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Sample records for directs zebrafish period2

  1. Direct Visualization of DNA Replication Dynamics in Zebrafish Cells.

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    Kuriya, Kenji; Higashiyama, Eriko; Avşar-Ban, Eriko; Tamaru, Yutaka; Ogata, Shin; Takebayashi, Shin-ichiro; Ogata, Masato; Okumura, Katsuzumi

    2015-12-01

    Spatiotemporal regulation of DNA replication in the S-phase nucleus has been extensively studied in mammalian cells because it is tightly coupled with the regulation of other nuclear processes such as transcription. However, little is known about the replication dynamics in nonmammalian cells. Here, we analyzed the DNA replication processes of zebrafish (Danio rerio) cells through the direct visualization of replicating DNA in the nucleus and on DNA fiber molecules isolated from the nucleus. We found that zebrafish chromosomal DNA at the nuclear interior was replicated first, followed by replication of DNA at the nuclear periphery, which is reminiscent of the spatiotemporal regulation of mammalian DNA replication. However, the relative duration of interior DNA replication in zebrafish cells was longer compared to mammalian cells, possibly reflecting zebrafish-specific genomic organization. The rate of replication fork progression and ori-to-ori distance measured by the DNA combing technique were ∼ 1.4 kb/min and 100 kb, respectively, which are comparable to those in mammalian cells. To our knowledge, this is a first report that measures replication dynamics in zebrafish cells.

  2. Directed Differentiation of Zebrafish Pluripotent Embryonic Cells to Functional Cardiomyocytes

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    Yao Xiao

    2016-09-01

    Full Text Available A cardiomyocyte differentiation in vitro system from zebrafish embryos remains to be established. Here, we have determined pluripotency window of zebrafish embryos by analyzing their gene-expression patterns of pluripotency factors together with markers of three germ layers, and have found that zebrafish undergoes a very narrow period of pluripotency maintenance from zygotic genome activation to a brief moment after oblong stage. Based on the pluripotency and a combination of appropriate conditions, we established a rapid and efficient method for cardiomyocyte generation in vitro from primary embryonic cells. The induced cardiomyocytes differentiated into functional and specific cardiomyocyte subtypes. Notably, these in vitro generated cardiomyocytes exhibited typical contractile kinetics and electrophysiological features. The system provides a new paradigm of cardiomyocyte differentiation from primary embryonic cells in zebrafish. The technology provides a new platform for the study of heart development and regeneration, in addition to drug discovery, disease modeling, and assessment of cardiotoxic agents.

  3. Direction selectivity in the larval zebrafish tectum is mediated by asymmetric inhibition

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    Abhinav eGrama

    2012-09-01

    Full Text Available The extraction of the direction of motion is an important computation performed by many sensory systems and in particular, the mechanism by which direction selective ganglion cells (DS-RGCs in the retina acquire their selective properties, has been studied extensively. However, whether DS-RGCs simply relay this information to downstream areas or whether additional and potentially de-novo processing occurs in these recipient structures is a matter of great interest. Neurons in the larval zebrafish tectum, the largest retino-recipent area in this animal, show direction selective responses to moving visual stimuli but how these properties are acquired is still unknown. In order to study this, we first used two-photon calcium imaging to classify the population responses of tectal cells to bars moving at different speeds and in different directions. Subsequently, we performed in-vivo whole cell electrophysiology on these direction selective tectal neurons and we found that their inhibitory inputs were strongly biased towards the null direction of motion, whereas the excitatory inputs showed little selectivity. In addition, we found that excitatory currents evoked by a stimulus moving in the preferred direction occurred before the inhibitory currents whereas a stimulus moving in the null direction evoked currents in the reverse temporal order. The membrane potential modulations resulting from these currents were enhanced by the spike generation mechanism to generate amplified direction selectivity in the spike output. Thus our results implicate a local inhibitory circuit in generating direction selectivity in tectal neurons.

  4. Injury-induced ctgfa directs glial bridging and spinal cord regeneration in zebrafish

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    Mokalled, Mayssa H.; Patra, Chinmoy; Dickson, Amy L.; Endo, Toyokazu; Stainier, Didier Y. R.; Poss, Kenneth D.

    2016-01-01

    Unlike mammals, zebrafish efficiently regenerate functional nervous system tissue after major spinal cord injury. Whereas glial scarring presents a roadblock for mammalian spinal cord repair, glial cells in zebrafish form a bridge across severed spinal cord tissue and facilitate regeneration, a relatively unexplored process. Here, we performed a genome-wide profiling screen for secreted factors that are upregulated during zebrafish spinal cord regeneration. We find that connective tissue growth factor a (ctgfa) is induced in and around glial cells that participate in initial bridging events. Mutations in ctgfa disrupt spinal cord repair, while transgenic ctgfa overexpression and local human CTGF recombinant protein delivery accelerate bridging and functional regeneration. Our study reveals that CTGF is necessary and sufficient to stimulate glial bridging and natural spinal cord regeneration. PMID:27811277

  5. Directional cell migration establishes the axes of planar polarity in the posterior lateral-line organ of the zebrafish.

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    López-Schier, Hernán; Starr, Catherine J; Kappler, James A; Kollmar, Richard; Hudspeth, A J

    2004-09-01

    The proper orientation of mechanosensory hair cells along the lateral-line organ of a fish or amphibian is essential for the animal's ability to sense directional water movements. Within the sensory epithelium, hair cells are polarized in a stereotyped manner, but the mechanisms that control their alignment relative to the body axes are unknown. We have found, however, that neuromasts can be oriented either parallel or perpendicular to the anteroposterior body axis. By characterizing the strauss mutant zebrafish line and by tracking labeled cells, we have demonstrated that neuromasts of these two orientations originate from, respectively, the first and second primordia. Furthermore, altering the migratory pathway of a primordium reorients a neuromast's axis of planar polarity. We propose that the global orientation of hair cells relative to the body axes is established through an interaction between directional movement by primordial cells and the timing of neuromast maturation.

  6. Differential Toxicity of mDia Formin-Directed Functional Agonists and Antagonists in Developing Zebrafish

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    Hunter LeCorgne

    2018-04-01

    Full Text Available The mammalian Diaphanous-related (mDia formins are cytoskeletal regulators that assemble and, in some cases, bundle filamentous actin (F-actin, as well as stabilize microtubules. The development of small molecule antagonists and agonists that interrogate mDia formin function has allowed us to investigate the roles of formins in disease states. A small molecule inhibitor of FH2 domain (SMIFH2 inhibits mDia-dependent actin dynamics and abrogates tumor cell migration and cell division in vitro and ex vivo tissue explants. mDia formin activation with small molecule intramimics IMM01/02 and mDia2-DAD peptides inhibited glioblastoma motility and invasion in vitro and ex vivo rat brain slices. However, SMIFH2, IMMs, and mDia2 DAD efficacy in vivo remains largely unexplored and potential toxicity across a range of developmental phenotypes has not been thoroughly characterized. In this study, we performed an in vivo screen of early life-stage toxicity in Danio rerio zebrafish embryos 2 days post-fertilization (dpf in response to SMIFH2, IMM01/02, and mDia2 DAD. SMIFH2 at concentrations ≥5–10 μM induced significant defects in developing zebrafish, including shorter body lengths, tail curvature and defective tail cellularity, craniofacial malformations, pericardial edema, absent and/or compromised vasculature function and flow, depressed heart rates and increased mortality. Conversely, IMM and mDia2 DAD peptides were minimally toxic at concentrations up to 10–20 and 50 μM, respectively. SMIFH2's therapeutic potential may therefore be limited by its substantial in vivo toxicity at functional concentrations. mDia formin agonism with IMMs and mDia2 DADs may therefore be a more effective and less toxic anti-invasive therapeutic approach.

  7. Thymol and Carvacrol Affect Hybrid Tilapia through the Combination of Direct Stimulation and an Intestinal Microbiota-Mediated Effect: Insights from a Germ-Free Zebrafish Model.

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    Ran, Chao; Hu, Jun; Liu, Wenshu; Liu, Zhi; He, Suxu; Dan, Bui Chau Truc; Diem, Nguyen Ngoc; Ooi, Ei Lin; Zhou, Zhigang

    2016-05-01

    Essential oils (EOs) are commonly used as animal feed additives. Information is lacking on the mechanisms driving the beneficial effects of EOs in animals, especially the role played by the intestinal microbiota of the host. The purpose of this study was to clarify the relative contribution of direct effects of EOs on the physiology and immune system of tilapia and indirect effects mediated by the intestinal microbiota by using a germ-free zebrafish model. Juvenile hybrid tilapia were fed a control diet or 1 of 4 treatment diets containing 60-800 mg Next Enhance 150 (NE) (an EO product containing equal levels of thymol and carvacrol)/kg for 6 wk. The key humoral and cellular innate immune parameters were evaluated after the feeding period. In another experiment, the gut microbiota of tilapia fed a control or an NE diet (200 mg/kg) for 2 wk were transferred to 3-d postfertilization (dpf) germ-free (GF) zebrafish, and the expression of genes involved in innate immunity and tight junctions was evaluated in zebrafish at 6 dpf. Lastly, NE was directly applied to 3-dpf GF zebrafish at 3 doses ranging from 0.2 to 20 mg/L, and the direct effect of NE on zebrafish was evaluated after 1 and 3 d. NE supplementation at 200 mg/kg enhanced phagocytosis activity of head kidney macrophages (×1.36) (P tilapia compared with the control (P tilapia through a combination of factors, i.e., primarily through a direct effect on host tissue (immune-stimulating) but also an indirect effect mediated by microbial changes (immune-relieving). © 2016 American Society for Nutrition.

  8. Zebrafish hoxd4a acts upstream of meis1.1 to direct vasculogenesis, angiogenesis and hematopoiesis.

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    Aseervatham Anusha Amali

    Full Text Available Mice lacking the 4th-group paralog Hoxd4 display malformations of the anterior vertebral column, but are viable and fertile. Here, we report that zebrafish embryos having decreased function of the orthologous hoxd4a gene manifest striking perturbations in vasculogenesis, angiogenesis and primitive and definitive hematopoiesis. These defects are preceded by reduced expression of the hemangioblast markers scl1, lmo2 and fli1 within the posterior lateral plate mesoderm (PLM at 13 hours post fertilization (hpf. Epistasis analysis revealed that hoxd4a acts upstream of meis1.1 but downstream of cdx4 as early as the shield stage in ventral-most mesoderm fated to give rise to hemangioblasts, leading us to propose that loss of hoxd4a function disrupts hemangioblast specification. These findings place hoxd4a high in a genetic hierarchy directing hemangioblast formation downstream of cdx1/cdx4 and upstream of meis1.1. An additional consequence of impaired hoxd4a and meis1.1 expression is the deregulation of multiple Hox genes implicated in vasculogenesis and hematopoiesis which may further contribute to the defects described here. Our results add to evidence implicating key roles for Hox genes in their initial phase of expression early in gastrulation.

  9. Zebrafish swimming in the flow: a particle image velocimetry study

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    Violet Mwaffo

    2017-11-01

    Full Text Available Zebrafish is emerging as a species of choice for the study of a number of biomechanics problems, including balance development, schooling, and neuromuscular transmission. The precise quantification of the flow physics around swimming zebrafish is critical toward a mechanistic understanding of the complex swimming style of this fresh-water species. Although previous studies have elucidated the vortical structures in the wake of zebrafish swimming in placid water, the flow physics of zebrafish swimming against a water current remains unexplored. In an effort to illuminate zebrafish swimming in a dynamic environment reminiscent of its natural habitat, we experimentally investigated the locomotion and hydrodynamics of a single zebrafish swimming in a miniature water tunnel using particle image velocimetry. Our results on zebrafish locomotion detail the role of flow speed on tail beat undulations, heading direction, and swimming speed. Our findings on zebrafish hydrodynamics offer a precise quantification of vortex shedding during zebrafish swimming and demonstrate that locomotory patterns play a central role on the flow physics. This knowledge may help clarify the evolutionary advantage of burst and cruise swimming movements in zebrafish.

  10. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture

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    Trivedi, Chintan A.; Bollmann, Johann H.

    2013-01-01

    Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach, and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed toward the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback. PMID:23675322

  11. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture

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    Chintan A Trivedi

    2013-05-01

    Full Text Available Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed towards the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim-triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  12. Effect-directed analysis for estrogenic compounds in a fluvial sediment sample using transgenic cyp19a1b-GFP zebrafish embryos.

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    Fetter, Eva; Krauss, Martin; Brion, François; Kah, Olivier; Scholz, Stefan; Brack, Werner

    2014-09-01

    Xenoestrogens may persist in the environment by binding to sediments or suspended particulate matter serving as long-term reservoir and source of exposure, particularly for organisms living in or in contact with sediments. In this study, we present for the first time an effect-directed analysis (EDA) for identifying estrogenic compounds in a sediment sample using embryos of a transgenic reporter fish strain. In the tg(cyp19a1b-GFP) transgenic zebrafish strain, the expression of GFP (green fluorescent protein) in the brain is driven by an oestrogen responsive element in the promoter of the cyp19a1b (aromatase) gene. The selected sediment sample of the Czech river Bilina had already been analysed in a previous EDA using the yeast oestrogen screening assay and had revealed fractions containing estrogenic compounds. When normal phase HPLC (high performance liquid chromatography) fractionation was used for the separation of the sediment sample, the biotest with transgenic fish embryos revealed two estrogenic fractions. Chemical analysis of candidate compounds in these sediment fractions suggested alkylphenols and estrone as candidate compounds responsible for the observed estrogenic effect. Alkylphenol concentrations could partially explain the estrogenicity of the fractions. However, xenoestrogens below the analytical detection limit or non-targeted estrogenic compounds have probably also contributed to the sample's estrogenic potency. The results indicated the suitability of the tg(cyp19a1b-GFP) fish embryo for an integrated chemical-biological analysis of estrogenic effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Genomic Organization of Zebrafish microRNAs

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    Paydar Ima

    2008-05-01

    Full Text Available Abstract Background microRNAs (miRNAs are small (~22 nt non-coding RNAs that regulate cell movement, specification, and development. Expression of miRNAs is highly regulated, both spatially and temporally. Based on direct cloning, sequence conservation, and predicted secondary structures, a large number of miRNAs have been identified in higher eukaryotic genomes but whether these RNAs are simply a subset of a much larger number of noncoding RNA families is unknown. This is especially true in zebrafish where genome sequencing and annotation is not yet complete. Results We analyzed the zebrafish genome to identify the number and location of proven and predicted miRNAs resulting in the identification of 35 new miRNAs. We then grouped all 415 zebrafish miRNAs into families based on seed sequence identity as a means to identify possible functional redundancy. Based on genomic location and expression analysis, we also identified those miRNAs that are likely to be encoded as part of polycistronic transcripts. Lastly, as a resource, we compiled existing zebrafish miRNA expression data and, where possible, listed all experimentally proven mRNA targets. Conclusion Current analysis indicates the zebrafish genome encodes 415 miRNAs which can be grouped into 44 families. The largest of these families (the miR-430 family contains 72 members largely clustered in two main locations along chromosome 4. Thus far, most zebrafish miRNAs exhibit tissue specific patterns of expression.

