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Sample records for teleost haplochromis burtoni

  1. The skeletal ontogeny of Astatotilapia burtoni - a direct-developing model system for the evolution and development of the teleost body plan.

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    Woltering, Joost M; Holzem, Michaela; Schneider, Ralf F; Nanos, Vasilios; Meyer, Axel

    2018-04-03

    The experimental approach to the evolution and development of the vertebrate skeleton has to a large extent relied on "direct-developing" amniote model organisms, such as the mouse and the chicken. These organisms can however only be partially informative where it concerns secondarily lost features or anatomical novelties not present in their lineages. The widely used anamniotes Xenopus and zebrafish are "indirect-developing" organisms that proceed through an extended time as free-living larvae, before adopting many aspects of their adult morphology, complicating experiments at these stages, and increasing the risk for lethal pleiotropic effects using genetic strategies. Here, we provide a detailed description of the development of the osteology of the African mouthbrooding cichlid Astatotilapia burtoni, primarily focusing on the trunk (spinal column, ribs and epicentrals) and the appendicular skeleton (pectoral, pelvic, dorsal, anal, caudal fins and scales), and to a lesser extent on the cranium. We show that this species has an extremely "direct" mode of development, attains an adult body plan within 2 weeks after fertilization while living off its yolk supply only, and does not pass through a prolonged larval period. As husbandry of this species is easy, generation time is short, and the species is amenable to genetic targeting strategies through microinjection, we suggest that the use of this direct-developing cichlid will provide a valuable model system for the study of the vertebrate body plan, particularly where it concerns the evolution and development of fish or teleost specific traits. Based on our results we comment on the development of the homocercal caudal fin, on shared ontogenetic patterns between pectoral and pelvic girdles, and on the evolution of fin spines as novelty in acanthomorph fishes. We discuss the differences between "direct" and "indirect" developing actinopterygians using a comparison between zebrafish and A. burtoni development.

  2. Distribution and female reproductive state differences in orexigenic and anorexigenic neurons in the brain of the mouth brooding African cichlid fish, Astatotilapia burtoni.

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    Porter, Danielle T; Roberts, David A; Maruska, Karen P

    2017-10-01

    Integration of reproduction and metabolism is necessary for species survival. While the neural circuits controlling energy homeostasis are well-characterized, the signals controlling the relay of nutritional information to the reproductive axis are less understood. The cichlid fish Astatotilapia burtoni is ideal for studying the neural regulation of feeding and reproduction because females cycle between a feeding gravid state and a period of forced starvation while they brood developing young inside their mouths. To test the hypothesis that candidate neuropeptide-containing neurons known to be involved in feeding and energy homeostasis in mammals show conserved distribution patterns, we performed immunohistochemistry and in situ hybridization to localize appetite-stimulating (neuropeptide Y, NPY; agouti-related protein, AGRP) and appetite-inhibiting (cocaine and amphetamine-regulated transcript, CART; pro-opiomelanocortin, pomc1a) neurons in the brain. NPY, AGRP, CART, and pomc1a somata showed distribution patterns similar to other teleosts, which included localization to the lateral tuberal nucleus (NLT), the putative homolog of the mammalian arcuate nucleus. Gravid females also had larger NPY and AGRP neurons in the NLT compared to brooding females, but brooding females had larger pomc1a neurons compared to gravid females. Hypothalamic agrp mRNA levels were also higher in gravid compared to brooding females. Thus, larger appetite-stimulating neurons (NPY, AGRP) likely promote feeding while females are gravid, while larger pomc1a neurons may act as a signal to inhibit food intake during mouth brooding. Collectively, our data suggest a potential role for NPY, AGRP, POMC, and CART in regulating energetic status in A. burtoni females during varying metabolic and reproductive demands. © 2017 Wiley Periodicals, Inc.

  3. Metamorphosis in Teleosts

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    McMenamin, Sarah K.; Parichy, David M.

    2017-01-01

    Teleosts are the largest and most diverse group of vertebrates, and many species undergo morphological, physiological, and behavioral transitions, “metamorphoses,” as they progress between morphologically divergent life stages. The larval metamorphosis that generally occurs as teleosts mature from larva to juvenile involves the loss of embryo-specific features, the development of new adult features, major remodeling of different organ systems, and changes in physical proportions and overall phenotype. Yet, in contrast to anuran amphibians, for example, teleost metamorphosis can entail morphological change that is either sudden and profound, or relatively gradual and subtle. Here, we review the definition of metamorphosis in teleosts, the diversity of teleost metamorphic strategies and the transitions they involve, and what is known of their underlying endocrine and genetic bases. We suggest that teleost metamorphosis offers an outstanding opportunity for integrating our understanding of endocrine mechanisms, cellular processes of morphogenesis and differentiation, and the evolution of diverse morphologies and life histories. PMID:23347518

  4. The Integrated Genomic Architecture and Evolution of Dental Divergence in East African Cichlid Fishes (Haplochromis chilotes x H. nyererei

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    C. Darrin Hulsey

    2017-09-01

    Full Text Available The independent evolution of the two toothed jaws of cichlid fishes is thought to have promoted their unparalleled ecological divergence and species richness. However, dental divergence in cichlids could exhibit substantial genetic covariance and this could dictate how traits like tooth numbers evolve in different African Lakes and on their two jaws. To test this hypothesis, we used a hybrid mapping cross of two trophically divergent Lake Victoria species (Haplochromis chilotes × Haplochromis nyererei to examine genomic regions associated with cichlid tooth diversity. Surprisingly, a similar genomic region was found to be associated with oral jaw tooth numbers in cichlids from both Lake Malawi and Lake Victoria. Likewise, this same genomic location was associated with variation in pharyngeal jaw tooth numbers. Similar relationships between tooth numbers on the two jaws in both our Victoria hybrid population and across the phylogenetic diversity of Malawi cichlids additionally suggests that tooth numbers on the two jaws of haplochromine cichlids might generally coevolve owing to shared genetic underpinnings. Integrated, rather than independent, genomic architectures could be key to the incomparable evolutionary divergence and convergence in cichlid tooth numbers.

  5. Genetic variation and demographic history of the Haplochromis laparogramma group of Lake Victoria-An analysis based on SINEs and mitochondrial DNA.

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    Mzighani, Semvua I; Nikaido, Masato; Takeda, Miyuki; Seehausen, Ole; Budeba, Yohana L; Ngatunga, Benjamin P; Katunzi, Egid F B; Aibara, Mitsuto; Mizoiri, Shinji; Sato, Tetsu; Tachida, Hidenori; Okada, Norihiro

    2010-01-15

    More than 500 endemic haplochromine cichlid species inhabit Lake Victoria. This striking species diversity is a classical example of recent explosive adaptive radiation thought to have happened within the last approximately 15,000 years. In this study, we examined the population structure and historical demography of 3 pelagic haplochromine cichlid species that resemble in morphology and have similar niche, Haplochromis (Yssichromis) laparogramma, Haplochromis (Y.) pyrrhocephalus, and Haplochromis (Y.) sp. "glaucocephalus". We investigated the sequences of the mitochondrial DNA control region and the insertion patterns of short interspersed elements (SINEs) of 759 individuals. We show that sympatric forms are genetically differentiated in 4 of 6 cases, but we also found apparent weakening of the genetic differentiation in areas with turbid water. We estimated the timings of population expansion and species divergence to coincide with the refilling of the lake at the Pleistocene/Holocene boundary. We also found that estimates can be altered significantly by the choice of the shape of the molecular clock. If we employ the nonlinear clock model of evolutionary rates in which the rates are higher towards the recent, the population expansion was dated at around the event of desiccation of the lake ca. 17,000 YBP. Thus, we succeeded in clarifying the species and population structure of closely related Lake Victoria cichlids and in showing the importance of applying appropriate clock calibrations in elucidating recent evolutionary events.

  6. Parental investment matters for maternal and offspring immune defense in the mouthbrooding cichlid Astatotilapia burtoni.

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    Keller, Isabel S; Salzburger, Walter; Roth, Olivia

    2017-12-20

    Parental care, while increasing parental fitness through offspring survival, also bears cost to the care-giving parent. Consequentially, trade offs between parental care and other vitally important traits, such as the immune system seem evident. In co-occurring phases of parental care and immunological challenges negative consequences through a resource allocation trade off on both the parental and the offspring conditions can be predicted. While the immune system reflects parental stress conditions, parental immunological investments also boost offspring survival via the transfer of immunological substances (trans-generational immune priming). We investigated this relationship in the mouthbrooding East African cichlid Astotatilapia burtoni. Prior to mating, females were exposed to an immunological activation, while others remained immunologically naïve. Correspondingly, the immunological status of females was either examined directly after reproduction or after mouthbrooding had ceased. Offspring from both groups were exposed to immunological challenges to assess the extent of trans-generational immune priming. As proxy for immune status, cellular immunological activity and gene expression were determined. Both reproducing and mouthbrooding females allocate their resources towards reproduction. While upon reproduction the innate immune system was impeded, mouthbrooding females showed an attenuation of inflammatory components. Juveniles from immune challenged mouthbrooding females showed downregulation of immune and life history candidate genes, implying a limitation of trans-generational plasticity when parents experience stress during the costly reproductive phase. Our results provide evidence that both parental investment via mouthbrooding and the rise of the immunological activity upon an immune challenge are costly traits. If applied simultaneously, not only mothers seem to be impacted in their performance, but also offspring are impeded in their ability to

  7. MHC and Evolution in Teleosts

    OpenAIRE

    Grimholt, Unni

    2016-01-01

    Major histocompatibility complex (MHC) molecules are key players in initiating immune responses towards invading pathogens. Both MHC class I and class II genes are present in teleosts, and, using phylogenetic clustering, sequences from both classes have been classified into various lineages. The polymorphic and classical MHC class I and class II gene sequences belong to the U and A lineages, respectively. The remaining class I and class II lineages contain nonclassical gene sequences that, de...

  8. Teleost Chemokines and Their Receptors

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    Steve Bird

    2015-11-01

    Full Text Available Chemokines are a superfamily of cytokines that appeared about 650 million years ago, at the emergence of vertebrates, and are responsible for regulating cell migration under both inflammatory and physiological conditions. The first teleost chemokine gene was reported in rainbow trout in 1998. Since then, numerous chemokine genes have been identified in diverse fish species evidencing the great differences that exist among fish and mammalian chemokines, and within the different fish species, as a consequence of extensive intrachromosomal gene duplications and different infectious experiences. Subsequently, it has only been possible to establish clear homologies with mammalian chemokines in the case of some chemokines with well-conserved homeostatic roles, whereas the functionality of other chemokine genes will have to be independently addressed in each species. Despite this, functional studies have only been undertaken for a few of these chemokine genes. In this review, we describe the current state of knowledge of chemokine biology in teleost fish. We have mainly focused on those species for which more research efforts have been made in this subject, specially zebrafish (Danio rerio, rainbow trout (Oncorhynchus mykiss and catfish (Ictalurus punctatus, outlining which genes have been identified thus far, highlighting the most important aspects of their expression regulation and addressing any known aspects of their biological role in immunity. Finally, we summarise what is known about the chemokine receptors in teleosts and provide some analysis using recently available data to help characterise them more clearly.

  9. Chemokines in teleost fish species.

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    Alejo, Alí; Tafalla, Carolina

    2011-12-01

    Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues which in mammals can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in their sequence: CXC (α), CC (β), C and CX(3)C classes. Evolutionarily, fish can be considered as an intermediate step between species which possess only innate immunity (invertebrates) and species with a fully developed acquired immune network such as mammals. Therefore, the functionality of their different immune cell types and molecules is sometimes also intermediate between innate and acquired responses. The first chemokine gene identified in a teleost was a rainbow trout (Oncorhynchus mykiss) chemokine designated as CK1 in 1998. Since then, many different chemokine genes have been identified in several fish species, but their role in homeostasis and immune response remains largely unknown. Extensive genomic duplication events and the fact that chemokines evolve more quickly than other immune genes, make it very difficult to establish true orthologues between fish and mammalian chemokines that would help us with the ascription of immune roles. In this review, we describe the current state of knowledge of chemokine biology in teleost fish, focusing mainly on which genes have been identified so far and highlighting the most important aspects of their expression regulation, due to the great lack of functional information available for them. As the number of chemokine genes begins to close down for some teleost species, there is an important need for functional assays that may elucidate the role of each of these molecules within the fish immune response. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. The Mucosal Immune System of Teleost Fish

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    Irene Salinas

    2015-08-01

    Full Text Available Teleost fish possess an adaptive immune system associated with each of their mucosal body surfaces. Evidence obtained from mucosal vaccination and mucosal infection studies reveal that adaptive immune responses take place at the different mucosal surfaces of teleost. The main mucosa-associated lymphoid tissues (MALT of teleosts are the gut-associated lymphoid tissue (GALT, skin-associated lymphoid tissue (SALT, the gill-associated lymphoid tissue (GIALT and the recently discovered nasopharynx-associated lymphoid tissue (NALT. Teleost MALT includes diffuse B cells and T cells with specific phenotypes different from their systemic counterparts that have co-evolved to defend the microbe-rich mucosal environment. Both B and T cells respond to mucosal infection or vaccination. Specific antibody responses can be measured in the gills, gut and skin mucosal secretions of teleost fish following mucosal infection or vaccination. Rainbow trout studies have shown that IgT antibodies and IgT+ B cells are the predominant B cell subset in all MALT and respond in a compartmentalized manner to mucosal infection. Our current knowledge on adaptive immunity in teleosts is limited compared to the mammalian literature. New research tools and in vivo models are currently being developed in order to help reveal the great intricacy of teleost mucosal adaptive immunity and help improve mucosal vaccination protocols for use in aquaculture.

  11. [Annotation of the mobilomes of nine teleost species].

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    Gao, Bo; Shen, Dan; Chen, Cai; Wang, Saisai; Yang, Kunlun; Chen, Wei; Wang, Wei; Zhang, Li; Song, Chengyi

    2018-01-25

    In this study, the mobilomes of nine teleost species were annotated by bioinformatics methods. Both of the mobilome size and constitute displayed a significant difference in 9 species of teleost fishes. The species of mobilome content ranking from high to low were zebrafish, medaka, tilapia, coelacanth, platyfish, cod, stickleback, tetradon and fugu. Mobilome content and genome size were positively correlated. The DNA transposons displayed higher diversity and larger variation in teleost (0.50% to 38.37%), was a major determinant of differences in teleost mobilomes, and hAT and Tc/Mariner superfamily were the major DNA transposons in teleost. RNA transposons also exhibited high diversity in teleost, LINE transposons accounted for 0.53% to 5.75% teleost genomic sequences, and 14 superfamilies were detected. L1, L2, RTE and Rex retrotransposons obtained significant amplification. While LTR displayed low amplification in most teleost with less than 2% of genome coverages, except in zebrafish and stickleback, where LTR reachs 5.58% and 2.51% of genome coverages respectively. And 6 LTR superfamilies (Copia, DIRS, ERV, Gypsy, Ngaro and Pao) were detected in the teleost, and Gypsy exhibits obvious amplication among them. While the SINE represents the weakest ampification types in teleost, only within zebrafish and coelacanth, it represents 3.28% and 5.64% of genome coverages, in the other 7 teleost, it occupies less than 1% of genomes, and tRNA, 5S and MIR families of SINE have a certain degree of amplification in some teleosts. This study shows that the teleost display high diversity and large variation of mobilome, there is a strong correlation with the size variations of genomes and mobilome contents in teleost, mobilome is an important factor in determining the teleost genome size.

  12. Individual differences in cognition among teleost fishes.

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    Lucon-Xiccato, Tyrone; Bisazza, Angelo

    2017-08-01

    Individual differences in cognitive abilities have been thoroughly investigated in humans and to a lesser extent in other mammals. Despite the growing interest in studying cognition in other taxonomic groups, data on individual differences are scarce for non-mammalian species. Here, we review the literature on individual differences in cognitive abilities in teleost fishes. Relatively few studies have directly addressed this topic and have provided evidence of consistent and heritable individual variation in cognitive abilities in fish. We found much more evidence of individual cognitive differences in other research areas, namely sex differences, personality differences, cerebral lateralisation and comparison between populations. Altogether, these studies suggest that individual differences in cognition are as common in fish as in warm-blooded vertebrates. Based on the example of research on mammals, we suggest directions for future investigation in fish. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The GC-heterogeneity of teleost fishes

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    Gautier Christian

    2008-12-01

    Full Text Available Abstract Background One of the most striking features of mammalian and birds chromosomes is the variation in the guanine-cytosine (GC content that occurs over scales of hundreds of kilobases to megabases; this is known as the "isochore" structure. Among other vertebrates the presence of isochores depends upon the taxon; isochore are clearly present in Crocodiles and turtles but fish genome seems very homogeneous on GC content. This has suggested a unique isochore origin after the divergence between Sarcopterygii and Actinopterygii, but before that between Sauropsida and mammals. However during more than 30 years of analysis, isochore characteristics have been studied and many important biological properties have been associated with the isochore structure of human genomes. For instance, the genes are more compact and their density is highest in GC rich isochores. Results This paper shows in teleost fish genomes the existence of "GC segmentation" sharing some of the characteristics of isochores although teleost fish genomes presenting a particular homogeneity in CG content. The entire genomes of T nigroviridis and D rerio are now available, and this has made it possible to check whether a mosaic structure associated with isochore properties can be found in these fishes. In this study, hidden Markov models were trained on fish genes (T nigroviridis and D rerio which were classified by using the isochore class of their human orthologous. A clear segmentation of these genomes was detected. Conclusion The GC content is an excellent indicator of isochores in heterogeneous genomes as mammals. The segmentation we obtained were well correlated with GC content and other properties associated to GC content such as gene density, the number of exons per gene and the length of introns. Therefore, the GC content is the main property that allows the detection of isochore but more biological properties have to be taken into account. This method allows detecting

  14. Recruitment and growth patterns of juvenile marine teleosts caught ...

    African Journals Online (AJOL)

    teleosts caught at King's Beach, Algoa Bay. Theresa A. ... about by the arrival of larvae/juveniles in the plankton, followed ..... Species composition and length distribution in the ... abundance and diversity of the Swartkops estuary ichthyofauna.

  15. Lack of plasma kallikrein-kinin system cascade in teleosts.

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    Marty Kwok-Shing Wong

    Full Text Available The kallikrein-kinin system (KKS consists of two major cascades in mammals: "plasma KKS" consisting of high molecular-weight (HMW kininogen (KNG, plasma kallikrein (KLKB1, and bradykinin (BK; and "tissue KKS" consisting of low molecular-weight (LMW KNG, tissue kallikreins (KLKs, and [Lys(0]-BK. Some components of the KKS have been identified in the fishes, but systematic analyses have not been performed, thus this study aims to define the KKS components in teleosts and pave a way for future physiological and evolutionary studies. Through a combination of genomics, molecular, and biochemical methods, we showed that the entire plasma KKS cascade is absent in teleosts. Instead of two KNGs as found in mammals, a single molecular weight KNG was found in various teleosts, which is homologous to the mammalian LMW KNG. Results of molecular phylogenetic and synteny analyses indicated that the all current teleost genomes lack KLKB1, and its unique protein structure, four apple domains and one trypsin domain, could not be identified in any genome or nucleotide databases. We identified some KLK-like proteins in teleost genomes by synteny and conserved domain analyses, which could be the orthologs of tetrapod KLKs. A radioimmunoassay system was established to measure the teleost BK and we found that [Arg(0]-BK is the major circulating form instead of BK, which supports that the teleost KKS is similar to the mammalian tissue KKS. Coincidently, coelacanths are the earliest vertebrate that possess both HMW KNG and KLKB1, which implies that the plasma KKS could have evolved in the early lobe-finned fish and descended to the tetrapod lineage. The co-evolution of HMW KNG and KLKB1 in lobe-finned fish and early tetrapods may mark the emergence of the plasma KKS and a contact activation system in blood coagulation, while teleosts may have retained a single KKS cascade.

  16. Neuropsychology of learning and memory in teleost fish.

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    Salas, Cosme; Broglio, Cristina; Durán, Emilio; Gómez, Antonia; Ocaña, Francisco M; Jiménez-Moya, Fernando; Rodríguez, Fernando

    2006-01-01

    Traditionally, brain and behavior evolution was viewed as an anagenetic process that occurred in successive stages of increasing complexity and advancement. Fishes, considered the most primitive vertebrates, were supposed to have a scarcely differentiated telencephalon, and limited learning capabilities. However, recent developmental, neuroanatomical, and functional data indicate that the evolution of brain and behavior may have been more conservative than previously thought. Experimental data suggest that the properties and neural basis of learning and memory are notably similar among teleost fish and land vertebrates. For example, lesion studies show that the teleost cerebellum is essential in classical conditioning of discrete motor responses. The lateral telencephalic pallium of the teleost fish, proposed as homologous to the hippocampus, is selectively involved in spatial learning and memory, and in trace classical conditioning. In contrast, the medial pallium, considered homologous to the amygdala, is involved in emotional conditioning in teleost fish. The data reviewed here show a remarkable parallelism between mammals and teleost fish concerning the role of different brain centers in learning and memory and cognitive processes. These evidences suggest that these separate memory systems could have appeared early during the evolution of vertebrates, having been conserved through phylogenesis.

  17. Appetite-Controlling Endocrine Systems in Teleosts

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    Rønnestad, Ivar; Gomes, Ana S.; Murashita, Koji; Angotzi, Rita; Jönsson, Elisabeth; Volkoff, Hélène

    2017-01-01

    Mammalian studies have shaped our understanding of the endocrine control of appetite and body weight in vertebrates and provided the basic vertebrate model that involves central (brain) and peripheral signaling pathways as well as environmental cues. The hypothalamus has a crucial function in the control of food intake, but other parts of the brain are also involved. The description of a range of key neuropeptides and hormones as well as more details of their specific roles in appetite control continues to be in progress. Endocrine signals are based on hormones that can be divided into two groups: those that induce (orexigenic), and those that inhibit (anorexigenic) appetite and food consumption. Peripheral signals originate in the gastrointestinal tract, liver, adipose tissue, and other tissues and reach the hypothalamus through both endocrine and neuroendocrine actions. While many mammalian-like endocrine appetite-controlling networks and mechanisms have been described for some key model teleosts, mainly zebrafish and goldfish, very little knowledge exists on these systems in fishes as a group. Fishes represent over 30,000 species, and there is a large variability in their ecological niches and habitats as well as life history adaptations, transitions between life stages and feeding behaviors. In the context of food intake and appetite control, common adaptations to extended periods of starvation or periods of abundant food availability are of particular interest. This review summarizes the recent findings on endocrine appetite-controlling systems in fish, highlights their impact on growth and survival, and discusses the perspectives in this research field to shed light on the intriguing adaptations that exist in fish and their underlying mechanisms. PMID:28458653

  18. Vertebrate Osmoregulation: A Student Laboratory Exercise Using Teleost Fish

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    Boily P.; Rees, B. B.; Williamson, L. A. C.

    2007-01-01

    Here, we describe a laboratory experiment as part of an upper-level vertebrate physiology course for biology majors to investigate the physiological response of vertebrates to osmoregulatory challenges. The experiment involves measuring plasma osmolality and Na[superscript +] -K[superscript +] -ATPase activity in gill tissue of teleost fish…

  19. Stress and fear responses in the teleost pallium

    DEFF Research Database (Denmark)

    Silva, Patricia Isabel da Mota E.; Martins, C.I.M.; Khan, Uniza Wahid

    2015-01-01

    Evolution has resulted in behavioural responses to threat which show extensive similarities between different animal species. The reaction to predator cues is one example of such prevailing responses, and functional homologies to mammalian limbic regions involved in threat-sensitive behaviour hav...... to chemical alarm cues, but this effect did not reach the level of statistical significance. Hence, limbic responses to stress and fear, akin to those seen in extant mammals, are also present in the teleost lineage...

  20. Central Pathways Integrating Metabolism and Reproduction in Teleosts

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    Shahjahan, Md.; Kitahashi, Takashi; Parhar, Ishwar S.

    2014-01-01

    Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts. PMID:24723910

  1. A phylogenetic perspective on the evolution of Mediterranean teleost fishes.

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    Christine N Meynard

    Full Text Available The Mediterranean Sea is a highly diverse, highly studied, and highly impacted biogeographic region, yet no phylogenetic reconstruction of fish diversity in this area has been published to date. Here, we infer the timing and geographic origins of Mediterranean teleost species diversity using nucleotide sequences collected from GenBank. We assembled a DNA supermatrix composed of four mitochondrial genes (12S ribosomal DNA, 16S ribosomal DNA, cytochrome c oxidase subunit I and cytochrome b and two nuclear genes (rhodopsin and recombination activating gene I, including 62% of Mediterranean teleost species plus 9 outgroups. Maximum likelihood and Bayesian phylogenetic and dating analyses were calibrated using 20 fossil constraints. An additional 124 species were grafted onto the chronogram according to their taxonomic affinity, checking for the effects of taxonomic coverage in subsequent diversification analyses. We then interpreted the time-line of teleost diversification in light of Mediterranean historical biogeography, distinguishing non-endemic natives, endemics and exotic species. Results show that the major Mediterranean orders are of Cretaceous origin, specifically ~100-80 Mya, and most Perciformes families originated 80-50 Mya. Two important clade origin events were detected. The first at 100-80 Mya, affected native and exotic species, and reflects a global diversification period at a time when the Mediterranean Sea did not yet exist. The second occurred during the last 50 Mya, and is noticeable among endemic and native species, but not among exotic species. This period corresponds to isolation of the Mediterranean from Indo-Pacific waters before the Messinian salinity crisis. The Mediterranean fish fauna illustrates well the assembly of regional faunas through origination and immigration, where dispersal and isolation have shaped the emergence of a biodiversity hotspot.

  2. PIXE analysis of otoliths from several species of teleost fish

    International Nuclear Information System (INIS)

    Arai, Nobuaki; Sakamoto, Wataru; Maeda, Kuniko.

    1994-01-01

    In-air PIXE was used to analyze trace elements in otoliths from several species of teleost fish in order to examine the correlation between the trace elements concentrations and environmental conditions. Mn, Fe, Zn and Sr were detected accurately in the order of ppm by using the in-air PIXE. It seemed that concentrations of Sr and Zn in red sea bream otoliths increased in proportion to higher seawater temperature. In addition, there were significant differences in trace element composition between that of reared red sea bream and rockfish and that of wild ones. Preliminary results indicate that the PIXE is a powerful technique to investigate fish otoliths. (author)

  3. Aspects of the biology of three benthic-feeding teleosts from King's ...

    African Journals Online (AJOL)

    Aspects of the biology of three benthic-feeding teleosts from King's Beach, Algoa Bay. Theresa A. Lasiak. Department of Zoology, University of Port Elizabeth, Port Elizabeth. The lengths, abundance pattems and feeding habits of three species of benthic·feeding teleosts, Lithognathus mormyrus,. Lithognathus lithognathus ...

  4. Phagocytosis in Teleosts. Implications of the New Cells Involved

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    María Ángeles Esteban

    2015-12-01

    Full Text Available Phagocytosis is the process by which cells engulf some solid particles to form internal vesicles known as phagosomes. Phagocytosis is in fact a specific form of endocytosis involving the vesicular interiorization of particles. Phagocytosis is essentially a defensive reaction against infection and invasion of the body by foreign substances and, in the immune system, phagocytosis is a major mechanism used to remove pathogens and/or cell debris. For these reasons, phagocytosis in vertebrates has been recognized as a critical component of the innate and adaptive immune responses to pathogens. Furthermore, more recent studies have revealed that phagocytosis is also crucial for tissue homeostasis and remodeling. Professional phagocytes in teleosts are monocyte/macrophages, granulocytes and dendritic cells. Nevertheless, in recent years phagocytic properties have also been attributed to teleost lymphocytes and thrombocytes. The possible implications of such cells on this important biological process, new factors affecting phagocytosis, evasion of phagocytosis or new forms of phagocytosis will be considered and discussed.

  5. Branchial placenta in the viviparous teleost Ilyodon whitei (Goodeidae).

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    Uribe, Mari Carmen; De la Rosa-Cruz, Gabino; García-Alarcón, Adriana

    2014-12-01

    Intraluminal gestation, as it occurs in viviparous goodeids, allows a wide diversity of embryo-maternal metabolic exchanges. The branchial placenta occurs in embryos developing in intraluminal gestation when ovarian folds enter through the operculum, into the branchial chamber. The maternal ovarian folds may extend to the embryonic pharyngeal cavity. A branchial placenta has been observed in few viviparous teleosts, and there are not previous histological analyses. This study analysis the histological structure in the goodeid Ilyodon whitei. The moterno ovarian folds extend through the embryonic operculum and reach near the gills, occupying part of the branchial chamber. These folds extend also into the pharyngeal cavity. In some regions, the epithelia of the ovarian folds and embryo were in apposition, developing a placental structure in which, maternal and embryonic capillaries lie in close proximity. The maternal epithelium has desquamated cells which may enter through the branchial chamber to the pharyngeal cavity and the alimentary tract. The complex processes that occur in the ovaries of viviparous teleosts, and its diverse adaptations for viviparity, as the presence of branchial placenta, are relevant in the study of the evolution of vertebrate viviparity. © 2014 Wiley Periodicals, Inc.

  6. "Brain sex differentiation" in teleosts: Emerging concepts with potential biomarkers.

    Science.gov (United States)

    Senthilkumaran, Balasubramanian; Sudhakumari, Cheni-Chery; Mamta, Sajwan-Khatri; Raghuveer, Kavarthapu; Swapna, Immani; Murugananthkumar, Raju

    2015-09-01

    "Brain sex differentiation" in teleosts is a contentious topic of research as most of the earlier reports tend to suggest that gonadal sex differentiation drives brain sex differentiation. However, identification of sex-specific marker genes in the developing brain of teleosts signifies brain-gonadal interaction during early sexual development in lower vertebrates. In this context, the influence of gonadotropin-releasing hormone (GnRH)-gonadotropin (GTH) axis on gonadal sex differentiation, if any requires in depth analysis. Presence of seabream (sb) GnRH immunoreactivity (ir-) in the brain of XY Nile tilapia was found as early as 5days post hatch (dph) followed by qualitative reduction in the preoptic area-hypothalamus region. In contrast, in the XX female brain a steady ir- of sbGnRH was evident from 15dph. Earlier studies using sea bass already implied the importance of hypothalamic gonadotropic axis completion during sex differentiation period. Such biphasic pattern of localization was also seen in pituitary GTHs using heterologous antisera in tilapia. However, more recent analysis in the same species could not detect any sexually dimorphic pattern using homologous antisera for pituitary GTHs. Detailed studies on the development of hypothalamo-hypophyseal-gonadal axis in teleosts focusing on hypothalamic monoamines (MA) and MA-related enzymes demonstrated sex-specific differential expression of tryptophan hydroxylase (Tph) in the early stages of developing male and female brains of tilapia and catfish. The changes in Tph expression was in agreement with the levels of serotonin (5-HT) and 5-hydroxytryptophan in the preoptic area-hypothalamus. Considering the stimulatory influence of 5-HT on GnRH and GTH release, it is possible to propose a network association between these correlates during early development, which may bring about brain sex dimorphism in males. A recent study from our laboratory during female brain sex development demonstrated high expression of

  7. Phylogenetic consistencies among chondrichthyan and teleost fishes in their bioaccumulation of multiple trace elements from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Jeffree, Ross A., E-mail: R.Jeffree@iaea.org [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco); Oberhansli, Francois; Teyssie, Jean-Louis [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco)

    2010-07-15

    Multi-tracer experiments determined the accumulation from seawater of selected radioactive trace elements (Mn-54, Co-60, Zn-65, Cs-134, Am-241, Cd-109, Ag-110m, Se-75 and Cr-51) by three teleost and three chondrichthyan fish species to test the hypothesis that these phylogenetic groups have different bioaccumulation characteristics, based on previously established contrasts between the carcharhiniform chondrichthyan Scyliorhinus canicula (dogfish) and the pleuronectiform teleost Psetta maxima (turbot). Discriminant function analysis on whole body: water concentration factors (CFs) separated dogfish and turbot in two independent experiments. Classification functions grouped the perciform teleosts, seabream (Sparus aurata) and seabass (Dicentrarchus labrax), with turbot and grouped the chondrichthyans, undulate ray (Raja undulata; Rajiformes) and spotted torpedo (Torpedo marmorata; Torpediniformes), with dogfish, thus supporting our hypothesis. Hierarchical classificatory, multi-dimensional scaling and similarity analyses based on the CFs for the nine radiotracers, also separated all three teleosts (that aggregated lower in the hierarchy) from the three chondrichthyan species. The three chondrichthyans were also more diverse amongst themselves compared to the three teleosts. Particular trace elements that were more important in separating teleosts and chondrichthyans were Cs-134 that was elevated in teleosts and Zn-65 that was elevated in chondrichthyans, these differences being due to their differential rates of uptake rather than loss. Chondrichthyans were also higher in Cr-51, Co-60, Ag-110m and Am-241, whereas teleosts were higher only in Mn-54. These contrasts in bioaccumulation patterns between teleosts and chondrichthyans are interpreted in the context of both proximate causes of underlying differences in physiology and anatomy, as well as the ultimate cause of their evolutionary divergence over more than 500 million years before present (MyBP). Our results

  8. Phylogenetic consistencies among chondrichthyan and teleost fishes in their bioaccumulation of multiple trace elements from seawater

    International Nuclear Information System (INIS)

    Jeffree, Ross A.; Oberhansli, Francois; Teyssie, Jean-Louis

    2010-01-01

    Multi-tracer experiments determined the accumulation from seawater of selected radioactive trace elements (Mn-54, Co-60, Zn-65, Cs-134, Am-241, Cd-109, Ag-110m, Se-75 and Cr-51) by three teleost and three chondrichthyan fish species to test the hypothesis that these phylogenetic groups have different bioaccumulation characteristics, based on previously established contrasts between the carcharhiniform chondrichthyan Scyliorhinus canicula (dogfish) and the pleuronectiform teleost Psetta maxima (turbot). Discriminant function analysis on whole body: water concentration factors (CFs) separated dogfish and turbot in two independent experiments. Classification functions grouped the perciform teleosts, seabream (Sparus aurata) and seabass (Dicentrarchus labrax), with turbot and grouped the chondrichthyans, undulate ray (Raja undulata; Rajiformes) and spotted torpedo (Torpedo marmorata; Torpediniformes), with dogfish, thus supporting our hypothesis. Hierarchical classificatory, multi-dimensional scaling and similarity analyses based on the CFs for the nine radiotracers, also separated all three teleosts (that aggregated lower in the hierarchy) from the three chondrichthyan species. The three chondrichthyans were also more diverse amongst themselves compared to the three teleosts. Particular trace elements that were more important in separating teleosts and chondrichthyans were Cs-134 that was elevated in teleosts and Zn-65 that was elevated in chondrichthyans, these differences being due to their differential rates of uptake rather than loss. Chondrichthyans were also higher in Cr-51, Co-60, Ag-110m and Am-241, whereas teleosts were higher only in Mn-54. These contrasts in bioaccumulation patterns between teleosts and chondrichthyans are interpreted in the context of both proximate causes of underlying differences in physiology and anatomy, as well as the ultimate cause of their evolutionary divergence over more than 500 million years before present (MyBP). Our results

  9. Plasmablasts and plasma cells: reconsidering teleost immune system organization.

    Science.gov (United States)

    Ye, Jianmin; Kaattari, Ilsa; Kaattari, Stephen

    2011-12-01

    Comparative immunologists have expended extensive efforts in the characterization of early fish B cell development; however, analysis of the post-antigen induction stages of antibody secreting cell (ASC) differentiation has been limited. In contrast, work with murine ASCs has resolved the physically and functionally distinct cells known as plasmablasts, the short-lived plasma cells and long-lived plasma cells. Teleost ASCs are now known to also possess comparable subpopulations, which can greatly differ in such basic functions as lifespan, antigen sensitivity, antibody secretion rate, differentiative potential, and distribution within the body. Understanding the mechanisms by which these subpopulations are produced and distributed is essential for both basic understanding in comparative immunology and practical vaccine engineering. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Evolution of space dependent growth in the teleost Astyanax mexicanus.

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    Natalya D Gallo

    Full Text Available The relationship between growth rate and environmental space is an unresolved issue in teleosts. While it is known from aquaculture studies that stocking density has a negative relationship to growth, the underlying mechanisms have not been elucidated, primarily because the growth rate of populations rather than individual fish were the subject of all previous studies. Here we investigate this problem in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling form (surface fish and several blind cave-dwelling (cavefish forms. Surface fish and cavefish are distinguished by living in spatially contrasting environments and therefore are excellent models to study the effects of environmental size on growth. Multiple controlled growth experiments with individual fish raised in confined or unconfined spaces showed that environmental size has a major impact on growth rate in surface fish, a trait we have termed space dependent growth (SDG. In contrast, SDG has regressed to different degrees in the Pachón and Tinaja populations of cavefish. Mating experiments between surface and Pachón cavefish show that SDG is inherited as a dominant trait and is controlled by multiple genetic factors. Despite its regression in blind cavefish, SDG is not affected when sighted surface fish are raised in darkness, indicating that vision is not required to perceive and react to environmental space. Analysis of plasma cortisol levels showed that an elevation above basal levels occurred soon after surface fish were exposed to confined space. This initial cortisol peak was absent in Pachón cavefish, suggesting that the effects of confined space on growth may be mediated partly through a stress response. We conclude that Astyanax reacts to confined spaces by exhibiting SDG, which has a genetic component and shows evolutionary regression during adaptation of cavefish to confined environments.

  11. Under Pressure: Interactions between Commensal Microbiota and the Teleost Immune System

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    Cecelia Kelly

    2017-05-01

    Full Text Available Commensal microorganisms inhabit every mucosal surface of teleost fish. At these surfaces, microorganisms directly and indirectly shape the teleost immune system. This review provides a comprehensive overview of how the microbiota and microbiota-derived products influence both the mucosal and systemic immune system of fish. The cross talk between the microbiota and the teleost immune system shifts significantly under stress or disease scenarios rendering commensals into opportunists or pathogens. Lessons learnt from germ-free fish models as well as from oral administration of live probiotics to fish highlight the vast impact that microbiota have on immune development, antibody production, mucosal homeostasis, and resistance to stress. Future studies should dissect the specific mechanisms by which different members of the fish microbiota and the metabolites they produce interact with pathogens, with other commensals, and with the teleost immune system.

  12. Evolutionary diversity and turn-over of sex determination in teleost fishes.

    Science.gov (United States)

    Mank, J E; Avise, J C

    2009-01-01

    Sex determination, due to the obvious association with reproduction and Darwinian fitness, has been traditionally assumed to be a relatively conserved trait. However, research on teleost fishes has shown that this need not be the case, as these animals display a remarkable diversity in the ways that they determine sex. These different mechanisms, which include constitutive genetic mechanisms on sex chromosomes, polygenic constitutive mechanisms, environmental influences, hermaphroditism, and unisexuality have each originated numerous independent times in the teleosts. The evolutionary lability of sex determination, and the corresponding rapid rate of turn-over among different modes, makes the teleost clade an excellent model with which to test theories regarding the evolution of sex determining adaptations. Much of the plasticity in sex determination likely results from the dynamic teleost genome, and recent advances in fish genetics and genomics have revealed the role of gene and genome duplication in fostering emergence and turn-over of sex determining mechanisms. 2009 S. Karger AG, Basel.

  13. Teleosts Genomics: Progress and Prospects in Disease Prevention and Control

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    Hetron Mweemba Munang’andu

    2018-04-01

    Full Text Available Genome wide studies based on conventional molecular tools and upcoming omics technologies are beginning to gain functional applications in the control and prevention of diseases in teleosts fish. Herein, we provide insights into current progress and prospects in the use genomics studies for the control and prevention of fish diseases. Metagenomics has emerged to be an important tool used to identify emerging infectious diseases for the timely design of rational disease control strategies, determining microbial compositions in different aquatic environments used for fish farming and the use of host microbiota to monitor the health status of fish. Expounding the use of antimicrobial peptides (AMPs as therapeutic agents against different pathogens as well as elucidating their role in tissue regeneration is another vital aspect of genomics studies that had taken precedent in recent years. In vaccine development, prospects made include the identification of highly immunogenic proteins for use in recombinant vaccine designs as well as identifying gene signatures that correlate with protective immunity for use as benchmarks in optimizing vaccine efficacy. Progress in quantitative trait loci (QTL mapping is beginning to yield considerable success in identifying resistant traits against some of the highly infectious diseases that have previously ravaged the aquaculture industry. Altogether, the synopsis put forth shows that genomics studies are beginning to yield positive contribution in the prevention and control of fish diseases in aquaculture.

  14. Teleosts Genomics: Progress and Prospects in Disease Prevention and Control.

    Science.gov (United States)

    Munang'andu, Hetron Mweemba; Galindo-Villegas, Jorge; David, Lior

    2018-04-04

    Genome wide studies based on conventional molecular tools and upcoming omics technologies are beginning to gain functional applications in the control and prevention of diseases in teleosts fish. Herein, we provide insights into current progress and prospects in the use genomics studies for the control and prevention of fish diseases. Metagenomics has emerged to be an important tool used to identify emerging infectious diseases for the timely design of rational disease control strategies, determining microbial compositions in different aquatic environments used for fish farming and the use of host microbiota to monitor the health status of fish. Expounding the use of antimicrobial peptides (AMPs) as therapeutic agents against different pathogens as well as elucidating their role in tissue regeneration is another vital aspect of genomics studies that had taken precedent in recent years. In vaccine development, prospects made include the identification of highly immunogenic proteins for use in recombinant vaccine designs as well as identifying gene signatures that correlate with protective immunity for use as benchmarks in optimizing vaccine efficacy. Progress in quantitative trait loci (QTL) mapping is beginning to yield considerable success in identifying resistant traits against some of the highly infectious diseases that have previously ravaged the aquaculture industry. Altogether, the synopsis put forth shows that genomics studies are beginning to yield positive contribution in the prevention and control of fish diseases in aquaculture.

  15. The spotted gar genome illuminates vertebrate evolution and facilitates human-to-teleost comparisons

    Science.gov (United States)

    Braasch, Ingo; Gehrke, Andrew R.; Smith, Jeramiah J.; Kawasaki, Kazuhiko; Manousaki, Tereza; Pasquier, Jeremy; Amores, Angel; Desvignes, Thomas; Batzel, Peter; Catchen, Julian; Berlin, Aaron M.; Campbell, Michael S.; Barrell, Daniel; Martin, Kyle J.; Mulley, John F.; Ravi, Vydianathan; Lee, Alison P.; Nakamura, Tetsuya; Chalopin, Domitille; Fan, Shaohua; Wcisel, Dustin; Cañestro, Cristian; Sydes, Jason; Beaudry, Felix E. G.; Sun, Yi; Hertel, Jana; Beam, Michael J.; Fasold, Mario; Ishiyama, Mikio; Johnson, Jeremy; Kehr, Steffi; Lara, Marcia; Letaw, John H.; Litman, Gary W.; Litman, Ronda T.; Mikami, Masato; Ota, Tatsuya; Saha, Nil Ratan; Williams, Louise; Stadler, Peter F.; Wang, Han; Taylor, John S.; Fontenot, Quenton; Ferrara, Allyse; Searle, Stephen M. J.; Aken, Bronwen; Yandell, Mark; Schneider, Igor; Yoder, Jeffrey A.; Volff, Jean-Nicolas; Meyer, Axel; Amemiya, Chris T.; Venkatesh, Byrappa; Holland, Peter W. H.; Guiguen, Yann; Bobe, Julien; Shubin, Neil H.; Di Palma, Federica; Alföldi, Jessica; Lindblad-Toh, Kerstin; Postlethwait, John H.

    2016-01-01

    To connect human biology to fish biomedical models, we sequenced the genome of spotted gar (Lepisosteus oculatus), whose lineage diverged from teleosts before the teleost genome duplication (TGD). The slowly evolving gar genome conserved in content and size many entire chromosomes from bony vertebrate ancestors. Gar bridges teleosts to tetrapods by illuminating the evolution of immunity, mineralization, and development (e.g., Hox, ParaHox, and miRNA genes). Numerous conserved non-coding elements (CNEs, often cis-regulatory) undetectable in direct human-teleost comparisons become apparent using gar: functional studies uncovered conserved roles of such cryptic CNEs, facilitating annotation of sequences identified in human genome-wide association studies. Transcriptomic analyses revealed that the sum of expression domains and levels from duplicated teleost genes often approximate patterns and levels of gar genes, consistent with subfunctionalization. The gar genome provides a resource for understanding evolution after genome duplication, the origin of vertebrate genomes, and the function of human regulatory sequences. PMID:26950095

  16. The spotted gar genome illuminates vertebrate evolution and facilitates human-teleost comparisons.

    Science.gov (United States)

    Braasch, Ingo; Gehrke, Andrew R; Smith, Jeramiah J; Kawasaki, Kazuhiko; Manousaki, Tereza; Pasquier, Jeremy; Amores, Angel; Desvignes, Thomas; Batzel, Peter; Catchen, Julian; Berlin, Aaron M; Campbell, Michael S; Barrell, Daniel; Martin, Kyle J; Mulley, John F; Ravi, Vydianathan; Lee, Alison P; Nakamura, Tetsuya; Chalopin, Domitille; Fan, Shaohua; Wcisel, Dustin; Cañestro, Cristian; Sydes, Jason; Beaudry, Felix E G; Sun, Yi; Hertel, Jana; Beam, Michael J; Fasold, Mario; Ishiyama, Mikio; Johnson, Jeremy; Kehr, Steffi; Lara, Marcia; Letaw, John H; Litman, Gary W; Litman, Ronda T; Mikami, Masato; Ota, Tatsuya; Saha, Nil Ratan; Williams, Louise; Stadler, Peter F; Wang, Han; Taylor, John S; Fontenot, Quenton; Ferrara, Allyse; Searle, Stephen M J; Aken, Bronwen; Yandell, Mark; Schneider, Igor; Yoder, Jeffrey A; Volff, Jean-Nicolas; Meyer, Axel; Amemiya, Chris T; Venkatesh, Byrappa; Holland, Peter W H; Guiguen, Yann; Bobe, Julien; Shubin, Neil H; Di Palma, Federica; Alföldi, Jessica; Lindblad-Toh, Kerstin; Postlethwait, John H

    2016-04-01

    To connect human biology to fish biomedical models, we sequenced the genome of spotted gar (Lepisosteus oculatus), whose lineage diverged from teleosts before teleost genome duplication (TGD). The slowly evolving gar genome has conserved in content and size many entire chromosomes from bony vertebrate ancestors. Gar bridges teleosts to tetrapods by illuminating the evolution of immunity, mineralization and development (mediated, for example, by Hox, ParaHox and microRNA genes). Numerous conserved noncoding elements (CNEs; often cis regulatory) undetectable in direct human-teleost comparisons become apparent using gar: functional studies uncovered conserved roles for such cryptic CNEs, facilitating annotation of sequences identified in human genome-wide association studies. Transcriptomic analyses showed that the sums of expression domains and expression levels for duplicated teleost genes often approximate the patterns and levels of expression for gar genes, consistent with subfunctionalization. The gar genome provides a resource for understanding evolution after genome duplication, the origin of vertebrate genomes and the function of human regulatory sequences.

  17. Preliminary Evaluation of Moniliformin as a Potential Threat for Teleosts

    Directory of Open Access Journals (Sweden)

    Rui Goncalves

    2018-01-01

    Full Text Available Aquaculture feed manufacturers and producers increasingly recognize the importance of mycotoxins, which contaminate plant-based meals used in compound aquafeeds, and their potential to negatively impact production. Though data on the worldwide occurrence of legislated mycotoxins e.g., trichothecenes and zearalenone (ZEN are well documented, relatively little information is available regarding other mycotoxins also produced by Fusarium, notably moniliformin (MON. Given that MON is known to affect the survival, growth, skeletal formation and bone mineralization in terrestrial species, its widespread occurrence on maize and maize by-products typically used in aquaculture makes it relevant to study these parameters in teleost fish. In the present work we have tested the effect of MON exposure on survival, bone development and mineralization using zebrafish (Danio rerio as a model species and fish derived osteo-chondroprogenitor cell line for in vitro studies. Moniliformin exposure did not decrease bone mineralization in zebrafish larvae or extracellular matrix mineralization in the mineralogenic cell line VSa13. Here, the minimal in vitro cytotoxicity concentration was found to be 1000 µg L−1 MON. Incidence of deformities was also not altered by MON at the concentration tested (450 µg L−1 although larval growth was affected, as shown by a decrease in the standard length of exposed specimens at 20 days post fertilization. Survival decreased significantly in larvae exposed to MON concentrations higher than 900 μg L−1. Influence of MON on survival and growth might be relevant for aquaculture industry. As MON is a water-soluble mycotoxin, its leaching from feed is highly probable, so MON assimilation into the surrounding aqueous environment should also be considered. Tested levels in fish larvae are within the reported occurrence levels of MON in commercial feed and plant meals.

  18. Characterization of hey bHLH genes in teleost fish.

    Science.gov (United States)

    Winkler, Christoph; Elmasri, Harun; Klamt, Barbara; Volff, Jean-Nicolas; Gessler, Manfred

    2003-11-01

    Hairy-related basic helix-loop-helix (bHLH) transcription factors are targets of Delta-Notch signaling and represent essential components for a number of cell fate decisions during vertebrate embryogenesis. Hey genes encode a subfamily of hairy-related proteins that have been implicated in processes like somitogenesis, blood vessel and heart development. We have identified and characterized hey genes in three teleost fish lineages using degenerate PCR and database searches. Phylogenetic analysis of Hey proteins suggests a complex pattern of evolution with high divergence of hey2 in Takifugu rubripes (Fugu, Japanese pufferfish) and possibly loss in the related Tetraodon nigroviridis (the freshwater pufferfish). In addition, duplication of hey1 in both pufferfishes, Fugu and Tetraodon, was observed. Conversely, zebrafish (Danio rerio) has the same complement of three hey genes as known from mammals. All three hey genes show much more restricted gene expression profiles in zebrafish when compared to mouse. Importantly, while all three murine Hey genes are expressed in overlapping patterns in the presomitic mesoderm (PSM) and somites, in zebrafish only hey1 shows PSM and somite expression in a highly dynamic fashion. Therefore, while overlapping expression might account for redundancy of hey function in higher vertebrates, this is unlikely to be the case in zebrafish. In deltaD (dlD) deficient after-eight zebrafish mutants, the dynamic expression of hey1 in the PSM is impaired and completely lost in newly formed somitomeres. Overexpression of dlD on the other hand results in the ectopic expression of hey1 in the axial mesoderm. Hence, hey1 represents a target of Delta-Notch signaling dynamically expressed during somite formation in zebrafish.

  19. Exon-primed intron-crossing (EPIC markers for non-model teleost fishes

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    Riethoven Jean-Jack M

    2010-03-01

    Full Text Available Abstract Background Exon-primed intron-crossing (EPIC markers have three advantages over anonymous genomic sequences in studying evolution of natural populations. First, the universal primers designed in exon regions can be applied across a broad taxonomic range. Second, the homology of EPIC-amplified sequences can be easily determined by comparing either their exon or intron portion depending on the genetic distance between the taxa. Third, having both the exon and intron fragments could help in examining genetic variation at the intraspecific and interspecific level simultaneously, particularly helpful when studying species complex. However, the paucity of EPIC markers has hindered multilocus studies using nuclear gene sequences, particularly in teleost fishes. Results We introduce a bioinformatics pipeline for developing EPIC markers by comparing the whole genome sequences between two or more species. By applying this approach on five teleost fishes whose genomes were available in the Ensembl database http://www.ensembl.org, we identified 210 EPIC markers that have single-copy and conserved exon regions with identity greater than 85% among the five teleost fishes. We tested 12 randomly chosen EPIC markers in nine teleost species having a wide phylogenetic range. The success rate of amplifying and sequencing those markers varied from 44% to 100% in different species. We analyzed the exon sequences of the 12 EPIC markers from 13 teleosts. The resulting phylogeny contains many traditionally well-supported clades, indicating the usefulness of the exon portion of EPIC markers in reconstructing species phylogeny, in addition to the value of the intron portion of EPIC markers in interrogating the population history. Conclusions This study illustrated an effective approach to develop EPIC markers in a taxonomic group, where two or more genome sequences are available. The markers identified could be amplified across a broad taxonomic range of teleost

  20. Evolution of the duplicated intracellular lipid-binding protein genes of teleost fishes.

    Science.gov (United States)

    Venkatachalam, Ananda B; Parmar, Manoj B; Wright, Jonathan M

    2017-08-01

    Increasing organismal complexity during the evolution of life has been attributed to the duplication of genes and entire genomes. More recently, theoretical models have been proposed that postulate the fate of duplicated genes, among them the duplication-degeneration-complementation (DDC) model. In the DDC model, the common fate of a duplicated gene is lost from the genome owing to nonfunctionalization. Duplicated genes are retained in the genome either by subfunctionalization, where the functions of the ancestral gene are sub-divided between the sister duplicate genes, or by neofunctionalization, where one of the duplicate genes acquires a new function. Both processes occur either by loss or gain of regulatory elements in the promoters of duplicated genes. Here, we review the genomic organization, evolution, and transcriptional regulation of the multigene family of intracellular lipid-binding protein (iLBP) genes from teleost fishes. Teleost fishes possess many copies of iLBP genes owing to a whole genome duplication (WGD) early in the teleost fish radiation. Moreover, the retention of duplicated iLBP genes is substantially higher than the retention of all other genes duplicated in the teleost genome. The fatty acid-binding protein genes, a subfamily of the iLBP multigene family in zebrafish, are differentially regulated by peroxisome proliferator-activated receptor (PPAR) isoforms, which may account for the retention of iLBP genes in the zebrafish genome by the process of subfunctionalization of cis-acting regulatory elements in iLBP gene promoters.

  1. The utricular otoliths, lapilli, of teleosts: their morphology and relevance for species identification and systematics studies

    Directory of Open Access Journals (Sweden)

    Carlos A. Assis

    2005-06-01

    Full Text Available The present study describes the general morphology of the utricular otoliths, lapilli, of teleost fishes, proposes a terminology for their parts, identifies their two major morphological types, provides some examples of their use in species identification, and discusses their usefulness in studies of fish phylogeny and systematics.

  2. Osmoregulation and epithelial water transport: lessons from the intestine of marine teleost fish.

    Science.gov (United States)

    Whittamore, Jonathan M

    2012-01-01

    For teleost fish living in seawater, drinking the surrounding medium is necessary to avoid dehydration. This is a key component of their osmoregulatory strategy presenting the challenge of excreting excess salts while achieving a net retention of water. The intestine has an established role in osmoregulation, and its ability to effectively absorb fluid is crucial to compensating for water losses to the hyperosmotic environment. Despite this, the potential for the teleost intestine to serve as a comparative model for detailed, integrative experimental studies on epithelial water transport has so far gone largely untapped. The following review aims to present an assessment of the teleost intestine as a fluid-transporting epithelium. Beginning with a brief overview of marine teleost osmoregulation, emphasis shifts to the processing of ingested seawater by the gastrointestinal tract and the characteristics of intestinal ion and fluid transport. Particular attention is given to acid-base transfers by the intestine, specifically bicarbonate secretion, which creates the distinctly alkaline gut fluids responsible for the formation of solid calcium carbonate precipitates. The respective contributions of these unique features to intestinal fluid absorption, alongside other recognised ion transport processes, are then subsequently considered within the wider context of the classic physiological problem of epithelial water transport.

  3. Linking species habitat and past palaeoclimatic events to evolution of the teleost innate immune system.

    Science.gov (United States)

    Solbakken, Monica Hongrø; Voje, Kjetil Lysne; Jakobsen, Kjetill Sigurd; Jentoft, Sissel

    2017-04-26

    Host-intrinsic factors as well as environmental changes are known to be strong evolutionary drivers defining the genetic foundation of immunity. Using a novel set of teleost genomes and a time-calibrated phylogeny, we here investigate the family of Toll-like receptor ( TLR ) genes and address the underlying evolutionary processes shaping the diversity of the first-line defence. Our findings reveal remarkable flexibility within the evolutionary design of teleost innate immunity characterized by prominent TLR gene losses and expansions. In the order of Gadiformes, expansions correlate with the loss of major histocompatibility complex class II ( MHCII ) and diversifying selection analyses support that this has fostered new immunological innovations in TLR s within this lineage. In teleosts overall, TLRs expansions correlate with species latitudinal distributions and maximum depth. By contrast, lineage-specific gene losses overlap with well-described changes in palaeoclimate (global ocean anoxia) and past Atlantic Ocean geography. In conclusion, we suggest that the evolvability of the teleost immune system has most likely played a prominent role in the survival and successful radiation of this lineage. © 2017 The Authors.

  4. Structural and functional diversification in the teleost S100 family of calcium-binding proteins

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    Korsching Sigrun I

    2008-02-01

    Full Text Available Abstract Background Among the EF-Hand calcium-binding proteins the subgroup of S100 proteins constitute a large family with numerous and diverse functions in calcium-mediated signaling. The evolutionary origin of this family is still uncertain and most studies have examined mammalian family members. Results We have performed an extensive search in several teleost genomes to establish the s100 gene family in fish. We report that the teleost S100 repertoire comprises fourteen different subfamilies which show remarkable similarity across six divergent teleost species. Individual species feature distinctive subsets of thirteen to fourteen genes that result from local gene duplications and gene losses. Eight of the fourteen S100 subfamilies are unique for teleosts, while six are shared with mammalian species and three of those even with cartilaginous fish. Several S100 family members are found in jawless fish already, but none of them are clear orthologs of cartilaginous or bony fish s100 genes. All teleost s100 genes show the expected structural features and are subject to strong negative selection. Many aspects of the genomic arrangement and location of mammalian s100 genes are retained in the teleost s100 gene family, including a completely conserved intron/exon border between the two EF hands. Zebrafish s100 genes exhibit highly specific and characteristic expression patterns, showing both redundancy and divergence in their cellular expression. In larval tissue expression is often restricted to specific cell types like keratinocytes, hair cells, ionocytes and olfactory receptor neurons as demonstrated by in situ hybridization. Conclusion The origin of the S100 family predates at least the segregation of jawed from jawless fish and some extant family members predate the divergence of bony from cartilaginous fish. Despite a complex pattern of gene gains and losses the total repertoire size is remarkably constant between species. On the expression

  5. Relaxin gene family in teleosts: phylogeny, syntenic mapping, selective constraint, andexpression analysis

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    Glen Peter

    2009-12-01

    Full Text Available Abstract Background In recent years, the relaxin family of signaling molecules has been shown to play diverse roles in mammalian physiology, but little is known about its diversity or physiology in teleosts, an infraclass of the bony fishes comprising ~ 50% of all extant vertebrates. In this paper, 32 relaxin family sequences were obtained by searching genomic and cDNA databases from eight teleost species; phylogenetic, molecular evolutionary, and syntenic data analyses were conducted to understand the relationship and differential patterns of evolution of relaxin family genes in teleosts compared with mammals. Additionally, real-time quantitative PCR was used to confirm and assess the tissues of expression of five relaxin family genes in Danio rerio and in situ hybridization used to assess the site-specific expression of the insulin 3-like gene in D. rerio testis. Results Up to six relaxin family genes were identified in each teleost species. Comparative syntenic mapping revealed that fish possess two paralogous copies of human RLN3, which we call rln3a and rln3b, an orthologue of human RLN2, rln, two paralogous copies of human INSL5, insl5a and insl5b, and an orthologue of human INSL3, insl3. Molecular evolutionary analyses indicated that: rln3a, rln3b and rln are under strong evolutionary constraint, that insl3 has been subject to moderate rates of sequence evolution with two amino acids in insl3/INSL3 showing evidence of positively selection, and that insl5b exhibits a higher rate of sequence evolution than its paralogue insl5a suggesting that it may have been neo-functionalized after the teleost whole genome duplication. Quantitative PCR analyses in D. rerio indicated that rln3a and rln3b are expressed in brain, insl3 is highly expressed in gonads, and that there was low expression of both insl5 genes in adult zebrafish. Finally, in situ hybridization of insl3 in D. rerio testes showed highly specific hybridization to interstitial Leydig

  6. Ultrastructural and biochemical analysis of epidermal xanthophores and dermal chromatophores of the teleost Sparus aurata.

    Science.gov (United States)

    Ferrer, C; Solano, F; Zuasti, A

    1999-04-01

    We have studied the pigmentary system of the teleost Sparus aurata skin by electron microscopy and chromatographic analysis. Under electron microscopy, we found the dermis to contain the three major types of recognized chromatophores: melanophores, xanthophores and iridophores. Melanophores were more abundant in the dorsal region, whereas the iridophores were more abundant in the ventral region. The most important discovery was that of epidermal xanthophores. Epidermal xanthophores were the only chromatophores in the epidermis, something only found in S aurata and in a teleost species living in the Antartic sea. In contrast, the biochemical analysis did not establish any special characteristics: we found pteridine and flavin pigments located mostly in the pigmented dorsal region. Riboflavin and pterin were two of the most abundant coloured pigment types, but other colourless pigments such as xanthopterin and isoxanthopterin were also detected.

  7. Salinity Regulates Claudin mRNA and Protein Expression in the Teleost Gill

    DEFF Research Database (Denmark)

    Tipsmark, Christian K; Baltzegar, David A; Ozden, Ozkan

    2008-01-01

    The teleost gill carries out NaCl uptake in fresh water (FW) and NaCl excretion in seawater (SW). This transformation with salinity requires close regulation of ion transporter capacity and epithelial permeability. This study investigates the regulation of tight junctional claudins during salinity...... was localized deep in the FW gill filament, whereas staining was found apically in SW gill. Claudin 4-like proteins are localized predominantly in the filament outer epithelial layer and staining appears more intense in gill of FW versus SW fish. Additionally, tilapia claudin 28a and 30 genes were characterized......, and mRNA expression was found to increase during FW acclimation. These studies are the first to detect putative claudin proteins in teleosts and show their localization and regulation with salinity in gill epithelium. The data indicate that claudins may be important in permeability changes associated...

  8. Some comments upon acid-base balance in teleost fishes and its relationship to environmental temperature

    Energy Technology Data Exchange (ETDEWEB)

    Houston, A.H.

    1971-01-01

    It has been hypothesized that acid-base regulation in mammalian species is directed toward stabilization of body fluid pH, whereas among the poikilotherms control centers upon the maintenance of relative alkalinity. Consequently, given the known relationship between temperature and the dissociation constant of water reductions in mammalian body temperature should be accompanied by decreases in the OH/sup -//H/sup +/ ratio while, under similar circumstances, the pH of the poikilothermic tetrapods, extension of the concept of relative alkalinity regulation to teleost fishes is not wholly consistent with the data presently available. Recorded blood and plasma pH values for teleost fishes are generally below those reported for amphibians and reptiles, tending to fall within or below the levels observed in mammals under comparable thermal conditions. Moreover, they seemingly display little tendency to vary in an inverse fashion wth temperature.

  9. Detection, Properties, and Frequency of Local Calcium Release from the Sarcoplasmic Reticulum in Teleost Cardiomyocytes

    OpenAIRE

    Llach, Anna; Molina, Cristina E.; Alvarez Lacalle, Enrique; Tort, Lluis; Benítez, Raul; Hove, Leif

    2011-01-01

    Calcium release from the sarcoplasmic reticulum (SR) plays a central role in the regulation of cardiac contraction and rhythm in mammals and humans but its role is controversial in teleosts. Since the zebrafish is an emerging model for studies of cardiovascular function and regeneration we here sought to determine if basic features of SR calcium release are phylogenetically conserved. Confocal calcium imaging was used to detect spontaneous calcium release (calcium sparks and waves) from...

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

    Science.gov (United States)

    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.

  11. Prolactin and teleost ionocytes: new insights into cellular and molecular targets of prolactin in vertebrate epithelia

    Science.gov (United States)

    Breves, Jason P.; McCormick, Stephen D.; Karlstrom, Rolf O.

    2014-01-01

    The peptide hormone prolactin is a functionally versatile hormone produced by the vertebrate pituitary. Comparative studies over the last six decades have revealed that a conserved function for prolactin across vertebrates is the regulation of ion and water transport in a variety of tissues including those responsible for whole-organism ion homeostasis. In teleost fishes, prolactin was identified as the “freshwater-adapting hormone”, promoting ion-conserving and water-secreting processes by acting on the gill, kidney, gut and urinary bladder. In mammals, prolactin is known to regulate renal, intestinal, mammary and amniotic epithelia, with dysfunction linked to hypogonadism, infertility, and metabolic disorders. Until recently, our understanding of the cellular mechanisms of prolactin action in fishes has been hampered by a paucity of molecular tools to define and study ionocytes, specialized cells that control active ion transport across branchial and epidermal epithelia. Here we review work in teleost models indicating that prolactin regulates ion balance through action on ion transporters, tight-junction proteins, and water channels in ionocytes, and discuss recent advances in our understanding of ionocyte function in the genetically and embryonically accessible zebrafish (Danio rerio). Given the high degree of evolutionary conservation in endocrine and osmoregulatory systems, these studies in teleost models are contributing novel mechanistic insight into how prolactin participates in the development, function, and dysfunction of osmoregulatory systems across the vertebrate lineage.

  12. Molecular and functional characterization of a fads2 orthologue in the Amazonian teleost, Arapaima gigas.

    Science.gov (United States)

    Lopes-Marques, Mónica; Ozório, Rodrigo; Amaral, Ricardo; Tocher, Douglas R; Monroig, Óscar; Castro, L Filipe C

    2017-01-01

    The Brazilian teleost Arapaima gigas is an iconic species of the Amazon. In recent years a significant effort has been put into the farming of arapaima to mitigate overfishing threats. However, little is known regarding the nutritional requirements of A. gigas in particular those for essential fatty acids including the long-chain polyunsaturated fatty acids (LC-PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The ability to biosynthesize LC-PUFA is dependent upon the gene repertoire of fatty acyl desaturases (Fads) and elongases (Elovl), as well as their fatty acid specificities. In the present study we characterized both molecularly and functionally an orthologue of the desaturase fatty acid desaturase 2 (fads2) from A. gigas. The isolated sequence displayed the typical desaturase features, a cytochrome b 5 -domain with the heme-binding motif, two transmembrane domains and three histidine-rich regions. Functional characterization of A. gigas fads2 showed that, similar to other teleosts, the A. gigas fads2 exhibited a predominant Δ6 activity complemented with some capacity for Δ8 desaturation. Given that A. gigas belongs to one of the oldest teleostei lineages, the Osteoglossomorpha, these findings offer a significant insight into the evolution LC-PUFA biosynthesis in teleosts. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. A teleost CD46 is involved in the regulation of complement activation and pathogen infection.

    Science.gov (United States)

    Li, Mo-Fei; Sui, Zhi-Hai; Sun, Li

    2017-11-03

    In mammals, CD46 is involved in the inactivation of complement by factor I (FI). In teleost, study on the function of CD46 is very limited. In this study, we examined the immunological property of a CD46 molecule (CsCD46) from tongue sole, a teleost species with important economic value. We found that recombinant CsCD46 (rCsCD46) interacted with FI and inhibited complement activation in an FI-dependent manner. rCsCD46 also interacted with bacterial pathogens via a different mechanism to that responsible for the FI interaction, involving different rCsCD46 sites. Cellular study showed that CsCD46 was expressed on peripheral blood leukocytes (PBL) and protected the cells against the killing effect of complement. When the CsCD46 on PBL was blocked by antibody before incubation of the cells with bacterial pathogens, cellular infection was significantly reduced. Consistently, when tongue sole were infected with bacterial pathogens in the presence of rCsCD46, tissue dissemination and survival of the pathogens were significantly inhibited. These results provide the first evidence to indicate that CD46 in teleosts negatively regulates complement activation via FI and protects host cells from complement-induced damage, and that CD46 is required for optimal bacterial infection probably by serving as a receptor for the bacteria.

  14. Teleost Fish-Specific Preferential Retention of Pigmentation Gene-Containing Families After Whole Genome Duplications in Vertebrates

    Science.gov (United States)

    Lorin, Thibault; Brunet, Frédéric G.; Laudet, Vincent; Volff, Jean-Nicolas

    2018-01-01

    Vertebrate pigmentation is a highly diverse trait mainly determined by neural crest cell derivatives. It has been suggested that two rounds (1R/2R) of whole-genome duplications (WGDs) at the basis of vertebrates allowed changes in gene regulation associated with neural crest evolution. Subsequently, the teleost fish lineage experienced other WGDs, including the teleost-specific Ts3R before teleost radiation and the more recent Ss4R at the basis of salmonids. As the teleost lineage harbors the highest number of pigment cell types and pigmentation diversity in vertebrates, WGDs might have contributed to the evolution and diversification of the pigmentation gene repertoire in teleosts. We have compared the impact of the basal vertebrate 1R/2R duplications with that of the teleost-specific Ts3R and salmonid-specific Ss4R WGDs on 181 gene families containing genes involved in pigmentation. We show that pigmentation genes (PGs) have been globally more frequently retained as duplicates than other genes after Ts3R and Ss4R but not after the early 1R/2R. This is also true for non-pigmentary paralogs of PGs, suggesting that the function in pigmentation is not the sole key driver of gene retention after WGDs. On the long-term, specific categories of PGs have been repeatedly preferentially retained after ancient 1R/2R and Ts3R WGDs, possibly linked to the molecular nature of their proteins (e.g., DNA binding transcriptional regulators) and their central position in protein-protein interaction networks. Taken together, our results support a major role of WGDs in the diversification of the pigmentation gene repertoire in the teleost lineage, with a possible link with the diversity of pigment cell lineages observed in these animals compared to other vertebrates. PMID:29599177

  15. Corticosteroids stimulate the amphibious behavior in mudskipper: potential role of mineralocorticoid receptors in teleost fish.

