the expression domain of a target gene was observed in approximately 25% of injected embryos. By raising these animals, we established stable knock-in transgenic fish with several different constructs for five genetic loci, obtaining transgenic founders at efficiencies of > 50% for all five loci. Further, we show that the method is useful for obtaining mutant alleles. In the experiments where transgene integrations were targeted between the transcription start site and the initiation methionine, the resultant transgenic fish became mutant alleles. With its simplicity, design flexibility, and high efficiency, we propose that CRISPR/Cas9-mediated knock-in via NHEJ will become a standard method for the generation of transgenic and mutant medaka.

  15. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish

    Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

    2014-01-01

    Highlights: • We assess ecotoxicological impact of azole fungicides in the aquatic environment. • Carcinogenic and non-carcinogenic azoles show different CYP activities in medaka. • We compare azole-induced CYP expression and carcinogenesis between fish and rodents. • Liver CYP-enzyme induction is a key event in conazole-induced tumorigenesis. • We suggest toxicity evaluation methods for azole fungicides using medaka fish. - Abstract: Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish

  16. Tritium behavior in an aquatic ecosystem

    Komatsu, K.

    1982-01-01

    Tritium behavior in aquatic organisms through a model food chain was investigated. In this model food chain, tritium in water reaches bacteria or Japanese killifish via diatoms and brine shrimps. Tritium accumulation in these organisms as organic bound form was expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms: Chaetoceros gracilis, 0.2 in bacteria: Escherichia coli, 0.5 in brine shrimps: Artemia salina, and 0.32 in Japanese killifish: Oryzias latipes under the growing condition in which tritium accumulation was due to tritium in tritiated water and not tritiated foods. Brine shrimps and Japanese killifish were grown from larve to adult in tritiated sea water and were fed on tritiated foods (model food chain). Their R values were 0.70 and 0.67, respectively. Bacteria, which grew in tritiated water by adding the hydrolysate of tritiated brine shrimps, showed a maximum R value at 0.32. The R values of each organ of Japanese killifish and of DNA and the nucleotides purified from brine shrimps growing in tritiated water with or without tritiated food were measured to estimate the tritium distribution in the body or various molecules of the organisms. These results did not indicate concentration of tritium in specific organs or compounds. The changes of specific activity of tritium in these organisms were measured when they were transferred to non-tritiated water. These retention of tritium was not only different among the tissues but also depended on whether or not the organisms were reared with tritiated foods. (author)

  17. Radioecological studies of {sup 137}Cs in limnological ecosystems. Accumulation and excretion of {sup 137}Cs in goldfish, Carassius auratus auratus, from diets

    Miyake, Sadaaki; Motegi, Misako; Oosawa, Takashi; Nakazawa, Kiyoaki [Saitama Inst. of Public Health, Urawa (Japan); Ogata, Hiromitsu; Izumo, Yoshiro; Nakamura, Fumio

    1996-06-01

    Accumulation and excretion Of {sup 137}Cs in goldfish, Carassius auratus auratus, from radioactive diets (killifish, Oryzias latipes, meats accumulated {sup 137}Cs in the radioactive freshwater) or control diets (killifish meats mixed {sup 137}CsCl) were investigated in order to elucidate the accumulation mechanism of the radionuclide in natural living fishes. The accumulation of {sup 137}Cs, expressed in concentration ratio, in whole body of the fish showed a increasing tendency in proportion to the rearing time. On the other hand, the excretion of {sup 137}Cs, expressed in retention rate, in whole body rearing by administration of non-radioactive commercial diets after the accumulation above for 7 days, demonstrated a rapid decreasing at first few days, and followed a gradual decreasing tendency (the biological half lives were about 1.5 days and 52 days, respectively). As for the tissues and organs, higher accumulation and higher excretion were found in the viscera than those in the muscle. It is so suggested that the metabolic turnover rate of this radionuclide for the viscera is more rapid than that for the muscle. From the experimental results, it was confirmed that the relative contribution by ingestion of the radioactive diets in the accumulation of {sup 137}Cs in natural environmental fish was comparatively higher in comparison with uptake of the radionuclide in the radioactive freshwater. With regard to the difference between the radioactive diets and the control diets, the accumulation of {sup 137}Cs in whole body of the fish from the radioactive diets was less than that from the control diets to rearing 5 days, but afterward was not different. The difference of the accumulation between these diets will be attributable to that of the metabolic turnover between these diets. (author)

  18. Exposure to a PBDE/OH-BDE mixture alters juvenile zebrafish (Danio rerio) development.

    Macaulay, Laura J; Chernick, Melissa; Chen, Albert; Hinton, David E; Bailey, Jordan M; Kullman, Seth W; Levin, Edward D; Stapleton, Heather M