  14. Patterns of free calcium in zebrafish embryos

    NARCIS (Netherlands)

    Creton, R; Speksnijder, JE; Jaffe, LF

    Direct knowledge of Ca2+ patterns in vertebrate development is largely restricted to early stages, in which they control fertilization, ooplasmic segregation and cleavage. To explore new roles of Ca2+ in vertebrate development, we injected the Ca2+ indicator aequorin into zebrafish eggs and imaged

  15. Expression of prostaglandin synthases (pgds and pges) during zebrafish gonadal differentiation

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Nielsen, John E; Nielsen, Betina Frydenlund

    2010-01-01

    The present study aimed at elucidating whether the expression pattern of the membrane bound form of prostaglandin E2 synthase (pges) and especially the lipocalin-type prostaglandin D2 synthase (pgds) indicates involvement in gonadal sex differentiation in zebrafish as has previously been found....... In this study, a sexually dimorphic expression of pgds was found in gonads of adult zebrafish with expression in testis but not in ovaries. To determine whether the sex-specific expression pattern of pgds was present in gonads of juvenile zebrafish and therefore could be an early marker of sex in zebrafish, we...... microdissected gonads from four randomly selected individual zebrafish for every second day in the period 2-20 days post hatch (dph) and 0-1 dph. The temporal expression of pgds and pges was investigated in the microdissected gonads, however, no differential expression that could indicate sex-specific difference...

  16. Swimming Effects on Developing Zebrafish

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    Kranenbarg, S.; Pelster, B.

    2013-01-01

    Zebrafish represent an important vertebrate model species in developmental biology. This chapter reviews the effects of exercise on the development of the musculoskeletal system, the cardiovascular system, metabolic capacities of developing zebrafish, and regulation of these processes on the gene

  17. Zebrafish Health Conditions in the China Zebrafish Resource Center and 20 Major Chinese Zebrafish Laboratories.

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    Liu, Liyue; Pan, Luyuan; Li, Kuoyu; Zhang, Yun; Zhu, Zuoyan; Sun, Yonghua

    2016-07-01

    In China, the use of zebrafish as an experimental animal in the past 15 years has widely expanded. The China Zebrafish Resource Center (CZRC), which was established in 2012, is becoming one of the major resource centers in the global zebrafish community. Large-scale use and regular exchange of zebrafish resources have put forward higher requirements on zebrafish health issues in China. This article reports the current aquatic infrastructure design, animal husbandry, and health-monitoring programs in the CZRC. Meanwhile, through a survey of 20 Chinese zebrafish laboratories, we also describe the current health status of major zebrafish facilities in China. We conclude that it is of great importance to establish a widely accepted health standard and health-monitoring strategy in the Chinese zebrafish research community.

  18. A Zebrafish Heart Failure Model for Assessing Therapeutic Agents.

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    Zhu, Xiao-Yu; Wu, Si-Qi; Guo, Sheng-Ya; Yang, Hua; Xia, Bo; Li, Ping; Li, Chun-Qi

    2018-03-20

    Heart failure is a leading cause of death and the development of effective and safe therapeutic agents for heart failure has been proven challenging. In this study, taking advantage of larval zebrafish, we developed a zebrafish heart failure model for drug screening and efficacy assessment. Zebrafish at 2 dpf (days postfertilization) were treated with verapamil at a concentration of 200 μM for 30 min, which were determined as optimum conditions for model development. Tested drugs were administered into zebrafish either by direct soaking or circulation microinjection. After treatment, zebrafish were randomly selected and subjected to either visual observation and image acquisition or record videos under a Zebralab Blood Flow System. The therapeutic effects of drugs on zebrafish heart failure were quantified by calculating the efficiency of heart dilatation, venous congestion, cardiac output, and blood flow dynamics. All 8 human heart failure therapeutic drugs (LCZ696, digoxin, irbesartan, metoprolol, qiliqiangxin capsule, enalapril, shenmai injection, and hydrochlorothiazide) showed significant preventive and therapeutic effects on zebrafish heart failure (p failure model developed and validated in this study could be used for in vivo heart failure studies and for rapid screening and efficacy assessment of preventive and therapeutic drugs.

  19. Molecular genetics of pituitary development in zebrafish.

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    Pogoda, Hans-Martin; Hammerschmidt, Matthias

    2007-08-01

    The pituitary gland of vertebrates consists of two major parts, the neurohypophysis (NH) and the adenohypophysis (AH). As a central part of the hypothalamo-hypophyseal system (HHS), it constitutes a functional link between the nervous and the endocrine system to regulate basic body functions, such as growth, metabolism and reproduction. The development of the AH has been intensively studied in mouse, serving as a model for organogenesis and differential cell specification. However, given that the AH is a relatively recent evolutionary advance of the chordate phylum, it is also interesting to understand its development in lower chordate systems. In recent years, the zebrafish has emerged as a powerful lower vertebrate system for developmental studies, being amenable for large-scale genetic approaches, embryological manipulations, and in vivo imaging. Here, we present an overview of current knowledge of the mechanisms and genetic control of pituitary formation during zebrafish development. First, we describe the components of the zebrafish HHS, and the different pituitary cell types and hormones, followed by a description of the different steps of normal pituitary development. The central part of the review deals with the genes found to be essential for zebrafish AH development, accompanied by a description of the corresponding mutant phenotypes. Finally, we discuss future directions, with particular focus on evolutionary aspects, and some novel functional aspects with growing medical and social relevance.

  20. Ionic channels underlying the ventricular action potential in zebrafish embryo.

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    Alday, Aintzane; Alonso, Hiart; Gallego, Monica; Urrutia, Janire; Letamendia, Ainhoa; Callol, Carles; Casis, Oscar

    2014-06-01

    Over the last years zebrafish has become a popular model in the study of cardiac physiology, pathology and pharmacology. Recently, the application of the 3Rs regulation and the characteristics of the embryo have reduced the use of adult zebrafish use in many studies. However, the zebrafish embryo cardiac physiology is poorly characterized since most works have used indirect techniques and direct recordings of cardiac action potential and ionic currents are scarce. In order to optimize the zebrafish embryo model, we used electrophysiological, pharmacological and immunofluorescence tools to identify the characteristics and the ionic channels involved in the ventricular action potentials of zebrafish embryos. The application of Na(+) or T-type Ca(+2) channel blockers eliminated the cardiac electrical activity, indicating that the action potential upstroke depends on Na(+) and T-type Ca(+2) currents. The plateau phase depends on L-type Ca(+2) channels since it is abolished by specific blockade. The direct channel blockade indicates that the action potential repolarization and diastolic potential depends on ERG K(+) channels. The presence in the embryonic heart of the Nav1.5, Cav1.2, Cav3.2 and ERG channels was also confirmed by immunofluorescence, while the absence of effect of specific blockers and immunostaining indicate that two K(+) repolarizing currents present in human heart, Ito and IKs, are absent in the embryonic zebrafish heart. Our results describe the ionic channels present and its role in the zebrafish embryo heart and support the use of zebrafish embryos to study human diseases and their use for drug testing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Zebrafish models for the functional genomics of neurogenetic disorders.

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    Kabashi, Edor; Brustein, Edna; Champagne, Nathalie; Drapeau, Pierre

    2011-03-01

    In this review, we consider recent work using zebrafish to validate and study the functional consequences of mutations of human genes implicated in a broad range of degenerative and developmental disorders of the brain and spinal cord. Also we present technical considerations for those wishing to study their own genes of interest by taking advantage of this easily manipulated and clinically relevant model organism. Zebrafish permit mutational analyses of genetic function (gain or loss of function) and the rapid validation of human variants as pathological mutations. In particular, neural degeneration can be characterized at genetic, cellular, functional, and behavioral levels. Zebrafish have been used to knock down or express mutations in zebrafish homologs of human genes and to directly express human genes bearing mutations related to neurodegenerative disorders such as spinal muscular atrophy, ataxia, hereditary spastic paraplegia, amyotrophic lateral sclerosis (ALS), epilepsy, Huntington's disease, Parkinson's disease, fronto-temporal dementia, and Alzheimer's disease. More recently, we have been using zebrafish to validate mutations of synaptic genes discovered by large-scale genomic approaches in developmental disorders such as autism, schizophrenia, and non-syndromic mental retardation. Advances in zebrafish genetics such as multigenic analyses and chemical genetics now offer a unique potential for disease research. Thus, zebrafish hold much promise for advancing the functional genomics of human diseases, the understanding of the genetics and cell biology of degenerative and developmental disorders, and the discovery of therapeutics. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. High magnetic field induced otolith fusion in the zebrafish larvae.

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    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-04-11

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an "all-or-none" manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish.

  3. Social dominance modulates eavesdropping in zebrafish

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    Abril-de-Abreu, Rodrigo; Cruz, Ana S.; Oliveira, Rui F.

    2015-01-01

    Group living animals may eavesdrop on signalling interactions between conspecifics and integrate it with their own past social experience in order to optimize the use of relevant information from others. However, little is known about this interplay between public (eavesdropped) and private social information. To investigate it, we first manipulated the dominance status of bystander zebrafish. Next, we either allowed or prevented bystanders from observing a fight. Finally, we assessed their behaviour towards the winners and losers of the interaction, using a custom-made video-tracking system and directional analysis. We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights. Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish. Thus, we show for the first time that zebrafish, a highly social model organism, eavesdrop on conspecific agonistic interactions and that this process is modulated by the eavesdroppers' dominance status. We suggest that this type of integration of public and private information may be ubiquitous in social learning processes. PMID:26361550

  4. Feature Binding in Zebrafish

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    P Neri

    2012-07-01

    Full Text Available Binding operations are primarily ascribed to cortex or similarly complex avian structures. My experiments show that the zebrafish, a lower vertebrate lacking cortex, supports visual feature binding of form and motion for the purpose of social behavior. These results challenge the notion that feature binding may require highly evolved neural structures and demonstrate that the nervous system of lower vertebrates can afford unexpectedly complex computations.

  5. Triclosan Lacks (Anti-Estrogenic Effects in Zebrafish Cells but Modulates Estrogen Response in Zebrafish Embryos

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    Hélène Serra

    2018-04-01

    Full Text Available Triclosan (TCS, an antimicrobial agent widely found in the aquatic environment, is suspected to act as an endocrine disrupting compound, however mechanistic information is lacking in regards to aquatic species. This study assessed the ability of TCS to interfere with estrogen receptor (ER transcriptional activity, in zebrafish-specific in vitro and in vivo reporter gene assays. We report that TCS exhibits a lack of either agonistic or antagonistic effects on a panel of ER-expressing zebrafish (ZELH-zfERα and -zfERβ and human (MELN cell lines. At the organism level, TCS at concentrations of up to 0.3 µM had no effect on ER-regulated brain aromatase gene expression in transgenic cyp19a1b-GFP zebrafish embryos. At a concentration of 1 µM, TCS interfered with the E2 response in an ambivalent manner by potentializing a low E2 response (0.625 nM, but decreasing a high E2 response (10 nM. Altogether, our study suggests that while modulation of ER-regulated genes by TCS may occur in zebrafish, it does so irrespective of a direct binding and activation of zfERs.

  6. Pharmacological Modulation of Hemodynamics in Adult Zebrafish In Vivo.

    Directory of Open Access Journals (Sweden)

    Daniel Brönnimann

    Full Text Available Hemodynamic parameters in zebrafish receive increasing attention because of their important role in cardiovascular processes such as atherosclerosis, hematopoiesis, sprouting and intussusceptive angiogenesis. To study underlying mechanisms, the precise modulation of parameters like blood flow velocity or shear stress is centrally important. Questions related to blood flow have been addressed in the past in either embryonic or ex vivo-zebrafish models but little information is available for adult animals. Here we describe a pharmacological approach to modulate cardiac and hemodynamic parameters in adult zebrafish in vivo.Adult zebrafish were paralyzed and orally perfused with salt water. The drugs isoprenaline and sodium nitroprusside were directly applied with the perfusate, thus closely resembling the preferred method for drug delivery in zebrafish, namely within the water. Drug effects on the heart and on blood flow in the submental vein were studied using electrocardiograms, in vivo-microscopy and mathematical flow simulations.Under control conditions, heart rate, blood flow velocity and shear stress varied less than ± 5%. Maximal chronotropic effects of isoprenaline were achieved at a concentration of 50 μmol/L, where it increased the heart rate by 22.6 ± 1.3% (n = 4; p < 0.0001. Blood flow velocity and shear stress in the submental vein were not significantly increased. Sodium nitroprusside at 1 mmol/L did not alter the heart rate but increased blood flow velocity by 110.46 ± 19.64% (p = 0.01 and shear stress by 117.96 ± 23.65% (n = 9; p = 0.03.In this study, we demonstrate that cardiac and hemodynamic parameters in adult zebrafish can be efficiently modulated by isoprenaline and sodium nitroprusside. Together with the suitability of the zebrafish for in vivo-microscopy and genetic modifications, the methodology described permits studying biological processes that are dependent on hemodynamic alterations.

  7. The Zebrafish Model Organism Database (ZFIN)

    Data.gov (United States)

    U.S. Department of Health & Human Services — ZFIN serves as the zebrafish model organism database. It aims to: a) be the community database resource for the laboratory use of zebrafish, b) develop and support...

  8. Zebrafish: A marvel of high-throughput biology for 21st century toxicology.

    Science.gov (United States)

    Bugel, Sean M; Tanguay, Robert L; Planchart, Antonio

    2014-09-07

    The evolutionary conservation of genomic, biochemical and developmental features between zebrafish and humans is gradually coming into focus with the end result that the zebrafish embryo model has emerged as a powerful tool for uncovering the effects of environmental exposures on a multitude of biological processes with direct relevance to human health. In this review, we highlight advances in automation, high-throughput (HT) screening, and analysis that leverage the power of the zebrafish embryo model for unparalleled advances in our understanding of how chemicals in our environment affect our health and wellbeing.