    Science.gov (United States)

    Sakamoto, Tatsuya; Mori, Chie; Minami, Shogo; Takahashi, Hideya; Abe, Tsukasa; Ojima, Daisuke; Ogoshi, Maho; Sakamoto, Hirotaka

    2011-10-24

    It has long been held that cortisol, a glucocorticoid in many vertebrates, carries out both glucocorticoid and mineralocorticoid actions in teleost fish. However, 11-deoxycorticosterone (DOC) has been identified as a specific endogenous ligand for the teleostean mineralocorticoid receptor (MR). Furthermore, the expressions of MR mRNA are modest in the osmoregulatory organs, but considerably higher in the brain of most teleosts. These recent findings suggest that the mineralocorticoid system (DOC/MR) may carry out some behavioral functions in fish. To test this possibility, we examined the effects of cortisol and DOC administration in the amphibious behavior in mudskipper (Periophthalmus modestus) in vivo. It was found that mudskippers remained in the water for an increased period of time when they were immersed into 5 μM DOC or cortisol for 8h. Additionally, an exposure to 25 μM DOC for 4 to 8 h caused a decreased migratory frequency of mudskippers to the water, reflected a tendency to remain in the water. It was further observed that after 8 h of intracerebroventricular (ICV) injection with 0.3 pmol DOC or cortisol the staying period in the water increased in fish. The migratory frequency was decreased after ICV DOC injection which indicated that fishes stayed in the water. Concurrent ICV injections of cortisol with RU486 [a specific glucocorticoid-receptor (GR) antagonist] inhibited only the partial effects of cortisol. Together with no changes in the plasma DOC concentrations under terrestrial conditions, these results indicate the involvement of brain MRs as cortisol receptors in the preference for an aquatic habitat of mudskippers. Although the role of GR signaling cannot be excluded in the aquatic preference, our data further suggest that the MR may play an important role in the brain dependent behaviors of teleost fish. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. The nonlinear flexural response of a whole teleost fish: Contribution of scales and skin.

    Science.gov (United States)

    Szewciw, Lawrence; Zhu, Deju; Barthelat, Francois

    2017-12-01

    The scaled skin of fish is an intricate system that provides mechanical protection against hard and sharp puncture, while maintaining the high flexural compliance required for unhindered locomotion. This unusual combination of local hardness and global compliance makes fish skin an interesting model for bioinspired protective systems. In this work we investigate the flexural response of whole teleost fish, and how scales may affect global flexural stiffness. A bending moment is imposed on the entire body of a striped bass (Morone saxatilis). Imaging is used to measure local curvature, to generate moment-curvature curves as function of position along the entire axis of the fish. We find that the flexural stiffness is the highest in the thick middle portion of the fish, and lowest in the caudal and rostral ends. The flexural response is nonlinear, with an initial soft response followed by significant stiffening at larger flexural deformations. Low flexural stiffness at low curvatures promotes efficient swimming, while higher stiffness at high curvatures enables a possible tendon effect, where the mechanical energy at the end of a stroke is stored in the form of strain energy in the fish skin. To assess the contribution of the scales to stiffening we performed flexural tests with and without scales, following a careful protocol to take in account tissue degradation and the effects of temperature. Our findings suggest that scales do not substantially increase the whole body flexural stiffness of teleost fish over ranges of deformations which are typical of swimming and maneuvering. Teleost scales are thin and relatively flexible, so they can accommodate large flexural deformations. This finding is in contrast to the bulkier ganoid scales which were shown in previous reports to have a profound impact of global flexural deformations and swimming in fish like gar or Polypterus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Rapid genome reshaping by multiple-gene loss after whole-genome duplication in teleost fish suggested by mathematical modeling

    Science.gov (United States)

    Sato, Yukuto; Tsukamoto, Katsumi; Nishida, Mutsumi

    2015-01-01

    Whole-genome duplication (WGD) is believed to be a significant source of major evolutionary innovation. Redundant genes resulting from WGD are thought to be lost or acquire new functions. However, the rates of gene loss and thus temporal process of genome reshaping after WGD remain unclear. The WGD shared by all teleost fish, one-half of all jawed vertebrates, was more recent than the two ancient WGDs that occurred before the origin of jawed vertebrates, and thus lends itself to analysis of gene loss and genome reshaping. Using a newly developed orthology identification pipeline, we inferred the post–teleost-specific WGD evolutionary histories of 6,892 protein-coding genes from nine phylogenetically representative teleost genomes on a time-calibrated tree. We found that rapid gene loss did occur in the first 60 My, with a loss of more than 70–80% of duplicated genes, and produced similar genomic gene arrangements within teleosts in that relatively short time. Mathematical modeling suggests that rapid gene loss occurred mainly by events involving simultaneous loss of multiple genes. We found that the subsequent 250 My were characterized by slow and steady loss of individual genes. Our pipeline also identified about 1,100 shared single-copy genes that are inferred to have become singletons before the divergence of clupeocephalan teleosts. Therefore, our comparative genome analysis suggests that rapid gene loss just after the WGD reshaped teleost genomes before the major divergence, and provides a useful set of marker genes for future phylogenetic analysis. PMID:26578810

  18. Conservation of the photoperiodic neuroendocrine axis among vertebrates: evidence from the teleost fish, Gasterosteus aculeatus.

    Science.gov (United States)

    O'Brien, Conor S; Bourdo, Ryan; Bradshaw, William E; Holzapfel, Christina M; Cresko, William A

    2012-08-01

    Photoperiod, or length of day, has a predictable annual cycle, making it an important cue for the timing of seasonal behavior and development in many organisms. Photoperiod is widely used among temperate and polar animals to regulate the timing of sexual maturation. The proper sensing and interpretation of photoperiod can be tightly tied to an organism's overall fitness. In photoperiodic mammals and birds the thyroid hormone pathway initiates sexual maturation, but the degree to which this pathway is conserved across other vertebrates is not well known. We use the threespine stickleback Gasterosteus aculeatus, as a representative teleost to quantify the photoperiodic response of key genes in the thyroid hormone pathway under controlled laboratory conditions. We find that the photoperiodic responses of the hormones are largely consistent amongst multiple populations, although differences suggest physiological adaptation to various climates. We conclude that the thyroid hormone pathway initiates sexual maturation in response to photoperiod in G. aculeatus, and our results show that more components of this pathway are conserved among mammals, birds, and teleost fish than was previously known. However, additional endocrinology, cell biology and molecular research will be required to define precisely which aspects of the pathway are conserved across vertebrates. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Corticosteroid receptor expression in a teleost fish that displays alternative male reproductive tactics.

    Science.gov (United States)

    Arterbery, Adam S; Deitcher, David L; Bass, Andrew H

    2010-01-01

    Corticosteroid signaling mechanisms mediate a wide range of adaptive physiological responses, including those essential to reproduction. Here, we investigated the presence and relative abundance of corticosteroid receptors during the breeding season in the plainfin midshipman fish (Porichthys notatus), a species that has two male reproductive morphs. Only type I "singing" males acoustically court females and aggressively defend a nest site, whereas type II "sneaker" males steal fertilizations from nesting type I males. Cloning and sequencing first identified glucocorticoid (GR) and mineralocorticoid (MR) receptors in midshipman that exhibited high sequence identity with other vertebrate GRs and MRs. Absolute-quantitative real-time PCR then revealed higher levels of GR in the central nervous system (CNS) of type II males than type I males and females, while GR levels in the sound-producing, vocal muscle and the liver were higher in type I males than type II males and females. MR expression was also greater in the CNS of type II males than type I males or females, but the differences were more modest in magnitude. Lastly, plasma levels of cortisol, the main glucocorticoid in teleosts, were 2- to 3-fold greater in type II males compared to type I males. Together, the results suggest a link between corticosteroid regulation and physiological and behavioral variation in a teleost fish that displays male alternative reproductive tactics.

  20. Immunocytochemical identification of adenohypophyseal cells in the pirarucu (Arapaima gigas), an Amazonian basal teleost.

    Science.gov (United States)

    Borella, M I; Venturieri, R; Mancera, J M

    2009-03-01

    The adenohypophysis (AH) of juvenile pirarucu (Arapaima gigas), a representative species of the Osteoglossomorpha (bonytongue fishes, one of the oldest living groups of the teleosts), was studied using histochemical and immunocytochemical methods. The AH is comprised of the pars distalis (PD), without a clear distinction between rostral pars distalis (RPD) and proximal pars distalis (PPD), and the pars intermedia (PI). The neurohypophysis (NH) is positioned on top of the PD and penetrates and branches into the PI. In the most rostral dorsal portion of the PD, adrenocorticotropic cells and fusiform gonadotropic cells were found. In the central PD, scarce prolactin-producing cells and growth-hormone-producing cells were located mainly in the dorsal part, whereas round gonadotropic cells were abundant in the ventral portion of this region. Human thyrotropin immunoreactive cells were not found in the entire AH. In the PI, melanotropic, some adrenocorticotropic, and somatolactin-producing cells were located intermingled surrounding the neurohypophyseal branches. Our results showed that the A. gigas pituitary has some basal characteristics between the ancient Actinopterygii and the more derived teleosts.

  1. The hypothalamus-pituitary-thyroid axis in teleosts and amphibians: Endocrine disruption and its consequences to natural populations

    Science.gov (United States)

    Carr, J.A.; Patino, R.

    2011-01-01

    Teleosts and pond-breeding amphibians may be exposed to a wide variety of anthropogenic, waterborne contaminants that affect the hypothalamus-pituitary-thyroid (HPT) axis. Because thyroid hormone is required for their normal development and reproduction, the potential impact of HPT-disrupting contaminants on natural teleost and amphibian populations raises special concern. There is laboratory evidence indicating that persistent organic pollutants, heavy metals, pharmaceutical and personal care products, agricultural chemicals, and aerospace products may alter HPT activity, development, and reproduction in teleosts and amphibians. However, at present there is no evidence to clearly link contaminant-induced HPT alterations to impairments in teleost or amphibian population health in the field. Also, with the exception of perchlorate for which laboratory studies have shown a direct link between HPT disruption and adverse impacts on development and reproductive physiology, little is known about if or how other HPT-disrupting contaminants affect organismal performance. Future field studies should focus on establishing temporal associations between the presence of HPT-disrupting chemicals, the occurrence of HPT alterations, and adverse effects on development and reproduction in natural populations; as well as determining how complex mixtures of HPT contaminants affect organismal and population health. ?? 2010 Elsevier Inc.

  2. The hypothalamus–pituitary–thyroid axis in teleosts and amphibians: Endocrine disruption and its consequences to natural populations

    Science.gov (United States)

    Carr, J.A.; Patino, Reynaldo

    2011-01-01

    Teleosts and pond-breeding amphibians may be exposed to a wide variety of anthropogenic, waterborne contaminants that affect the hypothalamus-pituitary-thyroid (HPT) axis. Because thyroid hormone is required for their normal development and reproduction, the potential impact of HPT-disrupting contaminants on natural teleost and amphibian populations raises special concern. There is laboratory evidence indicating that persistent organic pollutants, heavy metals, pharmaceutical and personal care products, agricultural chemicals, and aerospace products may alter HPT activity, development, and reproduction in teleosts and amphibians. However, at present there is no evidence to clearly link contaminant-induced HPT alterations to impairments in teleost or amphibian population health in the field. Also, with the exception of perchlorate for which laboratory studies have shown a direct link between HPT disruption and adverse impacts on development and reproductive physiology, little is known about if or how other HPT-disrupting contaminants affect organismal performance. Future field studies should focus on establishing temporal associations between the presence of HPT-disrupting chemicals, the occurrence of HPT alterations, and adverse effects on development and reproduction in natural populations; as well as determining how complex mixtures of HPT contaminants affect organismal and population health.

  3. The cytochemical demonstration of catalase and D-amino acid oxidase in the microbodies of teleost kidney cells

    NARCIS (Netherlands)

    Veenhuis, M.; Wendelaar Bonga, S.D.

    1977-01-01

    The distribution of catalase and D-amino acid oxidase, marker enzymes for peroxisomes, was determined cytochemically in the kidney tubules of an euryhaline teleost, the three-spined stickleback. Catalase activity was localized with the diaminobenzidine technique. The presence of D-amino acid oxidase

  4. Duplication of the dystroglycan gene in most branches of teleost fish

    Directory of Open Access Journals (Sweden)

    Giardina Bruno

    2007-05-01

    Full Text Available Abstract Background The dystroglycan (DG complex is a major non-integrin cell adhesion system whose multiple biological roles involve, among others, skeletal muscle stability, embryonic development and synapse maturation. DG is composed of two subunits: α-DG, extracellular and highly glycosylated, and the transmembrane β-DG, linking the cytoskeleton to the surrounding basement membrane in a wide variety of tissues. A single copy of the DG gene (DAG1 has been identified so far in humans and other mammals, encoding for a precursor protein which is post-translationally cleaved to liberate the two DG subunits. Similarly, D. rerio (zebrafish seems to have a single copy of DAG1, whose removal was shown to cause a severe dystrophic phenotype in adult animals, although it is known that during evolution, due to a whole genome duplication (WGD event, many teleost fish acquired multiple copies of several genes (paralogues. Results Data mining of pufferfish (T. nigroviridis and T. rubripes and other teleost fish (O. latipes and G. aculeatus available nucleotide sequences revealed the presence of two functional paralogous DG sequences. RT-PCR analysis proved that both the DG sequences are transcribed in T. nigroviridis. One of the two DG sequences harbours an additional mini-intronic sequence, 137 bp long, interrupting the uncomplicated exon-intron-exon pattern displayed by DAG1 in mammals and D. rerio. A similar scenario emerged also in D. labrax (sea bass, from whose genome we have cloned and sequenced a new DG sequence that also harbours a shorter additional intronic sequence of 116 bp. Western blot analysis confirmed the presence of DG protein products in all the species analysed including two teleost Antarctic species (T. bernacchii and C. hamatus. Conclusion Our evolutionary analysis has shown that the whole-genome duplication event in the Class Actinopterygii (ray-finned fish involved also DAG1. We unravelled new important molecular genetic details

  5. The calcium channel β2 (CACNB2 subunit repertoire in teleosts

    Directory of Open Access Journals (Sweden)

    Mueller Rachel

    2008-04-01

    Full Text Available Abstract Background Cardiomyocyte contraction is initiated by influx of extracellular calcium through voltage-gated calcium channels. These oligomeric channels utilize auxiliary β subunits to chaperone the pore-forming α subunit to the plasma membrane, and to modulate channel electrophysiology 1. Several β subunit family members are detected by RT-PCR in the embryonic heart. Null mutations in mouse β2, but not in the other three β family members, are embryonic lethal at E10.5 due to defects in cardiac contractility 2. However, a drawback of the mouse model is that embryonic heart rhythm is difficult to study in live embryos due to their intra-uterine development. Moreover, phenotypes may be obscured by secondary effects of hypoxia. As a first step towards developing a model for contributions of β subunits to the onset of embryonic heart rhythm, we characterized the structure and expression of β2 subunits in zebrafish and other teleosts. Results Cloning of two zebrafish β2 subunit genes (β2.1 and β2.2 indicated they are membrane-associated guanylate kinase (MAGUK-family genes. Zebrafish β2 genes show high conservation with mammals within the SH3 and guanylate kinase domains that comprise the "core" of MAGUK proteins, but β2.2 is much more divergent in sequence than β2.1. Alternative splicing occurs at the N-terminus and within the internal HOOK domain. In both β2 genes, alternative short ATG-containing first exons are separated by some of the largest introns in the genome, suggesting that individual transcript variants could be subject to independent cis-regulatory control. In the Tetraodon nigrovidis and Fugu rubripes genomes, we identified single β2 subunit gene loci. Comparative analysis of the teleost and human β2 loci indicates that the short 5' exon sequences are highly conserved. A subset of 5' exons appear to be unique to teleost genomes, while others are shared with mammals. Alternative splicing is temporally and

  6. Rhythmicity and plasticity of digestive physiology in a euryhaline teleost fish, permit (Trachinotus falcatus)

    DEFF Research Database (Denmark)

    Lazado, Carlo Cabacang; Pedersen, Per Bovbjerg; Nguyen, Huy Quang

    2017-01-01

    Digestive physiology is considered to be under circadian control, but there is little evidence in teleost fish. The present study explored the rhythmicity and plasticity to feeding schedules of enzymatic digestion in a candidate aquaculture fish, the permit (Trachinotus falcatus). The first...... experiment identified the rhythms of digestive factors throughout the light-dark (LD) cycle. Gastric luminal pH and pepsin activity showed significant daily variation albeit not rhythmic. These dynamic changes were likewise observed in several digestive enzymes, in which the activities of intestinal protease......, chymotrypsin and lipase exhibited significant daily rhythms. In the second experiment, the existence of feed anticipatory activity in the digestive factors was investigated by subjecting the fish to either periodic or random feeding. Anticipatory gastric acidification prior to feeding was identified...

  7. Unique hepatic cytosolic arginase evolved independently in ureogenic freshwater air-breathing teleost, Heteropneustes fossilis.

    Directory of Open Access Journals (Sweden)

    Shilpee Srivastava

    Full Text Available Hepatic cytosolic arginase (ARG I, an enzyme of the urea cycle operating in the liver of ureotelic animals, is reported to be present in an ammoniotelic freshwater air-breathing teleost, Heteropneustes fossilis which has ureogenic potential. Antibodies available against mammalian ARG I showed no cross reactivity with the H. fossilis ARG I. We purified unique ARG I from H. fossilis liver. Purified ARG I is a homotrimer with molecular mass 75 kDa and subunit molecular mass of 24 kDa. The pI value of the enzyme was 8.5. It showed maximum activity at pH 10.5 and 55°C. The Km of purified enzyme for L-arginine was 2.65±0.39 mM. L-ornithine and N(ω-hydroxy-L-arginine showed inhibition of the ARG I activity, with Ki values 0.52±0.02mM and 0.08±0.006mM, respectively. Antibody raised against the purified fish liver ARG I showed exclusive specificity, and has no cross reactivity against fish liver ARG II and mammalian liver ARG I and ARG II. We found another isoform of arginase bound to the outer membrane of the mitochondria which was released by 150-200 mM KCl in the extraction medium. This isoform was immunologically different from the soluble cytosolic and mitochondrial arginase. The results of present study support that hepatic cytosolic arginase evolved in this ureogenic freshwater teleost, H. fossilis. Phylogenetic analysis confirms an independent evolution event that occurred much after the evolution of the cytosolic arginase of ureotelic vertebrates.

  8. An electron microscopic investigation into the possible source of new muscle fibres in teleost fish.

    Science.gov (United States)

    Stoiber, W; Sänger, A M

    1996-12-01

    This study is based on transmission electron microscopic (TEM) investigations of deep (fast, 'white') teleost fish muscle proliferation in early developmental stages of three European cyprinid species and the rainbow trout. Our fine structural findings provide evidence that early myotomal growth in these animals may utilize different mechanisms that are activated in close succession during early life history. First, initial enlargement of the deep muscle bulk in the embryo seems to be due to hypertrophy of the somite-cell derived stock of muscle fibres. Second, we suggest that deep muscle growth becomes additionally powered by attachment of presumptive myogenic cells that originate from and proliferate within the adjacent mesenchymal tissue lining. Third, mesenchyme-derived muscle cell precursors are thought to enter the myotomes via the myosepta. After migration between the pre-established muscle fibres these cells may function as myosatellite cells, thus at least partly providing the stem cell population for subsequent rapid hyperplastic growth. Finally, there is evidence that presumptive deep muscle satellite cells also proliferate by mitotic division in situ. A similar process of myogenic cell migration and proliferation may foster intermediate fibre differentiation. The model of myogenic cell migration is discussed in view of in vitro and in vivo data on satellite cell migratory power and with respect to temperature-induced and species dependent differences. As for the latter, our results indicate that patterns of muscle differentiation may diverge between a fast growing salmonid species and a moderately growing cyprinid species of similar final size. The model is compatible with the well-established idea that teleost muscle growth may rely on different subclasses of myosatellite cells.

  9. Adrenocortical and adrenomedullary homologs in eight species of adult and developing teleosts: morphology, histology, and immunohistochemistry.

    Science.gov (United States)

    Grassi Milano, E; Basari, F; Chimenti, C

    1997-12-01

    Morphology, histology, and immunohistochemistry of the adrenocortical and adrenomedullary homologs (adrenal glands) of the following developing and adult teleosts were examined: Salmoniformes-Oncorhynchus mykiss (rainbow trout), Salmo trutta fario (brown trout), Coregonus lavaretus (white fish); Cyprinodontiformes-Gambusia affinis (mosquito fish). Perciformes-Dicentrarchus labrax (sea bass), Sparus aurata (sea bream), Diplodus sargus (white bream), Oblada melanura (saddled bream). The anatomical relationships of the gland with the renal system and venous vessels were also noted. In adults of all species steroidogenic and catecholaminergic chromaffin cells were found in the head kidney, which is pronephric in origin and subsequently transformed into a hematopoietic lymphatic organ. In Perciformes, chromaffin cells are distributed around the anterior and posterior cardinal veins and ducts of Cuvier; in Salmoniformes, around the posterior cardinal veins and in the hematopoietic tissue; and in G. affinis, around the ducts of Cuvier and posterior cardinal veins, while a few are visible also around the sinus venosus. In Perciformes and Salmoniformes, numerous chromaffin cells are also present in the posterior kidney, derived from the opisthonephros, in contact with the caudal vein. Steroidogenic cells are always confined to the head kidney. During development chromaffin and steroidogenic cells appear early after hatching in the pronephric kidney, at the level of the ducts of Cuvier and of the cephalic part of the posterior cardinal veins. Later, chromaffin cells in Perciformes reach the anterior cardinal veins, and subsequently, in both Perciformes and Salmoniformes, they reach the developing posterior kidney. Their localization along the posterior kidney is still in progress about 4 months after hatching and is completed about a year after hatching. These findings support the concept that the structure of the adrenal gland in teleosts is intermediate between that of the

  10. Effects of various ecological factors on radiostrontium uptake in two euryhaline teleosts: Mugil auratus Risso and Pleuronectes platessa L

    International Nuclear Information System (INIS)

    Amiard, J.-C.

    1975-11-01

    The effects of various ecological, biotic and abiotic factors (age, species, salinity, temperature, sediment, calcium overload, food) on the accumulation of 85 Sr were studied in two euryhaline Teleosts. Generally, all the physico-chemical and biotic factors tending to activate metabolism, slightly increased radiostrontium intake. Concentration factors were seldom above one for animals measured in toto. According to the concentration kinetics of 85 Sr, three types of organs were distinguished: bone-type tissues, soft tissues and digestive tract [fr

  11. A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes.

    Science.gov (United States)

    Randall, D J; Rummer, J L; Wilson, J M; Wang, S; Brauner, C J

    2014-04-15

    Teleost fishes constitute 95% of extant aquatic vertebrates, and we suggest that this is related in part to their unique mode of tissue oxygenation. We propose the following sequence of events in the evolution of their oxygen delivery system. First, loss of plasma-accessible carbonic anhydrase (CA) in the gill and venous circulations slowed the Jacobs-Stewart cycle and the transfer of acid between the plasma and the red blood cells (RBCs). This ameliorated the effects of a generalised acidosis (associated with an increased capacity for burst swimming) on haemoglobin (Hb)-O2 binding. Because RBC pH was uncoupled from plasma pH, the importance of Hb as a buffer was reduced. The decrease in buffering was mediated by a reduction in the number of histidine residues on the Hb molecule and resulted in enhanced coupling of O2 and CO2 transfer through the RBCs. In the absence of plasma CA, nearly all plasma bicarbonate ultimately dehydrated to CO2 occurred via the RBCs, and chloride/bicarbonate exchange was the rate-limiting step in CO2 excretion. This pattern of CO2 excretion across the gills resulted in disequilibrium states for CO2 hydration/dehydration reactions and thus elevated arterial and venous plasma bicarbonate levels. Plasma-accessible CA embedded in arterial endothelia was retained, which eliminated the localized bicarbonate disequilibrium forming CO2 that then moved into the RBCs. Consequently, RBC pH decreased which, in conjunction with pH-sensitive Bohr/Root Hbs, elevated arterial oxygen tensions and thus enhanced tissue oxygenation. Counter-current arrangement of capillaries (retia) at the eye and later the swim bladder evolved along with the gas gland at the swim bladder. Both arrangements enhanced and magnified CO2 and acid production and, therefore, oxygen secretion to those specialised tissues. The evolution of β-adrenergically stimulated RBC Na(+)/H(+) exchange protected gill O2 uptake during stress and further augmented plasma disequilibrium states

  12. Phylogenetic perspectives on the evolution of functional hermaphroditism in teleost fishes.

    Science.gov (United States)

    Erisman, Brad E; Petersen, Christopher W; Hastings, Philip A; Warner, Robert R

    2013-10-01

    Hermaphroditism is taxonomically widespread among teleost fishes and takes on many forms including simultaneous, protogynous, and protandrous hermaphroditism, bidirectional sex change, and androdioecy. The proximate mechanisms that influence the timing, incidence, and forms of hermaphroditism in fishes are supported by numerous theoretical and empirical studies on their mating systems and sexual patterns, but few have examined aspects of sex-allocation theory or the evolution of hermaphroditism for this group within a strict phylogenetic context. Fortunately, species-level phylogenetic reconstructions of the evolutionary history of many lineages of fishes have emerged, providing opportunities for understanding fine-scale evolutionary pathways and transformations of sex allocation. Examinations of several families of fishes with adequate data on phylogeny, patterns of sex allocation, mating systems, and with some form of hermaphroditism reveal that the evolution and expression of protogyny and other forms of sex allocation show little evidence of phylogenetic inertia within specific lineages but rather are associated with particular mating systems in accordance with prevalent theories about sex allocation. Transformations from protogyny to gonochorism in groupers (Epinephelidae), seabasses (Serranidae), and wrasses and parrotfishes (Labridae) are associated with equivalent transformations in the structure of mating groups from spawning of pairs to group spawning and related increases in sperm competition. Similarly, patterns of protandry, androdioecy, simultaneous hermaphroditism, and bidirectional sex change in other lineages (Aulopiformes, Gobiidae, and Pomacentridae) match well with particular mating systems in accordance with sex-allocation theory. Unlike other animals and plants, we did not find evidence that transitions between hermaphroditism and gonochorism required functional intermediates. Two instances in which our general conclusions might not hold

  13. FMRFamide-like immunoreactive neurons of the nervus terminalis of teleosts innervate both retina and pineal organ.

    Science.gov (United States)

    Ekström, P; Honkanen, T; Ebbesson, S O

    1988-09-13

    The tetrapeptide FMRFamide (Phe-Met-Arg-Phe-NH2) was first isolated from molluscan ganglia. Subsequently, it has become clear that vertebrate brains also contain endogenous FMRFamide-like substances. In teleosts, the neurons of the nervus terminalis contain an FMRFamide-like substance, and provide a direct innervation to the retina (Proc. Natl. Acad. Sci. U.S.A., 81 [1984] 940-944). Here we report the presence of FMRFamide-immunoreactive axonal bundles in the pineal organ of Coho salmon and three-spined sticklebacks. The largest numbers of axons were observed proximal to the brain, in the pineal stalk, while the distal part of the pineal organ contained only few axons. No FMRFamide-like-immunoreactive (IR) cell bodies were observed in the pineal organ. In adult fish it was not possible to determine the origin of these axons, due to the large numbers of FMRFamide-like IR axons in the teleost brain. However, by following the development of FMRFamide-like IR neurons in the embryonic and larval stickleback brain, it was possible to conclude that, at least in newly hatched fish, FMRFamide-like IR axons that originate in the nucleus nervus terminalis reach the pineal organ. Thus, it seems there is a direct connection between a specialized part of the chemosensory system and both the retina and the pineal organ in teleost fish.

  14. Data smoothing techniques applied to proton microprobe scans of teleost hard parts

    International Nuclear Information System (INIS)

    West, I.F.; Gauldie, R.W.; Coote, G.E.

    1992-01-01

    We use a proton microprobe to examine the distribution of elements in otoliths and scales of teleost (bony) fish. The elements of principal interest are calcium and strontium in otoliths and calcium and fluorine in scales. Changes in the distribution of these elements across hard structures may allow inferences about the life histories of fish. Otoliths and scales of interest are up to a centimeter in linear dimension and to reveal the structures of interest up to 200 sampling points are required in each dimension. The time needed to accumulate high X-ray counts at each sampling point can be large, particularly for strontium. To reduce microprobe usage we use data smoothing techniques to reveal changing patterns with modest X-ray count accumulations at individual data points. In this paper we review performance for revealing pattern at modest levels of X-ray count accumulations of a selection of digital filters (moving average smoothers), running median filters, robust locally weighted regression filters and adaptive spline filters. (author)

  15. Ecomorphological selectivity among marine teleost fishes during the end-Cretaceous extinction.

    Science.gov (United States)

    Friedman, Matt

    2009-03-31

    Despite the attention focused on mass extinction events in the fossil record, patterns of extinction in the dominant group of marine vertebrates-fishes-remain largely unexplored. Here, I demonstrate ecomorphological selectivity among marine teleost fishes during the end-Cretaceous extinction, based on a genus-level dataset that accounts for lineages predicted on the basis of phylogeny but not yet sampled in the fossil record. Two ecologically relevant anatomical features are considered: body size and jaw-closing lever ratio. Extinction intensity is higher for taxa with large body sizes and jaws consistent with speed (rather than force) transmission; resampling tests indicate that victims represent a nonrandom subset of taxa present in the final stage of the Cretaceous. Logistic regressions of the raw data reveal that this nonrandom distribution stems primarily from the larger body sizes of victims relative to survivors. Jaw mechanics are also a significant factor for most dataset partitions but are always less important than body size. When data are corrected for phylogenetic nonindependence, jaw mechanics show a significant correlation with extinction risk, but body size does not. Many modern large-bodied, predatory taxa currently suffering from overexploitation, such billfishes and tunas, first occur in the Paleocene, when they appear to have filled the functional space vacated by some extinction victims.

  16. Description and comparative study of physico-chemical parameters of the teleost fish skin mucus.

    Science.gov (United States)

    Guardiola, Francisco A; Cuartero, María; Del Mar Collado-González, María; Arizcún, Marta; Díaz Baños, F Guillermo; Meseguer, José; Cuesta, Alberto; Esteban, María A

    2015-01-01

    The study of mucosal surfaces, and in particular the fish skin and its secreted mucus, has been of great interest recently among immunologists. Measurement of the viscosity and other physico-chemical parameters (protein concentration, pH, conductivity, redox potential, osmolality and density) of the skin mucus can help to understand its biological functions. We have used five marine species of teleost: gilthead seabream (Sparus aurata L.), European sea bass (Dicentrarchus labrax L.), shi drum (Umbrina cirrosa L.), common dentex (Dentex dentex L.) and dusky grouper (Epinephelus marginatus L.), all of them with commercial interest in the aquaculture of the Mediterranean area. Mucus showed a direct shear- and temperature-dependent viscosity, with a non-Newtonian behavior, which differed however between two groups: one with higher viscosity (D. labrax, U. cirrosa, D. dentex) and the other with lower viscosity (S. aurata, E. marginatus). In addition, there was a clear interrelation between density and osmolality, as well as between density and temperature. Taking into account that high values of viscosity should improve the barrier effect against pathogens but low values of viscosity are needed for good locomotion characteristics, our results may help elucidate the relationship between physico-chemical and biological parameters of skin mucus, and disease susceptibility.

  17. PACAP system evolution and its role in melanophore function in teleost fish skin.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Martins, Rute S T; Trindade, Marlene; Fonseca, Vera G; Fuentes, Juan; Power, Deborah M

    2015-08-15

    Pituitary adenylate cyclase-activating polypeptide (PACAP) administered to tilapia melanophores ex-vivo causes significant pigment aggregation and this is a newly identified function for this peptide in fish. The G-protein coupled receptors (GPCRs), adcyap1r1a (encoding Pac1a) and vipr2a (encoding Vpac2a), are the only receptors in melanophores with appreciable levels of expression and are significantly (p < 0.05) down-regulated in the absence of light. Vpac2a is activated exclusively by peptide histidine isoleucine (PHI), which suggests that Pac1a mediates the melanin aggregating effect of PACAP on melanophores. Paradoxically activation of Pac1a with PACAP caused a rise in cAMP, which in fish melanophores is associated with melanin dispersion. We hypothesise that the duplicate adcyap1ra and vipr2a genes in teleosts have acquired a specific role in skin and that the melanin aggregating effect of PACAP results from the interaction of Pac1a with Ramp that attenuates cAMP-dependent PKA activity and favours the Ca(2+)/Calmodulin dependent pathway. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Preference of the herbivorous marine teleost Siganus canaliculatus for different macroalgae

    Science.gov (United States)

    You, Cuihong; Zeng, Fangui; Wang, Shuqi; Li, Yuanyou

    2014-06-01

    The decomposition of a large amount of unexploited macroalgal resource along the coast of China often results in heavy environmental pollution. In order to pave a way of using macroalgae as the dietary ingredient of rabbitfish Siganus canaliculatus, one of a few farmed herbivorous marine teleosts in China, its preference (feeding selectivity) for different macroalgae was determined in this study. Seven seaweed species abundantly inhabiting the coast of east Guangdong Province were exposed simultaneously to rabbitfish juveniles in laboratory (multiple-choice feeding) with their content and absolute intake assayed. It was found that the most preferred algae were Ulva prolifera, Gracilaria lemaneiformis and Chaetomorpha linum, less preferred algae were U. pertusa and Porphyra haitanensis, and least preferred ones were Sargassum fusiforme and Corallina sessilis. Such an order did not change when one to four relatively preferred seaweeds were removed. The preferred seaweeds were richer in protein and soluble sugar thus higher in energy than the least preferred. In addition, this fish was found to favor filamentous and flat algae rather than calcified ones. Accordingly, the richness of nutrients and morphological characteristics determined the preference of S. canaliculatus for tested macroalgae.

  19. A fourth teleost lineage possessing extra-oral teeth: the genus atherion (teleostei; atheriniformes).

    Science.gov (United States)

    Sire, J Y; Allizard, F

    2001-12-01

    In the course of an evolutionary and developmental study on the dermal skeleton, our attention was drawn to the existence of denticles located outside the oral cavity in the atheriniform species Atherion elymus. These denticles, attached to the surface of most dermal bones of the head, are especially numerous on the snout, chin and the undersides of the lower region of the head, where they are aligned forming a crenulated keel. Using light, scanning and transmission electron microscopy, we clearly demonstrate the dental (vs bony) nature of these denticles. They are small, conical elements mostly oriented backwards and are not ankylosed to the bone support. Ligaments originating from the internal and external surface of the base of the dentine cone link the denticles to the attachment bone, which itself merges with the bone support below. The denticles have the same form and structure as teeth, from which they differ only in having a larger base and a pulp cavity that is nearly completely filled with secondary dentine by centripetal deposition. This suggests that the denticles have a longer functional history than teeth. Atherion is now the fourth teleost lineage found to develop such denticles on the head.

  20. An update on MyoD evolution in teleosts and a proposed consensus nomenclature to accommodate the tetraploidization of different vertebrate genomes.

    Directory of Open Access Journals (Sweden)

    Daniel J Macqueen

    Full Text Available BACKGROUND: MyoD is a muscle specific transcription factor that is essential for vertebrate myogenesis. In several teleost species, including representatives of the Salmonidae and Acanthopterygii, but not zebrafish, two or more MyoD paralogues are conserved that are thought to have arisen from distinct, possibly lineage-specific duplication events. Additionally, two MyoD paralogues have been characterised in the allotetraploid frog, Xenopus laevis. This has lead to a confusing nomenclature since MyoD paralogues have been named outside of an appropriate phylogenetic framework. METHODS AND PRINCIPAL FINDINGS: Here we initially show that directly depicting the evolutionary relationships of teleost MyoD orthologues and paralogues is hindered by the asymmetric evolutionary rate of Acanthopterygian MyoD2 relative to other MyoD proteins. Thus our aim was to confidently position the event from which teleost paralogues arose in different lineages by a comparative investigation of genes neighbouring myod across the vertebrates. To this end, we show that genes on the single myod-containing chromosome of mammals and birds are retained in both zebrafish and Acanthopterygian teleosts in a striking pattern of double conserved synteny. Further, phylogenetic reconstruction of these neighbouring genes using Bayesian and maximum likelihood methods supported a common origin for teleost paralogues following the split of the Actinopterygii and Sarcopterygii. CONCLUSION: Our results strongly suggest that myod was duplicated during the basal teleost whole genome duplication event, but was subsequently lost in the Ostariophysi (zebrafish and Protacanthopterygii lineages. We propose a sensible consensus nomenclature for vertebrate myod genes that accommodates polyploidization events in teleost and tetrapod lineages and is justified from a phylogenetic perspective.

  1. Unusual hepatic mitochondrial arginase in an Indian air-breathing teleost, Heteropneustes fossilis: purification and characterization.

    Science.gov (United States)

    Srivastava, Shilpee; Ratha, B K

    2013-02-01

    A functional urea cycle with both cytosolic (ARG I) and mitochondrial (ARG II) arginase activity is present in the liver of an ureogenic air-breathing teleost, Heteropneustes fossilis. Antibodies against mammalian ARG II showed no cross-reactivity with the H. fossilis ARG II. ARG II was purified to homogeneity from H. fossilis liver. Purified ARG II showed a native molecular mass of 96 kDa. SDS-PAGE showed a major band at 48 kDa. The native enzyme, therefore, appears to be a homodimer. The pI value of the enzyme was 7.5. The purified enzyme showed maximum activity at pH 10.5 and 55 °C. The K(m) of purified ARG II for l-arginine was 5.25±1.12 mM. L-Ornithine and N(ω)-hydroxy-L-arginine showed mixed inhibition with K(i) values 2.16±0.08 and 0.02±0.004 mM respectively. Mn(+2) and Co(+2) were effective activators of arginase activity. Antibody raised against purified H. fossilis ARG II did not cross-react with fish ARG I, and mammalian ARG I and ARG II. Western blot with the antibodies against purified H. fossilis hepatic ARG II showed cross reactivity with a 96 kDa band on native PAGE and a 48 kDa band on SDS-PAGE. The molecular, immunological and kinetic properties suggest uniqueness of the hepatic mitochondrial ARG II in H. fossilis. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Chronic granulomatous inflammation in teleost fish Piaractus mesopotamicus: histopathology model study

    Directory of Open Access Journals (Sweden)

    Wilson G Manrique

    2017-01-01

    Full Text Available Objective. This study evaluated the cell kinetic and formation of granuloma during chronic inflammation induced by Bacillus Calmette-Guérin (BCG in the skeletal muscle of Piaractus mesopotamicus, as a histopathology model to study innate immunity. Materials and methods. Sixty fish were divided in two groups: BCG-inoculated and non-inoculated fish and the inflammatory response analyzed 3, 7, 14, 21 and 33 days post-inoculation (DPI by histopathology after hematoxylin-eosin and Ziehl-Neelsen staining. Results. 3 DPI of BCG showed a diffuse inflammatory reaction mostly composed by mononuclear cells. The inflammation continued diffuse 7 DPI initiating the cellular organization surrounding the inoculum and have continued at 14 DPI with discrete presence of epithelioid-like type cells with acidophilic cytoplasm and floppy chromatin. Higher cellular organization (21 DPI surrounding the granuloma with intense peripheral mononuclear inflammatory infiltrate and nevertheless, an increase in the number of fibroblasts and macrophage-like cells was observed. The inflammatory process became less diffuse 33 DPI with formation of small amount of granuloma surrounded by the same type of reaction found in bigger granuloma. Both the young and old granuloma presented typical characteristic around the inoculum composed by a layer of epithelioid-like type cells, besides macrophages, some lymphocytes and abundant fibroblasts. Conclusions. This study showed the feasibility in the use of pacus to study chronic granulomatous inflammatory response induced by BCG, characterized by changes in the kinetics of inflammatory cells in skeletal muscle classifying as immune-epithelioid type, similar to granulomatous inflammation caused by M. marinum in teleost fish.

  3. Intracellular pH regulation in hepatocytes isolated from three teleost species.

    Science.gov (United States)

    Furimsky, M; Moon, T W; Perry, S F

    1999-09-01

    The mechanisms of intracellular pH (pH(i)) regulation were studied in hepatocytes isolated from three species of teleost: rainbow trout (Oncorhynchus mykiss), black bullhead (Ameiurus melas) and American eel (Anguilla rostrata). Intracellular pH was monitored over time using the pH-sensitive fluorescent dye BCECF in response to acid loading under control conditions and in different experimental media containing either low Na(+) or Cl(-) concentrations, the Na(+)-H(+) exchanger blocker amiloride or the blocker of the V-type H(+)-ATPase, bafilomycin A(1). In trout and bullhead hepatocytes, recovery to an intracellular acid load occurred principally by way of a Na(+)-dependent amiloride-sensitive Na(+)-H(+) exchanger. In eel hepatocytes, the Na(+)-H(+) exchanger did not contribute to recovery to an acid load though evidence suggests that it is present on the cell membrane and participates in the maintenance of steady-state pH(i). The V-type H(+)-ATPase did not participate in recovery to an acid load in any species. A Cl(-)-HCO(3)(-) exchanger may play a role in recovery to an acid load in eel hepatocytes by switching off and retaining base that would normally be tonically extruded. Thus, it is clear that hepatocytes isolated from the three species are capable of regulating pH(i), principally by way of a Na(+)-H(+) exchanger and a Cl(-)-HCO(3)(-) exchanger, but do not exploit identical mechanisms for pH(i) recovery. J. Exp. Zool. 284:361-367, 1999. Copyright 1999 Wiley-Liss, Inc.

  4. Neuronal nitric oxide synthase in the olfactory system of an adult teleost fish Oreochromis mossambicus.

    Science.gov (United States)

    Singru, Praful S; Sakharkar, Amul J; Subhedar, Nishikant

    2003-07-11

    The aim of the present study is to explore the distribution of nitric oxide synthase in the olfactory system of an adult teleost, Oreochromis mossambicus using neuronal nitric oxide synthase (nNOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry methods. Intense nNOS immunoreactivity was noticed in several olfactory receptor neurons (ORNs), in their axonal extensions over the olfactory nerve and in some basal cells of the olfactory epithelium. nNOS containing fascicles of the ORNs enter the bulb from its rostral pole, spread in the olfactory nerve layer in the periphery of the bulb and display massive innervation of the olfactory glomeruli. Unilateral ablation of the olfactory organ resulted in dramatic loss of nNOS immunoreactivity in the olfactory nerve layer of the ipsilateral bulb. In the olfactory bulb of intact fish, some granule cells showed intense immunoreactivity; dendrites arising from the granule cells could be traced to the glomerular layer. Of particular interest is the occurrence of nNOS immunoreactivity in the ganglion cells of the nervus terminalis. nNOS containing fibers were also encountered in the medial olfactory tracts as they extend to the telencephalon. The NADPHd staining generally coincides with that of nNOS suggesting that it may serve as a marker for nNOS in the olfactory system of this fish. However, mismatch was encountered in the case of mitral cells, while all are nNOS-negative, few were NADPHd positive. The present study for the first time revealed the occurrence of nNOS immunoreactivity in the ORNs of an adult vertebrate and suggests a role for nitric oxide in the transduction of odor stimuli, regeneration of olfactory epithelium and processing of olfactory signals.

  5. Neuropeptide Y in the olfactory system, forebrain and pituitary of the teleost, Clarias batrachus.

    Science.gov (United States)

    Gaikwad, Archana; Biju, K C; Saha, Subhash G; Subhedar, Nishikant

    2004-03-01

    Distribution of neuropeptide Y (NPY)-like immunoreactivity in the forebrain of catfish Clarias batrachus was examined with immunocytochemistry. Conspicuous immunoreactivity was seen in the olfactory receptor neurons (ORNs), their projections in the olfactory nerve, fascicles of the olfactory nerve layer in the periphery of bulb and in the medial olfactory tracts as they extend to the telencephalic lobes. Ablation of the olfactory organ resulted in loss of immunoreactivity in the olfactory nerve layer of the bulb and also in the fascicles of the medial olfactory tracts. This evidence suggests that NPY may serve as a neurotransmitter in the ORNs and convey chemosensory information to the olfactory bulb, and also to the telencephalon over the extrabulbar projections. In addition, network of beaded immunoreactive fibers was noticed throughout the olfactory bulb, which did not respond to ablation experiment. These fibers may represent centrifugal innervation of the bulb. Strong immunoreactivity was encountered in some ganglion cells of nervus terminalis. Immunoreactive fibers and terminal fields were widely distributed in the telencephalon. Several neurons of nucleus entopeduncularis were moderately immunoreactive; and a small population of neurons in nucleus preopticus periventricularis was also labeled. Immunoreactive terminal fields were particularly conspicuous in the preoptic, the tuberal areas, and the periventricular zone around the third ventricle and inferior lobes. NPY immunoreactive cells and fibers were detected in all the lobes of the pituitary gland. Present results describing the localization of NPY in the forebrain of C. batrachus are in concurrence with the pattern of the immunoreactivity encountered in other teleosts. However, NPY in olfactory system of C. batrachus is a novel feature that suggests a role for the peptide in processing of chemosensory information.

  6. Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Bassity, Elizabeth; Clark, Theodore G.

    2012-01-01

    Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

  7. Independently evolved upper jaw protrusion mechanisms show convergent hydrodynamic function in teleost fishes.

    Science.gov (United States)

    Staab, Katie Lynn; Holzman, Roi; Hernandez, L Patricia; Wainwright, Peter C

    2012-05-01

    A protrusible upper jaw has independently evolved multiple times within teleosts and has been implicated in the success of two groups in particular: Acanthomorpha and Cypriniformes. We use digital particle image velocimetry (DPIV) to compare suction feeding flow dynamics in a representative of each of these clades: goldfish and bluegill. Using DPIV, we contrast the spatial pattern of flow, the temporal relationship between flow and head kinematics, and the contribution of jaw protrusion to the forces exerted on prey. As expected, the spatial patterns of flow were similar in the two species. However, goldfish were slower to reach maximal kinematic excursions, and were more flexible in the relative timing of jaw protrusion, other jaw movements and suction flows. Goldfish were also able to sustain flow speeds for a prolonged period of time as compared with bluegill, in part because goldfish generate lower peak flow speeds. In both species, jaw protrusion increased the force exerted on the prey. However, slower jaw protrusion in goldfish resulted in less augmentation of suction forces. This difference in force exerted on prey corresponds with differences in trophic niches and feeding behavior of the two species. The bluegill uses powerful suction to capture insect larvae whereas the goldfish uses winnowing to sort through detritus and sediment. The kinethmoid of goldfish may permit jaw protrusion that is independent of lower jaw movement, which could explain the ability of goldfish to decouple suction flows (due to buccal expansion) from upper jaw protrusion. Nevertheless, our results show that jaw protrusion allows both species to augment the force exerted on prey, suggesting that this is a fundamental benefit of jaw protrusion to suction feeders.

  8. CRTAC1 homolog proteins are conserved from cyanobacteria to man and secreted by the teleost fish pituitary gland.

    Science.gov (United States)

    Redruello, Begoña; Louro, Bruno; Anjos, Liliana; Silva, Nádia; Greenwell, Roger S; Canario, Adelino V M; Power, Deborah M

    2010-05-15

    Cartilage acidic protein 1 (CRTAC1) gene expression is used as a marker for chondrocyte differentiation in stem cell-based tissue engineering. It is also transcribed outside the skeleton where at least two different transcripts are expressed in lung and brain. In the pituitary gland of the teleost fish sea bream Sparus auratus, we have found a transcript with a high degree of sequence identity to CRTAC1 family members but lacking the EGF-like calcium-binding domain encoding sequence of CRTAC1 and designated it as CRTAC2. Database searches revealed many previously unidentified members of the CRTAC1 and CRTAC2 in phylogenetically distant organisms, such as cyanobacteria, bryophyta, lancelets, and diverse representatives of vertebrates. Phylogenetic analyses showed that the genes encoding CRTAC1 and CRTAC2 proteins coexist in teleost fish genomes. Structural prediction analysis identified the N-terminal region of the CRTAC1/CRTAC2 family members as a potential seven-bladed beta-propeller structure, closely related to those of integrin alpha chains and glycosylphosphatidylinositol-specific phospholipase D1 protein families. This relationship is confirmed by phylogenetic analysis with the N-terminal domain of sea bream CRTAC2 as the most divergent sequence. Because teleost fishes are the only phylogenetic group where both CRTAC1 and CRTAC2 genes are present, they occupy a pivotal position in studies of the mechanisms governing the specific expression patterns of each gene/protein subfamily. This will be essential to elucidate their respective biological roles. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Encephalization in tropical teleost fishes and comparison with their mode of life.

    Science.gov (United States)

    Bauchot, R; Randall, J E; Ridet, J M; Bauchot, M L

    1989-01-01

    The brains were dissected from a total of 1225 fishes representing 737 species, 310 genera and 113 families of tropical and subtropical teleosts. Each fish was weighed before brain dissection, and each brain weighed after its removal. The encephalization coefficient k was determined for each fish from a quadratic formula; to conveniently compare brain size of one species with that of another, we used an encephalization index so that an encephalization index of 100 is the average for all the species investigated. The encephalization indices for the families of fishes studied varied from 7 for the Moringuidae to 233 for the Coryphaenidae. There is no strong correlation in relative brain size with phylogenetic position. Although there is a general trend for the more highly evolved fishes to have larger brains, this is partially obscured by some high values in certain primitive groups and low ones in the more advanced. Elongate fishes have lower encephalization indices in general. This may in part be related to low phylogenetic position of most elongate species (anguilliform fishes, for example), in part to the greater relative body weight due to the longer vertebral column (and usually more numerous fin rays as as well), and to their usual mode of swimming by lateral undulations of the body (the most primitive type of aquatic locomotion--one in which the spinal cord plays a major role). No difference could be noted in the encephalization indices of herbivorous families of fishes compared to carnivorous ones. Within a genus, among medium to large-size fishes, those species of larger size tend to have lower encephalization indices. This may be related to larger fishes having less to fear of predators. Fishes which in some passive way avoid predation have low indices in general. This is particularly true of benthic species which conceal themselves by flattened form, fleshy protuberances or protective coloration, or which bury in the sediment or take refuge in burrows

  10. Assessment of gold nanoparticle effects in a marine teleost (Sparus aurata) using molecular and biochemical biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Teles, M., E-mail: mteles0@gmail.com [Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Fierro-Castro, C. [Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Na-Phatthalung, P. [Department of Microbiology and Excellent Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Tvarijonaviciute, A. [Department of Medicine and Animal Surgery, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Trindade, T. [Department of Chemistry & CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Soares, A.M.V.M. [Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro (Portugal); Tort, L. [Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Oliveira, M. [Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

    2016-08-15

    Highlights: • AuNP effects were investigated at molecular and biochemical levels in Sparus aurata. • AuNP coated with PVP exerts more effects than AuNP coated with citrate. • AuNP-PVP induced changes in antioxidant, immune and apoptosis related-genes mRNA levels. • The increase in plasma TOS indicates that AuNP-PVP generates oxidative stress. • AuNP-PVP induced in S. aurata a non-monotonic response pattern. - Abstract: Gold nanoparticles (AuNP) are increasingly employed in a variety of applications and are likely to be increasing in the environment, posing a potential emerging environmental threat. Information on possible hazardous effects of engineered nanoparticles is urgently required to ensure human and environmental safety and promote the safe use of novel nanotechnologies. Nevertheless, there is a lack of comprehensive knowledge on AuNP effects in marine species. The present study aimed to assess AuNP effects in a marine teleost, Sparus aurata, by combining endpoints at different biological levels (molecular and biochemical). For that purpose, fish were exposed via water for 96 h to 4, 80 and 1600 μg L{sup −1} of AuNP (∼40 nm) coated with citrate or polyvinylpyrrolidone (PVP). Results revealed a significant impact of AuNP-PVP in the hepatic expression of antioxidant, immune and apoptosis related genes. Total oxidative status was increased in plasma after exposure to the lowest concentration of AuNP-PVP, although without altering the total antioxidant capacity. Furthermore, AuNP did not induce significant damage in the liver since the activity of neither hepatic indicator (aspartate aminotransferase and alkaline phosphatase) increased. Overall, the present study demonstrated that AuNP, even with a biocompatible coating is able to alter oxidative status and expression of relevant target genes in marine fish. Another important finding is that effects are mainly induced by the lowest and intermediate concentrations of the PVP coated AuNP revealing

  11. Assessment of gold nanoparticle effects in a marine teleost (Sparus aurata) using molecular and biochemical biomarkers

    International Nuclear Information System (INIS)

    Teles, M.; Fierro-Castro, C.; Na-Phatthalung, P.; Tvarijonaviciute, A.; Trindade, T.; Soares, A.M.V.M.; Tort, L.; Oliveira, M.

    2016-01-01

    Highlights: • AuNP effects were investigated at molecular and biochemical levels in Sparus aurata. • AuNP coated with PVP exerts more effects than AuNP coated with citrate. • AuNP-PVP induced changes in antioxidant, immune and apoptosis related-genes mRNA levels. • The increase in plasma TOS indicates that AuNP-PVP generates oxidative stress. • AuNP-PVP induced in S. aurata a non-monotonic response pattern. - Abstract: Gold nanoparticles (AuNP) are increasingly employed in a variety of applications and are likely to be increasing in the environment, posing a potential emerging environmental threat. Information on possible hazardous effects of engineered nanoparticles is urgently required to ensure human and environmental safety and promote the safe use of novel nanotechnologies. Nevertheless, there is a lack of comprehensive knowledge on AuNP effects in marine species. The present study aimed to assess AuNP effects in a marine teleost, Sparus aurata, by combining endpoints at different biological levels (molecular and biochemical). For that purpose, fish were exposed via water for 96 h to 4, 80 and 1600 μg L"−"1 of AuNP (∼40 nm) coated with citrate or polyvinylpyrrolidone (PVP). Results revealed a significant impact of AuNP-PVP in the hepatic expression of antioxidant, immune and apoptosis related genes. Total oxidative status was increased in plasma after exposure to the lowest concentration of AuNP-PVP, although without altering the total antioxidant capacity. Furthermore, AuNP did not induce significant damage in the liver since the activity of neither hepatic indicator (aspartate aminotransferase and alkaline phosphatase) increased. Overall, the present study demonstrated that AuNP, even with a biocompatible coating is able to alter oxidative status and expression of relevant target genes in marine fish. Another important finding is that effects are mainly induced by the lowest and intermediate concentrations of the PVP coated AuNP revealing the

  12. Structural and functional effects of acoustic exposure in goldfish: evidence for tonotopy in the teleost saccule

    Directory of Open Access Journals (Sweden)

    Gilley Ronald R

    2011-02-01

    Full Text Available Abstract Background Mammalian and avian auditory hair cells display tonotopic mapping of frequency along the length of the cochlea and basilar papilla. It is not known whether the auditory hair cells of fishes possess a similar tonotopic organization in the saccule, which is thought to be the primary auditory receptor in teleosts. To investigate this question, we determined the location of hair cell damage in the saccules of goldfish (Carassius auratus following exposure to specific frequencies. Subjects were divided into six groups of six fish each (five treatment groups plus control. The treatment groups were each exposed to one of five tones: 100, 400, 800, 2000, and 4000 Hz at 176 dB re 1 μPa root mean squared (RMS for 48 hours. The saccules of each fish were dissected and labeled with phalloidin in order to visualize hair cell bundles. The hair cell bundles were counted at 19 specific locations in each saccule to determine the extent and location of hair cell damage. In addition to quantification of anatomical injury, hearing tests (using auditory evoked potentials were performed on each fish immediately following sound exposure. Threshold shifts were calculated by subtracting control thresholds from post-sound exposure thresholds. Results All sound-exposed fish exhibited significant hair cell and hearing loss following sound exposure. The location of hair cell loss varied along the length of the saccule in a graded manner with the frequency of sound exposure, with lower and higher frequencies damaging the more caudal and rostral regions of the saccule, respectively. Similarly, fish exposed to lower frequency tones exhibited greater threshold shifts at lower frequencies, while high-frequency tone exposure led to hearing loss at higher frequencies. In general, both hair cell and hearing loss declined as a function of increasing frequency of exposure tone, and there was a significant linear relationship between hair cell loss and hearing

  13. The isolation, purification and amino-acid sequence of insulin from the teleost fish Cottus scorpius (daddy sculpin).

    Science.gov (United States)

    Cutfield, J F; Cutfield, S M; Carne, A; Emdin, S O; Falkmer, S

    1986-07-01

    Insulin from the principal islets of the teleost fish, Cottus scorpius (daddy sculpin), has been isolated and sequenced. Purification involved acid/alcohol extraction, gel filtration, and reverse-phase high-performance liquid chromatography to yield nearly 1 mg pure insulin/g wet weight islet tissue. Biological potency was estimated as 40% compared to porcine insulin. The sculpin insulin crystallised in the absence of zinc ions although zinc is known to be present in the islets in significant amounts. Two other hormones, glucagon and pancreatic polypeptide, were copurified with the insulin, and an N-terminal sequence for pancreatic polypeptide was determined. The primary structure of sculpin insulin shows a number of sequence changes unique so far amongst teleost fish. These changes occur at A14 (Arg), A15 (Val), and B2 (Asp). The B chain contains 29 amino acids and there is no N-terminal extension as seen with several other fish. Presumably as a result of the amino acid substitutions, sculpin insulin does not readily form crystals containing zinc-insulin hexamers, despite the presence of the coordinating B10 His.

  14. Rodlet cells changes in Oreochromis niloticus in response to organophosphate pesticide and their relevance as stress biomarker in teleost fishes

    Directory of Open Access Journals (Sweden)

    Natalia de Souza Araujo

    2016-01-01

    Full Text Available Rodlet cells are frequently found in teleost fishes and although their role in organisms is not completely understood. The occurrence of these cells are related to stress and may undergo changes in contaminated environments, thereby allowing their use as biomarkers. This hypothesis is tested in the present study. Thirty specimens of Oreochromis niloticus were divided into three groups, two groups were exposed to organophosphate pesticide methyl parathion at nominal concentrations of 4 mgl-1 and 8 mgl-1 and one group was kept as control. After ten days, the gills were removed for microscopic study and the number and area of the rodlet cells were analyzed and compared with a well-established method of assessing histological damages in fishes. No significant differences were found in the area of the cells, but there were significant differences in the number of rodlet cells among examined concentrations. The present study provides evidence for the use of this new biomarker in teleost fishes and discusses some of the potential confounding factors of this approach.

  15. Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth.

    Science.gov (United States)

    Jackman, William R; Davies, Shelby H; Lyons, David B; Stauder, Caitlin K; Denton-Schneider, Benjamin R; Jowdry, Andrea; Aigler, Sharon R; Vogel, Scott A; Stock, David W

    2013-01-01

    Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth. © 2013 Wiley Periodicals, Inc.

  16. Expression and distribution of the glucocorticoid receptor DlGR1 in the teleost Dicentrarchus labrax brain

    Directory of Open Access Journals (Sweden)

    Nicolò Parrinello

    2010-01-01

    Full Text Available Cortisol is the main corticosteroid secreted by the interrenal cells of the head kidney and it exerts a role in mantaining the omeostatic status in fish. In teleosts its effects are mediated through intracellular receptors expressed in several tissues, that are ligand-dependent transcription factors by binding to specific tissue DNA sequences. In Dicentrarchus labrax we previously cloned and sequenced a glucocorticoid receptor, DlGR1, isolated from leukocytes of peritoneal cavity. In this work we showed mRNA expression and tissue immunohistochemical localization of brain DlGR1 by in situ hybridization assays, with a riboprobe with DlGR1 cDNA trascriptional activation domain, and by immunohistochemical methods, using a specific antibody for a selected sequence of the receptor tran- scriptional domain. The mRNA and the protein are expressed in pyramidal cells of the optic lobe and in the small globular neurons of the diencephalon.

  17. Identification of FXYD Protein Genes in a Teleost: Tissue-specific Expression and Response to Salinity Change

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk

    2008-01-01

    identified. Phylogenetic analysis suggests that six isoforms are homologues to the previously identified FXYD2, FXYD5, FXYD6, FXYD7, FXYD8 and FXYD9, while two additional isoforms were found (FXYD11 and FXYD12). Using quantitative PCR, tissue dependent expression of the different isoforms was analyzed......). In osmoregulatory tissues, one isoform was expressed predominantly in gill (FXYD11), one in kidney (FXYD2) and one equally in kidney and intestine (FXYD12). Expression of several FXYD genes in kidney and gill differed between fresh water and seawater salmon suggesting significance during osmoregulatory adaptations....... In addition to identify novel FXYD isoforms, these studies are the first to show the tissue dependence in their expression and modulation by salinity in any teleosts. Key words: Atlantic salmon, Na+,K+-ATPase, Osmoregulation, Salmo salar, QPCR....

  18. Effects of different dietary DHA:EPA ratios on gonadal steroidogenesis in the marine teleost, tongue sole (Cynoglossus semilaevis).

    Science.gov (United States)

    Xu, Houguo; Cao, Lin; Wei, Yuliang; Zhang, Yuanqin; Liang, Mengqing

    2017-08-01

    The present study was conducted to investigate the effects of dietary DHA and EPA on gonadal steroidogenesis in mature females and males, with a feeding trial on tongue sole, a typical marine teleost with sexual dimorphism. Three experimental diets differing basically in DHA:EPA ratio, that is, 0·68 (diet D:E-0·68), 1·09 (D:E-1·09) and 2·05 (D:E-2·05), were randomly assigned to nine tanks of 3-year-old tongue sole (ten females and fifteen males in each tank). The feeding trail lasted for 90 d before and during the spawning season. Fish were reared in a flowing seawater system and fed to apparent satiation twice daily. Compared with diet D:E-0·68, diet D:E-1·09 significantly enhanced the oestradiol production in females, whereas diet D:E-2·05 significantly enhanced the testosterone production in males. In ovaries, diet D:E-1·09 induced highest mRNA expression of follicle-stimulating hormone receptor (FSHR), steroidogenic acute regulatory protein, 17α-hydroxylase (P450c17) and 3β-hydroxysteroid dehydrogenase (3β-HSD). In testes, diet 2·05 resulted in highest mRNA expression of FSHR, cholesterol side-chain cleavage enzyme, P450c17 and 3β-HSD. Fatty acid profiles in fish tissues reflected closely those of diets. Female fish had more gonadal EPA content but less DHA content than male fish, whereas there was a reverse observation in liver. In conclusion, the dietary DHA:EPA ratio, possibly combined with the dietary EPA:arachidonic acid ratio, differentially regulated sex steroid hormone synthesis in mature female and male tongue soles. Females seemed to require more EPA but less DHA for the gonadal steroidogenesis than males. The results are beneficial to sex-specific nutritive strategies in domestic teleost.

  19. Profiling of gene duplication patterns of sequenced teleost genomes: evidence for rapid lineage-specific genome expansion mediated by recent tandem duplications.

    Science.gov (United States)

    Lu, Jianguo; Peatman, Eric; Tang, Haibao; Lewis, Joshua; Liu, Zhanjiang

    2012-06-15

    Gene duplication has had a major impact on genome evolution. Localized (or tandem) duplication resulting from unequal crossing over and whole genome duplication are believed to be the two dominant mechanisms contributing to vertebrate genome evolution. While much scrutiny has been directed toward discerning patterns indicative of whole-genome duplication events in teleost species, less attention has been paid to the continuous nature of gene duplications and their impact on the size, gene content, functional diversity, and overall architecture of teleost genomes. Here, using a Markov clustering algorithm directed approach we catalogue and analyze patterns of gene duplication in the four model teleost species with chromosomal coordinates: zebrafish, medaka, stickleback, and Tetraodon. Our analyses based on set size, duplication type, synonymous substitution rate (Ks), and gene ontology emphasize shared and lineage-specific patterns of genome evolution via gene duplication. Most strikingly, our analyses highlight the extraordinary duplication and retention rate of recent duplicates in zebrafish and their likely role in the structural and functional expansion of the zebrafish genome. We find that the zebrafish genome is remarkable in its large number of duplicated genes, small duplicate set size, biased Ks distribution toward minimal mutational divergence, and proportion of tandem and intra-chromosomal duplicates when compared with the other teleost model genomes. The observed gene duplication patterns have played significant roles in shaping the architecture of teleost genomes and appear to have contributed to the recent functional diversification and divergence of important physiological processes in zebrafish. We have analyzed gene duplication patterns and duplication types among the available teleost genomes and found that a large number of genes were tandemly and intrachromosomally duplicated, suggesting their origin of independent and continuous duplication

  20. Temperature, salinity, and nutrients data from CTD and bottle casts in the Arctic, North Atlantic, North Pacific Oceans from the TELEOST and other platforms from 01 August 1960 to 22 April 2000 (NODC Accession 0000496)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, bottle, and other data were collected in the Arctic, North Atlantic, and Pacific Oceans from the TELEOST and other platforms from 01 August 1960 to 22 April...

  1. Homoeologous Recombination of the V1r1-V1r2 Gene Cluster of Pheromone Receptors in an Allotetraploid Lineage of Teleosts

    Directory of Open Access Journals (Sweden)

    Lei Zhong

    2017-11-01

    Full Text Available In contrast to other olfactory receptor families that exhibit frequent lineage-specific expansions, the vomeronasal type 1 receptor (V1R family exhibits a canonical six-member repertoire in teleosts. V1r1 and V1r2 are present in no more than one copy in all examined teleosts, including salmons, which are ancient polyploids, implying strict evolutionary constraints. However, recent polyploids have not been examined. Here, we identified a young allotetraploid lineage of weatherfishes and investigated their V1r1-V1r2 cluster. We found a novel pattern that the parental V1r1-V1r2 clusters had recombined in the tetraploid genome and that the recombinant was nearly fixed in the tetraploid population. Subsequent analyses suggested strong selective pressure, for both a new combination of paralogs and homogeneity among gene duplicates, acting on the V1r1-V1r2 pair.

  2. Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians.

    Science.gov (United States)

    Martyniuk, Christopher J; Bissegger, Sonja; Langlois, Valérie S

    2013-12-01

    The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2

  3. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    International Nuclear Information System (INIS)

    Mishra, Ashish K.; Mohanty, Banalata

    2009-01-01

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  4. WNK1 and p38-MAPK distribution in ionocytes and accessory cells of euryhaline teleost fish implies ionoregulatory function

    Directory of Open Access Journals (Sweden)

    W. S. Marshall

    2017-07-01

    Full Text Available Ionocytes of euryhaline teleost fish secrete NaCl, under regulation by serine and threonine kinases, including with-no-lysine kinase (WNK1 and p38 mitogen-activated protein kinase (MAPK. Mummichogs (Fundulus heteroclitus L. were acclimated to freshwater (FW, full strength seawater (SW and hypersaline conditions (2SW. Immunocytochemistry of ionocytes in opercular epithelia of fish acclimated to SW and 2SW revealed that WNK1-anti-pT58 phosphoantibody localized strongly to accessory cells and was present in the cytosol of ionocytes, close to cystic fibrosis transmembrane conductance regulator (CFTR in the apical membrane and the sodium potassium 2 chloride cotransporter (NKCC in the basolateral membrane. In FW acclimated fish, WNK1 localized to a sub-apical zone, did not colocalize with apical membrane-located sodium chloride cotransporter (NCC, and typically was present in one cell of paired ionocytes and in some single ionocytes. Forskolin treatment (10 μM, 30 min increased WNK1 immunofluorescence in SW ionocytes only, while hypertonicity had little effect, compared to controls. Anti-p38-MAPK antibody localized to the cytosolic compartment. The distribution of WNK1 and p38MAPK is consistent with a proximal position in regulatory cascades, rather than directly affecting transporters. The strong staining of accessory cells by WNK1 phosphoantibody infers an osmoregulatory function for WNK.

  5. Complementary description of Ergasilus arthrosis Roberts, 1969 (Copepoda: Poecilostomatoida: Ergasilidae), a new parasite of cichlid teleosts in southeast Mexico.

    Science.gov (United States)

    Jiménez-García, María Isabel; Suárez-Morales, Eduardo

    2017-01-01

    During a parasitological survey of the ichthyofauna of Lake Catemaco, a freshwater system in the Mexican State of Veracruz, the widespread copepod Ergasilus arthrosis Roberts, 1969 was recovered from two cichlid teleosts, Mayaheros urophthalmus (Günther) and Oreochromis sp. This is the first confirmed record of this copepod species outside of the United States and from Mexico; its finding as a parasite of cichlids represents an expansion of the known host range for this copepod. The local prevalence and intensity of infection of E. arthrosis was highest in M. urophthalmus. The infection prevalence of E. arthrosis on M. urophthalmus (60%) was higher than that known for other ergasilids on cichlids. Ergasilus arthrosis can be distinguished from its closest congener E. lizae Krøyer, 1863 by the morphometry of the antennary segments, the ventral ornamentation of the thoracic sclerites and by details of the antennulary setation, but also by its habitat and host preferences. Taxonomic illustrations and morphological details of the specimens examined are also provided together with comments on the variability of this species.

  6. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Ashish K. [Department of Zoology, University of Allahabad, Allahabad-211002 (India); Mohanty, Banalata, E-mail: drbana_mohanty@rediffmail.com [Department of Zoology, University of Allahabad, Allahabad-211002 (India)

    2009-09-01

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  7. Duplication of Dio3 genes in teleost fish and their divergent expression in skin during flatfish metamorphosis.

    Science.gov (United States)

    Alves, R N; Cardoso, J C R; Harboe, T; Martins, R S T; Manchado, M; Norberg, B; Power, D M

    2017-05-15

    Deiodinase 3 (Dio3) plays an essential role during early development in vertebrates by controlling tissue thyroid hormone (TH) availability. The Atlantic halibut (Hippoglossus hippoglossus) possesses duplicate dio3 genes (dio3a and dio3b). Expression analysis indicates that dio3b levels change in abocular skin during metamorphosis and this suggests that this enzyme is associated with the divergent development of larval skin to the juvenile phenotype. In larvae exposed to MMI, a chemical that inhibits TH production, expression of dio3b in ocular skin is significantly up-regulated suggesting that THs normally modulate this genes expression during this developmental event. The molecular basis for divergent dio3a and dio3b expression and responsiveness to MMI treatment is explained by the multiple conserved TREs in the proximal promoter region of teleost dio3b and their absence from the promoter of dio3a. We propose that the divergent expression of dio3 in ocular and abocular skin during halibut metamorphosis contributes to the asymmetric pigment development in response to THs. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Sexual phenotype differences in zic2 mRNA abundance in the preoptic area of a protogynous teleost, Thalassoma bifasciatum.