    2017-01-01

    Polybrominated diphenyl ethers (PBDEs) and their metabolites (e.g., hydroxylated BDEs [OH-BDEs]) are contaminants frequently detected together in human tissues and are structurally similar to thyroid hormones. Thyroid hormones partially mediate metamorphic transitions between life stages in zebrafish, making this a critical developmental window that may be vulnerable to chemicals disrupting thyroid signaling. In the present study, zebrafish were exposed to 6-OH-BDE-47 (30 nM; 15 μg/L) alone, or to a low-dose (30 μg/L) or high-dose (600 μg/L) mixture of PentaBDEs, 6-OH-BDE-47 (0.5-6 μg/L), and 2,4,6-tribromophenol (5-100 μg/L) during juvenile development (9-23 d postfertilization) and evaluated for developmental endpoints mediated by thyroid hormone signaling. Fish were sampled at 3 time points and examined for developmental and skeletal morphology, apical thyroid and skeletal gene markers, and modifications in swimming behavior (as adults). Exposure to the high-dose mixture resulted in >85% mortality within 1 wk of exposure, despite being below reported acute toxicity thresholds for individual congeners. The low-dose mixture and 6-OH-BDE-47 groups exhibited reductions in body length and delayed maturation, specifically relating to swim bladder, fin, and pigmentation development. Reduced skeletal ossification was also observed in 6-OH-BDE-47-treated fish. Assessment of thyroid and osteochondral gene regulatory networks demonstrated significantly increased expression of genes that regulate skeletal development and thyroid hormones. Overall, these results indicate that exposures to PBDE/OH-BDE mixtures adversely impact zebrafish maturation during metamorphosis. Environ Toxicol Chem 2017;36:36-48. © 2016 SETAC. © 2016 SETAC.

  19. Bipolar Cell-Photoreceptor Connectivity in the Zebrafish (Danio rerio) Retina

    Li, Yong N.; Tsujimura, Taro; Kawamura, Shoji; Dowling, John E.

    2013-01-01

    Bipolar cells convey luminance, spatial and color information from photoreceptors to amacrine and ganglion cells. We studied the photoreceptor connectivity of 321 bipolar cells in the adult zebrafish retina. 1,1'-Dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) was inserted into whole-mounted transgenic zebrafish retinas to label bipolar cells. The photoreceptors that connect to these DiI-labeled cells were identified by transgenic fluorescence or their positions relative to the fluorescent cones, as cones are arranged in a highly-ordered mosaic: rows of alternating blue- (B) and ultraviolet-sensitive (UV) single cones alternate with rows of red- (R) and green-sensitive (G) double cones. Rod terminals intersperse among cone terminals. As many as 18 connectivity subtypes were observed, 9 of which – G, GBUV, RG, RGB, RGBUV, RGRod, RGBRod, RGBUVRod and RRod bipolar cells – accounted for 96% of the population. Based on their axon terminal stratification, these bipolar cells could be further sub-divided into ON, OFF, and ON-OFF cells. The dendritic spread size, soma depth and size, and photoreceptor connections of the 308 bipolar cells within the 9 common connectivity subtypes were determined, and their dendritic tree morphologies and axonal stratification patterns compared. We found that bipolar cells with the same axonal stratification patterns could have heterogeneous photoreceptor connectivity whereas bipolar cells with the same dendritic tree morphology usually had the same photoreceptor connectivity, although their axons might stratify on different levels. PMID:22907678

  20. Evaluation of 5 Cleaning and Disinfection Methods for Nets Used to Collect Zebrafish (Danio rerio)

    Collymore, Chereen; Porelli, Gina; Lieggi, Christine; Lipman, Neil S

    2014-01-01

    Few standardized methods of cleaning and disinfecting equipment in zebrafish facilities have been published, even though the effectiveness of these procedures is vital to preventing the transmission of pathogenic organisms. Four chemical disinfectants and rinsing with municipal tap water were evaluated for their ability to disinfect nets used to capture zebrafish. The disinfectants included benzalkonium chloride+methylene blue, sodium hypochlorite, chlorine dioxide, and potassium peroxymonosu...