  9. Immunostaining of dissected zebrafish embryonic heart.

    Science.gov (United States)

    Yang, Jingchun; Xu, Xiaolei

    2012-01-10

    Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. Copyright © 2012 Journal of Visualized Experiments

  10. Object recognition memory in zebrafish.

    Science.gov (United States)

    May, Zacnicte; Morrill, Adam; Holcombe, Adam; Johnston, Travis; Gallup, Joshua; Fouad, Karim; Schalomon, Melike; Hamilton, Trevor James

    2016-01-01

    The novel object recognition, or novel-object preference (NOP) test is employed to assess recognition memory in a variety of organisms. The subject is exposed to two identical objects, then after a delay, it is placed back in the original environment containing one of the original objects and a novel object. If the subject spends more time exploring one object, this can be interpreted as memory retention. To date, this test has not been fully explored in zebrafish (Danio rerio). Zebrafish possess recognition memory for simple 2- and 3-dimensional geometrical shapes, yet it is unknown if this translates to complex 3-dimensional objects. In this study we evaluated recognition memory in zebrafish using complex objects of different sizes. Contrary to rodents, zebrafish preferentially explored familiar over novel objects. Familiarity preference disappeared after delays of 5 mins. Leopard danios, another strain of D. rerio, also preferred the familiar object after a 1 min delay. Object preference could be re-established in zebra danios by administration of nicotine tartrate salt (50mg/L) prior to stimuli presentation, suggesting a memory-enhancing effect of nicotine. Additionally, exploration biases were present only when the objects were of intermediate size (2 × 5 cm). Our results demonstrate zebra and leopard danios have recognition memory, and that low nicotine doses can improve this memory type in zebra danios. However, exploration biases, from which memory is inferred, depend on object size. These findings suggest zebrafish ecology might influence object preference, as zebrafish neophobia could reflect natural anti-predatory behaviour. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

    Science.gov (United States)

    Heap, Lucy A.; Vanwalleghem, Gilles C.; Thompson, Andrew W.; Favre-Bulle, Itia; Rubinsztein-Dunlop, Halina; Scott, Ethan K.

    2018-01-01

    The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH) to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC)/stratum griseum periventriculare (SPV), and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil. PMID:29403362

  12. Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

    Directory of Open Access Journals (Sweden)

    Lucy A. Heap

    2018-01-01

    Full Text Available The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC/stratum griseum periventriculare (SPV, and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil.

  13. Arsenic transport by zebrafish aquaglyceroporins

    Directory of Open Access Journals (Sweden)

    Landfear Scott M

    2009-11-01

    Full Text Available Abstract Background Arsenic is one of the most ubiquitous toxins and endangers the health of tens of millions of humans worldwide. It is a mainly a water-borne contaminant. Inorganic trivalent arsenic (AsIII is one of the major species that exists environmentally. The transport of AsIII has been studied in microbes, plants and mammals. Members of the aquaglyceroporin family have been shown to actively conduct AsIII and its organic metabolite, monomethylarsenite (MAsIII. However, the transport of AsIII and MAsIII in in any fish species has not been characterized. Results In this study, five members of the aquaglyceroporin family from zebrafish (Danio rerio were cloned, and their ability to transport water, glycerol, and trivalent arsenicals (AsIII and MAsIII and antimonite (SbIII was investigated. Genes for at least seven aquaglyceroporins have been annotated in the zebrafish genome project. Here, five genes which are close homologues to human AQP3, AQP9 and AQP10 were cloned from a zebrafish cDNA preparation. These genes were named aqp3, aqp3l, aqp9a, aqp9b and aqp10 according to their similarities to the corresponding human AQPs. Expression of aqp9a, aqp9b, aqp3, aqp3l and aqp10 in multiple zebrafish organs were examined by RT-PCR. Our results demonstrated that these aquaglyceroporins exhibited different tissue expression. They are all detected in more than one tissue. The ability of these five aquaglyceroporins to transport water, glycerol and the metalloids arsenic and antimony was examined following expression in oocytes from Xenopus leavis. Each of these channels showed substantial glycerol transport at equivalent rates. These aquaglyceroporins also facilitate uptake of inorganic AsIII, MAsIII and SbIII. Arsenic accumulation in fish larvae and in different tissues from adult zebrafish was studied following short-term arsenic exposure. The results showed that liver is the major organ of arsenic accumulation; other tissues such as gill, eye

  14. Period 2 Mutation Accelerates ApcMin/+ Tumorigenesis

    Science.gov (United States)

    Wood, Patricia A.; Yang, Xiaoming; Taber, Andrew; Oh, Eun-Young; Ansell, Christine; Ayers, Stacy E.; Al-Assaad, Ziad; Carnevale, Kevin; Berger, Franklin G.; Peña, Maria Marjorette O.; Hrushesky, William J.M.

    2014-01-01

    Colorectal cancer risk is increased in shift workers with presumed circadian disruption. Intestinal epithelial cell proliferation is gated throughout each day by the circadian clock. Period 2 (Per2) is a key circadian clock gene. Per2 mutant (Per2m/m) mice show an increase in lymphomas and deregulated expression of cyclin D and c-Myc genes that are key to proliferation control. We asked whether Per2 clock gene inactivation would accelerate intestinal and colonic tumorigenesis. The effects of PER2 on cell proliferation and β-catenin were studied in colon cancer cell lines by its down-regulation following RNA interference. The effects of Per2 inactivation in vivo on β-catenin and on intestinal and colonic polyp formation were studied in mice with Per2 mutation alone and in combination with an Apc mutation using polyp-prone ApcMin/+ mice. Down-regulation of PER2 in colon cell lines (HCT116 and SW480) increases β-catenin, cyclin D, and cell proliferation. Down-regulation of β-catenin along with Per2 blocks the increase in cyclin D and cell proliferation. Per2m/m mice develop colonic polyps and show an increase in small intestinal mucosa β-catenin and cyclin D protein levels compared with wild-type mice. ApcMin/+Per2m/m mice develop twice the number of small intestinal and colonic polyps, with more severe anemia and splenomegaly, compared with ApcMin/+ mice. These data suggest that Per2 gene product suppresses tumorigenesis in the small intestine and colon by down-regulation of β-catenin and β-catenin target genes, and this circadian core clock gene may represent a novel target for colorectal cancer prevention and control. PMID:19010825

  15. A Student Team in a University of Michigan Biomedical Engineering Design Course Constructs a Microfluidic Bioreactor for Studies of Zebrafish Development

    Science.gov (United States)

    Shen, Yu-chi; Li, David; Al-Shoaibi, Ali; Bersano-Begey, Tom; Chen, Hao; Ali, Shahid; Flak, Betsy; Perrin, Catherine; Winslow, Max; Shah, Harsh; Ramamurthy, Poornapriya; Schmedlen, Rachael H.; Takayama, Shuichi

    2009-01-01

    Abstract The zebrafish is a valuable model for teaching developmental, molecular, and cell biology; aquatic sciences; comparative anatomy; physiology; and genetics. Here we demonstrate that zebrafish provide an excellent model system to teach engineering principles. A seven-member undergraduate team in a biomedical engineering class designed, built, and tested a zebrafish microfluidic bioreactor applying microfluidics, an emerging engineering technology, to study zebrafish development. During the semester, students learned engineering and biology experimental design, chip microfabrication, mathematical modeling, zebrafish husbandry, principles of developmental biology, fluid dynamics, microscopy, and basic molecular biology theory and techniques. The team worked to maximize each person's contribution and presented weekly written and oral reports. Two postdoctoral fellows, a graduate student, and three faculty instructors coordinated and directed the team in an optimal blending of engineering, molecular, and developmental biology skill sets. The students presented two posters, including one at the Zebrafish meetings in Madison, Wisconsin (June 2008). PMID:19292670

  16. Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

    OpenAIRE

    Baars, Destiny L.; Takle, Kendra A.; Heier, Jonathon; Pelegri, Francisco

    2016-01-01

    Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole...

  17. Modeling Myeloid Malignancies Using Zebrafish

    Directory of Open Access Journals (Sweden)

    Kathryn S. Potts

    2017-12-01

    Full Text Available Human myeloid malignancies represent a substantial disease burden to individuals, with significant morbidity and death. The genetic underpinnings of disease formation and progression remain incompletely understood. Large-scale human population studies have identified a high frequency of potential driver mutations in spliceosomal and epigenetic regulators that contribute to malignancies, such as myelodysplastic syndromes (MDS and leukemias. The high conservation of cell types and genes between humans and model organisms permits the investigation of the underlying mechanisms of leukemic development and potential therapeutic testing in genetically pliable pre-clinical systems. Due to the many technical advantages, such as large-scale screening, lineage-tracing studies, tumor transplantation, and high-throughput drug screening approaches, zebrafish is emerging as a model system for myeloid malignancies. In this review, we discuss recent advances in MDS and leukemia using the zebrafish model.

  18. Skin too thin? The developing utility of zebrafish skin (neuro)pharmacology for CNS drug discovery research.

    Science.gov (United States)

    Nguyen, Michael; Poudel, Manoj K; Stewart, Adam Michael; Kalueff, Allan V

    2013-09-01

    Skin coloration can be affected by many genetic, environmental and pharmacological factors. Zebrafish (Danio rerio) are a useful and versatile model organism in biomedical research due to their genetic tractability, physiological homology to mammals, low cost, reproducibility and high throughput. Zebrafish coloration is mediated by chromatophores - the skin color pigment cells largely controlled by endocrine and neural mechanisms. The characteristic darkening of zebrafish skin is caused by the dispersion (and paling - by aggregation) of melanosomes (pigment-containing organelles), which show high homology to mammalian structures. Various pharmacological agents potently affect zebrafish coloration - the phenotype that often accompanies behavioral effects of the drugs, and may be used for drug discovery. Although zebrafish behavior and skin responses are usually not directly related, they share common regulatory (neural, endocrine) mechanisms, and therefore may be assessed in parallel during psychotropic drug screening. For example, some psychoactive drugs can potently affect zebrafish skin coloration. Can we use this knowledge to refine phenotype-driven psychotropic drug discovery? Here, we present current models using zebrafish skin coloration assays, and discuss how these models may be applied to enhance in vivo CNS drug discovery. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Husebye Harald

    2002-08-01

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

  20. The importance of Zebrafish in biomedical research.

    Science.gov (United States)

    Tavares, Bárbara; Santos Lopes, Susana

    2013-01-01

    Zebrafish (Danio rerio) is an ideal model organism for the study of vertebrate development. This is due to the large clutches that each couple produces, with up to 200 embryos every 7 days, and to the fact that the embryos and larvae are small, transparent and undergo rapid external development. Using scientific literature research tools available online and the keywords Zebrafish, biomedical research, human disease, and drug screening, we reviewed original studies and reviews indexed in PubMed. In this review we summarized work conducted with this model for the advancement of our knowledge related to several human diseases. We also focused on the biomedical research being performed in Portugal with the zebrafish model. Powerful live imaging and genetic tools are currently available for zebrafish making it a valuable model in biomedical research. The combination of these properties with the optimization of automated systems for drug screening has transformed the zebrafish into "a top model" in biomedical research, drug discovery and toxicity testing. Furthermore, with the optimization of xenografts technology it will be possible to use zebrafish to aide in the choice of the best therapy for each patient. Zebrafish is an excellent model organism in biomedical research, drug development and in clinical therapy.

  1. 2017 Midwest Zebrafish Meeting Report.

    Science.gov (United States)

    Sandquist, Elizabeth; Petersen, Sarah C; Smith, Cody J

    2017-12-01

    The 2017 Midwest Zebrafish meeting was held from June 16 to 18 at the University of Cincinnati, sponsored by the Cincinnati Children's Hospital Divisions of Developmental Biology, Molecular Cardiovascular Biology, and Gastroenterology, Hepatology, and Nutrition. The meeting, organized by Saulius Sumanas, Joshua Waxman, and Chunyue Yin, hosted >130 attendees from 16 different states. Scientific sessions were focused on morphogenesis, neural development, novel technologies, and disease models, with Steve Ekker, Stephen Potter, and Lila Solnica-Krezel presenting keynote talks. In this article, we highlight the results and emerging themes from the meeting.

  2. Sprouting Buds of Zebrafish Research in Malaysia: First Malaysia Zebrafish Disease Model Workshop.

    Science.gov (United States)

    Okuda, Kazuhide Shaun; Tan, Pei Jean; Patel, Vyomesh

    2016-04-01

    Zebrafish is gaining prominence as an important vertebrate model for investigating various human diseases. Zebrafish provides unique advantages such as optical clarity of embryos, high fecundity rate, and low cost of maintenance, making it a perfect complement to the murine model equivalent in biomedical research. Due to these advantages, researchers in Malaysia are starting to take notice and incorporate the zebrafish model into their research activities. However, zebrafish research in Malaysia is still in its infancy stage and many researchers still remain unaware of the full potential of the zebrafish model or have limited access to related tools and techniques that are widely utilized in many zebrafish laboratories worldwide. To overcome this, we organized the First Malaysia Zebrafish Disease Model Workshop in Malaysia that took place on 11th and 12th of November 2015. In this workshop, we showcased how the zebrafish model is being utilized in the biomedical field in international settings as well as in Malaysia. For this, notable international speakers and those from local universities known to be carrying out impactful research using zebrafish were invited to share some of the cutting edge techniques that are used in their laboratories that may one day be incorporated in the Malaysian scientific community.

  3. Imaging a seizure model in zebrafish with structured illumination light sheet microscopy

    Science.gov (United States)

    Liu, Yang; Dale, Savannah; Ball, Rebecca; VanLeuven, Ariel J.; Baraban, Scott; Sornborger, Andrew; Lauderdale, James D.; Kner, Peter

    2018-02-01

    Zebrafish are a promising vertebrate model for elucidating how neural circuits generate behavior under normal and pathological conditions. The Baraban group first demonstrated that zebrafish larvae are valuable for investigating seizure events and can be used as a model for epilepsy in humans. Because of their small size and transparency, zebrafish embryos are ideal for imaging seizure activity using calcium indicators. Light-sheet microscopy is well suited to capturing neural activity in zebrafish because it is capable of optical sectioning, high frame rates, and low excitation intensities. We describe work in our lab to use light-sheet microscopy for high-speed long-time imaging of neural activity in wildtype and mutant zebrafish to better understand the connectivity and activity of inhibitory neural networks when GABAergic signaling is altered in vivo. We show that, with light-sheet microscopy, neural activity can be recorded at 23 frames per second in twocolors for over 10 minutes allowing us to capture rare seizure events in mutants. We have further implemented structured illumination to increase resolution and contrast in the vertical and axial directions during high-speed imaging at an effective frame rate of over 7 frames per second.