    Directory of Open Access Journals (Sweden)

    Katherine McCaffrey

    Full Text Available The highly conserved members of the zic family of zinc-finger transcription factors are primarily known for their roles in embryonic signaling pathways and regulation of cellular proliferation and differentiation. This study describes sexual phenotype differences in abundances of zic2 mRNA in the preoptic area of the hypothalamus, a region strongly implicated in sexual behavior and function, in an adult teleost, Thalassoma bifasciatum. The bluehead wrasse (Thalassoma bifasciatum is a valuable model for studying neuroendocrine processes because it displays two discrete male phenotypes, initial phase (IP males and territorial, terminal phase (TP males, and undergoes socially-controlled protogynous sex change. Previously generated microarray-based comparisons suggested that zic2 was upregulated in the brains of terminal phase males relative to initial phase males. To further explore this difference, we cloned a 727 bp sequence for neural zic2 from field-collected animals. Riboprobe-based in situ hybridization was employed to localize zic2 signal in adult bluehead brains and assess the relative abundance of brain zic2 mRNA across sexual phenotypes. We found zic2 mRNA expression was extremely abundant in the granular cells of the cerebellum and widespread in other brain regions including in the thalamus, hypothalamus, habenula, torus semicircularis, torus longitudinalis, medial longitudinal fascicle and telencephalic areas. Quantitative autoradiography and phosphorimaging showed zic2 mRNA hybridization signal in the preoptic area of the hypothalamus was significantly higher in terminal phase males relative to both initial phase males and females, and silver grain analysis confirmed this relationship between phenotypes. No significant difference in abundance was found in zic2 signal across phenotypes in the habenula, a brain region not implicated in the control of sexual behavior, or cerebellum.

  9. Diversity, molecular characterization and expression of T cell receptor γ in a teleost fish, the sea bass (Dicentrarchus labrax, L.

    Directory of Open Access Journals (Sweden)

    Francesco Buonocore

    Full Text Available Two lineages of T cells, expressing either the αβ T cell receptor (TR or the γδ TR, exist in Gnathostomes. The latter type of T cells account for 1-10 % of T cells in blood and up to 30 % in the small intestine. They may recognize unconventional antigens (phosphorylated microbial metabolites, lipid antigens without the need of major histocompatibility class I (MH1 or class II (MH2 presentation. In this work we have described cloning and structural characterization of TR -chain (TRG from the teleost Dicentrarchus labrax. Further, by means of quantitative PCR analysis, we analyzed TRG expression levels both in poly I:C stimulated leukocytes in vitro, and following infection with betanodavirus in vivo. Two full length cDNAs relative to TRG, with the highest peptide and nucleotide identity with Japanese flounder, were identified. A multiple alignment analysis showed the conservation of peptides fundamental for TRG biological functions, and of the FGXG motif in the FR4 region, typical of most TR and immunoglobulin light chains. A 3D structure consisting of two domains mainly folded as beta strands with a sandwich architecture for each domain was also reported. TRG CDR3 of 8-18 AA in length and diversity in the TRG rearrangements expressed in thymus and intestine for a given V/C combination were evidenced by junction length spectratyping. TRG mRNA expression levels were high in basal conditions both in thymus and intestine, while in kidney and gut leukocytes they were up-regulated after in vitro stimulation by poly I:C. Finally, in juveniles the TRG expression levels were up-regulated in the head kidney and down-regulated in intestine after in vivo infection with betanodavirus. Overall, in this study the involvement of TRG-bearing T cells during viral stimulation was described for the first time, leading to new insights for the identification of T cell subsets in fish.

  10. The glucocorticoid stress response is attenuated but unrelated to reproductive investment during parental care in a teleost fish.

    Science.gov (United States)

    O'Connor, Constance M; Yick, Claire Y; Gilmour, Kathleen M; Van Der Kraak, Glen; Cooke, Steven J

    2011-01-15

    We investigated whether circulating glucocorticoids and androgens are correlated with reproductive investment in smallmouth bass (Micropterus dolomieu), a teleost fish with sole paternal care. Circulating cortisol and androgens prior to and 25 min following a standardized 3 min emersion stressor were quantified for non-reproductive and parental fish across the parental care period. To experimentally investigate the influence of reproductive investment on endocrine parameters, we manipulated brood size (reduced, enlarged, sham-treated, or unmanipulated) 24h prior to sampling parental fish. We predicted that fish guarding offspring would exhibit increased androgens and baseline cortisol levels, and an attenuated cortisol response to the stressor when compared with non-reproductive individuals. We further predicted that these effects would scale with reproductive investment. As predicted, parental care-providing fish exhibited lower post-stress plasma cortisol concentrations than non-reproductive fish. This difference was strongest early during parental care. However, no differences in baseline or post-stress cortisol concentrations were detected among parents guarding offspring with varying brood sizes. There was, however, a trend for parental fish to exhibit an increased cortisol response following brood manipulation, regardless of the direction of change in brood size, a response that likely reflected disturbance. No differences were found in baseline cortisol concentrations. Circulating androgens were found to be highest during early parental care, and no differences were found among parents guarding manipulated broods. Collectively, these findings demonstrate that the endocrine stress response is affected by reproductive status, but the response in this model species does not appear to be scaled according to reproductive investment as predicted by life-history theory. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Cold-shock eliminates female nucleus in fertilized eggs to induce androgenesis in the loach (Misgurnus anguillicaudatus, a teleost fish

    Directory of Open Access Journals (Sweden)

    Morishima Kagayaki

    2011-11-01

    Full Text Available Abstract Background Androgenesis (all-male inheritance is generally induced by means of irradiating the eggs to inactivate the maternal genome, followed by fertilization with normal sperm. In fish, the conventional technique for induced androgenesis has been applied for rapid fixation to traits, recovery of cryopreserved genotypes, sex-control, etc. A new method of androgenesis that eliminates the need to irradiate the egg was proposed using the loach, Misgurnus anguillicaudatus (a teleost fish. Results When the eggs of wild-type females were fertilized with sperm of albino or orange phenotype males and cold-shocked at 0 to 3°C for 60 min duration just after fertilization, generally more than 30% (with a peak of 100% of the hatched progeny were androgenotes. While a few of them were the normal diploid, most of them turned out to be abnormal haploid. All-male inheritance was verified by the expression of the recessive color trait (albino or orange and microsatellite genotypes comprising only paternally derived alleles. Nuclear behavior after the cold-shock treatment was traced by microscopic observation of DAPI (4'6-diamidino-2-phenylindole-stained samples and hematoxylin-eosin stained histological sections, and the extrusion of egg (maternal nucleus was observed in eggs treated in the optimum timing. Conclusion In this paper, we demonstrate that cold-shock treatment (at 0 and 3°C of loach eggs for 60 min just after fertilization successfully induces androgenetic haploid development. The most likely mechanism of cold-shock induced androgenesis is an elimination of the egg nucleus together along with the second polar body and subsequent development of a decondensed sperm nucleus or male pronucleus.

  12. Recognition of Lipopolysaccharide and Activation of NF-κB by Cytosolic Sensor NOD1 in Teleost Fish

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    Dekun Bi

    2018-06-01

    Full Text Available Lipopolysaccharide (LPS is the major component of the outer membrane of Gram-negative bacteria. This molecule can induce strong immune response and various biological effects. In mammals, TLR4 can recognize LPS and induce inflammatory response. However, the innate receptor in fish for recognizing LPS remains ambiguous. LPS can invade the cytoplasm via outer membrane vesicles produced by Gram-negative bacteria and could be detected by intracellular receptor caspase-11 in mammals, so, there may also exist the intracellular receptors that can recognize LPS in fish. NOD1 is a member of NOD-like receptors family and can recognize the iE-DAP in the cytoplasm in mammals. In fish, NOD1 can also respond to infection of Gram-negative bacteria and may play an important role in the identification of bacterial components. In this study, to study whether NOD1 is a recognition receptor for LPS, we detected the expression of NOD1 and several cytokines at transcript levels to determine whether LPS can induce inflammatory response in teleost fish and NOD1 can respond to LPS. Then, we perform the binding analysis between NOD1 and ultrapure LPS by using Streptavidin pulldown assay and enzyme-linked immunosorbent assay to prove that NOD1 can be combined with LPS, and using dual luciferase reporter gene assay to verify the signal pathways activated by NOD1. Next, through cell viability analysis, we proved that LPS-induced cytotoxicity can be mediated by NOD1 in fish. The results showed that NOD1 can identify LPS and activate the NF-κB signal pathway by recruiting RIPK2 and then promoting the expression of inflammatory cytokines to induce the resistance of organism against bacterial infection.

  13. Pattern of expression of immune-relevant genes in the gonad of a teleost, the gilthead seabream (Sparus aurata L.).

    Science.gov (United States)

    Chaves-Pozo, E; Liarte, S; Fernández-Alacid, L; Abellán, E; Meseguer, J; Mulero, V; García-Ayala, A

    2008-05-01

    Immune responses in the testis are regulated in a way that provides protection for the developing male germ cells, while permitting qualitatively normal inflammatory responses and protection against infection. In addition, germ cells are potent targets for the growth factors and cytokines which regulate the reproductive process. Our study analyzes for the first time the pattern of expression of several immune-relevant genes in the gonad of a seasonal breeding teleost fish. The immune molecules analyzed include (i) inflammatory molecules, such as interleukin-1b (il1b), il6, tumor necrosis factor-a (tnfa), cyclooxygenase-2 (cox2) and the NADPH oxidase subunit p40(phox) (ncf4 gene); (ii) the anti-inflammatory cytokine transforming growth factor-b1 (tgfb1) and its type 2 receptor tgfbr2; (iii) innate immune receptors, including toll-like receptor 9 (tlr9), tlr5, tlr22 and macrophage-colony stimulating factor receptor (mcsfr); (iv) lymphocyte receptors, such as the beta subunit of T-cell receptor (Tcrb) and the heavy chain of immunoglobulin M (ighm); (v) the anti-bacterial molecules lysozyme (lyz), hepcidin (hamp) and complement component 3 (c3); (vi) the anti-viral molecule myxovirus (influenza) resistance protein (mx); and (vii) molecules related to leukocyte infiltration, including the CC chemokine ccl4, the CXC chemokine il8 and the leukocyte adhesion molecule E-selectin (Sele). Notably, all of them show a pattern of expression that depends on the reproductive stage of the first two reproductive cycles when the fish develop and function as males. Furthermore, we demonstrate that some of these immune-relevant molecules, such as Il1b and Mcsfr, are produced by germ cells (Il1b) and ovarian and testicular somatic cells (Mcsfr). These data suggest that, as occurs in mammals, there is a critical balance between immune molecules and that these may play an essential role in the orchestration of gametogenesis and the maintenance of gonad tissue homeostasis in fish.

  14. Gene expression of thyrotropin- and corticotrophin-releasing hormones is regulated by environmental salinity in the euryhaline teleost Sparus aurata.

    Science.gov (United States)

    Ruiz-Jarabo, Ignacio; Martos-Sitcha, J A; Barragán-Méndez, C; Martínez-Rodríguez, G; Mancera, J M; Arjona, F J

    2018-04-01

    In euryhaline teleosts, the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-interrenal axes (HPT and HPI, respectively) are regulated in response to environmental stimuli such as salinity changes. However, the molecular players participating in this physiological process in the gilthead seabream (Sparus aurata), a species of high value for aquaculture, are still not identified and/or fully characterized in terms of gene expression regulation. In this sense, this study identifies and isolates the thyrotropin-releasing hormone (trh) mRNA sequence from S. aurata, encoding prepro-Trh, the putative factor initiating the HPT cascade. In addition, the regulation of trh expression and of key brain genes in the HPI axis, i.e., corticotrophin-releasing hormone (crh) and corticotrophin-releasing hormone-binding protein (crhbp), was studied when the osmoregulatory status of S. aurata was challenged by exposure to different salinities. The deduced amino acid structure of trh showed 65-81% identity with its teleostean orthologs. Analysis of the tissue distribution of gene expression showed that trh mRNA is, though ubiquitously expressed, mainly found in brain. Subsequently, regulation of gene expression of trh, crh, and crhbp was characterized in fish acclimated to 5-, 15-, 40-, and 55-ppt salinities. In this regard, the brain gene expression pattern of trh mRNA was similar to that found for the crh gene, showing an upregulation of gene expression in seabream acclimated to the highest salinity tested. Conversely, crhbp did not change in any of the groups tested. Our results suggest that Trh and Crh play an important role in the acclimation of S. aurata to hypersaline environments.

  15. Novel teleost CD4-bearing cell populations provide insights into the evolutionary origins and primordial roles of CD4+ lymphocytes and CD4+ macrophages

    OpenAIRE

    Takizawa, Fumio; Magadan, Susana; Parra, David; Xu, Zhen; Koryt����, Tom����; Boudinot, Pierre; Sunyer, J. Oriol

    2016-01-01

    Tetrapods contain a single CD4 co-receptor with four immunoglobulin domains that likely arose from a primordial two-domain ancestor. Notably, teleost fish contain two CD4 genes. Like tetrapod CD4, CD4-1 of rainbow trout includes four immunoglobulin domains while CD4-2 contains only two. Since CD4-2 is reminiscent of the prototypic two-domain CD4 co-receptor, we hypothesized that by characterizing the cell types bearing CD4-1 and CD4-2, we would shed light into the evolution and primordial rol...

  16. Mobilization of retrotransposons as a cause of chromosomal diversification and rapid speciation: the case for the Antarctic teleost genus Trematomus.

    Science.gov (United States)

    Auvinet, J; Graça, P; Belkadi, L; Petit, L; Bonnivard, E; Dettaï, A; Detrich, W H; Ozouf-Costaz, C; Higuet, D

    2018-05-09

    The importance of transposable elements (TEs) in the genomic remodeling and chromosomal rearrangements that accompany lineage diversification in vertebrates remains the subject of debate. The major impediment to understanding the roles of TEs in genome evolution is the lack of comparative and integrative analyses on complete taxonomic groups. To help overcome this problem, we have focused on the Antarctic teleost genus Trematomus (Notothenioidei: Nototheniidae), as they experienced rapid speciation accompanied by dramatic chromosomal diversity. Here we apply a multi-strategy approach to determine the role of large-scale TE mobilization in chromosomal diversification within Trematomus species. Despite the extensive chromosomal rearrangements observed in Trematomus species, our measurements revealed strong interspecific genome size conservation. After identifying the DIRS1, Gypsy and Copia retrotransposon superfamilies in genomes of 13 nototheniid species, we evaluated their diversity, abundance (copy numbers) and chromosomal distribution. Four families of DIRS1, nine of Gypsy, and two of Copia were highly conserved in these genomes; DIRS1 being the most represented within Trematomus genomes. Fluorescence in situ hybridization mapping showed preferential accumulation of DIRS1 in centromeric and pericentromeric regions, both in Trematomus and other nototheniid species, but not in outgroups: species of the Sub-Antarctic notothenioid families Bovichtidae and Eleginopsidae, and the non-notothenioid family Percidae. In contrast to the outgroups, High-Antarctic notothenioid species, including the genus Trematomus, were subjected to strong environmental stresses involving repeated bouts of warming above the freezing point of seawater and cooling to sub-zero temperatures on the Antarctic continental shelf during the past 40 millions of years (My). As a consequence of these repetitive environmental changes, including thermal shocks; a breakdown of epigenetic regulation that

  17. Impacts of ocean acidification on respiratory gas exchange and acid-base balance in a marine teleost, Opsanus beta.

    Science.gov (United States)

    Esbaugh, Andrew J; Heuer, Rachael; Grosell, Martin

    2012-10-01

    The oceanic carbonate system is changing rapidly due to rising atmospheric CO(2), with current levels expected to rise to between 750 and 1,000 μatm by 2100, and over 1,900 μatm by year 2300. The effects of elevated CO(2) on marine calcifying organisms have been extensively studied; however, effects of imminent CO(2) levels on teleost acid-base and respiratory physiology have yet to be examined. Examination of these physiological processes, using a paired experimental design, showed that 24 h exposure to 1,000 and 1,900 μatm CO(2) resulted in a characteristic compensated respiratory acidosis response in the gulf toadfish (Opsanus beta). Time course experiments showed the onset of acidosis occurred after 15 min of exposure to 1,900 and 1,000 μatm CO(2), with full compensation by 2 and 4 h, respectively. 1,900-μatm exposure also resulted in significantly increased intracellular white muscle pH after 24 h. No effect of 1,900 μatm was observed on branchial acid flux; however, exposure to hypercapnia and HCO(3)(-) free seawater compromised compensation. This suggests branchial HCO(3)(-) uptake rather than acid extrusion is part of the compensatory response to low-level hypercapnia. Exposure to 1,900 μatm resulted in downregulation in branchial carbonic anhydrase and slc4a2 expression, as well as decreased Na(+)/K(+) ATPase activity after 24 h of exposure. Infusion of bovine carbonic anhydrase had no effect on blood acid-base status during 1,900 μatm exposures, but eliminated the respiratory impacts of 1,000 μatm CO(2). The results of the current study clearly show that predicted near-future CO(2) levels impact respiratory gas transport and acid-base balance. While the full physiological impacts of increased blood HCO(3)(-) are not known, it seems likely that chronically elevated blood HCO(3)(-) levels could compromise several physiological systems and furthermore may explain recent reports of increased otolith growth during exposure to elevated CO(2).

  18. Duplication of the IGFBP-2 gene in teleost fish: protein structure and functionality conservation and gene expression divergence.

    Directory of Open Access Journals (Sweden)

    Jianfeng Zhou

    Full Text Available BACKGROUND: Insulin-like growth factor binding protein-2 (IGFBP-2 is a secreted protein that binds and regulates IGF actions in controlling growth, development, reproduction, and aging. Elevated expression of IGFBP-2 is often associated with progression of many types of cancers. METHODOLOGY/PRINCIPAL FINDINGS: We report the identification and characterization of two IGFBP-2 genes in zebrafish and four other teleost fish. Comparative genomics and structural analyses suggest that they are co-orthologs of the human IGFBP-2 gene. Biochemical assays show that both zebrafish igfbp-2a and -2b encode secreted proteins that bind IGFs. These two genes exhibit distinct spatiotemporal expression patterns. During embryogenesis, IGFBP-2a mRNA is initially detected in the lens, then in the brain boundary vasculature, and subsequently becomes highly expressed in the liver. In the adult stage, liver has the highest levels of IGFBP-2a mRNA, followed by the brain. Low levels of IGFBP-2a mRNA were detected in muscle and in the gonad in male adults only. IGFBP-2b mRNA is detected initially in all tissues at low levels, but later becomes abundant in the liver. In adult males, IGFBP-2b mRNA is only detected in the liver. In adult females, it is also found in the gut, kidney, ovary, and muscle. To gain insights into how the IGFBP-2 genes may have evolved through partitioning of ancestral functions, functional and mechanistic studies were carried out. Expression of zebrafish IGFBP-2a and -2b caused significant decreases in the growth and developmental rates and their effects are comparable to that of human IGFBP-2. IGFBP-2 mutants with altered IGF binding-, RGD-, and heparin-binding sites were generated and their actions examined. While mutating the RGD and heparin binding sites had little effect, altering the IGF binding site abolished its biological activity. CONCLUSIONS/SIGNIFICANCE: These results suggest that IGFBP-2 is a conserved regulatory protein and it inhibits

  19. Vulnerability of teleosts caught by the pelagic tuna longline fleets in South Atlantic and Western Indian Oceans

    Science.gov (United States)

    Lucena-Frédou, Flávia; Kell, Laurie; Frédou, Thierry; Gaertner, Daniel; Potier, Michel; Bach, Pascal; Travassos, Paulo; Hazin, Fábio; Ménard, Frédéric

    2017-06-01

    Productivity and Susceptibility Analysis (PSA) is a methodology for evaluating the vulnerability of a stock based on its biological productivity and susceptibility to fishing. In this study, we evaluated the vulnerability of 60 stocks of tuna, billfishes and other teleosts caught by the tuna longline fleets operating in the South Atlantic and Indian Ocean using a semi-quantitative PSA. We (a) evaluated the vulnerability of the species in the study areas; (b) compared the vulnerability of target and non-target species and oceans; (c) analyzed the sensitivity of data entry; and (d) compared the results of the PSA to other fully quantitative assessment methods. Istiophoridae exhibited the highest scores for vulnerability. The top 10 species at risk were: Atlantic Istiophorus albicans; Indian Ocean Istiompax indica; Atlantic Makaira nigricans and Thunnus alalunga; Indian Ocean Xiphias gladius; Atlantic T. albacares, Gempylus serpens, Ranzania laevis and X. gladius; and Indian Ocean T. alalunga. All species considered at high risk were targeted or were commercialized bycatch, except for the Atlantic G. serpens and R. laevis which were discarded, and may be considered as a false positive. Those species and others at high risk should be prioritized for further assessment and/or data collection. Most species at moderate risk were bycatch species kept for sale. Conversely, species classified at low risk were mostly discarded. Overall, species at high risk were overfished and/or subjected to overfishing. Moreover, all species considered to be within extinction risk (Critically Endangered, Endangered and Vulnerable) were in the high-risk category. The good concordance between approaches corroborates the results of our analysis. PSA is not a replacement for traditional stock assessments, where a stock is assessed at regular intervals to provide management advice. It is of importance, however, where there is uncertainty about catches and life history parameters, since it can

  20. Characterization and comparison of fatty acyl Delta6 desaturase cDNAs from freshwater and marine teleost fish species.

    Science.gov (United States)

    Zheng, X; Seiliez, I; Hastings, N; Tocher, D R; Panserat, S; Dickson, C A; Bergot, P; Teale, A J

    2004-10-01

    Fish are the most important dietary source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), that have particularly important roles in human nutrition reflecting their roles in critical physiological processes. The objective of the study described here was to clone, functionally characterize and compare expressed fatty acid desaturase genes involved in the production of EPA and DHA in freshwater and marine teleost fish species. Putative fatty acid desaturase cDNAs were isolated and cloned from common carp (Cyprinus carpio) and turbot (Psetta maximus). The enzymic activities of the products of these cDNAs, together with those of cDNAs previously cloned from rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata), were determined by heterologous expression in the yeast Saccharomyces cerevisiae. The carp and turbot desaturase cDNAs included open reading frames (ORFs) of 1335 and 1338 base pairs, respectively, specifying proteins of 444 and 445 amino acids. The protein sequences possessed all the characteristic features of microsomal fatty acid desaturases, including three histidine boxes, two transmembrane regions, and N-terminal cytochrome b(5) domains containing the haem-binding motif, HPGG. Functional expression showed all four fish cDNAs encode basically unifunctional Delta6 fatty acid desaturase enzymes responsible for the first and rate-limiting step in the biosynthesis of HUFA from 18:3n-3 and 18:2n-6. All the fish desaturases were more active towards the n-3 substrate with 59.5%, 31.5%, 23.1% and 7.0% of 18:3n-3 being converted to 18:4n-3 in the case of turbot, trout, sea bream and carp, respectively. The enzymes also showed very low, probably physiologically insignificant, levels of Delta5 desaturase activity, but none of the products showed Delta4 desaturase activity. The cloning and characterization of desaturases from these fish is an important advance, as they are species in which

  1. Differential tissue distribution, developmental programming, estrogen regulation and promoter characteristics of cyp19 genes in teleost fish.

    Science.gov (United States)

    Callard, G V; Tchoudakova, A V; Kishida, M; Wood, E

    2001-12-01

    Teleost fish are characterized by exceptionally high levels of brain estrogen biosynthesis when compared to the brains of other vertebrates or to the ovaries of the same fish. Goldfish (Carassius auratus) and zebrafish (Danio rerio) have utility as complementary models for understanding the molecular basis and functional significance of exaggerated neural estrogen biosynthesis. Multiple cytochrome P450 aromatase (P450arom) cDNAs that derive from separate gene loci (cyp19a and cyp19b) are differentially expressed in brain (P450aromB>A) and ovary (P450aromA>B) and have a different developmental program (B>A) and response to estrogen upregulation (B only). As measured by increased P450aromB mRNA, a functional estrogen response system is first detected 24-48 h post-fertilization (hpf), consistent with the onset of estrogen receptor (ER) expression (alpha, beta, and gamma). The 5'-flanking region of the cyp19b gene has a TATA box, two estrogen response elements (EREs), an ERE half-site (ERE1/2), a nerve growth factor inducible-B protein (NGFI-B)/Nur77 responsive element (NBRE) binding site, and a sequence identical to the zebrafish GATA-2 gene neural specific enhancer. The cyp19a promoter region has TATA and CAAT boxes, a steroidogenic factor-1 (SF-1) binding site, and two aryl hydrocarbon receptor (AhR)/AhR nuclear translocator factor (ARNT) binding motifs. Both genes have multiple potential SRY/SOX binding sites (16 and 8 in cyp19b and cyp19a, respectively). Luciferase reporters have basal promoter activity in GH3 cells, but differences (a>b) are opposite to fish pituitary (b>a). When microinjected into fertilized zebrafish eggs, a cyp19b promoter-driven green fluorescent protein (GFP) reporter (but not cyp19a) is expressed in neurons of 30-48 hpf embryos, most prominently in retinal ganglion cells (RGCs) and their projections to optic tectum. Further studies are required to identify functionally relevant cis-elements and cellular factors, and to determine the

  2. Promoter characteristics of two cyp19 genes differentially expressed in the brain and ovary of teleost fish.

    Science.gov (United States)

    Tchoudakova, A; Kishida, M; Wood, E; Callard, G V

    2001-11-01

    Teleost fish are characterized by exceptionally high levels of neural estrogen biosynthesis when compared with the brains of other vertebrates or to the ovaries of the same fish. Two P450arom mRNAs which derive from separate gene loci (cyp19a and cyp19b) are differentially expressed in brain (b>a) and ovary (a>b) and have a different developmental program (b>a) and estrogen upregulation (b only). A polymerase chain reaction (PCR)-based genomic walking strategy was used to isolate the 5'-flanking regions of the goldfish (Carassius auratus) cyp19 genes. Sequence analysis of the cyp19b gene approximately 1.8 kb upstream of the transcription start site revealed a TATA box at nucleotide (nt) -30, two estrogen responsive elements (EREs; nt -351 and -211) and a consensus binding site (NBRE) for nerve growth factor inducible-B protein (NGFI-B/Nur77) at -286, which includes another ERE half-site. Also present were a sequence at nt -399 (CCCTCCT) required for neural specificity of the zebrafish GATA-2 gene, and 16 copies of an SRY/SOX binding motif. The 5'-flanking region ( approximately 1.0 kb) of the cyp19a gene had TATA (nt -48) and CAAT (nt -71) boxes, a steroidogenic factor-1 (SF-1) binding site (nt -265), eight copies of the SRY/SOX motif, and two copies of a recognition site for binding the arylhydrocarbon receptor (AhR)/AhR nuclear translocator factor (ARNT) heterodimer. Both genes had elements previously identified in the brain specific exon I promoter of the mouse aromatase gene. Cyp19a- and -b/luciferase constructs showed basal promoter activity in aromatase-expressing rodent pituitary (GH3) cells, but differences (a>b) did not reflect expression in fish pituitary in vivo (b>a), implying a lack of appropriate cell factors. Consistent with the onset of cyp19b expression in zebrafish embryos, microinjection of a green fluorescent protein (GFP) reporter plasmid into fertilized eggs revealed labeling in neural tissues at 30-48 h post-fertilization (hpf), most

  3. Lipovitellin-phosvitin crystals with orthorhombic features: thin-section electron microscopy, gel electrophoresis, and microanalysis in teleost and amphibian yolk platelets and a comparison with other vertebrates

    International Nuclear Information System (INIS)

    Lange, R.H.; Richter, H.P.; Riehl, R.; Zierold, K.; Trandaburu, T.; Magdowski, G.

    1983-01-01

    Yolk-platelet crystals in the teleosts Pelvicachromis pulcher and Noemacheilus barbatulus and the amphibians Xenopus laevis, Rana temporaria, R. esculenta, and Triturus sp. have been studied by electron diffraction and imaging using a standardized processing (glutaraldehyde-osmium tetroxide fixation, glutaraldehyde-urea embedding, thin-section staining), by X-ray microanalysis, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of their constituents. The crystal lattice is orthorhombic having. Crystal images in the three axial projections point to the presence of space group P212121 (or an approximation of it since the lipovitellin dimers cannot be fully equivalent in some cases), to differences between the phosvitins of the two teleosts, and to a highly unusual stain exclusion from large crystal constituents interpreted as representing lipovitellin dimers. Microanalysis in ultrathin cryosections and other preparations revealed K and Cl to be the prominent ions in the crystals (and in the superficial layer of the platelet). Gel electrophoresis (including data of cyclostomes) showed considerable molecular variations despite a closely similar crystal architecture, emphasizing a physiological significance of the architecture, which may have remained conserved for nearly 400 million years according to paleontologic views

  4. ERK, Akt, and STAT5 are differentially activated by the two growth hormone receptors subtypes of a teleost fish (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Jeffrey eKittilson

    2011-09-01

    Full Text Available Previously, we found that the teleost fish, rainbow trout, possesses two growth hormone receptor (GHR subtypes that display distinct ligand binding and agonist-induced regulation features. In this study, we used Chinese hamster ovary-K1 cells stably transfected individually with the two trout GHR subtypes, GHR1 and GHR2, to elucidate receptor-effector pathway linkages. Growth hormone (GH stimulated rapid (5-10 min phosphorylation of ERK, Akt, JAk2, and STAT5 in both GHR1- and GHR2-expressing cells; however; STAT5 was activated to a greater extent through GHR1 than through GHR2, whereas ERK and Akt were activated to a greater through GHR2 than through GHR1. Although blockade of the ERK pathway had no effect on the activation of Akt, inhibition of PI3k-Akt partially prevented activation of ERK, suggesting cross-talk between the ERK and PI3K-Akt pathways. JAK2 inhibition completely blocked activation of ERK, Akt, and STAT5, suggesting that all of these pathways link to GHR1 and GHR2 via JAK2. These findings establish important receptor-effector pathway linkages and suggest that the GHR subtypes of teleost fish may be functionally distinct.

  5. Alternative Pre-mRNA Splicing in Mammals and Teleost Fish: A Effective Strategy for the Regulation of Immune Responses Against Pathogen Infection.

    Science.gov (United States)

    Chang, Ming Xian; Zhang, Jie

    2017-07-15

    Pre-mRNA splicing is the process by which introns are removed and the protein coding elements assembled into mature mRNAs. Alternative pre-mRNA splicing provides an important source of transcriptome and proteome complexity through selectively joining different coding elements to form mRNAs, which encode proteins with similar or distinct functions. In mammals, previous studies have shown the role of alternative splicing in regulating the function of the immune system, especially in the regulation of T-cell activation and function. As lower vertebrates, teleost fish mainly rely on a large family of pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs) from various invading pathogens. In this review, we summarize recent advances in our understanding of alternative splicing of piscine PRRs including peptidoglycan recognition proteins (PGRPs), nucleotide binding and oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) and their downstream signaling molecules, compared to splicing in mammals. We also discuss what is known and unknown about the function of splicing isoforms in the innate immune responses against pathogens infection in mammals and teleost fish. Finally, we highlight the consequences of alternative splicing in the innate immune system and give our view of important directions for future studies.

  6. The effect of perfusion and irrigation flow rate variations on NaCl efflux from the isolated, perfused head of the marine teleost, Myoxocephalus octodecimspinosus

    International Nuclear Information System (INIS)

    Claiborne, J.B.; Evans, D.H.

    1981-01-01

    In vivo branchial blood pressure and unidirectional efflux values for NaCl were determined in the marine teleost, Myoxocephalus octodecimspinosus. Utilizing an isolated, perfused head preparation, perfused at in vivo pressure levels, NaCl efflux was measured and compared to in vivo values. The effect of variations in perfusion or irrigation rates on the ion efflux across the gills of the isolated head was also studied. The efflux of 22 Na from the isolated, perfused head was found to be similar to in vivo values and dependent on perfusion flow and pressure. In vitro 36 Cl efflux was lower than the efflux from intact animals and was determined to be flow/pressure independent. Irrigation rate changes at all rates tested did not affect the unidirectional efflux of either ion. (Auth.)

  7. Effect of perfusion and irrigation flow rate variations on NaCl efflux from the isolated, perfused head of the marine teleost, Myoxocephalus octodecimspinosus

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, J.B. (Miami Univ., Coral Gables, FL (USA)); Evans, D.H. (Mt. Desert Island Biological Laboratory, Salsbury Cove, ME, USA)

    1981-06-01

    In vivo branchial blood pressure and unidirectional efflux values for NaCl were determined in the marine teleost, Myoxocephalus octodecimspinosus. Utilizing an isolated, perfused head preparation, perfused at in vivo pressure levels, NaCl efflux was measured and compared to in vivo values. The effect of variations in perfusion or irrigation rates on the ion efflux across the gills of the isolated head was also studied. The efflux of /sup 22/Na from the isolated, perfused head was found to be similar to in vivo values and dependent on perfusion flow and pressure. In vitro /sup 36/Cl efflux was lower than the efflux from intact animals and was determined to be flow/pressure independent. Irrigation rate changes at all rates tested did not affect the unidirectional efflux of either ion.

  8. Acidic digestion in a teleost: postprandial and circadian pattern of gastric pH, pepsin activity, and pepsinogen and proton pump mRNAs expression.

    Science.gov (United States)

    Yúfera, Manuel; Moyano, Francisco J; Astola, Antonio; Pousão-Ferreira, Pedro; Martínez-Rodríguez, Gonzalo

    2012-01-01

    Two different modes for regulation of stomach acid secretion have been described in vertebrates. Some species exhibit a continuous acid secretion maintaining a low gastric pH during fasting. Others, as some teleosts, maintain a neutral gastric pH during fasting while the hydrochloric acid is released only after the ingestion of a meal. Those different patterns seem to be closely related to specific feeding habits. However, our recent observations suggest that this acidification pattern could be modified by changes in daily feeding frequency and time schedule. The aim of this study was to advance in understanding the regulation mechanisms of stomach digestion and pattern of acid secretion in teleost fish. We have examined the postprandial pattern of gastric pH, pepsin activity, and mRNA expression for pepsinogen and proton pump in white seabream juveniles maintained under a light/dark 12/12 hours cycle and receiving only one morning meal. The pepsin activity was analyzed according to the standard protocol buffering at pH 2 and using the actual pH measured in the stomach. The results show how the enzyme precursor is permanently available while the hydrochloric acid, which activates the zymogen fraction, is secreted just after the ingestion of food. Results also reveal that analytical protocol at pH 2 notably overestimates true pepsin activity in fish stomach. The expression of the mRNA encoding pepsinogen and proton pump exhibited almost parallel patterns, with notable increases during the darkness period and sharp decreases just before the morning meal. These results indicate that white seabream uses the resting hours for recovering the mRNA stock that will be quickly used during the feeding process. Our data clearly shows that both daily illumination pattern and feeding time are involved at different level in the regulation of the secretion of digestive juices.

  9. Acidic digestion in a teleost: postprandial and circadian pattern of gastric pH, pepsin activity, and pepsinogen and proton pump mRNAs expression.

    Directory of Open Access Journals (Sweden)

    Manuel Yúfera

    Full Text Available Two different modes for regulation of stomach acid secretion have been described in vertebrates. Some species exhibit a continuous acid secretion maintaining a low gastric pH during fasting. Others, as some teleosts, maintain a neutral gastric pH during fasting while the hydrochloric acid is released only after the ingestion of a meal. Those different patterns seem to be closely related to specific feeding habits. However, our recent observations suggest that this acidification pattern could be modified by changes in daily feeding frequency and time schedule. The aim of this study was to advance in understanding the regulation mechanisms of stomach digestion and pattern of acid secretion in teleost fish. We have examined the postprandial pattern of gastric pH, pepsin activity, and mRNA expression for pepsinogen and proton pump in white seabream juveniles maintained under a light/dark 12/12 hours cycle and receiving only one morning meal. The pepsin activity was analyzed according to the standard protocol buffering at pH 2 and using the actual pH measured in the stomach. The results show how the enzyme precursor is permanently available while the hydrochloric acid, which activates the zymogen fraction, is secreted just after the ingestion of food. Results also reveal that analytical protocol at pH 2 notably overestimates true pepsin activity in fish stomach. The expression of the mRNA encoding pepsinogen and proton pump exhibited almost parallel patterns, with notable increases during the darkness period and sharp decreases just before the morning meal. These results indicate that white seabream uses the resting hours for recovering the mRNA stock that will be quickly used during the feeding process. Our data clearly shows that both daily illumination pattern and feeding time are involved at different level in the regulation of the secretion of digestive juices.

  10. Actions of sex steroids on kisspeptin expression and other reproduction-related genes in the brain of the teleost fish European sea bass.

    Science.gov (United States)

    Alvarado, M V; Servili, A; Molés, G; Gueguen, M M; Carrillo, M; Kah, O; Felip, A

    2016-11-01

    Kisspeptins are well known as mediators of the coordinated communication between the brain-pituitary axis and the gonads in many vertebrates. To test the hypothesis that gonadal steroids regulate kiss1 and kiss2 mRNA expression in European sea bass (a teleost fish), we examined the brains of gonad-intact (control) and castrated animals, as well as castrated males (GDX) and ovariectomized females (OVX) that received testosterone (T) and estradiol (E 2 ) replacement, respectively, during recrudescence. In GDX males, low expression of kiss1 mRNA is observed by in situ hybridization in the caudal hypothalamus (CH) and the mediobasal hypothalamus (MBH), although hypothalamic changes in kiss1 mRNA levels were not statistically different among the groups, as revealed by real-time PCR. However, T strongly decreased kiss2 expression levels in the hypothalamus, which was documented in the MBH and the nucleus of the lateral recess (NRLd) in GDX T-treated sea bass males. Conversely, it appears that E 2 evokes low kiss1 mRNA in the CH, while there were cells expressing kiss2 in the MBH and NRLd in these OVX females. These results demonstrate that kisspeptin neurons are presumably sensitive to the feedback actions of sex steroids in the sea bass, suggesting that the MBH represents a major site for sex steroid actions on kisspeptins in this species. Also, recent data provide evidence that both positive and negative actions occur in key factors involved in sea bass reproductive function, including changes in the expression of gnrh-1/gonadotropin, cyp19b, er and ar genes and sex steroid and gonadotropin plasma levels in this teleost fish. © 2016. Published by The Company of Biologists Ltd.

  11. Reprint of "Current perspectives on the androgen 5 alpha-dihydrotestosterone (DHT) and 5 alpha-reductases in teleost fishes and amphibians".

    Science.gov (United States)

    Martyniuk, Christopher J; Bissegger, Sonja; Langlois, Valérie S

    2014-07-01

    The androgen 5 alpha-dihydrotestosterone (DHT) is a steroidogenic metabolite that has received little attention in non-mammalian species. DHT is produced by the reduction of the double-bond of testosterone by a group of enzymes called 5 alpha-reductases of which there can be multiple isoforms (i.e., srd5a1, srd5a2, and srd5a3). Data from amphibians suggest that the expression of the srd5a genes occurs in early development, and continues until adulthood; however insufficient data exist in fish species, where DHT is thought to be relatively biologically inactive. Here, we demonstrate that fathead minnow (FHM; Pimephales promelas) developing embryos and adults express srd5a enzyme isoforms. During FHM embryogenesis, both srd5a1 and srd5a3 mRNA levels were significantly correlated in expression levels while srd5a2 showed a more unique pattern of expression. In adult FHMs, males had significantly higher levels of srd5a2 in the liver and gonad compared to females. In the male and female liver, transcript levels for srd5a2 were more abundant compared to srd5a1 and srd5a3, suggesting a prominent role for srd5a2 in this tissue. Interestingly, the ovary expressed higher mRNA levels of srd5a3 than the testis. Thus, data suggest that srd5a isoforms can show sexually dimorphic expression patterns in fish. We also conducted a literature review of the biological effects observed in embryonic and adult fish and amphibians after treatments with DHT and DHT-related compounds. Treatments with DHT in teleost fishes and amphibians have resulted in unexpected biological responses that are characteristic of both androgens and anti-androgens. For example, in fish DHT can induce vitellogenin in vitro from male and female hepatocytes and can increase 17β-estradiol production from the teleost ovary. We propose, that to generate further understanding of the roles of DHT in non-mammals, studies are needed that (1) address how DHT is synthesized within tissues of fish and amphibians; (2

  12. The evolution and appearance of C3 duplications in fish originate an exclusive teleost c3 gene form with anti-inflammatory activity.

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    Gabriel Forn-Cuní

    Full Text Available The complement system acts as a first line of defense and promotes organism homeostasis by modulating the fates of diverse physiological processes. Multiple copies of component genes have been previously identified in fish, suggesting a key role for this system in aquatic organisms. Herein, we confirm the presence of three different previously reported complement c3 genes (c3.1, c3.2, c3.3 and identify five additional c3 genes (c3.4, c3.5, c3.6, c3.7, c3.8 in the zebrafish genome. Additionally, we evaluate the mRNA expression levels of the different c3 genes during ontogeny and in different tissues under steady-state and inflammatory conditions. Furthermore, while reconciling the phylogenetic tree with the fish species tree, we uncovered an event of c3 duplication common to all teleost fishes that gave rise to an exclusive c3 paralog (c3.7 and c3.8. These paralogs showed a distinct ability to regulate neutrophil migration in response to injury compared with the other c3 genes and may play a role in maintaining the balance between inflammatory and homeostatic processes in zebrafish.

  13. FLUCTUATING ASYMMETRY IN THE OTOLITH WIDTH AND LENGTH OF ADULT TELEOST (Beryx splendens LOWE, 1834 (FAMILY: BERCIDAE COLLECTED FROM THE ARABIAN SEA COASTS OF SULTANATE OF OMAN

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    H.K. Albusaidi

    2010-10-01

    Full Text Available Fluctuating asymmetry was described for the otolith width and length of adult teleost Beryx splendens. The results showed that the level of asymmetry of the otolith width was the highest among the two asymmetry values obtained for the otolith of B. splendens. For the otolith width character, the results showed that the level of asymmetry at its highest value in fish ranging in length between 191–200 mm and in its lowest value in fish ranging in length between 121–180 mm. For the otolith length, the highest value of asymmetry is noticed in fish ranging in length between 231–244 mm and the lowest value in fish within the length of 121–190 mm. The possible cause of the asymmetry in this species has been discussed in relation to different pollutants and their presence in the area. No trend of increase in the asymmetry values with the fish length was noticed for the otolith width, but there is a weak trend of increase with the fish length in case of otolith length character.

  14. A study of the uptake and toxicity of some stable and radioactive pollutants in marine organisms: antimony, silver, cobalt and strontium in mollusks, crustaceans and teleosts

    International Nuclear Information System (INIS)

    Amiard, J.-C.

    1978-10-01

    Qualitative and quantitative results following direct aquatic contamination of mollusks, crustaceans and teleosts by 125 Sb, 110 Ag, 60 Co, 85 Sr are reported. The effects of a number of biotic and abiotic parameters on the contamination of the various organisms and the distribution and elimination of the radionuclides in the tissues were investigated. The transfer of sup(110m)Ag, 60 Co and 125 Sb was studied in several benthic food chains. The transfer factor (F.T.) between a given trophic level and the initial environment (seawater) was determined as well as various physiological parameters (percentages ingested, assimilated, eliminated via the feces or urine and/or the gills. Elimination and tissue uptake were followed in mollusks and crustaceans. The consequences of contamination by stable and radioactive pollutants on plants and animals were considered. Acute (lethal) toxicity of various metals or metalloids on marine organisms were quantified. More sensitive sublethal tests considering physiological functions or behaviour were used. Irradiation doses to experiment animals were calculated, showing the importance of the (internal or external distribution of radionuclides and individual geometries on the total exposure dose [fr

  15. PSA-NCAM expression in the teleost optic tectum is related to ecological niche and use of vision in finding food.

    Science.gov (United States)

    Labak, I; Pavić, V; Zjalić, M; Blažetić, S; Viljetić, B; Merdić, E; Heffer, M

    2017-08-01

    In this study, tangential migration and neuronal connectivity organization were analysed in the optic tectum of seven different teleosts through the expression of polysialylated neural cell adhesion molecule (PSA-NCAM) in response to ecological niche and use of vision. Reduced PSA-NCAM expression in rainbow trout Oncorhynchus mykiss optic tectum occurred in efferent layers, while in pike Esox lucius and zebrafish Danio rerio it occurred in afferent and efferent layers. Zander Sander lucioperca and European eel Anguilla anguilla had very low PSA-NCAM expression in all tectal layers except in the stratum marginale. Common carp Cyprinus carpio and wels catfish Silurus glanis had the same intensity of PSA-NCAM expression in all tectal layers. The optic tectum of all studied fishes was also a site of tangential migration with sustained PSA-NCAM and c-series ganglioside expression. Anti-c-series ganglioside immunoreactivity was observed in all tectal layers of all analysed fishes, even in layers where PSA-NCAM expression was reduced. Since the optic tectum is indispensable for visually guided prey capture, stabilization of synaptic contact and decrease of neurogenesis and tangential migration in the visual map are an expected adjustment to ecological niche. The authors hypothesize that this stabilization would probably be achieved by down-regulation of PSA-NCAM rather than c-series of ganglioside. © 2017 The Fisheries Society of the British Isles.

  16. A mannose-specific tetrameric lectin with mitogenic and antibacterial activities from the ovary of a teleost, the cobia (Rachycentron canadum).

    Science.gov (United States)

    Ngai, Patrick H K; Ng, T B

    2007-02-01

    A tetrameric lectin, with hemagglutinating activity toward rabbit erythrocytes and with specificity toward D-mannosamine and D(+)-mannose, was isolated from the ovaries of a teleost, the cobia Rachycentron canadum. The isolation protocol comprised ion exchange chromatography on CM-cellulose and Q-Sepharose, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono Q, and finally gel filtration by FPLC on Superose 12. The lectin was adsorbed on all ion exchangers used. It exhibited a molecular mass of 180 kDa in gel filtration on Superose 12 and a single 45-kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is a tetrameric protein. The hemagglutinating activity of the lectin was stable up to 40 degrees C and between pH 4 and pH 10. All hemagglutinating activity disappeared at 60 degrees C and at pH 1 and pH 13. The hemagglutinating activity was doubled in the presence of 0.1 microM FeCl3. The lectin exerted antibacterial activity against Escherichia coli with 50% inhibition at 250 microg. There was no antifungal activity toward Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, and Rhizoctonia solani at a dose of 300 microg. The lectin exhibited maximal mitogenic response from mouse splenocytes at a concentration of 14 microM.

  17. Acid-base responses to feeding and intestinal Cl- uptake in freshwater- and seawater-acclimated killifish, Fundulus heteroclitus, an agastric euryhaline teleost.

    Science.gov (United States)

    Wood, Chris M; Bucking, Carol; Grosell, Martin

    2010-08-01

    Marine teleosts generally secrete basic equivalents (HCO(3)(-)) and take up Na(+) and Cl(-) in the intestine so as to promote absorption of H(2)O. However, neither the integration of these functions with feeding nor the potential role of the gut in ionoregulation and acid-base balance in freshwater have been well studied. The euryhaline killifish (Fundulus heteroclitus) is unusual in lacking both an acid-secreting stomach and a mechanism for Cl(-) uptake at the gills in freshwater. Responses to a satiation meal were evaluated in both freshwater- and seawater-acclimated killifish. In intact animals, there was no change in acid or base flux to the external water after the meal, in accord with the absence of any post-prandial alkaline tide in the blood. Indeed, freshwater animals exhibited a post-prandial metabolic acidosis ('acidic tide'), whereas seawater animals showed no change in blood acid-base status. In vitro gut sac experiments revealed a substantially higher rate of Cl(-) absorption by the intestine in freshwater killifish, which was greatest at 1-3 h after feeding. The Cl(-) concentration of the absorbate was higher in preparations from freshwater animals than from seawater killifish and increased with fasting. Surprisingly, net basic equivalent secretion rates were also much higher in preparations from freshwater animals, in accord with the 'acidic tide'; in seawater preparations, they were lowest after feeding and increased with fasting. Bafilomycin (1 micromol l(-1)) promoted an 80% increase in net base secretion rates, as well as in Cl(-) and fluid absorption, at 1-3 h post-feeding in seawater preparations only, explaining the difference between freshwater and seawater fish. Preparations from seawater animals at 1-3 h post-feeding also acidified the mucosal saline, and this effect was associated with a marked rise in P(CO(2)), which was attenuated by bafilomycin. Measurements of chyme pH from intact animals confirmed that intestinal fluid (chyme) pH and

  18. Toxicological perspective on the osmoregulation and ionoregulation physiology of major ions by freshwater animals: Teleost fish, crustacea, aquatic insects, and Mollusca.

    Science.gov (United States)

    Griffith, Michael B

    2017-03-01

    Anthropogenic sources increase freshwater salinity and produce differences in constituent ions compared with natural waters. Moreover, ions differ in physiological roles and concentrations in intracellular and extracellular fluids. Four freshwater taxa groups are compared, to investigate similarities and differences in ion transport processes and what ion transport mechanisms suggest about the toxicity of these or other ions in freshwater. Although differences exist, many ion transporters are functionally similar and may belong to evolutionarily conserved protein families. For example, the Na + /H + -exchanger in teleost fish differs from the H + /2Na + (or Ca 2+ )-exchanger in crustaceans. In osmoregulation, Na + and Cl - predominate. Stenohaline freshwater animals hyperregulate until they are no longer able to maintain hypertonic extracellular Na + and Cl - concentrations with increasing salinity and become isotonic. Toxic effects of K + are related to ionoregulation and volume regulation. The ionic balance between intracellular and extracellular fluids is maintained by Na + /K + -adenosine triphosphatase (ATPase), but details are lacking on apical K + transporters. Elevated H + affects the maintenance of internal Na + by Na + /H + exchange; elevated HCO 3 - inhibits Cl - uptake. The uptake of Mg 2+ occurs by the gills or intestine, but details are lacking on Mg 2+ transporters. In unionid gills, SO 4 2- is actively transported, but most epithelia are generally impermeant to SO 4 2- . Transporters of Ca 2+ maintain homeostasis of dissolved Ca 2+ . More integration of physiology with toxicology is needed to fully understand freshwater ion effects. Environ Toxicol Chem 2017;36:576-600. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the

  19. TGF-β1 exerts opposing effects on grass carp leukocytes: implication in teleost immunity, receptor signaling and potential self-regulatory mechanisms.

    Directory of Open Access Journals (Sweden)

    Mu Yang

    Full Text Available In fish immunity, the regulatory role of transforming growth factor-β1 (TGF-β1 has not been fully characterized. Here we examined the immunoregulatory effects of TGF-β1 in grass carp peripheral blood leukocytes (PBL and head kidney leukocytes (HKL. It is interesting that TGF-β1 consistently stimulated the cell viability and the mRNA levels of pro-inflammatory cytokines (Tnfα and Ifnγ and T/B cell markers [Cd4-like (Cd4l, Cd8α, Cd8β and Igμ] in PBL, which contrasted with its inhibitory tone in HKL. Further studies showed that grass carp TGF-β1 type I receptor, activin receptor-like kinase 5 (ALK5, was indispensable for the immunoregulatory effects of TGF-β1 in PBL and HKL. Notably, TGF-β1 persistently attenuated ALK5 expression, whereas immunoneutralization of endogenous grass carp TGF-β1 could increase ALK5 mRNA and protein levels. It is consistent with the observation that TGF-β1 decreased the number of ALK5(+ leukocytes in PBL and HKL, revealing a negative regulation of TGF-β1 signaling at the receptor level. Moreover, transient treatment with TGF-β1 for 24 h was sufficient to induce similar cellular responses compared with the continuous treatment. This indicated a possible mechanism by which TGF-β1 triggered the down-regulation of ALK5 mRNA and protein, leading to the desensitization of grass carp leukocytes toward TGF-β1. Accordingly, our data revealed a dual role of TGF-β1 in teleost immunity in which it can serve as a positive or negative control device and provided additional mechanistic insights as to how TGF-β1 controls its signaling in vertebrate leukocytes.

  20. Effect of taurine supplementation on hepatic metabolism and alleviation of cadmium toxicity and bioaccumulation in a marine teleost, red sea bream, Pagrus major.

    Science.gov (United States)

    Hano, Takeshi; Ito, Katsutoshi; Kono, Kumiko; Ito, Mana; Ohkubo, Nobuyuki; Mochida, Kazuhiko

    2017-02-01

    This study was performed to unravel the mechanism of the beneficial action of taurine on marine teleost fish, red sea bream (Pagrus major), by analyzing the hepatic metabolism. Moreover, the ameliorative effects of the nutrient against cadmium toxicity and bioaccumulation were further evaluated. The fish were fed a diet containing 0 % (TAU0 %), 0.5 % (TAU0.5 %), or 5.0 % (TAU5.0 %) taurine for 40-55 days (d) and subjected to cadmium acute toxicity and bioaccumulation tests. Taurine deficiency in feed severely affected growth and the hepatic metabolic profiles of the fish, including a remarkable increase in myo-inositol, aspartate, and ß-alanine in the TAU0 % group, which indicates a complementary physiological response to taurine deficiency. For the acute toxicity test, fish were fed the test diets for 55 d and were then exposed to different dose of cadmium ranging from 0 to 5.6 mg/L for 96 h. Fish fed taurine had a higher tolerance to cadmium than those not fed taurine. For the bioaccumulation test, fish were fed the test diets for 40 d and then were chronically exposed to 0.2 mg/L of cadmium for 28 d followed by depuration for 21 d. Cadmium concentrations in the liver and muscle of fish fed TAU5.0 % were significantly lower than those of fish fed TAU0 % for the first 7 d of exposure and the first 7 d of elimination. Our findings suggest a possible mechanism for the beneficial role played by taurine and that the inclusion of taurine in fish aquaculture feed may reduce cadmium contamination of fish intended for human consumption.

  1. Structural and functional characterization of salmon STAT1, STAT2 and IRF9 homologs sheds light on interferon signaling in teleosts

    Directory of Open Access Journals (Sweden)

    Mehrdad Sobhkhez

    2014-01-01

    Full Text Available Mammalian IRF9 and STAT2, together with STAT1, form the ISGF3 transcription factor complex, which is critical for type I interferon (IFN-induced signaling, while IFNγ stimulation is mediated by homodimeric STAT1 protein. Teleost fish are known to possess most JAK and STAT family members, however, description of their functional activity in lower vertebrates is still scarce. In the present study we have identified two different STAT2 homologs and one IRF9 homolog from Atlantic salmon (Salmo salar. Both proteins have domain-like structures with functional motifs that are similar to higher vertebrates, suggesting that they are orthologs to mammalian STAT2 and IRF9. The two identified salmon STAT2s, named STAT2a and STAT2b, showed high sequence identity but were divergent in their transactivation domain (TAD. Like STAT1, ectopically expressed STAT2a and b were shown to be tyrosine phosphorylated by type I IFNs and, interestingly, also by IFNγ. Microscopy analyses demonstrated that STAT2 co-localized with STAT1a in the cytoplasm of unstimulated cells, while IFNa1 and IFNγ stimulation seemed to favor their nuclear localization. Overexpression of STAT2a or STAT2b together with STAT1a activated a GAS-containing reporter gene construct in IFNγ-stimulated cells. The highest induction of GAS promoter activation was found in IFNγ-stimulated cells transfected with IRF9 alone. Taken together, these data suggest that salmon STAT2 and IRF9 may have a role in IFNγ-induced signaling and promote the expression of GAS-driven genes in bony fish. Since mammalian STAT2 is primarily an ISGF3 component and not involved in IFNγ signaling, our finding features a novel role for STAT2 in fish.

  2. A novel soluble immune-type receptor (SITR in teleost fish: carp SITR is involved in the nitric oxide-mediated response to a protozoan parasite.

    Directory of Open Access Journals (Sweden)

    Carla M S Ribeiro

    2011-01-01

    Full Text Available The innate immune system relies upon a wide range of germ-line encoded receptors including a large number of immunoglobulin superfamily (IgSF receptors. Different Ig-like immune receptor families have been reported in mammals, birds, amphibians and fish. Most innate immune receptors of the IgSF are type I transmembrane proteins containing one or more extracellular Ig-like domains and their regulation of effector functions is mediated intracellularly by distinct stimulatory or inhibitory pathways.Carp SITR was found in a substracted cDNA repertoire from carp macrophages, enriched for genes up-regulated in response to the protozoan parasite Trypanoplasma borreli. Carp SITR is a type I protein with two extracellular Ig domains in a unique organisation of a N-proximal V/C2 (or I- type and a C-proximal V-type Ig domain, devoid of a transmembrane domain or any intracytoplasmic signalling motif. The carp SITR C-proximal V-type Ig domain, in particular, has a close sequence similarity and conserved structural characteristics to the mammalian CD300 molecules. By generating an anti-SITR antibody we could show that SITR protein expression was restricted to cells of the myeloid lineage. Carp SITR is abundantly expressed in macrophages and is secreted upon in vitro stimulation with the protozoan parasite T. borreli. Secretion of SITR protein during in vivo T. borreli infection suggests a role for this IgSF receptor in the host response to this protozoan parasite. Overexpression of carp SITR in mouse macrophages and knock-down of SITR protein expression in carp macrophages, using morpholino antisense technology, provided evidence for the involvement of carp SITR in the parasite-induced NO production.We report the structural and functional characterization of a novel soluble immune-type receptor (SITR in a teleost fish and propose a role for carp SITR in the NO-mediated response to a protozoan parasite.

  3. A comparative assessment of the adrenotoxic effects of cadmium in two teleost species, rainbow trout, Oncorhynchus mykiss, and yellow perch, Perca flavescens

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, Alexandra; Hontela, Alice

    2004-03-30

    Rainbow trout (Oncorhynchus mykiss) and yellow perch (Perca flavescens) have a different sensitivity to cadmium (Cd) in vivo (troutteleosts. Adrenocortical cells were exposed to Cd for 60 min, then stimulated with ACTH, dbcAMP or with pregnenolone, a cortisol precursor. Cd inhibited ACTH-stimulated cortisol secretion in a dose-dependent manner in both fish species, however, the EC50s (concentration resulting in 50% inhibition of cortisol secretion) was significantly lower in trout (EC50=0.09 mM) than perch (EC50=0.26 mM). To test the specificity of Cd to act as an endocrine disrupter, the LC50 (concentration that kills 50% of the cells) was also evaluated to determine the LC50/EC50 ratio (LC50/EC50{sub O.mykiss}=175.6>LC50/EC50{sub P.flavescens}=37.7). Adrenocortical cells of trout were more sensitive than those of perch and Cd had a higher endocrine-disrupting potential and specificity in trout than in perch. However, in both species, Cd had the same effect on ACTH, dbcAMP and pregnenolone-stimulated cortisol secretion, with pregnenolone maintaining cortisol secretion until cell viability was impaired. These results confirm that for both species, Cd interferes in the signalling pathway of cortisol synthesis in a step prior to the pregnenolone formation. Data provided by the present study revealed important differences in vulnerability of adrenal steroidogenesis between rainbow trout and yellow perch.

  4. Sequence and Expression Analysis of Interferon Regulatory Factor 10 (IRF10 in Three Diverse Teleost Fish Reveals Its Role in Antiviral Defense.

    Directory of Open Access Journals (Sweden)

    Qiaoqing Xu

    Full Text Available Interferon regulatory factor (IRF 10 was first found in birds and is present in the genome of other tetrapods (but not humans and mice, as well as in teleost fish. The functional role of IRF10 in vertebrate immunity is relatively unknown compared to IRF1-9. The target of this research was to clone and characterize the IRF10 genes in three economically important fish species that will facilitate future evaluation of this molecule in fish innate and adaptive immunity.In the present study, a single IRF10 gene was cloned in grass carp Ctenopharyngodon idella and Asian swamp eel Monopterus albus, and two, named IRF10a and IRF10b, in rainbow trout Oncorhynchus mykiss. The fish IRF10 molecules share highest identities to other vertebrate IRF10s, and have a well conserved DNA binding domain, IRF-associated domain, and an 8 exon/7 intron structure with conserved intron phase. The presence of an upstream ATG or open reading frame (ORF in the 5'-untranslated region of different fish IRF10 cDNA sequences suggests potential regulation at the translational level, and this has been verified by in vitro transcription/translation experiments of the trout IRF10a cDNA, but would still need to be validated in fish cells.Both trout IRF10 paralogues are highly expressed in thymus, blood and spleen but are relatively low in head kidney and caudal kidney. Trout IRF10b expression is significantly higher than IRF10a in integumentary tissues i.e. gills, scales, skin, intestine, adipose fin and tail fins, suggesting that IRF10b may be more important in mucosal immunity. The expression of both trout IRF10 paralogues is up-regulated by recombinant IFN-γ. The expression of the IRF10 genes is highly induced by Poly I:C in vitro and in vivo, and by viral infection, but is less responsive to peptidoglycan and bacterial infection, suggesting an important role of fish IRF10 in antiviral defense.

  5. Developmental expression of the G protein-coupled receptor 54 and three GnRH mRNAs in the teleost fish cobia.

    Science.gov (United States)

    Mohamed, J Shaik; Benninghoff, Abby D; Holt, G Joan; Khan, Izhar A

    2007-02-01

    The cDNAs of the G protein-coupled receptor 54 (GPR54) and three prepro-gonadotropin-releasing hormones, GnRH-I (seabream GnRH), GnRH-II (chicken GnRH-II), and GnRH-III (salmon GnRH) were isolated and cloned from the brain of the teleost fish cobia, Rachycentron canadum. The cobia GPR54 cDNA was 95 and 51-56% identical to those of tilapia and mammalian models respectively. The GnRH cDNA sequences of cobia showed strong identities to those of tilapia, Atlantic croaker, red drum, and the seabass and seabream species. The real-time quantitative RT-PCR methods allowed detection of all three GnRH mRNAs on the first day after hatching (DAH). The GnRH-I mRNA levels, which were the lowest among the three GnRHs, increased gradually with two distinct peaks in larvae at 3 and 4 DAH. On the other hand, GnRH-II and GnRH-III mRNAs were significantly higher in larvae at 2 and 6 DAH compared with those on the preceding days. In addition, significant peaks of all the three GnRH mRNAs were observed in the brains of 26-day-old fish. The finding of higher GnRH-I and GnRH-II mRNAs in males than females at 153 DAH may be related to early puberty observed during the first year in laboratory-reared male cobia. Moreover, this study demonstrates for the first time the expression of GPR54 mRNA during larval development in a vertebrate species. The concomitant expression patterns of GPR54 and GnRH mRNAs during different stages of larval and juvenile developments, and during early puberty in male cobia suggest a potential relationship between GPR54 and multiple GnRHs during these stages of development consistent with the role of GPR54 in controlling GnRH release in mammals. The increase in GPR54 and GnRH mRNAs observed during early puberty in cobia is consistent with a similar change reported in pubertal rats. This finding together with the localization of GPR54 mRNAs on GnRH neurons in fish and mammals suggests that the GPR54-GnRH interactions may be conserved in different vertebrate groups.

  6. Differential effects of cortisol and 11-deoxycorticosterone on ion transport protein mRNA levels in gills of two euryhaline teleosts, Mozambique tilapia (Oreochromis mossambicus) and striped bass (Morone saxatilis).

    Science.gov (United States)

    Kiilerich, Pia; Tipsmark, Christian K; Borski, Russell J; Madsen, Steffen S

    2011-04-01

    The role of cortisol as the only corticosteroid in fish osmoregulation has recently been challenged with the discovery of a mineralocorticoid-like hormone, 11-deoxycorticosterone (DOC), and necessitates new studies of the endocrinology of osmoregulation in fish. Using an in vitro gill explant incubation approach, DOC-mediated regulation of selected osmoregulatory target genes in the gill was investigated and compared with that of cortisol in two euryhaline teleosts, Mozambique tilapia (Oreochromis mossambicus) and striped bass (Morone saxatilis). The effects were tested in gills from both fresh water (FW)- and seawater (SW)-acclimated fish. Both cortisol and DOC caused an up-regulation of the Na(+),K(+)-ATPase α1 subunit in SW-acclimated tilapia but had no effect in FW-acclimated fish. Cortisol conferred an increase in Na(+),K(+),2Cl(-) cotransporter (NKCC) isoform 1a transcript levels in FW- and SW-acclimated tilapia, whereas DOC had a stimulatory effect only in SW-acclimated fish. Cortisol had no effect on NKCC isoform 1b mRNA levels at both salinities, while DOC stimulated this isoform in SW-acclimated fish. In striped bass, cortisol conferred an up-regulation of Na(+),K(+)-ATPase α1 and NKCC transcript levels in FW- and SW-acclimated fish, whereas DOC resulted in down-regulation of these transcripts in FW-acclimated fish. It was also found that both corticosteroids may rapidly (30 min) alter the mitogen-activated protein kinase signalling pathway in gill, inducing phosphorylation of extracellular signal-regulated kinase 1 (ERK1) and ERK2 in a salinity-dependent manner. The study shows a disparate organisation of corticosteroid signalling mechanisms involved in ion regulation in the two species and adds new evidence to a role of DOC as a mineralocorticoid hormone in teleosts.

  7. Differences in Ca2+-management between the ventricle of two species of neotropical teleosts: the jeju, Hoplerythrinus unitaeniatus (Spix & Agassiz, 1829, and the acara, Geophagus brasiliensis (Quoy & Gaimard, 1824

    Directory of Open Access Journals (Sweden)

    Monica Jones Costa

    Full Text Available This study analyzed the physiological role of the cardiac sarcoplasmic reticulum (SR of two neotropical teleosts, the jeju, Hoplerythrinus unitaeniatus (Erythrinidae, and the acara, Geophagus brasiliensis (Cichlidae. While the in vivo heart frequency (fH - bpm of acara (79.6 ± 6.6 was higher than that of the jeju (50.3 ± 2.7, the opposite was observed for the ventricular inotropism (Fc - mN/mm² at 12 bpm (acara = 28.66 ± 1.86 vs. jeju = 36.09 ± 1.67. A 5 min diastolic pause resulted in a strong potentiation of Fc (≅ 90% of strips from jeju, which was completely abolished by ryanodine. Ryanodine also resulted in a ≅ 20% decrease in the Fc developed by strips from jeju at both subphysiological (12 bpm and physiological (in vivo frequencies. However, this effect of ryanodine reducing the Fc from jeju was completely compensated by adrenaline increments (10-9 and 10-6 M. In contrast, strips from acara were irresponsive to ryanodine, irrespective of the stimulation frequency, and increases in adrenaline concentration (to 10-9 and 10-6 M further increased Fc. These results reinforce the hypothesis of the functionality of the SR as a common trait in neotropical ostariophysian (as jeju, while in acanthopterygians (as acara it seems to be functional mainly in 'athletic' species.

  8. [Proceedings of the 5th Symposium on Mesozoic and Cenozoic Decapod Crustaceans, Krakow, Poland, 2013: A tribute to Pál Mihály Müller / R.H.B. Fraaije, M. Hyžný, J.W.M. Jagt, M. Krobicki & B.W.M. van Bakel (eds.)]: Neozanthopsis americana (Decapoda, Brachyura, Carpilioidea) from the Middle Eocene Cane River Formation of Louisiana, USA, and associated teleost otoliths

    NARCIS (Netherlands)

    Schweitzer, C.E.; Feldmann, R.M.; Stringer, G.L.

    2014-01-01

    A large collection of Neozanthopsis americana (Rathbun, 1928) from the Middle Eocene (Lutetian) Cane River Formation in Louisiana, USA, represents the first opportunity to describe the species in detail. Detailed analysis of associated teleost otoliths and other vertebrate remains documents a

  9. Assessment of spermatogenesis and plasma sex steroids in a seasonal breeding teleost: a comparative study in an area of influence of a tributary, downstream from a hydroelectric power dam, Brazil.

    Science.gov (United States)

    Domingos, Fabricio F T; Thomé, Ralph G; Arantes, Fabio P; Castro, Antonio Carlos S; Sato, Yoshimi; Bazzoli, Nilo; Rizzo, Elizete

    2012-12-01

    River damming and building of hydroelectric power plants interrupt the reproductive migration routes and change the major physicochemical parameters of water quality, with drastic consequences for populations of migratory fishes. The goal of this study was to evaluate proliferation and cell death during spermatogenesis and serum profiles of sex steroids in Prochilodus argenteus, from the São Francisco River, downstream from the Três Marias Dam. A total of 257 adult males were caught quarterly during a reproductive cycle in two sites: the first 34 km of the river after the dam (site 1) and the second 34-54 km after the dam (site 2), after the confluence with a tributary, the Abaeté River. Seasonal changes in the testicular activity associated with morphometric analyses of germ cells as well as proliferation and testicular apoptosis support a more active spermatogenesis in fish from site 2, where higher levels of sex steroids and gonadosomatic index (GSI) were also found. In site 1, fish presented low serum levels of testosterone, 17β-estradiol and 17α-hydroxyprogesterone and a low GSI during gonadal maturation. Spermatogonial proliferation (PCNA) and apoptosis (TUNEL) were more elevated in fish from site 1, but spermatocytes were mainly labelled in fish from site 2. Overall, these data demonstrate changes in testicular activity and plasma sex steroids in a neotropical teleost fish living downstream from a hydroelectric dam, supplying new data on fish reproduction in regulated rivers. Moreover, morphometric analyses associated with sex steroids profiles provide reliable tools to assess fish spermatogenesis under environmental stress conditions.

  10. Adaptation of teleosts to very high salinity

    DEFF Research Database (Denmark)

    Laverty, Gary; Skadhauge, Erik

    2012-01-01

    (-), which ultimately drives the overall process of NaCl secretion. Balance studies of intake and output clearly indicate that a decrease in the osmotic permeability of the gill epithelium must also occur. The molecular correlates of this effect are not known, although decreased expression of one or more...... with intestinal water absorption and with the properties of the gill epithelium. While there is much that is still not completely understood, recent work has begun to look at these adaptations at the cellular and molecular level. As with seawater osmoregulation, fish adapting to hypersaline conditions generally...

  11. The remarkable reproductive diversity of teleost fishes

    Czech Academy of Sciences Publication Activity Database

    Smith, Carl; Wootton, R. J.