  1. Binary mixture of DDT and Arochlor1254: effects on sperm release by Danio rerio.

    Njiwa, Jules Richard Kemadjou; Müller, Paul; Klein, Roland

    2004-06-01

    A long-term toxicity test with zebrafish was carried out with different concentrations of DDT, Arochlor1254 (A54), and their 1:1 mixture under flow-through conditions. By collecting and counting the number of sperm released during separate mating events we observed that gametes are released asynchronously. Sperms are released in the form of sperm trails laid on the nest surface; subsequently active spermatozoa leave the trails and move in the water for several minutes. Sperm trails consist of bands of viscous material in which sperm are embedded. The water samples for the estimation of sperm presence were collected gradually within 180 min after 24 h, 2 weeks, 1 month, and 2 months of exposure. It was established that the reductions in count, activity of sperm, and average life span of sperm trails were significant (Psperm release and activity as well as the life span of their trails.

  2. Swim-training changes the spatio-temporal dynamics of skeletogenesis in zebrafish larvae (Danio rerio.

    Ansa W Fiaz

    Full Text Available Fish larvae experience many environmental challenges during development such as variation in water velocity, food availability and predation. The rapid development of structures involved in feeding, respiration and swimming increases the chance of survival. It has been hypothesized that mechanical loading induced by muscle forces plays a role in prioritizing the development of these structures. Mechanical loading by muscle forces has been shown to affect larval and embryonic bone development in vertebrates, but these investigations were limited to the appendicular skeleton. To explore the role of mechanical load during chondrogenesis and osteogenesis of the cranial, axial and appendicular skeleton, we subjected zebrafish larvae to swim-training, which increases physical exercise levels and presumably also mechanical loads, from 5 until 14 days post fertilization. Here we show that an increased swimming activity accelerated growth, chondrogenesis and osteogenesis during larval development in zebrafish. Interestingly, swim-training accelerated both perichondral and intramembranous ossification. Furthermore, swim-training prioritized the formation of cartilage and bone structures in the head and tail region as well as the formation of elements in the anal and dorsal fins. This suggests that an increased swimming activity prioritized the development of structures which play an important role in swimming and thereby increasing the chance of survival in an environment where water velocity increases. Our study is the first to show that already during early zebrafish larval development, skeletal tissue in the cranial, axial and appendicular skeleton is competent to respond to swim-training due to increased water velocities. It demonstrates that changes in water flow conditions can result into significant spatio-temporal changes in skeletogenesis.

  3. Effects of copper oxide nanoparticles and copper ions to zebrafish (Danio rerio) cells, embryos and fry

    Thit, Amalie; Skjolding, Lars Michael; Selck, Henriette

    2017-01-01

    The use of engineered metal nanoparticles (NPs) is continuously increasing and so is the need for information regarding their toxicity. This study compares the toxicity of CuO NPs with ionic Cu in three zebrafish model systems; zebrafish hepatoma cell line (ZFL), fish embryo toxicity test (FET) a...

  4. Intrinsic and extrinsic innervation of the heart in zebrafish (Danio rerio).

    Stoyek, Matthew R; Croll, Roger P; Smith, Frank M

    2015-08-01

    In the vertebrate heart the intracardiac nervous system is the final common pathway for autonomic control of cardiac output, but the neuroanatomy of this system is not well understood. In this study we investigated the innervation of the heart in a model vertebrate, the zebrafish. We used antibodies against acetylated tubulin, human neuronal protein C/D, choline acetyltransferase, tyrosine hydroxylase, neuronal nitric oxide synthase, and vasoactive intestinal polypeptide to visualize neural elements and their neurotransmitter content. Most neurons were located at the venous pole in a plexus around the sinoatrial valve; mean total number of cells was 197 ± 23, and 92% were choline acetyltransferase positive, implying a cholinergic role. The plexus contained cholinergic, adrenergic, and nitrergic axons and vasoactive intestinal polypeptide-positive terminals, some innervating somata. Putative pacemaker cells near the plexus showed immunoreactivity for hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) and the transcription factor Islet-1 (Isl1). The neurotracer neurobiotin showed that extrinsic axons from the left and right vagosympathetic trunks innervated the sinoatrial plexus proximal to their entry into the heart; some extrinsic axons from each trunk also projected into the medial dorsal plexus region. Extrinsic axons also innervated the atrial and ventricular walls. An extracardiac nerve trunk innervated the bulbus arteriosus and entered the arterial pole of the heart to innervate the proximal ventricle. We have shown that the intracardiac nervous system in the zebrafish is anatomically and neurochemically complex, providing a substrate for autonomic control of cardiac effectors in all chambers. © 2015 Wiley Periodicals, Inc.