  4. Colonizing the embryonic zebrafish gut with anaerobic bacteria derived from the human gastrointestinal tract.

    Science.gov (United States)

    Toh, Michael C; Goodyear, Mara; Daigneault, Michelle; Allen-Vercoe, Emma; Van Raay, Terence J

    2013-06-01

    The zebrafish has become increasingly popular for microbiological research. It has been used as an infection model for a variety of pathogens, and is also emerging as a tool for studying interactions between a host and its resident microbial communities. The mouse microbiota has been transplanted into the zebrafish gut, but to our knowledge, there has been no attempt to introduce a bacterial community derived from the human gut. We explored two methods for colonizing the developing gut of 5-day-old germ-free zebrafish larvae with a defined anaerobic microbial community derived from a single human fecal sample. Both environmental exposure (static immersion) and direct microinjection into the gut resulted in the establishment of two species-Lactobacillus paracasei and Eubacterium limosum-from a community of 30 strains consisting of 22 anaerobic species. Of particular interest is E. limosum, which, as a strict anaerobe, represents a group of bacteria which until now have not been shown to colonize the developing zebrafish gut. Our success here indicates that further investigation of zebrafish as a tool for studying human gut microbial communities is warranted.

  5. A review of monoaminergic neuropsychopharmacology in zebrafish.

    Science.gov (United States)

    Maximino, Caio; Herculano, Anderson Manoel

    2010-12-01

    Monoamine neurotransmitters are the major regulatory mechanisms in the vertebrate brain, involved in the adjustment of motivation, emotion, and cognition. The chemical anatomy of these systems is thought to be highly conserved in the brain of all vertebrates, including zebrafish. Recently, the development of behavioral assays in zebrafish allowed the neuropsychopharmacological investigation of these circuits and its functions. Here we review neuroanatomical, genetic, neurochemical, and psychopharmacological evidence regarding the roles of histaminergic, dopaminergic, noradrenergic, serotonergic, and melatonergic systems in this species. We conclude that, in spite of species differences, zebrafish are suitable for the investigation of neuropsychopharmacology of drugs that affect theses systems; nonetheless, more thorough validation of behavioral methods is still needed.

  6. Learning and memory in zebrafish larvae

    Science.gov (United States)

    Roberts, Adam C.; Bill, Brent R.; Glanzman, David L.

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory. PMID:23935566

  7. Episodic-like memory in zebrafish.

    Science.gov (United States)

    Hamilton, Trevor J; Myggland, Allison; Duperreault, Erika; May, Zacnicte; Gallup, Joshua; Powell, Russell A; Schalomon, Melike; Digweed, Shannon M

    2016-11-01

    Episodic-like memory tests often aid in determining an animal's ability to recall the what, where, and which (context) of an event. To date, this type of memory has been demonstrated in humans, wild chacma baboons, corvids (Scrub jays), humming birds, mice, rats, Yucatan minipigs, and cuttlefish. The potential for this type of memory in zebrafish remains unexplored even though they are quickly becoming an essential model organism for the study of a variety of human cognitive and mental disorders. Here we explore the episodic-like capabilities of zebrafish (Danio rerio) in a previously established mammalian memory paradigm. We demonstrate that when zebrafish were presented with a familiar object in a familiar context but a novel location within that context, they spend more time in the novel quadrant. Thus, zebrafish display episodic-like memory as they remember what object they saw, where they saw it (quadrant location), and on which occasion (yellow or blue walls) it was presented.

  8. Identification and characterization of zebrafish thrombocytes.

    Science.gov (United States)

    Jagadeeswaran, P; Sheehan, J P; Craig, F E; Troyer, D

    1999-12-01

    To analyse primary haemostasis in the zebrafish we have identified and characterized the zebrafish thrombocyte by morphologic, immunologic and functional approaches. Novel methods were developed for harvesting zebrafish blood with preservation of thrombocytes, and assaying whole blood adhesion/aggregation responses in microtitre plates. Light and electron microscopy of the thrombocyte illustrated morphological characteristics including the formation of aggregates, pseudopodia, and surface-connected vesicles analagous to the platelet canalicular system. Immunostaining with polyclonal antisera versus human platelet glycoproteins demonstrated the presence of glycoprotein Ib and IIb/IIIa-like complexes on the thrombocyte surface. Whole blood assays for adhesion/aggregation and ATP release showed ristocetin-induced adhesion without ATP release, and platelet agonist (collagen, arachidonic acid) induced aggregation with ATP release. Blood harvested from zebrafish treated with aspirin demonstrated inhibition of arachidonic acid induced aggregation and agonist induced ATP release, consistent with at least partial dependence on an intact cyclo oxygenase pathway. The combined morphologic immunologic and functional evidence suggest that the zebrafish thrombocyte is the haemostatic homologue of the mammalian platelet. Conservation of major haemostatic pathways involved in platelet function and coagulation suggests that the zebrafish is a relevant model for mammalian haemostasis and thrombosis.

  9. Influence of magnetic field on zebrafish activity and orientation in a plus maze.

    Science.gov (United States)

    Osipova, Elena A; Pavlova, Vera V; Nepomnyashchikh, Valentin A; Krylov, Viacheslav V

    2016-01-01

    We describe an impact of the geomagnetic field (GMF) and its modification on zebrafish's orientation and locomotor activity in a plus maze with four arms oriented to the north, east, south and west. Zebrafish's directional preferences were bimodal in GMF: they visited two arms oriented in opposed directions (east-west) most frequently. This bimodal preference remained stable for same individuals across experiments divided by several days. When the horizontal GMF component was turned 90° clockwise, the preference accordingly shifted by 90° to arms oriented to the north and south. Other modifications of GMF (reversal of both vertical and horizontal GMF components; reversal of vertical component only; and reversal of horizontal component only) did not exert any discernible effect on the orientation of zebrafish. The 90° turn of horizontal component also resulted in a significant increase of fish's locomotor activity in comparison with the natural GMF. This increase became even more pronounced when the horizontal component was repeatedly turned by 90° and back with 1min interval between turns. Our results show that GMF and its variations should be taken into account when interpreting zebrafish's directional preferences and locomotor activity in mazes and other experimental devices. Copyright © 2015. Published by Elsevier B.V.

  10. Zebrafish neurobehavioral phenomics for aquatic neuropharmacology and toxicology research.

    Science.gov (United States)

    Kalueff, Allan V; Echevarria, David J; Homechaudhuri, Sumit; Stewart, Adam Michael; Collier, Adam D; Kaluyeva, Aleksandra A; Li, Shaomin; Liu, Yingcong; Chen, Peirong; Wang, JiaJia; Yang, Lei; Mitra, Anisa; Pal, Subharthi; Chaudhuri, Adwitiya; Roy, Anwesha; Biswas, Missidona; Roy, Dola; Podder, Anupam; Poudel, Manoj K; Katare, Deepshikha P; Mani, Ruchi J; Kyzar, Evan J; Gaikwad, Siddharth; Nguyen, Michael; Song, Cai

    2016-01-01

    Zebrafish (Danio rerio) are rapidly emerging as an important model organism for aquatic neuropharmacology and toxicology research. The behavioral/phenotypic complexity of zebrafish allows for thorough dissection of complex human brain disorders and drug-evoked pathological states. As numerous zebrafish models become available with a wide spectrum of behavioral, genetic, and environmental methods to test novel drugs, here we discuss recent zebrafish phenomics methods to facilitate drug discovery, particularly in the field of biological psychiatry. Additionally, behavioral, neurological, and endocrine endpoints are becoming increasingly well-characterized in zebrafish, making them an inexpensive, robust and effective model for toxicology research and pharmacological screening. We also discuss zebrafish behavioral phenotypes, experimental considerations, pharmacological candidates and relevance of zebrafish neurophenomics to other 'omics' (e.g., genomic, proteomic) approaches. Finally, we critically evaluate the limitations of utilizing this model organism, and outline future strategies of research in the field of zebrafish phenomics. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Neutron induced bystander effect among zebrafish embryos

    Science.gov (United States)

    Ng, C. Y. P.; Kong, E. Y.; Kobayashi, A.; Suya, N.; Uchihori, Y.; Cheng, S. H.; Konishi, T.; Yu, K. N.

    2015-12-01

    The present paper reported the first-ever observation of neutron induced bystander effect (NIBE) using zebrafish (Danio rerio) embryos as the in vivo model. The neutron exposure in the present work was provided by the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility at the National Institute of Radiological Sciences (NIRS), Chiba, Japan. Two different strategies were employed to induce NIBE, namely, through directly partnering and through medium transfer. Both results agreed with a neutron-dose window (20-50 mGy) which could induce NIBE. The lower dose limit corresponded to the threshold amount of neutron-induced damages to trigger significant bystander signals, while the upper limit corresponded to the onset of gamma-ray hormesis which could mitigate the neutron-induced damages and thereby suppress the bystander signals. Failures to observe NIBE in previous studies were due to using neutron doses outside the dose-window. Strategies to enhance the chance of observing NIBE included (1) use of a mono-energetic high-energy (e.g., between 100 keV and 2 MeV) neutron source, and (2) use of a neutron source with a small gamma-ray contamination. It appeared that the NASBEE facility used in the present study fulfilled both conditions, and was thus ideal for triggering NIBE.

  12. Developmental effects of aerosols and coal burning particles in zebrafish embryos

    International Nuclear Information System (INIS)

    Olivares, Alba; Drooge, Barend L. van; Casado, Marta; Prats, Eva; Serra, Montserrat; Ven, Leo T. van der; Kamstra, Jorke H.; Hamers, Timo; Hermsen, Sanne; Grimalt, Joan O.; Piña, Benjamin

    2013-01-01

    Embryo toxicity of particles generated by combustion processes is of special concern for human health. A significant part of these toxic effects is linked to the binding of some pollutants (like polycyclic aromatic hydrocarbons or PAHs) to the Aryl hydrocarbon Receptor (AhR) and the activation of target genes, like the cytochrome P4501A. This activity was analyzed for ambient air and coal-combustion particle extracts in zebrafish embryos (the cyp1aDarT assay) and in two single-cell bioassays: the yeast-based YCM-RYA and the DR-luc (rat cells) assay. Observed AhR ligand activity of samples generally correlated to the predicted toxic effect according to their PAH composition, except for one of the coal combustion samples with an anomalously high activity in the cyp1aDarT assay. This sample induced deformities in zebrafish embryos. We concluded that the combination of morphological and molecular assays may detect embryonic toxic effects that cannot be predicted from chemical analyses or single-cell bioassays. -- Highlights: ► Samples from air particulated matter and coal waste gob showed embryo toxicity in zebrafish. ► PAHs composition of samples does not adequately predict the toxic effects in zebrafish. ► Active coal waste gob samples show maximal AhR-ligand activity and induce deformations in zebrafish embryos. -- Aerosols and coal burning particles showed a strong developmental toxicity in zebrafish, in a degree that cannot be directly predicted from chemical analyses or single-cell bioassays

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

    Directory of Open Access Journals (Sweden)

    Cheng Shuk

    2009-02-01

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

  14. Evaluating human cancer cell metastasis in zebrafish

    International Nuclear Information System (INIS)

    Teng, Yong; Xie, Xiayang; Walker, Steven; White, David T; Mumm, Jeff S; Cowell, John K

    2013-01-01

    In vivo metastasis assays have traditionally been performed in mice, but the process is inefficient and costly. However, since zebrafish do not develop an adaptive immune system until 14 days post-fertilization, human cancer cells can survive and metastasize when transplanted into zebrafish larvae. Despite isolated reports, there has been no systematic evaluation of the robustness of this system to date. Individual cell lines were stained with CM-Dil and injected into the perivitelline space of 2-day old zebrafish larvae. After 2-4 days fish were imaged using confocal microscopy and the number of metastatic cells was determined using Fiji software. To determine whether zebrafish can faithfully report metastatic potential in human cancer cells, we injected a series of cells with different metastatic potential into the perivitelline space of 2 day old embryos. Using cells from breast, prostate, colon and pancreas we demonstrated that the degree of cell metastasis in fish is proportional to their invasion potential in vitro. Highly metastatic cells such as MDA231, DU145, SW620 and ASPC-1 are seen in the vasculature and throughout the body of the fish after only 24–48 hours. Importantly, cells that are not invasive in vitro such as T47D, LNCaP and HT29 do not metastasize in fish. Inactivation of JAK1/2 in fibrosarcoma cells leads to loss of invasion in vitro and metastasis in vivo, and in zebrafish these cells show limited spread throughout the zebrafish body compared with the highly metastatic parental cells. Further, knockdown of WASF3 in DU145 cells which leads to loss of invasion in vitro and metastasis in vivo also results in suppression of metastasis in zebrafish. In a cancer progression model involving normal MCF10A breast epithelial cells, the degree of invasion/metastasis in vitro and in mice is mirrored in zebrafish. Using a modified version of Fiji software, it is possible to quantify individual metastatic cells in the transparent larvae to correlate with

  15. Biosecurity and Health Monitoring at the Zebrafish International Resource Center

    OpenAIRE

    Murray, Katrina N.; Varga, Zolt?n M.; Kent, Michael L.

    2016-01-01

    The Zebrafish International Resource Center (ZIRC) is a repository and distribution center for mutant, transgenic, and wild-type zebrafish. In recent years annual imports of new zebrafish lines to ZIRC have increased tremendously. In addition, after 15 years of research, we have identified some of the most virulent pathogens affecting zebrafish that should be avoided in large production facilities, such as ZIRC. Therefore, while importing a high volume of new lines we prioritize safeguarding ...

  16. Report of Workshop on Euthanasia for Zebrafish-A Matter of Welfare and Science.

    Science.gov (United States)

    Köhler, Almut; Collymore, Chereen; Finger-Baier, Karin; Geisler, Robert; Kaufmann, Larissa; Pounder, Kieran C; Schulte-Merker, Stefan; Valentim, Ana; Varga, Zoltan M; Weiss, Jürgen; Strähle, Uwe

    2017-12-01

    The increasing importance of zebrafish as a biomedical model organism is reflected by the steadily growing number of publications and laboratories working with this species. Regulatory recommendations for euthanasia as issued in Directive 2010/63/EU are, however, based on experience with fish species used for food production and do not take the small size and specific physiology of zebrafish into account. Consequently, the currently recommended methods of euthanasia in the Directive 2010/63/EU are either not applicable or may interfere with research goals. An international workshop was held in Karlsruhe, Germany, March 9, 2017, to discuss and propose alternative methods for euthanasia of zebrafish. The aim was to identify methods that adequately address the physiology of zebrafish and its use as a biomedical research model, follow the principles of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation and consider animal welfare during anesthesia and euthanasia. The results of the workshop are summarized here in the form of a white paper.