    2016-01-01

    Roč. 17, č. 4 (2016), s. 1208-1215 ISSN 1467-2960 Institutional support: RVO:68081766 Keywords : Hermaphroditism * mating system * self-fertilization * sex determination * unisexuality * viviparity Subject RIV: EG - Zoology Impact factor: 9.013, year: 2016

  12. Teleosts in hypoxia : Aspects of anaerobic metabolism

    NARCIS (Netherlands)

    Van den Thillart, G.; van Waarde, Aren

    1985-01-01

    Moderate hypoxia can be tolerated by many fish species, while only some species survive severe hypoxia or anoxia. Hypoxia usually activates anaerobic glycolysis, which may be temporary when the animals are able to improve their oxygen extraction capacity. Switching over to aerobic metabolism allows

  13. Nerve endings in the heart of teleosts.

    Science.gov (United States)

    Kumar, S

    1979-01-01

    The nerve endings in the heart of fishes were studied using silver impregnation techniques. The heart chambers are profusely innervated by the sympathetic, parasympathetic (vagal) and postganglionic fibers of the intracardiac ganglia situated at the sinuatrial and the atrioventricular junctions. The plexuses are composed of medullated and nonmedullated fibers. The nerve fibers generally end freely and are slightly branched or unbranched terminations of myelinated and unmyelinated fibers. Moreover, a few nerve fibers end redundant in the form of end-rings, bulb-like, bush-like, club-shaped end end-coil like structures. The complex unencapsulated types of endings are also found in the myocardium of the atrium and the ventricle. The encapsulated endings (Vater-Pacinian; Krause end-bulb) could not be observed.

  14. Ancestral and derived attributes of the dlx gene repertoire, cluster structure and expression patterns in an African cichlid fish

    Directory of Open Access Journals (Sweden)

    Renz Adina J

    2011-01-01

    Full Text Available Abstract Background Cichlid fishes have undergone rapid, expansive evolutionary radiations that are manifested in the diversification of their trophic morphologies, tooth patterning and coloration. Understanding the molecular mechanisms that underlie the cichlids' unique patterns of evolution requires a thorough examination of genes that pattern the neural crest, from which these diverse phenotypes are derived. Among those genes, the homeobox-containing Dlx gene family is of particular interest since it is involved in the patterning of the brain, jaws and teeth. Results In this study, we characterized the dlx genes of an African cichlid fish, Astatotilapia burtoni, to provide a baseline to later allow cross-species comparison within Cichlidae. We identified seven dlx paralogs (dlx1a, -2a, -4a, -3b, -4b, -5a and -6a, whose orthologies were validated with molecular phylogenetic trees. The intergenic regions of three dlx gene clusters (dlx1a-2a, dlx3b-4b, and dlx5a-6a were amplified with long PCR. Intensive cross-species comparison revealed a number of conserved non-coding elements (CNEs that are shared with other percomorph fishes. This analysis highlighted additional lineage-specific gains/losses of CNEs in different teleost fish lineages and a novel CNE that had previously not been identified. Our gene expression analyses revealed overlapping but distinct expression of dlx orthologs in the developing brain and pharyngeal arches. Notably, four of the seven A. burtoni dlx genes, dlx2a, dlx3b, dlx4a and dlx5a, were expressed in the developing pharyngeal teeth. Conclusion This comparative study of the dlx genes of A. burtoni has deepened our knowledge of the diversity of the Dlx gene family, in terms of gene repertoire, expression patterns and non-coding elements. We have identified possible cichlid lineage-specific changes, including losses of a subset of dlx expression domains in the pharyngeal teeth, which will be the targets of future functional

  15. Rapid behavioral and genomic responses to social opportunity.

    Directory of Open Access Journals (Sweden)

    Sabrina S Burmeister

    2005-11-01

    Full Text Available From primates to bees, social status regulates reproduction. In the cichlid fish Astatotilapia (Haplochromis burtoni, subordinate males have reduced fertility and must become dominant to reproduce. This increase in sexual capacity is orchestrated by neurons in the preoptic area, which enlarge in response to dominance and increase expression of gonadotropin-releasing hormone 1 (GnRH1, a peptide critical for reproduction. Using a novel behavioral paradigm, we show for the first time that subordinate males can become dominant within minutes of an opportunity to do so, displaying dramatic changes in body coloration and behavior. We also found that social opportunity induced expression of the immediate-early gene egr-1 in the anterior preoptic area, peaking in regions with high densities of GnRH1 neurons, and not in brain regions that express the related peptides GnRH2 and GnRH3. This genomic response did not occur in stable subordinate or stable dominant males even though stable dominants, like ascending males, displayed dominance behaviors. Moreover, egr-1 in the optic tectum and the cerebellum was similarly induced in all experimental groups, showing that egr-1 induction in the anterior preoptic area of ascending males was specific to this brain region. Because egr-1 codes for a transcription factor important in neural plasticity, induction of egr-1 in the anterior preoptic area by social opportunity could be an early trigger in the molecular cascade that culminates in enhanced fertility and other long-term physiological changes associated with dominance.

  16. A study of the morphology of the gills of an extreme alkalinity and hyperosmotic adapted teleost Oreochromis alcalicus grahami (Boulenger) with particular emphasis on the ultrastructure of the chloride cells and their modifications with water dilution. A SEM and TEM study.

    Science.gov (United States)

    Maina, J N

    1990-01-01

    The general gill morphology of Oreochromis alcalicus grahami, a teleost adapted to high salinity and hyperosmosis, is basically similar to that of other teleostean fish. The species has four pairs of gill arches, all of which have well developed filaments. Each of the arches (holobranchs) has two rows of filaments (hemibranchs). Bilaterally situated secondary lamellae branch from the central axis of the filaments. The lamellae reach their maximum size at the middle of the filament, gradually decrease in size and eventually disappear towards the tip of the filament, which is bare. The leading edge of the gill filament and the immediate interlamellar space is covered by a stratified epithelium consisting of pavement cells, mucous cells, chloride cells and undifferentiated cells. The surface of these cells is made up of concentric microridges. The chloride cells were found only on the primary epithelium (filamental epithelium) and very rarely on the secondary epithelium (lamellar epithelium). Two types of chloride cells were observed in the gills of Oreochromis. The superficial chloride cells have fewer mitochondria concentrated towards the basal aspect of the cell, and a network of tubules towards the apical surface and are less electron dense. These cells intercommunicate with the water through an apical pore. The deep chloride cells have numerous diffuse mitochondria intercalated between a fine profuse tubular network and are more electron dense. These cells are covered by one or more layers of pavement cells and thus do not have access to the external surface. After gradual dilution of the lake water in which the fish were kept, both types of chloride cells remained topographically and ultrastructurally distinct. However, in both kinds of cell the mitochondria decreased in number and size. Initially there was an increase in the diameter and the degree of interdigitation of the tubules followed by a gradual decrease. An increase in the quantity of rough endoplasmic

  17. Homologs of CD83 from elasmobranch and teleost fish.

    Science.gov (United States)

    Ohta, Yuko; Landis, Eric; Boulay, Thomas; Phillips, Ruth B; Collet, Bertrand; Secombes, Chris J; Flajnik, Martin F; Hansen, John D

    2004-10-01

    Dendritic cells are one of the most important cell types connecting innate and adaptive immunity, but very little is known about their evolutionary origins. To begin to study dendritic cells from lower vertebrates, we isolated and characterized CD83 from the nurse shark (Ginglymostoma cirratum (Gici)) and rainbow trout (Oncorhynchus mykiss (Onmy)). The open reading frames for Gici-CD83 (194 aa) and Onmy-CD83 (218 aa) display approximately 28-32% identity to mammalian CD83 with the presence of two conserved N-linked glycosylation sites. Identical with mammalian CD83 genes, Gici-CD83 is composed of five exons including conservation of phase for the splice sites. Mammalian CD83 genes contain a split Ig superfamily V domain that represents a unique sequence feature for CD83 genes, a feature conserved in both Gici- and Onmy-CD83. Gici-CD83 and Onmy-CD83 are not linked to the MHC, an attribute shared with mouse but not human CD83. Gici-CD83 is expressed rather ubiquitously with highest levels in the epigonal tissue, a primary site for lymphopoiesis in the nurse shark, whereas Onmy-CD83 mRNA expression largely paralleled that of MHC class II but at lower levels. Finally, Onmy-CD83 gene expression is up-regulated in virus-infected trout, and the promoter is responsive to trout IFN regulatory factor-1. These results suggest that the role of CD83, an adhesion molecule for cell-mediated immunity, has been conserved over 450 million years of vertebrate evolution.

  18. LIPID CONTENT AND CONDITION IN AN ESTUARINE TELEOST

    African Journals Online (AJOL)

    The value of lipid content as a measure of the feeding level of fish compared with condition factor was assessed using two ... in fish are stored at or near the sites of utilization since there is no specialized adipose tissue as in birds and mammals. ..... The behaviour and physiology of herring and other clupeids. Adv. mar. Bioi.

  19. Mechanistic basis of otolith formation during teleost inner ear development.

    Science.gov (United States)

    Wu, David; Freund, Jonathan B; Fraser, Scott E; Vermot, Julien

    2011-02-15

    Otoliths, which are connected to stereociliary bundles in the inner ear, serve as inertial sensors for balance. In teleostei, otolith development is critically dependent on flow forces generated by beating cilia; however, the mechanism by which flow controls otolith formation remains unclear. Here, we have developed a noninvasive flow probe using optical tweezers and a viscous flow model in order to demonstrate how the observed hydrodynamics influence otolith assembly. We show that rotational flow stirs and suppresses precursor agglomeration in the core of the cilia-driven vortex. The velocity field correlates with the shape of the otolith and we provide evidence that hydrodynamics is actively involved in controlling otolith morphogenesis. An implication of this hydrodynamic effect is that otolith self-assembly is mediated by the balance between Brownian motion and cilia-driven flow. More generally, this flow feature highlights an alternative biological strategy for controlling particle localization in solution. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Impacts of Low Temperature on the Teleost Immune System

    Directory of Open Access Journals (Sweden)

    Quinn H. Abram

    2017-11-01

    Full Text Available As poikilothermic vertebrates, fish can experience changes in water temperature, and hence body temperature, as a result of seasonal changes, migration, or efflux of large quantities of effluent into a body of water. Temperature shifts outside of the optimal temperature range for an individual fish species can have negative impacts on the physiology of the animal, including the immune system. As a result, acute or chronic exposure to suboptimal temperatures can impair an organisms’ ability to defend against pathogens and thus compromise the overall health of the animal. This review focuses on the advances made towards understanding the impacts of suboptimal temperature on the soluble and cellular mediators of the innate and adaptive immune systems of fishes. Although cold stress can result in varying effects in different fish species, acute and chronic suboptimal temperature exposure generally yield suppressive effects, particularly on adaptive immunity. Knowledge of the effects of environmental temperature on fish species is critical for both the optimal management of wild species and the best management practices for aquaculture species.

  1. Timing reproduction in teleost fish: cues and mechanisms

    Science.gov (United States)

    Juntti, Scott A; Fernald, Russell D

    2016-01-01

    Fish comprise half of extant vertebrate species and use a rich variety of reproductive strategies that have yielded insights into the basic mechanisms that evolved for sex. To maximize the chances of fertilization and survival of offspring, fish species time reproduction to occur at optimal times. For years, ethologists have performed painstaking experiments to identify sensory inputs and behavioral outputs of the brain during mating. Here we review known mechanisms that generate sexual behavior, focusing on the factors that govern the timing of these displays. The development of new technologies, including high-throughput sequencing and genome engineering, have the potential to provide novel insights into how the vertebrate brain consummates mating at the appropriate time. PMID:26952366

  2. Unique molecular properties of superoxide dismutase from teleost fish skin.

    Science.gov (United States)

    Nakano, T; Sato, M; Takeuchi, M

    1995-02-27

    A unique Cu,Zn-SOD was found and isolated from plaice Paralichthys olivaceus skin. Surprisingly, the properties of purified fish skin SOD were very different from those of SOD from other sources reported so far. The purified SOD was composed of four same subunits of 16 kDa and the molecular weight of the native SOD was found to be around 65 kDa. The dominant amino acids of the SOD were Ser, Thr, Pro and Glu. Above 70 degrees C, thermostability of the SOD was much lower than that of bovine erythrocyte Cu,Zn-SOD.

  3. Current knowledge on the melatonin system in teleost fish.

    Science.gov (United States)

    Falcón, J; Migaud, H; Muñoz-Cueto, J A; Carrillo, M

    2010-02-01

    Melatonin is a much conserved feature in vertebrates that plays a central role in the entrainment of daily and annual physiological rhythms. Investigations aiming at understanding how melatonin mediates the effects of photoperiod on crucial functions and behaviors have been very active in the last decades, particularly in mammals. In fish a clear-cut picture is still missing. Here we review the available data on (i) the sites of melatonin production in fish, (ii) the mechanisms that control its daily and annual rhythms of production and (iii) the characterization of its different receptor subtypes, their location and regulation. The in vivo and in vitro data on melatonin effects on crucial neuroendocrine regulations, including reproduction, growth, feeding and behavioral responses, are also reviewed. Finally we discuss how manipulation of the photic cues impact on fish circannual clock and annual cycle of reproduction, and how this can be used for aquaculture purposes. Copyright 2009 Elsevier Inc. All rights reserved.

  4. Juveniles, food and the surf zone habitat: implications for teleost ...

    African Journals Online (AJOL)

    The length composition, abundance patterns and feeding habits of ... recorded off King's Beach only the aforementioned species ..... Christensen (1978) gives the distribution of the streepie, .... plankton in the surf zone and inshore waters of the Eastern .... abundance and diversity of the Swartkops estuary ichthyofauna.

  5. Nongenomic actions of cortisol in the teleost lactotroph model

    DEFF Research Database (Denmark)

    Borski, Russell J; Tipsmark, Christian Kølbæk; Mita, M

    2006-01-01

    of the present study was to investigate the role of phospholipase C (PLC)-IP3 in mediating cortisol's actions. During 30 min and 4-hour incubation, chicken GnRH-II induces a 2-4 fold increase in PRL release from the tilapia pituitary. The stimulatory effect of cGnRH-II was reduced by cortisol, cortisol-21......-hemisuccinate (HEF) and its membrane impermeant analog, HEF-BSA. Since GnRH induces PRL release, in part, via activation of PLC this suggests that cortisol may rapidly inhibit GnRH-induced PRL release by suppressing PLC activity. We also found that cortisol rapidly inhibits IP3 accumulation in tilapia RPD under...... stimulation by angiotensin II, a factor known to exert its cellular effects through stimulation of the PLC-IP3 pathway. Further studies demonstrate that cortisol reduces PLC activity (measured by the hydrolysis of 3H-PIP2) in a dose dependent manner from crude tilapia lactotroph membrane preparations. SRIF...

  6. Toxicological effects of arsenic exposure in a freshwater teleost fish ...

    African Journals Online (AJOL)

    High concentration of arsenic in groundwater in the north-eastern states of India has become a major cause of concern. Inorganic arsenic of geological origin is found in groundwater used as drinking-water in several parts of the world. Arsenic is used in various industries and agriculture and excessive arsenic finds its way ...

  7. Thyroid hormone actions on male reproductive system of teleost fish.

    Science.gov (United States)

    Tovo-Neto, Aldo; da Silva Rodrigues, Maira; Habibi, Hamid R; Nóbrega, Rafael Henrique

    2018-04-17

    Thyroid hormones (THs) play important roles in the regulation of many biological processes of vertebrates, such as growth, metabolism, morphogenesis and reproduction. An increasing number of studies have been focused on the involvement of THs in the male reproductive system of vertebrates, in particular of fish. Therefore, this mini-review aims to summarize the main findings on THs role in male reproductive system of fish, focusing on sex differentiation, testicular development and spermatogenesis. The existing data in the literature have demonstrated that THs exert their roles at the different levels of the hypothalamic-pituitary-gonadal (HPG) axis. In general a positive correlation has been shown between THs and fish reproductive status; where THs are associated with testicular development, growth and maturation. Recently, the molecular mechanisms underlying the role of THs in spermatogenesis have been unraveled in zebrafish testis. THs promote germ cell proliferation and differentiation by increasing a stimulatory growth factor of spermatogenesis produced by Sertoli cells. In addition, THs enhanced the gonadotropin-induced androgen release in zebrafish testis. Next to their functions in the adult testis, THs are involved in the gonadal sex differentiation through modulating sex-related gene expression, and testicular development via regulation of Sertoli cell proliferation. In conclusion, this mini-review showed that THs modulate the male reproductive system during the different life stages of fish. The physiological and molecular mechanisms showed a link between the thyroid and reproduction, suggesting a possibly co-evolution and interdependence of these two systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Intestinal bicarbonate secretion by marine teleost fish - why and how?

    DEFF Research Database (Denmark)

    Wilson, Rod W.; Wilson, Jonathan M.; Grosell, Martin Hautopp

    2002-01-01

    Calcium, Precipitation, Osmoregulation, pH-stat titration, Water absorption, Chloride-bicarbonate exchange......Calcium, Precipitation, Osmoregulation, pH-stat titration, Water absorption, Chloride-bicarbonate exchange...

  9. Intestinal glucose transport and salinity adaptation in a euryhaline teleost

    International Nuclear Information System (INIS)

    Reshkin, S.J.; Ahearn, G.A.

    1987-01-01

    Glucose transport by upper and lower intestinal brush-border membrane vesicles of the African tilapia (Oreochromis mossambicus) was characterized in fish acclimated to either freshwater of full-strength sea water. D-[ 3 H]-glucose uptake by vesicles was stimulated by a transmembrane Na gradient, was electrogenic, and was enhanced by countertransport of either D-glucose or D-galactose. Glucose transport was greater in the upper intestine than in the lower intestine and in sea water animals rather than in fish acclimated to freshwater. Glucose influx (10-s uptake) involved both saturable and nonsaturable transport components. Sea water adaptation increased apparent glucose influx K/sub t/, J/sub max/, apparent diffusional permeability (P), and the apparent Na affinity of the cotransport system in both intestinal segments, but the stoichiometry of Na-glucose transfer (1:1) was unaffected by differential saline conditions or gut region. It is suggested that increased sugar transport in sea water animals is due to the combination of enhanced Na-binding properties and an increase in number or transfer rate of the transport proteins. Freshwater animals compensate for reduced Na affinity of the coupled process by markedly increasing the protein affinity for glucose

  10. Identification of multiple FXYD genes in a teleost fish

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Madsen, Steffen

    2007-01-01

    It is increasingly clear, that alterations in Na+,K+-ATPase kinetics to fit the demands in specialized cell types is vital for the enzyme to execute its different physiological roles in diverse tissues. In addition to tissue dependent expression of isoforms of the conventional subunits, and a and ß...... the tissue dependent expression of the different isoforms in gill, kidney, intestine, heart, muscle, brain and liver. When inspecting the relative expression levels we found, that while two isoforms were detected at comparable levels in several of the examined tissues, 6 isoforms were expressed in a more...... discrete manner. In excitatory tissues, two isoforms were highly expressed in brain and one in skeletal muscle. In osmoregulatory tissues, one isoform was expressed predominantly in gill, one in kidney and one equally in kidney and intestine. We observed that expression of several FXYD genes in kidney...

  11. Embryonic adaptations and nutrition in the viviparous teleost Clinus ...

    African Journals Online (AJOL)

    The boxes were sealed with masking tape, placed in black photographic bags and stored in a refrigerator at 4°C for a period of ten days before being developed. ... Balzers Union CPD 010 critical point dryer, using the carbon dioxide fluid-replacement method. Dried specimens were transferred to specimen holders,.

  12. The cranial cartilages of teleosts and their classification.

    OpenAIRE

    Benjamin, M

    1990-01-01

    The structure and distribution of cartilages has been studied in 45 species from 24 families. The resulting data have been used as a basis for establishing a new classification. A cartilage is regarded as 'cell-rich' if its cells or their lacunae occupy more than half of the tissue volume. Five classes of cell-rich cartilage are recognised (a) hyaline-cell cartilage (common in the lips of bottom-dwelling cyprinids) and its subtypes fibro/hyaline-cell cartilage, elastic/hyaline-cell cartilage ...

  13. Geometry and mechanics of teleost gastrulation and the formation of primary embryonic axes.

    Science.gov (United States)

    Cherdantseva, Elena M; Cherdantsev, Vladimir G

    2006-01-01

    Examination of normal shaping dynamics and immediate and long-term responses to blastoderm cutting in zebrafish and loach embryos prior to the onset of gastrulation and during the course of epiboly revealed that anteroposterior (AP) and dorsoventral (DV) polarity formation is connected with shaping of the blastoderm circumferential region, which stretches along and shrinks across its movement axes and originates the non-isotropic fields of tensile stresses. Based on data from cutting experiments and quantitative morphology, we reconstructed the movement-shaping patterns of epiboly and embryonic shield formation. We revealed that AP and DV axes originate as a mass cell movement subject to the movement-shaping equivalence principle, which means the spatial series of differently shaped areas corresponding to the time succession of the same area shaping. Maintenance of the main body axes in orthogonal orientation depends on the mechanical equilibrium principle allowing for converting shape asymmetry into that of tensile stresses and vice versa. The causal relationship between the main movement-shaping axes and that of embryonic polarity was proved in cutting experiments in which the DV axis direction was subject to rearrangement so as to adjust to the new direction of mass cell movement axes induced by healing the wound in the blastoderm circumferential region.

  14. Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Thaís Heloisa Vaz Farias

    2016-05-01

    Full Text Available Abstract: The present study aimed to evaluate the effects of Na heparin and Na2EDTA on blood of Piaractus mesopotamicus (360.7±42.4g, 26.4±1.0cm. Twenty fishes were sampled in two experiment trials, ten for erythrocyte fragility analysis and ten for hematologic and plasma biochemical study. The blood collected by venous-caudal puncture was fractioned and stored in anticoagulants solution: Na2EDTA 10%, Na2EDTA 3%, Na heparin 5000 IU and Na heparin 100 IU. Plasmatic levels of calcium presented in the Na2EDTA stored samples were about 80% lower than both heparin groups. Blood samples of P. mesopotamicus stored with Na2EDTA demonstrated increase in the hematocrit and MCV, and decrease in MCHC. The dose-response effect was observed in this study. The results are reinforced by the higher levels of plasmatic protein and hemolysis presented in the Na2EDTA 10% stored blood, confirming the deleterious effect of this anticoagulant treatment on the quality of blood samples. Na2EDTA is not indicated to store P. mesopotamicus blood samples, but sodium heparin at 100 IU is the most recommended anticoagulant, since this treatment presented the lower rate of alterations in the stored blood.

  15. Retrograde trafficking of tracer protein by the internal ovarian epithelium in gravid goodeid teleosts.

    Science.gov (United States)

    Schindler, J F

    1990-02-01

    Gravid goodeid females harbor embryos in a preformed ovarian cavity for prolonged periods of gestation. Various nutrients for embryonic growth are provided by the internal ovarian epithelium (IOE). Its cells flatten during late stages of gestation and form an attenuated layer of cytoplasm covering a dense network of protruding capillaries, with the nuclear domains mostly recessing between the vascular meshes. The IOE in both Xenotoca eiseni and Girardinichthys viviparus exhibit morphological features associated with vesicular transport of macromolecules. The amounts of rough endoplasmic reticulum in the IOE cells seem insufficient to effectively synthesise proteinaceous secretions. Apparently, it rather serves as a transit route for serum-derived products. Cationized ferritin (CF) was injected into the ovarian cavity of gravid females. The electrostatic ligand spotwise attached to the luminal surface of the IOE and gained access by adsorptive micropinocytosis. Many tracer molecules were sequestered into lysosome-like vacuoles that became increasingly swollen after prolonged incubation intervals. In addition, CF traversed the IOE within small vesicles. At the basal pole of the cells the contents of transcytotic vesicles were evacuated, and localization of small CF-clusters was regularly in the basement lamina, in the underlying connective tissue, in vacuoles within migrant cells, in vesicular compartments of the capillary endothelia, in capillary lumina, and in intravascular leucocytes. Tracer molecules were never observed to enter stacked Golgi cisternae. Since the cationic marker probably follows retrograde pathways of the protein secretion, the experimental data support the morphologically derived conclusions that postulate a major role for the IOE in transepithelial transport.

  16. Stress and stress disorders in a teleost fish, the common carp Cyprinus carpio L.

    NARCIS (Netherlands)

    Ruane, N.M.

    2002-01-01

    Unlike research using mammalian animal models such as rats or mice, experimental fish often come from wild or commercial sources, leading to a lack of well defined experimental animal models. Isogenic carp offer us a well defined fish model for physiological research. The aim of this thesis

  17. Steroidogenesis in ovarian tissue of a viviparous teleost, the guppy Poecilia reticulata

    NARCIS (Netherlands)

    Lambert, J.G.D.; Pot, M.G.E.

    1975-01-01

    1. 1. Homogenates of ovaries of 3- and 12-month-old guppies were incubated with pregnenolone-7α-3H and progesterone-4-14C, and with androstenedione-1,2-3H, respectively. 2. 2. From the double-labeled experiment, 17α-hydroxypregnenolone, 17α-hydroxyprogesterone, dehydroepiandrosterone,

  18. Stereology as a tool to assess reproduction strategy and fecundity of teleost fishes

    DEFF Research Database (Denmark)

    Bucholtz, Rikke Hagstrøm

    methods to assess fecundity and reproductive strategies. The strength of the stereological method being that, in combination with conventional histological analysis, quantification of all oocyte categories is possible, as well as registration of qualitative characteristics relating to spawning history...... of oocyte dynamics in fish and were successfully implemented in herring ovaries for quantification of both oocyte numbers and sizes as well as total volume fraction of atretic oocytes, introducing a negligible error to the total variance of estimates. The histological nature of the stereological methods...... facilitated a ready validation of maturity data, distinguishing first time spawners from repeat spawners, as well as a ready recognition of ongoing oocyte recruitment in early maturity stages, early stage atresia, POFs and residual eggs. Analyzing a sample of females all collected during a short time frame...

  19. Costimulatory receptors in a teleost fish: Typical CD28, elusive CTLA4

    Science.gov (United States)

    Bernard, D.; Riteau, B.; Hansen, J.D.; Phillips, R.B.; Michel, F.; Boudinot, P.; Benmansour, A.

    2006-01-01

    T cell activation requires both specific recognition of the peptide-MHC complex by the TCR and additional signals delivered by costimulatory receptors. We have identified rainbow trout sequences similar to CD28 (rbtCD28) and CTLA4 (rbtCTLA4). rbtCD28 and rbtCTLA4 are composed of an extracellular Ig-superfamily V domain, a transmembrane region, and a cytoplasmic tail. The presence of a conserved ligand binding site within the V domain of both molecules suggests that these receptors likely recognize the fish homologues of the B7 family. The mRNA expression pattern of rbtCD28 and rbtCTLA4 in naive trout is reminiscent to that reported in humans and mice, because rbtCTLA4 expression within trout leukocytes was quickly up-regulated following PHA stimulation and virus infection. The cytoplasmic tail of rbtCD28 possesses a typical motif that is conserved in mammalian costimulatory receptors for signaling purposes. A chimeric receptor made of the extracellular domain of human CD28 fused to the cytoplasmic tail of rbtCD28 promoted TCR-induced IL-2 production in a human T cell line, indicating that rbtCD28 is indeed a positive costimulator. The cytoplasmic tail of rtrtCTLA4 lacked obvious signaling motifs and accordingly failed to signal when fused to the huCD28 extracellular domain. Interestingly, rbtCTLA4 and rbtCD28 are not positioned on the same chromosome and thus do not belong to a unique costimulatory cluster as in mammals. Finally, oar results raise questions about the origin and evolution of positive and negative costimulation in vertebrate immune systems. Copyright ?? 2006 by The American Association of Immunologists, Inc.

  20. Physiological roles of tryptophan in teleosts: current knowledge and perspectives for future studies

    DEFF Research Database (Denmark)

    Hoseini, Seyyed Morteza; Pérez-Jiménez, Amelia; Costas, Benjamin

    2017-01-01

    from the neuroendocrine to the immune system in vertebrates. In aquaculture, extensive research has been performed to optimize the levels of tryptophan in the commercial diets for many fish species. Providing adequate levels of this amino acid is critically important for fish growth but also for fish...

  1. Carbon dioxide induced plasticity of branchial acid-base pathways in an estuarine teleost

    Science.gov (United States)

    Allmon, Elizabeth B.; Esbaugh, Andrew J.

    2017-04-01

    Anthropogenic CO2 is expected to drive ocean pCO2 above 1,000 μatm by 2100 - inducing respiratory acidosis in fish that must be corrected through branchial ion transport. This study examined the time course and plasticity of branchial metabolic compensation in response to varying levels of CO2 in an estuarine fish, the red drum, which regularly encounters elevated CO2 and may therefore have intrinsic resilience. Under control conditions fish exhibited net base excretion; however, CO2 exposure resulted in a dose dependent increase in acid excretion during the initial 2 h. This returned to baseline levels during the second 2 h interval for exposures up to 5,000 μatm, but remained elevated for exposures above 15,000 μatm. Plasticity was assessed via gene expression in three CO2 treatments: environmentally realistic 1,000 and 6,000 μatm exposures, and a proof-of-principle 30,000 μatm exposure. Few differences were observed at 1,000 or 6,000 μatm however, 30,000 μatm stimulated widespread up-regulation. Translocation of V-type ATPase after 1 h of exposure to 30,000 μatm was also assessed; however, no evidence of translocation was found. These results indicate that red drum can quickly compensate to environmentally relevant acid-base disturbances using baseline cellular machinery, yet are capable of plasticity in response to extreme acid-base challenges.

  2. Not All Bones are Created Equal - Using Zebrafish and Other Teleost Species in Osteogenesis Research

    NARCIS (Netherlands)

    Apschner, A.; Schulte-Merker, S.; Witten, P.E.

    2011-01-01

    Developmental osteogenesis and pathologies of mineralized tissues are areas of intense investigations in the mammalian field, but different from other areas of organ formation and developmental biology, zebrafish have been somewhat slow in joining the area of bone research. In recent years, however,

  3. A method for mass harvesting islets (Brockmann bodies) from teleost fish.

    Science.gov (United States)

    Yang, H; Wright, J R

    1995-01-01

    In certain species of fish, the insulin-producing tissue is uniquely located in separate structures called Brockmann bodies (BBs). Tilapia BBs have been shown to be a simple and inexpensive source of islet cells for xenotransplantation research. Each donor tilapia contains roughly 12-15 BBs, measuring from 0.3 to 5.0 mm in maximum dimension, in a triangular region of adipose tissue bounded by the liver, stomach, and spleen/gallbladder. At present, the larger BBs (usually 2-4) are harvested by microdissecting these "BB regions" using jeweler's forceps and microvascular scissors while being visualized with the aid of a dissecting microscope. It is a simple but time-consuming task that would not be applicable for harvesting massive amounts of BB tissue for large animal studies. Therefore, we have developed an easier and more efficient method of harvesting BBs based on a standard enzymatic method for isolating human adipocytes. BB regions are harvested from donor fish and pooled into a 50 mL plastic tube containing collagenase Type II (3 mg/mL) in Hank's balanced salt solution (HBSS); the tube is then placed in a 37 degrees C waterbath/shaker for roughly 15 min. The exact length of the digestion interval is determined by visual inspection of the tube to determine whether the BBs have been liberated. The digestion is then stopped by adding excess cold HBSS. The adipocytes float while the BBs and residual connective tissue (i.e., a few blood vessels, nerves, and bile ducts) form a pellet. The pellet is washed several times in HBSS and then placed in a culture dish. The BBs are easily handpicked with a siliconized pipette. Based on functional data and DNA content, this new method roughly doubles or triples our yield of BB tissue per donor fish. To determine whether BBs harvested in this manner functioned in a manner similar to those harvested by microdissection, we performed a series of transplants using mass-harvested BBs. Long-term normoglycemia was achieved in streptozotocin-diabetic nude mice and mean graft survival time was not altered in streptozotocin-diabetic euthymic balb/c mice. However, the total weight of donor fish required per recipient was decreased by 50% in both strains.

  4. Stomach contents of some shore-caught teleosts of Natal, South Mrica

    African Journals Online (AJOL)

    1985-09-25

    Sep 25, 1985 ... Natal nearshore substratum were visually analysed for percentage composition. Commonly caught fish, namely. Rhabdosargus sarba, R. holubi, Pomadasys commersonni,. Trachinotus african us and T. bot/a, were opportunistic omnivorous predators and fed largely on sand mussels and benthic crustacea.

  5. Stomach contents of some shore-caught teleosts of Natal, South Mrica

    African Journals Online (AJOL)

    Commonly caught fish, namely Rhabdosargus sarta, R. holubi, Pomadasys commersonni, Trachinotus africanus and T. botla, were opportunistic omnivorous predators and fed largely on sand mussels and benthic crustacea. Less frequently caught predatory fish (15 species) fed mainly on benthic crustacea and other ...

  6. LOCALIZATION OF Na+, K+-ATPASE AND OTHER ENZYMES IN TELEOST PSEUDOBRANCH

    Science.gov (United States)

    Dendy, Leslie A.; Deter, Russell L.; Philpott, Charles W.

    1973-01-01

    In an effort to determine the subcellular localization of sodium- and potassium-activated adenosine triphosphatase (Na+, K+-ATPase) in the pseudobranch of the pinfish Lagodon rhomboides, this tissue was fractionated by differential centrifugation and the activities of several marker enzymes in the fractions were measured. Cytochrome c oxidase was found primarily in the mitochondrial-light mitochondrial (M+L) fraction. Phosphoglucomutase appeared almost exclusively in the soluble (S) fraction. Monoamine oxidase was concentrated in the nuclear (N) fraction, with a significant amount also in the microsomal (P) fraction but little in M+L or S. Na+, K+-ATPase and ouabain insensitive Mg2+-ATPase were distributed in N, M+L, and P, the former having its highest specific activity in P and the latter in M+L. Rate sedimentation analysis of the M+L fraction indicated that cytochrome c oxidase and Mg2+-ATPase were associated with a rapidly sedimenting particle population (presumably mitochondria), while Na+, K+-ATPase was found primarily in a slowly sedimenting component. At least 75% of the Na+, K+-ATPase in M+L appeared to be associated with structures containing no Mg2+-ATPase. Kinetic properties of the two ATPases were studied in the P fraction and were typical of these enzymes in other tissues. Na+, K+-ATPase activity was highly dependent on the ratio of Na+ and K+ concentrations but independent of absolute concentrations over at least a fourfold range. PMID:4349221

  7. Relationships between otolith size and fish length in some mesopelagic teleosts (Myctophidae, Paralepididae, Phosichthyidae and Stomiidae).

    Science.gov (United States)

    Battaglia, P; Malara, D; Ammendolia, G; Romeo, T; Andaloro, F

    2015-09-01

    Length-mass relationships and linear regressions are given for otolith size (length and height) and standard length (LS ) of certain mesopelagic fishes (Myctophidae, Paralepididae, Phosichthyidae and Stomiidae) living in the central Mediterranean Sea. The length-mass relationship showed isometric growth in six species, whereas linear regressions of LS and otolith size fit the data well for all species. These equations represent a useful tool for dietary studies on Mediterranean marine predators. © 2015 The Fisheries Society of the British Isles.

  8. Conserved structure and expression of hsp70 paralogs in teleost fishes

    DEFF Research Database (Denmark)

    Metzger, David C.H.; Hansen, Jakob Hemmer; Schulte, Patricia M.

    2016-01-01

    present in the F. heteroclitus genome. Comparison of expression patterns in F. heteroclitus and Gasterosteus aculeatus demonstrates that hsp70-2 has a higher fold increase than hsp70-1 following heat shock in gill but not in muscle tissue, revealing a conserved difference in expression patterns between...

  9. Tissue distributions of fluoride and its toxicity in the gills of a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Cao, Jinling; Chen, Jianjie; Wang, Jundong; Wu, Xiangtian; Li, Yundong; Xie, Lingtian

    2013-04-15

    Fish take up fluoride directly from water and are susceptible to fluoride contamination of their environment. In this study, we examined the tissue distributions of fluoride and its toxicity in the gills of the common carp (Cyprinus carpio) chronically exposed to fluoride. Carp were exposed to a range of aqueous fluoride (35-124 mg/L) and sampled at 30, 60 and 90 days. The accumulation of fluoride in the tissues increased with the level and duration of exposure. Steady state was not achieved under the experimental conditions. The gills accumulated the highest levels of fluoride followed by the liver>brain>kidney>muscle>intestine. A dose-dependent inhibition was observed for the enzyme activities of Na(+)-K(+)-ATPase and Ca(2+)-ATPase in the gills after the fish were exposed for 90 days. Also, accumulation of fluoride was associated with the inhibition of superoxide dismutase (SOD) activities and a dose-dependent stimulation of malondialdehyde (MDA) levels in the gill tissues, suggesting that fluoride promoted oxidative stress in the fish. Microscopic examinations revealed injuries to gill tissues and chloride cells, with the severity of injury increasing with exposure concentration. These results suggest that chronic exposure to elevated concentrations of fluoride may induce toxicity in the common carp. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Evidence of lactate dehydrogenase-B allozyme effects in the teleost, Fundulus heteroclitus.

    Science.gov (United States)

    DiMichele, L; Paynter, K T; Powers, D A

    1991-08-23

    The evolutionary significance of protein polymorphisms has long been debated. Exponents of the balanced theory advocate that selection operates to maintain polymorphisms, whereas the neoclassical school argues that most genetic variation is neutral. Some studies have suggested that protein polymorphisms are not neutral, but their significance has been questioned because one cannot eliminate the possibility that linked loci were responsible for the observed differences. Evidence is presented that an enzymatic phenotype can affect carbon flow through a metabolic pathway. Glucose flux differences between lactate dehydrogenase-B phenotypes of Fundulus heteroclitus were reversed by substituting the Ldh-B gene product of one homozygous genotype with that of another.

  11. The African catfish, Clarias gariepinus, a model for the study of reproductive endocrinology in teleosts

    NARCIS (Netherlands)

    Oordt, P.G.W.J. van; Goos, H.J.Th.

    1987-01-01

    In their natural habitat African catfish, Clarias gariepinus, show a discontinuous reproductive cycle. This cycle follows changes in the gonadotropic activity of the pituitary. Gonadotropin release has been shown to be under dual hypothalamic control, i.e. a gonadotropin-releasing hormone (GnRH) and

  12. X-ray-induced dicentric yields in lymphocytes of the teleost, Umbra limi

    Energy Technology Data Exchange (ETDEWEB)

    Suyama, I. (National Inst. of Radiological Sciences, Chiba (Japan). Div. of Environmental Health); Etoh, H. (National Inst. of Radiological Sciences, Chiba (Japan). Div. of Biology)

    1983-01-01

    A microculture technique was applied to the study of lymphocytes of Umbra limi, which have a low number of large meta- and submetacentric chromosomes (2n=22). On the 5th day (90 h) and later after initiation of culture at 20/sup 0/C, some cultures provided well spread metaphase chromosomes for analyses. After initiation, cultures were irradiated with 50, 100, 150 and 200 R of 200 kVp X-rays. The cultures were harvested on the 5th day, at which time all arrested metaphase chromosomes were in their first division. The dicentric yields induced in X-irradiated Umbra lymphocytes were observed to be significantly (P=0.05) lower than those in human lymphocytes. The resulting dose-response relationship for dicentric yield was described by the quadratic equation Y=aD+bD/sup 2/. The advantage of this method lies in the fact that small amounts (0.1 ml) of blood can be repeatedly withdrawn from the fish after a minimal interval of 2 weeks.

  13. X-ray-induced dicentric yields in lymphocytes of the teleost, Umbra limi

    International Nuclear Information System (INIS)

    Suyama, I.; Etoh, H.

    1983-01-01

    A microculture technique was applied to the study of lymphocytes of Umbra limi, which have a low number of large meta- and submetacentric chromosomes (2n=22). On the 5th day (90 h) and later after initiation of culture at 20 0 C, some cultures provided well spread metaphase chromosomes for analyses. After initiation, cultures were irradiated with 50, 100, 150 and 200 R of 200 kVp X-rays. The cultures were harvested on the 5th day, at which time all arrested metaphase chromosomes were in their first division. The dicentric yields induced in X-irradiated Umbra lymphocytes were observed to be significantly (P=0.05) lower than those in human lymphocytes. The resulting dose-response relationship for dicentric yield was described by the quadratic equation Y=aD+bD 2 . The advantage of this method lies in the fact that small amounts (0.1 ml) of blood can be repeatedly withdrawn from the fish after a minimal interval of 2 weeks. (orig./AJ)

  14. Embryonic suckling and maternal specializations in the live-bearing teleost Zoarces viviparus

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Steffensen, John Fleng; Sørensen, Thomas Flarup

    2010-01-01

    , morphological and behavioural adaptations, which we propose as the responsible mechanisms for the exchange of nutrients and gases between the maternal organism and her embryos. Ovarian follicles contain an internal glomerulus-like structure within the distal tip of each follicle. Ultrastructural examination...... indicated a capacity for steroid synthesis and secretion. Gel electrophoresis demonstrated a protein size distribution in the follicular fluid different from that of the maternal serum, and that ovarian fluid is devoid of protein. From vascular casts and histological sections the follicle was reconstructed....... The glomerulus has a central canal that is exteriorized at the tip of the follicle, allowing passage of follicular fluid. Oxygen measurements across the ovary of near-term females showed a strongly hypoxic ovary lumen, yet ovarian fluid adjacent to follicles was oxygen saturated. As another novel observation...

  15. Band 3 protein function in teleost fish erythrocytes: effect of oxygenation-deoxygenation

    Czech Academy of Sciences Publication Activity Database

    Russo, A.; Tellone, E.; Ficarra, S.; Giardina, B.; Bellocco, E.; Lagana, G.; Leuzzi, U.; Kotyk, Arnošt; Galtieri, A.

    2008-01-01

    Roč. 57, č. 1 (2008), s. 49-54 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z50110509 Keywords : erythrocytes * hemoglobin * band 3 protein Subject RIV: CE - Biochemistry Impact factor: 1.653, year: 2008

  16. Testicular structure in three viviparous species of teleosts in the genus Jenynsia (Anablepidae).

    Science.gov (United States)

    Martínez, V H; Monasterio de Gonzo, G; Uribe, M C; Grier, H J

    2014-01-01

    Histological structure of the testes and development of spermatozoa in Jenynsia species is described using light, scanning and transmission electron microscopy. The testis type is restricted spermatogonial, wherein spermatogonia are restricted to the distal ends of lobules, typical of the Atherinomorpha, and spermatogenesis is continuous throughout the year in wild-caught fish. Within the testicular lobes there are lobular germinal compartments wherein the functional units are spermatocysts, whose borders are formed by Sertoli cells. Spermatocysts may contain meiotic primary spermatocytes, secondary spermatocytes, spermatids, undergoing spermiogenesis, or spermatozoa. Spermatocysts with later stages of developing sperm are located proximal to the testicular ducts. During spermiogenesis, spermatid nuclei become elongated. As this occurs, the nucleus develops a deep, central fossa that contains the centriolar complex. As the flagellum grows, enlarging spermatid mitochondria migrate posteriorly alongside the flagellum but remain separated from it by the cytoplasmatic canal, an indentation of the plasma membrane. Between the enlarged mitochondria and plasma membrane, a sub-mitochondrial net develops. In longitudinal sections, the enlarged mitochondria are stacked in a zig-zag fashion, and in transverse sections they appear as a ring surrounding the flagellum, but separated from it by the cytoplasmic canal. Spermatozoa of the 3 jenynsiid species have an introsperm complex composed of a long mid-piece whose flagellum has a single "wing." Within the efferent ducts and the tubular gonopodium, sperm are lightly packed in a side by side fashion which facilitates their transfer into the female reproductive tract. This study presents detailed descriptions of testicular organization and cytological characterization of the stages of spermatozoa differentiation in 3 species of Jenynsia from northwestern Argentina ( J. alternimaculata , J. multidentata and J. maculata ), in order to contribute to the understanding of testicular structure and development of spermatozoa in the context of evolution of viviparity in this fish lineage.

  17. Comparative histology in the liver and spleen of three species of freshwater teleost

    Directory of Open Access Journals (Sweden)

    Camila F. Sales

    2017-03-01

    Full Text Available ABSTRACT We describe and compare the histology of liver and spleen ofGeophagus brasiliensis (Perciformes, Hypostomus francisci (Siluriformes and Hoplias aff. malabaricus (Characiformes, tropical freshwater fishes. InG. brasiliensisandH. aff. malabaricusthe hepatocytes were arranged in tubular form whereas in H. franciscithey cord-like. In all species, hepatocytes presented glycogen, but in G. brasiliensis and H. aff. malabaricus they showed strong stained for hemossiderin in the cytoplasm. InG. brasiliensis and H. aff. malabaricus, melanomacrophage centres (MMCs were associated to hepatic structures and only in G. brasiliensis was observed intrahepatic exocrine pancreas. The spleen, in all species, was characterized by red and white pulp without boundary between the two regions, but only in H. francisci was recorded nodular organization in splenic parenchyma. The G. brasiliensisandH. aff. malabaricuspresented in the white pulp MMCs linked mainly to ellipsoids. Besides, we observed large MMCs in the spleen in relation to liver of G. brasiliensis and H. aff. malabaricus. In liver, highest values of reticular fibers and collagen were observed inG. brasiliensis. In spleen, highest values of reticular fibers and collagen were recorded inH. aff. malabaricusandH. francisci, respectively. Histological differences confirm the hypothesis that the phylogenetic distance is reflected in liver and spleen.

  18. Gill rakers in six teleost species: influence of feeding habit and body size

    Directory of Open Access Journals (Sweden)

    Ana Paula Gottlieb Almeida

    2013-12-01

    Full Text Available This study analyzed the structure of the gill rakers of Parapimelodus valenciennis and Parapimelodus nigribarbis (planktivorous, Serrasalmus maculatus and Hoplias malabaricus (piscivorous, Iheringichthys labrosus (benthophagous and Hypostomus commersonii (detritivorous and related it with the body size and feeding habits of these species. The species of Parapimelodus and H. commersonii showed long, filiform and closely spaced gill rakers, similar to those of species that use the gill rakers as a filter to assist in the retention of small particles. The widely spaced gill rakers of I. labrosus probably allow the retention of insect larvae, but not particles of inorganic matter. In H. malabaricus and S. maculatus the gill rakers are most likely related to prey capture and swallowing, as observed in other piscivorous species. In general, gill raker length and the distance between gill rakers have a positive relationship with fish length. The gill rakers show adaptations related to the diet of the fish, but morphological variation may occur even between species whose feeding habits are the same.

  19. Nitrogen metabolism of the intestine during digestion in a teleost fish, the plainfin midshipman (Porichthys notatus).

    Science.gov (United States)

    Bucking, Carol; LeMoine, Christophe M R; Craig, Paul M; Walsh, Patrick J

    2013-08-01

    Digestion affects nitrogen metabolism in fish, as both exogenous and endogenous proteins and amino acids are catabolized, liberating ammonia in the process. Here we present a model of local detoxification of ammonia by the intestinal tissue of the plainfin midshipman (Porichthys notatus) during digestion, resulting in an increase in urea excretion of gastrointestinal origin. Corroborating evidence indicated whole-animal ammonia and urea excretion increased following feeding, and ammonia levels within the lumen of the midshipman intestine increased to high levels (1.8±0.4 μmol N g(-1)). We propose that this ammonia entered the enterocytes and was detoxified to urea via the ornithine-urea cycle (O-UC) enzymes, as evidenced by a 1.5- to 2.9-fold post-prandial increase in glutamine synthetase activity (0.14±0.05 and 0.28±0.02 μmol min(-1) g(-1) versus 0.41±0.03 μmol min(-1) g(-1)) and an 8.7-fold increase in carbamoyl phosphate synthetase III activity (0.3±1.2 versus 2.6±0.4 nmol min(-1) g(-1)). Furthermore, digestion increased urea production by isolated gastrointestinal tissue 1.7-fold, supporting our hypothesis that intestinal tissue synthesizes urea in response to feeding. We further propose that the intestinal urea may have been excreted into the intestinal lumen via an apical urea transporter as visualized using immunohistochemistry. A portion of the urea was then excreted to the environment along with the feces, resulting in the observed increase in urea excretion, while another portion may have been used by intestinal ureolytic bacteria. Overall, we propose that P. notatus produces urea within the enterocytes via a functional O-UC, which is then excreted into the intestinal lumen. Our model of intestinal nitrogen metabolism does not appear to be universal as we were unab le to activate the O-UC in the intestine of fed rainbow trout. However, literature values suggest that multiple fish species could follow this model.

  20. Functional and structural characterization of a eurytolerant calsequestrin from the intertidal teleost Fundulus heteroclitus.

    Directory of Open Access Journals (Sweden)

    A Carl Whittington

    Full Text Available Calsequestrins (CSQ are high capacity, medium affinity, calcium-binding proteins present in the sarcoplasmic reticulum (SR of cardiac and skeletal muscles. CSQ sequesters Ca²⁺ during muscle relaxation and increases the Ca²⁺-storage capacity of the SR. Mammalian CSQ has been well studied as a model of human disease, but little is known about the environmental adaptation of CSQ isoforms from poikilothermic organisms. The mummichog, Fundulus heteroclitus, is an intertidal fish that experiences significant daily and seasonal environmental fluctuations and is an interesting study system for investigations of adaptation at the protein level. We determined the full-length coding sequence of a CSQ isoform from skeletal muscle of F. heteroclitus (FCSQ and characterized the function and structure of this CSQ. The dissociation constant (K(d of FCSQ is relatively insensitive to changes in temperature and pH, thus indicating that FCSQ is a eurytolerant protein. We identified and characterized a highly conserved salt bridge network in FCSQ that stabilizes the formation of front-to-front dimers, a process critical to CSQ function. The functional profile of FCSQ correlates with the natural history of F. heteroclitus suggesting that the eurytolerant function of FCSQ may be adaptive.

  1. Teleost polarization vision: how it might work and what it might be good for

    NARCIS (Netherlands)

    Kamermans, Maarten; Hawryshyn, Craig

    2011-01-01

    In this review, we will discuss the recent literature on fish polarization vision and we will present a model on how the retina processes polarization signals. The model is based on a general retinal-processing scheme and will be compared with the available electrophysiological data on polarization

  2. Teleost polarization vision: how it might work and what it might be good for.

    Science.gov (United States)

    Kamermans, Maarten; Hawryshyn, Craig

    2011-03-12

    In this review, we will discuss the recent literature on fish polarization vision and we will present a model on how the retina processes polarization signals. The model is based on a general retinal-processing scheme and will be compared with the available electrophysiological data on polarization processing in the retina. The results of this model will help illustrate the functional significance of polarization vision for both feeding behaviour and navigation. First, we examine the linkage between structure and function in polarization vision in general.

  3. Respiratory Responses to Stimulation of Branchial Vagus Nerve Ganglia of a Teleost Fish

    NARCIS (Netherlands)

    Ballintijn, C.M.; Luiten, P.G.M.

    1983-01-01

    The effects of electrical stimulation of epibranchial vagus ganglia upon respiration of the carp were investigated. Single shocks evoked fast twitch responses in a number of respiratory muscles with latencies around 18 msec to the beginning and 30-35 msec to the peak of activity. Shocks given during

  4. Skin and scales of teleost fish: Simple structure but high performance and multiple functions

    Science.gov (United States)

    Vernerey, Franck J.; Barthelat, Francois

    2014-08-01

    Natural and man-made structural materials perform similar functions such as structural support or protection. Therefore they rely on the same types of properties: strength, robustness, lightweight. Nature can therefore provide a significant source of inspiration for new and alternative engineering designs. We report here some results regarding a very common, yet largely unknown, type of biological material: fish skin. Within a thin, flexible and lightweight layer, fish skins display a variety of strain stiffening and stabilizing mechanisms which promote multiple functions such as protection, robustness and swimming efficiency. We particularly discuss four important features pertaining to scaled skins: (a) a strongly elastic tensile behavior that is independent from the presence of rigid scales, (b) a compressive response that prevents buckling and wrinkling instabilities, which are usually predominant for thin membranes, (c) a bending response that displays nonlinear stiffening mechanisms arising from geometric constraints between neighboring scales and (d) a robust structure that preserves the above characteristics upon the loss or damage of structural elements. These important properties make fish skin an attractive model for the development of very thin and flexible armors and protective layers, especially when combined with the high penetration resistance of individual scales. Scaled structures inspired by fish skin could find applications in ultra-light and flexible armor systems, flexible electronics or the design of smart and adaptive morphing structures for aerospace vehicles.

  5. Are coping styles consistent in the teleost fish Sparus aurata through sexual maturation and sex reversal?

    Science.gov (United States)

    Castanheira, Maria Filipa; Martínez Páramo, Sonia; Figueiredo, F; Cerqueira, Marco; Millot, Sandie; Oliveira, Catarina C V; Martins, Catarina I M; Conceição, Luís E C

    2016-10-01

    Individual differences in behaviour and physiological responses to stress are associated with evolutionary adaptive variation and thus raw material for evolution. In farmed animals, the interest in consistent trait associations, i.e. coping styles, has increased dramatically over the last years. However, one of limitations of the available knowledge, regarding the temporal consistency, is that it refers always to short-term consistency (usually few weeks). The present study used an escape response during a net restraining test, previously shown to be an indicative of coping styles in seabream, to investigate long-term consistency of coping styles both over time and during different life history stages. Results showed both short-term (14 days) consistency and long-term (8 months) consistency of escape response. However, we did not found consistency in the same behaviour after sexual maturation when the restraining test was repeated 16, 22 and 23 months after the first test was performed. In conclusion, this study showed consistent behaviour traits in seabream when juveniles, and a loss of this behavioural traits when adults. Therefore, these results underline that adding a life story approach to data interpretation as an essential step forward towards coping styles foreground. Furthermore, a fine-tuning of aquaculture rearing strategies to adapt to different coping strategies may need to be adjusted differently at early stages of development and adults to improve the welfare of farmed fish.

  6. Neuroanatomical Evidence for Catecholamines as Modulators of Audition and Acoustic Behavior in a Vocal Teleost.

    Science.gov (United States)

    Forlano, Paul M; Sisneros, Joseph A

    2016-01-01

    The plainfin midshipman fish (Porichthys notatus) is a well-studied model to understand the neural and endocrine mechanisms underlying vocal-acoustic communication across vertebrates. It is well established that steroid hormones such as estrogen drive seasonal peripheral auditory plasticity in female Porichthys in order to better encode the male's advertisement call. However, little is known of the neural substrates that underlie the motivation and coordinated behavioral response to auditory social signals. Catecholamines, which include dopamine and noradrenaline, are good candidates for this function, as they are thought to modulate the salience of and reinforce appropriate behavior to socially relevant stimuli. This chapter summarizes our recent studies which aimed to characterize catecholamine innervation in the central and peripheral auditory system of Porichthys as well as test the hypotheses that innervation of the auditory system is seasonally plastic and catecholaminergic neurons are activated in response to conspecific vocalizations. Of particular significance is the discovery of direct dopaminergic innervation of the saccule, the main hearing end organ, by neurons in the diencephalon, which also robustly innervate the cholinergic auditory efferent nucleus in the hindbrain. Seasonal changes in dopamine innervation in both these areas appear dependent on reproductive state in females and may ultimately function to modulate the sensitivity of the peripheral auditory system as an adaptation to the seasonally changing soundscape. Diencephalic dopaminergic neurons are indeed active in response to exposure to midshipman vocalizations and are in a perfect position to integrate the detection and appropriate motor response to conspecific acoustic signals for successful reproduction.

  7. Whole-body calcium flux rates in cichlid teleost fish Oreochromis mossambicus adapted to freshwater

    International Nuclear Information System (INIS)

    Flik, G.; Fenwick, J.C.; Kolar, Z.; Mayer-Gostan, N.; Wendelaar Bonga, S.E.

    1985-01-01

    Radiotracer techniques were used to measure influx and efflux rates of Ca 2+ in freshwater-adapted Oreochromis mossambicus. The influx rate of Ca 2+ is related to body weight (W) as Fin = 50W0.805 nmol Ca 2+ /h. For a 20-g fish the calculated influx rate was 558 nmol Ca 2+ /h, and this was attributed largely to extraintestinal uptake since the drinking rate was estimated to be only 28 microliter water/h, which corresponds to an intake of 22.4 nmol Ca 2+ /h. The Ca 2+ efflux rate was calculated using the initial rate of appearance of radiotracer in the ambient water and the specific activity of plasma Ca 2+ . Tracer efflux rates were constant over 6-8 h, which indicated that there was no substantial loss of tracer in either the urine or the feces because this would have resulted in random bursts of tracer loss. Efflux rates then primarily represent integumentary and presumably branchial efflux rates. The efflux rate of Ca 2+ is related to body weight as Fout = 30W0.563 nmol Ca 2+ /h, which means an efflux rate of 162 nmol Ca 2+ /h for a 20-g fish. The net whole-body Ca 2+ influx, calculated as Fnet = Fin - Fout, was 396 nmol/h for a 20-g fish, which proves that the ambient water is an important source of Ca 2+

  8. Purifying selection on leptin genes in teleosts may be due to ...

    Indian Academy of Sciences (India)

    2014-08-27

    Aug 27, 2014 ... research into the properties and physiological action of lep- tin. In initial ... functions of leptin were its influence on metabolic rate and mobilization ..... Minokoshi Y. and Kahn B. B. 2003 Role of AMP-activated protein kinase in ...

  9. Identification of a novel IL-1 cytokine family member in teleost fish.

    Science.gov (United States)

    Wang, Tiehui; Bird, Steve; Koussounadis, Antonis; Holland, Jason W; Carrington, Allison; Zou, Jun; Secombes, Christopher J

    2009-07-15

    A novel IL-1 family member (nIL-1F) has been discovered in fish, adding a further member to this cytokine family. The unique gene organization of nIL-1F, together with its location in the genome and low homology to known family members, suggests that this molecule is not homologous to known IL-1F. Nevertheless, it contains a predicted C-terminal beta-trefoil structure, an IL-1F signature region within the final exon, a potential IL-1 converting enzyme cut site, and its expression level is clearly increased following infection, or stimulation of macrophages with LPS or IL-1beta. A thrombin cut site is also present and may have functional relevance. The C-terminal recombinant protein antagonized the effects of rainbow trout rIL-1beta on inflammatory gene expression in a trout macrophage cell line, suggesting it is an IL-1beta antagonist. Modeling studies confirmed that nIL-1F has the potential to bind to the trout IL-1RI receptor protein, and may be a novel IL-1 receptor antagonist.

  10. Stress and parental care in a wild Teleost fish: insights from exogenous supraphysiological cortisol implants.

    Science.gov (United States)

    O'Connor, Constance M; Gilmour, Kathleen M; Arlinghaus, Robert; Van Der Kraak, Glen; Cooke, Steven J

    2009-01-01

    Male largemouth bass (Micropterus salmoides) provide sole parental care over a 4-6-wk period to a single brood, fanning the eggs to keep them oxygenated and free of silt and defending the brood until the offspring develop antipredator tactics. During this period, fish are highly active and have few opportunities for feeding, so this activity is energetically costly. To understand some of the consequences of stress during this challenging period, we injected fish with cortisol suspended in coconut oil to experimentally raise circulating cortisol in parental males for the first week of the parental care period. We compared parental care behavior between cortisol-treated, sham-treated (injected only with coconut oil), and control parental males. We further compared physiological parameters associated with metabolism and reproductive function between cortisol-treated and control males. The cortisol injections resulted in supraphysiological levels of circulating plasma cortisol, giving us insight into potential maximal effects of stress during parental care. At these supraphysiological levels, the cortisol-treated fish displayed higher concentrations of circulating glucose and cholesterol and lower concentrations of circulating triglycerides when compared with control fish, with no change in plasma concentrations of total protein. Plasma concentrations of androgen were similarly unaffected by cortisol treatment. In the short term (initial 1-2 wk), parental care of eggs and egg-sac fry was maintained by all groups, with no differences observed in behavior (e.g., tending, vigilance, defense) among the groups. However, the cortisol-treated fish abandoned their offspring at a higher rate than in the control or sham groups. The fish treated with cortisol also tended to develop external Saprolegnian infections, indicative of compromised immune function. These data demonstrate that exogenous cortisol elevation during parental care results in changes in energy use and a decrease in immune function. Interestingly, the data also suggest resistance to stress during parental care in largemouth bass, with no changes in parental care behavior before abandonment.

  11. Isolation of a novel aquaglyceroporin from a marine teleost (Sparus auratus): function and tissue distribution.

    NARCIS (Netherlands)

    Santos, C.R.; Estevao, M.D.; Fuentes, J.; Cardoso, -; Fabra, M.; Passos, A.L.; Detmers, F.J.M.; Deen, P.M.T.; Cerda, J.; Power, D.M.

    2004-01-01

    The aquaporins (formerly called the major intrinsic protein family) are transmembrane channel proteins. The family includes the CHIP group, which are functionally characterised as water channels and the GLP group, which are specialised for glycerol transport. The present study reports the

  12. Tumor necrosis factor alpha of teleosts: in silico characterization and homology modeling

    Directory of Open Access Journals (Sweden)

    Tran Ngoc Tuan

    2016-10-01

    Full Text Available Tumor necrosis factor alpha (TNF- is known to be crucial in many biological activities of organisms. In this study, physicochemical properties and modeling of TNF- protein of fish was analyzed using in silico approach. TNF- proteins selected from fish species, including grass carp (Ctenopharyngodon idella, zebra fish (Danio rerio, Nile tilapia (Oreochromis niloticus, goldfish (Carassius auratus, and rainbow trout (Oncorhynchus mykiss were used in this study. Physicochemical characteristics with molecular weight, theoretical isoelectric point, extinction coefficient, aliphatic index, instability index, total number of negatively charged residues and positively charged residues, and grand average of hydropathicity were computed. All proteins were classified as transmembrane proteins. The “transmembrane region” and “TNF” domain were identified from protein sequences. The function prediction of proteins was also performed. Alpha helices and random coils were dominating in the secondary structure of the proteins. Three-dimensional structures were predicted and verified as good structures for the investigation of TNF- of fish by online server validation.

  13. Altered steroid metabolism in several teleost species exposed to endocrine disrupting substances in refuse dump leachate

    NARCIS (Netherlands)

    Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Balk, L.

    2003-01-01

    Endocrine disruption associated with reproductive failure has been reported previously in female perch (Perca fluviatilis) and roach (Rutilus rutilus) from Lake Molnbyggen in Sweden and in female brook trout (Salvelinus fontinalis) from Vadbäcken, a stream emptying into Molnbyggen. Both Molnbyggen

  14. Stress and food deprivation: linking physiological state to migration success in a teleost fish.

    Science.gov (United States)

    Midwood, Jonathan D; Larsen, Martin H; Aarestrup, Kim; Cooke, Steven J

    2016-12-01

    Food deprivation is a naturally occurring stressor that is thought to influence the ultimate life-history strategy of individuals. Little is known about how food deprivation interacts with other stressors to influence migration success. European populations of brown trout (Salmo trutta) exhibit partial migration, whereby a portion of the population smoltifies and migrates to the ocean, and the rest remain in their natal stream. This distinct, natural dichotomy of life-history strategies provides an excellent opportunity to explore the roles of energetic state (as affected by food deprivation) and activation of the glucocorticoid stress response in determining life-history strategy and survival of a migratory species. Using an experimental approach, the relative influences of short-term food deprivation and experimental cortisol elevation (i.e. intra-coelomic injection of cortisol suspended in cocoa butter) on migratory status, survival and growth of juvenile brown trout relative to a control were evaluated. Fewer fish migrated in both the food deprivation and cortisol treatments; however, migration of fish in cortisol and control treatments occurred at the same time while that of fish in the food deprivation treatment was delayed for approximately 1 week. A significantly greater proportion of trout in the food deprivation treatment remained in their natal stream, but unlike the cortisol treatment, there were no long-term negative effects of food deprivation on growth, relative to the control. Overall survival rates were comparable between the food deprivation and control treatments, but significantly lower for fish in the cortisol treatment. Food availability and individual energetic state appear to dictate the future life-history strategy (migrate or remain resident) of juvenile salmonids while experimental elevation of the stress hormone cortisol causes impaired growth and reduced survival of both resident and migratory individuals. © 2016. Published by The Company of Biologists Ltd.

  15. Gastrointestinal uptake of cadmium and zinc by a marine teleost Acanthopagrus schlegeli

    International Nuclear Information System (INIS)

    Zhang Li; Wang Wenxiong

    2007-01-01

    Gastrointestinal metal uptake represents a potential route for metal bioaccumulation in marine fish. Drinking of seawater for osmoregulation causes constant waterborne exposure of the gastrointestinal tract. Tissue specific Cd and Zn accumulation and distribution were investigated in juvenile black sea bream (Acanthopagrus schlegeli) exposed to waterborne Cd (5.7 nM) and Zn (2.6 nM) for 4 h-7 days. The intestine accumulated a large portion of the Cd (43-58%) and Zn (18-28%), and had the highest Cd (>1.0 nmol g -1 ) and Zn (>1.8 nmol g -1 ) concentrations of all body fractions, suggesting that the intestines were the major uptake sites for these waterborne metals. Among all the segments of the gastrointestinal tract, the anterior intestine played the most important role in Cd and Zn uptake. A gastrointestinal injection assay was conducted to distinguish waterborne metal uptake by the intestines and the gills. The intestine contained over 90% of the Cd in the body after depuration for 3-7 days, suggesting that little waterborne Cd entered the rest of the body through the intestine, and that Cd may exert its toxic effects on the gastrointestinal system. In contrast, intestine retained less than 20% of the total Zn after depuration, suggesting that Zn tended to be transported from the intestine to the internal tissues via the cardiovascular system. The uptake kinetics of waterborne Cd and Zn by the intestines and the gills were determined as a first-order and saturated pattern, respectively, over a wide range of ambient metal concentrations (6.2 nM-4.5 μM for Cd, and 13 nM-15 μM for Zn). An in vitro intestinal perfusion assay investigated the effects of intestinal metal composition and drinking rate on uptake. The presence of EDTA significantly reduced intestinal Zn uptake to 11%, while cysteine improved it by 59%. The intestinal Cd and Zn uptake rates were unaffected by the perfusion rate

  16. Stress and food deprivation: linking physiological state to migration success in a teleost fish

    DEFF Research Database (Denmark)

    Midwood, J.D.; Larsen, Martin Hage; Aarestrup, Kim

    2016-01-01

    for the cortisol treatment. Food availability and individual energetic state appear to dictate the future life-history strategy (migrate or remain resident) of juvenile salmonids while experimental elevation of the stress hormone cortisol caused impaired growth and reduced survival of both resident and migratory......Food deprivation (FD) is a naturally occurring stressor that is thought to influence the ultimate life-history strategy of individuals. Little is known about how FD interacts with other stressors to influence migration success. European populations of brown trout (Salmo trutta) exhibit partial...... of the glucocorticoid stress response in determining life-history strategy and survival of a migratory species. Using an experimental approach, the relative influences of short-term FD and experimental cortisol elevation (i.e., intra-coelomic injection of cortisol suspended in cocoa butter) on migratory status...

  17. X-ray microanalysis of Zn in the taste organ of the teleost Ameiurus nebulosus

    International Nuclear Information System (INIS)

    Reutter, K.

    1983-01-01

    The trace metal Zn seems to be essential for the normal functioning of the gustatory sense. It was tried to localize Zn within the peripheral and central parts of the bullhead's gustatory system by the use of scanning electron microscopy and X-ray microanalysis. In freeze dried preparations of the bullhead's barbel taste buds (and the taste buds of rabbits) Zn is found in randomly distributed granules, which cannot be related to distinct taste bud regions. Furthermore, Zn occurs in subunits of the central gustatory nuclei, the vagal and facial lobe of the rhombencephalon. Therefore Zn appears to be essential for intact peripheral as well as central gustatory processes, at least in lower vertebrates. (author)

  18. N-acetylcysteine manipulation fails to elicit an increase in glutathione in a teleost model

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Larsen, Martin Hage; Aarestrup, Kim

    2018-01-01

    and vegetable shortening, at two different concentrations (100 and 400 mg/kg), with the appropriate controls and shams, under controlled laboratory settings. We found that NAC failed to elicit an increase in GSH over three time periods and concluded that NAC is not an effective method to enhance GSH levels...

  19. Mucosal immunity and B cells in teleosts: effect of vaccination and stress.

    Directory of Open Access Journals (Sweden)

    David eParra

    2015-07-01

    Full Text Available Fish are subjected to several insults from the environment, which may endanger animal survival. Mucosal surfaces are the first line of defense against those threats and they act as a physical barrier to protect the animal but also function as immunologically active tissues. Thus, four mucosal-associated lymphoid tissues have been described in fish, which lead the immune responses in gut, skin, gills and nose. Humoral and cellular immunity, as well as its regulation and the factors that influence the response in these mucosal lymphoid tissues is still not well known in most of fish species. Mucosal B-lymphocytes and immunoglobulins (Igs are one of the key players in the immune response after vaccination. Recent findings about IgT in trout have delimited the compartmentalization of immune response in systemic and mucosal. The existence of IgT as a specialized mucosa Ig gives us the opportunity of measuring mucosal specific responses after vaccination, a fact that was not possible until recently in most of the fish species. Vaccination process is influenced by several factors, being stress one of the main stimuli determining the success of the vaccine. Thus, one of the major goals in a vaccination process is to avoid possible situations of stress, which might interfere with fish immune performance. However, the interaction between immune and neuroendocrine systems at mucosal tissues is still unknown. In this review we will summarized the latest findings about B-lymphocytes and immunoglobulins in mucosal immunity and the effect of stress and vaccines on B cell response at mucosal sites. It is important to point out that a small number of studies have been published regarding mucosal stress and very few about the influence of stress over mucosal B-lymphocytes.

  20. Libavaida sugrusida uherles ja vurles kehus* / Maria Ulfsak-Šeripova

    Index Scriptorium Estoniae

    Ulfsak-Šeripova, Maria, 1981-

    2010-01-01

    Tim Burtoni filmist "Alice Imedemaal" (USA 2010), stsenarist Linda Woolverton, peaosades Mia Wasikowska, Johnny Depp. Lisaks kaks arvamust "3D poolt", autor Mann Jõgeda ja "3D vastu", autor Margit Tõnson

  1. Tim Burton lavastab Batmani muusikali. Placido Domingo palkas "Star Warsi" võluri. MTV muusikaauhindade show'l narriti Michael Jacksonit. Hendrixi põlenud kitarr läheb müüki

    Index Scriptorium Estoniae

    2002-01-01

    Jim Steinman kirjutab muusikat Tim Burtoni 2005. aastal lavale tulevale Batmani muusikalile. Los Angelese ooperimaja juht Domingo palkas George Lucase Wagneri ooperi "Nibelungide sõrmus" eriefektide ettevalmistamiseks. Britney Spears nimetas Michael Jacksonit Millenniumi artistiks.