  5. Conditioned place avoidance of zebrafish (Danio rerio to three chemicals used for euthanasia and anaesthesia.

    Devina Wong

    Full Text Available Zebrafish are becoming one of the most used vertebrates in developmental and biomedical research. Fish are commonly killed at the end of an experiment with an overdose of tricaine methanesulfonate (TMS, also known as MS-222, but to date little research has assessed if exposure to this or other agents qualifies as euthanasia (i.e. a "good death". Alternative agents include metomidate hydrochloride and clove oil. We use a conditioned place avoidance paradigm to compare aversion to TMS, clove oil, and metomidate hydrochloride. Zebrafish (n = 51 were exposed to the different anaesthetics in the initially preferred side of a light/dark box. After exposure to TMS zebrafish spent less time in their previously preferred side; aversion was less pronounced following exposure to metomidate hydrochloride and clove oil. Nine of 17 fish exposed to TMS chose not to re-enter the previously preferred side, versus 2 of 18 and 3 of 16 refusals for metomidate hydrochloride and clove oil, respectively. We conclude that metomidate hydrochloride and clove oil are less aversive than TMS and that these agents be used as humane alternatives to TMS for killing zebrafish.

  6. Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

    Alexandra Vaccaro

    Full Text Available The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C or FUS (S57Δ or R521H that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress.

  7. Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

    Vaccaro, Alexandra; Patten, Shunmoogum A; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J Alex

    2012-01-01

    The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress.

  8. The role of zebrafish (Danio rerio in dissecting the genetics and neural circuits of executive function

    Matthew O Parker

    2013-04-01

    Full Text Available Zebrafish have great potential to contribute to our understanding of behavioural genetics and thus to contribute to our understanding of the aetiology of psychiatric disease. However, progress is dependent upon the rate at which behavioural assays addressing complex behavioural phenotypes are designed, reported and validated. Here we critically review existing behavioural assays with particular focus on the use of adult zebrafish to explore executive processes and phenotypes associated with human psychiatric disease. We outline the case for using zebrafish as models to study impulse control and attention, discussing the validity of applying extant rodent assays to zebrafish and evidence for the conservation of relevant neural circuits.

  9. Operant models of relapse in zebrafish (Danio rerio): Resurgence, renewal, and reinstatement.

    Kuroda, Toshikazu; Mizutani, Yuto; Cançado, Carlos R X; Podlesnik, Christopher A

    2017-09-29

    Zebrafish are a widely used animal model in biomedical research, as an alternative to mammals, for having features such as a fully sequenced genome, high fecundity, and low-cost maintenance, but behavioral research with these fish remains scarce. The present study investigated whether zebrafish could be a new animal model for studies on the relapse of behavior (e.g., addiction and overeating) after the behavior has been extinguished. Specifically, we examined whether zebrafish would show three different types of relapse commonly studied with other species: resurgence, renewal, and reinstatement. For resurgence, a target response (i.e., approaching a sensor) was established by presenting a reinforcer (i.e., shrimp eggs) contingent upon the response in Phase 1; the target response was extinguished while introducing reinforcement for an alternative response in Phase 2; neither response produced the reinforcer in Phase 3. For renewal, a target response was established under Context A in Phase 1 and was extinguished under Context B in Phase 2; the fish were placed back in Context A in Phase 3, where extinction remained in effect. For reinstatement, a target response was established in Phase 1 and was extinguished in Phase 2; the reinforcer was presented independently of responding in Phase 3. Each type of relapse occurred in Phase 3. These results replicate and extend previous findings on relapse to a new species and suggest that zebrafish can be a useful animal model for studying the interactions of biological and environmental factors that lead to relapse. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The French press: a repeatable and high-throughput approach to exercising zebrafish (Danio rerio).

    Usui, Takuji; Noble, Daniel W A; O'Dea, Rose E; Fangmeier, Melissa L; Lagisz, Malgorzata; Hesselson, Daniel; Nakagawa, Shinichi

    2018-01-01

    Zebrafish are increasingly used as a vertebrate model organism for various traits including swimming performance, obesity and metabolism, necessitating high-throughput protocols to generate standardized phenotypic information. Here, we propose a novel and cost-effective method for exercising zebrafish, using a coffee plunger and magnetic stirrer. To demonstrate the use of this method, we conducted a pilot experiment to show that this simple system provides repeatable estimates of maximal swim performance (intra-class correlation [ICC] = 0.34-0.41) and observe that exercise training of zebrafish on this system significantly increases their maximum swimming speed. We propose this high-throughput and reproducible system as an alternative to traditional linear chamber systems for exercising zebrafish and similarly sized fishes.

  11. Brain transcriptome variation among behaviorally distinct strains of zebrafish (Danio rerio

    Drew Robert E

    2012-07-01

    Full Text Available Abstract Background Domesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation. Results Compared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112 differed between domesticated and wild strains with notable genes including gpr177 (wntless, selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4. Conclusions Microarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons among microarray studies and the low level of population-level replication inherent to these studies.