  17. Distribution and chronotropic effects of serotonin in the zebrafish heart.

    Science.gov (United States)

    Stoyek, Matthew R; Jonz, Michael G; Smith, Frank M; Croll, Roger P

    2017-09-01

    Several lines of evidence suggest that serotonin (5-HT) has a regulatory role in cardiovascular function from embryogenesis through adulthood. However, the reported actions of 5-HT are often contradictory and include bradycardia or tachycardia, hypotension or hypertension, and vasodilation or vasoconstriction. Clarifying such cardiac effects requires further research and may benefit from utilizing a model simpler than the mammalian hearts traditionally used in these studies. In the present study, we describe the cardiac distribution and chronotropic responses of 5-HT in the zebrafish heart. A combined anatomical, electrophysiological, and pharmacological approach was used to investigate the involvement of 5-HT pathways, and to compare neural and direct myocardial pathways of biological action. Immunohistochemical methods revealed 5-HT in endocardial cells, glial-like cells, and intracardiac neurons in the atrium. Electrocardiogram (ECG) recordings combined with the administration of pharmacological agents demonstrated that 5-HT acted predominantly through direct myocardial pathways resulting in a reduction of heart rate. Overall, the results of this study contribute significant advances in the establishment of the zebrafish as a new model for studies of the role of 5-HT in autonomic cardiac control. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Transcriptome analysis of zebrafish embryogenesis using microarrays.

    Directory of Open Access Journals (Sweden)

    Sinnakaruppan Mathavan

    2005-08-01

    Full Text Available Zebrafish (Danio rerio is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition, a time point earlier than when the zygotic genome was traditionally thought to become active. Here we provide, for the first time to our knowledge, a comprehensive list of developmentally regulated zebrafish genes and their expression profiles during embryogenesis, including novel information on the temporal expression of several thousand previously uncharacterized genes. The expression data generated from this study are accessible to all interested scientists from our institute resource database (http://giscompute.gis.a-star.edu.sg/~govind/zebrafish/data_download.html.

  19. 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.

  20. New tides: using zebrafish to study renal regeneration.

    Science.gov (United States)

    McCampbell, Kristen K; Wingert, Rebecca A

    2014-02-01

    Over the past several decades, the zebrafish has become one of the major vertebrate model organisms used in biomedical research. In this arena, the zebrafish has emerged as an applicable system for the study of kidney diseases and renal regeneration. The relevance of the zebrafish model for nephrology research has been increasingly appreciated as the understanding of zebrafish kidney structure, ontogeny, and the response to damage has steadily expanded. Recent studies have documented the amazing regenerative characteristics of the zebrafish kidney, which include the ability to replace epithelial populations after acute injury and to grow new renal functional units, termed nephrons. Here we discuss how nephron composition is conserved between zebrafish and mammals, and highlight how recent findings from zebrafish studies utilizing transgenic technologies and chemical genetics can complement traditional murine approaches in the effort to dissect how the kidney responds to acute damage and identify therapeutics that enhance human renal regeneration. Copyright © 2014 Mosby, Inc. All rights reserved.

  1. Neutrophil Reverse Migration Becomes Transparent with Zebrafish

    Directory of Open Access Journals (Sweden)

    Taylor W. Starnes

    2012-01-01

    Full Text Available The precise control of neutrophil-mediated inflammation is critical for both host defense and the prevention of immunopathology. In vivo imaging studies in zebrafish, and more recently in mice, have made the novel observation that neutrophils leave a site of inflammation through a process called neutrophil reverse migration. The application of advanced imaging techniques to the genetically tractable, optically transparent zebrafish larvae was critical for these advances. Still, the mechanisms underlying neutrophil reverse migration and its effects on the resolution or priming of immune responses remain unclear. Here, we review the current knowledge of neutrophil reverse migration, its potential roles in host immunity, and the live imaging tools that make zebrafish a valuable model for increasing our knowledge of neutrophil behavior in vivo.

  2. Tributyltin and Zebrafish: Swimming in Dangerous Water

    Directory of Open Access Journals (Sweden)

    Clemilson Berto-Júnior

    2018-04-01

    Full Text Available Zebrafish has been established as a reliable biological model with important insertion in academy (morphologic, biochemical, and pathophysiological studies and pharmaceutical industry (toxicology and drug development due to its molecular complexity and similar systems biology that recapitulate those from other organisms. Considering the toxicological aspects, many efforts using zebrafish models are being done in order to elucidate the effects of endocrine disruptors, and some of them are focused on tributyltin (TBT and its mechanism of action. TBT is an antifouling agent applied in ship’s hull that is constantly released into the water and absorbed by marine organisms, leading to bioaccumulation and biomagnification effects. Thus, several findings of malformations and changes in the normal biochemical and physiologic aspects of these marine animals have been related to TBT contamination. In the present review, we have compiled the most significant studies related to TBT effects in zebrafish, also taking into consideration the effects found in other study models.

  3. Tributyltin and Zebrafish: Swimming in Dangerous Water

    Science.gov (United States)

    Berto-Júnior, Clemilson; de Carvalho, Denise Pires; Soares, Paula; Miranda-Alves, Leandro

    2018-01-01

    Zebrafish has been established as a reliable biological model with important insertion in academy (morphologic, biochemical, and pathophysiological studies) and pharmaceutical industry (toxicology and drug development) due to its molecular complexity and similar systems biology that recapitulate those from other organisms. Considering the toxicological aspects, many efforts using zebrafish models are being done in order to elucidate the effects of endocrine disruptors, and some of them are focused on tributyltin (TBT) and its mechanism of action. TBT is an antifouling agent applied in ship’s hull that is constantly released into the water and absorbed by marine organisms, leading to bioaccumulation and biomagnification effects. Thus, several findings of malformations and changes in the normal biochemical and physiologic aspects of these marine animals have been related to TBT contamination. In the present review, we have compiled the most significant studies related to TBT effects in zebrafish, also taking into consideration the effects found in other study models. PMID:29692757

  4. Culturable gut microbiota diversity in zebrafish.

    Science.gov (United States)

    Cantas, Leon; Sørby, Jan Roger Torp; Aleström, Peter; Sørum, Henning

    2012-03-01

    The zebrafish (Danio rerio) is an increasingly used laboratory animal model in basic biology and biomedicine, novel drug development, and toxicology. The wide use has increased the demand for optimized husbandry protocols to ensure animal health care and welfare. The knowledge about the correlation between culturable zebrafish intestinal microbiota and health in relation to environmental factors and management procedures is very limited. A semi-quantitative level of growth of individual types of bacteria was determined and associated with sampling points. A total of 72 TAB line zebrafish from four laboratories (Labs A-D) in the Zebrafish Network Norway were used. Diagnostic was based on traditional bacterial culture methods and biochemical characterization using commercial kits, followed by 16S rDNA gene sequencing from pure subcultures. Also selected Gram-negative isolates were analyzed for antibiotic susceptibility to 8 different antibiotics. A total of 13 morphologically different bacterial species were the most prevalent: Aeromonas hydrophila, Aeromonas sobria, Vibrio parahaemolyticus, Photobacterium damselae, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas luteola, Comamonas testosteroni, Ochrobactrum anthropi, Staphylococcus cohnii, Staphylococcus epidermidis, Staphylococcus capitis, and Staphylococcus warneri. Only Lab B had significantly higher levels of total bacterial growth (OR=2.03), whereas numbers from Lab C (OR=1.01) and Lab D (OR=1.12) were found to be similar to the baseline Lab A. Sexually immature individuals had a significantly higher level of harvested total bacterial growth than mature fish (OR=0.82), no statistically significant differences were found between male and female fish (OR=1.01), and the posterior intestinal segment demonstrated a higher degree of culturable bacteria than the anterior segment (OR=4.1). Multiple antibiotic (>3) resistance was observed in 17% of the strains. We propose that a rapid conventional

  5. Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio.

    Science.gov (United States)

    Hata, Hiroki; Hori, Michio

    2012-01-01

    The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.

  6. Circadian clocks, rhythmic synaptic plasticity and the sleep-wake cycle in zebrafish.

    Science.gov (United States)

    Elbaz, Idan; Foulkes, Nicholas S; Gothilf, Yoav; Appelbaum, Lior

    2013-01-01

    The circadian clock and homeostatic processes are fundamental mechanisms that regulate sleep. Surprisingly, despite decades of research, we still do not know why we sleep. Intriguing hypotheses suggest that sleep regulates synaptic plasticity and consequently has a beneficial role in learning and memory. However, direct evidence is still limited and the molecular regulatory mechanisms remain unclear. The zebrafish provides a powerful vertebrate model system that enables simple genetic manipulation, imaging of neuronal circuits and synapses in living animals, and the monitoring of behavioral performance during day and night. Thus, the zebrafish has become an attractive model to study circadian and homeostatic processes that regulate sleep. Zebrafish clock- and sleep-related genes have been cloned, neuronal circuits that exhibit circadian rhythms of activity and synaptic plasticity have been studied, and rhythmic behavioral outputs have been characterized. Integration of this data could lead to a better understanding of sleep regulation. Here, we review the progress of circadian clock and sleep studies in zebrafish with special emphasis on the genetic and neuroendocrine mechanisms that regulate rhythms of melatonin secretion, structural synaptic plasticity, locomotor activity and sleep.

  7. Circadian clocks, rhythmic synaptic plasticity and the sleep-wake cycle in zebrafish

    Directory of Open Access Journals (Sweden)

    Idan eElbaz

    2013-02-01

    Full Text Available The circadian clock and homeostatic processes are fundamental mechanisms that regulate sleep. Surprisingly, despite decades of research, we still do not know why we sleep. Intriguing hypotheses suggest that sleep regulates synaptic plasticity and consequently has a beneficial role in learning and memory. However, direct evidence is still limited and the molecular regulatory mechanisms remain unclear. The zebrafish provides a powerful vertebrate model system that enables simple genetic manipulation, imaging of neuronal circuits and synapses in living animals, and the monitoring of behavioral performance during day and night. Thus, the zebrafish has become an attractive model to study circadian and homeostatic processes that regulate sleep. Zebrafish clock- and sleep-related genes have been cloned, neuronal circuits that exhibit circadian rhythms of activity and synaptic plasticity have been studied, and rhythmic behavioral outputs have been characterized. Integration of this data could lead to a better understanding of sleep regulation. Here, we review the progress of circadian clock and sleep studies in zebrafish with special emphasis on the genetic and neuroendocrine mechanisms that regulate rhythms of melatonin secretion, structural synaptic plasticity, locomotor activity and sleep.

  8. Identification and expression analysis of zebrafish glypicans during embryonic development.

    Directory of Open Access Journals (Sweden)

    Mansi Gupta

    Full Text Available Heparan sulfate Proteoglycans (HSPG are ubiquitous molecules with indispensable functions in various biological processes. Glypicans are a family of HSPG's, characterized by a Gpi-anchor which directs them to the cell surface and/or extracellular matrix where they regulate growth factor signaling during development and disease. We report the identification and expression pattern of glypican genes from zebrafish. The zebrafish genome contains 10 glypican homologs, as opposed to six in mammals, which are highly conserved and are phylogenetically related to the mammalian genes. Some of the fish glypicans like Gpc1a, Gpc3, Gpc4, Gpc6a and Gpc6b show conserved synteny with their mammalian cognate genes. Many glypicans are expressed during the gastrulation stage, but their expression becomes more tissue specific and defined during somitogenesis stages, particularly in the developing central nervous system. Existence of multiple glypican orthologs in fish with diverse expression pattern suggests highly specialized and/or redundant function of these genes during embryonic development.

  9. Carbonic anhydrase 5 regulates acid-base homeostasis in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ruben Postel

    Full Text Available The regulation of the acid-base balance in cells is essential for proper cellular homeostasis. Disturbed acid-base balance directly affects cellular physiology, which often results in various pathological conditions. In every living organism, the protein family of carbonic anhydrases regulate a broad variety of homeostatic processes. Here we describe the identification, mapping and cloning of a zebrafish carbonic anhydrase 5 (ca5 mutation, collapse of fins (cof, which causes initially a collapse of the medial fins followed by necrosis and rapid degeneration of the embryo. These phenotypical characteristics can be mimicked in wild-type embryos by acetazolamide treatment, suggesting that CA5 activity in zebrafish is essential for a proper development. In addition we show that CA5 regulates acid-base balance during embryonic development, since lowering the pH can compensate for the loss of CA5 activity. Identification of selective modulators of CA5 activity could have a major impact on the development of new therapeutics involved in the treatment of a variety of disorders.

  10. Structure of period-2 step-1 accelerator island in area preserving maps

    International Nuclear Information System (INIS)

    Hirose, K.; Ichikawa, Y.H.; Saito, S.

    1996-03-01

    Since the multi-periodic accelerator modes manifest their contribution even in the region of small stochastic parameters, analysis of such regular motion appears to be critical to explore the stochastic properties of the Hamiltonian system. Here, structure of period-2 step-1 accelerator mode is analyzed for the systems described by the Harper map and by the standard map. The stability criterions have been analyzed in detail in comparison with numerical analyses. The period-3 squeezing around the period-2 step-1 islands is identified in the standard map. (author)

  11. Dietary β-glucan enhances the contents of complement component 3 and factor B in eggs of zebrafish.

    Science.gov (United States)

    Jiang, Chengyan; Wang, Peng; Li, Mengyang; Liu, Shousheng; Zhang, Shicui

    2016-12-01

    β-glucan has been shown to increase non-specific immunity and resistance against infections or pathogenic bacteria in several fish species, but no information is available regarding its trans-generational effects to date. Here we clearly demonstrated that β-glucan enhanced the contents of immune-relevant molecules C3 and Bf in eggs of zebrafish, and the embryos derived from β-1,3 glucan-treated zebrafish were more resistant to bacterial challenge than control embryos. Moreover, the transferred C3 and Bf were directly associated with the antimicrobial defense of early embryos. In addition, feeding female zebrafish with β-glucan had little detrimental effects on the number of spawned eggs and their embryonic development. Collectively, these data show for the first time that β-glucan can be safely used to promote the non-specific immunity in offspring of fishes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Zebrafish in Toxicology and Environmental Health.

    Science.gov (United States)

    Bambino, Kathryn; Chu, Jaime

    2017-01-01

    As manufacturing processes and development of new synthetic compounds increase to keep pace with the expanding global demand, environmental health, and the effects of toxicant exposure are emerging as critical public health concerns. Additionally, chemicals that naturally occur in the environment, such as metals, have profound effects on human and animal health. Many of these compounds are in the news: lead, arsenic, and endocrine disruptors such as bisphenol A have all been widely publicized as causing disease or damage to humans and wildlife in recent years. Despite the widespread appreciation that environmental toxins can be harmful, there is limited understanding of how many toxins cause disease. Zebrafish are at the forefront of toxicology research; this system has been widely used as a tool to detect toxins in water samples and to investigate the mechanisms of action of environmental toxins and their related diseases. The benefits of zebrafish for studying vertebrate development are equally useful for studying teratogens. Here, we review how zebrafish are being used both to detect the presence of some toxins as well as to identify how environmental exposures affect human health and disease. We focus on areas where zebrafish have been most effectively used in ecotoxicology and in environmental health, including investigation of exposures to endocrine disruptors, industrial waste byproducts, and arsenic. © 2017 Elsevier Inc. All rights reserved.