  2. Pharmacological characterization of the oxytocic peptides in the pituitary of a marine teleost fish (pollachius virens) (1961); Caracterisation pharmacologique des peptides ocytociques dans la glande pituitaire d'un poisson marin teleost (pollachius virens) (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Maetz, J; Morel, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Heller, H; Pickering, B T [Bristol Univ. (United Kingdom)

    1961-07-01

    Demonstration of the existence, in the neurohypophysis of a marine fish (pollachius virens), of an oxytocic-active peptide different to the oxytocin in mammals and to the arginine vasotocin. (authors) [French] Mise en evidence dans la neurohypophyse d'un poisson marin (pollachius virens) d'un peptide a activite ocytocique different de l'ocytocine des mammiferes et de l'arginine vasotocine. (auteurs)

  3. Pharmacological characterization of the oxytocic peptides in the pituitary of a marine teleost fish (pollachius virens) (1961); Caracterisation pharmacologique des peptides ocytociques dans la glande pituitaire d'un poisson marin teleost (pollachius virens) (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Maetz, J.; Morel, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Heller, H.; Pickering, B.T. [Bristol Univ. (United Kingdom)

    1961-07-01

    Demonstration of the existence, in the neurohypophysis of a marine fish (pollachius virens), of an oxytocic-active peptide different to the oxytocin in mammals and to the arginine vasotocin. (authors) [French] Mise en evidence dans la neurohypophyse d'un poisson marin (pollachius virens) d'un peptide a activite ocytocique different de l'ocytocine des mammiferes et de l'arginine vasotocine. (auteurs)

  4. Haematological characteristics of Brazilian Teleosts: III. Parameters of the hybrid tambacu (Piaractus mesopotamicus Holmberg x Colossoma macropomum Cuvier (Osteichthyes, Characidae

    Directory of Open Access Journals (Sweden)

    Marcos Tavares-Dias

    2000-12-01

    Full Text Available Fifty six specimens of the hybrid "tambacu" (Piaractus mesopotamicus Holmberg, 1887 male x Colossoma macropomum Cuvier, 1818 female were collected from fishfarm of Guariba, São Paulo, to evaluate their haematology. Fishes presented 400.0 to 3,100.0 g total weight and 20.0 to 52.0 cm total length. Haemoglobin, haematocrit, mean corpuscular haemoglobin content (MCHC and percentage of defense blood cells including leucocytes and thrombocytes, were studied. Statistical analysis showed positive correlation (P<0.01 between haematocrit, MCHC and haemoglobin rate. Nevertheless, thrombocytes and lymphocytes showed negative correlation (P<0.01.

  5. Pollutants and parasites in bycatch teleosts from south eastern Spanish Mediterranean's fisheries: Concerns relating the foodstuff harnessing

    International Nuclear Information System (INIS)

    Casadevall, Margarida; Torres, Jordi; El Aoussimi, Ahmed; Carbonell, Ana; Delgado, Eulàlia; Sarrà-Alarcón, Lídia; García-Ruíz, Cristina

    2016-01-01

    This research provides an evaluation of the quality and health status of some locally abundant fish species, usually otter-trawl bycatch species. The study was conducted in the southern and eastern Spanish Mediterranean coast. Mean concentration of heavy metals in muscle and parasitisation indices showed moderate levels. Higher lead concentration was found in fish from the western Alboran and arsenic, cadmium and mercury were more present on fishes from the eastern Alboran area, although most species analysed contain moderate levels of heavy metals in muscle. Concerning parasitisation, F. Anisakidae nematodes were present in all the species, except sardine. Only mercury showed a positive relationship with parasitisation. We also considered three feeding guilds. Metal mean concentrations were higher in benthivores and more littoral fishes. Pelagic planktivores species are the healthiest and the more suitable for consumers from the sanitary point of view. -- Highlights: •Planktophagous fishes always presented significant lower concentrations of heavy metals in muscle. •Benthivorous and fishes with mixed diets showed higher concentrations of heavy metals in muscle. •Fishes from the western Alboran and Vera Gulf areas presented higher levels of Pb. •Specimens infected (mainly by nematodes) had more concentration of mercury in muscle. •Overall, species and areas analysed in this work show moderate levels of parasite infection and heavy metals accumulation in muscle.

  6. Preliminary Study on the In vitro and In vivo Effects of Asparagopsis taxiformis Bioactive Phycoderivates on Teleosts

    Science.gov (United States)

    Marino, Fabio; Di Caro, Gianfranco; Gugliandolo, Concetta; Spanò, Antonio; Faggio, Caterina; Genovese, Giuseppa; Morabito, Marina; Russo, Annamaria; Barreca, Davide; Fazio, Francesco; Santulli, Andrea

    2016-01-01

    Several compounds from marine organisms have been studied for their potential use in aquaculture. Among the red algae, Asparagopsis taxiformis is considered one of the most promising species for the production of bioactive metabolites with numerous proposed applications. Here, the in vitro antibacterial activity, the easy handling and the absence of adverse effects on marine fish species are reported. Depending on the seasonal period of sampling, ethanol extracts of A. taxiformis exhibited significantly different inhibitory activity against fish pathogenic bacteria. The extract obtained in late spring showed strong antibacterial activity against Aeromonas salmonicida subsp. salmonicida, Vibrio alginolyticus, and V. vulnificus, and moderate activity against Photobacterium damselae subsp. damselae, P. damselae subsp. piscicida, V. harveyi and V. parahaemolyticus. Sea bass and gilthead sea bream were fed with pellets supplied with the alga and algal extracts. The absence of undesired effects on fish was demonstrated. Hematological and biochemical investigations allowed to confirm that the whole alga and its extracts could be proposed for a future application in aquaculture. PMID:27826246

  7. Preliminary Study on the in vitro and in vivo Effects of Asparagopsis taxiformis Bioactive Phycoderivates on Teleosts

    Directory of Open Access Journals (Sweden)

    Fabio Marino

    2016-10-01

    Full Text Available Several compounds from marine organisms have been studied for their potential use in aquaculture. Among the red algae, Asparagopsis taxiformis is considered one of the most promising species for the production of bioactive metabolites with numerous proposed applications. Here, the in vitro antibacterial activity, the easy handling and the absence of adverse effects on marine fish species are reported. Depending on the seasonal period of sampling, ethanol extracts of A. taxiformis exhibited significantly different inhibitory activity against fish pathogenic bacteria. The extract obtained in late spring showed strong antibacterial activity against Aeromonas salmonicida subsp. salmonicida, Vibrio alginolyticus, and V. vulnificus, and moderate activity against Photobacterium damselae subsp. damselae, P. damselae subsp. piscicida, V. harveyi and V. parahaemolyticus. Sea bass and gilthead sea bream were fed with pellets supplied with algae and algal extracts. The absence of undesired effects was demonstrated. Hematological and biochemical investigations allowed to confirm that the whole alga and its extracts could be proposed for a future application in aquaculture.

  8. Toxicological effects of irregularly shaped and spherical microplastics in a marine teleost, the sheepshead minnow (Cyprinodon variegatus).

    Science.gov (United States)

    Choi, Jin Soo; Jung, Youn-Joo; Hong, Nam-Hui; Hong, Sang Hee; Park, June-Woo

    2018-04-01

    The increasing global contamination of plastics in marine environments is raising public concerns about the potential hazards of microplastics to environmental and human health. Microplastics formed by the breakdown of larger plastics are typically irregular in shape. The objective of this study was to compare the effects of spherical or irregular shapes of microplastics on changes in organ distribution, swimming behaviors, gene expression, and enzyme activities in sheepshead minnow (Cyprinodon variegatus). Both types of microplastics accumulated in the digestive system, causing intestinal distention. However, when compared to spherical microplastics, irregular microplastics decreased swimming behavior (i.e., total distance travelled and maximum velocity) of sheepshead minnow. Both microplastics generated cellular reactive oxygen species (ROS), while ROS-related molecular changes (i.e., transcriptional and enzymatic characteristics) differed. This study provides toxicological insights into the impacts of environmentally relevant (fragmented) microplastics on fish and improves our understanding of the environmental effects of microplastics in the ecosystem. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Three nuclear and two membrane estrogen receptors in basal teleosts, Anguilla sp.: Identification, evolutionary history and differential expression regulation

    DEFF Research Database (Denmark)

    Lafont, Anne Gaëlle; Rousseau, Karine; Tomkiewicz, Jonna

    2016-01-01

    Estrogens interact with classical intracellular nuclear receptors (ESR), and with G-coupled membrane receptors (GPER). In the eel, we identified three nuclear (ESR1, ESR2a, ESR2b) and two membrane (GPERa, GPERb) estrogen receptors. Duplicated ESR2 and GPER were also retrieved in most extant teleo...

  10. Ultrastructural study of the effect of heavy metals on the regenerating tail fin of the teleost fish, Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    K.I. Atta

    2012-08-01

    In the tail fins of the specimens treated with Pb at 0.005 and 0.025 mg/l and Cd at 0.005 and 0.025 mg/l, at the seventh day postamputation, the lepidotrichia forming cells have dense patches of irregular lysosomes, swollen and degranulated rough endoplasmic reticulum, pyknotic mitochondria and vacuolated cytoplasm. In the tail fins of the specimens treated with Hg at 0.0006 mg/l, showed deformation of the lepidotrichia forming cells, there was an invasion of leucocytes and lysosomes. A progressive damage in the cytoplasmic organelles and in the fiber bundles of bones was also found. Also, the presence of collagen fibers as pathological condition.

  11. A Conceptual Systems Model to Facilitate Hypothesis-driven Ecotoxicogenomics Research on the Teleost Brain-pituitary-gonadal Axis

    Science.gov (United States)

    This provides an overview of a novel open-source conceptuial model of molecular and biochemical pathways involved in the regulation of fish reproduction. Further, it provides concrete examples of how such models can be used to design and conduct hypothesis-driven "omics" experim...

  12. Kisspeptin Antagonists Reveal Kisspeptin 1 and Kisspeptin 2 Differential Regulation of Reproduction in the Teleost, Morone saxatilis.

    Science.gov (United States)

    Zmora, Nilli; Stubblefield, John David; Wong, Ten-Tsao; Levavi-Sivan, Berta; Millar, Robert Peter; Zohar, Yonathan

    2015-09-01

    The importance of kisspeptin in regulating vertebrate reproduction has been well established, but the exact mechanism continues to unfold. Unlike mammals, many lower vertebrates possess a dual kisspeptin system, Kiss1 and Kiss2. To decipher the roles of the kisspeptins in fish, we identified two potential kisspeptin antagonists, pep 234 and pep 359, by screening analogs for their ability to inactivate striped bass Kiss1 and Kiss2 receptors expressed in COS7 cells. Pep 234 (a mammalian KISS1 antagonist) antagonizes Kiss1r signaling activated by Kiss1 and Kiss2, and pep 359 (a novel analog) antagonizes Kiss2 activation of both receptors. In vitro studies using brain slices demonstrated that only Kiss2 can upregulate the expression of the hypophysiotropic gnrh1, which was subsequently diminished by pep 234 and pep 359. In primary pituitary cell cultures, the two antagonists revealed a complex network of putative endogenous and exogenous regulation by kisspeptin. While both kisspeptins stimulate Fsh expression and secretion, Kiss2 predominately induces Lh secretion. Pep 234 and 359 treatment of spawning males hindered sperm production. This effect was accompanied with decreased brain gnrh1 and gnrh2 mRNA levels and peptide content in the pituitary, and increased levels of pituitary Lh, probably due to attenuation of Lh release. Strikingly, the mRNA levels of arginine-vasotocin, the neurons of which in the preoptic area coexpress kiss2r, were dramatically reduced by the antagonists. Our results demonstrate differential actions of Kiss1 and Kiss2 systems along the hypothalamic-pituitary axis and interactions with other neuropeptides, and further reinforce the importance of kisspeptin in the execution of spawning. © 2015 by the Society for the Study of Reproduction, Inc.

  13. Acute effects of cadmium on osmoregulation of the freshwater teleost Prochilodus lineatus: Enzymes activity and plasma ions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandre O.F. da [Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, UEL, Londrina (Brazil); Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, UEL, Londrina (Brazil); Centro de Ciências Humanas e da Educação, UENP, Jacarezinho (Brazil); Martinez, Cláudia B.R., E-mail: cbueno@uel.br [Departamento de Ciências Fisiológicas, Laboratório de Ecofisiologia Animal, UEL, Londrina (Brazil); Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, UEL, Londrina (Brazil)

    2014-11-15

    Highlights: • Cd effects were evaluated on plasma ions and ATPases of Prochilodus lineatus. • Fish were exposed to 1 and 10 μg Cd L{sup −1} for 24 and 96 h. • Na{sup +}/K{sup +}-ATPase and carbonic anhydrase decreased in gills and kidney after Cd exposure. • Gill Ca{sup 2+}-ATPase and plasma Ca{sup 2+} decreased after Cd exposure. • Cd concentrations set by Brazilian guidelines affect Ca{sup 2+} regulation of P. lineatus. - Abstract: Cadmium (Cd) is a trace element that is very toxic to fish. It is commonly found in surface waters contaminated with industrial effluents. When dissolved in water, Cd can rapidly cause physiological changes in the gills and kidneys of freshwater fish. The objective of this study was to evaluate the acute effects of Cd on the osmoregulation of the Neotropical fish Prochilodus lineatus. Juvenile fish were exposed to Cd at two concentrations [1 (Cd1) and 10 (Cd10) μg L{sup −1}] for 24 and 96 h. The effects of Cd were evaluated through the analysis of ions (Na{sup +}, K{sup +}, Ca{sup 2+}, and Cl{sup −}) and plasma osmolality, and by measuring the activities of enzymes involved in osmoregulation obtained from the gills and kidney. Fish exposed to Cd for 24 and 96 h showed a decrease in Na{sup +}/K{sup +}-ATPase activity in the gills and kidney. The activity of carbonic anhydrase decreased in the gills after 24 h and in both tissues after 96 h of Cd exposure. The gill Ca{sup 2+}-ATPase activity also decreased with Cd exposure, with a concomitant drop in the plasma concentration of Ca{sup 2+}. Despite the hypocalcemia, there were no changes in the concentration of the ions Na{sup +}, K{sup +}, and Cl{sup −} or in plasma osmolality. Among the enzymes involved in ion transport, H{sup +}-ATPase was the only enzyme that showed increased activity in gills, whereas its activity in kidney remained unchanged. The results of this study demonstrate that waterborne Cd at the maximum concentrations set by Brazilian guidelines for freshwater affects the gills and kidney functions of P. lineatus. Acute exposure to Cd resulted in the decrease of the activity of enzymes, which culminated with the loss of the fish's ability to regulate the levels of calcium in the blood, leading to hypocalcemia.

  14. Acute effects of cadmium on osmoregulation of the freshwater teleost Prochilodus lineatus: Enzymes activity and plasma ions

    International Nuclear Information System (INIS)

    Silva, Alexandre O.F. da; Martinez, Cláudia B.R.

    2014-01-01

    Highlights: • Cd effects were evaluated on plasma ions and ATPases of Prochilodus lineatus. • Fish were exposed to 1 and 10 μg Cd L −1 for 24 and 96 h. • Na + /K + -ATPase and carbonic anhydrase decreased in gills and kidney after Cd exposure. • Gill Ca 2+ -ATPase and plasma Ca 2+ decreased after Cd exposure. • Cd concentrations set by Brazilian guidelines affect Ca 2+ regulation of P. lineatus. - Abstract: Cadmium (Cd) is a trace element that is very toxic to fish. It is commonly found in surface waters contaminated with industrial effluents. When dissolved in water, Cd can rapidly cause physiological changes in the gills and kidneys of freshwater fish. The objective of this study was to evaluate the acute effects of Cd on the osmoregulation of the Neotropical fish Prochilodus lineatus. Juvenile fish were exposed to Cd at two concentrations [1 (Cd1) and 10 (Cd10) μg L −1 ] for 24 and 96 h. The effects of Cd were evaluated through the analysis of ions (Na + , K + , Ca 2+ , and Cl − ) and plasma osmolality, and by measuring the activities of enzymes involved in osmoregulation obtained from the gills and kidney. Fish exposed to Cd for 24 and 96 h showed a decrease in Na + /K + -ATPase activity in the gills and kidney. The activity of carbonic anhydrase decreased in the gills after 24 h and in both tissues after 96 h of Cd exposure. The gill Ca 2+ -ATPase activity also decreased with Cd exposure, with a concomitant drop in the plasma concentration of Ca 2+ . Despite the hypocalcemia, there were no changes in the concentration of the ions Na + , K + , and Cl − or in plasma osmolality. Among the enzymes involved in ion transport, H + -ATPase was the only enzyme that showed increased activity in gills, whereas its activity in kidney remained unchanged. The results of this study demonstrate that waterborne Cd at the maximum concentrations set by Brazilian guidelines for freshwater affects the gills and kidney functions of P. lineatus. Acute exposure to Cd resulted in the decrease of the activity of enzymes, which culminated with the loss of the fish's ability to regulate the levels of calcium in the blood, leading to hypocalcemia

  15. Saccular Transcriptome Profiles of the Seasonal Breeding Plainfin Midshipman Fish (Porichthys notatus), a Teleost with Divergent Sexual Phenotypes.

    Science.gov (United States)

    Faber-Hammond, Joshua; Samanta, Manoj P; Whitchurch, Elizabeth A; Manning, Dustin; Sisneros, Joseph A; Coffin, Allison B

    2015-01-01

    Acoustic communication is essential for the reproductive success of the plainfin midshipman fish (Porichthys notatus). During the breeding season, type I males use acoustic cues to advertise nest location to potential mates, creating an audible signal that attracts reproductive females. Type II (sneaker) males also likely use this social acoustic signal to find breeding pairs from which to steal fertilizations. Estrogen-induced changes in the auditory system of breeding females are thought to enhance neural encoding of the advertisement call, and recent anatomical data suggest the saccule (the main auditory end organ) as one possible target for this seasonal modulation. Here we describe saccular transcriptomes from all three sexual phenotypes (females, type I and II males) collected during the breeding season as a first step in understanding the mechanisms underlying sexual phenotype-specific and seasonal differences in auditory function. We used RNA-Seq on the Ion Torrent platform to create a combined transcriptome dataset containing over 79,000 assembled transcripts representing almost 9,000 unique annotated genes. These identified genes include several with known inner ear function and multiple steroid hormone receptors. Transcripts most closely matched to published genomes of nile tilapia and large yellow croaker, inconsistent with the phylogenetic relationship between these species but consistent with the importance of acoustic communication in their life-history strategies. We then compared the RNA-Seq results from the saccules of reproductive females with a separate transcriptome from the non-reproductive female phenotype and found over 700 differentially expressed transcripts, including members of the Wnt and Notch signaling pathways that mediate cell proliferation and hair cell addition in the inner ear. These data constitute a valuable resource for furthering our understanding of the molecular basis for peripheral auditory function as well as a range of future midshipman and cross-species comparative studies of the auditory periphery.

  16. Saccular Transcriptome Profiles of the Seasonal Breeding Plainfin Midshipman Fish (Porichthys notatus, a Teleost with Divergent Sexual Phenotypes.

    Directory of Open Access Journals (Sweden)

    Joshua Faber-Hammond

    Full Text Available Acoustic communication is essential for the reproductive success of the plainfin midshipman fish (Porichthys notatus. During the breeding season, type I males use acoustic cues to advertise nest location to potential mates, creating an audible signal that attracts reproductive females. Type II (sneaker males also likely use this social acoustic signal to find breeding pairs from which to steal fertilizations. Estrogen-induced changes in the auditory system of breeding females are thought to enhance neural encoding of the advertisement call, and recent anatomical data suggest the saccule (the main auditory end organ as one possible target for this seasonal modulation. Here we describe saccular transcriptomes from all three sexual phenotypes (females, type I and II males collected during the breeding season as a first step in understanding the mechanisms underlying sexual phenotype-specific and seasonal differences in auditory function. We used RNA-Seq on the Ion Torrent platform to create a combined transcriptome dataset containing over 79,000 assembled transcripts representing almost 9,000 unique annotated genes. These identified genes include several with known inner ear function and multiple steroid hormone receptors. Transcripts most closely matched to published genomes of nile tilapia and large yellow croaker, inconsistent with the phylogenetic relationship between these species but consistent with the importance of acoustic communication in their life-history strategies. We then compared the RNA-Seq results from the saccules of reproductive females with a separate transcriptome from the non-reproductive female phenotype and found over 700 differentially expressed transcripts, including members of the Wnt and Notch signaling pathways that mediate cell proliferation and hair cell addition in the inner ear. These data constitute a valuable resource for furthering our understanding of the molecular basis for peripheral auditory function as well as a range of future midshipman and cross-species comparative studies of the auditory periphery.

  17. Stress, nutrition and parental care in a teleost fish: exploring mechanisms with supplemental feeding and cortisol manipulation.

    Science.gov (United States)

    Zolderdo, A J; Algera, D A; Lawrence, M J; Gilmour, K M; Fast, M D; Thuswaldner, J; Willmore, W G; Cooke, S J

    2016-04-15

    Parental care is an essential life-history component of reproduction for many animal species, and it entails a suite of behavioural and physiological investments to enhance offspring survival. These investments can incur costs to the parent, reducing their energetic and physiological condition, future reproductive capabilities and survival. In fishes, relatively few studies have focused on how these physiological costs are mediated. Male smallmouth bass provide parental care for developing offspring until the brood reaches independence. During this energetically demanding life stage, males cease active foraging as they vigorously defend their offspring. Experimental manipulation of cortisol levels (via implantation) and food (via supplemental feeding) in parental males was used to investigate the fitness consequences of parental care. Improving the nutritional condition of nest-guarding males increased their reproductive success by reducing premature nest abandonment. However, supplemental feeding and cortisol treatment had no effect on parental care behaviours. Cortisol treatment reduced plasma lymphocyte numbers, but increased neutrophil and monocyte concentrations, indicating a shift in immune function. Supplemental feeding improved the physiological condition of parental fish by reducing the accumulation of oxidative injury. Specifically, supplemental feeding reduced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) on DNA nucleotides. Increasing the nutritional condition of parental fish can reduce the physiological cost associated with intensive parental activity and improve overall reproductive success, illustrating the importance of nutritional condition as a key modulator of parental fitness. © 2016. Published by The Company of Biologists Ltd.

  18. Effects of X-irradiation and thymectomy on the immune response of the marine teleost, Sebastiscus marmoratus

    International Nuclear Information System (INIS)

    Nakanishi, T.

    1986-01-01

    Effects of X-irradiation and thymectomy on the immune response of the rock fish, S. marmoratus were studied. Animals were thymectomized and irradiated at the dose of 2000 R. In non-thymectomized and irradiated fish, injected with SRBC one week after irradiation, antibody production was completely suppressed and they required twice the time for rejection of scales allografted three days after irradiation. On the other hand, fish which were irradiated four days after thymectomy and injected one week after irradiation, showed a fairly high level of antibody, although, in the allograft rejection, no significant difference was observed when compared to the irradiated fish. Furthermore, animals thymectomized, irradiated and autoimplanted showed higher production of antibody when immunized three months after irradiation compared to matched controls. In the same manner, in the allograft rejection, a slight restoration was found in fish reconstituted with a non-irradiated thymus. From these results, it is considered that, as in mammals, the adult thymus of fish plays an important role in recovery from the damage to the immune system caused by irradiation. Furthermore, a combination of X-irradiation and thymectomy suggests that suppressor T-cells which are resistant to X-rays exist in the fish thymus

  19. Blood Volume, Plasma Volume and Circulation Time in a High-Energy-Demand Teleost, the Yellowfin Tuna (Thunnus Albacares)

    DEFF Research Database (Denmark)

    Brill, R.W.; Cousins, K.L.; Jones, D.R.

    1998-01-01

    We measured red cell space with 51Cr-labeled red blood cells, and dextran space with 500 kDa fluorescein-isothiocyanate-labeled dextran (FITC-dextran), in two groups of yellowfin tuna (Thunnus albacares). Red cell space was 13.8+/-0.7 ml kg-1 (mean +/- s.e.m.) Assuming a whole- body hematocrit...... for albacore (Thunnus alalunga, 82-197 ml kg-1). Plasma volume within the primary circulatory system (calculated from the 51Cr-labeled red blood cell data) was 32.9+/-2.3 ml kg-1. Dextran space was 37.0+/-3.7 ml kg-1. Because 500 kDa FITC-dextran appeared to remain within the vascular space, these data imply...

  20. Mycobacterium stephanolepidis sp. nov., a rapidly growing species related to Mycobacterium chelonae, isolated from marine teleost fish, Stephanolepis cirrhifer.

    Science.gov (United States)

    Fukano, Hanako; Wada, Shinpei; Kurata, Osamu; Katayama, Kinya; Fujiwara, Nagatoshi; Hoshino, Yoshihiko

    2017-08-01

    A previously undescribed rapidly growing, non-pigmented mycobacterium was identified based on biochemical and nucleic acid analyses, as well as growth characteristics. Seven isolates were cultured from samples collected from five thread-sail filefish (Stephanolepis cirrhifer) and two farmed black scraper (Thamnaconus modestus). Bacterial growth occurred at 15-35 °C on Middlebrook 7H11 agar. The bacteria were positive for catalase activity at 68 °C and urease activity, intermediate for iron uptake, and negative for Tween 80 hydrolysis, nitrate reduction, semi-quantitative catalase activity and arylsulfatase activity at day 3. No growth was observed on Middlebrook 7H11 agar supplemented with picric acid, and very little growth was observed in the presence of 5 % NaCl. α- and α'-mycolates were identified in the cell walls, and a unique profile of the fatty acid methyl esters and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiles of the protein and cell-wall lipids were acquired. Sequence analysis revealed that the seven isolates shared identical sequences for the 16S rRNA, rpoB, hsp65, recA and sodA genes. Phylogenetic analysis of the five gene sequences confirmed that the isolates were unique, but closely related to Mycobacterium chelonae. Antibiotic susceptibility testing revealed the minimum inhibitory concentration (MIC) of clarithromycin against this novel species was Mycobacterium salmoniphilum. The hsp65 PCR restriction enzyme analysis pattern differed from those of M. chelonae and M. salmoniphilum. Based on these findings, the name Mycobacterium stephanolepidis sp. nov. is proposed for this novel species, with the type strain being NJB0901 T (=JCM 31611 T =KCTC 39843 T ).

  1. Ontogeny of the thymus in a teleost fish, Cyprinus carpio L.: developing thymocytes in the epithelial microenvironment.

    Science.gov (United States)

    Romano, N; Taverne-Thiele, A J; Fanelli, M; Baldassini, M R; Abelli, L; Mastrolia, L; Van Muiswinkel, W B; Rombout, J H

    1999-01-01

    A monoclonal antibody, WCL9, specific for membrane molecules of a thymocyte subpopulation was used to detect these cells in situ during the ontogeny of thymus. Cryo-sections revealed WCL9+ cells in the rudiment of the thymus (day 4 post fertilization); thereafter, the positive cells were observed exclusively in the cortex from the first appearance of thymic regionalization (week 4 post fertilization) until adult age. Whole-mount immunostaining of the thymus with WCL9 revealed the three-dimensional structure of the cortex by specific staining. The presence and distribution of apoptotic cells during thymus development was studied by in situ end-labelling of fragmented DNA. From week 4 post fertilization onwards, apoptotic cells were more frequently detected in the cortex than medulla, suggesting a continuous selection of thymocytes in the cortex. Ultrastructural studies confirmed the presence of numerous cortical apoptotic cells inside macrophages. Electron microscopy provided evidence for the existence of epithelial heterogeneity in the thymus. During the ontogeny, the differentiation of epithelial cells was followed from the first weeks until the juvenile age. Cell types were classified on the basis of their localization and cytological characteristics as: i) limiting epithelial cells located in subcapsular, perivascular and peritrabecular zones; ii) reticular epithelial cells situated in medullary and cortical zones; iii) nurse-like cells at the border between the cortex and medulla, iiii) Hassall's body-like structures localized in the medulla. This study could suggest the occurrence of a wide range of lympho-epithelial interactions throughout thymocytes differentiation.

  2. Pharmacological characterization of the oxytocic peptides in the pituitary of a marine teleost fish (pollachius virens) (1961)

    International Nuclear Information System (INIS)

    Maetz, J.; Morel, F.

    1961-01-01

    Demonstration of the existence, in the neurohypophysis of a marine fish (pollachius virens), of an oxytocic-active peptide different to the oxytocin in mammals and to the arginine vasotocin. (authors) [fr

  3. Post-duplication charge evolution of phosphoglucose isomerases in teleost fishes through weak selection on many amino acid sites

    Directory of Open Access Journals (Sweden)

    Sato Yukuto

    2007-10-01

    Full Text Available Abstract Background The partitioning of ancestral functions among duplicated genes by neutral evolution, or subfunctionalization, has been considered the primary process for the evolution of novel proteins (neofunctionalization. Nonetheless, how a subfunctionalized protein can evolve into a more adaptive protein is poorly understood, mainly due to the limitations of current analytical methods, which can detect only strong selection for amino acid substitutions involved in adaptive molecular evolution. In this study, we employed a comparative evolutionary approach to this question, focusing on differences in the structural properties of a protein, specifically the electric charge, encoded by fish-specific duplicated phosphoglucose isomerase (Pgi genes. Results Full-length cDNA cloning, RT-PCR based gene expression analyses, and comparative sequence analyses showed that after subfunctionalization with respect to the expression organ of duplicate Pgi genes, the net electric charge of the PGI-1 protein expressed mainly in internal tissues became more negative, and that of PGI-2 expressed mainly in muscular tissues became more positive. The difference in net protein charge was attributable not to specific amino acid sites but to the sum of various amino acid sites located on the surface of the PGI molecule. Conclusion This finding suggests that the surface charge evolution of PGI proteins was not driven by strong selection on individual amino acid sites leading to permanent fixation of a particular residue, but rather was driven by weak selection on a large number of amino acid sites and consequently by steady directional and/or purifying selection on the overall structural properties of the protein, which is derived from many modifiable sites. The mode of molecular evolution presented here may be relevant to various cases of adaptive modification in proteins, such as hydrophobic properties, molecular size, and electric charge.

  4. Role of catecholamines and nitric oxide on pigment displacement of the chromatophores of freshwater snakehead teleost fish, Channa punctatus.

    Science.gov (United States)

    Biswas, Saikat P; Jadhao, Arun G; Palande, Nikhil V

    2014-04-01

    We are reporting for the first time that the catecholamines (adrenaline and noradrenaline) inhibit the effect of nitric oxide (NO) on melanosome dispersion in freshly isolated scales of the freshwater snakehead fish, Channa punctatus. We studied the effect of NO and catecholamines on the pigment displacement by observing the changes in the melanophore index. The scales when treated with solution containing NO donor sodium nitroprusside (SNP) showed dispersion of melanosomes, whereas NO synthase blocker N-omega-Nitro-L-arginine suppresses this action of SNP. Treatment with adrenaline and noradrenaline on the isolated scales caused aggregation of melanosomes. Scales treated with solution containing catecholamines and SNP resulted in aggregation of melanosomes suggesting that catecholamines mask the effect of SNP. These results suggest that the catecholamines are inhibiting the effect of NO and causing the aggregation of the melanosomes may be via surface receptors.

  5. 5-HT receptor subtypes as key targets in mediating pigment dispersion within melanophores of teleost, Oreochromis mossambicus.

    Science.gov (United States)

    Salim, Saima; Ali, Ayesha S; Ali, Sharique A

    2013-02-01

    The presence of distinct class of 5-HT receptors in the melanophores of tilapia (Oreochromis mossambicus) is reported. The cellular responses to 5-HT (5-hydroxytryptamine), 5-HT(1), and 5-HT(2), agonists on isolated scale melanophores were observed with regard to pigment translocation within the cells. It was found that 5-HT exerted rapid and strong concentration dependent pigment granule dispersion within the melanophores. The threshold pharmacological dose of 5-HT that could elicit a measurable response was as low as 4.7×10(-12) M/L. Selective 5-HT(1) and 5-HT(2) agonists, sumatriptan and myristicin were investigated and resulted in dose-dependent pigment dispersion. The dispersing effects were effectively antagonized by receptor specific antagonists. It is suggested that 5-HT-induced physiological effects are mediated via distinct classes of receptors that possibly participate in modulation of pigmentary responses of the fish. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Branchial versus intestinal silver toxicity and uptake in the marine teleost Parophrys vetulus

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Wood, C. M.

    2001-01-01

    Exposure to elevated waterborne silver as AgNO3 (4.07 µM=448 µg l-1) in seawater resulted in osmoregulatory disturbance in the lemon sole (Parophrys vetulus). The main effects were increased plasma Na+ and Cl- concentrations which translated into increased plasma osmolality. Plasma Mg2+ levels were...

  7. Effects of sodium fluoride on MAPKs signaling pathway in the gills of a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Cao, Jinling; Chen, Jianjie; Wang, Jundong; Klerks, Paul; Xie, Lingtian

    2014-07-01

    Exposure to elevated levels of fluoride can cause a variety of adverse effects in fish. Previously we showed that fluoride causes injuries and apoptosis in the gills of Cyprinus carpio. In this study, the effects of fluoride on caspase-3 activity and on accumulation of proteins in the MAPKs pathways were evaluated using Western blotting and immunohistochemistry methods in vivo and in vitro. In vivo experiments showed that the caspase-3 activity increased with fluoride exposure level in a dose-dependent pattern Western blotting and immunohistochemistry results indicated that ERK relative activation tended to decrease as a function of fluoride exposure concentration. In contrast, relative activation of JNK increased with fluoride exposure level. Fluoride exposure did not appear to affect p38 activation. Furthermore, pretreatment of branchial cells with MAPK-specific inhibitors effectively prevented JNK induction and ERK inhibition, respectively, as well as reversed caspase-3 activity in fluoride-treated branchial cells. Our results indicate that activation of JNK and inactivation of ERK were caused by increased ROS and decreased antioxidant capacity in the gills of chronically exposed C. carpio described previously, which eventually caused the observed apoptosis in the fluoride-exposed gills and cells in C. carpio. JNK activation and ERK inactivation mechanism play a crucial role in gill impairment induced by chronic fluorosis. These findings contribute to a better understanding of the initial molecular and cellular events in the gill of fish chronically exposed to fluoride. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effects of fluoride on growth, body composition, and serum biochemical profile in a freshwater teleost, Cyprinus carpio.

    Science.gov (United States)

    Chen, Jianjie; Cao, Jinling; Wang, Jundong; Jia, Ruhui; Xue, Wenjuan; Li, Yundong; Luo, Yongju; Xie, Lingtian

    2013-10-01

    Fluoride is ubiquitously distributed in natural waters. Elevated fluoride may cause histopathological changes and induce oxidative stress in the gills of the common carp (Cyprinus carpio). The present study further evaluates the effects of fluoride on growth performance, body composition, and biochemical measurements of C. carpio. The results showed that food intake, growth, serum osmolality, body composition, and biochemical measures in the blood were affected by fluoride. Weight gain rate and specific growth rate in the exposed fish decreased compared with those of the control fish. Levels of crude protein and crude lipids were reduced in the fluoride-exposed fish. The major ion levels in the sera of fluoride-exposed fish were severely disturbed, resulting in a lower osmolality. All the biochemical parameters measured in the blood were affected by the exposure to fluoride. Total protein, albumin, globulin, and glucose in fish exposed to 63.6 mg/L, 77.7 mg/L, and 124.4 mg/L were lower than those in the control fish. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were markedly increased in exposed fish compared with control. Taken together, the data showed that exposure to fluoride caused a suite of detrimental effects in C. carpio, which might lead to a decrease in growth and food utilization efficiency. The results of the present study indicated that high levels of fluoride could pose a threat to carp in the field. © 2013 SETAC.

  9. Lethal toxicity of Lindane on a teleost fish, Anguilla anguilla from Albufera Lake (Spain): hardness and temperature effects.

    Science.gov (United States)

    Ferrando, M D; Almar, M M; Andreu, E

    1988-02-01

    This paper reports the results of toxicity tests conducted using Anguilla anguilla under three different water temperature (15, 22 and 29 degrees C) and two hardness regimes (250 and greater than 600 ppm CaCO3). The 96-h LC50 increased in the experimental medium (p less than 0.05) by an order of magnitude from 0.32 to 0.45 mg/L between 15 and 29 degrees C. However in the natural medium it is similar (p greater than 0.05) (0.54 to 0.55 mg/L) for these same temperatures. The toxicity of Lindane on eels increased when the water hardness decreased. The 24, 48, 72 and 96-h LC50 for this fish in both media is less at 15 degrees C (96-h LC50 = 0.32 and 0.55 mg/L) than at 29 degrees C (96-h LC50 = 0.45 and 0.55 mg/L). These results suggest that the toxicity of Lindane presents a negative temperature coefficient.

  10. The unique hemoglobin system of Pleuragramma antarcticum, an antarctic migratory teleost. Structure and function of the three components.

    Science.gov (United States)

    Tamburrini, M; D'Avino, R; Fago, A; Carratore, V; Kunzmann, A; Prisco, G

    1996-09-27

    Pleuragramma antarcticum (suborder Notothenioidei, family Nototheniidae) is the most abundant fish in the antarctic shelf. This pelagic species has a circum-antarctic distribution and is characterized by spawning migration. This species displays the highest multiplicity of major hemoglobins (three); the other notothenioids have a single one (except one species, having two) with relatively low oxygen affinity regulated by pH and organophosphates. The hemoglobins of P. antarcticum display strong Bohr and Root effects; however, they reveal important functional differences in subunit cooperativity and organophosphate regulation and, above all, in the response of oxygenation to temperature. Despite the substitution ValbetaE11 --> Ile found in Hb 2, which decreases the affinity in human mutants, the hemoglobins have similar oxygen affinity, higher than that of the other notothenioids. Hb 1 has the alpha chain in common with Hb 2 and the beta in common with Hb 3. The amino acid sequence of all four chains has been established. Thus the hematological features of P. antarcticum differ remarkably from those of antarctic notothenioids. This unique and sophisticated oxygen transport system may adequately meet the requirements of the unusual mode of life of this fish.

  11. Binding and movement of silver in the intestinal epithelium of a marine teleost fish, the European flounder (Platichthys flesus)

    DEFF Research Database (Denmark)

    Hogstrand, C.; Wood, C. M.; Bury, N.R.

    2002-01-01

    The intestine has been indicated as a site of waterborne silver toxicity in marine fish and chronic effects at the intestine have been observed at concentrations far below acutely toxic level. Thus, models of silver toxicity to marine fish need to consider the intestine as a biotic ligand....... The present study characterises binding of silver to the intestine of the European flounder (Platichthys flesus). Everted intestinal sacks were prepared and submersed in a solution mimicking the intestinal fluid of the fish at the acclimation salinity (21‰). Silver was added as 110mAgNO3 or 110mAgNO3/AgNO3...... mixtures at concentrations ranging from 1.6 to 950 nM total silver. Appearance of 110mAg was analysed in mucosal scrapings, muscle layers, and in the plasma saline on the serosal side of the intestine. The latter represented uptake into blood and other extra-intestinal compartments. Mucosal scrapings...

  12. Structure, attachment, replacement and growth of teeth in bluefish, Pomatomus saltatrix (Linnaeus, 1776), a teleost with deeply socketed teeth.

    Science.gov (United States)

    Bemis, William E; Giuliano, Anne; McGuire, Betty

    2005-01-01

    Tooth replacement poses many questions about development, pattern formation, tooth attachment mechanisms, functional morphology and the evolution of vertebrate dentitions. Although most vertebrate species have polyphyodont dentitions, detailed knowledge of tooth structure and replacement is poor for most groups, particularly actinopterygians. We examined the oral dentition of the bluefish, Pomatomus saltatrix, a pelagic and coastal marine predator, using a sample of 50 individuals. The oral teeth are located on the dentary and premaxillary bones, and we scored each tooth locus in the dentary and premaxillary bones using a four-part functional classification: absent (A), incoming (I), functional (F=fully ankylosed) or eroding (E). The homodont oral teeth of Pomatomus are sharp, deeply socketed and firmly ankylosed to the bone of attachment. Replacement is intraosseus and occurs in alternate tooth loci with long waves of replacement passing from rear to front. The much higher percentage of functional as opposed to eroding teeth suggests that replacement rates are low but that individual teeth are quickly lost once erosion begins. Tooth number increases ontogenetically, ranging from 15-31 dentary teeth and 15-39 premaxillary teeth in the sample studied. Teeth increase in size with every replacement cycle. Remodeling of the attachment bone occurs continuously to accommodate growth. New tooth germs originate from a discontinuous dental lamina and migrate from the lingual (dentary) or labial (premaxillary) epithelium through pores in the bone of attachment into the resorption spaces beneath the existing teeth. Pomatomus shares unique aspects of tooth replacement with barracudas and other scombroids and this supports the interpretation that Pomatomus is more closely related to scombroids than to carangoids.

  13. Detection of lymphocystis disease virus in Japanese flounder Paralichthys olivaceus and other marine teleosts from northern China

    Science.gov (United States)

    Zhan, Wenbin; Li, Yongqin; Sheng, Xiuzhen; Xing, Jing; Tang, Xiaoqian

    2010-11-01

    We isolated a strain of lymphocystis disease virus (LCDV) from Japanese flounder ( Paralichthys olivaceus) cultured in northern China. Based on published sequences of major capsid protein (MCP) gene of LCDV-cn (GenBank: AF126405), we designed two primer sets P1/P2 and P3/P4. We then used one-step or nested PCR and in-situ hybridization (ISH) to detect LCDV and identify the target tissues or cells in infected Japanese flounder. The PCR products were positive in purified viral supernatant, skin nodules, gut, gill, kidney, spleen, stomach, heart, and liver of Japanese flounder. We compared the DNA sequence with 14 MCP nucleotide sequences from GenBank, including Megalocytivirus (OFIV and RSIV), Iridovirus (CzIV and WIV), Ranavirus (TFV and FV3), and Lymphocystivirus (8 LCDV). Based on the alignment, we confirmed the PCR product was from Lymphocystivirus (GenBank accession number DQ279090 (LCDV-HD)). Using ISH, we noted the presence of LCDV in the skin nodules, gut, gill, spleen, stomach, and heart of spontaneously infected Japanese flounders. We successfully amplified LCDV fragments from Schlegel’s black rockfish ( Sebastes schlegeli Higendorf), redwing sea robin ( Lepidotrigla microptera Günther) and turbot ( Scophthalmus maximus) using the one-step and nested PCR, suggesting the target genes can be widely detected in fish using this method.

  14. Hydrodynamic patterns from fast-starts in teleost fish and their possible relevance to predator-prey interactions.

    Science.gov (United States)

    Niesterok, Benedikt; Hanke, Wolf

    2013-02-01

    Fast-starts are distributed over a wide phylogenetic range of fish and are used for different purposes such as striking at prey or escaping from predators. Here we investigated 42 fast-starts of rainbow trouts (Oncorhynchus mykiss) elicited by a startle stimulus. We investigated the patterns of water movements left behind by the escaping fish and their possible value as a source of information to piscivorous predators that rely on hydrodynamic sensory systems. Particle image velocimetry (PIV) measurements revealed a temporal extension of up to 25.5 min and a spatial extension of up to 1.53 m (extrapolated) for a certain flow structure called jet 1, that is the flow produced by the tail fin. Duration and spatial extension of jet 2, the flow produced by the body, were on average lower, and both jets differed in size. The fish escaped in a mean direction approximately parallel to jet 1, and antiparallel to jet 2, with a range well above 200°. This study quantified the flow patterns generated by escaping fish and, as piscivorous predators would greatly benefit from being able to analyse these flow patterns, provides cues for the behavioural and physiological investigation of hydrodynamic sensory systems.

  15. Neuroendocrine and Immune Responses Undertake Different Fates following Tryptophan or Methionine Dietary Treatment: Tales from a Teleost Model

    Directory of Open Access Journals (Sweden)

    Rita Azeredo

    2017-09-01

    Full Text Available Methionine and tryptophan appear to be fundamental in specific cellular pathways involved in the immune response mechanisms, including stimulation of T-regulatory cells by tryptophan metabolites or pro-inflammatory effects upon methionine supplementation. Thus, the aim of this study was to evaluate the immunomodulatory effect of these amino acids on the inflammatory and neuroendocrine responses in juveniles of European seabass, Dicentrarchus labrax. To achieve this, goal fish were fed for 14 days methionine and tryptophan-supplemented diets (MET and TRP, respectively, 2× dietary requirement level or a control diet meeting the amino acids requirement levels (CTRL. Fish were sampled for immune status assessment and the remaining fish were challenged with intraperitoneally injected inactivated Photobacterium damselae subsp. piscicida and sampled either 4 or 24 h post-injection. Respiratory burst activity, brain monoamines, plasma cortisol, and immune-related gene expression showed distinct and sometimes opposite patterns regarding the effects of dietary amino acids. While neuroendocrine intermediates were not affected by any dietary treatment at the end of the feeding trial, both supplemented diets led to increased levels of plasma cortisol after the inflammatory insult, while brain monoamine content was higher in TRP-fed fish. Peripheral blood respiratory burst was higher in TRP-fed fish injected with the bacteria inoculum but only compared to those fed MET. However, no changes were detected in total antioxidant capacity. Complement factor 3 was upregulated in MET-fed fish but methionine seemed to poorly affect other genes expression patterns. In contrast, fish fed MET showed increased immune cells numbers both before and after immune challenge, suggesting a strong enhancing effect of methionine on immune cells proliferation. Differently, tryptophan effects on inflammatory transcripts suggested an inhibitory mode of action. This, together with a high production of brain monoamine and cortisol levels, suggests that tryptophan might mediate regulatory mechanisms of neuroendocrine and immune systems cooperation. Overall, more studies are needed to ascertain the role of methionine and tryptophan in modulating (stimulate or regulate fish immune and neuroendocrine responses.

  16. A survey of ichthyofauna of Lake Kanyaboli and other small waterbodies in Kenya: alternative refugia for endangered fish species

    OpenAIRE

    Maithya, J.

    1998-01-01

    In 1988, the World Conservation Union (WCU) Red Book of Endangered Species listed hundreds of endemic fishes of Lake Victoria under a single heading - "ENDANGERED". Most of the endemic native food fishes are either endangered or extinct. However, a survey of the fauna of Lake Kanyaboli, revealed that a few remaining samples of these native fishes are actually thriving. These include several unidentified Haplochromis spp., Oreochromis esculentus and Oreochromis variabilis. As a resul...

  17. Willy Wonka pole pedofiil / Alar Niineväli

    Index Scriptorium Estoniae

    Niineväli, Alar

    2005-01-01

    Tim Burtoni mängufilm "Charlie ja šokolaadivabrik" Roald Dahli samanimelise raamatu järgi : Ameerika Ühendriigid 2005. Võrreldud sama raamatu 1971.a. ekraniseeringuga "Willy Wonka & the Chocolate Factory" : režissöör Mel Stuart

  18. ISOLATION OF A CYTOCHROME P450 3A CDNA SEQUENCE (CYP3A30) FROM THE MARINE TELEOST AND PHYLOGENETIC ANALYSIS OF CYP3A GENES. (R827102)

    Science.gov (United States)

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

    Science.gov (United States)

    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...

  20. Two Virus-Induced MicroRNAs Known Only from Teleost Fishes Are Orthologues of MicroRNAs Involved in Cell Cycle Control in Humans

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Bela-Ong, Dennis; Jalali, Seyed Amir Hossein

    2015-01-01

    MicroRNAs (miRNAs) are similar to 22 base pair-long non-coding RNAs which regulate gene expression in the cytoplasm of eukaryotic cells by binding to specific target regions in mRNAs to mediate transcriptional blocking or mRNA cleavage. Through their fundamental roles in cellular pathways, gene...... regulation mediated by miRNAs has been shown to be involved in almost all biological phenomena, including development, metabolism, cell cycle, tumor formation, and host-pathogen interactions. To address the latter in a primitive vertebrate host, we here used an array platform to analyze the miRNA response...... regulation. Stimulation of fish cell cultures with the IFN inducer poly I:C accordingly upregulated the expression of miR-462 and miR-731, while no stimulatory effect on miR-191 and miR-425 expression was observed in human cell lines. Despite high sequence conservation, evolution has thus resulted...

  1. Distribution of cobalt 60 in a mollusc, a crustacean and a freshwater teleost: variations as a function of the source of pollution and during elimination

    International Nuclear Information System (INIS)

    Amiard, J.C.; Amiard-Triquet, C.

    1979-01-01

    57 Co, 58 Co and 60 Co are present in nuclear test debris as well as in effluents of the non-military nuclear industry. The stable isotope, which is a constituent of vitamin B 12 , has very important biological functions. For each species, three experiments were carried out: (1) starved animals were immersed in 60 Co-contaminated water; (2) animals were immersed in contaminated water and received radioactive food and (3) animals were placed in fresh water without any pollutant but received contaminated food. Radiation doses were calculated for contamination via both food and water. When 60 Co is taken up directly from water, the most contaminated organs are external ones, especially the shell of the snail Lymnaea palustris and the exoskeleton and feeding appendages of the crayfish Astacus leptodactylus. Contamination via food is responsible for a relatively greater accumulation of radiocobalt in internal organs. The cobalt content of muscles - that is to say the edible parts of crayfish and common carp Cyprinus carpio -is very low. The highest concentrations recorded are in the visceral mass of the snail, the digestive gland of the crayfish and the kidneys of the carp. Internal doses for these organs are considerably higher than those for entire animals. Therefore, as a result of 60 Co distribution, they are critical organs for the freshwater species. Except for the carp, external radiation is very weak compared with internal radiation. A strong retention of 60 Co is observed for the shell of L. palustris while the desorption of radiocobalt from the exoskeleton of A. leptodactylus is easier. In carp, the 60 Co taken up by the gut from food, as well as from water, is rapidly eliminated. (author)

  2. HSP90 and pCREB alterations are linked to mancozeb-dependent behavioral and neurodegenerative effects in a marine teleost

    Energy Technology Data Exchange (ETDEWEB)

    Zizza, Merylin [Comparative Neuroanatomy Laboratory, Biology, Ecology and Earth Science Department (DiBEST), University of Calabria, Arcavacata of Rende, 87036, CS (Italy); Di Lorenzo, Mariana; Laforgia, Vincenza [Department of Biology, Section of Evolutionary and Comparative Biology, University of Naples Federico II, 80134 Naples (Italy); Furia, Emilia; Sindona, Giovanni [Department of Chemistry and Chemical Technologies (DCTC), University of Calabria, Arcavacata of Rende, 87036, CS (Italy); Canonaco, Marcello [Comparative Neuroanatomy Laboratory, Biology, Ecology and Earth Science Department (DiBEST), University of Calabria, Arcavacata of Rende, 87036, CS (Italy); Facciolo, Rosa Maria, E-mail: rm.facciolo@unical.it [Comparative Neuroanatomy Laboratory, Biology, Ecology and Earth Science Department (DiBEST), University of Calabria, Arcavacata of Rende, 87036, CS (Italy)

    2017-05-15

    The pesticide mancozeb (mz) is recognized as a potent inducer of oxidative stress due to its ability to catalyze the production of reactive oxygen species plus inhibiting mitochondrial respiration thus becoming an environmental risk for neurodegenerative diseases. Despite numerous toxicological studies on mz have been directed to mammals, attention on marine fish is still lacking. Thus, it was our intention to evaluate neurobehavioral activities of ornate wrasses (Thalassoma pavo) exposed to 0.2 mg/l of mz after a preliminary screening test (0.07–0.3 mg/l). Treated fish exhibited an evident (p < 0.001) latency to reach T-maze arms (> 1000%) while exploratory attitudes (total arm entries) diminished (− 50%; p < 0.05) versus controls during spontaneous exploration tests. Moreover, they showed evident enhancements (+ 111%) of immobility in the cylinder test. Contextually, strong (− 88%; p < 0.01) reductions of permanence in light zone of the Light/Dark apparatus along with diminished crossings (− 65%) were also detected. Conversely, wrasses displayed evident enhancements (160%) of risk assessment consisting of fast entries in the dark side of this apparatus. From a molecular point of view, a notable activation (p < 0.005) of the brain transcription factor pCREB occurred during mz-exposure. Similarly, in situ hybridization supplied increased HSP90 mRNAs in most brain areas such as the lateral part of the dorsal telencephalon (Dl; + 68%) and valvula of the cerebellum (VCe; + 35%) that also revealed evident argyrophilic signals. Overall, these first indications suggest a possible protective role of the early biomarkers pCREB and HSP90 against fish toxicity. - Highlights: • Fish exposed to mancozeb exhibited an evident latency to reach T-maze arms. • Mancozeb caused immobility and reduction of explorative attitudes. • Fish exposed to mancozeb showed anxiogenic performances in the Light/Dark apparatus. • The brain of fish exposed to mancozeb supplied pCREB plus HSP90 mRNA up-regulations. • Some brain areas of fish exposed to mancozeb revealed an evident neurodegeneration.

  3. Digeneans from deep-sea marine teleosts off the Outer Hebrides, Scotland, including the description of Brachyenteron helicoleni sp. nov. (Zoogonidae)

    Czech Academy of Sciences Publication Activity Database

    Bray, R. A.; Kuchta, Roman

    2006-01-01

    Roč. 51, č. 3 (2006), s. 169-175 ISSN 1230-2821 R&D Projects: GA ČR GA524/04/0342; GA ČR GD524/03/H133; GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Lecithasteridae * Zoogonidae * Trifoliovarium allocytti Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.772, year: 2006

  4. Ultrastructure of the surface structures and haptor of Empleurosoma pyriforme (Ancyrocephalinae; Monopisthocotylea: Monogenea) from the gills of the teleost fish Therapon jarbua.

    Science.gov (United States)

    Ramasamy, P; Brennan, G P

    2000-02-01

    Infections with Empleurosoma pyriforme occur between successive secondary gill lamellae on both sides of the primary lamella of Therapon jarbua. The haptoral disc bears two pairs of anchors and a pair of connecting transverse bars. The attachment of the parasite to the host gill causes inflammation, erosion and degeneration of the gill epithelia. The ventral anchors consist of an inner core of irregularly arranged, electron-dense fibrils and a smooth outer core of electron-lucent fibrils, whereas the surface of the dorsal anchors is ridged. Both the dorsal and the ventral anchors may be extended or withdrawn. The connecting transverse bars consist of longitudinally arranged fibrils in an electron-dense matrix, whereas the tendons consist of fibrils, supported in a less electron-dense matrix, which interconnect the anchor erector-protractor muscles and the haptor muscles. Two types of perikarya are present. The less common type contain large multivesicular bodies and small electron-dense granules and are located only in the haptor region. The second and more common perikarya are present throughout the body surface. The cytoplasmic syncytium contains numerous electron-dense granules and electron-lucent vesicles. Beneath the syncytium, unicellular epidermal gland cells contain electron-dense granules. Neurones containing numerous electron-dense vesicles are present in the haptor region. Uniciliate presumed sensory receptors are distributed over the body surface. Groups of ciliated sensory structures are present in the forebody. Ciliated and non-ciliated presumed sensory receptors are present in the sleeve cavity of the anchors, on the haptor and in the vicinity of the oral apertures.

  5. Early life stress induces long-term changes in limbic areas of a teleost fish: the role of catecholamine systems in stress coping

    DEFF Research Database (Denmark)

    Vindas, Marco A.; Fokos, Stefanos; Pavlidis, Michail

    2018-01-01

    Early life stress (ELS) shapes the way individuals cope with future situations. Animals use cognitive flexibility to cope with their ever-changing environment and this is mainly processed in forebrain areas. We investigated the performance of juvenile gilthead seabream, previously subjected...... of post-stress response in the β2 adrenergic receptor expression and a downregulation in bdnf in the Dm3 of ELS fish, which together indicate an allostatic overload in their stress coping ability. ELS fish showed higher neuronal activity (cfos) post-acute stress in the hippocampus homologue (Dlv...

  6. Ovarian structure and oogenesis of the extremophile viviparous teleost Poecilia mexicana (Poeciliidae) from an active sulfur spring cave in Southern Mexico.

    Science.gov (United States)

    Torres-Martínez, Aarón; Hernández-Franyutti, Arlette; Uribe, Mari Carmen; Contreras-Sánchez, Wilfrido Miguel

    2017-12-01

    The structure of the ovary and oogenesis of Poecilia mexicana from an active sulfur spring cave is documented. Poecilia mexicana is the only poeciliid adapted to a subterranean environment with high hydrogen sulfide levels and extreme hypoxic conditions. Twenty females were captured throughout one year at Cueva del Azufre, located in the State of Tabasco in Southern Mexico. Ovaries were processed with histological techniques. P. mexicana has a single, ovoid ovary with ovigerous lamella that project to the ovarian lumen. The ovarian wall presents abundant loose connective tissue, numerous melanomacrophage centers and large blood vessels, possibly associated with hypoxic conditions. The germinal epithelium bordering the ovarian lumen contains somatic and germ cells forming cell nests projecting into the stroma. P. mexicana stores sperm in ovarian folds associated with follicles at different developmental phases. Oogenesis in P. mexicana consisted of the following stages: (i) oogonial proliferation, (ii) chromatin nucleolus, (iii) primary growth, subdivided into: (a) one nucleolus, (b) multiple nucleoli, (c) droplet oils-cortical alveoli steps; (iv) secondary growth, subdivided in: (a) early secondary growth, (b) late secondary growth, and (c) full grown. Follicular atresia was present in all stages of follicular development; it was characterized by oocyte degeneration, where follicle cells hypertrophy and differentiate in phagocytes. The ovary and oogenesis are similar to these seen in other poeciliids, but we found frequent atretic follicles, melanomacrophage centers, reduced fecundity and increased of offspring size. © 2017 Wiley Periodicals, Inc.

  7. Morphological, anatomical and histological studies on the olfactory organs and eyes of teleost fish: Anguilla anguilla in relation to its feeding habits

    Directory of Open Access Journals (Sweden)

    K.I. Atta

    2013-05-01

    The average olfactory surface area is about 590.9% of the retinal area. Thus A. anguilla is a macrosmatic species “nose-fish” in which olfaction plays an important role in its feeding habit. It is noticed that, the photoreceptor cell layer in A. anguilla (bottom feeder is made up only of rod cells.

  8. Hepatic retinoid levels in seven fish species (teleosts) from a tropical coastal lagoon receiving effluents from iron-ore mining and processing.

    Science.gov (United States)

    Pereira, Adriana A; van Hattum, Bert; Brouwer, Abraham

    2012-02-01

    The present study was undertaken to investigate the possible effects of Fe and trace element exposure on hepatic levels of retinoids in seven fish species. Concentrations of retinoids were measured in fish collected from a coastal lagoon in Brazil that receives effluents from an iron-ore mining and processing plant. Fish from nearby coastal lagoons were also included to assess possible differences related to chemical exposure. Results indicated considerable differences in hepatic retinoid composition among the various species investigated. The most striking differences were in retinol and derivative-specific profiles and in didehydro retinol and derivative-specific profiles. The Perciformes species Geophagus brasiliensis, Tilapia rendalli, Mugil liza, and Cichla ocellaris and the Characiforme Hoplias malabaricus were characterized as retinol and derivative-specific, while the Siluriformes species Hoplosternum littorale and Rhamdia quelen were didehydro retinol and derivative-specific fish species. A negative association was observed between Al, Pb, As, and Cd and hepatic didehydro retinoid levels. Fish with higher levels of hepatic Fe, Cu, and Zn showed unexpectedly significant positive correlations with increased hepatic retinol levels. This finding, associated with the positive relationships between retinol and retinyl palmitate with lipid peroxidation, may suggest that vitamin A is mobilized from other tissues to increase hepatic antioxidant levels for protection against oxidative damage. These data show significant but dissimilar associations between trace element exposure and hepatic retinoid levels in fish species exposed to iron-ore mining and processing effluents, without apparent major impacts on fish health and condition. Copyright © 2011 SETAC.

  9. Leptin stimulates hepatic growth hormone receptor and insulin-like growth factor gene expression in a teleost fish, the hybrid striped bass.

    Science.gov (United States)

    Won, Eugene T; Douros, Jonathan D; Hurt, David A; Borski, Russell J

    2016-04-01

    Leptin is an anorexigenic peptide hormone that circulates as an indicator of adiposity in mammals, and functions to maintain energy homeostasis by balancing feeding and energy expenditure. In fish, leptin tends to be predominantly expressed in the liver, another important energy storing tissue, rather than in fat depots as it is in mammals. The liver also produces the majority of circulating insulin-like growth factors (IGFs), which comprise the mitogenic component of the growth hormone (GH)-IGF endocrine growth axis. Based on similar regulatory patterns of leptin and IGFs that we have documented in previous studies on hybrid striped bass (HSB: Morone saxatilis×Morone chrysops), and considering the co-localization of these peptides in the liver, we hypothesized that leptin might regulate the endocrine growth axis in a manner that helps coordinate somatic growth with energy availability. Using a HSB hepatocyte culture system to simulate autocrine or paracrine exposure that might occur within the liver, this study examines the potential for leptin to modulate metabolism and growth through regulation of IGF gene expression directly, or indirectly through the regulation of GH receptors (GHR), which mediate GH-induced IGF expression. First, we verified that GH (50nM) has a classical stimulatory effect on IGF-1 and additionally show it stimulates IGF-2 transcription in hepatocytes. Leptin (5 and/or 50nM) directly stimulated in vitro GHR2 gene expression within 8h of exposure, and both GHR1 and GHR2 as well as IGF-1 and IGF-2 gene expression after 24h. Cells were then co-incubated with submaximal concentrations of leptin and GH (25nM each) to test if they had a synergistic effect on IGF gene expression, possibly through increased GH sensitivity following GHR upregulation by leptin. In combination, however, the treatments only had an additive effect on stimulating IGF-1 mRNA despite their capacity to increase GHR mRNA abundance. This suggests that leptin's stimulatory effect on GHRs may be limited to enhancing transcription or mRNA stability rather than inducing full translation of functional receptors, at least within a 24-h time frame. Finally, leptin was injected IP (100ng/g and 1μg/gBW) to test the in vivo regulation of hepatic IGF-1 and GHR1 gene expression. The 100ng/g BW leptin dose significantly upregulated in vivo IGF-1 mRNA levels relative to controls after 24h of fasting, but neither dosage was effective at regulating GHR1 gene expression. These studies suggest that stimulation of growth axis component transcripts by leptin may be an important mechanism for coordinating somatic growth with nutritional state in these and perhaps other fish or vertebrates, and represent the first evidence of leptin regulating GHRs in vertebrates. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. The Relationship between the Ionic Composition of the Environment and the Secretory Activity of the Endocrine Cell Types of Stannius Corpuscles in the Teleost Gasterosteus aculeatus

    NARCIS (Netherlands)

    Wendelaar Bonga, S.E.; Greven, J.A.A.; Veenhuis, M.

    1976-01-01

    The corpuscles of Stannius of threespined sticklebacks contain two glandular cell types of presumed endocrine nature. To elucidate the function of both cell types the secretory activity of the cells was studied in fully adapted seawater and freshwater fishes and in specimens transferred from sea

  11. Effect of tributyltin on adenylate content and enzyme activities of teleost sperm: a biochemical approach to study the mechanisms of toxicant reduced spermatozoa motility.

    Science.gov (United States)

    Rurangwa, E; Biegniewska, A; Slominska, E; Skorkowski, E F; Ollevier, F

    2002-03-01

    The effects of tributyltin (TBT) on the energy metabolism and motility of fish spermatozoa were investigated in vitro in African catfish and common carp. A significant (PTBT for 24 h. Exposure of catfish spermatozoa to 2.7-27 microg/l TBT caused an instant decrease in ATP content. In the presence of 27 microg/l TBT approximately 55% of the initial ATP concentration in catfish semen was lost after 60 min incubation while AMP concentrations increased and the total adenine nucleotide (TAN) pool remained unchanged. The reduction in sperm ATP levels could not be attributed to cell death since viability decreased only slightly over the period of exposure. In carp by contrast, none of the adenylates concentrations studied (ATP, ADP and AMP) were affected by TBT exposure at any experimental condition. However, carp sperm motility was significantly reduced by exposure to 2.7 microg/l TBT. Among the enzymes investigated only lactate dehydrogenase (LDH) in catfish sperm was significantly (PTBT treatment with a reduction in activity of approximately 75%. Compared with carp sperm before TBT exposure, that of catfish had lower adenylate contents and overall lower enzymatic activities; this explains its slower sperm velocity and shorter duration of movement as measured by computer assisted sperm analysis (CASA). The present in vitro study shows that catfish spermatozoa are more sensitive to TBT exposure (and probably to other toxicants) than those of carp.

  12. HSP90 and pCREB alterations are linked to mancozeb-dependent behavioral and neurodegenerative effects in a marine teleost

    International Nuclear Information System (INIS)

    Zizza, Merylin; Di Lorenzo, Mariana; Laforgia, Vincenza; Furia, Emilia; Sindona, Giovanni; Canonaco, Marcello; Facciolo, Rosa Maria

    2017-01-01

    The pesticide mancozeb (mz) is recognized as a potent inducer of oxidative stress due to its ability to catalyze the production of reactive oxygen species plus inhibiting mitochondrial respiration thus becoming an environmental risk for neurodegenerative diseases. Despite numerous toxicological studies on mz have been directed to mammals, attention on marine fish is still lacking. Thus, it was our intention to evaluate neurobehavioral activities of ornate wrasses (Thalassoma pavo) exposed to 0.2 mg/l of mz after a preliminary screening test (0.07–0.3 mg/l). Treated fish exhibited an evident (p < 0.001) latency to reach T-maze arms (> 1000%) while exploratory attitudes (total arm entries) diminished (− 50%; p < 0.05) versus controls during spontaneous exploration tests. Moreover, they showed evident enhancements (+ 111%) of immobility in the cylinder test. Contextually, strong (− 88%; p < 0.01) reductions of permanence in light zone of the Light/Dark apparatus along with diminished crossings (− 65%) were also detected. Conversely, wrasses displayed evident enhancements (160%) of risk assessment consisting of fast entries in the dark side of this apparatus. From a molecular point of view, a notable activation (p < 0.005) of the brain transcription factor pCREB occurred during mz-exposure. Similarly, in situ hybridization supplied increased HSP90 mRNAs in most brain areas such as the lateral part of the dorsal telencephalon (Dl; + 68%) and valvula of the cerebellum (VCe; + 35%) that also revealed evident argyrophilic signals. Overall, these first indications suggest a possible protective role of the early biomarkers pCREB and HSP90 against fish toxicity. - Highlights: • Fish exposed to mancozeb exhibited an evident latency to reach T-maze arms. • Mancozeb caused immobility and reduction of explorative attitudes. • Fish exposed to mancozeb showed anxiogenic performances in the Light/Dark apparatus. • The brain of fish exposed to mancozeb supplied pCREB plus HSP90 mRNA up-regulations. • Some brain areas of fish exposed to mancozeb revealed an evident neurodegeneration.

  13. Redescriptions of two species of Lepeophtheirus (Copepoda, Siphonostomatoida, Caligidae parasitic on teleost marine fishes from the coastal zone of the State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    José Luis Luque

    2000-12-01

    Full Text Available Two species of Lepeophtheirus Nordmann, 1832 parasitic on the ariid fish Netuma barba Lacépède, 1803, and the bothiid fish Paralichthys sp. from the coastal zone of the State of Rio de Janeiro, are redescribed and illustrated: L. bagri Dana, 1852, and L. monacanthus Heller, 1865. New junior synonyms for these species are proposed: L. marginatus syn.n., L. christianensis syn.n. and L. platensis syn.n. of L. bagri and L. unispinosus syn.n. of L. monacanthus.

  14. Tapeworms (Cestoda: Proteocephalidea) of teleost fi shes from the Amazon River in Peru: additional records as an evidence of unexplored species diversity

    Czech Academy of Sciences Publication Activity Database

    de Chambrier, A.; Kuchta, Roman; Scholz, Tomáš

    2015-01-01

    Roč. 122, č. 1 (2015), s. 149-163 ISSN 0035-418X R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Catfish * freshwater fish * Siluriformes * Peru * Pimelodidae * Amazonia * species diversity * faunal survey Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.431, year: 2015

  15. Acute toxicity of azadirachtin to a teleost, Heteropneustes fossilis - doi: 10.4025/actascibiolsci.v34i2.9455

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Srivastav

    2012-03-01

    Full Text Available The acute static renewal test of a botanical pesticide - azadirachtin for the freshwater catfish, Heteropneustes fossilis has been performed to determine the LC50 values at different exposure period. The LC50 values at various exposure periods are 173.06 mg L-1 for 24h; 80.69 mg L-1 for 48h; 58.57 mg L-1 for 72h and 52.35 mg L-1 for 96h. The upper confidence limits were 196.87, 86.91, 79.20 and 70.04 mg L-1 for 24, 48, 72 and 96 h and lower confidence limits were 154.01, 74.24, 37.33 and 33.83 mg L-1, respectively. These results indicate that azadirachtin exposure to the fish caused toxic effects.

  16. Sexual dimorphic expression of DMRT1 and Sox9a during gonadal differentiation and hormone-induced sex reversal in the teleost fish Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Kobayashi, Tohru; Kajiura-Kobayashi, Hiroko; Guan, Guijun; Nagahama, Yoshitaka

    2008-01-01

    We examined the expression profiles of tDMRT1 and Sox9a during gonadal sex differentiation and hormone-induced sex reversal. tDMRT1 was detected in the gonial germ-cell-surrounding cells in XY fry specifically before the appearance of any signs of morphological sex differentiation, that is, sex differences in germ cell number and histogenesis, such as differentiation into intratesticular efferent duct or ovarian cavity. The signals became localized in the Sertoli and epithelial cells comprising the efferent duct during gonadal differentiation. After the induction of XY sex reversal with estrogen, tDMRT1 decreased and then disappeared completely. In contrast, tDMRT1 was expressed in the germ-cell-surrounding cells in XX sex reversal with androgen. On the other hand, Sox9a did not show sexual dimorphism before the appearance of sex differences in histogenesis and was not expressed in the efferent duct in the testis. These results suggest that tDMRT1 is a superior testicular differentiation marker in tilapia.

  17. Isolation and characterisation of mRNA encoding the salmon- and chicken-II type gonadotrophin-releasing hormones in the teleost fish Rutilus rutilus (Cyprinidae).