  12. Hyperglycemia induces memory impairment linked to increased acetylcholinesterase activity in zebrafish (Danio rerio).

    Capiotti, Katiucia Marques; De Moraes, Daiani Almeida; Menezes, Fabiano Peres; Kist, Luiza Wilges; Bogo, Maurício Reis; Da Silva, Rosane Souza

    2014-11-01

    Diabetes mellitus, which causes hyperglycemia, affects the central nervous system and can impairs cognitive functions, such as memory. The aim of this study was to investigate the effects of hyperglycemia on memory as well as on the activity of acethylcholinesterase. Hyperglycemia was induced in adult zebrafish by immersion in glucose 111mM by 14 days. The animals were divided in 4 groups: control, glucose-treated, glucose-washout 7-days and glucose-washout 14-days. We evaluated the performance in inhibitory avoidance task and locomotor activity. We also determined acethylcholinesterase activity and gene expression from whole brain. In order to counteract the effect of hyperglycemia underlined by effects on acethylcholinesterase activity, we treated the animals with galantamine (0.05ng/g), an inhibitor of this enzyme. Also we evaluated the gene expression of insulin receptor and glucose transporter from zebrafish brain. The hyperglycemia promoted memory deficit in adult zebrafish, which can be explained by increased AChE activity. The ache mRNA levels from zebrafish brain were decrease in 111mM glucose group and returned to normal levels after 7 days of glucose withdrawal. Insulin receptors (insra-1, insra-2, insrb-1 and insrb-2) and glut-3 mRNA levels were not significantly changed. Our results also demonstrated that galantamine was able to reverse the memory deficit caused by hyperglycemia, demonstrating that these effects involve modulation of AChE activity. These data suggest that the memory impairment induced by hyperglycemia is underlined by the cholinergic dysfunction caused by the mechanisms involving the control of acetylcholinesterase function and gene expression. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Cross-Modal Learning between Visual and Vibration Signals in Zebrafish Danio Rerio

    Mu-Yun Wang

    2011-10-01

    Full Text Available Animals are always integrating environmental information from multiple sensory modalities, but the mechanisms underneath are highly underexploited. Crossmodal interactions in animal perception have been found in several species including human, mice and flies. Here we subjected zebrafish as model because its genetic effects on brain and sense organ development are well studied, but the attentional processes are mainly unexplored. Zebrafish show impressive behaviour capabilities with relatively small or “simple” brains which make their nervous system relatively more accessible to experimentation than large-brained mammals. When conditioned with both vision and vibration signals, zebrafish were able to make higher correct choices than only one sensation. After multimodal training, zebrafish were also able to transfer the memory to unimodal conditioning when only given vision or vibration signals. This study provided basic findings for how animals process multimodal sensory from the environment, and showed crossmodal interactions in zebrafish for the first time.

  14. Acute toxicity and sublethal effects of gallic and pelargonic acids on the zebrafish Danio rerio.

    Techer, Didier; Milla, Sylvain; Fontaine, Pascal; Viot, Sandrine; Thomas, Marielle

    2015-04-01

    Gallic and pelargonic acids are naturally found in a variety of plants and food products. Despite their extensive use in man-made applications, little is known regarding their potential risks to aquatic vertebrates. The aim of this work was to assess the acute toxicity of these polyphenolic and fatty acid compounds to the zebrafish. In order to get insights into sublethal effects, the enzyme activity of usual biomarkers related to oxidative stress and biotransformation were also assessed in fish. These latter included total superoxide dismutase, catalase as well as total glutathione peroxidase for antioxidant defence mechanisms and glutathione S-transferase for biotransformation related enzyme. Gallic acid was practically non-toxic (96-h lethal concentration (LC50) > 100 mg/L) whereas pelargonic acid was slightly toxic (96-h LC50 of 81.2 mg/L). Moreover, biomarker analyses indicated enhanced superoxide dismutase activity in fish exposed to 20, 40 and 100 mg/L of gallic acid compared to control. A dose-dependent induction of glutathione peroxidase and glutathione S-transferase was reported following gallic acid exposure at the tested concentrations of 10, 20 and 40 mg/L, with the exception of 100 mg/L of substance where basal activity levels were reported. In the case of pelargonic acid, there was no change in antioxidant enzyme activity while an inhibition of glutathione S-transferase was observed from organisms exposed to 45, 58 and 76 mg/L of test solution. The results concerning sublethal effects on biological parameters of zebrafish highlighted thereby the need for further investigations following chronic exposure to both organic acids.