  13. Visualizing infections and immune mechanisms in zebrafish

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Korbut, Rozalia; Mehrdana, Foojan

    , immunological reactions during e.g. transplant rejections or the spread and pathogenicity of pathogens. We have, in our laboratory, used the zebrafish as a model for aquacultured fish species and their pathogens. We have 1) visualized antigen uptake in vivo following a bath in a soup containing fluorescent...

  14. Highly Efficient ENU Mutagenesis in Zebrafish.

    NARCIS (Netherlands)

    de Bruijn, E.; Cuppen, E.; Feitsma, H.

    2009-01-01

    ENU (N-ethyl-N-nitrosourea) mutagenesis is a widely accepted and proven method to introduce random point mutations in the genome. Because there are no targeted knockout strategies available for zebrafish so far, random mutagenesis is currently the preferred method in both forward and reverse genetic

  15. A zebrafish model of inflammatory lymphangiogenesis

    Directory of Open Access Journals (Sweden)

    Kazuhide S. Okuda

    2015-10-01

    Full Text Available Inflammatory bowel disease (IBD is a disabling chronic inflammatory disease of the gastrointestinal tract. IBD patients have increased intestinal lymphatic vessel density and recent studies have shown that this may contribute to the resolution of IBD. However, the molecular mechanisms involved in IBD-associated lymphangiogenesis are still unclear. In this study, we established a novel inflammatory lymphangiogenesis model in zebrafish larvae involving colitogenic challenge stimulated by exposure to 2,4,6-trinitrobenzenesulfonic acid (TNBS or dextran sodium sulphate (DSS. Treatment with either TNBS or DSS resulted in vascular endothelial growth factor receptor (Vegfr-dependent lymphangiogenesis in the zebrafish intestine. Reduction of intestinal inflammation by the administration of the IBD therapeutic, 5-aminosalicylic acid, reduced intestinal lymphatic expansion. Zebrafish macrophages express vascular growth factors vegfaa, vegfc and vegfd and chemical ablation of these cells inhibits intestinal lymphatic expansion, suggesting that the recruitment of macrophages to the intestine upon colitogenic challenge is required for intestinal inflammatory lymphangiogenesis. Importantly, this study highlights the potential of zebrafish as an inflammatory lymphangiogenesis model that can be used to investigate the role and mechanism of lymphangiogenesis in inflammatory diseases such as IBD.

  16. Axonal regeneration in zebrafish spinal cord

    Science.gov (United States)

    Hui, Subhra Prakash

    2018-01-01

    Abstract In the present review we discuss two interrelated events—axonal damage and repair—known to occur after spinal cord injury (SCI) in the zebrafish. Adult zebrafish are capable of regenerating axonal tracts and can restore full functionality after SCI. Unlike fish, axon regeneration in the adult mammalian central nervous system is extremely limited. As a consequence of an injury there is very little repair of disengaged axons and therefore functional deficit persists after SCI in adult mammals. In contrast, peripheral nervous system axons readily regenerate following injury and hence allow functional recovery both in mammals and fish. A better mechanistic understanding of these three scenarios could provide a more comprehensive insight into the success or failure of axonal regeneration after SCI. This review summarizes the present understanding of the cellular and molecular basis of axonal regeneration, in both the peripheral nervous system and the central nervous system, and large scale gene expression analysis is used to focus on different events during regeneration. The discovery and identification of genes involved in zebrafish spinal cord regeneration and subsequent functional experimentation will provide more insight into the endogenous mechanism of myelination and remyelination. Furthermore, precise knowledge of the mechanism underlying the extraordinary axonal regeneration process in zebrafish will also allow us to unravel the potential therapeutic strategies to be implemented for enhancing regrowth and remyelination of axons in mammals. PMID:29721326

  17. Effects of alpha particles on zebrafish embryos

    International Nuclear Information System (INIS)

    Yum, E.H.W.; Choi, V.W.Y.; Yu, K.N.; Li, V.W.T.; Cheng, S.H.

    2008-01-01

    Full text: Ionizing radiation such as X-ray and alpha particles can damage cellular macromolecules, which can lead to DNA single- and double-strand breaks. In the present work, we studied the effects of alpha particles on dechorionated zebrafish embryos. Thin polyallyldiglycol carbonate (PADC) films with a thickness of 16 μm were prepared from commercially available PADC films (with thickness of 100 μm) by chemical etching and used as support substrates for holding zebrafish embryos for alpha-particle irradiation. These films recorded alpha-particle hit positions, quantified the number and energy of alpha particles actually incident on the embryo cells, and thus enabled the calculation of the dose absorbed by the embryo cells. Irradiation was made at 1.25 hours post fertilization (hpf) with various absorbed dose. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was performed on the embryos at different time stages after irradiation. Marked apoptosis was detected only in embryos at earlier time stages. The results showed that DNA double-strand break during zebrafish embryogenesis can be induced by alpha-particle irradiation, which suggests that zebrafish is a potential model for assessing the effects of alpha-particle radiation

  18. Silver nanoparticles enhance wound healing in zebrafish (Danio rerio).

    Science.gov (United States)

    Seo, Seung Beom; Dananjaya, S H S; Nikapitiya, Chamilani; Park, Bae Keun; Gooneratne, Ravi; Kim, Tae-Yoon; Lee, Jehee; Kim, Cheol-Hee; De Zoysa, Mahanama

    2017-09-01

    Silver nanoparticles (AgNPs) were successfully synthesized by a chemical reduction method, physico-chemically characterized and their effect on wound-healing activity in zebrafish was investigated. The prepared AgNPs were circular-shaped, water soluble with average diameter and zeta potential of 72.66 nm and -0.45 mv, respectively. Following the creation of a laser skin wound on zebrafish, the effect of AgNPs on wound-healing activity was tested by two methods, direct skin application (2 μg/wound) and immersion in a solution of AgNPs and water (50 μg/L). The zebrafish were followed for 20 days post-wounding (dpw) by visual observation of wound size, calculating wound healing percentage (WHP), and histological examination. Visually, both direct skin application and immersion AgNPs treatments displayed clear and faster wound closure at 5, 10 and 20 dpw compared to the controls, which was confirmed by 5 dpw histology data. At 5 dpw, WHP was highest in the AgNPs immersion group (36.6%) > AgNPs direct application group (23.7%) > controls (18.2%), showing that WHP was most effective in fish immersed in AgNPs solution. In general, exposure to AgNPs induced gene expression of selected wound-healing-related genes, namely, transforming growth factor (TGF-β), matrix metalloproteinase (MMP) -9 and -13, pro-inflammatory cytokines (IL-1β and TNF-α) and antioxidant enzymes (superoxide dismutase and catalase), which observed differentiation at 12 and 24 h against the control; but the results were not consistently significant, and many either reached basal levels or were down regulated at 5 dpw in the wounded muscle. These results suggest that AgNPs are effective in acceleration of wound healing and altered the expression of some wound-healing-related genes. However, the detailed mechanism of enhanced wound healing remains to be investigated in fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Nitric oxide permits hypoxia-induced lymphatic perfusion by controlling arterial-lymphatic conduits in zebrafish and glass catfish

    DEFF Research Database (Denmark)

    Dahl Ejby Jensen, Lasse; Cao, Renhai; Hedlund, Eva-Maria

    2009-01-01

    and lymphatic perfusion. Here we show in the adult zebrafish and glass catfish (Kryptopterus bicirrhis) that blood-lymphatic conduits directly connect arterial vessels to the lymphatic system. Under hypoxic conditions, arterial-lymphatic conduits (ALCs) became highly dilated and linearized by NO...

  20. Defects of the Glycinergic Synapse in Zebrafish

    Science.gov (United States)

    Ogino, Kazutoyo; Hirata, Hiromi

    2016-01-01

    Glycine mediates fast inhibitory synaptic transmission. Physiological importance of the glycinergic synapse is well established in the brainstem and the spinal cord. In humans, the loss of glycinergic function in the spinal cord and brainstem leads to hyperekplexia, which is characterized by an excess startle reflex to sudden acoustic or tactile stimulation. In addition, glycinergic synapses in this region are also involved in the regulation of respiration and locomotion, and in the nociceptive processing. The importance of the glycinergic synapse is conserved across vertebrate species. A teleost fish, the zebrafish, offers several advantages as a vertebrate model for research of glycinergic synapse. Mutagenesis screens in zebrafish have isolated two motor defective mutants that have pathogenic mutations in glycinergic synaptic transmission: bandoneon (beo) and shocked (sho). Beo mutants have a loss-of-function mutation of glycine receptor (GlyR) β-subunit b, alternatively, sho mutant is a glycinergic transporter 1 (GlyT1) defective mutant. These mutants are useful animal models for understanding of glycinergic synaptic transmission and for identification of novel therapeutic agents for human diseases arising from defect in glycinergic transmission, such as hyperekplexia or glycine encephalopathy. Recent advances in techniques for genome editing and for imaging and manipulating of a molecule or a physiological process make zebrafish more attractive model. In this review, we describe the glycinergic defective zebrafish mutants and the technical advances in both forward and reverse genetic approaches as well as in vivo visualization and manipulation approaches for the study of the glycinergic synapse in zebrafish. PMID:27445686

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

    Science.gov (United States)

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

    2017-06-01

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

  2. Detection of vitellogenin incorporation into zebrafish oocytes by FITC fluorescence

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    Yokoi Hayato

    2011-04-01

    Full Text Available Abstract Background Large volumes of lymph can be collected from the eye-sacs of bubble-eye goldfish. We attempted to induce vitellogenin (Vtg in the eye-sac lymph of bubble-eye goldfish and develop a method for visualizing Vtg incorporation by zebrafish oocytes using FITC-labeling. Methods Estrogen efficiently induced Vtg in the eye-sac lymph of goldfish. After FITC-labeled Vtg was prepared, it was injected into mature female zebrafish. Results Incorporation of FITC-labeled Vtg by zebrafish oocytes was detected in in vivo and in vitro experiments. The embryos obtained from zebrafish females injected with FITC-labeled Vtg emitted FITC fluorescence from the yolk sac and developed normally. Conclusion This method for achieving Vtg incorporation by zebrafish oocytes could be useful in experiments related to the development and endocrinology of zebrafish oocytes.

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

    Science.gov (United States)

    Raghunath, Azhwar; Perumal, Ekambaram

    2018-01-01

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

  4. Biosecurity and Health Monitoring at the Zebrafish International Resource Center.

    Science.gov (United States)

    Murray, Katrina N; Varga, Zoltán M; Kent, Michael L

    2016-07-01

    The Zebrafish International Resource Center (ZIRC) is a repository and distribution center for mutant, transgenic, and wild-type zebrafish. In recent years annual imports of new zebrafish lines to ZIRC have increased tremendously. In addition, after 15 years of research, we have identified some of the most virulent pathogens affecting zebrafish that should be avoided in large production facilities, such as ZIRC. Therefore, while importing a high volume of new lines we prioritize safeguarding the health of our in-house fish colony. Here, we describe the biosecurity and health-monitoring program implemented at ZIRC. This strategy was designed to prevent introduction of new zebrafish pathogens, minimize pathogens already present in the facility, and ensure a healthy zebrafish colony for in-house uses and shipment to customers.

  5. Laser capture microdissection of gonads from juvenile zebrafish

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Nielsen, John; Morthorst, Jane Ebsen

    2009-01-01

    was adjusted and optimised to isolate juvenile zebrafish gonads. Results: The juvenile zebrafish gonad is not morphologically distinguishable when using dehydrated cryosections on membrane slides and a specific staining method is necessary to identify the gonads. The protocol setup in this study allows......Background: Investigating gonadal gene expression is important in attempting to elucidate the molecular mechanism of sex determination and differentiation in the model species zebrafish. However, the small size of juvenile zebrafish and correspondingly their gonads complicates this type...... of investigation. Furthermore, the lack of a genetic sex marker in juvenile zebrafish prevents pooling gonads from several individuals. The aim of this study was to establish a method to isolate the gonads from individual juvenile zebrafish allowing future investigations of gonadal gene expression during sex...

  6. Dithiocarbamates are teratogenic to developing zebrafish through inhibition of lysyl oxidase activity

    International Nuclear Information System (INIS)

    Boxtel, Antonius L. van; Kamstra, Jorke H.; Fluitsma, Donna M.; Legler, Juliette

    2010-01-01

    Dithiocarbamates (DTCs) are a class of compounds that are extensively used in agriculture as pesticides. As such, humans and wildlife are undoubtedly exposed to these chemicals. Although DTCs are thought to be relatively safe due to their short half lives, it is well established that they are teratogenic to vertebrates, especially to fish. In zebrafish, these teratogenic effects are characterized by distorted notochord development and shortened anterior to posterior axis. DTCs are known copper (Cu) chelators but this does not fully explain the observed teratogenic effects. We show here that DTCs cause malformations in zebrafish that highly resemble teratogenic effects observed by direct inhibition of a group of cuproenzymes termed lysyl oxidases (LOX). Additionally, we demonstrate that partial knockdown of three LOX genes, lox, loxl1 and loxl5b, sensitizes the developing embryo to DTC exposure. Finally, we show that DTCs directly inhibit zebrafish LOX activity in an ex vivo amine oxidase assay. Taken together, these results provide the first evidence that DTC induced teratogenic effects are, at least in part, caused by direct inhibition of LOX activity.

  7. Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

    Science.gov (United States)

    Baars, Destiny L.; Pelegri, Francisco

    2016-01-01

    Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole duplication, this method results in a precise cell division stall during the second cell cycle. The precise one-cycle division stall, coupled to unaffected DNA duplication, results in whole genome duplication. Protocols associated with this method include egg and sperm collection, UV treatment of sperm, in vitro fertilization and heat pulse to cause a one-cell cycle division delay and ploidy duplication. A modified version of this protocol could be applied to induce ploidy changes in other animal species. PMID:28060351

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

    Directory of Open Access Journals (Sweden)

    Claudia Hohn

    2013-11-01

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

  9. The primary role of zebrafish nanog is in extra-embryonic tissue.

    Science.gov (United States)

    Gagnon, James A; Obbad, Kamal; Schier, Alexander F

    2018-01-09

    The role of the zebrafish transcription factor Nanog has been controversial. It has been suggested that Nanog is primarily required for the proper formation of the extra-embryonic yolk syncytial layer (YSL) and only indirectly regulates gene expression in embryonic cells. In an alternative scenario, Nanog has been proposed to directly regulate transcription in embryonic cells during zygotic genome activation. To clarify the roles of Nanog, we performed a detailed analysis of zebrafish nanog mutants. Whereas zygotic nanog mutants survive to adulthood, maternal-zygotic (MZ nanog ) and maternal mutants exhibit developmental arrest at the blastula stage. In the absence of Nanog, YSL formation and epiboly are abnormal, embryonic tissue detaches from the yolk, and the expression of dozens of YSL and embryonic genes is reduced. Epiboly defects can be rescued by generating chimeric embryos of MZ nanog embryonic tissue with wild-type vegetal tissue that includes the YSL and yolk cell. Notably, cells lacking Nanog readily respond to Nodal signals and when transplanted into wild-type hosts proliferate and contribute to embryonic tissues and adult organs from all germ layers. These results indicate that zebrafish Nanog is necessary for proper YSL development but is not directly required for embryonic cell differentiation. © 2018. Published by The Company of Biologists Ltd.