    Science.gov (United States)

    Penlington, M C; Williams, M A; Sumpter, J P; Rand-Weaver, M; Hoole, D; Arme, C

    1997-12-01

    The complementary DNAs (cDNA) encoding the [Trp7,Leu8]-gonadotrophin-releasing hormone (salmon-type GnRH; sGnRH:GeneBank accession no. u60667) and the [His5,Trp7,Tyr8]-GnRH (chicken-II-type GnRH; cGnRH-II: GeneBank accession no. u60668) precursor in the roach (Rutilus rutilus) were isolated and sequenced following reverse transcription and rapid amplification of cDNA ends (RACE). The sGnRH and cGnRH-II precursor cDNAs consisted of 439 and 628 bp, and included open reading frames of 282 and 255 bp respectively. The structures of the encoded peptides were the same as GnRHs previously identified in other vertebrates. The sGnRH and cGnRH-II precursor cDNAs, including the non-coding regions, had 88.6 and 79.9% identity respectively, to those identified in goldfish (Carassius auratus). However, significant similarity was not observed between the non-coding regions of the GnRH cDNAs of Cyprinidae and other fish. The presumed third exon, encoding partial sGnRH associated peptide (GAP) of roach, demonstrated significant nucleotide and amino acid similarity with the appropriate regions in the goldfish, but not with other species, and this may indicate functional differences of GAP between different families of fish. cGnRH-II precursor cDNAs from roach had relatively high nucleotide similarity across this GnRH variant. Cladistic analysis classified the sGnRH and cGnRH-II precursor cDNAs into three and two groups respectively. However, the divergence between nucleotide sequences within the sGnRH variant was greater than those encoding the cGnRH-II precursors. Consistent with the consensus developed from previous studies, Northern blot analysis demonstrated that expression of sGnRH and cGnRH-II was restricted to the olfactory bulbs and midbrain of roach respectively. This work forms the basis for further study on the mechanisms by which the tapeworm, Ligula intestinalis, interacts with the pituitary-gonadal axis of its fish host.

  18. Dietary taurine supplementation ameliorates the lethal effect of phenanthrene but not the bioaccumulation in a marine teleost, red sea bream, Pagrus major.

    Science.gov (United States)

    Hano, Takeshi; Ito, Mana; Ito, Katsutoshi; Kono, Kumiko; Ohkubo, Nobuyuki

    2017-03-01

    The present study was performed to evaluate the effect of dietary taurine on the hepatic metabolic profiles of red sea bream (Pagrus major) and on phenanthrene (a polyaromatic hydrocarbon) toxicity and bioaccumulation. The fish were fed a diet supplemented with 0% (TAU0%), 0.5% (TAU0.5%), or 5% (TAU5%) taurine for 40-55d and subjected to phenanthrene acute toxicity and bioaccumulation tests. Taurine deficiency in feed severely affected the hepatic metabolic profiles of fish, which indicated a complementary physiological response to taurine deficiency. For the acute toxicity test, fish were fed the test diets for 55d and were then exposed to 0-893µg/L phenanthrene for 96h. Tolerance to phenanthrene was significantly improved by 0.5% of taurine inclusion in feed relative to TAU0%, but not by 5.0% inclusion. Reduced glutathione in the liver, which acts as an oxygen-free radical scavenger, was associated with a reduction in the toxicity of phenanthrene. For the bioaccumulation test, fish were fed the test diets for 40d and were thereafter chronically exposed to 20µg/L phenanthrene for 13d followed by depuration for 3d. The activity of hepatic biomarker, ethoxyresorufin-O-deethylase, was increased by phenanthrene exposure in the taurine inclusion groups. However, phenanthrene concentrations in the liver and muscle of fish fed TAU5.0% tended to be higher than those of fish fed TAU0% and TAU0.5% during the exposure period. These results indicate that 0.5% of taurine inclusion in feed plays an important role in the alleviation of phenanthrene toxicity but not bioaccumulation. Furthermore, larger amount of taurine inclusion (TAU5%) did not show marked beneficial effects against phenanthrene exposure. This study provides insight about a major concern of environmental contaminants into aquatic environment and can be effectively used for improvement of aquaculture. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. The evolution of the vertebrate cerebellum: absence of a proliferative external granule layer in a non-teleost ray-finned fish

    OpenAIRE

    Butts, Thomas; Modrell, Melinda Sue; Baker, Clare Victoria; Wingate, Richard JT

    2014-01-01

    The cerebellum represents one of the most morphologically variable structures in the vertebrate brain. To shed light on its evolutionary history, we have examined the molecular anatomy and proliferation of the developing cerebellum of the North American paddlefish, Polyodon spathula. Absence of an external proliferative cerebellar layer and the restriction of Atonal1 expression to the rhombic lip and valvular primordium demonstrate that transit amplification in a cerebellar external germinal ...

  20. Evolution of Recognition of Ligands from Gram-Positive Bacteria: Similarities and Differences in the TLR2-Mediated Response between Mammalian Vertebrates and Teleost Fish

    NARCIS (Netherlands)

    Ribeiro, Carla M. S.; Hermsen, Trudi; Taverne-Thiele, Anja J.; Savelkoul, Huub F. J.; Wiegertjes, Geert F.

    2010-01-01

    We investigated the role of the TLR2 receptor in the recognition of ligands from Gram-positive bacteria in fish. Comparative sequence analysis showed a highly conserved Toll/IL-1 receptor domain. Although the leucine-rich repeat domain was less conserved, the position of the critical peptidoglycan

  1. Transition in organ function during the evolution of air-breathing; insights from Arapaima gigas, an obligate air-breathing teleost from the Amazon.

    Science.gov (United States)

    Brauner, C J; Matey, V; Wilson, J M; Bernier, N J; Val, A L

    2004-04-01

    The transition from aquatic to aerial respiration is associated with dramatic physiological changes in relation to gas exchange, ion regulation, acid-base balance and nitrogenous waste excretion. Arapaima gigas is one of the most obligate extant air-breathing fishes, representing a remarkable model system to investigate (1) how the transition from aquatic to aerial respiration affects gill design and (2) the relocation of physiological processes from the gills to the kidney during the evolution of air-breathing. Arapaima gigas undergoes a transition from water- to air-breathing during development, resulting in striking changes in gill morphology. In small fish (10 g), the gills are qualitatively similar in appearance to another closely related water-breathing fish (Osteoglossum bicirrhosum); however, as fish grow (100-1000 g), the inter-lamellar spaces become filled with cells, including mitochondria-rich (MR) cells, leaving only column-shaped filaments. At this stage, there is a high density of MR cells and strong immunolocalization of Na(+)/K(+)-ATPase along the outer cell layer of the gill filament. Despite the greatly reduced overall gill surface area, which is typical of obligate air-breathing fish, the gills may remain an important site for ionoregulation and acid-base regulation. The kidney is greatly enlarged in A. gigas relative to that in O. bicirrhosum and may comprise a significant pathway for nitrogenous waste excretion. Quantification of the physiological role of the gill and the kidney in A. gigas during development and in adults will yield important insights into developmental physiology and the evolution of air-breathing.

  2. A comparative assessment of the adrenotoxic effects of cadmium in two teleost species, rainbow trout, Oncorhynchus mykiss, and yellow perch, Perca flavescens

    International Nuclear Information System (INIS)

    Lacroix, Alexandra; Hontela, Alice

    2004-01-01

    Rainbow trout (Oncorhynchus mykiss) and yellow perch (Perca flavescens) have a different sensitivity to cadmium (Cd) in vivo (trout O.mykiss =175.6>LC50/EC50 P.flavescens =37.7). Adrenocortical cells of trout were more sensitive than those of perch and Cd had a higher endocrine-disrupting potential and specificity in trout than in perch. However, in both species, Cd had the same effect on ACTH, dbcAMP and pregnenolone-stimulated cortisol secretion, with pregnenolone maintaining cortisol secretion until cell viability was impaired. These results confirm that for both species, Cd interferes in the signalling pathway of cortisol synthesis in a step prior to the pregnenolone formation. Data provided by the present study revealed important differences in vulnerability of adrenal steroidogenesis between rainbow trout and yellow perch

  3. Specific cerebral heat shock proteins and histamine receptor cross-talking mechanisms promote distinct lead-dependent neurotoxic responses in teleosts

    International Nuclear Information System (INIS)

    Giusi, Giuseppina; Alo, Raffaella; Crudo, Michele; Facciolo, Rosa Maria; Canonaco, Marcello

    2008-01-01

    Recent interests are beginning to be directed towards toxic neurobiological dysfunctions caused by lead (Pb) in aquatic vertebrates. In the present work, treatment with a maximum acceptable toxic concentration of this heavy metal was responsible for highly significant (p 2 R) antagonist cimetidine (Cim), as shown by the very robust (p 3 R) thioperamide (Thio), instead, blocked Pb-dependent up-regulatory trends of both chaperones in mostly hypothalamic areas. Moreover, intense neuronal damages of the above brain regions coincided with altered expressions of HSP70 and HSP90 when treated only with Cim. Overall these first results show that distinct H n R are able to exert a net neuroprotective role arising from their interaction with chaperones in fish exposed to Pb-dependent stressful conditions making this a potentially key interaction especially for T. pavo, aquatic species which plays an important ecological role towards the survival of other commercially vital fishes

  4. The Asian arowana (Scleropages formosus) genome provides new insights into the evolution of an early lineage of teleosts

    DEFF Research Database (Denmark)

    Bian, Chao; Hu, Yinchang; Ravi, Vydianathan

    2016-01-01

    five Hox clusters. Differential gene expression among three varieties provides insights into the genetic basis of colour variation. A potential heterogametic sex chromosome is identified in the female arowana karyotype, suggesting that the sex is determined by a ZW/ZZ sex chromosomal system. The high...

  5. Influence of the mode of uptake on the elimination of cobalt 60 by a phanerogam, a mollusc, a crustacean and a freshwater teleost

    International Nuclear Information System (INIS)

    Amiard-Triquet, C.

    1979-01-01

    60 Co enters the environment with radioactive wastes from nuclear power reactors and fuel reprocessing plants as well as a component of fallout from nuclear tests. A study of 60 Co in freshwater organisms has been carried out in order to compare the influence of different modes of uptake (immersion in contaminated water, ingestion of radioactive food, contamination by both food and water) upon the subsequent elimination. The loss of 60 Co by Canadian pondweed Elodea canadensis is monophasic. For animal species, this phenomenon is biphasic, independently of the mode of uptake. On the other hand, the biological half-life changes in relation to the vector of contamination. The same result is observed for the relative importance of the different compartments. This is easily explained because the mode of uptake determines the distribution of 60 Co in the organisms. The turnover of 60 Co in the organisms is slow and the physical half-life of this radionuclide is relatively important (Tsub(p) = 5.27 years). Thus, the possible consequences of the release of this pollutant on freshwater life must not be neglected. (author)

  6. The development of hyaline-cell cartilage in the head of the black molly, Poecilia sphenops. Evidence for secondary cartilage in a teleost.

    OpenAIRE

    Benjamin, M

    1989-01-01

    The development of hyaline-cell cartilage attached to membrane (dentary, maxilla, nasal, lacrimal and cleithrum) and cartilage (basioccipital) bones has been studied in the viviparous black molly, Poecilia sphenops. Intramembranous ossification commences before the first appearance of hyaline cells. As hyaline-cell cartilage is densely cellular and as that attached to the dentary, maxilla and cleithrum develops from the periosteum of these membrane bones, it must be regarded as secondary cart...

  7. The development of hyaline-cell cartilage in the head of the black molly, Poecilia sphenops. Evidence for secondary cartilage in a teleost.

    Science.gov (United States)

    Benjamin, M

    1989-01-01

    The development of hyaline-cell cartilage attached to membrane (dentary, maxilla, nasal, lacrimal and cleithrum) and cartilage (basioccipital) bones has been studied in the viviparous black molly, Poecilia sphenops. Intramembranous ossification commences before the first appearance of hyaline cells. As hyaline-cell cartilage is densely cellular and as that attached to the dentary, maxilla and cleithrum develops from the periosteum of these membrane bones, it must be regarded as secondary cartilage according to current concepts. It is also argued that the hyaline-cell cartilage attached to the perichondral bone of the basioccipital (a cartilage bone), could also be viewed as secondary. The status of the cartilage on the nasal and lacrimal bones is less clear, for it develops, at least in part, from mucochondroid (mucous connective) tissue. This is the first definitive report of secondary cartilage in any lower vertebrate. The tissue is therefore not restricted to birds and mammals as hitherto believed, and a multipotential periosteum must have arisen early in vertebrate evolution. Images Fig. 1 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 PMID:2481666

  8. The effect of wildfire on population dynamics for two native small mammal species in a coastal heathland in Queensland, Australia

    Science.gov (United States)

    Liedloff, Adam C.; Wilson, John C.; Engeman, Richard M.

    2018-04-01

    The influences of wildfire through population dynamics and life history for two species of small mammals in a south-east Queensland heathland on Bribie Island are presented. Trapping results provided information on breeding, immigration and movement of Melomys burtoni (Grassland melomys) and Rattus lutreolus (Swamp rat). We first investigated and optimized the design of trapping methodology for producing mark-recapture population estimates to compare two adjacent populations, one of which was subjected to an extensive wildfire during the two year study. We consider how well rodents survive wildfire and whether the immediate impacts of fire or altered habitat have the greatest impact on each species. We found the R. lutreolus population was far more influenced by the fire than the M. burtoni population both immediately after the fire and over 18 months of vegetation recovery.

  9. Võimsate isiksuste paraad New Yorgis / Tanel Veenre

    Index Scriptorium Estoniae

    Veenre, Tanel, 1977-

    2010-01-01

    Marina Abramobići (Serbia) näitus "The Artist is Present" ja William Kentridge'i (Lõuna-Aafrika) söejoonistuste ja animatsioonide näitus "Five themes" MoMa-s (Museum of Modern Art). Tim Burtoni (USA) fotolavastuste, joonistuste ja installatsioonide näitus ning Agnolo Bronzino (1503-1572, Itaalia) joonistuste väljapanek Metropolitan Museumis

  10. Duplicated leptin receptors in two species of eel bring new insights into the evolution of the leptin system in vertebrates

    DEFF Research Database (Denmark)

    Morini, M.; Pasquier, J.; van den Thillart, G.

    2015-01-01

    Since its discovery in mammals as a key-hormone in reproduction and metabolism, leptin has been identified in an increasing number of tetrapods and teleosts. Tetrapods possess only one leptin gene, while most teleosts possess two leptin genes, as a result of the teleost third whole genome duplica...

  11. Ecomorphology and food habits of teleost fishes Trachinotus carolinus (Teleostei: Carangidae and Menticirrhus littoralis (Teleostei: Sciaenidae, inhabiting the surf zone off Niterói, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Luana Prestrelo Palmeira

    2010-01-01

    Full Text Available The ecomorphology and food habits of juvenile Trachinotus carolinus and Menticirrhus littoralis caught in the surf zone of sandy beaches in Niterói, RJ, were investigated between July 2006 and May 2007. These fish species differ morphologically, but present similarities in their diet composition suggest some slight overlapping in their diet. The importance of food items was assessed using Kawakami and Vazzoler's feeding index. Morphometric variables were recorded to correlate with the diet composition of the different size classes for each species. A total of 210 fishes (Trachinotus carolinus - 122, Menticirrhus littoralis - 88, ranging between 24.2 mm and 112 mm total length, were analyzed, but the stomachs of only 84.8% of them contained food. Trachinotus carolinus presented mysids, Polychaetes and Emerita spp. as the predominant items in their diet. Formicidae and Isopoda were the most important items for class I individuals, whereas mysids and Emerita spp. were important for classes II and III. Class I individuals also showed smaller sized prey (amphipods and isopods and clupeid fish larvae in their diet. Emerita spp. dominated the food items of Menticirrhus littoralis regardless of the size class. Polychaetes, the second most important item was better represented in class sizes II and III. The main morphometric variable correlated with such differences included mouth position and diameter of the eye.A ecomorfologia e os hábitos alimentares de juvenis de Trachinotus carolinus e Menticirrhus littoralis capturados na zona de arrebentação de praias arenosas em Niterói, RJ, foram investigados entre julho de 2006 e Maio de 2007. Ambas as espécies diferem morfologicamente, mas apresentam semelhanças em sua dieta, sugerindo uma possível sobreposição alimentar. A importância dos itens alimentares foi avaliada utilizando o índice alimentar de Kawakami e Vazzoler. Variáveis morfométricas foram correlacionadas à dieta observada para diferentes classes de tamanho, para cada espécie. Um total de 210 peixes (Trachinotus carolinus - 122, Menticirrhus littoralis - 88, variando entre 24.2 mm e 112 mm de comprimento total, foram analisados, mas apenas 84.8% continham alimento. Trachinotus carolinus apresentou mysidáceos, poliquetas e Emerita spp. como os itens predominantes na dieta. Formicidae e Isopoda foram os itens mais importantes para a classe I de tamanho dos indivíduos, enquanto que mysidáceos e Emerita spp. foram importantes para as classes II e III. Indivíduos da classe I também apresentaram itens de menor tamanho (anfípodos e isópodos bem como larvas de peixes clupeídeos na dieta. Emerita spp. dominou a alimentação de Menticirrhus littoralis, independentemente da classe de tamanho. Poliquetas, o segundo item mais importante, foi mais bem representado na classe II e III de tamanho dos indivíduos. As principais variáveis morfométricas correlacionadas com essas diferenças incluíram a posição da boca e o diâmetro do olho.

  12. The Effect of Prolactin on the Number of Membrane-Associated Particles in Kidney Cells of the Euryhaline Teleost Gasterosteus aculeatus during Transfer from Seawater to Freshwater : A Freeze-Etch Study

    NARCIS (Netherlands)

    Wendelaar Bonga, S.E.; Veenhuis, M.

    1974-01-01

    The membranes of kidney cells of 3-spined sticklebacks were examined in freeze-etch replicas. The numbers of particles adhering to surfaces and fracture faces of the outer cell membranes and the membranes of the basal labyrinth were determined. The latter membranes probably are the main location of

  13. First comparative characterization of three distinct ferritin subunits from a teleost: Evidence for immune-responsive mRNA expression and iron depriving activity of seahorse (Hippocampus abdominalis) ferritins.

    Science.gov (United States)

    Oh, Minyoung; Umasuthan, Navaneethaiyer; Elvitigala, Don Anushka Sandaruwan; Wan, Qiang; Jo, Eunyoung; Ko, Jiyeon; Noh, Gyeong Eon; Shin, Sangok; Rho, Sum; Lee, Jehee

    2016-02-01

    Ferritins play an indispensable role in iron homeostasis through their iron-withholding function in living beings. In the current study, cDNA sequences of three distinct ferritin subunits, including a ferritin H, a ferritin M, and a ferritin L, were identified from big belly seahorse, Hippocampus abdominalis, and molecularly characterized. Complete coding sequences (CDS) of seahorse ferritin H (HaFerH), ferritin M (HaFerM), and ferritin L (HaFerL) subunits were comprised of 531, 528, and 522 base pairs (bp), respectively, which encode polypeptides of 177, 176, and 174 amino acids, respectively, with molecular masses of ∼20-21 kDa. Our in silico analyses demonstrate that these three ferritin subunits exhibit the typical characteristics of ferritin superfamily members including iron regulatory elements, domain signatures, and reactive centers. The coding sequences of HaFerH, M, and L were cloned and the corresponding proteins were overexpressed in a bacterial system. Recombinantly expressed HaFer proteins demonstrated detectable in vivo iron sequestrating (ferroxidase) activity, consistent with their putative iron binding capability. Quantification of the basal expression of these three HaFer sequences in selected tissues demonstrated a gene-specific ubiquitous spatial distribution pattern, with abundance of mRNA in HaFerM in the liver and predominant expression of HaFerH and HaFerL in blood. Interestingly, the basal expression of all three ferritin genes was found to be significantly modulated against pathogenic stress mounted by lipopolysaccharides (LPS), poly I:C, Streptococcus iniae, and Edwardsiella tarda. Collectively, our findings suggest that the three HaFer subunits may be involved in iron (II) homeostasis in big belly seahorse and that they are important in its host defense mechanisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  15. Demography and genome divergence of lake and stream populations of an East African cichlid fish.

    Science.gov (United States)

    Egger, Bernd; Roesti, Marius; Böhne, Astrid; Roth, Olivia; Salzburger, Walter

    2017-10-01

    Disentangling the processes and mechanisms underlying adaptive diversification is facilitated by the comparative study of replicate population pairs that have diverged along a similar environmental gradient. Such a setting is realized in a cichlid fish from southern Lake Tanganyika, Astatotilapia burtoni, which occurs within the lake proper as well as in various affluent rivers. Previously, we demonstrated that independent lake and stream populations show similar adaptations to the two habitat regimes. However, little is known about the evolutionary and demographic history of the A. burtoni populations in question and the patterns of genome divergence among them. Here, we apply restriction site-associated DNA sequencing (RADseq) to examine the evolutionary history, the population structure and genomic differentiation of lake and stream populations in A. burtoni. A phylogenetic reconstruction based on genome-wide molecular data largely resolved the evolutionary relationships among populations, allowing us to re-evaluate the independence of replicate lake-stream population clusters. Further, we detected a strong pattern of isolation by distance, with baseline genomic divergence increasing with geographic distance and decreasing with the level of gene flow between lake and stream populations. Genome divergence patterns were heterogeneous and inconsistent among lake-stream population clusters, which is explained by differences in divergence times, levels of gene flow and local selection regimes. In line with the latter, we only detected consistent outlier loci when the most divergent lake-stream population pair was excluded. Several of the thus identified candidate genes have inferred functions in immune and neuronal systems and show differences in gene expression between lake and stream populations. © 2017 John Wiley & Sons Ltd.

  16. Social Crowding during Development Causes Changes in GnRH1 DNA Methylation.

    Science.gov (United States)

    Alvarado, Sebastian G; Lenkov, Kapa; Williams, Blake; Fernald, Russell D

    2015-01-01

    Gestational and developmental cues have important consequences for long-term health, behavior and adaptation to the environment. In addition, social stressors cause plastic molecular changes in the brain that underlie unique behavioral phenotypes that also modulate fitness. In the adult African cichlid, Astatotilapia burtoni, growth and social status of males are both directly regulated by social interactions in a dynamic social environment, which causes a suite of plastic changes in circuits, cells and gene transcription in the brain. We hypothesized that a possible mechanism underlying some molecular changes might be DNA methylation, a reversible modification made to cytosine nucleotides that is known to regulate gene function. Here we asked whether changes in DNA methylation of the GnRH1 gene, the central regulator of the reproductive axis, were altered during development of A. burtoni. We measured changes in methylation state of the GnRH1 gene during normal development and following the gestational and developmental stress of social crowding. We found differential DNA methylation within developing juveniles between 14-, 28- and 42-day-old. Following gestational crowding of mouth brooding mothers, we saw differential methylation and transcription of GnRH1 in their offspring. Taken together, our data provides evidence for social control of GnRH1 developmental responses to gestational cues through DNA methylation.

  17. Anatomía visceral de Feylinia grandisquamis (Squamata: Scincidae. Comparaciones con otros escamados de patrón corporal semejante

    Directory of Open Access Journals (Sweden)

    Díaz Gómez, Juan Manuel

    2003-07-01

    Full Text Available Feylinia grandisquamis es un síncido africano caracterizado por contar con el cuerpo alargado y las extremidades ausentes. En el presente trabajo se describe en detalle la anatomía de las vísceras de Feylinia grandisquamis, y algunos aspectos de su variación intraespecífica. Los resultados se comparan con otro género de Scincidae (Anomalopus y representantes de grandes grupos de escamados que exhiben patrones corporales semejantes (Lialis burtonis, Amphisbaena darwinii, Boa constrictor, Ophiodes striatus, Anguis fragilis. Los objetivos de este trabajo fueron: a determinar la morfología de las vísceras de Feylinia; b los aspectos de su variación intraespecífica; c discutir convergencias y paralelismos con Saurios, Anfisbénidos y Ofidios. Feylinia grandisquamis is an African Scincid characterized for a snakeshaped body and total absence of limbs. In this work the visceral anatomy of Feylinia grandisquamis is described, as well as aspects of its intraspecific variation. The results are compared with another scincid (Anomalopus and representatives of other Squamate groups with similar body plans (Lialis burtonis, Amphisbaena darwinii, Boa constrictor, Ophiodes striatus, Anguis fragilis. The objectives were: a To determine the visceral anatomy of Feylinia; b The aspects of its intraespecific variation; and c Discuss convergences and parallelisms with possible occurrence in Lizards, Amphisbaenids and Ophidia.

  18. Branchial expression and localization of the insulin-like growth factor 1 (IGF-1) receptor and changes in plasma IGF-1 and IGF-1 binding protein in striped bass during salinity acclimation

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Madsen, Steffen; Borski, Russell

    2006-01-01

    In euryhaline teleosts the insulin-like growth factor 1 (IGF-1)/growth hormone axis is known to affect salinity tolerance and gill Na,K-ATPase activity. However, virtually nothing is known on expression and cellular localization of the IGF-1 receptor (IGF-1R) in the teleost gill during salinity a...

  19. Long-term catch and effort trends in Eastern Cape Angling Week ...

    African Journals Online (AJOL)

    The most commonly caught species were Argyrosomus japonicus (20.3%), Mustelus mustelus/Triakis megalopterus (13.0%) and Carcharias taurus (11.8%). Mean CPUE for all fish caught, teleosts and elasmobranchs, as well as the top four teleost and elasmobranch species, increased over the course of the study period, ...

  20. The behaviour and brain function of the Cichlid fish ...

    African Journals Online (AJOL)

    ... the teleost forebrain houses a primitive limbic system the main functions of which would be general arousal and the selection of appropriate responses to the incoming external and endogenous (motivational) stimuli. Keywords: Brain Function, Teleost, telencephalon, Cichlid fish behaviour, limbic system, hippocampus ...

  1. Hematologia de teleósteos brasileiros com infecção parasitária. I. Variáveis do Leporinus macrocephalus Garavelo e Britski, 1988 (Anostomidae e Piaractus mesopotamicus Holmberg, 1887 (Characidae Haematology of parasitized Brazilian teleost fishes. I. Parameters of Leporinus macrocephalus Garavelo and Britski, 1988 (Anostomidae and Piaractus mesopotamicus Holmberg, 1887 (Characidae

    Directory of Open Access Journals (Sweden)

    Dilermando Perecin

    1999-07-01

    Full Text Available Espécimes de Leporinus macrocephalus (piauçu e de Piaractus mesopotamicus (pacu foram colhidos em piscicultura do município de Franca (SP para avaliação dos efeitos da infecção parasitária sobre a taxa de hemoglobina e de hematócrito, a concentração de hemoglobina corpuscular média (CHCM, o fator relativo de condição (Kn e a distribuição percentual de células sangüíneas de defesa orgânica (leucócitos e trombócitos. Ambas as espécies apresentavam-se parasitadas por monogenea ou por monogenea e outros parasitas: monogenea e Trichodina sp; monogenea e Lernaea cyprinacea; monogenea e Piscinoodinium pillulare; monogenea e Ichthyophthirius multifiliis; monogenea, I. multifiliis e Trichodina sp. Os resultados demonstraram que os parâmetros estudados em L. macrocephalus e em P. mesopotamicus não foram significativamente (p > 0,05 alterados pelo parasitismo. A análise de regressão linear mostrou correlação negativa (p > 0,05 entre linfócitos e trombócitos em L. macrocephalus e correlação positiva (p > 0,01 da taxa de hemoglobina com o peso e com o comprimento total em P. mesopotamicus.Specimens of cultivated Leporinus macrocephalus (piauçu and Piaractus mesopotamicus (pacu were collected in a fishfarm at Franca, SP. Effects of parasite infection upon hemoglobin, hematocrit, mean corpuscular hemoglobin concentration (MCHC, condition factor (Kn and differential count of defense cells (leucocyte and thrombocyte were evaluated. Both fish species were parasitized by monogenean; monogenean and Trichodina sp; monogenean and Lernaea cyprinacea; monogenean and Piscinoodinium pillulare; monogenean and Ichthyophthirius miltifiliis; monogenean, I. multifiliis and Trichodina sp. Parasitism did not influence (p > 0.05 the studied haematological characteristics in L. macrocephalus and P. mesopotamicus. Linnear regression showed negative correlation (p > 0.05 between lymphocytes and thrombocytes in L. macrocephalus and positive correlation (p > 0.01 of the hemoglobin rate with fish weight and fish length in P. mesopotamicus.

  2. 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)

    OpenAIRE

    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...

  3. Dietary variations within a family of ambush predators (Platycephalidae) occupying different habitats and environments in the same geographical region.

    Science.gov (United States)

    Coulson, P G; Platell, M E; Clarke, K R; Potter, I C

    2015-03-01

    This study has determined the extents and basis for variations in the composition of the prey ingested by the abundant species of a family highly adapted for ambush predation, i.e. Platycephalidae, in a region (south-western Australia) where that family is found in different habitats and environments. Dietary data were thus collected for Leviprora inops and Platycephalus laevigatus from seagrass in marine embayments and for Platycephalus westraliae from over sand in an estuary. These were then collated with those recorded previously for Platycephalus speculator from over sand and in seagrass in an estuary and for Platycephalus longispinis from over sand in coastal marine waters. While crustaceans and teleosts together dominated the diet of all five species, their percentage volumetric dietary contributions varied greatly, with those of crustaceans ranging from 7% for L. inops to 65% for P. speculator and those of teleosts ranging from 29% for P. longispinis to 91% for L. inops. For analyses, the data were separated into two sets. The first comprised the 17 dietary categories of invertebrates and all identified and unidentified teleosts collectively, while the second consisted of the 23 identified teleost families, both of which were subjected to permutational analysis of variance (PERMANOVA), analysis of similarities (ANOSIM) and a new (two-way) version of the RELATE procedure. The diets of three species changed seasonally, when using invertebrate dietary categories and teleosts collectively, but with only one species, when employing identified teleost families, probably reflecting a greater tendency for invertebrate than teleost prey abundance to change during the year. On the basis of dietary data for invertebrate taxa + teleosts collectively, the diets of three of the five species changed serially with body size, with a fourth species feeding, throughout life, predominantly on the carid Palaemonetes australis. Based on identified teleost families, the diets of

  4. The relationship between temperature and standard rate of ...

    African Journals Online (AJOL)

    teleost) fishes, while largely unknown, is essential to an understanding of the effects of temperature on fish energetics. This study quantifies the effect of temperature on the standard rate of metabolism in the African lungfish, Protopterus aethiopicus.

  5. Polymorphism in NPY and IGF-I genes associate with reproductive ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... effects of NPY and IGF-I genes on reproductive traits of chickens. Key words: ... flavor and good egg quality are accorded with Chinese consumers' taste. ... Numerous studies in mammals and more recently in teleost fish.

  6. THE BEHAVIOUR AND BRAIN FUNCTION OF THE CICHLID FISH ...

    African Journals Online (AJOL)

    male and female conspecifics on a visual basis. ... Brain Function, Teleost, telencephalon, Cichlid fish behaviour, limbic system, hippocampus. ...... The effects of forebrain ablations on the behaviour of H. philander cannot be satisfactorily.

  7. Modulation of Aromatase Activity as a Mode of Action for Endocrine Disrupting Chemicals in a Marine Fish

    Science.gov (United States)

    The steroidogenic enzyme aromatase catalyzes the conversion of androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) and therefore plays a central role in reproduction. In contrast to most vertebrates, teleost fish have two distinct forms of aromatase....

  8. 199-IJBCS-Article-Prof A K Srivastav

    African Journals Online (AJOL)

    RHUMSIKI

    -water integumentary changes in the urodeles. However, fish prolactin does not .... haemopoietic system in a freshwater teleost Labeo rohita following chronic chlordane exposure. I. Alteration in certain hematological parameters. Bull. Environ ...

  9. African Journal of Aquatic Science - Vol 33, No 1 (2008)

    African Journals Online (AJOL)

    The impact of invasive fish and invasive riparian plants on the invertebrate ... by four small teleost fish species from the Igoda Estuary, Eastern Cape, South Africa ... in the Mzingwane River, Zimbabwe · EMAIL FULL TEXT EMAIL FULL TEXT

  10. United States of America. Report 7 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Townsley, S.J.

    1967-01-01

    Present research programme (long-term): Interrelationship of environmental salt concentration and concentration of dissolved radionuclides to the rate of accumulation of these nuclides by euryhaline teleosts. Objectives of this research are designed toward the definition of a function that will adequately described the rate of accumulation of selected radionuclides by euryhaline teleosts from littoral or estuarine environments. Concurrent studies are being made to determine the maximum concentration accumulated by these fish under conditions of chronic exposure to selected concentrations in the medium

  11. The role of adrenaline as a modulator of cardiac performance in three Notothenioid fishes

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Bushnell, P.; Tirsgaard, Bjørn

    2008-01-01

    The present work was performed to test the hypothesis that Antarctic teleosts rely mostly on cholinergic inhibition to modulate cardiac performance. Isometric muscle preparations were used to examine the inotropic and chronotropic properties of the ventricle and atrium in three Antarctic teleosts...... adrenaline appear to enhance force of contraction for atrial muscle. The study finds that adrenaline modulates ventricular inotropic properties in all species. For Notothenia coriiceps the regulation of power production purely by adrenergic stimulation appeared most beneficial, while for N. microlepidota...

  12. Developmental finite element analysis of cichlid pharyngeal jaws: Quantifying the generation of a key innovation

    Science.gov (United States)

    Müller, Gerd B.

    2018-01-01

    Advances in imaging and modeling facilitate the calculation of biomechanical forces in biological specimens. These factors play a significant role during ontogenetic development of cichlid pharyngeal jaws, a key innovation responsible for one of the most prolific species diversifications in recent times. MicroCT imaging of radiopaque-stained vertebrate embryos were used to accurately capture the spatial relationships of the pharyngeal jaw apparatus in two cichlid species (Haplochromis elegans and Amatitlania nigrofasciata) for the purpose of creating a time series of developmental stages using finite element models, which can be used to assess the effects of biomechanical forces present in a system at multiple points of its ontogeny. Changes in muscle vector orientations, bite forces, force on the neurocranium where cartilage originates, and stress on upper pharyngeal jaws are analyzed in a comparative context. In addition, microCT scanning revealed the presence of previously unreported cement glands in A. nigrofasciata. The data obtained provide an underrepresented dimension of information on physical forces present in developmental processes and assist in interpreting the role of developmental dynamics in evolution. PMID:29320528

  13. Developmental finite element analysis of cichlid pharyngeal jaws: Quantifying the generation of a key innovation.

    Directory of Open Access Journals (Sweden)

    Tim Peterson

    Full Text Available Advances in imaging and modeling facilitate the calculation of biomechanical forces in biological specimens. These factors play a significant role during ontogenetic development of cichlid pharyngeal jaws, a key innovation responsible for one of the most prolific species diversifications in recent times. MicroCT imaging of radiopaque-stained vertebrate embryos were used to accurately capture the spatial relationships of the pharyngeal jaw apparatus in two cichlid species (Haplochromis elegans and Amatitlania nigrofasciata for the purpose of creating a time series of developmental stages using finite element models, which can be used to assess the effects of biomechanical forces present in a system at multiple points of its ontogeny. Changes in muscle vector orientations, bite forces, force on the neurocranium where cartilage originates, and stress on upper pharyngeal jaws are analyzed in a comparative context. In addition, microCT scanning revealed the presence of previously unreported cement glands in A. nigrofasciata. The data obtained provide an underrepresented dimension of information on physical forces present in developmental processes and assist in interpreting the role of developmental dynamics in evolution.

  14. Observations préliminaires sur la répartition et les fluctuations de l'ichtyomasse exploitable dans les différentes zones écologiques du lac Ihema (bassin moyen de l'Akagera, Rwanda

    Directory of Open Access Journals (Sweden)

    Mughanda, M.

    1988-01-01

    Full Text Available Preliminary considerations on distribution and changes in fishable ichtyomass in the ecological areas of lake Ihema (Akagera middle, Foodplain, Rwanda. Since 1981, commercial fishing is accomplished in lake Ihema with gillnets of 50 mm meshes and a mean of 175 tons of fish was caught per year during the first three years. Simultaneously, experimental fishing was introduced since 1982, for which ten gillnets of different meshes are used. Fishes of the two general Tilapia and Clarias are captured in commercial fishing, but in experimental one, about ten taxons of fish are caught. For this paper, we examined statistics obtained from experimental catches during 1982 and 1983. Apart from Tilapia and Clarias, small Cichlidae of Haplochromis group, two species of Mormyridae and Synodontis spp represent a potential which may be exploited with other kinds of gear. Concerning productiveness of fishing areas in lake Ihema, littoral zones (= inshore are more rich than pelagic (= offshore ones and the northern sector in which Akagera river enters the lake is the most productive. Species of fish are differently represented in ecological zones, following the kind of their food (planctonophagous, detritivorous or carnivorous and the places they can reproduce. Catches fluctuate monthly and annually probably because of natural changes in fish stock according to fluctuations of climatic conditions, but also because of increasing intensity of commercial fishing. For Tilapia, reduction in the quantity captured may also be due to introgressive hybridization and competition between T. macrochir, T. nilotica and their hybrids.

  15. Revisiting available knowledge on teleostean thyroid hormone receptors.

    Science.gov (United States)

    Lazcano, Iván; Orozco, Aurea

    2018-03-21

    Teleosts are the most numerous class of living vertebrates. They exhibit great diversity in terms of morphology, developmental strategies, ecology and adaptation. In spite of this diversity, teleosts conserve similarities at molecular, cellular and endocrine levels. In the context of thyroidal systems, and as in the rest of vertebrates, thyroid hormones in fish regulate development, growth and metabolism by actively entering the nucleus and interacting with thyroid hormone receptors, the final sensors of this endocrine signal, to regulate gene expression. In general terms, vertebrates express the functional thyroid hormone receptors alpha and beta, encoded by two distinct genes (thra and thrb, respectively). However, different species of teleosts express thyroid hormone receptor isoforms with particular structural characteristics that confer singular functional traits to these receptors. For example, teleosts contain two thra genes and in some species also two thrb; some of the expressed isoforms can bind alternative ligands. Also, some identified isoforms contain deletions or large insertions that have not been described in other vertebrates and that have not yet been functionally characterized. As in amphibians, the regulation of some of these teleost isoforms coincides with the climax of metamorphosis and/or life transitions during development and growth. In this review, we aimed to gain further insights into thyroid signaling from a comparative perspective by proposing a systematic nomenclature for teleost thyroid hormone receptor isoforms and summarize their particular functional features when the information was available. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Fatty acid-binding protein genes of the ancient, air-breathing, ray-finned fish, spotted gar (Lepisosteus oculatus).

    Science.gov (United States)

    Venkatachalam, Ananda B; Fontenot, Quenton; Farrara, Allyse; Wright, Jonathan M

    2018-03-01

    With the advent of high-throughput DNA sequencing technology, the genomic sequence of many disparate species has led to the relatively new discipline of genomics, the study of genome structure, function and evolution. Much work has been focused on the role of whole genome duplications (WGD) in the architecture of extant vertebrate genomes, particularly those of teleost fishes which underwent a WGD early in the teleost radiation >230 million years ago (mya). Our past work has focused on the fate of duplicated copies of a multigene family coding for the intracellular lipid-binding protein (iLBP) genes in the teleost fishes. To define the evolutionary processes that determined the fate of duplicated genes and generated the structure of extant fish genomes, however, requires comparative genomic analysis with a fish lineage that diverged before the teleost WGD, such as the spotted gar (Lepisosteus oculatus), an ancient, air-breathing, ray-finned fish. Here, we describe the genomic organization, chromosomal location and tissue-specific expression of a subfamily of the iLBP genes that code for fatty acid-binding proteins (Fabps) in spotted gar. Based on this work, we have defined the minimum suite of fabp genes prior to their duplication in the teleost lineages ~230-400 mya. Spotted gar, therefore, serves as an appropriate outgroup, or ancestral/ancient fish, that did not undergo the teleost-specific WGD. As such, analyses of the spatio-temporal regulation of spotted gar genes provides a foundation to determine whether the duplicated fabp genes have been retained in teleost genomes owing to either sub- or neofunctionalization. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Resolution of ray-finned fish phylogeny and timing of diversification.

    Science.gov (United States)

    Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

    2012-08-21

    Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

  18. Evolution of ligand specificity in vertebrate corticosteroid receptors

    Directory of Open Access Journals (Sweden)

    Deitcher David L

    2011-01-01

    Full Text Available Abstract Background Corticosteroid receptors include mineralocorticoid (MR and glucocorticoid (GR receptors. Teleost fishes have a single MR and duplicate GRs that show variable sensitivities to mineralocorticoids and glucocorticoids. How these receptors compare functionally to tetrapod MR and GR, and the evolutionary significance of maintaining two GRs, remains unclear. Results We used up to seven steroids (including aldosterone, cortisol and 11-deoxycorticosterone [DOC] to compare the ligand specificity of the ligand binding domains of corticosteroid receptors between a mammal (Mus musculus and the midshipman fish (Porichthys notatus, a teleost model for steroid regulation of neural and behavioral plasticity. Variation in mineralocorticoid sensitivity was considered in a broader phylogenetic context by examining the aldosterone sensitivity of MR and GRs from the distantly related daffodil cichlid (Neolamprologus pulcher, another teleost model for neurobehavioral plasticity. Both teleost species had a single MR and duplicate GRs. All MRs were sensitive to DOC, consistent with the hypothesis that DOC was the initial ligand of the ancestral MR. Variation in GR steroid-specificity corresponds to nine identified amino acid residue substitutions rather than phylogenetic relationships based on receptor sequences. Conclusion The mineralocorticoid sensitivity of duplicate GRs in teleosts is highly labile in the context of their evolutionary phylogeny, a property that likely led to neo-functionalization and maintenance of two GRs.

  19. ROLE OF SEROTONIN IN FISH REPRODUCTION

    Directory of Open Access Journals (Sweden)

    Parvathy ePrasad

    2015-06-01

    Full Text Available The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviours, gonadotropin release and gonadotropin-release hormone (GnRH secretion. However, the serotonin system in teleost may play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction.

  20. Large number of ultraconserved elements were already present in the jawed vertebrate ancestor.

    KAUST Repository

    Wang, Jianli; Lee, Alison P; Kodzius, Rimantas; Brenner, Sydney; Venkatesh, Byrappa

    2009-01-01

    Stephen (2008) identified 13,736 ultraconserved elements (UCEs) in placental mammals and investigated their evolution in opossum, chicken, frog, and fugu. They found that there was a massive expansion of UCEs during tetrapod evolution and the substitution rate in UCEs showed a significant decline in tetrapods compared with fugu, suggesting they were exapted in tetrapods. They considered it unlikely that these elements are ancient but evolved at a higher rate in teleost fishes. In this study, we investigated the evolution of UCEs in a cartilaginous fish, the elephant shark and show that nearly half the UCEs were present in the jawed vertebrate ancestor. The substitution rate in UCEs is higher in fugu than in elephant shark, and approximately one-third of ancient UCEs have diverged beyond recognition in teleost fishes. These data indicate that UCEs have evolved at a higher rate in teleost fishes, which may have implications for their vast diversity and evolutionary success.

  1. Large number of ultraconserved elements were already present in the jawed vertebrate ancestor.

    KAUST Repository

    Wang, Jianli

    2009-03-01

    Stephen (2008) identified 13,736 ultraconserved elements (UCEs) in placental mammals and investigated their evolution in opossum, chicken, frog, and fugu. They found that there was a massive expansion of UCEs during tetrapod evolution and the substitution rate in UCEs showed a significant decline in tetrapods compared with fugu, suggesting they were exapted in tetrapods. They considered it unlikely that these elements are ancient but evolved at a higher rate in teleost fishes. In this study, we investigated the evolution of UCEs in a cartilaginous fish, the elephant shark and show that nearly half the UCEs were present in the jawed vertebrate ancestor. The substitution rate in UCEs is higher in fugu than in elephant shark, and approximately one-third of ancient UCEs have diverged beyond recognition in teleost fishes. These data indicate that UCEs have evolved at a higher rate in teleost fishes, which may have implications for their vast diversity and evolutionary success.

  2. Two new species of zooplanktivorous haplochromine cichlids from Lake Victoria, Tanzania

    Directory of Open Access Journals (Sweden)

    Marnix de Zeeuw

    2013-01-01

    Full Text Available Two new species of zooplanktivorous haplochromine cichlids from Lake Victoria, Tanzania, are described and illustrated. These species closely resemble each other. Their affinities to other zooplanktivorous haplochromines from Lake Victoria are discussed. Haplochromis argens sp. n., which featured under nicknames (mainly H. “argens” in more than 50 papers, was caught both in the Mwanza Gulf and the Emin Pasha Gulf, whereas H. goldschmidti sp. n. was only found in the Emin Pasha Gulf. Of the latter species only males are available, but it seems unlikely that it represents a case of male colour polymorphism as several presumably unrelated characters differ in sympatry between the two species, suggesting that there is no gene flow. Statistical analysis revealed that the overall difference between the two species is greater than that between the populations from the two locations. Body depth of the two species in sympatry in the Emin Pasha Gulf was more similar than that of H. goldschmidti sp. n. and the allopatric population of H. argens sp. n. from the Mwanza Gulf, which may indicate an overall environmental effect. However, several measurements related to the width of snout and mouth differed more between the populations of the two species in sympatry than between the allopatric populations. In contrast to a group of zooplanktivorous species that recovered successfully after environmental changes in the lake, H. argens sp. n. is among a group that became extremely rare and probably is in danger of extinction; the conservation status of H. goldschmidti sp. n. is currently unknown.

  3. Fish as bioindicators in aquatic environmental pollution assessment: A case study in Lake Victoria wetlands, Uganda

    Science.gov (United States)

    Naigaga, I.; Kaiser, H.; Muller, W. J.; Ojok, L.; Mbabazi, D.; Magezi, G.; Muhumuza, E.

    Growing human population and industrialization have led to the pollution of most aquatic ecosystems and consequent deterioration in environmental water quality. Indicator organisms are needed to improve assessment programmes on the ecological impacts of anthropogenic activities on the aquatic environment. Fish have been widely documented as useful indicators of environmental water quality because of their differential sensitivity to pollution. This study investigated the environmental water quality of selected wetland ecosystems using fish as biological indicators. Fish community structure in relation to water quality was assessed in five wetlands along the shoreline of Lake Victoria from August 2006 to June 2008. Four urban wetlands were variedly impacted by anthropogenic activities while one rural wetland was less impacted, and served as a reference site. Fish species diversity, abundance and richness were assessed, and canonical correspondence analysis (CCA) was used to evaluate the relationship between the fish communities and environmental variables. Results revealed that urban effluent impacted negatively on water quality and consequently the fish community structure. A total of 29 fish species were recorded throughout the study with the lowest number of 15 species recorded in the most impacted site. Shannon diversity and Margalef species richness indices were highest at the references site and lowest at the most impacted site. Wetland haplochromis species dominated the reference site, while oreochromis species dominated the most impacted site. The inshore locations registered higher species diversity and low species richness than the offshore locations. Low dissolved oxygen, pH, secchi depth and high electrical conductivity, total phosphorous, and total nitrogen were strongly associated with the effluent-impacted sites and greatly influenced the fish community structure. This study recommends the use of fish as valuable biological indicators in aquatic

  4. Nocturnality constrains morphological and functional diversity in the eyes of reef fishes

    Directory of Open Access Journals (Sweden)

    Schmitz Lars

    2011-11-01

    Full Text Available Abstract Background Ambient light levels are often considered to drive the evolution of eye form and function. Diel activity pattern is the main mechanism controlling the visual environment of teleost reef fish, with day-active (diurnal fish active in well-illuminated conditions, whereas night-active (nocturnal fish cope with dim light. Physiological optics predicts several specific evolutionary responses to dim-light vision that should be reflected in visual performance features of the eye. Results We analyzed a large comparative dataset on morphological traits of the eyes in 265 species of teleost reef fish in 43 different families. The eye morphology of nocturnal reef teleosts is characterized by a syndrome that indicates better light sensitivity, including large relative eye size, high optical ratio and large, rounded pupils. Improved dim-light image formation comes at the cost of reduced depth of focus and reduction of potential accommodative lens movement. Diurnal teleost reef fish, released from the stringent functional requirements of dim-light vision have much higher morphological and optical diversity than nocturnal species, with large ranges of optical ratio, depth of focus, and lens accommodation. Conclusions Physical characteristics of the environment are an important factor in the evolution and diversification of the vertebrate eye. Both teleost reef fish and terrestrial amniotes meet the functional requirements of dim-light vision with a similar evolutionary response of morphological and optical modifications. The trade-off between improved dim-light vision and reduced optical diversity may be a key factor in explaining the lower trophic diversity of nocturnal reef teleosts.

  5. Using accelerometry to quantify prey attack and handling behaviours in piscivorous pike Esox lucius

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Andersson, A.; Vinterstare, J.

    2017-01-01

    Accelerometer technology was used to evaluate behaviours in the teleost ambush predator pike Esox lucius foraging on crucian carp Carassius carassius. Automated rule-based estimates of prey-size determined handling time were obtained and are compared with video-recorded behaviours. Solutions to t...... attachment and the limitations imposed by battery-time and data-logging capacities are evaluated......Accelerometer technology was used to evaluate behaviours in the teleost ambush predator pike Esox lucius foraging on crucian carp Carassius carassius. Automated rule-based estimates of prey-size determined handling time were obtained and are compared with video-recorded behaviours. Solutions to tag...

  6. Diversity of functional microornamentation in slithering geckos Lialis (Pygopodidae).

    Science.gov (United States)

    Spinner, M; Gorb, S N; Westhoff, G

    2013-12-07

    The skin of geckos is covered with countless microscopic protuberances (spines). This surface structure causes low wettability to water. During evolution, representatives of the recent gekkotan clade Pygopodidae started slithering on the ground. This manner of locomotion affected limb reduction resulting in a snake-like body. Regarding abrasion and frictional properties, a surface covered with gekkotan spines is a topography that hampers the snake-like locomotion mode. Using scanning electron microscopy, we investigated the shed skins of two pygopodid lizards, Lialis jicari (Papua snake lizard) and Lialis burtonis (Burton's legless lizard), in order to show epidermal adaptations to limbless locomotion. Our data showed that Pygopodidae differ from their relatives not only anatomically, but also in their epidermal microstructure. Scales of L. jicari have five different structural patterns on various body regions. Ventral scales have nanoridges, similar to those found on the ventralia of snakes. Surfaces of scales covering the jaw bones, have flattened spine-like microstructures that might be an adaptation to reduce abrasion. Dorsal scales have oblong microscopic bulges covered with nanoridges. Spines cover the undersides and the interstices of scales over the entire body of both species and in L. jicari also the top of dorsal head scales. Our measurements of surface wettability (surface free energy) show superhydrophobic properties of the spiny surfaces in comparison with the other microstructural patterns of other body parts.

  7. Proceedings of Indian Academy of Sciences, Section B- Vol.93

    Indian Academy of Sciences (India)

    Activity of certain enzymes of amino acid metabolism in the liver and kidney ... Rhizosphere effect of Andropogon pumilus Roxb. on soil nematodes, soil ... Adaptation to thermal stress in the freshwater eurythermal teleost ... Interactions of insect vectors with plants in relation to transmission of plant viruses - S Mukhopadyay

  8. INDUCTION AND SUPPRESSION OF CYTOCHROME P450 1A BY 3,3', 4,4', 5-PENTACHLOROBIPHENYL AND ITS RELATIONSHIP TO OXIDATIVE STRESS IN THE MARINE FISH SCUP (STENOTOMUS CHRYSOPS). (R827102)

    Science.gov (United States)

    AbstractThe planar polychlorinated biphenyl (PCB) 3,3',4,4'-tetrachlorobiphenyl (TCB) causes dose-dependent induction and post-transcriptional suppression of hepatic cytochrome P450 1A (CYP1A) in the marine teleost scup (Stenotomus chrysops). That suppr...

  9. Differential regulation of cystic fibrosis transmembrane conductance regulator and Na+,K+ -ATPase in gills of striped bass, Morone saxatilis: effect of salinity and hormones

    DEFF Research Database (Denmark)

    Madsen, Steffen; Jensen, Lars Nørholm; Tipsmark, Christian Kølbaek

    2007-01-01

    -regulated kinase (ERK) 1/2 was stimulated by EGF but not affected by IGF-I. This study is the first to report a branchial EGF response and to demonstrate a functional ERK 1/2 pathway in the teleost gill. In conclusion, CFTR and Na(+),K(+) -ATPase are differentially regulated by salinity and hormones in gills...

  10. Feeding Relationships among Six Seagrass-associated Fishes in the Northeastern Gwangyang Bay, Southern Korea

    Science.gov (United States)

    Park, Joo Myun; Kwak, Seok Nam; Han, In-Seong

    2018-03-01

    We conducted dietary analyses of six seagrass-associated fish species inhabiting northeastern Gwangyang Bay, Korea. These six species consumed a variety of benthic invertebrates and teleosts, but their preferences for different food resources varied. Although all species consumed crustaceans, the contributions of different crustacean taxa differed among the species' diets. Caridean shrimps and crabs were a significant part of the Hexagrammos agrammus and H. otakii diets, respectively, while amphipods were consumed mainly by Sebastes inermis. Caridean shrimps and prawns were abundant within the Lateolabrax japonicas diet, but were not common prey resources for Pseudopleuronectes yokohamae or S. schlegelii. Polychaetes and ophiurids were ingested by P. yokohamae, and the former prey taxon also made moderate contributions to the diets of H. agrammus and L. japonicus. With the exception of P. yokohamae, the diets of all species included teleosts. Teleosts contributed the largest proportion of the S. schlegelii diet, followed by the S. inermis and L. japonicas diets; however, H. agrammus and H. otakii rarely consumed teleosts. Non-metric multidimensional scaling (nMDS) ordination plots and permutational analysis of variance (PERMANOVA) revealed the variation in dietary composition among species and the contributions of each prey taxon. These interspecific differences in diet increase the range of food resources available to these fishes, thereby reducing competition for resources within the fish community in this region.

  11. Zebrafish Bone and General Physiology Are Differently Affected by Hormones or Changes in Gravity

    NARCIS (Netherlands)

    Aceto, J.; Nourizadeh-Lillabadi, R.; Maree, R.; Dardenne, N.; Jeanray, N.; Wehenkel, L.; Alestrom, P.; van Loon, J.J.W.A.; Muller, M.

    2015-01-01

    Teleost fish such as zebrafish (Danio rerio) are increasingly used for physiological, genetic and developmental studies. Our understanding of the physiological consequences of altered gravity in an entire organism is still incomplete. We used altered gravity and drug treatment experiments to

  12. Chemoattraction of Ichthyophthirius multifiliis (Ciliophora) theronts to host molecules

    DEFF Research Database (Denmark)

    Buchmann, Kurt; Nielsen, Michael Engelbrecht

    1999-01-01

    not attract theronts. In contrast, sera and mucus from a range of teleosts (including marine fish) were effective attractants. Fractionation by gel filtration of fish serum allowed determination of the molecular size of the attracting proteins. Further biochemical studies suggested the chemoattractants...

  13. Inter-Species Transmission of Viral Haemorrhagic Septicaemia Virus Between Turbot (Scophthalmus Maximus) and Rainbow Trout (Onchorhynchus Mykiss)

    DEFF Research Database (Denmark)

    Schönherz, A. A.; Lorenzen, Niels; Einer-Jensen, Katja

    2012-01-01

    Viral haemorrhagic septicaemia is a serious viral disease of teleost fish with high economic impact on the aquaculture industry. The disease is caused by the viral haemorrhagic septicaemia virus (VHSV), an RNA virus belonging to the family Rhabdoviridae. Compared to other rhabdoviruses infecting...

  14. Housekeeping genes for quantitative expression studies in the three-spined stickleback Gasterosteus aculeatus

    NARCIS (Netherlands)

    Hibbeler, S.; Scharsack, J.P.; Becker, S.

    2008-01-01

    Background During the last years the quantification of immune response under immunological challenges, e.g. parasitation, has been a major focus of research. In this context, the expression of immune response genes in teleost fish has been surveyed for scientific and commercial purposes. Despite the

  15. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis)

    NARCIS (Netherlands)

    Jensen, Bjarke; Elfwing, Magnus; Elsey, Ruth M.; Wang, Tobias; Crossley, Dane A.

    2016-01-01

    Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we

  16. Species composition and recruitment of tidal pool fishes in KwaZulu ...

    African Journals Online (AJOL)

    Fishes occurring in a lower shore tidal pool near Durban, South Africa, were collected using rotenone at monthly intervals for a year. Eighteen teleost families and 50 lower taxa of fishes were recorded. Cryptic Tripterygiidae, Blenniidae and Gobiidae were particularly abundant while Pomacentridae, Acanthuridae, ...

  17. The South African inshore commercial and recre- ational linefishery ...

    African Journals Online (AJOL)

    denise

    The average catch per unit effort (cpue) was low in all sectors, 1.15 kg ... fishery, 9.4 kg fisher-1 day-1 in the recreational skiboat fishery and 21.5 kg ... between 1994 and 1996 using roving creel and access .... another, evidence of a serial decline in the fishery. .... abundance of slow-growing teleost species in the catch.

  18. beta-adrenoceptors mediate inhibition of lipolysis in adipocytes of tilapia (Oreochromis mossambicus)

    NARCIS (Netherlands)

    Vianen, GJ; Obels, PP; Van Den Thillart, GEEJM; Zaagsma, J

    The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo

  19. Regulation of Na+/K+-ATPase activity by nitric oxide in the kidney and gill of the brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Tipsmark, Christian K; Madsen, Steffen S

    2003-01-01

    In teleost fish, successful osmoregulation involves controlled ion transport mechanisms in kidney and gill epithelia. In this study, the effect of nitric oxide (NO) on Na(+)/K(+)-ATPase was investigated in vitro in these two tissues in brown trout (Salmo trutta) acclimated to freshwater...

  20. Plasma proteins of Barbus holubi and Clarias gariepinus

    African Journals Online (AJOL)

    The plasma proteins of the teleosts, Barbus holubl and ClariDs gariepllUl3 were investigated by means of cel1u1ose-acetate and polyacrylamide gel electrophoresis. Characteristic patterns were obtained with both methods for each species. It was found that the application of human nomenclature to the patterns obtained in ...

  1. Adaptive bone formation in acellular vertebrae of sea bass (Dicentrarchus labrax L.)

    NARCIS (Netherlands)

    Kranenbarg, S.; Cleynenbreugel, van T.; Schipper, H.; Leeuwen, van J.L.

    2005-01-01

    Mammalian bone is an active tissue in which osteoblasts and osteoclasts balance bone mass. This process of adaptive modelling and remodelling is probably regulated by strain-sensing osteocytes. Bone of advanced teleosts is acellular yet, despite the lack of osteocytes, it is capable of an adaptive

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

    NARCIS (Netherlands)

    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

  3. Temperature-dependent expression of immune-relevant genes in rainbow trout following Yersinia ruckeri i.p. vaccination

    DEFF Research Database (Denmark)

    Raida, Martin Kristian; Buchmann, Kurt

    2007-01-01

    M in the head-kidney and Y. ruckeri specific antibodies in plasma measured by ELISA. However, no regulation of the teleost specific immunoglobulin IgT, which was generally expressed at a much lower level than IgM, could be detected. The study indicated that both innate and specific adaptive immune response...

  4. Does magnesium hardness in hatching waters affect the fertilization and hatching success of hybrid catfish eggs

    Science.gov (United States)

    Embryonic development is deemed to be the most sensitive stage in the life cycle of a teleost. As egg development takes outside the fish’s body, water hardness is one abioitic parameter, suggested to have a major effect on egg development and embryo survival. Ca2+ and Mg2+ contribute to water har...

  5. The involvement of thyroid hormone metabolism in gilthead sea bream (Sparus auratus) osmoregulation

    NARCIS (Netherlands)

    Klaren, P.H.M.; Guzman, J.M.; Mancera, J.M.; Geven, E.J.W.; Flik, G.

    2005-01-01

    We have investigated the effect of adaptation to low salinity water on the thyroid status of the euryhaline teleost, Sparus auratus. We show that, following low salinity adaptation, the plasma T(4) concentration increases and branchial deiodination activities of T(4), T(3), and rT(3) decrease.

  6. To eat or not to eat : egg-based assessment of paternity triggers fine-tuned decisions about filial cannibalism

    NARCIS (Netherlands)

    Mehlis, Marion; Bakker, Theo C. M.; Engqvist, Leif; Frommen, Joachim G.

    2010-01-01

    Filial cannibalism occurs in many animal species ranging from insects to mammals, and is especially well described in teleost fishes. Numerous causes may lead to this behaviour, e. g. certainty of paternity. However, the cues males use to assess their paternity often remain unknown. One possible way

  7. THYROCALCITONIN STUDIES IN ELASMOBRANCH FISH ...

    African Journals Online (AJOL)

    P. D. STAHL AND A. D. KENNY. Department Pharmacology and Space Sciences Research Centre,. University of Missouri, Columbia, Mo. INTRODUCTION. We recently reported a hypocalcaemic and hypophosphataemic action of mammalian thyro- caltitonin in the teleost fish Ictalurus melas (Louw, Sutton and Kenny 1967) ...

  8. Interaction between the soma and the axon terminal of horizontal cells in carp retina

    NARCIS (Netherlands)

    Kamermans, M.; van Dijk, B. W.; Spekreijse, H.

    1990-01-01

    In teleost retina, the receptive fields of horizontal cell axon terminals have a larger space constant than the receptive fields of the horizontal cell somata. Generally this difference in receptive field size is attributed to the cell coupling which is assumed to be stronger in the horizontal axon

  9. Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae, off Uruguay and northern Argentina

    Directory of Open Access Journals (Sweden)

    Santiago A. Barbini

    Full Text Available ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS and crabs in the north region (38º - 41ºS. Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

  10. Changes in the thyroid status modify the metabolite pattern of air-breathing perch (Anabas testudineus) during monocrotophos (Nuvacran) exposure

    NARCIS (Netherlands)

    Peter, V.S.; Joshua, E.K.; Wendelaar Bonga, S.E.; Peter, M.C.S.

    2007-01-01

    To address the thyroidal influence on the stress-related metabolic response in fish, we studied the metabolic pattern of airbreathing teleost, Anabas testudineus after exposing the fish to nuvacron, a monocrotophos pesticide (MCP). Significant changes in the levels of some diagnostically important

  11. Microscopic recognition and identification of fish meal in compound feeds

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Prins, Theo; Rhee, van de N.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2017-01-01

    Fish meal is an accepted ingredient in compound feed. Unauthorised application is primarily enforced by visual inspection, i.e., microscopy. In order to document the visually available diversity, fragments of bones and scales of 17 teleost fish species belonging to seven different orders were

  12. Phylogenetic Diversity of Cephalopoda (Animalia:Mollusca) Along the Saudi Arabian Red Sea Coastline

    KAUST Repository

    Byron, Gordon

    2016-01-01

    ecosystems, serving as part of the food chain and exhibiting population increases due to targeted teleost fisheries and global climate change. In order to assess the biodiversity of Cephalopoda in the Saudi Arabian Red Sea, 87 specimens were collected from 25

  13. Copper-Based Torpedo Guidance Wire: Applications and Environmental Considerations

    Science.gov (United States)

    2013-06-01

    whose swimming or feeding behaviors place them near the ocean floor. Additionally, an emphasis was placed on those animals with benthic feeding habits ...may suck in their prey and swallow them whole (Pitman, 2002; Heyning and Mead, 1996). However their feeding habits do not include digging through... feed on a various epipelagic and mesopelagic cephalopods, teleosts, Merluccius productus, crustaceans , elasmobranchs, cyclostomes, and tunicates

  14. Identification and analysis of genes involved in bone formation – a genetic approach in zebrafish –

    NARCIS (Netherlands)

    Spoorendonk, K.M.

    2009-01-01

    For many years bone research has been mainly performed in mice, chicken, cell culture systems, or human material from the clinic. In this thesis, we make use of the zebrafish (Danio rerio), a relatively new model system in this field. This small teleost offers possibilities which makes it a great

  15. Identification and analysis of genes involved in bone formation - a genetic approach in zebrafish -

    NARCIS (Netherlands)

    Spoorendonk, K.M.

    2009-01-01

    For many years bone research has been mainly performed in mice, chicken, cell culture systems, or human material from the clinic. In this thesis, we make use of the zebrafish (Danio rerio), a relatively new model system in this field. This small teleost offers possibilities which makes it a great

  16. Does the endangered Knysna seahorse, Hippocampus capensis ...

    African Journals Online (AJOL)

    Abstract. The Knysna seahorse, Hippocampus capensis, is an endangered teleost confined to three South African estuaries. Its abundance within these systems is low and distributions are patchy. Consequently, monitoring population sizes is labour- intensive. The aim of this study was to establish if Knynsa seahorses are ...

  17. Impaired swim bladder inflation in early-life stage fathead minnows exposed to a deiodinase inhibitor, iopanoic acid

    Science.gov (United States)

    The thyroid axis plays a critical role in teleost fish development. The present study investigated whether inhibition of deiodinase, the enzyme which converts thyroxine (T4), to the more biologically-active form, 3,5,3'-triiodothyronine (T3), would impact inflation of the posteri...

  18. First record of Neobenedenia melleni (Monogenea: Capsalidae) in sea-farmed cobia (Rachycentron canadum) in Brazil.

    Science.gov (United States)

    Kerber, Claudia Ehlers; Sanches, Eduardo Gomes; Santiago, Mauricio; Luque, José Luis

    2011-01-01

    Neobenedenia melleni (MacCallum, 1927) (Monogenea) is a widespread pathogen in marine teleost cultures all over the world. The present paper reports this parasite species in farmed cobia (Rachycentron canadum) in Brazil, for the first time. Some comments on preventive actions for avoiding the disease are made.

  19. Exuberant granulation tissue response associated with Neobenedenia sp. (Monogenea: Capsalidae) infestation in two cobia, Rachycentron canadum (Linnaeus).

    Science.gov (United States)

    Hurley-Sanders, J; Harms, C; Christiansen, E; Clarke, E; Law, J

    2016-03-01

    Monogenean parasite infestations are common in captive marine teleosts, and are generally found on the skin and gills. This report describes an unusual pathological presentation of exuberant granulation tissue of the gills, suspected to be related to Neobenedenia infestation in two cobia housed together at a North Carolina aquarium. © 2015 John Wiley & Sons Ltd.

  20. Effects of graded taurine levels on juvenile cobia

    Science.gov (United States)

    Taurine, which has multiple important physiological roles in teleost fish and mammals, is an amino acid not found in alternative protein sources not derived from animals. Although taurine is found in fish-meal-based feeds, its high water solubility leads to lower taurine levels in reduction-process-...

  1. Search Results | Page 63 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Results 621 - 630 of 8519 ... Cadmium and calcium transport along the gastro-intestinal tract of rainbow trout : more than "gut feelings" on mechanisms of uptake. Teleosts take ... Tense collaborations and exchange interrupted : gendered participation in ecological agriculture projects in post-neoliberal(?) Bolivia. Even as the ...

  2. Evolutionary conservation of mannan-binding lectin (MBL) in bony fish

    DEFF Research Database (Denmark)

    Kania, Per Walter; Sørensen, Rasmus Reng; Koch, Claus

    2010-01-01

    The complement system of fish is generally as complex as in mammals, and in addition Teleost fish often possess several genes encoding different subtypes of a given complement component, such as C3-1, C3-3 and C3-4. Initiators of both the classical (C1) and alternative pathway (factor B) have bee...

  3. L-rhamnose-binding lectins (RBLs) in Nile tilapia, Oreochromis niloticus: characterization and expression profiling in mucosal tissues

    Science.gov (United States)

    Rhamnose-binding lectins (RBLs) are crucial elements associated with innate immune responses to infections and have been characterized from a variety of teleost fishes. Our previous work highlighted a major role of a RBL (IpRBL1a) in mediating F. columnare adhesion and IpRBL1a showed higher expressi...

  4. Abstracts of Papers Submitted in 1978 for Publication,

    Science.gov (United States)

    1978-01-01

    210 and Polonium - 210 as Marine...34.." . .." . .• . ’... . .. X. . ’-"..’-..- . - .>I-.A7.’ -~. .-.. .. . .< .- , ,.. . -’ ~ ~ \\ - & . .x. \\ , ,, .. . . . ... . .. . C-22 i- LEAD- 210 AND POLONIUM - 210 AS...Herbivore Food Preference B-13 Mary E. Nicotri High Benzo(a)pyrene Hydroxylase Activity in the Marine Teleost Fish Stenotomus versicotor . . .

  5. EVALUATION OF ENDOGENOUS HORMONES AND A XENOBIOTIC PESTICIDE ON SHEEPSHEAD MINNOW GROWTH USING MOLECULAR BIOLOGICAL TECHNIQUES

    Science.gov (United States)

    Presented at the 131st Annual Meeting of the American Fisheries Society, "2001: A Fisheries Odyssey: The Journey of Science and Education Continues," 19-23 August 2001, Phoenix, AZ. 1 p.We have developed a teleost model to screen physiological effects of endocrine disrup...

  6. USE OF MOLECULAR BIOLOGICAL TECHNIQUES TO EVALUATE EFFECT OF ENDOGENOUS HORMONES AND A XENOBIOTIC PESTICIDE ON GROWTH OF SHEEPSHEAD MINNOW

    Science.gov (United States)

    We have developed a teleost model to screen physiological effects of endocrine disrupting chemicals (EDCs) on somatic growth. Growth is largely controlled by the endocrine system via the growth-hormone releasing hormone (GRF) - growth hormone (GH) - insulin-like growth factor (IG...

  7. Retinal processing and opponent mechanisms mediating ultraviolet polarization sensitivity in rainbow trout (Oncorhynchus mykiss)

    NARCIS (Netherlands)

    Ramsden, Samuel D.; Anderson, Leslie; Mussi, Martina; Kamermans, Maarten; Hawryshyn, Craig W.

    2008-01-01

    A number of teleost fishes have photoreceptor mechanisms to detect linearly polarized light. We studied the neuronal mechanism underlying this ability. It was found that a polarized signal could be detected in rainbow trout (Oncorhynchus mykiss) both in the electroretinogram (ERG) and in the

  8. Molecular cloning, characterization and expression analysis of TLR9, MyD88 and TRAF6 genes in common carp (Cyprinus carpio)

    Science.gov (United States)

    Induction of innate immune pathways is critical for early host defense but there is limited understanding of how teleost fish recognize pathogen molecules and activate these pathways. In mammals, cells of the innate immune system detect pathogenic molecular structures using pattern recognition rece...