  15. The dynamics of neutrophils in zebrafish (Danio rerio) during infection with the parasite Ichthyophthirius multifiliis

    Jørgensen, Louise von Gersdorff

    2016-01-01

    Ichthyophthirius multifiliis is a ciliated protozoan parasite infecting the skin and gills of freshwater fish. Neutrophils are attracted to the infection sites, as a part of the innate immune response. In this study a transgenic line of zebrafish (Tg(MPO:GFP)i114) with GFP-tagged neutrophils was ...... the infection. Neutrophils interacted directly with the parasites with pseudopod formation projecting towards the pathogen. These results indicate a strong innate immune response immediately following infection and/or a subsequent immune evasion by the parasite....

  16. Toxicity and cardiac effects of carbaryl in early developing zebrafish (Danio rerio) embryos

    Lin, C.C.; Hui, Michelle N.Y.; Cheng, S.H.

    2007-01-01

    Carbaryl, an acetylcholinesterase inhibitor, is known to be moderately toxic to adult zebrafish and has been reported to cause heart malformations and irregular heartbeat in medaka. We performed experiments to study the toxicity of carbaryl, specifically its effects on the heart, in early developing zebrafish embryos. LC50 and EC50 values for carbaryl at 28 h post-fertilization were 44.66 μg/ml and 7.52 μg/ml, respectively, and 10 μg/ml carbaryl was used in subsequent experiments. After confirming acetylcholinesterase inhibition by carbaryl using an enzymatic method, we observed red blood cell accumulation, delayed hatching and pericardial edema, but not heart malformation as described in some previous reports. Our chronic exposure data also demonstrated carbaryl-induced bradycardia, which is a common effect of acetylcholinesterase inhibitors due to the accumulation of acetylcholine, in embryos from 1 day post-fertilization (dpf) to 5 dpf. The distance between the sinus venosus, the point where blood enters the atrium, and the bulbus arteriosus, the point where blood leaves the ventricle, indicated normal looping of the heart tube. Immunostaining of myosin heavy chains with the ventricle-specific antibody MF20 and the atrium-specific antibody S46 showed normal development of heart chambers. At the same time, acute exposure resulted in carbaryl-induced bradycardia. Heart rate dropped significantly after a 10-min exposure to 100 μg/ml carbaryl but recovered when carbaryl was removed. The novel observation of carbaryl-induced bradycardia in 1- and 2-dpf embryos suggested that carbaryl affected cardiac function possibly through an alternative mechanism other than acetylcholinesterase inhibition such as inhibition of calcium ion channels, since acetylcholine receptors in zebrafish are not functional until 3 dpf. However, the exact nature of this mechanism is currently unknown, and thus further studies are required

  17. Evaluation of the toxic effect on zebrafish (Danio rerio) exposed to uranium mill tailings leaching solution

    Fang Geng; Nan Hu; Ji-Fang Zheng; Cheng-Lei Wang; Xin Chen; Jia Yu; De-Xin Ding

    2012-01-01

    The objective of this study was to evaluate the potential ecological danger and toxic effect of uranium mill tailings leaching solution (UMTLS) on aquatic animals. UMTLS was identified to contain two radioactive elements, nine heavy metal elements, and five non-metallic materials. The acute toxicity test indicated that the 1, 12, 24, 48, 72, 96 h LC 50 values of UMTLS to the zebrafish were 12.1, 7.1, 4.4, 3.8, 3.4, and 2.9%, respectively. In sub-lethal toxicity tests, superoxide dismutase, catalase, Na + -K + -ATPase activities, and malondialdehyde content were respectively determined and analyzed in the zebrafish gill, gonad, muscle, and liver after exposed to four different concentration levels of UMTLS for 7 and 14 days, respectively. The result showed that the most sensitivity of the antioxidant system in zebrafish tissues in UMTLS was gill, and then decreased in gonad, muscle and liver respectively. Na + -K + -ATPase activity in the liver and gonad may be considered as a reference biomarker of UMTLS stress. The data in this study may be valuable that the toxicity of such as the leaching solution of potentially hazardous material was compared with that of each constituent. (author)

  18. Sodium and chloride transport in soft water and hard water acclimated zebrafish (Danio rerio)

    Boisen, A M Z; Amstrup, J; Novak, I

    2003-01-01

    pump activity, changes in abundance and possibly localization of this protein did not appear to contribute to soft water acclimation. Active Cl(-) uptake was strongly dependent on branchial carbonic anhydrase (CA) activity regardless of water type, while the response of Na(+) transport to a CA...