  10. Dissection of vertebrate hematopoiesis using zebrafish thrombopoietin

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Ondřej; Stachura, D.L.; Machoňová, Olga; Pajer, Petr; Brynda, Jiří; Zon, L.I.; Traver, D.; Bartůněk, Petr

    2014-01-01

    Roč. 124, č. 2 (2014), s. 220-228 ISSN 0006-4971 R&D Projects: GA ČR GAP305/10/0953 Grant - others:NIH(US) K01-DK087814-01A1; NIH(US) R01-DK074482 Keywords : Zebrafish * hematopoiesis * progenitors * thrombopoietin * erythropoietin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.452, year: 2014

  11. Ethanol Exposure Causes Muscle Degeneration in Zebrafish

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    Elizabeth C. Coffey

    2018-03-01

    Full Text Available Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA, which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle.

  12. Mercury-induced epigenetic transgenerational inheritance of abnormal neurobehavior is correlated with sperm epimutations in zebrafish.

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    Michael J Carvan

    Full Text Available Methylmercury (MeHg is a ubiquitous environmental neurotoxicant, with human exposures predominantly resulting from fish consumption. Developmental exposure of zebrafish to MeHg is known to alter their neurobehavior. The current study investigated the direct exposure and transgenerational effects of MeHg, at tissue doses similar to those detected in exposed human populations, on sperm epimutations (i.e., differential DNA methylation regions [DMRs] and neurobehavior (i.e., visual startle and spontaneous locomotion in zebrafish, an established human health model. F0 generation embryos were exposed to MeHg (0, 1, 3, 10, 30, and 100 nM for 24 hours ex vivo. F0 generation control and MeHg-exposed lineages were reared to adults and bred to yield the F1 generation, which was subsequently bred to the F2 generation. Direct exposure (F0 generation and transgenerational actions (F2 generation were then evaluated. Hyperactivity and visual deficit were observed in the unexposed descendants (F2 generation of the MeHg-exposed lineage compared to control. An increase in F2 generation sperm epimutations was observed relative to the F0 generation. Investigation of the DMRs in the F2 generation MeHg-exposed lineage sperm revealed associated genes in the neuroactive ligand-receptor interaction and actin-cytoskeleton pathways being effected, which correlate to the observed neurobehavioral phenotypes. Developmental MeHg-induced epigenetic transgenerational inheritance of abnormal neurobehavior is correlated with sperm epimutations in F2 generation adult zebrafish. Therefore, mercury can promote the epigenetic transgenerational inheritance of disease in zebrafish, which significantly impacts its environmental health considerations in all species including humans.

  13. Human amyloidogenic light chain proteins result in cardiac dysfunction, cell death, and early mortality in zebrafish.

    Science.gov (United States)

    Mishra, Shikha; Guan, Jian; Plovie, Eva; Seldin, David C; Connors, Lawreen H; Merlini, Giampaolo; Falk, Rodney H; MacRae, Calum A; Liao, Ronglih

    2013-07-01

    Systemic amyloid light-chain (AL) amyloidosis is associated with rapidly progressive and fatal cardiomyopathy resulting from the direct cardiotoxic effects of circulating AL light chain (AL-LC) proteins and the indirect effects of AL fibril tissue infiltration. Cardiac amyloidosis is resistant to standard heart failure therapies, and, to date, there are limited treatment options for these patients. The mechanisms underlying the development of cardiac amyloidosis and AL-LC cardiotoxicity are largely unknown, and their study has been limited by the lack of a suitable in vivo model system. Here, we establish an in vivo zebrafish model of human AL-LC-induced cardiotoxicity. AL-LC isolated from AL cardiomyopathy patients or control nonamyloidogenic LC protein isolated from multiple myeloma patients (Con-LC) was directly injected into the circulation of zebrafish at 48 h postfertilization. AL-LC injection resulted in impaired cardiac function, pericardial edema, and increased cell death relative to Con-LC, culminating in compromised survival with 100% mortality within 2 wk, independent of AL fibril deposition. Prior work has implicated noncanonical p38 MAPK activation in the pathogenesis of AL-LC-induced cardiotoxicity, and p38 MAPK inhibition via SB-203580 rescued AL-LC-induced cardiac dysfunction and cell death and attenuated mortality in zebrafish. This in vivo zebrafish model of AL-LC cardiotoxicity demonstrates that antagonism of p38 MAPK within the AL-LC cardiotoxic signaling response may serve to improve cardiac function and mortality in AL cardiomyopathy. Furthermore, this in vivo model system will allow for further study of the molecular underpinnings of AL cardiotoxicity and identification of novel therapeutic strategies.

  14. Disease modeling in genetic kidney diseases: zebrafish.

    Science.gov (United States)

    Schenk, Heiko; Müller-Deile, Janina; Kinast, Mark; Schiffer, Mario

    2017-07-01

    Growing numbers of translational genomics studies are based on the highly efficient and versatile zebrafish (Danio rerio) vertebrate model. The increasing types of zebrafish models have improved our understanding of inherited kidney diseases, since they not only display pathophysiological changes but also give us the opportunity to develop and test novel treatment options in a high-throughput manner. New paradigms in inherited kidney diseases have been developed on the basis of the distinct genome conservation of approximately 70 % between zebrafish and humans in terms of existing gene orthologs. Several options are available to determine the functional role of a specific gene or gene sets. Permanent genome editing can be induced via complete gene knockout by using the CRISPR/Cas-system, among others, or via transient modification by using various morpholino techniques. Cross-species rescues succeeding knockdown techniques are employed to determine the functional significance of a target gene or a specific mutation. This article summarizes the current techniques and discusses their perspectives.

  15. Afferent connectivity of the zebrafish habenulae

    Directory of Open Access Journals (Sweden)

    Katherine Jane Turner

    2016-04-01

    Full Text Available The habenulae are bilateral nuclei located in the dorsal diencephalon that are conserved across vertebrates.Here we describe the main afferents to the habenulae in larval and adult zebrafish.We observe afferents from the subpallium, nucleus rostrolateralis,posterior tuberculum, posterior hypothalamic lobe, median raphe, olfactory bulb to the right habenula and from the parapineal to the lefthabenula.In addition,we find afferents from a ventrolateral telencephalic nucleus that neurochemical and hodological data identify as the ventral entopeduncular nucleus(vENT,confirming and extending observations of Amo et al.(2014.Fate map and marker studies suggest that vENT originates from the diencephalic prethalamic eminence and extends into the lateral telencephalon from 48 to 120 hpf.No afferents to the habenula were observed from the dorsal entopeduncular nucleus(dENT.Consequently,we confirm that the vENT(and not the dENT should be considered as the entopeduncular nucleus proper in zebrafish.Furthermore,comparison with data in other vertebrates suggests that the vENT is a conserved basal ganglia nucleus,being homologous to the entopeduncular nucleus of mammals(internal segment of the globus pallidus of primates by both embryonic origin and projections,as previously suggested by Amo et al.(2014.Key words: habenula,connections,afferents,entopeduncular nucleus,posterior tuberculum,basal ganglia,zebrafish

  16. CERKL knockdown causes retinal degeneration in zebrafish.

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    Marina Riera

    Full Text Available The human CERKL gene is responsible for common and severe forms of retinal dystrophies. Despite intense in vitro studies at the molecular and cellular level and in vivo analyses of the retina of murine knockout models, CERKL function remains unknown. In this study, we aimed to approach the developmental and functional features of cerkl in Danio rerio within an Evo-Devo framework. We show that gene expression increases from early developmental stages until the formation of the retina in the optic cup. Unlike the high mRNA-CERKL isoform multiplicity shown in mammals, the moderate transcriptional complexity in fish facilitates phenotypic studies derived from gene silencing. Moreover, of relevance to pathogenicity, teleost CERKL shares the two main human protein isoforms. Morpholino injection has been used to generate a cerkl knockdown zebrafish model. The morphant phenotype results in abnormal eye development with lamination defects, failure to develop photoreceptor outer segments, increased apoptosis of retinal cells and small eyes. Our data support that zebrafish Cerkl does not interfere with proliferation and neural differentiation during early developmental stages but is relevant for survival and protection of the retinal tissue. Overall, we propose that this zebrafish model is a powerful tool to unveil CERKL contribution to human retinal degeneration.

  17. Use of zebrafish to study Shigella infection

    Science.gov (United States)

    Duggan, Gina M.

    2018-01-01

    ABSTRACT Shigella is a leading cause of dysentery worldwide, responsible for up to 165 million cases of shigellosis each year. Shigella is also recognised as an exceptional model pathogen to study key issues in cell biology and innate immunity. Several infection models have been useful to explore Shigella biology; however, we still lack information regarding the events taking place during the Shigella infection process in vivo. Here, we discuss a selection of mechanistic insights recently gained from studying Shigella infection of zebrafish (Danio rerio), with a focus on cytoskeleton rearrangements and cellular immunity. We also discuss how infection of zebrafish can be used to investigate new concepts underlying infection control, including emergency granulopoiesis and the use of predatory bacteria to combat antimicrobial resistance. Collectively, these insights illustrate how Shigella infection of zebrafish can provide fundamental advances in our understanding of bacterial pathogenesis and vertebrate host defence. This information should also provide vital clues for the discovery of new therapeutic strategies against infectious disease in humans. PMID:29590642

  18. Use of zebrafish to study Shigella infection

    Directory of Open Access Journals (Sweden)

    Gina M. Duggan

    2018-02-01

    Full Text Available Shigella is a leading cause of dysentery worldwide, responsible for up to 165 million cases of shigellosis each year. Shigella is also recognised as an exceptional model pathogen to study key issues in cell biology and innate immunity. Several infection models have been useful to explore Shigella biology; however, we still lack information regarding the events taking place during the Shigella infection process in vivo. Here, we discuss a selection of mechanistic insights recently gained from studying Shigella infection of zebrafish (Danio rerio, with a focus on cytoskeleton rearrangements and cellular immunity. We also discuss how infection of zebrafish can be used to investigate new concepts underlying infection control, including emergency granulopoiesis and the use of predatory bacteria to combat antimicrobial resistance. Collectively, these insights illustrate how Shigella infection of zebrafish can provide fundamental advances in our understanding of bacterial pathogenesis and vertebrate host defence. This information should also provide vital clues for the discovery of new therapeutic strategies against infectious disease in humans.

  19. Cell migration during heart regeneration in zebrafish.

    Science.gov (United States)

    Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

    2016-07-01

    Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Characterization of behavioral and endocrine effects of LSD on zebrafish.

    Science.gov (United States)

    Grossman, Leah; Utterback, Eli; Stewart, Adam; Gaikwad, Siddharth; Chung, Kyung Min; Suciu, Christopher; Wong, Keith; Elegante, Marco; Elkhayat, Salem; Tan, Julia; Gilder, Thomas; Wu, Nadine; Dileo, John; Cachat, Jonathan; Kalueff, Allan V

    2010-12-25

    Lysergic acid diethylamide (LSD) is a potent hallucinogenic drug that strongly affects animal and human behavior. Although adult zebrafish (Danio rerio) are emerging as a promising neurobehavioral model, the effects of LSD on zebrafish have not been investigated previously. Several behavioral paradigms (the novel tank, observation cylinder, light-dark box, open field, T-maze, social preference and shoaling tests), as well as modern video-tracking tools and whole-body cortisol assay were used to characterize the effects of acute LSD in zebrafish. While lower doses (5-100 microg/L) did not affect zebrafish behavior, 250 microg/L LSD increased top dwelling and reduced freezing in the novel tank and observation cylinder tests, also affecting spatiotemporal patterns of activity (as assessed by 3D reconstruction of zebrafish traces and ethograms). LSD evoked mild thigmotaxis in the open field test, increased light behavior in the light-dark test, reduced the number of arm entries and freezing in the T-maze and social preference test, without affecting social preference. In contrast, LSD affected zebrafish shoaling (increasing the inter-fish distance in a group), and elevated whole-body cortisol levels. Overall, our findings show sensitivity of zebrafish to LSD action, and support the use of zebrafish models to study hallucinogenic drugs of abuse. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  1. FishNet: an online database of zebrafish anatomy

    Directory of Open Access Journals (Sweden)

    Gibson Abigail J

    2007-08-01

    Full Text Available Abstract Background Over the last two decades, zebrafish have been established as a genetically versatile model system for investigating many different aspects of vertebrate developmental biology. With the credentials of zebrafish as a developmental model now well recognized, the emerging new opportunity is the wider application of zebrafish biology to aspects of human disease modelling. This rapidly increasing use of zebrafish as a model for human disease has necessarily generated interest in the anatomy of later developmental phases such as the larval, juvenile, and adult stages, during which many of the key aspects of organ morphogenesis and maturation take place. Anatomical resources and references that encompass these stages are non-existent in zebrafish and there is therefore an urgent need to understand how different organ systems and anatomical structures develop throughout the life of the fish. Results To overcome this deficit we have utilized the technique of optical projection tomography to produce three-dimensional (3D models of larval fish. In order to view and display these models we have created FishNet http://www.fishnet.org.au, an interactive reference of zebrafish anatomy spanning the range of zebrafish development from 24 h until adulthood. Conclusion FishNet contains more than 36 000 images of larval zebrafish, with more than 1 500 of these being annotated. The 3D models can be manipulated on screen or virtually sectioned. This resource represents the first complete embryo to adult atlas for any species in 3D.

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

    Science.gov (United States)

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

    2008-01-01

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

  3. Examination of a Palatogenic Gene Program in Zebrafish

    Science.gov (United States)

    Swartz, Mary E.; Sheehan-Rooney, Kelly; Dixon, Michael J.; Eberhart, Johann K.