  9. Plasma lactate and stress hormones in common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) during stepwise decreasing oxygen levels

    NARCIS (Netherlands)

    Vianen, GJ; Van den Thillart, GEEJM; Van Kampen, M; Van Heel, TI; Steffens, AB

    By measuring the lactate response it is possible to determine whether a teleost is able to adapt to a certain oxygen level. It is hypothesized that recovery will occur at oxygen levels above the critical oxygen level (PO2)(crit) reflected by a transient lactate increase. In contrast, continuous

  10. 14. Pisces, Reptilia and Aves

    NARCIS (Netherlands)

    Beaufort, de L.F.

    1931-01-01

    In the following list of fishes and reptiles, known to occur as fossils in the Indoaustralian Archipelago, I have chiefly followed Smith Woodward (Bibl. 18) for the taxonomy. The teleosts, however, have been arranged according to Boulenger (The Cambridge Natural History, Vol. VII, 1904), with some

  11. Involvement of phospholipase C and intracellular calcium signaling in the gonadotropin-releasing hormone regulation of prolactin release from lactotrophs of tilapia (Oreochromis mossambicus)

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Weber, G M; Strom, C N

    2005-01-01

    Gonadotropin-releasing hormone (GnRH) is a potent stimulator of prolactin (PRL) secretion in various vertebrates including the tilapia, Oreochromis mossambicus. The mechanism by which GnRH regulates lactotroph cell function is poorly understood. Using the advantageous characteristics of the teleost...

  12. Hydrodynamics of suction feeding in fish

    NARCIS (Netherlands)

    Muller, M.

    1983-01-01

    1. Suction feeding is the dominant way to obtain food in teleosts. Its high demands on structures due to the required velocities and forces leads to the expectation that a biophysical analysis will aid to reveal the adaptive significance of head and body structures related to this

  13. Uptake and loss of absorbed dissolved cadmium to Clarias ...

    African Journals Online (AJOL)

    GRACE

    2006-06-16

    Jun 16, 2006 ... Res NATO Sci. Comm. Conf. 7: 187-195 London. Eisler R, Gardner GR (1973). Acute toxicology to an estuarine teleost of mistures of cadmuim, copper, and zinc salts. J. Fish. Biol. 5: 131 – 142. Eisler R (1974). Radio cadmium exchange with seawater by. Fundulus heteroclitus (L) (Pisces: Cyprinodontidae) ...

  14. Evolution of the osteoblast: skeletogenesis in gar and zebrafish

    Directory of Open Access Journals (Sweden)

    Eames B Frank

    2012-03-01

    Full Text Available Abstract Background Although the vertebrate skeleton arose in the sea 500 million years ago, our understanding of the molecular fingerprints of chondrocytes and osteoblasts may be biased because it is informed mainly by research on land animals. In fact, the molecular fingerprint of teleost osteoblasts differs in key ways from that of tetrapods, but we do not know the origin of these novel gene functions. They either arose as neofunctionalization events after the teleost genome duplication (TGD, or they represent preserved ancestral functions that pre-date the TGD. Here, we provide evolutionary perspective to the molecular fingerprints of skeletal cells and assess the role of genome duplication in generating novel gene functions. We compared the molecular fingerprints of skeletogenic cells in two ray-finned fish: zebrafish (Danio rerio--a teleost--and the spotted gar (Lepisosteus oculatus--a "living fossil" representative of a lineage that diverged from the teleost lineage prior to the TGD (i.e., the teleost sister group. We analyzed developing embryos for expression of the structural collagen genes col1a2, col2a1, col10a1, and col11a2 in well-formed cartilage and bone, and studied expression of skeletal regulators, including the transcription factor genes sox9 and runx2, during mesenchymal condensation. Results Results provided no evidence for the evolution of novel functions among gene duplicates in zebrafish compared to the gar outgroup, but our findings shed light on the evolution of the osteoblast. Zebrafish and gar chondrocytes both expressed col10a1 as they matured, but both species' osteoblasts also expressed col10a1, which tetrapod osteoblasts do not express. This novel finding, along with sox9 and col2a1 expression in developing osteoblasts of both zebrafish and gar, demonstrates that osteoblasts of both a teleost and a basally diverging ray-fin fish express components of the supposed chondrocyte molecular fingerprint. Conclusions Our

  15. Social regulation of male reproductive plasticity in an African cichlid fish.

    Science.gov (United States)

    Maruska, Karen P; Fernald, Russell D

    2013-12-01

    Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.

  16. A fossil unicorn crestfish (Teleostei, Lampridiformes, Lophotidae) from the Eocene of Iran.

    Science.gov (United States)

    Davesne, Donald

    2017-01-01

    Lophotidae, or crestfishes, is a family of rare deep-sea teleosts characterised by an enlarged horn-like crest on the forehead. They are poorly represented in the fossil record, by only three described taxa. One specimen attributed to Lophotidae has been described from the pelagic fauna of the middle-late Eocene Zagros Basin, Iran. Originally considered as a specimen of the fossil lophotid † Protolophotus , it is proposed hereby as a new genus and species † Babelichthys olneyi , gen. et sp. nov., differs from the other fossil lophotids by its relatively long and strongly projecting crest, suggesting a close relationship with the modern unicorn crestfish, Eumecichthys . This new taxon increases the diversity of the deep-sea teleost fauna to which it belongs, improving our understanding of the taxonomic composition of the early Cenozoic mesopelagic ecosystems.

  17. A fossil unicorn crestfish (Teleostei, Lampridiformes, Lophotidae from the Eocene of Iran

    Directory of Open Access Journals (Sweden)

    Donald Davesne

    2017-06-01

    Full Text Available Lophotidae, or crestfishes, is a family of rare deep-sea teleosts characterised by an enlarged horn-like crest on the forehead. They are poorly represented in the fossil record, by only three described taxa. One specimen attributed to Lophotidae has been described from the pelagic fauna of the middle-late Eocene Zagros Basin, Iran. Originally considered as a specimen of the fossil lophotid †Protolophotus, it is proposed hereby as a new genus and species †Babelichthys olneyi, gen. et sp. nov., differs from the other fossil lophotids by its relatively long and strongly projecting crest, suggesting a close relationship with the modern unicorn crestfish, Eumecichthys. This new taxon increases the diversity of the deep-sea teleost fauna to which it belongs, improving our understanding of the taxonomic composition of the early Cenozoic mesopelagic ecosystems.

  18. Stomach contents of cetaceans incidentally caught along Mangalore and Chennai coasts of India

    Science.gov (United States)

    Krishnan, Anoop A.; Yousuf, K. S.; Kumaran, P. L.; Harish, N.; Anoop, B.; Afsal, V. V.; Rajagopalan, M.; Vivekanandan, E.; Krishnakumar, P. K.; Jayasankar, P.

    2008-03-01

    The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purseseine fisheries along Mangalore and Chennai coasts (India) between 2004 and 2006 were examined. The whole stomach (fore-gut, mid-gut and hind-gut) was examined in all cases. Prey remains (666 prey items comprising six species of teleosts, one crustacean and one squid species) were found in the stomachs of eight individuals (the remaining 24 stomachs were found to be empty). All cetaceans were found to feed mostly on teleosts with wide range of trophic levels. Based on an index that included frequency of occurrence, percentage by number and by weight, the oil sardine Sardinella longiceps was the main prey in the sample. Cetaceans appear to favour both pelagic as well as demersal prey, possibly indicating surface and benthic feeding habits.

  19. Global patterns in marine predatory fish

    DEFF Research Database (Denmark)

    van Denderen, Pieter Daniël; Lindegren, Martin; MacKenzie, Brian

    2017-01-01

    known. Here, we show how latitudinal differences in predatory fish can essentially be explained by the inflow of energy at the base of the pelagic and benthic food chain. A low productive benthic energy pathway favours large pelagic species, whereas equal productivities support large demersal......Large teleost (bony) fish are a dominant group of predators in the oceans and constitute a major source of food and livelihood for humans. These species differ markedly in morphology and feeding habits across oceanic regions; large pelagic species such as tunas and billfish typically occur...... in the tropics, whereas demersal species of gadoids and flatfish dominate boreal and temperate regions. Despite their importance for fisheries and the structuring of marine ecosystems, the underlying factors determining the global distribution and productivity of these two groups of teleost predators are poorly...

  20. Feeding ecology of elasmobranch species in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Alessandra F. Viana

    2017-07-01

    Full Text Available ABSTRACT The feeding ecology of five elasmobranch species was studied on the southern coast of Rio de Janeiro, southwestern Atlantic Ocean. The specimens were caught with a trawl or bottom longline between January 2006 and August 2007. The diets of Psammobatis rutrum and Psammobatis extenta appeared to be basically carcino-benthophagous, with a very small niche width. Rioraja agassizii was basically carcino/ichthyo-benthophagous, also with a narrow niche, including teleost fish and shrimp, but in different proportions according to age and sex. Rhizoprionodon lalandii was ichthyophagous, not influenced by age or sex. The analyses of these species and Atlantoraja cyclophora indicated two trophic groups: one composed of the smaller rays, P. extenta and P. rutrum, which basically fed on small crustaceans, polychaetes and nematodes; and the other of R. lalandii and the larger rays R. agassizii and A. cyclophora, which preyed on teleost fish and brachyurans.

  1. Partitioning of body fluids in the Lake Nicaragua shark and three marine sharks.

    Science.gov (United States)

    THORSON, T B

    1962-11-09

    The relative volumes of major body fluids of freshwater and marine sharks are remarkably similar in spite of the differences in external medium and in osmotic pressure of body fluids. The small differences detected are in agreement with differences reported in comparisons of freshwater and marine teleosts: a slightly higher total water content and a smiller ratio of extracellular to intracellular fluids in freshwater forms.

  2. A second glucagon in the pancreatic islets of the daddy sculpin Cottus scorpius.

    Science.gov (United States)

    Cutfield, S M; Cutfield, J F

    1993-09-01

    The peptide hormone glucagon has been isolated from the islet tissue (Brockmann bodies) of the teleost Cottus scorpius (daddy sculpin) and sequenced. The sequence is HSEGTSNDYSKYLEDRKAQDFVQWLMNN differing at four positions from the glucagon found earlier in the same species by Conlon and coworkers (1987b, Eur. J. Biochem, 164, 117-122). Thus sculpin, in common with anglerfish, possesses two distinct glucagons. Comparative sequence data are presented as a phylogenetic tree.

  3. Osmoregulation and expression of ion transport proteins and putative claudins in the gill of southern flounder (Paralichthys lethostigma)

    DEFF Research Database (Denmark)

    Tipsmark, Christian K; Luckenbach, J Adam; Madsen, Steffen S

    2008-01-01

    The southern flounder is a euryhaline teleost that inhabits ocean, estuarine, and riverine environments. We investigated the osmoregulatory strategy of juvenile flounder by examining the time-course of homeostatic responses, hormone levels, and gill Na(+),K(+)-ATPase and Na(+),K(+),2Cl(-) cotrans...... process is associated with changes in branchial expression of ion transport and putative tight junction claudin proteins known to regulate epithelial permeability in mammalian vertebrates....

  4. Development of the Early Axon Scaffold in the Rostral Brain of the Small Spotted Cat Shark (Scyliorhinus canicula) Embryo

    OpenAIRE

    Ware, Michelle; Waring, Colin P.; Schubert, Frank R.

    2014-01-01

    International audience; The cat shark is increasingly used as a model for Chondrichthyes, an evolutionarily important sister group of the bony vertebrates that include teleosts and tetrapods. In the bony vertebrates, the first axon tracts form a highly conserved early axon scaffold. The corresponding structure has not been well characterised in cat shark and will prove a useful model for comparative studies. Using pan-neural markers, the early axon scaffold of the cat shark, Scyliorhinus cani...

  5. Relaxin-related gene expression differs between anadromous and stream-resident stickleback (Gasterosteus aculeatus) following seawater transfer.

    Science.gov (United States)

    Kusakabe, Makoto; Ishikawa, Asano; Kitano, Jun

    2014-09-01

    Relaxin (RLN) is a hormone that was originally identified as a regulator of pregnancy and reproduction. However, recent mammalian studies have demonstrated that relaxins also have potent osmoregulatory actions. In mammals, six relaxin family peptides have been identified: RLN1/2, RLN3, insulin-like peptide (INSL) 3, INSL4, INSL5, and INSL6. Previous genome database searches have revealed that teleosts also possess multiple relaxin family genes. However, the functions of these relaxin family peptides in teleosts remain unclear. In order to gain insight into the osmoregulatory functions of teleost relaxins, we studied the relaxin family peptides in euryhaline three-spined sticklebacks (Gasterosteus aculeatus), which have diversified into a variety of ecotypes. Rln3a, rln3b, and rln transcripts were abundant in the stickleback brain, whereas insl5b transcript levels were highest in the intestine among tissues. Seawater challenge experiments showed that transcript levels of rln3a, rln3b, and rln in the brain changed significantly after seawater transfer. Particularly, rln3b showed different patterns of temporal changes between anadromous and stream-resident morphs. The transcript levels of relaxin family peptide receptors, rxfp1, rxfp2b, rxfp3-2a, and rxfp3-2b, did not exhibit substantial changes in the brain, although these were constantly higher in the anadromous morph than the stream-resident morph. These results suggest that stickleback relaxin systems are differentially regulated by salinity signals, at least at the transcriptional level, and anadromous and stream-resident morphs differ in relaxin signaling pathways. The differences in the expression of relaxin-related genes between these two morphs provide a foundation for further exploration of the osmoregulatory function of relaxins in teleosts. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Multiplicity of Buc copies in Atlantic salmon contrasts with loss of the germ cell determinant in primates, rodents and axolotl

    OpenAIRE

    Skugor, Adrijana; Tveiten, Helge; Johnsen, Hanne; Andersen, Øivind

    2016-01-01

    Background The primordial germ cells (PGCs) giving rise to gametes are determined by two different mechanisms in vertebrates. While the germ cell fate in mammals and salamanders is induced by zygotic signals, maternally delivered germ cell determinants specify the PGCs in birds, frogs and teleost fish. Assembly of the germ plasm in the oocyte is organized by the single Buc in zebrafish, named Velo1 in Xenopus, and by Oskar in Drosophila. Secondary loss of oskar in several insect lineages coin...

  7. Five new species of philometrid nematodes (Philometridae) from marine fishes off Java, Indonesia

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; WALTER, T.; YUNIAR, A. T.

    2012-01-01

    Roč. 59, č. 2 (2012), s. 115-130 ISSN 0015-5683 R&D Projects: GA ČR GBP505/12/G112 Institutional research plan: CEZ:AV0Z60220518 Keywords : parasitic nematodes * Philometra * Philometroides * taxonomy * teleost fish Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.515, year: 2012 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=22049

  8. Comparative feeding ecology of bull sharks (Carcharhinus leucas in the coastal waters of the southwest Indian Ocean inferred from stable isotope analysis.

    Directory of Open Access Journals (Sweden)

    Ryan Daly

    Full Text Available As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ(13C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ(13C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range.

  9. Estudio de la morfometría de las sagittae en poblaciones de sciaenidos marinos de aguas cálidas del Perú y aguas templado-frías de Argentina

    OpenAIRE

    Volpedo, A.

    2001-01-01

    Otoliths (sagitta, asteriscus and lapillus)are complex structures composed of calcium carbonate, other minerals, and a protein matrix. Otoliths are located in the internal ear of the teleost fishes. The shape and structure of otoliths are specific for each species. For this reason, otoliths are used to identify species in biological and ecological studies.Sciaenids conform a group of fishes of commercial importance, so the handling of this resource is a high-priority topic for the local and n...

  10. Organ-related distribution of phospholemman in the spiny dogfish Squalus acanthias.

    Science.gov (United States)

    Schuurmans Stekhoven, F M A H; Grell, E; Atsma, W; Flik, G; Wendelaar Bonga, S E

    2003-04-18

    The distribution of phospholemman among nine different organs of the spiny dogfish (Squalus acanthias) has been determined on the basis of Western blotting of microsomal material. Only rectal gland (100%), brain (43%), heart (18%), and kidney (19%) (abundancies as percent of the concentration in rectal gland) contained the protein, but not gill and colon. The relative abundance in the brain makes this organ a preferential test system for phospholemman in fishes that lack a rectal gland like teleosts.

  11. Chronic Exposure to Tributyltin Induces Brain Functional Damage in Juvenile Common Carp (Cyprinus carpio)

    OpenAIRE

    Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

    2015-01-01

    The aim of the present study was to investigate the effect of Tributyltin (TBT) on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase), Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide) in the brain of common carp were evaluated. Fish we...

  12. Dietary effects of Ca-zeolite supplementation on some blood and ...

    African Journals Online (AJOL)

    smyo

    to the Al, Si, Zn, Na or K concentrations of zeolite, because these minerals have been ... The SiO2, Al2O3, H2O related to loss on ignition, and CaO are the essential ...... The effect of interaction between narasin and nicarbazin with zeolite ... Protective role of zeolite on short- and long-term lead toxicity in the teleost fish.

  13. Parental care compromises feeding in the pumpkinseed (Lepomis gibbosus)

    Czech Academy of Sciences Publication Activity Database

    Zieba, G.; Dukowska, M.; Przybylski, M.; Fox, M. G.; Smith, Carl

    2018-01-01

    Roč. 105, č. 3-4 (2018), č. článku 26. ISSN 0028-1042 Institutional support: RVO:68081766 Keywords : filial cannibalism * phenotypic plasticity * seasonal-variation * teleost fishes * patterns * sunfish * populations * tactics * costs * food * Alternative mating strategy * Bayesian inference * Male mating polymorphism * Parental care * Territoriality Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 1.191, year: 2016

  14. Grass Carp Laboratory of Genetics and Physiology 2 Serves As a Negative Regulator in Retinoic Acid-Inducible Gene I- and Melanoma Differentiation-Associated Gene 5-Mediated Antiviral Signaling in Resting State and Early Stage of Grass Carp Reovirus Infection

    OpenAIRE

    Rao, Youliang; Wan, Quanyuan; Yang, Chunrong; Su, Jianguo

    2017-01-01

    Laboratory of genetics and physiology 2 (LGP2) is a key component of RIG-I-like receptors (RLRs). However, the lack of the caspase recruitment domains (CARDs) results in its controversial functional performance as a negative or positive regulator in antiviral responses. Especially, no sufficient evidence uncovers the functional mechanisms of LGP2 in RLR signaling pathways in teleost. Here, negative regulation mechanism of LGP2 in certain situations in retinoic acid-inducible gene I (RIG-I) an...

  15. Adaptations of semen characteristics and sperm motility to harsh salinity : extreme situations encountered by the euryhaline tilapia Sarotherodon melanotheron heudelotii (Dumeril, 1859)

    OpenAIRE

    Legendre, Marc; Alavi, S. M. H.; Dzyuba, B.; Linhart, O.; Prokopchuk, G.; Cochet, Christophe; Dugué, Rémi; Cosson, J.

    2016-01-01

    In most teleost fishes, sperm cells are quiescent in the seminal plasma and are activated by either a drop (fresh water fish) or an increase in osmolality (marine fish) when released in the water. It is most interesting to examine how the mechanisms of sperm motility activation can adapt to a broad range of salinities, as applies to some euryhaline species, and particularly to the tilapia Sarotherodon melanotheron heudelotii, which can reproduce at salinities from 0 up to 120 in the wild. Her...

  16. Seahorses in focus: local ecological knowledge of seahorse-watching operators in a tropical estuary

    OpenAIRE

    Ternes, Maria L. F.; Gerhardinger, Leopoldo C.; Schiavetti, Alexandre

    2016-01-01

    Background Seahorses are endangered teleost fishes under increasing human pressures worldwide. In Brazil, marine conservationists and policy-makers are thus often skeptical about the viability of sustainable human-seahorse interactions. This study focuses on local ecological knowledge on seahorses and the implications of their non-lethal touristic use by a coastal community in northeastern Brazil. Community-based seahorse-watching activities have been carried out in Maraca?pe village since 19...

  17. A miniaturized threshold-triggered acceleration data-logger for recording burst movements of aquatic animals

    OpenAIRE

    Huveneers, Charlie; Matsuo, Ayane; Kawabe, Ryo; Watanabe, Yuuki; Nishiumi, Nozomi; Payne, Nicholas; Kawabata, Yuuki

    2017-01-01

    Animal-borne accelerometers are effective tools for quantifying the kinematics of animal behaviors, such as swimming, running, and flying, under natural conditions. However, quantifying burst movements of small and agile aquatic animals (e.g., small teleost fish), such as during predatory behavior, or while fleeing, remains challenging. To capture the details of burst movements, accelerometers need to sample at a very high frequency, which will inevitably shorten the duration of the recording...

  18. Molecular cloning, functional characterization, and evolutionary analysis of vitamin D receptors isolated from basal vertebrates.

    Directory of Open Access Journals (Sweden)

    Erin M Kollitz

    Full Text Available The vertebrate genome is a result of two rapid and successive rounds of whole genome duplication, referred to as 1R and 2R. Furthermore, teleost fish have undergone a third whole genome duplication (3R specific to their lineage, resulting in the retention of multiple gene paralogs. The more recent 3R event in teleosts provides a unique opportunity to gain insight into how genes evolve through specific evolutionary processes. In this study we compare molecular activities of vitamin D receptors (VDR from basal species that diverged at key points in vertebrate evolution in order to infer derived and ancestral VDR functions of teleost paralogs. Species include the sea lamprey (Petromyzon marinus, a 1R jawless fish; the little skate (Leucoraja erinacea, a cartilaginous fish that diverged after the 2R event; and the Senegal bichir (Polypterus senegalus, a primitive 2R ray-finned fish. Saturation binding assays and gel mobility shift assays demonstrate high affinity ligand binding and classic DNA binding characteristics of VDR has been conserved across vertebrate evolution. Concentration response curves in transient transfection assays reveal EC50 values in the low nanomolar range, however maximum transactivational efficacy varies significantly between receptor orthologs. Protein-protein interactions were investigated using co-transfection, mammalian 2-hybrid assays, and mutations of coregulator activation domains. We then combined these results with our previous study of VDR paralogs from 3R teleosts into a bioinformatics analysis. Our results suggest that 1, 25D3 acts as a partial agonist in basal species. Furthermore, our bioinformatics analysis suggests that functional differences between VDR orthologs and paralogs are influenced by differential protein interactions with essential coregulator proteins. We speculate that we may be observing a change in the pharmacodynamics relationship between VDR and 1, 25D3 throughout vertebrate evolution that may

  19. Proteomic analysis of three gonad types of swamp eel reveals genes differentially expressed during sex reversal

    OpenAIRE

    Sheng, Yue; Zhao, Wei; Song, Ying; Li, Zhigang; Luo, Majing; Lei, Quan; Cheng, Hanhua; Zhou, Rongjia

    2015-01-01

    A variety of mechanisms are engaged in sex determination in vertebrates. The teleost fish swamp eel undergoes sex reversal naturally and is an ideal model for vertebrate sexual development. However, the importance of proteome-wide scanning for gonad reversal was not previously determined. We report a 2-D electrophoresis analysis of three gonad types of proteomes during sex reversal. MS/MS analysis revealed a group of differentially expressed proteins during ovary to ovotestis to testis transf...

  20. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  1. The Fanconi anemia/BRCA gene network in zebrafish: Embryonic expression and comparative genomics

    OpenAIRE

    Titus, Tom A.; Yan, Yi-Lin; Wilson, Catherine; Starks, Amber M.; Frohnmayer, Jonathan D.; Canestro, Cristian; Rodriguez-Mari, Adriana; He, Xinjun; Postlethwait, John H.

    2008-01-01

    Fanconi anemia (FA) is a genic disease resulting in bone marrow failure, high cancer risks, and infertility, and developmental anomalies including microphthalmia, microcephaly, hypoplastic radius and thumb. Here we present cDNA sequences, genetic mapping, and genomic analyses for the four previously undescribed zebrafish FA genes (fanci, fancj, fancm, and fancn, and show that they reverted to single copy after the teleost genome duplication. We tested the hypothesis that FA genes are expresse...

  2. Embryonic and larval development in the Midas cichlid fish species flock (Amphilophus spp.): a new evo-devo model for the investigation of adaptive novelties and species differences.

    Science.gov (United States)

    Kratochwil, Claudius F; Sefton, Maggie M; Meyer, Axel

    2015-02-26

    Central American crater lake cichlid fish of the Midas species complex (Amphilophus spp.) are a model system for sympatric speciation and fast ecological diversification and specialization. Midas cichlids have been intensively analyzed from an ecological and morphological perspective. Genomic resources such as transcriptomic and genomic data sets, and a high-quality draft genome are available now. Many ecologically relevant species-specific traits and differences such as pigmentation and cranial morphology arise during development. Detailed descriptions of the early development of the Midas cichlid in particular, will help to investigate the ontogeny of species differences and adaptations. We describe the embryonic and larval development of the crater lake cichlid, Amphilophus xiloaensis, until seven days after fertilization. Similar to previous studies on teleost development, we describe six periods of embryogenesis - the zygote, cleavage, blastula, gastrula, segmentation, and post-hatching period. Furthermore, we define homologous stages to well-described teleost models such as medaka and zebrafish, as well as other cichlid species such as the Nile tilapia and the South American cichlid Cichlasoma dimerus. Key morphological differences between the embryos of Midas cichlids and other teleosts are highlighted and discussed, including the presence of adhesive glands and different early chromatophore patterns, as well as variation in developmental timing. The developmental staging of the Midas cichlid will aid researchers in the comparative investigation of teleost ontogenies. It will facilitate comparative developmental biological studies of Neotropical and African cichlid fish in particular. In the past, the species flocks of the African Great Lakes have received the most attention from researchers, but some lineages of the 300-400 species of Central American lakes are fascinating model systems for adaptive radiation and rapid phenotypic evolution. The availability

  3. Transcriptome sequencing of Atlantic salmon (Salmo salar L.) notochord prior to development of the vertebrae provides clues to regulation of positional fate, chordoblast lineage and mineralisation

    OpenAIRE

    Wang, Shou; Furmanek, Tomasz; Kryvi, Harald; Krossøy, Christel; Totland, Geir Kåre; Grotmol, Sindre; Wargelius, Anna

    2014-01-01

    Background In teleosts such as Atlantic salmon (Salmo salar L.), segmentation and subsequent mineralisation of the notochord during embryonic stages are essential for normal vertebrae formation. However, the molecular mechanisms leading to segmentation and mineralisation of the notochord are poorly understood. The aim of this study was to identify genes/pathways acting in gradients over time and along the anterior-posterior axis during notochord segmentation and immediately prior to mineralis...

  4. Structural characterization and comparative analysis of human and piscine cartilage acidic protein (CRTAC1/CRTAC2)

    OpenAIRE

    Guerreiro, Marta Lúcia Amaro

    2014-01-01

    Dissertação de mestrado, Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014 CRTAC (Cartilage Acidic Protein) firstly identified as a chondrocyte marker in humans and implicated in a number of diseases. This ancient protein is present from prokaryotes to vertebrates and the teleost are the only group that contain duplicates (CRTAC1/CRTAC2). The structure of CRTACs is poorly characterized and was the starting point of the present study. To establi...

  5. Maternally transferred mercury in wild largemouth bass, Micropterus salmoides

    International Nuclear Information System (INIS)

    Sackett, Dana K.; Aday, D. Derek; Rice, James A.; Cope, W. Gregory

    2013-01-01

    Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g −1 ) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with −1 Hg had low levels of Hg in eggs; those with Hg >0.37 μg g −1 showed a direct relationship between egg and muscle Hg (Log 10 egg Hg = −1.03 + 1.18 * log 10 muscle tissue Hg + 2.15 * (log 10 muscle tissue Hg + 0.35) 2 ). We also report higher maternal transfer (0.2–13.2%) and higher ratios of egg to muscle tissue Hg (4–52%) and egg to whole body Hg concentrations (7–116%) than previously observed for teleost fish. Highlights: •Previous work suggests maternal Hg transfer in teleosts is consistently low. •We provide evidence that teleosts can have high maternal Hg transfer. •Females with low Hg had similar and low concentrations of Hg in their eggs. •Females with high Hg had Hg in eggs that increased with somatic tissue Hg. •Egg Hg from high Hg females exceeded adverse effect levels. -- Capsule: Here we report higher maternal transfer and higher ratios of egg to muscle tissue Hg than previously observed for teleost fish

  6. Different expression patterns of renal Na+/K+-ATPase α-isoform-like proteins between tilapia and milkfish following salinity challenges.

    Science.gov (United States)

    Yang, Wen-Kai; Chung, Chang-Hung; Cheng, Hui Chen; Tang, Cheng-Hao; Lee, Tsung-Han

    2016-12-01

    Euryhaline teleosts can survive in a broad range of salinity via alteration of the molecular mechanisms in certain osmoregulatory organs, including in the gill and kidney. Among these mechanisms, Na + /K + -ATPase (NKA) plays a crucial role in triggering ion-transporting systems. The switch of NKA isoforms in euryhaline fish gills substantially contributes to salinity adaptation. However, there is little information about switches in the kidneys of euryhaline teleosts. Therefore, the responses of the renal NKA α-isoform protein switch to salinity challenge in euryhaline tilapia (Oreochromis mossambicus) and milkfish (Chanos chanos) with different salinity preferences were examined and compared in this study. Immunohistochemical staining in tilapia kidneys revealed the localization of NKA in renal tubules rather than in the glomeruli, similar to our previous findings in milkfish kidneys. Protein abundance in the renal NKA pan α-subunit-like, α1-, and α3-isoform-like proteins in seawater-acclimated tilapia was significantly higher than in the freshwater group, whereas the α2-isoform-like protein exhibited the opposite pattern of expression. In the milkfish, higher protein abundance in the renal NKA pan α-subunit-like and α1-isoform-like proteins was found in freshwater-acclimated fish, whereas no difference was found in the protein abundance of α2- and α3-isoform-like proteins between groups. These findings suggested that switches for renal NKA α-isoforms, especially the α1-isoform, were involved in renal osmoregulatory mechanisms of euryhaline teleosts. Moreover, differences in regulatory responses of the renal NKA α-subunit to salinity acclimation between tilapia and milkfish revealed that divergent mechanisms for maintaining osmotic balance might be employed by euryhaline teleosts with different salinity preferences. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Comparative feeding ecology of bull sharks (Carcharhinus leucas) in the coastal waters of the southwest Indian Ocean inferred from stable isotope analysis.

    Science.gov (United States)

    Daly, Ryan; Froneman, Pierre W; Smale, Malcolm J

    2013-01-01

    As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas) using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ(13)C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ(13)C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range.

  8. First known feeding trace of the eocene bottom-dwelling fish Notogoneus osculus and its paleontological significance.

    Directory of Open Access Journals (Sweden)

    Anthony J Martin

    Full Text Available BACKGROUND: The Green River Formation (early Eocene, about 42-53 Ma at and near Fossil Butte National Monument in Wyoming, USA, is world famous for its exquisitely preserved freshwater teleost fish in the former Fossil Lake. Nonetheless, trace fossils attributed to fish interacting with the lake bottom are apparently rare, and have not been associated directly with any fish species. Here we interpret the first known feeding and swimming trace fossil of the teleost Notogoneus osculus Cope (Teleostei: Gonorynchidae, which is also represented as a body fossil in the same stratum. METHODOLOGY/PRINCIPAL FINDINGS: A standard description of the trace fossil, identified as Undichna cf. U. simplicatas, was augmented by high-resolution digital images and spatial and mathematical analyses, which allowed for detailed interpretations of the anatomy, swimming mode, feeding behavior, and body size of the tracemaker. Our analysis indicates that the tracemaker was about 45 cm long; used its caudal, anal, and pelvic fins (the posterior half of its body to make the swimming traces; and used a ventrally oriented mouth to make overlapping feeding marks. We hypothesize that the tracemaker was an adult Notogoneus osculus. CONCLUSIONS/SIGNIFICANCE: Our results are the first to link a specific teleost tracemaker with a trace fossil from the Green River Formation, while also interpreting the size and relative age of the tracemaker. The normal feeding and swimming behaviors indicated by the trace fossil indicate temporarily oxygenated benthic conditions in the deepest part of Fossil Lake, counter to most paleoecological interpretations of this deposit. Lastly, our spatial and mathematical analyses significantly update and advance previous approaches to the study of teleost trace fossils.

  9. Stress and serial adult metamorphosis: Multiple roles for the stress axis in socially regulated sex change

    OpenAIRE

    Tessa K Solomon-Lane; Erica J Crespi; Erica J Crespi; Matthew Scott Grober; Matthew Scott Grober

    2013-01-01

    Socially regulated sex change in teleost fishes is a striking example of social status information regulating biological function in the service of reproductive success. The establishment of social dominance in sex changing species is translated into a cascade of changes in behavior, physiology, neuroendocrine function, and morphology that transforms a female into a male, or vice versa. The hypothalamic-pituitary-interrenal axis (HPI, homologous to HP-adrenal axis in mammals and birds) has ...

  10. Biología reproductiva del lenguado Paralichthys orbignyanus: Maduración y potencial reproductivo en ejemplares cultivados y salvajes

    OpenAIRE

    Radonic, M.

    2011-01-01

    Intensive culture of teleost fish introduces changes over the environmental conditions found in their spawning grounds, leading to reproductive dysfunctions. The manipulation of these parameters (photoperiod, temperature) represents a common technique to alter the reproductive rhythms and enhance the spawnings in terms of quality and quantity. Nevertheless, for each species some modifications or adjustments have to be done according to their reproductive strategies. The advantages of manipula...

  11. Stress and serial adult metamorphosis: multiple roles for the stress axis in socially regulated sex change

    OpenAIRE

    Solomon-Lane, Tessa K.; Crespi, Erica J.; Grober, Matthew S.

    2013-01-01

    Socially regulated sex change in teleost fishes is a striking example of social status information regulating biological function in the service of reproductive success. The establishment of social dominance in sex changing species is translated into a cascade of changes in behavior, physiology, neuroendocrine function, and morphology that transforms a female into a male, or vice versa. The hypothalamic-pituitary-interrenal axis (HPI, homologous to HP-adrenal axis in mammals and birds) has be...

  12. Biology of Bony Fish Macrophages

    OpenAIRE

    Hodgkinson, Jordan W.; Grayfer, Leon; Belosevic, Miodrag

    2015-01-01

    Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and ...

  13. ICI 182,780 has agonistic effects and synergizes with estradiol-17 beta in fish liver, but not in testis

    OpenAIRE

    Pinto, Patricia; Singh, Pratap B.; Condeça, João B.; Teodósio, H. R.; Power, Deborah; Canario, Adelino V. M.

    2006-01-01

    Abstract Background ICI 182,780 (ICI) belongs to a new class of antiestrogens developed to be pure estrogen antagonists and, in addition to its therapeutic use, it has been used to knock-out estrogen and estrogen receptor (ER) actions in several mammalian species. In the present study, the effects and mechanism of action of ICI were investigated in the teleost fish, sea bream (Sparus auratus). Methods Three independent in vivo experiments were performed in which mature male tilapia (Oreochrom...

  14. The role of adrenaline as a modulator of cardiac performance in two Antarctic fishes

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Bushnell, Peter G.; Tirsgaard, Bjørn

    2009-01-01

    Abstract: The present work was performed to test the hypothesis that Antarctic teleosts rely mostly on cholinergic inhibition for autonomic modulation of the heart. The effects of adrenaline on the inotropic properties on paced, isometrically contracting muscle strips were examined in two distinct...... to which ventricular tissues responded to adrenaline varied between species, adrenergic stimulation significantly increases myocyte contraction force in this group of fishes. Contraction and relaxation times were not significantly affected by adrenaline concentration while absolute rates of contraction...

  15. Immunity to Fish Rhabdoviruses

    OpenAIRE

    Purcell, Maureen K.; Laing, Kerry J.; Winton, James R.

    2012-01-01

    Members of the family Rhabdoviridae are single-stranded RNA viruses and globally important pathogens of wild and cultured fish and thus relatively well studied in their respective hosts or other model systems. Here, we review the protective immune mechanisms that fish mount in response to rhabdovirus infections. Teleost fish possess the principal components of innate and adaptive immunity found in other vertebrates. Neutralizing antibodies are critical for long-term protection from fish rhabd...

  16. Towards Understanding the Role of Colour Information in Scene Perception using Night Vision Device

    Science.gov (United States)

    2009-06-01

    possessing a visual system much simplified from that of living birds, reptiles, and teleost (bony) fish , which are generally tetrachromatic (Bowmaker...Levkowitz and Herman (1992) speculated that the results might be limited to “ blob ” detection. A possible mediating factor may have been the size and...sharpness of the “ blobs ” used in their task. Mullen (1985) showed that the visual system is much more sensitive to the 7 DSTO-RR-0345 high spatial

  17. Healing of corneal epithelial wounds in marine and freshwater fish.

    Science.gov (United States)

    Ubels, J L; Edelhauser, H F

    The corneal epithelium of a fish is in direct contact with the aquatic environment and is a barrier to movement of ions and water into and through the cornea. This tissue layer is thus important in maintenance of corneal transparency. When the epithelium is wounded, its protective function is lost and corneal transparency remains compromised until the epithelial barrier is re-established. This study was undertaken to investigate the healing response of the fish cornea to epithelial abrasion. Wounds were stained with fluorescein and photographed during healing. Wound areas were measured by planimetry. The cornea of the sculpin, a marine teleost, becomes edematous after wounding and heals at 2.54 to 3.42 mm2/hr. Nonswelling corneas of the elasmobranchs--dogfish shark and skate--heal at 1.29 mm2/hr, respectively. The wounded eye of the rainbow trout, a freshwater teleost, is stressed by the low osmolality of the environment. Severe corneal edema and cataracts develop following epithelial wounding, and the cornea heals at 0.64 mm2/hr. Although the healing rates in teleosts differ from those in mammals, histology shows that the corneal healing mechanism is essentially the same in fish and mammals.

  18. Polyvalent cation receptor proteins (CaRs) are salinity sensors in fish.

    Science.gov (United States)

    Nearing, J; Betka, M; Quinn, S; Hentschel, H; Elger, M; Baum, M; Bai, M; Chattopadyhay, N; Brown, E M; Hebert, S C; Harris, H W

    2002-07-09

    To determine whether calcium polyvalent cation-sensing receptors (CaRs) are salinity sensors in fish, we used a homology-based cloning strategy to isolate a 4.1-kb cDNA encoding a 1,027-aa dogfish shark (Squalus acanthias) kidney CaR. Expression studies in human embryonic kidney cells reveal that shark kidney senses combinations of Ca(2+), Mg(2+), and Na(+) ions at concentrations present in seawater and kidney tubules. Shark kidney is expressed in multiple shark osmoregulatory organs, including specific tubules of the kidney, rectal gland, stomach, intestine, olfactory lamellae, gill, and brain. Reverse transcriptase-PCR amplification using specific primers in two teleost fish, winter flounder (Pleuronectes americanus) and Atlantic salmon (Salmo salar), reveals a similar pattern of CaR tissue expression. Exposure of the lumen of winter flounder urinary bladder to the CaR agonists, Gd(3+) and neomycin, reversibly inhibit volume transport, which is important for euryhaline teleost survival in seawater. Within 24-72 hr after transfer of freshwater-adapted Atlantic salmon to seawater, there are increases in their plasma Ca(2+), Mg(2+), and Na(+) that likely serve as a signal for internal CaRs, i.e., brain, to sense alterations in salinity in the surrounding water. We conclude that CaRs act as salinity sensors in both teleost and elasmobranch fish. Their tissue expression patterns in fish provide insights into CaR functions in terrestrial animals including humans.

  19. Survey sequencing and comparative analysis of the elephant shark (Callorhinchus milii genome.

    Directory of Open Access Journals (Sweden)

    Byrappa Venkatesh

    2007-04-01

    Full Text Available Owing to their phylogenetic position, cartilaginous fishes (sharks, rays, skates, and chimaeras provide a critical reference for our understanding of vertebrate genome evolution. The relatively small genome of the elephant shark, Callorhinchus milii, a chimaera, makes it an attractive model cartilaginous fish genome for whole-genome sequencing and comparative analysis. Here, the authors describe survey sequencing (1.4x coverage and comparative analysis of the elephant shark genome, one of the first cartilaginous fish genomes to be sequenced to this depth. Repetitive sequences, represented mainly by a novel family of short interspersed element-like and long interspersed element-like sequences, account for about 28% of the elephant shark genome. Fragments of approximately 15,000 elephant shark genes reveal specific examples of genes that have been lost differentially during the evolution of tetrapod and teleost fish lineages. Interestingly, the degree of conserved synteny and conserved sequences between the human and elephant shark genomes are higher than that between human and teleost fish genomes. Elephant shark contains putative four Hox clusters indicating that, unlike teleost fish genomes, the elephant shark genome has not experienced an additional whole-genome duplication. These findings underscore the importance of the elephant shark as a critical reference vertebrate genome for comparative analysis of the human and other vertebrate genomes. This study also demonstrates that a survey-sequencing approach can be applied productively for comparative analysis of distantly related vertebrate genomes.

  20. Serotonin Coordinates Responses to Social Stress-What We Can Learn from Fish.

    Science.gov (United States)

    Backström, Tobias; Winberg, Svante

    2017-01-01

    Social interaction is stressful and subordinate individuals are often subjected to chronic stress, which greatly affects both their behavior and physiology. In teleost fish the social position of an individual may have long-term effects, such as effects on migration, age of sexual maturation or even sex. The brain serotonergic system plays a key role in coordinating autonomic, behavioral and neuroendocrine stress responses. Social subordination results in a chronic activation of the brain serotonergic system an effect, which seems to be central in the subordinate phenotype. However, behavioral effects of short-term acute activation of the serotonergic system are less obvious. As in other vertebrates, divergent stress coping styles, often referred to as proactive and reactive, has been described in teleosts. As demonstrated by selective breeding, stress coping styles appear to be partly heritable. However, teleost fish are characterized by plasticity, stress coping style being affected by social experience. Again, the brain serotonergic system appears to play an important role. Studies comparing brain gene expression of fish of different social rank and/or displaying divergent stress coping styles have identified several novel factors that seem important for controlling aggressive behavior and stress coping, e.g., histamine and hypocretin/orexin. These may also interact with brain monoaminergic systems, including serotonin.

  1. Serotonin Coordinates Responses to Social Stress—What We Can Learn from Fish

    Directory of Open Access Journals (Sweden)

    Tobias Backström

    2017-10-01

    Full Text Available Social interaction is stressful and subordinate individuals are often subjected to chronic stress, which greatly affects both their behavior and physiology. In teleost fish the social position of an individual may have long-term effects, such as effects on migration, age of sexual maturation or even sex. The brain serotonergic system plays a key role in coordinating autonomic, behavioral and neuroendocrine stress responses. Social subordination results in a chronic activation of the brain serotonergic system an effect, which seems to be central in the subordinate phenotype. However, behavioral effects of short-term acute activation of the serotonergic system are less obvious. As in other vertebrates, divergent stress coping styles, often referred to as proactive and reactive, has been described in teleosts. As demonstrated by selective breeding, stress coping styles appear to be partly heritable. However, teleost fish are characterized by plasticity, stress coping style being affected by social experience. Again, the brain serotonergic system appears to play an important role. Studies comparing brain gene expression of fish of different social rank and/or displaying divergent stress coping styles have identified several novel factors that seem important for controlling aggressive behavior and stress coping, e.g., histamine and hypocretin/orexin. These may also interact with brain monoaminergic systems, including serotonin.

  2. An updated check list of the ichthyofaunal species assemblage of the Tsitsikamma National Park, South Africa

    Directory of Open Access Journals (Sweden)

    A.D. Wood

    2000-07-01

    Full Text Available This work summarises ichthyological research in the Tsitsikamma National Park (TNP over the past 20 years, and an updated species check list of fishes has been compiled. A total of 202 species of fishes from 84 families has been recorded within the boundaries of the national park. All species which have been included were identified from visual transects, rotenone collections, estuarine surveys, ichthyoplankton surveys, mark/recapture studies and personal observations. The ichthyofauna is a diverse assemblage of chondrichthyans and teleosts, 75 (37.1 of which are components of commercial and recreational fisheries along the east coast. Surveys also indicate that the TNP provides refuge to all life history stages for 17 of the commercial and recreational teleost species. The need for more detailed collections of previously neglected teleost and chondrichthyan groups is recognised. The number of species and diversity demonstrates that the TNP appears not only to afford protection to exploited fish species, but also fulfills one of the basic requirements of Marine Protected Areas@that of conserving biodiversity (of fishes.

  3. Evolutionary origins of taste buds: phylogenetic analysis of purinergic neurotransmission in epithelial chemosensors

    Science.gov (United States)

    Kirino, Masato; Parnes, Jason; Hansen, Anne; Kiyohara, Sadao; Finger, Thomas E.

    2013-01-01

    Taste buds are gustatory endorgans which use an uncommon purinergic signalling system to transmit information to afferent gustatory nerve fibres. In mammals, ATP is a crucial neurotransmitter released by the taste cells to activate the afferent nerve fibres. Taste buds in mammals display a characteristic, highly specific ecto-ATPase (NTPDase2) activity, suggesting a role in inactivation of the neurotransmitter. The purpose of this study was to test whether the presence of markers of purinergic signalling characterize taste buds in anamniote vertebrates and to test whether similar purinergic systems are employed by other exteroceptive chemosensory systems. The species examined include several teleosts, elasmobranchs, lampreys and hagfish, the last of which lacks vertebrate-type taste buds. For comparison, Schreiner organs of hagfish and solitary chemosensory cells (SCCs) of teleosts, both of which are epidermal chemosensory end organs, were also examined because they might be evolutionarily related to taste buds. Ecto-ATPase activity was evident in elongate cells in all fish taste buds, including teleosts, elasmobranchs and lampreys. Neither SCCs nor Schreiner organs show specific ecto-ATPase activity, suggesting that purinergic signalling is not crucial in those systems as it is for taste buds. These findings suggest that the taste system did not originate from SCCs but arose independently in early vertebrates. PMID:23466675

  4. Genome-Wide Identification and Transcriptome-Based Expression Profiling of the Sox Gene Family in the Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Wei, Ling; Yang, Chao; Tao, Wenjing; Wang, Deshou

    2016-02-23

    The Sox transcription factor family is characterized with the presence of a Sry-related high-mobility group (HMG) box and plays important roles in various biological processes in animals, including sex determination and differentiation, and the development of multiple organs. In this study, 27 Sox genes were identified in the genome of the Nile tilapia (Oreochromis niloticus), and were classified into seven groups. The members of each group of the tilapia Sox genes exhibited a relatively conserved exon-intron structure. Comparative analysis showed that the Sox gene family has undergone an expansion in tilapia and other teleost fishes following their whole genome duplication, and group K only exists in teleosts. Transcriptome-based analysis demonstrated that most of the tilapia Sox genes presented stage-specific and/or sex-dimorphic expressions during gonadal development, and six of the group B Sox genes were specifically expressed in the adult brain. Our results provide a better understanding of gene structure and spatio-temporal expression of the Sox gene family in tilapia, and will be useful for further deciphering the roles of the Sox genes during sex determination and gonadal development in teleosts.

  5. Genome-Wide Identification and Transcriptome-Based Expression Profiling of the Sox Gene Family in the Nile Tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Ling Wei

    2016-02-01

    Full Text Available The Sox transcription factor family is characterized with the presence of a Sry-related high-mobility group (HMG box and plays important roles in various biological processes in animals, including sex determination and differentiation, and the development of multiple organs. In this study, 27 Sox genes were identified in the genome of the Nile tilapia (Oreochromis niloticus, and were classified into seven groups. The members of each group of the tilapia Sox genes exhibited a relatively conserved exon-intron structure. Comparative analysis showed that the Sox gene family has undergone an expansion in tilapia and other teleost fishes following their whole genome duplication, and group K only exists in teleosts. Transcriptome-based analysis demonstrated that most of the tilapia Sox genes presented stage-specific and/or sex-dimorphic expressions during gonadal development, and six of the group B Sox genes were specifically expressed in the adult brain. Our results provide a better understanding of gene structure and spatio-temporal expression of the Sox gene family in tilapia, and will be useful for further deciphering the roles of the Sox genes during sex determination and gonadal development in teleosts.

  6. Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens.

    Science.gov (United States)

    Iwanowicz, Luke R; Stafford, James L; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W; Blazer, Vicki S

    2014-09-01

    Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines. Published by Elsevier Ltd.

  7. Stress and sex: does cortisol mediate sex change in fish?

    Science.gov (United States)

    Goikoetxea, Alexander; Todd, Erica V; Gemmell, Neil J

    2017-12-01

    Cortisol is the main glucocorticoid (GC) in fish and the hormone most directly associated with stress. Recent research suggests that this hormone may act as a key factor linking social environmental stimuli and the onset of sex change by initiating a shift in steroidogenesis from estrogens to androgens. For many teleost fish, sex change occurs as a usual part of the life cycle. Changing sex is known to enhance the lifetime reproductive success of these fish and the modifications involved (behavioral, gonadal and morphological) are well studied. However, the exact mechanism behind the transduction of the environmental signals into the molecular cascade that underlies this singular process remains largely unknown. We here synthesize current knowledge regarding the role of cortisol in teleost sex change with a focus on two well-described transformations: temperature-induced masculinization and socially regulated sex change. Three non-mutually exclusive pathways are considered when describing the potential role of cortisol in mediating teleost sex change: cross-talk between GC and androgen pathways, inhibition of aromatase expression and upregulation of amh (the gene encoding anti-Müllerian hormone). We anticipate that understanding the role of cortisol in the initial stages of sex change will further improve our understanding of sex determination and differentiation across vertebrates, and may lead to new tools to control fish sex ratios in aquaculture. © 2017 Society for Reproduction and Fertility.

  8. 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.

    Science.gov (United States)

    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.

  9. A comparative analysis of feeding and trophic level ecology in stingrays (Rajiformes; Myliobatoidei and electric rays (Rajiformes: Torpedinoidei.

    Directory of Open Access Journals (Sweden)

    Ian P Jacobsen

    Full Text Available Standardised diets and trophic level (T L estimates were calculated for 75 ray species from the suborders Myliobatoidei (67 spp. and Torpedinoidei (8 spp.. Decapod crustaceans (31.71 ± 3.92% and teleost fishes (16.45 ± 3.43% made the largest contribution to the standardised diet of the Myliobatoidei. Teleost fishes (37.40 ± 16.09% and polychaete worms (31.96 ± 14.22% were the most prominent prey categories in the standardised diet of the suborder Torpedinoidei. Cluster analysis identified nine major trophic guilds the largest of which were decapod crustaceans (24 species, teleost fishes (11 species and molluscs (11 species. Trophic level estimates for rays ranged from 3.10 for Potamotrygon falkneri to 4.24 for Gymnura australis, Torpedo marmorata and T. nobiliana. Secondary consumers with a T L <4.00 represented 84% of the species examined, with the remaining 12 species (16% classified as tertiary consumers (T L ≥ 4.00. Tertiary consumers included electric rays (Torpedo, 3 spp. and Hypnos, 1 sp., butterfly rays (Gymnura, 4 spp., stingrays (2 spp. and Potamotrygonid stingrays (2 spp.. Feeding strategies were identified as the primary factor of influence with respect to Myliobatoidei and Torpedinoidei T L estimates with inter-family comparisons providing the greatest insight into Myliobatoidei and Torpedinoidei relationships.

  10. Biology of Bony Fish Macrophages

    Directory of Open Access Journals (Sweden)

    Jordan W. Hodgkinson

    2015-11-01

    Full Text Available Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type, and resolution and repair functions (anti-inflammatory/regulatory, M2-type. The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation.

  11. Biology of Bony Fish Macrophages.

    Science.gov (United States)

    Hodgkinson, Jordan W; Grayfer, Leon; Belosevic, Miodrag

    2015-11-30

    Macrophages are found across all vertebrate species, reside in virtually all animal tissues, and play critical roles in host protection and homeostasis. Various mechanisms determine and regulate the highly plastic functional phenotypes of macrophages, including antimicrobial host defenses (pro-inflammatory, M1-type), and resolution and repair functions (anti-inflammatory/regulatory, M2-type). The study of inflammatory macrophages in immune defense of teleosts has garnered much attention, and antimicrobial mechanisms of these cells have been extensively studied in various fish models. Intriguingly, both similarities and differences have been documented for the regulation of lower vertebrate macrophage antimicrobial defenses, as compared to what has been described in mammals. Advances in our understanding of the teleost macrophage M2 phenotypes likewise suggest functional conservation through similar and distinct regulatory strategies, compared to their mammalian counterparts. In this review, we discuss the current understanding of the molecular mechanisms governing teleost macrophage functional heterogeneity, including monopoetic development, classical macrophage inflammatory and antimicrobial responses as well as alternative macrophage polarization towards tissues repair and resolution of inflammation.

  12. Evolutionary origins of taste buds: phylogenetic analysis of purinergic neurotransmission in epithelial chemosensors.

    Science.gov (United States)

    Kirino, Masato; Parnes, Jason; Hansen, Anne; Kiyohara, Sadao; Finger, Thomas E

    2013-03-06

    Taste buds are gustatory endorgans which use an uncommon purinergic signalling system to transmit information to afferent gustatory nerve fibres. In mammals, ATP is a crucial neurotransmitter released by the taste cells to activate the afferent nerve fibres. Taste buds in mammals display a characteristic, highly specific ecto-ATPase (NTPDase2) activity, suggesting a role in inactivation of the neurotransmitter. The purpose of this study was to test whether the presence of markers of purinergic signalling characterize taste buds in anamniote vertebrates and to test whether similar purinergic systems are employed by other exteroceptive chemosensory systems. The species examined include several teleosts, elasmobranchs, lampreys and hagfish, the last of which lacks vertebrate-type taste buds. For comparison, Schreiner organs of hagfish and solitary chemosensory cells (SCCs) of teleosts, both of which are epidermal chemosensory end organs, were also examined because they might be evolutionarily related to taste buds. Ecto-ATPase activity was evident in elongate cells in all fish taste buds, including teleosts, elasmobranchs and lampreys. Neither SCCs nor Schreiner organs show specific ecto-ATPase activity, suggesting that purinergic signalling is not crucial in those systems as it is for taste buds. These findings suggest that the taste system did not originate from SCCs but arose independently in early vertebrates.

  13. The origin and migration of primordial germ cells in sturgeons.

    Directory of Open Access Journals (Sweden)

    Taiju Saito

    Full Text Available Primordial germ cells (PGCs arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts.

  14. The fate of the duplicated androgen receptor in fishes: a late neofunctionalization event?

    Directory of Open Access Journals (Sweden)

    Haendler Bernard

    2008-12-01

    Full Text Available Abstract Background Based on the observation of an increased number of paralogous genes in teleost fishes compared with other vertebrates and on the conserved synteny between duplicated copies, it has been shown that a whole genome duplication (WGD occurred during the evolution of Actinopterygian fish. Comparative phylogenetic dating of this duplication event suggests that it occurred early on, specifically in teleosts. It has been proposed that this event might have facilitated the evolutionary radiation and the phenotypic diversification of the teleost fish, notably by allowing the sub- or neo-functionalization of many duplicated genes. Results In this paper, we studied in a wide range of Actinopterygians the duplication and fate of the androgen receptor (AR, NR3C4, a nuclear receptor known to play a key role in sex-determination in vertebrates. The pattern of AR gene duplication is consistent with an early WGD event: it has been duplicated into two genes AR-A and AR-B after the split of the Acipenseriformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes. Genomic and syntenic analyses in addition to lack of PCR amplification show that one of the duplicated copies, AR-B, was lost in several basal Clupeocephala such as Cypriniformes (including the model species zebrafish, Siluriformes, Characiformes and Salmoniformes. Interestingly, we also found that, in basal teleost fish (Osteoglossiformes and Anguilliformes, the two copies remain very similar, whereas, specifically in Percomorphs, one of the copies, AR-B, has accumulated substitutions in both the ligand binding domain (LBD and the DNA binding domain (DBD. Conclusion The comparison of the mutations present in these divergent AR-B with those known in human to be implicated in complete, partial or mild androgen insensitivity syndrome suggests that the existence of two distinct AR duplicates may be correlated to specific functional differences that may be

  15. Fish genomes provide novel insights into the evolution of vertebrate secretin receptors and their ligand.

    Science.gov (United States)

    Cardoso, João C R; Félix, Rute C; Trindade, Marlene; Power, Deborah M

    2014-12-01

    The secretin receptor (SCTR) is a member of Class 2 subfamily B1 GPCRs and part of the PAC1/VPAC receptor subfamily. This receptor has long been known in mammals but has only recently been identified in other vertebrates including teleosts, from which it was previously considered to be absent. The ligand for SCTR in mammals is secretin (SCT), an important gastrointestinal peptide, which in teleosts has not yet been isolated, or the gene identified. This study revises the evolutionary model previously proposed for the secretin-GPCRs in metazoan by analysing in detail the fishes, the most successful of the extant vertebrates. All the Actinopterygii genomes analysed and the Chondrichthyes and Sarcopterygii fish possess a SCTR gene that shares conserved sequence, structure and synteny with the tetrapod homologue. Phylogenetic clustering and gene environment comparisons revealed that fish and tetrapod SCTR shared a common origin and diverged early from the PAC1/VPAC subfamily group. In teleosts SCTR duplicated as a result of the fish specific whole genome duplication but in all the teleost genomes analysed, with the exception of tilapia (Oreochromis niloticus), one of the duplicates was lost. The function of SCTR in teleosts is unknown but quantitative PCR revealed that in both sea bass (Dicentrarchus labrax) and tilapia (Oreochromis mossambicus) transcript abundance is high in the gastrointestinal tract suggesting it may intervene in similar processes to those in mammals. In contrast, no gene encoding the ligand SCT was identified in the ray-finned fishes (Actinopterygii) although it was present in the coelacanth (lobe finned fish, Sarcopterygii) and in the elephant shark (holocephalian). The genes in linkage with SCT in tetrapods and coelacanth were also identified in ray-finned fishes supporting the idea that it was lost from their genome. At present SCTR remains an orphan receptor in ray-finned fishes and it will be of interest in the future to establish why SCT was

  16. Steroid receptor expression in the fish inner earvaries with sex, social status, and reproductive state

    Directory of Open Access Journals (Sweden)

    Fernald Russell D

    2010-04-01

    Full Text Available Abstract Background Gonadal and stress-related steroid hormones are known to influence auditory function across vertebrates but the cellular and molecular mechanisms responsible for steroid-mediated auditory plasticity at the level of the inner ear remain unknown. The presence of steroid receptors in the ear suggests a direct pathway for hormones to act on the peripheral auditory system, but little is known about which receptors are expressed in the ear or whether their expression levels change with internal physiological state or external social cues. We used qRT-PCR to measure mRNA expression levels of multiple steroid receptor subtypes (estrogen receptors: ERα, ERβa, ERβb; androgen receptors: ARα, ARβ; corticosteroid receptors: GR2, GR1a/b, MR and aromatase in the main hearing organ of the inner ear (saccule in the highly social African cichlid fish Astatotilapia burtoni, and tested whether these receptor levels were correlated with circulating steroid concentrations. Results We show that multiple steroid receptor subtypes are expressed within the main hearing organ of a single vertebrate species, and that expression levels differ between the sexes. We also show that steroid receptor subtype-specific changes in mRNA expression are associated with reproductive phase in females and social status in males. Sex-steroid receptor mRNA levels were negatively correlated with circulating estradiol and androgens in both males and females, suggesting possible ligand down-regulation of receptors in the inner ear. In contrast, saccular changes in corticosteroid receptor mRNA levels were not related to serum cortisol levels. Circulating steroid levels and receptor subtype mRNA levels were not as tightly correlated in males as compared to females, suggesting different regulatory mechanisms between sexes. Conclusions This is the most comprehensive study of sex-, social-, and reproductive-related steroid receptor mRNA expression in the peripheral

  17. Diet and condition of mesopredators on coral reefs in relation to shark abundance.

    Science.gov (United States)

    Barley, Shanta C; Meekan, Mark G; Meeuwig, Jessica J

    2017-01-01

    Reef sharks may influence the foraging behaviour of mesopredatory teleosts on coral reefs via both risk effects and competitive exclusion. We used a "natural experiment" to test the hypothesis that the loss of sharks on coral reefs can influence the diet and body condition of mesopredatory fishes by comparing two remote, atoll-like reef systems, the Rowley Shoals and the Scott Reefs, in northwestern Australia. The Rowley Shoals are a marine reserve where sharks are abundant, whereas at the Scott Reefs numbers of sharks have been reduced by centuries of targeted fishing. On reefs where sharks were rare, the gut contents of five species of mesopredatory teleosts largely contained fish while on reefs with abundant sharks, the same mesopredatory species consumed a larger proportion of benthic invertebrates. These measures of diet were correlated with changes in body condition, such that the condition of mesopredatory teleosts was significantly poorer on reefs with higher shark abundance. Condition was defined as body weight, height and width for a given length and also estimated via several indices of condition. Due to the nature of natural experiments, alternative explanations cannot be discounted. However, the results were consistent with the hypothesis that loss of sharks may influence the diet and condition of mesopredators and by association, their fecundity and trophic role. Regardless of the mechanism (risk effects, competitive release, or other), our findings suggest that overfishing of sharks has the potential to trigger trophic cascades on coral reefs and that further declines in shark populations globally should be prevented to protect ecosystem health.

  18. Gonadotropin-dependent oocyte maturational competence requires activation of the protein kinase A pathway and synthesis of RNA and protein in ovarian follicles of Nibe, Nibea mitsukurii (Teleostei, Sciaenidae)

    Science.gov (United States)

    Yoshizaki, G.; Shusa, M.; Takeuchi, T.; Patino, R.

    2002-01-01

    Luteinizing hormone- (LH)-dependent ovarian follicle maturation has been recently described in two stages for teleost fishes. The oocyte's ability to respond to the steroidal maturation-inducing hormone (MIH), also known as oocyte maturational competence (OMC), is acquired during the first stage; whereas the MIH-dependent resumption of meiosis occurs during the second stage. However, studies directly addressing OMC have been performed with a limited number of species and therefore the general relevance of the two-stage model and its mechanisms remain uncertain. In this study, we examined the hormonal regulation of OMC and its basic transduction mechanisms in ovarian follicles of the sciaenid teleost, Nibe (Nibea mitsukurii). Exposure to MIH [17,20??-dihydroxy-4-pregnen-3-one or 17,20??,21-trihydroxy-4-pregnen-3-one] stimulated germinal vesicle breakdown (index of meiotic resumption) in full-grown follicles primed with human chorionic gonadotropin (HCG, an LH-like gonadotropin) but not in those pre-cultured in plain incubation medium. The induction of OMC by HCG was mimicked by protein kinase A (PKA) activators (forskolin and dibutyryl cyclic AMP), and blocked by specific inhibitors of PKA (H89 and H8) as well as inhibitors of RNA (actinomycin D) and protein (cycloheximide) synthesis. Forskolin-induced OMC was also inhibited by actinomycin D and cycloheximide. A strong activator of protein kinase C, PMA, inhibited HCG-dependent OMC. In conclusion, OMC in Nibe ovarian follicles is gonadotropin-dependent and requires activation of the PKA pathway followed by gene transcription and translation events. These observations are consistent with the two-stage model of ovarian follicle maturation proposed for other teleosts, and suggest that Nibe can be used as new model species for mechanistic studies of ovarian follicle differentiation and maturation in fishes.

  19. Suction generation in white-spotted bamboo sharks Chiloscyllium plagiosum.

    Science.gov (United States)

    Wilga, Cheryl D; Sanford, Christopher P

    2008-10-01

    After the divergence of chondrichthyans and teleostomes, the structure of the feeding apparatus also diverged leading to alterations in the suction mechanism. In this study we investigated the mechanism for suction generation during feeding in white-spotted bamboo sharks, Chiloscyllium plagiosum and compared it with that in teleosts. The internal movement of cranial elements and pressure in the buccal, hyoid and pharyngeal cavities that are directly responsible for suction generation was quantified using sonomicrometry and pressure transducers. Backward stepwise multiple linear regressions were used to explore the relationship between expansion and pressure, accounting for 60-96% of the variation in pressure among capture events. The progression of anterior to posterior expansion in the buccal, hyoid and pharyngeal cavities is accompanied by the sequential onset of subambient pressure in these cavities as prey is drawn into the mouth. Gape opening triggers the onset of subambient pressure in the oropharyngeal cavities. Peak gape area coincides with peak subambient buccal pressure. Increased velocity of hyoid area expansion is primarily responsible for generating peak subambient pressure in the buccal and hyoid regions. Pharyngeal expansion appears to function as a sink to receive water influx from the mouth, much like that of compensatory suction in bidirectional aquatic feeders. Interestingly, C. plagiosum generates large suction pressures while paradoxically compressing the buccal cavity laterally, delaying the time to peak pressure. This represents a fundamental difference from the mechanism used to generate suction in teleost fishes. Interestingly, pressure in the three cavities peaks in the posterior to anterior direction. The complex shape changes that the buccal cavity undergoes indicate that, as in teleosts, unsteady flow predominates during suction feeding. Several kinematic variables function together, with great variation over long gape cycles to

  20. Evolutionary plasticity of habenular asymmetry with a conserved efferent connectivity pattern.

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    Aldo Villalón

    Full Text Available The vertebrate habenulae (Hb is an evolutionary conserved dorsal diencephalic nuclear complex that relays information from limbic and striatal forebrain regions to the ventral midbrain. One key feature of this bilateral nucleus is the presence of left-right differences in size, cytoarchitecture, connectivity, neurochemistry and/or gene expression. In teleosts, habenular asymmetry has been associated with preferential innervation of left-right habenular efferents into dorso-ventral domains of the midbrain interpeduncular nucleus (IPN. However, the degree of conservation of this trait and its relation to the structural asymmetries of the Hb are currently unknown. To address these questions, we performed the first systematic comparative analysis of structural and connectional asymmetries of the Hb in teleosts. We found striking inter-species variability in the overall shape and cytoarchitecture of the Hb, and in the frequency, strength and to a lesser degree, laterality of habenular volume at the population level. Directional asymmetry of the Hb was either to the left in D. rerio, E. bicolor, O. latipes, P. reticulata, B. splendens, or to the right in F. gardneri females. In contrast, asymmetry was absent in P. scalare and F. gardneri males at the population level, although in these species the Hb displayed volumetric asymmetries at the individual level. Inter-species variability was more pronounced across orders than within a single order, and coexisted with an overall conserved laterotopic representation of left-right habenular efferents into dorso-ventral domains of the IPN. These results suggest that the circuit design involving the Hb of teleosts promotes structural flexibility depending on developmental, cognitive and/or behavioural pressures, without affecting the main midbrain connectivity output, thus unveiling a key conserved role of this connectivity trait in the function of the circuit. We propose that ontogenic plasticity in habenular

  1. Diet and condition of mesopredators on coral reefs in relation to shark abundance.

    Directory of Open Access Journals (Sweden)

    Shanta C Barley

    Full Text Available Reef sharks may influence the foraging behaviour of mesopredatory teleosts on coral reefs via both risk effects and competitive exclusion. We used a "natural experiment" to test the hypothesis that the loss of sharks on coral reefs can influence the diet and body condition of mesopredatory fishes by comparing two remote, atoll-like reef systems, the Rowley Shoals and the Scott Reefs, in northwestern Australia. The Rowley Shoals are a marine reserve where sharks are abundant, whereas at the Scott Reefs numbers of sharks have been reduced by centuries of targeted fishing. On reefs where sharks were rare, the gut contents of five species of mesopredatory teleosts largely contained fish while on reefs with abundant sharks, the same mesopredatory species consumed a larger proportion of benthic invertebrates. These measures of diet were correlated with changes in body condition, such that the condition of mesopredatory teleosts was significantly poorer on reefs with higher shark abundance. Condition was defined as body weight, height and width for a given length and also estimated via several indices of condition. Due to the nature of natural experiments, alternative explanations cannot be discounted. However, the results were consistent with the hypothesis that loss of sharks may influence the diet and condition of mesopredators and by association, their fecundity and trophic role. Regardless of the mechanism (risk effects, competitive release, or other, our findings suggest that overfishing of sharks has the potential to trigger trophic cascades on coral reefs and that further declines in shark populations globally should be prevented to protect ecosystem health.

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

    Science.gov (United States)

    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

  3. Copper toxicity in the spiny dogfish (Squalus acanthias): urea loss contributes to the osmoregulatory disturbance.

    Science.gov (United States)

    De Boeck, G; Hattink, J; Franklin, N M; Bucking, C P; Wood, S; Walsh, P J; Wood, C M

    2007-08-30

    Previous research showed that the spiny dogfish, Squalus acanthias, is much more sensitive to silver exposure than typical marine teleosts. The aim of the present study was to investigate if spiny dogfish were equally sensitive to copper exposure and whether the toxic mechanisms were the same. We exposed cannulated and non-cannulated spiny dogfish to measured concentrations of Cu (nominally 0, 500, 1000 and 1500 microg L(-1) Cu) for 72-96 h. All Cu exposures induced acidosis and lactate accumulation of either a temporary (500 microg L(-1)) or more persistent nature (1000 and 1500 microg L(-1)). At the two highest Cu concentrations, gill Na(+)/K(+)-ATPase activities were reduced by 45% (1000 microg L(-1)) and 62% (1500 microg L(-1)), and plasma Na(+) and Cl(-) concentrations increased by approximately 50 mM each. At the same time urea excretion doubled and plasma urea dropped by approximately 100 mM. Together with plasma urea, plasma TMAO levels dropped proportionally, indicating that the general impermeability of the gills was compromised. Overall plasma osmolarity did not change. Cu accumulation was limited with significant increases in plasma Cu and elevated gill and kidney Cu burdens at 1000 and 1500 microg L(-1). We conclude that Cu, like Ag, exerts toxic effect on Na(+)/K(+)-ATPase activities in the shark similar to those of teleosts, but there is an additional toxic action on elasmobranch urea retention capacities. With a 96 h LC(50) in the 800-1000 microg L(-1) range, overall sensitivity of spiny dogfish for Cu is, in contrast with its sensitivity to Ag, only slightly lower than in typical marine teleosts.