  19. In Vivo toxicological assessment of biologically synthesized silver nanoparticles in adult Zebrafish (Danio rerio)

    Krishnaraj, Chandran, E-mail: krishnarajbio@gmail.com [Department of Food Science & Technology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Harper, Stacey L. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Yun, Soon-Il, E-mail: siyun@jbnu.ac.kr [Department of Food Science & Technology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2016-01-15

    Highlights: • Synthesis of AgNPs achieved using Malva crispa Linn., leaves extract. • 96 h LC{sub 50} concentration of AgNPs was observed at 142.2 μg/l in adult zebrafish. • Cytological changes and intrahepatic localization of AgNPs were demonstrated in tissues. • Presence of micronuclei and nuclear abnormalities were observed. • The mRNA expression of stress and immune response related genes were analyzed. - Abstract: The present study examines the deleterious effect of biologically synthesized silver nanoparticles in adult zebrafish. Silver nanoparticles (AgNPs) used in the study were synthesized by treating AgNO{sub 3} with aqueous leaves extract of Malva crispa Linn., a medicinal herb as source of reductants. LC{sub 50} concentration of AgNPs at 96 h was observed as 142.2 μg/l. In order to explore the underlying toxicity mechanisms of AgNPs, half of the LC{sub 50} concentration (71.1 μg/l) was exposed to adult zebrafish for 14 days. Cytological changes and intrahepatic localization of AgNPs were observed in gills and liver tissues respectively, and the results concluded a possible sign for oxidative stress. In addition to oxidative stress the genotoxic effect was observed in peripheral blood cells like presence of micronuclei, nuclear abnormalities and also loss in cell contact with irregular shape was observed in liver parenchyma cells. Hence to confirm the oxidative stress and genotoxic effects the mRNA expression of stress related (MTF-1, HSP70) and immune response related (TLR4, NFKB, IL1B, CEBP, TRF, TLR22) genes were analyzed in liver tissues and the results clearly concluded that the plant extract mediated synthesis of AgNPs leads to oxidative stress and immunotoxicity in adult zebrafish.

  20. Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio.

    Ozlem Yilmaz

    Full Text Available Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine.

  1. Scrambled eggs: Proteomic portraits and novel biomarkers of egg quality in zebrafish (Danio rerio).

    Yilmaz, Ozlem; Patinote, Amélie; Nguyen, Thao Vi; Com, Emmanuelle; Lavigne, Regis; Pineau, Charles; Sullivan, Craig V; Bobe, Julien

    2017-01-01

    Egg quality is a complex biological trait and a major determinant of reproductive fitness in all animals. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading biomedical model for early development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were sampled immediately after spawning and used to create pooled or replicated sample sets whose protein extracts were subjected to different levels of fractionation before liquid chromatography and tandem mass spectrometry. Obtained spectra were searched against a zebrafish proteome database and detected proteins were annotated, categorized and quantified based on normalized spectral counts. Manually curated and automated enrichment analyses revealed poor quality eggs to be deficient of proteins involved in protein synthesis and energy and lipid metabolism, and of some vitellogenin products and lectins, and to have a surfeit of proteins involved in endo-lysosomal activities, autophagy, and apoptosis, and of some oncogene products, lectins and egg envelope proteins. Results of pathway and network analyses suggest that this aberrant proteomic profile results from failure of oocytes giving rise to poor quality eggs to properly transit through final maturation, and implicated Wnt signaling in the etiology of this defect. Quantitative comparisons of abundant proteins in good versus poor quality eggs revealed 17 candidate egg quality markers. Thus, the zebrafish egg proteome is clearly linked to embryo developmental potential, a phenomenon that begs further investigation to elucidate the root causes of poor egg quality, presently a serious and intractable problem in livestock and human reproductive medicine.

  2. Influence of polyethylene microplastic beads on the uptake and localization of silver in zebrafish (Danio rerio)

    Khan, Farhan R.; Syberg, Kristian; Shashoua, Yvonne

    2015-01-01

    This study aimed to determine whether the uptake and localization of Ag in zebrafish was affected by the presence of polyethylene microplastic beads (PE MPBs). Zebrafish were exposed to 1 μg Ag L−1 (radiolabelled with 110mAg) for 4 and 24 h in the presence or absence of PE MPBs (10, 100 or 1000...... Ag uptake at both time points and also significantly increased the proportion of intestinal Ag. This study demonstrates that microplastics can alter the bioavailability and uptake route of a metal contaminant in a model fish species...