  4. Escape manoeuvres in the spiny dogfish (Squalus acanthias).

    Science.gov (United States)

    Domenici, Paolo; Standen, Emily M; Levine, Robert P

    2004-06-01

    The locomotor performance of dogfish during escape responses was observed by means of high-speed video. Dogfish show C-type escape responses that are comparable with those shown previously in teleosts. Dogfish show high variability of turning rates of the anterior part of the body (head to centre of mass), i.e. with peak values from 434 to 1023 deg. s(-1). We suggest that this variability may be due to the presence of two types of escape manoeuvres, i.e. responses with high and low turning rates, as previously found in a teleost species. Fast responses (i.e. with high maximum turning rates, ranging between 766 and 1023 deg. s(-1)) showed significantly higher locomotor performance than slow responses (i.e. with low maximum turning rates, ranging between 434 and 593 deg. s(-1)) in terms of distance covered, speed and acceleration, although no differences were found in the turning radius of the centre of mass during the escape manoeuvres. The existence of two types of escape responses would have implications in terms of both neural control and muscular activation patterns. When compared with literature data for the locomotor performance of bony fishes, dogfish showed relatively low speed and acceleration, comparable turning rates and a turning radius that is in the low part of the range when compared with teleosts, indicating relatively high manoeuvrability. The locomotor performance observed in dogfish is consistent with their morphological characteristics: (1) low locomotor performance associated with low thrust developed by their relatively small posterior depth of section and (2) relatively high manoeuvrability associated with their high flexibility.

  5. Sensitivity of the spiny dogfish (Squalus acanthias) to waterborne silver exposure.

    Science.gov (United States)

    De Boeck, G; Grosell, M; Wood, C

    2001-10-01

    The physiological effects of waterborne silver exposure (added as AgNO(3)) on spiny dogfish, Squalus acanthias, were evaluated at 30, 200 and 685 microg silver per l in 30 per thousand seawater. These concentrations cover the toxic range observed for freshwater teleosts, where silver is extremely toxic, to seawater teleosts which tolerate higher silver concentrations. However, these levels are considerably higher than those that occur in the normal environment. At 685 microg l(-1), dogfish died within 24 h. Causes of death were respiratory as well as osmoregulatory failure. Arterial P(a)O(2) rapidly declined below 20 Torr, and blood acidosis (both respiratory and metabolic) occurred. Urea excretion increased dramatically and plasma urea dropped from 340 to 225 mM. There were pronounced increases in plasma Na(+), Cl(-), and Mg(2+), indicative of ionoregulatory failure due to increased diffusive permeability as well as inhibited NaCl excretion. At 200 microg l(-1), fish died between 24 and 72 h of silver exposure. The same physiological events occurred with a small time delay. At 30 microg l(-1), effects were much less severe, although slight mortality (12.5%) still occurred. Respiratory alkalosis occurred, together with moderate elevations in plasma Na(+) and Cl(-) levels. Silver accumulated to the highest concentrations on gills, with only low levels in the intestine, in accord with the virtual absence of drinking. Na(+)/K(+)-ATP-ase activities of gill and rectal gland tissue were impaired at the highest silver concentration. Normal gill function was impaired due to swelling and fusion of lamellae, lamellar aneurism and lifting of the lamellar epithelium. Our results clearly indicate that this elasmobranch is much more sensitive (about 10-fold) to silver than marine teleosts, with silver's toxic action exerted on the gill rather than on the intestine, in contrast to the latter.

  6. Genome specific PPARαB duplicates in salmonids and insights into estrogenic regulation in brown trout.

    Science.gov (United States)

    Madureira, Tânia Vieira; Pinheiro, Ivone; de Paula Freire, Rafaelle; Rocha, Eduardo; Castro, Luis Filipe; Urbatzka, Ralph

    2017-06-01

    Peroxisome proliferator-activated receptors (PPARs) are key regulators of many processes in vertebrates, such as carbohydrate and lipid metabolism. PPARα, a member of the PPAR nuclear receptor gene subfamily (NR1C1), is involved in fatty acid metabolism, namely in peroxisomal β-oxidation. Two gene paralogues, pparαA and pparαB, were described in several teleost species with their origin dating back to the teleost-specific genome duplication (3R). Given the additional salmonid-specific genome duplication (4R), four genes could be theoretically anticipated for this gene subfamily. In this work, we examined the pparα gene repertoire in brown trout, Salmo trutta f. fario. Data disclosed two pparα-like sequences in brown trout. Phylogenetic analyses further revealed that the isolated genes are most likely genome pparαB duplicates, pparαBa and pparαBb, while pparαA is apparently absent in salmonids. Both genes showed a ubiquitous mRNA expression across a panel of 11 different organs. In vitro exposed primary brown trout hepatocytes strongly suggest that pparα gene paralogues are differently regulated by ethinylestradiol (EE2). PparαBb mRNA expression significantly decreased with dosage, reaching significance after exposure to 50μM EE2, while pparαBa mRNA increased, significant at 1μM EE2. The present data enhances the understanding of pparα function and evolution in teleost, and reinforces the evidence of a potential crosstalk between estrogenic and pparα signaling pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Troponin T isoform expression is modulated during Atlantic Halibut metamorphosis

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    Llewellyn Lynda

    2007-06-01

    Full Text Available Abstract Background Flatfish metamorphosis is a thyroid hormone (TH driven process which leads to a dramatic change from a symmetrical larva to an asymmetrical juvenile. The effect of THs on muscle and in particular muscle sarcomer protein genes is largely unexplored in fish. The change in Troponin T (TnT, a pivotal protein in the assembly of skeletal muscles sarcomeres and a modulator of calcium driven muscle contraction, during flatfish metamophosis is studied. Results In the present study five cDNAs for halibut TnT genes were cloned; three were splice variants arising from a single fast TnT (fTnT gene; a fourth encoded a novel teleost specific fTnT-like cDNA (AfTnT expressed exclusively in slow muscle and the fifth encoded the teleost specific sTnT2. THs modified the expression of halibut fTnT isoforms which changed from predominantly basic to acidic isoforms during natural and T4 induced metamorphosis. In contrast, expression of red muscle specific genes, AfTnT and sTnT2, did not change during natural metamorphosis or after T4 treatment. Prior to and after metamorphosis no change in the dorso-ventral symmetry or temporal-spatial expression pattern of TnT genes and muscle fibre organization occurred in halibut musculature. Conclusion Muscle organisation in halibut remains symmetrical even after metamorphosis suggesting TH driven changes are associated with molecular adaptations. We hypothesize that species specific differences in TnT gene expression in teleosts underlies different larval muscle developmental programs which better adapts them to the specific ecological constraints.

  8. High abundance androgen receptor in goldfish brain: characteristics and seasonal changes

    International Nuclear Information System (INIS)

    Pasmanik, M.; Callard, G.V.

    1988-01-01

    Testosterone (T) exerts its actions in brain directly via androgen receptors or, after aromatization to estradiol, via estrogen receptors. Brain aromatase activity in teleost fish is 100-1000 times greater than in mammals and would be expected to significantly reduce the quantity of androgen available for receptor binding. Experiments were carried out on the goldfish Carassius auratus to determine if androgen receptors are present in teleost brain and whether their physicochemical properties reflect elevated aromatase. Cytosolic and nuclear extracts were assayed with the use of [ 3 H]T and charcoal, Sephadex LH-20, or DNA-cellulose chromatography to separate bound and free steroids. Binding activity was saturable and had an equally high affinity for T and 5 alpha-dihydrotestosterone. Although mibolerone was a relatively weak competitor, the putative teleost androgen 11-ketotestosterone, methyltrienolone (R1881), estradiol, progesterone, and cortisol were poor ligands. Characteristics that distinguish this receptor from a steroid-binding protein in goldfish serum are the presence of binding activity in both nuclear and cytosolic extracts, a low rate of ligand-receptor dissociation, electrophoretic mobility, sedimentation properties in low vs. high salt, and tissue distribution. DNA cellulose-adhering and nonadhering forms were detected, but these did not differ in other variables measured. Although goldfish androgen receptors resembled those of mammals in all important physicochemical characteristics, they were unusually abundant compared to levels in rat brain, but comparable to levels in prostate and other male sex hormone target organs. Moreover, there were seasonal variations in total receptors, with a peak at spawning (April) 4- to 5-fold higher than values in reproductively inactive fish

  9. Molecular characterization of Kiss2 receptor and in vitro effects of Kiss2 on reproduction-related gene expression in the hypothalamus of half-smooth tongue sole (Cynoglossus semilaevis).

    Science.gov (United States)

    Wang, Bin; Liu, Quan; Liu, Xuezhou; Xu, Yongjiang; Shi, Bao

    2017-08-01

    Kisspeptin (Kiss) and its receptor, KissR (previously known as GPR54), play a critical role in the control of reproduction and puberty onset in mammals. Additionally, a number of studies have provided evidence of the existence of multiple Kiss/KissR systems in teleosts, but the physiological relevance and functions of these kisspeptin forms (Kiss1 and Kiss2) still remain to be investigated. To this end, we examined the direct actions of Kiss2 on hypothalamic functions in the half-smooth tongue sole (Cynoglossus semilaevis), a representative species of the order Pleuronectiformes. As a first step, the full-length cDNA for kiss2r was identified and kiss2r transcripts were shown to be widely expressed in various tissues, notably in the brain of tongue sole. Then, the effects of Kiss2 decapeptide on reproduction-related gene expression were evaluated using a primary hypothalamus culture system. Our results showed that neither gnrh2 nor gnrh3 mRNA levels were altered by Kiss2. However, Kiss2 significantly increased the amounts of gnih and kiss2 mRNAs. In contrast, Kiss2 elicited an evident inhibitory effect on both gnihr and kiss2r mRNA levels. To the best of our knowledge, this is the first description of a direct and differential regulation of reproduction-related gene expression by Kiss2 at the hypothalamus level of a teleost fish. Overall, this study provides novel information on the role of Kiss2/Kiss2R system in the reproductive function of teleosts. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Plasticidade trófica em peixes de água doce Trophic plasticity in freshwater fishes

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    Angelo Antonio Agostinho

    2001-05-01

    Full Text Available Esta revisão apresenta uma síntese a respeito da plasticidade alimentar em teleósteos de água doce em relação às variações espaço-temporais, ontogenéticas, individuais e comportamentais. A ocorrência de dieta flexível é uma característica marcante da ictiofauna fluvial tropical, onde a maioria das espécies pode mudar de um alimento para outro tão logo ocorram oscilações na abundância relativa do recurso alimentar em uso, motivadas por alterações ambientais espaço-temporais. Quase todas as espécies mudam troficamente durante a ontogenia, e em muitas populações, os indivíduos podem apresentar preferências alimentares ou fazer uso de táticas alimentares distintas, conduzindo a um forrageamento intra-específico diferenciado. Essas considerações evidenciam dificuldades que podem ser encontradas no estabelecimento de padrões alimentares específicos fidedignos para as espécies de teleósteosA synthesis on the feeding flexibility in freshwater teleosts concerning seasonal, spatial, ontogenetic, individual and behavioral variation of freshwater teleosts is provided. The occurrence of a flexible diet is a striking aspect of tropical riverine ichthyofauna where most species may switch from a food item to another as soon as the relative abundance of the feeding resource in use oscillates, motivated by seasonal and spatial environmental alterations. There is a trophical change in almost all species during ontogeny, whereas in most populations, individuals may show feeding preferences or make use of distinct feeding tactics that lead towards a differentiated intraspecific foraging. These considerations highlight the difficulty on setting up reliable specific species feeding patterns in tropical teleosts

  11. Whole-genome single-nucleotide polymorphism (SNP marker discovery and association analysis with the eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA content in Larimichthys crocea

    Directory of Open Access Journals (Sweden)

    Shijun Xiao

    2016-12-01

    Full Text Available Whole-genome single-nucleotide polymorphism (SNP markers are valuable genetic resources for the association and conservation studies. Genome-wide SNP development in many teleost species are still challenging because of the genome complexity and the cost of re-sequencing. Genotyping-By-Sequencing (GBS provided an efficient reduced representative method to squeeze cost for SNP detection; however, most of recent GBS applications were reported on plant organisms. In this work, we used an EcoRI-NlaIII based GBS protocol to teleost large yellow croaker, an important commercial fish in China and East-Asia, and reported the first whole-genome SNP development for the species. 69,845 high quality SNP markers that evenly distributed along genome were detected in at least 80% of 500 individuals. Nearly 95% randomly selected genotypes were successfully validated by Sequenom MassARRAY assay. The association studies with the muscle eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA content discovered 39 significant SNP markers, contributing as high up to ∼63% genetic variance that explained by all markers. Functional genes that involved in fat digestion and absorption pathway were identified, such as APOB, CRAT and OSBPL10. Notably, PPT2 Gene, previously identified in the association study of the plasma n-3 and n-6 polyunsaturated fatty acid level in human, was re-discovered in large yellow croaker. Our study verified that EcoRI-NlaIII based GBS could produce quality SNP markers in a cost-efficient manner in teleost genome. The developed SNP markers and the EPA and DHA associated SNP loci provided invaluable resources for the population structure, conservation genetics and genomic selection of large yellow croaker and other fish organisms.

  12. Proteomic analysis of rainbow trout (Oncorhynchus mykiss) intestinal epithelia: physiological acclimation to short-term starvation.

    Science.gov (United States)

    Baumgarner, Bradley L; Bharadwaj, Anant S; Inerowicz, Dorota; Goodman, Angela S; Brown, Paul B

    2013-03-01

    The intestinal epithelia form the first line of defense against harmful agents in the gut lumen of most monogastric vertebrates, including teleost fishes. Previous investigations into the effect of starvation on the intestinal epithelia of teleost fishes have focused primarily on changes in morphological characteristics and targeted molecular analysis of specific enzymes. The goal of this study was to use a comprehensive approach to help reveal how the intestinal epithelia of carnivorous teleost fishes acclimate to short-term nutrient deprivation. We utilized two-dimensional gel electrophoresis (2-DE) to conduct the proteomic analysis of the mucosal and epithelial layer of the anterior gut intestinal tract (GIT) from satiation fed vs. 4 week starved rainbow trout (Oncorhynchus mykiss). A total of 40 proteins were determined to be differentially expressed and were subsequently picked for in-gel trypsin digestion. Peptide mass fingerprint analysis was conducted using matrix assisted laser desorption time-of-flight/time-of-flight. Nine of the 11 positively identified proteins were directly related to innate immunity. The expression of α-1 proteinase inhibitor decreased in starved vs. fed fish. Also, the concentration of one leukocyte elastase inhibitor (LEI) isomer decreased in starved fish, though the concentration of another LEI isomer increased in due to starvation. In addition, starvation promoted an increased concentration of the important xenobiotic-transporter p-glycoprotein. Finally, starvation resulted in a significant increase in type II keratin E2. Overall, our results indicate that starvation promoted a reduced capacity to inhibit enzymatic stress but increased xenobiotic resistance and paracellular permeability of epithelial cells in the anterior intestine of rainbow trout. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. A second corticotropin-releasing hormone gene (CRH2) is conserved across vertebrate classes and expressed in the hindbrain of a basal neopterygian fish, the spotted gar (Lepisosteus oculatus).

    Science.gov (United States)

    Grone, Brian P; Maruska, Karen P

    2015-05-01

    To investigate the origins of the vertebrate stress-response system, we searched sequenced vertebrate genomes for genes resembling corticotropin-releasing hormone (CRH). We found that vertebrate genomes possess, in addition to CRH, another gene that resembles CRH in sequence and syntenic environment. This paralogous gene was previously identified only in the elephant shark (a holocephalan), but we find it also in marsupials, monotremes, lizards, turtles, birds, and fishes. We examined the relationship of this second vertebrate CRH gene, which we name CRH2, to CRH1 (previously known as CRH) and urocortin1/urotensin1 (UCN1/UTS1) in primitive fishes, teleosts, and tetrapods. The paralogs CRH1 and CRH2 likely evolved via duplication of CRH during a whole-genome duplication early in the vertebrate lineage. CRH2 was subsequently lost in both teleost fishes and eutherian mammals but retained in other lineages. To determine where CRH2 is expressed relative to CRH1 and UTS1, we used in situ hybridization on brain tissue from spotted gar (Lepisosteus oculatus), a neopterygian fish closely related to teleosts. In situ hybridization revealed widespread distribution of both crh1 and uts1 in the brain. Expression of crh2 was restricted to the putative secondary gustatory/secondary visceral nucleus, which also expressed calcitonin-related polypeptide alpha (calca), a marker of parabrachial nucleus in mammals. Thus, the evolutionary history of CRH2 includes restricted expression in the brain, sequence changes, and gene loss, likely reflecting release of selective constraints following whole-genome duplication. The discovery of CRH2 opens many new possibilities for understanding the diverse functions of the CRH family of peptides across vertebrates. © 2015 Wiley Periodicals, Inc.

  14. Evolution of the vertebrate Pax4/6 class of genes with focus on its novel member, the Pax10 gene.

    Science.gov (United States)

    Feiner, Nathalie; Meyer, Axel; Kuraku, Shigehiro

    2014-06-19

    The members of the paired box (Pax) family regulate key developmental pathways in many metazoans as tissue-specific transcription factors. Vertebrate genomes typically possess nine Pax genes (Pax1-9), which are derived from four proto-Pax genes in the vertebrate ancestor that were later expanded through the so-called two-round (2R) whole-genome duplication. A recent study proposed that pax6a genes of a subset of teleost fishes (namely, acanthopterygians) are remnants of a paralog generated in the 2R genome duplication, to be renamed pax6.3, and reported one more group of vertebrate Pax genes (Pax6.2), most closely related to the Pax4/6 class. We propose to designate this new member Pax10 instead and reconstruct the evolutionary history of the Pax4/6/10 class with solid phylogenetic evidence. Our synteny analysis showed that Pax4, -6, and -10 originated in the 2R genome duplications early in vertebrate evolution. The phylogenetic analyses of relationships between teleost pax6a and other Pax4, -6, and -10 genes, however, do not support the proposed hypothesis of an ancient origin of the acanthopterygian pax6a genes in the 2R genome duplication. Instead, we confirmed the traditional scenario that the acanthopterygian pax6a is derived from the more recent teleost-specific genome duplication. Notably, Pax6 is present in all vertebrates surveyed to date, whereas Pax4 and -10 were lost multiple times in independent vertebrate lineages, likely because of their restricted expression patterns: Among Pax6-positive domains, Pax10 has retained expression in the adult retina alone, which we documented through in situ hybridization and quantitative reverse transcription polymerase chain reaction experiments on zebrafish, Xenopus, and anole lizard. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  15. Evolutionary history of glucose-6-phosphatase encoding genes in vertebrate lineages: towards a better understanding of the functions of multiple duplicates.

    Science.gov (United States)

    Marandel, Lucie; Panserat, Stéphane; Plagnes-Juan, Elisabeth; Arbenoits, Eva; Soengas, José Luis; Bobe, Julien

    2017-05-02

    Glucose-6-phosphate (G6pc) is a key enzyme involved in the regulation of the glucose homeostasis. The present study aims at revisiting and clarifying the evolutionary history of g6pc genes in vertebrates. g6pc duplications happened by successive rounds of whole genome duplication that occurred during vertebrate evolution. g6pc duplicated before or around Osteichthyes/Chondrichthyes radiation, giving rise to g6pca and g6pcb as a consequence of the second vertebrate whole genome duplication. g6pca was lost after this duplication in Sarcopterygii whereas both g6pca and g6pcb then duplicated as a consequence of the teleost-specific whole genome duplication. One g6pca duplicate was lost after this duplication in teleosts. Similarly one g6pcb2 duplicate was lost at least in the ancestor of percomorpha. The analysis of the evolution of spatial expression patterns of g6pc genes in vertebrates showed that all g6pc were mainly expressed in intestine and liver whereas teleost-specific g6pcb2 genes were mainly and surprisingly expressed in brain and heart. g6pcb2b, one gene previously hypothesised to be involved in the glucose intolerant phenotype in trout, was unexpectedly up-regulated (as it was in liver) by carbohydrates in trout telencephalon without showing significant changes in other brain regions. This up-regulation is in striking contrast with expected glucosensing mechanisms suggesting that its positive response to glucose relates to specific unknown processes in this brain area. Our results suggested that the fixation and the divergence of g6pc duplicated genes during vertebrates' evolution may lead to adaptive novelty and probably to the emergence of novel phenotypes related to glucose homeostasis.

  16. Evolutionary growth process of highly conserved sequences in vertebrate genomes.

    Science.gov (United States)

    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.

  17. Functions of two distinct prolactin-releasing peptides evolved from a common ancestral gene

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    Tetsuya eTachibana

    2014-11-01

    Full Text Available Prolactin-releasing peptide (PrRP is one of the RF-amide peptides and was originally identified in the bovine hypothalamus as a stimulator of prolactin (PRL release. Independently, another RF-amide peptide was found in Japanese crucian carp and named Carassius RFa (C-RFa, which shows high homology to PrRP and stimulates PRL secretion in teleost fish. Therefore, C-RFa has been recognized as fish PrRP. However, recent work has revealed that PrRP and C-RFa in non-mammalian vertebrates are encoded by separate genes originated through duplication of an ancestral gene. Indeed, both PrRP and C-RFa are suggested to exist in teleost, amphibian, reptile, and avian species. Therefore, we propose that non-mammalian PrRP (C-RFa be renamed PrRP2. Despite a common evolutionary origin, PrRP2 appears to be a physiological regulator of PRL, whereas this is not a consistent role for PrRP itself. Further work revealed that the biological functions of PrRP and PrRP2 are not limited solely to PRL release, because they are also neuromodulators of several hypothalamus-pituitary axes and are involved in some brain circuits related to the regulation of food intake, stress, and cardiovascular functions. However, these actions appear to be different among vertebrates. For example, central injection of PrRP inhibits feeding behavior in rodents and teleosts while it stimulates it in chicks. Therefore, both PrRP and PrRP2 have acquired diverse actions through evolution. In this review, we integrate the burgeoning information of structures, expression profiles, and multiple biological actions of PrRP in higher vertebrates, as well as those of PrRP2 in non-mammals.

  18. The feeding habits of the eyespot skate Atlantoraja cyclophora (Elasmobranchii: Rajiformes in southeastern Brazil

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    Alessandra da Fonseca Viana

    2014-04-01

    Full Text Available The stomach contents of the eyespot skate, Atlantoraja cyclophora (Regan, 1903, were examined with the goal to provide information about the diet of the species. Samples were collected off the southern coast of Rio de Janeiro, Brazil, near Ilha Grande, between January 2006 and August 2007, at a depth of about 60 m. The diet was analyzed by sex, maturity stages and quarterly to verify differences in the importance of food items. The latter were analyzed by: frequency of occurrence, percentage of weight and in the Alimentary Index. The trophic niche width was determined to assess the degree of specialization in the diet. Additionally, the degree of dietary overlap between males and females; juveniles and adults and periods of the year were defined. A total of 59 individuals of A. cyclophora were captured. Females and adults were more abundant. The quarters with the highest concentrations of individuals were in the summer of the Southern Hemisphere: Jan-Feb-Mar 06 and Jan-Feb-Mar 07. Prey items were classed into five main groups: Crustacea, Teleosts, Elasmobranchs, Polychaeta, and Nematoda. The most important groups in the diet of the eyespot skate were Crustacea and Teleosts. The crab Achelous spinicarpus (Stimpson, 1871 was the most important item. The value of the niche width was small, indicating that a few food items are important. The comparison of the diet between males and females and juveniles and adults indicates a significant overlap between the sexes and stages of maturity; and according to quarters, the importance of prey groups differed (crustaceans were more important in the quarters of the summer and teleost in Jul-Aug-Sep and Oct-Nov-Dec 06, indicating seasonal differences in diet composition. Three groups with similar diets were formed in the cluster analysis: (Jan-Feb-Mar 06 and 07; (Apr-May-Jun 06 and Jul-Aug-Sep 07; (Jul-Aug-Sep 06 and Oct-Nov-Dec 06.

  19. Genome Wide Identification, Phylogeny, and Expression of Aquaporin Genes in Common Carp (Cyprinus carpio.

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    Chuanju Dong

    Full Text Available Aquaporins (Aqps are integral membrane proteins that facilitate the transport of water and small solutes across cell membranes. Among vertebrate species, Aqps are highly conserved in both gene structure and amino acid sequence. These proteins are vital for maintaining water homeostasis in living organisms, especially for aquatic animals such as teleost fish. Studies on teleost Aqps are mainly limited to several model species with diploid genomes. Common carp, which has a tetraploidized genome, is one of the most common aquaculture species being adapted to a wide range of aquatic environments. The complete common carp genome has recently been released, providing us the possibility for gene evolution of aqp gene family after whole genome duplication.In this study, we identified a total of 37 aqp genes from common carp genome. Phylogenetic analysis revealed that most of aqps are highly conserved. Comparative analysis was performed across five typical vertebrate genomes. We found that almost all of the aqp genes in common carp were duplicated in the evolution of the gene family. We postulated that the expansion of the aqp gene family in common carp was the result of an additional whole genome duplication event and that the aqp gene family in other teleosts has been lost in their evolution history with the reason that the functions of genes are redundant and conservation. Expression patterns were assessed in various tissues, including brain, heart, spleen, liver, intestine, gill, muscle, and skin, which demonstrated the comprehensive expression profiles of aqp genes in the tetraploidized genome. Significant gene expression divergences have been observed, revealing substantial expression divergences or functional divergences in those duplicated aqp genes post the latest WGD event.To some extent, the gene families are also considered as a unique source for evolutionary studies. Moreover, the whole set of common carp aqp gene family provides an

  20. Characterization of a hypoxia-response element in the Epo locus of the pufferfish, Takifugu rubripes.

    Science.gov (United States)

    Kulkarni, Rashmi P; Tohari, Sumanty; Ho, Adrian; Brenner, Sydney; Venkatesh, Byrappa

    2010-06-01

    Animals respond to hypoxia by increasing synthesis of the glycoprotein hormone erythropoietin (Epo) which in turn stimulates the production of red blood cells. The gene encoding Epo has been recently cloned in teleost fishes such as the pufferfish Takifugu rubripes (fugu) and zebrafish (Danio rerio). It has been shown that the transcription levels of Epo in teleost fishes increase in response to anemia or hypoxia in a manner similar to its human ortholog. However, the cis-regulatory element(s) mediating the hypoxia response of Epo gene in fishes has not been identified. In the present study, using the human hepatoma cell line (Hep3B), we have identified and characterized a hypoxia response element (HRE) in the fugu Epo locus. The sequence of the fugu HRE (ACGTGCTG) is identical to that of the HRE in the human EPO locus. However, unlike the HRE in the mammalian Epo locus, which is located in the 3' region of the gene, the fugu HRE is located in the 5' flanking region and on the opposite strand of DNA. This HRE is conserved in other teleosts such as Tetraodon and zebrafish in a similar location. A 365-bp fragment containing the fugu HRE was able to drive GFP expression in the liver of transgenic zebrafish. However, we could not ascertain if the expression of transgene is induced by hypoxia in vivo due to the low and variable levels of GFP expression in transgenic zebrafish. Our investigations also revealed that the Epo locus has experienced extensive rearrangements during vertebrate evolution. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Optimized conditions for primary culture of pituitary cells from the Atlantic cod (Gadus morhua). The importance of osmolality, pCO₂, and pH.

    Science.gov (United States)

    Hodne, Kjetil; von Krogh, Kristine; Weltzien, Finn-Arne; Sand, Olav; Haug, Trude M

    2012-09-01

    Protocols for primary cultures of teleost cells are commonly only moderately adjusted from similar protocols for mammalian cells, the main adjustment often being of temperature. Because aquatic habitats are in general colder than mammalian body temperatures and teleosts have gills in direct contact with water, pH and buffer capacity of blood and extracellular fluid are different in fish and mammals. Plasma osmolality is generally higher in marine teleosts than in mammals. Using Atlantic cod (Gadus morhua) as a model, we have optimized these physiological parameters to maintain primary pituitary cells in culture for an extended period without loosing key properties. L-15 medium with adjusted osmolality, adapted to low pCO(2) (3.8mm Hg) and temperature (12°C), and with pH 7.85, maintained the cells in a physiologically sounder state than traditional culture medium, significantly improving cell viability compared to the initial protocol. In the optimized culture medium, resting membrane potential and response to releasing hormone were stable for at least two weeks, and the proportion of cells firing action potentials during spawning season was about seven times higher than in the original culture medium. The cells were moderately more viable when the modified medium was supplemented with newborn calf serum or artificial serum substitute. Compared to serum-free L-15 medium, expression of key genes (lhb, fshb, and gnrhr2a) was better maintained in medium containing SSR, whereas NCS tended to decrease the expression level. Although serum-free medium is adequate for many applications, serum supplement may be preferable for experiments dependent on membrane integrity. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Comparative study of four interleukin 17 cytokines of tongue sole Cynoglossus semilaevis: Genomic structure, expression pattern, and promoter activity.

    Science.gov (United States)

    Chi, Heng; Sun, Li

    2015-11-01

    The interleukin (IL)-17 cytokine family participates in the regulation of many cellular functions. In the present study, we analyzed the genomic structure, expression, and promoter activity of four IL-17 members from the teleost fish tongue sole (Cynoglossus semilaevis), i.e. CsIL-17C CsIL-17D, CsIL-17F, and IL-17F like (IL-17Fl). We found that CsIL-17C, CsIL-17D, CsIL-17F, and CsIL-17Fl share 21.2%-28.6% overall sequence identities among themselves and 31.5%-71.2% overall sequence identities with their counterparts in other teleost. All four CsIL-17 members possess an IL-17 domain and four conserved cysteine residues. Phylogenetic analysis classified the four CsIL-17 members into three clusters. Under normal physiological conditions, the four CsIL-17 expressed in multiple tissues, especially non-immune tissues. Bacterial infection upregulated the expression of all four CsIL-17, while viral infection upregulated the expression of CsIL-17D and CsIL-17Fl but downregulated the expression of CsIL-17C and CsIL-17F. The 1.2 kb 5'-flanking regions of the four CsIL-17 exhibited apparent promoter activity and contain a number of putative transcription factor-binding sites. Furthermore, the promoter activities of CsIL-17C, CsIL-17D, and CsIL-17F, but not CsIL-17Fl, were modulated to significant extents by lipopolysaccharide, PolyI:C, and PMA. This study provides the first evidence that in teleost, different IL-17 members differ in expression pattern and promoter activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The pyloric caeca area is a major site for IgM(+ and IgT(+ B cell recruitment in response to oral vaccination in rainbow trout.

    Directory of Open Access Journals (Sweden)

    Natalia A Ballesteros

    Full Text Available Although previous studies have characterized some aspects of the immune response of the teleost gut in response to diverse pathogens or stimuli, most studies have focused on the posterior segments exclusively. However, there are still many details of how teleost intestinal immunity is regulated that remain unsolved, including the location of IgM(+ and IgT(+ B cells along the digestive tract and their role during the course of a local stimulus. Thus, in the current work, we have studied the B cell response in five different segments of the rainbow trout (Oncorhynchus mykiss digestive tract in both naïve fish and fish orally vaccinated with an alginate-encapsulated DNA vaccine against infectious pancreatic necrosis virus (IPNV. IgM(+ and IgT(+ cells were identified all along the tract with the exception of the stomach in naïve fish. While IgM(+ cells were mostly located in the lamina propria (LP, IgT(+ cells were primarily localized as intraepithelial lymphocytes (IELs. Scattered IgM(+ IELs were only detected in the pyloric caeca. In response to oral vaccination, the pyloric caeca region was the area of the digestive tract in which a major recruitment of B cells was demonstrated through both real time PCR and immunohistochemistry, observing a significant increase in the number of both IgM(+ and IgT(+ IELs. Our findings demonstrate that both IgM(+ and IgT(+ respond to oral stimulation and challenge the paradigm that teleost IELs are exclusively T cells. Unexpectedly, we have also detected B cells in the fat tissue associated to the digestive tract that respond to vaccination, suggesting that these cells surrounded by adipocytes also play a role in mucosal defense.

  4. Environmental and cortisol-mediated control of Ca(2+) uptake in tilapia (Oreochromis mossambicus).

    Science.gov (United States)

    Lin, Chia-Hao; Kuan, Wei-Chun; Liao, Bo-Kai; Deng, Ang-Ni; Tseng, Deng-Yu; Hwang, Pung-Pung

    2016-04-01

    Ca(2+) is a vital element for many physiological processes in vertebrates, including teleosts, which live in aquatic environments and acquire Ca(2+) from their surroundings. Ionocytes within the adult gills or larval skin are critical sites for transcellular Ca(2+) uptake in teleosts. The ionocytes of zebrafish were found to contain transcellular Ca(2+) transporters, epithelial Ca(2+) channel (ECaC), plasma membrane Ca(2+)-ATPase 2 (PMCA2), and Na(+)/Ca(2+) exchanger 1b (NCX1b), providing information about the molecular mechanism of transcellular Ca(2+) transports mediated by ionocytes in fish. However, more evidence is required to establish whether or not a similar mechanism of transcellular Ca(2+) transport also exists in others teleosts. In the present study, ecac, pmca2, and ncx1 were found to be expressed in the branchial ionocytes of tilapia, thereby providing further support for the mechanism of transcellular Ca(2+) transport through ionocytes previously proposed for zebrafish. In addition, we also reveal that low Ca(2+) water treatment of tilapia stimulates Ca(2+) uptake and expression of ecac and cyp11b (the latter encodes a cortisol-synthesis enzyme). Treatment of tilapia with exogenous cortisol (20 mg/l) enhanced both Ca(2+) influx and ecac expression. Therefore, increased cyp11b expression is suggested to enhance Ca(2+) uptake capacity in tilapia exposed to low Ca(2+) water. Furthermore, the application of cortisol receptor antagonists revealed that cortisol may regulate Ca(2+) uptake through glucocorticoid and/or mineralocorticoid receptor (GR and/or MR) in tilapia. Taken together, the data suggest that cortisol may activate GR and/or MR to execute its hypercalcemic action by stimulating ecac expression in tilapia.

  5. An assessment of the genotoxic impact of the Sea Empress oil spill by the measurement of DNA adduct levels in selected invertebrate and vertebrate species.

    Science.gov (United States)

    Harvey, J S; Lyons, B P; Page, T S; Stewart, C; Parry, J M

    1999-04-26

    The grounding of the Sea Empress oil tanker resulted in the release of 72,000 tonnes of crude oil into Milford Haven, Wales, UK. Our initial studies indicated that this contamination resulted in elevated levels of DNA adducts in one of the area's native marine species Lipophrys pholis [B.P. Lyons, J.S. Harvey, J.M. Parry, An initial assessment of the genotoxic impact of the Sea Empress oil spill by the measurement of DNA adduct levels in the intertidal teleost Lipophrys pholis, Mutat. Res. 390 (1997) 263-268]. These original studies were extended and the genotoxic impact of the oil contamination was investigated in the invertebrates Halichondria panicea and Mytilus edulis, along with the vertebrate fish species L. pholis, Pleuronectes platessa and Limanda limanda. DNA adduct levels were assessed in these species over a period of 2-17 months after the incident. The studies indicate differences in the impact of acute oil contamination upon vertebrate and invertebrate species. The oil contamination did not induce any detectable elevations in adduct levels in the invertebrate species H. panicea and M. edulis. In contrast, the oil contamination did appear to induce adducts in the vertebrate teleost species L. pholis, P. platessa and Lim. limanda. Despite some difficulties in sampling, the data obtained 12-17 months after the spill suggested that the affected species recovered from the oil contamination. While the studies indicate that the genetic impact of the oil contamination was less severe than might have been expected, it remains possible that the DNA adducts detected in the teleosts could lead to genetic changes in these species in the future. Copyright 1999 Elsevier Science B.V.

  6. Exposure to seawater increases intestinal motility in euryhaline rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Brijs, Jeroen; Hennig, Grant W; Gräns, Albin; Dekens, Esmée; Axelsson, Michael; Olsson, Catharina

    2017-07-01

    Upon exposure to seawater, euryhaline teleosts need to imbibe and desalinate seawater to allow for intestinal ion and water absorption, as this is essential for maintaining osmotic homeostasis. Despite the potential benefits of increased mixing and transport of imbibed water for increasing the efficiency of absorptive processes, the effect of water salinity on intestinal motility in teleosts remains unexplored. By qualitatively and quantitatively describing in vivo intestinal motility of euryhaline rainbow trout ( Oncorhynchus mykiss ), this study demonstrates that, in freshwater, the most common motility pattern consisted of clusters of rhythmic, posteriorly propagating contractions that lasted ∼1-2 min followed by a period of quiescence lasting ∼4-5 min. This pattern closely resembles mammalian migrating motor complexes (MMCs). Following a transition to seawater, imbibed seawater resulted in a significant distension of the intestine and the frequency of MMCs increased twofold to threefold with a concomitant reduction in the periods of quiescence. The increased frequency of MMCs was also accompanied by ripple-type contractions occurring every 12-60 s. These findings demonstrate that intestinal contractile activity of euryhaline teleosts is dramatically increased upon exposure to seawater, which is likely part of the overall response for maintaining osmotic homeostasis as increased drinking and mechanical perturbation of fluids is necessary to optimise intestinal ion and water absorption. Finally, the temporal response of intestinal motility in rainbow trout transitioning from freshwater to seawater coincides with previously documented physiological modifications associated with osmoregulation and may provide further insight into the underlying reasons shaping the migration patterns of salmonids. © 2017. Published by The Company of Biologists Ltd.

  7. Sex change strategy and the aromatase genes.

    Science.gov (United States)

    Gardner, L; Anderson, T; Place, A R; Dixon, B; Elizur, A

    2005-04-01

    Sequential hermaphroditism is a common reproductive strategy in many teleosts. Steroid production is known to mediate both the natural and induced sex change, yet beyond this the physiology directing this process has received little attention. Cytochrome P450 aromatase is a key enzyme in the hormonal pathway catalysing the conversion of sex steroids, androgens to oestrogens, and thus is highly relevant to the process of sex change. This study reports the isolation of cDNA sequences for aromatase isoforms CYP19A1 and CYP19A2 from teleost species representing three forms of sexual hermaphroditism: Lates calcarifer (protandry), Cromileptes altivelis (protogyny), and Gobiodon histrio (bi-directional). Deduced amino acid analysis of these isoforms with other reported isoforms from gonochoristic (single sex) teleosts revealed 56-95% identity within the same isoform while only 48-65% identity between isoforms irrespective of species and sexual strategy. Phylogenetic analysis supported this result separating sequences into isoform exclusive clades in spite of species apparent evolutionary distance. Furthermore, this study isolates 5' flanking regions of all above genes and describes putative cis-acting elements therein. Elements identified include steroidogenic factor 1 binding site (SF-1), oestrogen response element (ERE), progesterone response element (PRE), androgen response element (ARE), glucocorticoid response elements (GRE), peroxisome proliferator-activated receptor alpha/retinoid X receptor alpha heterodimer responsive element (PPARalpha/RXRalpha), nuclear factor kappabeta (NF-kappabeta), SOX 5, SOX 9, and Wilms tumor suppressor (WTI). A hypothetical in vivo model was constructed for both isoforms highlighting potential roles of these putative cis-acting elements with reference to normal function and sexual hermaphroditism.

  8. An exceptionally preserved Eocene shark and the rise of modern predator-prey interactions in the coral reef food web.

    Science.gov (United States)

    Fanti, Federico; Minelli, Daniela; Conte, Gabriele Larocca; Miyashita, Tetsuto

    2016-01-01

    Following extreme climatic warming events, Eocene Lagerstätten document aquatic and terrestrial vertebrate faunas surprisingly similar to modern counterparts. This transition in marine systems is best documented in the earliest teleost-dominated coral reef assemblage of Pesciara di Bolca, northern Italy, from near the end of the Eocene Climatic Optimum. Its rich fauna shows similarities with that of the modern Great Barrier Reef in niche exploitation by and morphological disparity among teleost primary consumers. However, such paleoecological understanding has not transcended trophic levels above primary consumers, particularly in carcharhiniform sharks. We report an exceptionally preserved fossil school shark (Galeorhinus cuvieri) from Pesciara di Bolca. In addition to the spectacular preservation of soft tissues, including brain, muscles, and claspers, this male juvenile shark has stomach contents clearly identifiable as a sphyraenid acanthomorph (barracuda). This association provides evidence that a predator-prey relationship between Galeorhinus and Sphyraena in the modern coral reefs has roots in the Eocene. A growth curve of the living species of Galeorhinus fitted to G. cuvieri suggests that all specimens of G. cuvieri from the lagoonal deposits of Bolca represent sexually and somatically immature juveniles. The modern trophic association between higher-degree consumers (Galeorhinus and Sphyraena) has a counterpart in the Eocene Bolca, just as Bolca and the Great Barrier Reef show parallels among teleost primary consumers. Given the age of Bolca, trophic networks among consumers observed in modern coral reefs arose by the exit from the Climatic Optimum. The biased representation of juveniles suggests that the Bolca Lagerstätte served as a nursery habitat for G. cuvieri. Ultraviolet photography may be useful in probing for exceptional soft tissue preservation before common acid preparation methods.

  9. Identification and characterisation of TLR18-21 genes in Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Lee, P T; Zou, J; Holland, J W; Martin, S A M; Collet, B; Kanellos, T; Secombes, C J

    2014-12-01

    Teleost fish possess many types of toll-like receptor (TLR) some of which exist in other vertebrate groups and some that do not (ie so-called "fish-specific" TLRs). In this study, we identified in Atlantic salmon (Salmo salar) whole-genome shotgun (WGS) contigs seven TLRs that are not found in mammals, including six types of fish-specific TLRs (one TLR18, one TLR19, and four TLR20 members (two of which are putative soluble forms (s)) and one TLR21. Phylogenetic analysis revealed that teleost TLR19-21 are closely related with murine TLR11-TLR13, whilst teleost TLR18 groups with mammalian TLR1, 2, 6 and 10. A typical TLR protein domain structure was found in all these TLRs with the exception of TLR20b(s) and TLR20c(s). TLR-GFP expression plasmids transfected into SHK-1 cells showed that salmon TLR19, TLR20a and TLR20d were preferentially localised to the intracellular compartment. Real time PCR analysis suggested that salmon TLR19-TLR21 are mainly expressed in immune related organs, such as spleen, head kidney and gills, while TLR18 transcripts are more abundant in muscle. In vitro stimulation of primary head kidney cells with type I IFN, IFNγ and IL-1β had no impact on TLR expression. Infectious salmon anaemia virus (ISAV) infection, in vivo, down-regulated TLR20a, TLR20b(s), TLR20d and TLR21 in infected salmon kidney tissue. In contrast, up-regulation of TLR19 and TLR20a expression was found in posterior kidney in rainbow trout with clinical proliferative kidney disease (PKD). Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Factors influencing in vitro respiratory burst assays with head kidney leucocytes from rainbow trout, Oncorhynchus mykiss (Walbaum)

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Holten-Andersen, Lars; Buchmann, Kurt

    Head kidney leukocytes are central elements in a number of in vivo and in vitro assays elucidating innate and adaptive immune mechanisms in teleosts following stimulation with various antigens. These systems are sensitive to a number of factors affecting the outcome of the assays. The present work...... from cells in a concentration of 1 x 104 cells/ml. Co-incubation of cells with inhibitory substances (DiMePE2, cortisol and SOD) decreased the RBA. It is concluded that several biotic and abiotic factors should be taken into account when conducting RBA assays with head kidney leukocytes for elucidation...

  11. Arsenic concentrations correlate with salinity for fish taken from the North Sea and Baltic waters

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Francesconi, K. A.

    2003-01-01

    Total arsenic concentrations were determined in three teleost species (herring Clupea harengus; cod Gadus morhua, and flounder Platichthys flesus) taken. from four locations in the Baltic and North Sea with salinities ranging from 8 to 32 psu. Individual arsenic concentrations ranged from 0.......04 to 10.9 mg/kg wet mass, and there was a positive linear relationship between arsenic concentration and salinity for all three species (r(2) 0.44 to 0.72, all P arsenic than do freshwater fish, the data reported...... here are the first showing a relationship between the total arsenic concentration in fish and salinity....

  12. Interactions between Manta birostris and Sotalia guianensis in a World Heritage listed Brazilian estuary.

    Science.gov (United States)

    Domit, C; Broadhurst, M K; Bornatowski, H

    2017-10-01

    During 1442 h of visual observations over 7 years throughout the World Heritage listed Paranaguá estuarine complex, Brazil, seven occurrences of interactions were observed at a single location involving breaching Manta birostris displacing schools of teleosts, which were subsequently preyed upon by Sotalia guianensis. Although the interactions were not definitively categorized as being amensal, commensal or mutual, their restriction to isolated space (adjacent to a protected area) and time (summer) supports previous assertions the area is important to regional productivity and the continuation of protected-area status. © 2017 The Fisheries Society of the British Isles.

  13. The zebrafish genome: a review and msx gene case study.

    Science.gov (United States)

    Postlethwait, J H

    2006-01-01

    Zebrafish is one of several important teleost models for understanding principles of vertebrate developmental, molecular, organismal, genetic, evolutionary, and genomic biology. Efficient investigation of the molecular genetic basis of induced mutations depends on knowledge of the zebrafish genome. Principles of zebrafish genomic analysis, including gene mapping, ortholog identification, conservation of syntenies, genome duplication, and evolution of duplicate gene function are discussed here using as a case study the zebrafish msxa, msxb, msxc, msxd, and msxe genes, which together constitute zebrafish orthologs of tetrapod Msx1, Msx2, and Msx3. Genomic analysis suggests orthologs for this difficult to understand group of paralogs.

  14. OTOLITH MASS ASYMMETRY IN CARANGOIDES CAERULEPINNATUS (RÜPPELL, 1830 (FAMILY: CARANGIDAE COLLECTED FROM THE SEA OF OMAN

    Directory of Open Access Journals (Sweden)

    Laith Jawad

    2013-04-01

    Full Text Available The sagittae mass asymmetry was studied in the teleost Carangoides caeruleopinnatus. The value of the asymmetry was calculated as the difference between the mass of the right and left paired otoliths, divided by average otolith mass. The results show that the absolute value of X in C. caeruleopinnatus does not depend on fish length and otolith growth rate, as it does in other symmetrical fish species. However, the absolute value of otolith mass difference increases with the fish length. The value of x falls between -0.2 and +0.2.

  15. Physiological and behavioral reactions of fishes to temperature change

    Energy Technology Data Exchange (ETDEWEB)

    Crawshaw, L I

    1977-05-01

    Teleost fishes possess a central nervous system thermoregulatory mechanism remarkably similar to that of other vertebrates. Inputs from peripheral and anterior brainstem thermosensitive elements are integrated to effect appropriate thermoregulatory responses. The integrated output signal from the thermoregulatory center also appears to provide an input to the respiratory system. Short-term deviations from a given temperature alter respiratory requirements, produce acid-base imbalance, and cause disturbances in fluid-electrolyte regulation. Acclimation to a given temperature involves changes that counteract these disturbances.

  16. On the Role of Neurogenesis and Neural Plasticity in the Evolution of Animal Personalities and Stress Coping Styles

    DEFF Research Database (Denmark)

    Overli, Oyvind; Sorensen, Christina

    2016-01-01

    and neurogenesis have received recent attention. This work reveals that brain cell proliferation and neurogenesis are associated with heritable variation in stress coping style, and they are also differentially affected by short- and long-term stress in a biphasic manner. Routine-dependent and inflexible behavior...... are conserved throughout the vertebrate subphylum, including factors affecting perception, learning, and memory of stimuli and events. Here we review conserved aspects of the contribution of neurogenesis and other aspects of neural plasticity to stress coping. In teleost fish, brain cell proliferation...

  17. Inorganic, organic, and encapsulated minerals in vegetable meal based diets for Sparus aurata (Linnaeus, 1758)

    OpenAIRE

    Domínguez, David; Rimoldi, Simona; Robaina, Lidia E.; Torrecillas, Silvia; Terova, Genciana; Zamorano, María J.; Karalazos, Vasileios; Hamre, Kristin; Izquierdo, Marisol

    2017-01-01

    Substituting fishmeal (FM) with vegetable meal (VM) can markedly affect the mineral composition of feeds, and may require additional mineral supplementation. Their bioavailability and optimal supplementation levels depend also on the form of delivery of minerals. The aim of the study was to determine the effect of different delivery forms of three major trace elements (Zn, Mn and Se) in a marine teleost. Gilthead sea bream juveniles of 22.5 g were fed a VM-based diet for 12 weeks that was eit...

  18. Reflex bradycardia does not influence oxygen consumption during hypoxia in the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Iversen, Nina Kerting; McKenzie, David; Malte, H.

    2010-01-01

    the bradycardia on oxygen consumption (MO2), standard metabolic rate (SMR) and the critical oxygen partial pressure for regulation of SMR in hypoxia (Pcrit) in European eels Anguilla anguilla (mean ± SEM mass 528 ± 36 g; n = 14). Eels were instrumented with a Transonic flow probe around the ventral aorta......Most teleost fish reduce heart rate when exposed to acute hypoxia. This hypoxic bradycardia has been characterised for many fish species, but it remains uncertain whether this reflex contributes to the maintenance of oxygen uptake in hypoxia. Here we describe the effects of inhibiting...

  19. Vertebrate beta-thymosins: conserved synteny reveals the relationship between those of bony fish and of land vertebrates.

    Science.gov (United States)

    Edwards, John

    2010-03-05

    Using conservation of synteny I show how the four thymosins expressed by teleost fish are related to the three of tetrapods, which is not evident from their protein sequences. This clarification was aided by identification of a novel thymosin of reptilians that replaces the beta10 thymosin of mammals. Recent reconstruction of the ancestral vertebrate genome suggests that divergence of beta-thymosins began with duplication preceding the two rounds of whole genome duplication. Copyright (c) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  20. Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean

    International Nuclear Information System (INIS)

    Dirtu, Alin C.; Malarvannan, Govindan; Das, Krishna; Dulau-Drouot, Violaine; Kiszka, Jeremy J.; Lepoint, Gilles; Mongin, Philippe; Covaci, Adrian

    2016-01-01

    Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ 13 C and δ 15 N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ 15 N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation. - Highlights: • POPs and total Hg were

  1. Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Dirtu, Alin C. [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Chemistry, “Al. I. Cuza” University of Iasi, 700506 Iasi (Romania); Malarvannan, Govindan [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Das, Krishna [University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege (Belgium); Dulau-Drouot, Violaine [Groupe Local d’Observation et d’Identification des Cétacés (GLOBICE), 30 Chemin Parc Cabris, Grand Bois, 97410 Saint Pierre, La Réunion (France); Kiszka, Jeremy J. [Marine Sciences Program, Department of Biological Sciences, Florida International University, 3000 NE 151st, North Miami, FL 33181 (United States); Lepoint, Gilles [University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege (Belgium); Mongin, Philippe [Brigade Nature Océan Indien (BNOI)/ONCFS, 12 Allée de la Foret – Parc de la Providence, 97400 Saint Denis, La Réunion (France); Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2016-04-15

    Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ{sup 13}C and δ{sup 15}N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ{sup 15}N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation. - Highlights: • POPs and total

  2. Ovarian follicle maturation and ovulation: An integrated perspective

    Science.gov (United States)

    Patino, R.; Thomas, P.; Yoshizaki, G.

    2003-01-01

    Numerous studies with teleosts have addressed the regulation and mechanisms of oocyte maturation, but largely at the exclusion of ovulation. A smaller but still considerable number of studies have focused on ovulation, and ignored maturation. Consequently, little is known about the mechanistic linkages between these two events. New information is presented here indicating that luteinizing hormone regulates the acquisition not only of oocyte maturational competence, but also ovulatory competence. The thesis is presented that maturation and ovulation are closely integrated and overlapping events that are best viewed conceptually and experimentally as parts of a functional whole. ?? 2004 Kluwer Academic Publishers.

  3. The extracellular matrix of Gadus morhua muscle contains types III, V, VI and IV collagens in addition to type I

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Lawson, M.A.

    2005-01-01

    Confocal microscopy and immuno‐histochemistry were used to examine collagens in the extracellular matrix of cod Gadus morhua swimming muscle. In addition to the well known presence of type I fibrous collagen, types III and VI were also found in the myocommata and the endomysium. The beaded collagen......, type VI, was found in the endomysium and the network forming collagen, type IV, was found in the basement membrane. This is the first report of type V collagen in cod muscle and of types II, IV and VI in the muscle of a teleost....

  4. Female crucian carp, Carassius carassius, lose predator avoidance behavior when getting ready to mate

    DEFF Research Database (Denmark)

    Lastein, S.; Höglund, Erik; Mayer, I.

    2008-01-01

    -dependent; for instance, many animals show increased risk-taking during courtship behavior by paying less attention to potential predators. We investigated whether the fright reaction, a stereotypical avoidance response to olfactory cues from injured conspecifics, may be affected by reproductive status in a teleost fish...... maturation, were lower in the individuals not responding with a fright reaction compared to those responding. In males, there were no differences between responsive and non-responsive individuals in mean plasma levels of androgens (testosterone and 11-ketotestosterone) involved in spermatogenesis and male...

  5. Redescriptions of two frequently recorded but poorly known hemiurid digeneans, Lecithochirium musculus (Looss, 1907) (Lecithochiriinae) and Ectenurus lepidus Looss, 1907 (Dinurinae), based on material from the western Mediterranean

    Czech Academy of Sciences Publication Activity Database

    Carreras-Aubets, M.; Montero, E. E.; Kostadinova, Aneta; Gibson, D. I.; Carrasson, M.

    2012-01-01

    Roč. 82, č. 3 (2012), s. 185-199 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : EELS ANGUILLA-ANGUILLA * HELMINTH-PARASITES * MARINE FISHES * CONGER-CONGER * COASTAL LAGOONS * TELEOST FISH * EUROPEAN EEL * COMMUNITIES * TREMATODES * DIVERSITY Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.260, year: 2012 http://link.springer.com/article/10.1007%2Fs11230-012-9357-8

  6. Nodal signals mediate interactions between the extra-embryonic and embryonic tissues in zebrafish

    OpenAIRE

    Xiang, Fan; Hagos, Engda G.; Xu, Bo; Sias, Christina; Kawakami, Koichi; Burdine, Rebecca D.; Dougan, Scott T.

    2007-01-01

    In many vertebrates, extra-embryonic tissues are important signaling centers that induce and pattern the germ layers. In teleosts, the mechanism by which the extra-embryonic yolk syncytial layer (YSL) patterns the embryo is not understood. Although the Nodal-related protein Squint is expressed in the YSL, its role in this tissue is not known. We generated a series of stable transgenic lines with GFP under the control of squint genomic sequences. In all species, nodal-related genes induce thei...

  7. Evolution of the interaction between Runx2 and VDR, two transcription factors involved in osteoblastogenesis

    Directory of Open Access Journals (Sweden)

    Barriga Elias H

    2010-03-01

    Full Text Available Abstract Background The mineralized skeleton is a major evolutionary novelty that has contributed to the impressive morphological diversifications of the vertebrates. Essential to bone biology is the solidified extracellular matrix secreted by highly specialized cells, the osteoblasts. We now have a rather complete view of the events underlying osteogenesis, from a cellular, molecular, genetic, and epigenetic perspective. Because this knowledge is still largely restricted to mammals, it is difficult, if not impossible, to deduce the evolutionary history of the regulatory network involved in osteoblasts specification and differentiation. In this study, we focused on the transcriptional regulators Runx2 and VDR (the Vitamin D Receptor that, in mammals, directly interact together and stabilize complexes of co-activators and chromatin remodellers, thereby allowing the transcriptional activation of target genes involved in extracellular matrix mineralization. Using a combination of functional, biochemical, and histological approaches, we have asked if the interaction observed between Runx2 and VDR represents a recent mammalian innovation, or if it results from more ancient changes that have occurred deep in the vertebrate lineage. Results Using immunohistochemistry and in situ hybridization in developing embryos of chick, frog and teleost fishes, we have revealed that the co-expression of Runx2 and VDR in skeletal elements has been particularly strengthened in the lineage leading to amniotes. We show that the teleost Runx2 orthologue as well as the three mammalian Runx1, Runx2 and Runx3 paralogues are able to co-immunoprecipitate with the VDR protein present in nuclear extracts of rat osteoblasts stimulated with 1α,25-dihydroxyvitamin D3. In addition, the teleost Runx2 can activate the transcription of the mammalian osteocalcin promoter in transfection experiments, and this response can be further enhanced by 1α,25-dihydroxyvitamin D3. Finally

  8. Root Effect Haemoglobins in Fish May Greatly Enhance General Oxygen Delivery Relative to Other Vertebrates.

    Directory of Open Access Journals (Sweden)

    Jodie L Rummer

    Full Text Available The teleost fishes represent over half of all extant vertebrates; they occupy nearly every body of water and in doing so, occupy a diverse array of environmental conditions. We propose that their success is related to a unique oxygen (O2 transport system involving their extremely pH-sensitive haemoglobin (Hb. A reduction in pH reduces both Hb-O2 affinity (Bohr effect and carrying capacity (Root effect. This, combined with a large arterial-venous pH change (ΔpHa-v relative to other vertebrates, may greatly enhance tissue oxygen delivery in teleosts (e.g., rainbow trout during stress, beyond that in mammals (e.g., human. We generated oxygen equilibrium curves (OECs at five different CO2 tensions for rainbow trout and determined that, when Hb-O2 saturation is 50% or greater, the change in oxygen partial pressure (ΔPO2 associated with ΔpHa-v can exceed that of the mammalian Bohr effect by at least 3-fold, but as much as 21-fold. Using known ΔpHa-v and assuming a constant arterial-venous PO2 difference (Pa-vO2, Root effect Hbs can enhance O2 release to the tissues by 73.5% in trout; whereas, the Bohr effect alone is responsible for enhancing O2 release by only 1.3% in humans. Disequilibrium states are likely operational in teleosts in vivo, and therefore the ΔpHa-v, and thus enhancement of O2 delivery, could be even larger. Modeling with known Pa-vO2 in fish during exercise and hypoxia indicates that O2 release from the Hb and therefore potentially tissue O2 delivery may double during exercise and triple during some levels of hypoxia. These characteristics may be central to performance of athletic fish species such as salmonids, but may indicate that general tissue oxygen delivery may have been the incipient function of Root effect Hbs in fish, a trait strongly associated with the adaptive radiation of teleosts.

  9. Abundance of specific mRNA transcripts impacts hatching success in European eel, Anguilla anguilla L

    DEFF Research Database (Denmark)

    Rozenfeld, Christoffer; Butts, Ian A.E.; Tomkiewicz, Jonna

    2016-01-01

    -tubulin, insulin-like growth factor 2 (igf2), nucleoplasmin (npm2), prohibitin 2 (phb2), phosphatidylinositol glycan biosynthesis class F protein 5 (pigf5), and carnitine O-palmitoyltransferase liver isoform-like 1 (cpt1) are associated with embryonic developmental competence in other teleosts. Here, the relations...... and no hatching groups for any of the selected genes at 0, 2.5, and 5 HPF. However, at 30 HPF the hatch group showed significantly higher abundance of cpt1a, cpt1b, β-tubulin, phb2, and pigf5 transcripts than the no hatch group. Therefore, these results indicate that up-regulation of the transcription...

  10. Tilapia and human CLIC2 structures are highly conserved.

    Science.gov (United States)

    Zeng, Jiao; Li, Zhengjun; Lui, Eei Yin; Lam, Siew Hong; Swaminathan, Kunchithapadam

    2018-01-08

    Chloride intracellular channels (CLICs) exist in soluble and membrane bound forms. We have determined the crystal structure of soluble Clic2 from the euryhaline teleost fish Oreochromis mossambicus. Structural comparison of tilapia and human CLIC2 with other CLICs shows that these proteins are highly conserved. We have also compared the expression levels of clic2 in selected osmoregulatory organs of tilapia, acclimated to freshwater, seawater and hypersaline water. Structural conservation of vertebrate CLICs implies that they might play conserved roles. Also, tissue-specific responsiveness of clic2 suggests that it might be involved in iono-osmoregulation under extreme conditions in tilapia. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. IGF-I and branchial IGF receptor expression and localization during salinity acclimation in striped bass

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbaek; Luckenbach, John Adam; Madsen, Steffen

    2007-01-01

    The initial response of the IGF-I system and the expression and cellular localization of IGF type-I receptor (IGF-IR) were studied in the gill of a euryhaline teleost during salinity acclimation. Exposure of striped bass (Morone saxatilis) to hyperosmotic and hypoosmotic challenges induced small...... in either plasma IGF-I, liver, or gill IGF-I mRNA, or gill IGF-IR mRNA levels. In a separate experiment, FW-acclimated fish were injected with saline or IGF-I prior to a 24-h SW challenge. Rapid regain of osmotic balance following SW transfer was hindered by IGF-I. Immunohistochemistry revealed...

  12. Biological observations on the broadfin shark Lamiopsis temminckii (Carcharhiniformes: Carcharhinidae).

    Science.gov (United States)

    Akhilesh, K V; Purushottama, G B; Thakurdas; Kizhakudan, S J

    2017-12-01

    Biological information was collected from 214 individuals of the broadfin shark Lamiopsis temminckii measuring 418 to 1782 mm total length, L T . Size at maturity (L 50 ) for females and males was estimated at 1430 and 1368 mm L T , respectively, while mature and gravid females were observed from 1350 mm L T with litter sizes 2-8 and size at birth 418-650 mm L T . Analysis of stomach contents revealed a variety of prey, primarily crustaceans (54·0%), teleosts (42·7%) and cephalopods. © 2017 The Fisheries Society of the British Isles.

  13. Emergence, development and diversification of the TGF-beta signalling pathway within the animal kingdom.

    Science.gov (United States)

    Huminiecki, Lukasz; Goldovsky, Leon; Freilich, Shiri; Moustakas, Aristidis; Ouzounis, Christos; Heldin, Carl-Henrik

    2009-02-03

    The question of how genomic processes, such as gene duplication, give rise to co-ordinated organismal properties, such as emergence of new body plans, organs and lifestyles, is of importance in developmental and evolutionary biology. Herein, we focus on the diversification of the transforming growth factor-beta (TGF-beta) pathway -- one of the fundamental and versatile metazoan signal transduction engines. After an investigation of 33 genomes, we show that the emergence of the TGF-beta pathway coincided with appearance of the first known animal species. The primordial pathway repertoire consisted of four Smads and four receptors, similar to those observed in the extant genome of the early diverging tablet animal (Trichoplax adhaerens). We subsequently retrace duplications in ancestral genomes on the lineage leading to humans, as well as lineage-specific duplications, such as those which gave rise to novel Smads and receptors in teleost fishes. We conclude that the diversification of the TGF-beta pathway can be parsimoniously explained according to the 2R model, with additional rounds of duplications in teleost fishes. Finally, we investigate duplications followed by accelerated evolution which gave rise to an atypical TGF-beta pathway in free-living bacterial feeding nematodes of the genus Rhabditis. Our results challenge the view of well-conserved developmental pathways. The TGF-beta signal transduction engine has expanded through gene duplication, continually adopting new functions, as animals grew in anatomical complexity, colonized new environments, and developed an active immune system.

  14. Reproductive biology and diet of Mustelus punctulatus (Risso, 1826 (Chondrichthyes: Triakidae from the Gulf of Gabès, central Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Bechir Saïdi

    2009-06-01

    Full Text Available Specimens of Mustelus punctulatus were collected between January 2002 and December 2005 from commercial fisheries in the Gulf of Gabès (central Mediterranean Sea. Males and females reached a maximum total length (TL of 111 and 122 cm respectively. Males matured between 76 and 88.5 cm TL, with a size at maturity (TL50 of 81.4 cm TL. Females matured between 88 and 100 cm TL with a TL50 of 95.6 cm. Females had an annual reproductive cycle. Mating occurred through late-May and June. Ovulation occurred from early July to mid-August with parturition occurring from mid-May to early June, after a gestation period of 11 months. The size at birth was estimated to be 24.5 to 30.5 cm TL. Positive linear relationships were detected between the TL of mature females and ovarian and uterine fecundities. Mustelus punctulatus is an opportunistic predator that consumes a wide range of demersal and benthic prey items. It preys mainly on crustaceans, teleosts and molluscs. Polychaetes, sipunculids, echinoderms and tunicates are also consumed. The species change their main food item as they grow, from crustaceans to teleosts then to molluscs.

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

    Science.gov (United States)

    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.

  16. Two visual pathways to the telencephalon in the nurse shark (Ginglymostoma cirratum). I. Retinal projections.

    Science.gov (United States)

    Luiten, P G

    1981-03-10

    The central projections of the retina in the nurse shark were studied by anterograde transport of horseradish peroxidase and tritiated proline. With regard to efferent retinal fibers, both techniques gave completely identical results. Projections were found to pretectal area, dorsal thalamus, basal optic nucleus, and optic tectum, all at the contralateral side. The retinal target cells in the dorsal thalamus are restricted to the ventrolateral optic nucleus and the posterior optic nucleus. No evidence was found for an earlier-reported projection to the lateral geniculate nucleus. The present findings show that the ventrolateral optic nucleus exhibits homological features of the dorsal lateral geniculate nucleus in other vertebrate groups, whereas the lateral geniculate nucleus of the nurse shark is much more comparable to the nucleus rotundus of teleosts and birds and would be more appropriately so named. The application of the HRP technique also allowed us to study afferents to the retina by retrograde transport of tracer. Retrogradely labeled cells were observed in the contralateral optic tectum and are apparently similar to those reported for teleosts and birds.

  17. Ocular anatomy of the black pacu (Colossoma macropomum): gross, histologic, and diagnostic imaging.

    Science.gov (United States)

    Gustavsen, Kate A; Paul-Murphy, Joanne R; Weber, Ernest Scott; Zwingenberger, Allison L; Dunker, Freeland H; Dubielzig, Richard R; Reilly, Christopher M; Murphy, Christopher J

    2018-01-30

    To describe the ocular anatomy of the black pacu (Colossoma macropomum), a freshwater teleost fish of the Amazon River basin, including an unusual choroid laden with adipose tissue. Three adult black pacu were anesthetized and examined clinically and with ocular ultrasonography, then euthanized. Three fish were euthanized and their heads imaged immediately postmortem using computed tomography. One fish was euthanized and its exenterated eyes imaged by high-resolution magnetic resonance imaging. The exenterated eyes of all seven fish were fixed in formalin; eyes from three fish were examined grossly and histologically. Additionally, archived histologic sections from two smaller black pacu specimens were examined. Findings were consistent among the ocular imaging modalities used. Intrinsic to the sclera were circumferential ossicles and scleral cartilage. The lens was spherical and protruded through the ovoid pupil with an aphakic space inferiorly when the accommodative mechanism was relaxed under anesthesia. Both a small falciform process and epiretinal vasculature were present in the posterior segment. The retina was cone-rich, and processes of the retinal pigment epithelium enveloped the photoreceptor outer segments. Remarkably, the choroid occupied one-third of the anteroposterior length of the globe; histology confirmed that the bulk of the choroid was composed of adipose tissue. The eye of the pacu overall is typical of teleosts but has the notable and consistent finding of a substantive store of choroidal fat of unknown function. © 2018 American College of Veterinary Ophthalmologists.

  18. Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae in an estuarine environment in southern Brazil

    Directory of Open Access Journals (Sweden)

    Marta J. Cremer

    2012-06-01

    Full Text Available The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%, while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05 and biomass (z = -2.46; n = 40; p<0.05. All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.

  19. Immunohistochemical localization of cocaine- and amphetamine-regulated transcript peptide (CARTp) in the brain of the pigeon (Columba livia) and zebra finch (Taeniopygia guttata).

    Science.gov (United States)

    Gutierrez-Ibanez, Cristian; Iwaniuk, Andrew N; Jensen, Megan; Graham, David J; Pogány, Ákos; Mongomery, Benjamin C; Stafford, James L; Luksch, Harald; Wylie, Douglas R

    2016-12-15

    Cocaine- and amphetamine-regulated transcript peptides (CARTp) are neuropeptides that act as neurotransmitters in the brain of vertebrates. The expression of CARTp has been characterized in teleosts, amphibians, and several mammalian species, but comparative data in reptiles and birds are nonexistent. In this study, we show the distribution of immunoreactivity against CART peptides (CARTp-ir) in the brains of two bird species: the pigeon (Columba livia) and zebra finch (Taeniopygia guttata). We found CARTp-ir cells and terminals in the brains of both, but no major differences between the two species. As in mammals, teleost fish, and amphibians, CARTp-ir terminals and cells were abundant in subpallial regions, particularly the striatum and nucleus accumbens. We also found CARTp-ir cells and terminals in the hypothalamus, and a large number of CARTp-ir terminals in the substantia nigra, ventral tegmental area, periaqueductal gray, parabrachial nucleus, and dorsal vagal complex. However, in contrast to other vertebrates, CARTp-ir was not found in the olfactory bulb. In addition there was almost no CARTp-ir in the pallium or the hippocampal formation, and little CARTp-ir in the cerebellum. The conserved expression of CARTp in the subpallium, hypothalamus, and dorsal vagal complex of birds suggests that some of the functions of CARTp, such as regulation of food intake and interactions with the social control network and mesolimbic reward system, are conserved among vertebrates. J. Comp. Neurol. 524:3747-3773, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. New insights into gill ionocyte and ion transporter function in euryhaline and diadromous fish

    Science.gov (United States)

    Hiroi, Junya; McCormick, Stephen D.

    2012-01-01

    Teleost fishes are able to acclimatize to seawater by secreting excess NaCl by means of specialized “ionocytes” in the gill epithelium. Antibodies against Na+/K+-ATPase (NKA) have been used since 1996 as a marker for identifying branchial ionocytes. Immunohistochemistry of NKA by itself and in combination with Na+/K+/2Cl− cotransporter and CFTR Cl− channel provided convincing evidence that ionocytes are functional during seawater acclimation, and also revealed morphological variations in ionocytes among teleost species. Recent development of antibodies to freshwater- and seawater-specific isoforms of the NKA alpha-subunit has allowed functional distinction of ion absorptive and secretory ionocytes in Atlantic salmon. Cutaneous ionocytes of tilapia embryos serve as a model for branchial ionocytes, allowing identification of 4 types: two involved in ion uptake, one responsible for salt secretion and one with unknown function. Combining molecular genetics, advanced imaging techniques and immunohistochemistry will rapidly advance our understanding of both the unity and diversity of ionocyte function and regulation in fish osmoregulation.