  3. Influence of polyethylene microplastic beads on the uptake and localization of silver in zebrafish (Danio rerio)

    Khan, Farhan R.; Syberg, Kristian; Shashoua, Yvonne; Bury, Nicolas R.

    2015-01-01

    This study aimed to determine whether the uptake and localization of Ag in zebrafish was affected by the presence of polyethylene microplastic beads (PE MPBs). Zebrafish were exposed to 1 μg Ag L"−"1 (radiolabelled with "1"1"0"mAg) for 4 and 24 h in the presence or absence of PE MPBs (10, 100 or 1000 MPBs mL"−"1), and one treatment in which MPBs (1000 MPBs mL"−"1) were incubated with Ag to promote adsorption. The presence of MPBs, at any of the tested doses, had no effect on the uptake or localization of Ag. However, exposure to the Ag-incubated MPBs (∽75% of the Ag bound to MPBs) significantly reduced Ag uptake at both time points and also significantly increased the proportion of intestinal Ag. This study demonstrates that microplastics can alter the bioavailability and uptake route of a metal contaminant in a model fish species. - Highlights: • Zebrafish exposed to Ag in the presence or absence of microplastic beads. • MPBs also incubated with Ag to promote adherence prior to zebrafish exposure. • Presence of MPBs (at any dose) had no impact on uptake or localization of Ag. • Bound to MPBs, Ag less available, but greater localization to intestine. • Study shows that MPBs can change the bioavailability and uptake route of a metal. - Silver bioavailability and uptake route in fish affected by adsorption to microplastic beads.

  4. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    Barillet, Sabrina; Adam-Guillermin, Christelle; Palluel, Olivier; Porcher, Jean-Marc; Devaux, Alain

    2011-01-01

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: → Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 μg/L. → Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. → DNA damage is induced in red blood cells after 20 d of exposure to 500 μg DU/L. → The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  5. Exercise quantity-dependent muscle hypertrophy in adult zebrafish (Danio rerio).

    Hasumura, Takahiro; Meguro, Shinichi

    2016-07-01

    Exercise is very important for maintaining and increasing skeletal muscle mass, and is particularly important to prevent and care for sarcopenia and muscle disuse atrophy. However, the dose-response relationship between exercise quantity, duration/day, and overall duration and muscle mass is poorly understood. Therefore, we investigated the effect of exercise duration on skeletal muscle to reveal the relationship between exercise quantity and muscle hypertrophy in zebrafish forced to exercise. Adult male zebrafish were exercised 6 h/day for 4 weeks, 6 h/day for 2 weeks, or 3 h/day for 2 weeks. Flow velocity was adjusted to maximum velocity during continual swimming (initial 43 cm/s). High-speed consecutive photographs revealed that zebrafish mainly drove the caudal part. Additionally, X-ray micro computed tomography measurements indicated muscle hypertrophy of the mid-caudal half compared with the mid-cranial half part. The cross-sectional analysis of the mid-caudal half muscle revealed that skeletal muscle (red, white, or total) mass increased with increasing exercise quantity, whereas that of white muscle and total muscle increased only under the maximum exercise load condition of 6 h/day for 4 weeks. Additionally, the muscle fiver size distributions of exercised fish were larger than those from non-exercised fish. We revealed that exercise quantity, duration/day, and overall duration were correlated with skeletal muscle hypertrophy. The forced exercise model enabled us to investigate the relationship between exercise quantity and skeletal muscle mass. These results open up the possibility for further investigations on the effects of exercise on skeletal muscle in adult zebrafish.

  6. Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio.

    Hata, Hiroki; Hori, Michio

    2012-01-01

    The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.

  7. Molecular cloning and developmental expression of Tlx (Hox11) genes in zebrafish (Danio rerio).

    Langenau, D M; Palomero, T; Kanki, J P; Ferrando, A A; Zhou, Y; Zon, L I; Look, A T

    2002-09-01

    Tlx (Hox11) genes are orphan homeobox genes that play critical roles in the regulation of early developmental processes in vertebrates. Here, we report the identification and expression patterns of three members of the zebrafish Tlx family. These genes share similar, but not identical, expression patterns with other vertebrate Tlx-1 and Tlx-3 genes. Tlx-1 is expressed early in the developing hindbrain and pharyngeal arches, and later in the putative splenic primordium. However, unlike its orthologues, zebrafish Tlx-1 is not expressed in the cranial sensory ganglia or spinal cord. Two homologues of Tlx-3 were identified: Tlx-3a and Tlx-3b, which are both expressed in discrete regions of the developing nervous system, including the cranial sensory ganglia and Rohon-Beard neurons. However, only Tlx-3a is expressed in the statoacoustic cr