    2011-01-01

    Human palatal clefting is debilitating and difficult to rectify surgically. Animal models enhance our understanding of palatogenesis and are essential in strategies designed to ameliorate palatal malformations in humans. Recent studies have shown that the zebrafish palate, or anterior neurocranium, is under similar genetic control to the amniote palatal skeleton. We extensively analyzed palatogenesis in zebrafish to determine the similarity of gene expression and function across vertebrates. By 36 hpf palatogenic cranial neural crest cells reside in homologous regions of the developing face compared to amniote species. Transcription factors and signaling molecules regulating mouse palatogenesis are expressed in similar domains during palatogenesis in zebrafish. Functional investigation of a subset of these genes, fgf10a, tgfb2, pax9 and smad5 revealed their necessity in zebrafish palatogenesis. Collectively, these results suggest that the gene regulatory networks regulating palatogenesis may be conserved across vertebrate species, demonstrating the utility of zebrafish as a model for palatogenesis. PMID:22016187

  4. Macrophage–Microbe Interactions: Lessons from the Zebrafish Model

    Directory of Open Access Journals (Sweden)

    Nagisa Yoshida

    2017-12-01

    Full Text Available Macrophages provide front line defense against infections. The study of macrophage–microbe interplay is thus crucial for understanding pathogenesis and infection control. Zebrafish (Danio rerio larvae provide a unique platform to study macrophage–microbe interactions in vivo, from the level of the single cell to the whole organism. Studies using zebrafish allow non-invasive, real-time visualization of macrophage recruitment and phagocytosis. Furthermore, the chemical and genetic tractability of zebrafish has been central to decipher the complex role of macrophages during infection. Here, we discuss the latest developments using zebrafish models of bacterial and fungal infection. We also review novel aspects of macrophage biology revealed by zebrafish, which can potentiate development of new therapeutic strategies for humans.

  5. A dominant negative zebrafish Ahr2 partially protects developing zebrafish from dioxin toxicity.

    Directory of Open Access Journals (Sweden)

    Kevin A Lanham

    Full Text Available The toxicity by 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD is thought to be caused by activation of the aryl hydrocarbon receptor (AHR. However, our understanding of how AHR activation by TCDD leads to toxic effects is poor. Ideally we would like to manipulate AHR activity in specific tissues and at specific times. One route to this is expressing dominant negative AHRs (dnAHRs. This work describes the construction and characterization of dominant negative forms of the zebrafish Ahr2 in which the C-terminal transactivation domain was either removed, or replaced with the inhibitory domain from the Drosophila engrailed repressor protein. One of these dnAhr2s was selected for expression from the ubiquitously active e2fα promoter in transgenic zebrafish. We found that these transgenic zebrafish expressing dnAhr2 had reduced TCDD induction of the Ahr2 target gene cyp1a, as measured by 7-ethoxyresorufin-O-deethylase activity. Furthermore, the cardiotoxicity produced by TCDD, pericardial edema, heart malformation, and reduced blood flow, were all mitigated in the zebrafish expressing the dnAhr2. These results provide in vivo proof-of-principle results demonstrating the effectiveness of dnAHRs in manipulating AHR activity in vivo, and demonstrating that this approach can be a means for blocking TCDD toxicity.

  6. A Versatile Mounting Method for Long Term Imaging of Zebrafish Development.

    Science.gov (United States)

    Hirsinger, Estelle; Steventon, Ben

    2017-01-26

    Zebrafish embryos offer an ideal experimental system to study complex morphogenetic processes due to their ease of accessibility and optical transparency. In particular, posterior body elongation is an essential process in embryonic development by which multiple tissue deformations act together to direct the formation of a large part of the body axis. In order to observe this process by long-term time-lapse imaging it is necessary to utilize a mounting technique that allows sufficient support to maintain samples in the correct orientation during transfer to the microscope and acquisition. In addition, the mounting must also provide sufficient freedom of movement for the outgrowth of the posterior body region without affecting its normal development. Finally, there must be a certain degree in versatility of the mounting method to allow imaging on diverse imaging set-ups. Here, we present a mounting technique for imaging the development of posterior body elongation in the zebrafish D. rerio. This technique involves mounting embryos such that the head and yolk sac regions are almost entirely included in agarose, while leaving out the posterior body region to elongate and develop normally. We will show how this can be adapted for upright, inverted and vertical light-sheet microscopy set-ups. While this protocol focuses on mounting embryos for imaging for the posterior body, it could easily be adapted for the live imaging of multiple aspects of zebrafish development.

  7. Uncoupling nicotine mediated motoneuron axonal pathfinding errors and muscle degeneration in zebrafish

    International Nuclear Information System (INIS)

    Welsh, Lillian; Tanguay, Robert L.; Svoboda, Kurt R.

    2009-01-01

    Zebrafish embryos offer a unique opportunity to investigate the mechanisms by which nicotine exposure impacts early vertebrate development. Embryos exposed to nicotine become functionally paralyzed by 42 hpf suggesting that the neuromuscular system is compromised in exposed embryos. We previously demonstrated that secondary spinal motoneurons in nicotine-exposed embryos were delayed in development and that their axons made pathfinding errors (Svoboda, K.R., Vijayaraghaven, S., Tanguay, R.L., 2002. Nicotinic receptors mediate changes in spinal motoneuron development and axonal pathfinding in embryonic zebrafish exposed to nicotine. J. Neurosci. 22, 10731-10741). In that study, we did not consider the potential role that altered skeletal muscle development caused by nicotine exposure could play in contributing to the errors in spinal motoneuron axon pathfinding. In this study, we show that an alteration in skeletal muscle development occurs in tandem with alterations in spinal motoneuron development upon exposure to nicotine. The alteration in the muscle involves the binding of nicotine to the muscle-specific AChRs. The nicotine-induced alteration in muscle development does not occur in the zebrafish mutant (sofa potato, [sop]), which lacks muscle-specific AChRs. Even though muscle development is unaffected by nicotine exposure in sop mutants, motoneuron axonal pathfinding errors still occur in these mutants, indicating a direct effect of nicotine exposure on nervous system development.

  8. Model-free information-theoretic approach to infer leadership in pairs of zebrafish.

    Science.gov (United States)

    Butail, Sachit; Mwaffo, Violet; Porfiri, Maurizio

    2016-04-01

    Collective behavior affords several advantages to fish in avoiding predators, foraging, mating, and swimming. Although fish schools have been traditionally considered egalitarian superorganisms, a number of empirical observations suggest the emergence of leadership in gregarious groups. Detecting and classifying leader-follower relationships is central to elucidate the behavioral and physiological causes of leadership and understand its consequences. Here, we demonstrate an information-theoretic approach to infer leadership from positional data of fish swimming. In this framework, we measure social interactions between fish pairs through the mathematical construct of transfer entropy, which quantifies the predictive power of a time series to anticipate another, possibly coupled, time series. We focus on the zebrafish model organism, which is rapidly emerging as a species of choice in preclinical research for its genetic similarity to humans and reduced neurobiological complexity with respect to mammals. To overcome experimental confounds and generate test data sets on which we can thoroughly assess our approach, we adapt and calibrate a data-driven stochastic model of zebrafish motion for the simulation of a coupled dynamical system of zebrafish pairs. In this synthetic data set, the extent and direction of the coupling between the fish are systematically varied across a wide parameter range to demonstrate the accuracy and reliability of transfer entropy in inferring leadership. Our approach is expected to aid in the analysis of collective behavior, providing a data-driven perspective to understand social interactions.

  9. Zebrafish embryos as a screen for DNA methylation modifications after compound exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bouwmeester, Manon C.; Ruiter, Sander; Lommelaars, Tobias; Sippel, Josefine; Hodemaekers, Hennie M. [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Brandhof, Evert-Jan van den [Center for Environmental Quality, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Pennings, Jeroen L.A. [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands); Kamstra, Jorke H. [Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Jelinek, Jaroslav [Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA (United States); Issa, Jean-Pierre J. [Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA (United States); Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Legler, Juliette [Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Ven, Leo T.M. van der, E-mail: leo.van.der.ven@rivm.nl [Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven (Netherlands)

    2016-01-15

    Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. - Highlights: • Compound induced effects on DNA methylation in zebrafish embryos • Global methylation not an informative biomarker • Minimal genome

  10. Zebrafish embryos as a screen for DNA methylation modifications after compound exposure

    International Nuclear Information System (INIS)

    Bouwmeester, Manon C.; Ruiter, Sander; Lommelaars, Tobias; Sippel, Josefine; Hodemaekers, Hennie M.; Brandhof, Evert-Jan van den; Pennings, Jeroen L.A.; Kamstra, Jorke H.; Jelinek, Jaroslav; Issa, Jean-Pierre J.; Legler, Juliette; Ven, Leo T.M. van der

    2016-01-01

    Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis. - Highlights: • Compound induced effects on DNA methylation in zebrafish embryos • Global methylation not an informative biomarker • Minimal genome

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

    Science.gov (United States)

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

    2013-02-01

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

  12. Zebrafish: an animal model for research in veterinary medicine.

    Science.gov (United States)

    Nowik, N; Podlasz, P; Jakimiuk, A; Kasica, N; Sienkiewicz, W; Kaleczyc, J

    2015-01-01

    The zebrafish (Danio rerio) has become known as an excellent model organism for studies of vertebrate biology, vertebrate genetics, embryonal development, diseases and drug screening. Nevertheless, there is still lack of detailed reports about usage of the zebrafish as a model in veterinary medicine. Comparing to other vertebrates, they can lay hundreds of eggs at weekly intervals, externally fertilized zebrafish embryos are accessible to observation and manipulation at all stages of their development, which makes possible to simplify the research techniques such as fate mapping, fluorescent tracer time-lapse lineage analysis and single cell transplantation. Although zebrafish are only 2.5 cm long, they are easy to maintain. Intraperitoneal and intracerebroventricular injections, blood sampling and measurement of food intake are possible to be carry out in adult zebrafish. Danio rerio is a useful animal model for neurobiology, developmental biology, drug research, virology, microbiology and genetics. A lot of diseases, for which the zebrafish is a perfect model organism, affect aquatic animals. For a part of them, like those caused by Mycobacterium marinum or Pseudoloma neutrophila, Danio rerio is a natural host, but the zebrafish is also susceptible to the most of fish diseases including Itch, Spring viraemia of carp and Infectious spleen and kidney necrosis. The zebrafish is commonly used in research of bacterial virulence. The zebrafish embryo allows for rapid, non-invasive and real time analysis of bacterial infections in a vertebrate host. Plenty of common pathogens can be examined using zebrafish model: Streptococcus iniae, Vibrio anguillarum or Listeria monocytogenes. The steps are taken to use the zebrafish also in fungal research, especially that dealing with Candida albicans and Cryptococcus neoformans. Although, the zebrafish is used commonly as an animal model to study diseases caused by external agents, it is also useful in studies of metabolic

  13. Adaptive locomotor behavior in larval zebrafish.

    Science.gov (United States)

    Portugues, Ruben; Engert, Florian

    2011-01-01

    In this study we report that larval zebrafish display adaptive locomotor output that can be driven by unexpected visual feedback. We develop a new assay that addresses visuomotor integration in restrained larval zebrafish. The assay involves a closed-loop environment in which the visual feedback a larva receives depends on its own motor output in a way that resembles freely swimming conditions. The experimenter can control the gain of this closed feedback loop, so that following a given motor output the larva experiences more or less visual feedback depending on whether the gain is high or low. We show that increases and decreases in this gain setting result in adaptive changes in behavior that lead to a generalized decrease or increase of motor output, respectively. Our behavioral analysis shows that both the duration and tail beat frequency of individual swim bouts can be modified, as well as the frequency with which bouts are elicited. These changes can be implemented rapidly, following an exposure to a new gain of just 175 ms. In addition, modifications in some behavioral parameters accumulate over tens of seconds and effects last for at least 30 s from trial to trial. These results suggest that larvae establish an internal representation of the visual feedback expected from a given motor output and that the behavioral modifications are driven by an error signal that arises from the discrepancy between this expectation and the actual visual feedback. The assay we develop presents a unique possibility for studying visuomotor integration using imaging techniques available in the larval zebrafish.

  14. GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio ...

    Science.gov (United States)

    Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the current study we examined whether the larvae can be reared on a processed diet alone, live food alone, or the combination while maintaining normal locomotor behavior, and acceptable survival, length and weight at 14 dpf in a static system. A 14 day feeding trial was conducted in glass crystallizing dishes containing 500 ml of 4 ppt Instant Ocean. On day 0 pdf 450 embryos were selected as potential study subjects and placed in a 26○C incubator on a 14:10 (light:dark) light cycle. At 4 dpf 120 normally developing embryos were selected per treatment and divided into 3 bowls of 40 embryos (for an n=3 per treatment; 9 bowls total). Treatment groups were: G (Gemma Micro 75 only), R (L-type marine rotifers (Brachionus plicatilis) only) or B (Gemma and rotifers). Growth (length), survival, water quality and rotifer density were monitored on days 5-14. On day 14, weight of larva in each bowl was measured and 8 larva per bowl were selected for use in locomotor testing. This behavior paradigm tests individual larval zebrafish under both light and dark conditions in a 24-well plate.After 14 dpf, survival among the groups was not different (92-98%). By days 7 -14 R and B larvae were ~2X longer

  15. Premature aging in telomerase-deficient zebrafish

    Directory of Open Access Journals (Sweden)

    Monique Anchelin

    2013-09-01

    The study of telomere biology is crucial to the understanding of aging and cancer. In the pursuit of greater knowledge in the field of human telomere biology, the mouse has been used extensively as a model. However, there are fundamental differences between mouse and human cells. Therefore, additional models are required. In light of this, we have characterized telomerase-deficient zebrafish (Danio rerio as the second vertebrate model for human telomerase-driven diseases. We found that telomerase-deficient zebrafish show p53-dependent premature aging and reduced lifespan in the first generation, as occurs in humans but not in mice, probably reflecting the similar telomere length in fish and humans. Among these aging symptoms, spinal curvature, liver and retina degeneration, and infertility were the most remarkable. Although the second-generation embryos died in early developmental stages, restoration of telomerase activity rescued telomere length and survival, indicating that telomerase dosage is crucial. Importantly, this model also reproduces the disease anticipation observed in humans with dyskeratosis congenita (DC. Thus, telomerase haploinsufficiency leads to anticipation phenomenon in longevity, which is related to telomere shortening and, specifically, with the proportion of short telomeres. Furthermore, p53 was induced by telomere attrition, leading to growth arrest and apoptosis. Importantly, genetic inhibition of p53 rescued the adverse effects of telomere loss, indicating that the molecular mechanisms induced by telomere shortening are conserved from fish to mammals. The partial rescue of telomere length and longevity by restoration of telomerase activity, together with the feasibility of the zebrafish for high-throughput chemical screening, both point to the usefulness of this model for the discovery of new drugs able to reactivate telomerase in individuals with DC.

  16. Novel biomarkers of perchlorate exposure in zebrafish

    Science.gov (United States)

    Mukhi, S.; Carr, J.A.; Anderson, T.A.; Patino, R.

    2005-01-01

    Perchlorate inhibits iodide uptake by thyroid follicles and lowers thyroid hormone production. Although several effects of perchlorate on the thyroid system have been reported, the utility of these pathologies as markers of environmental perchlorate exposures has not been adequately assessed. The present study examined time-course and concentration-dependent effects of perchlorate on thyroid follicle hypertrophy, colloid depletion, and angiogenesis; alterations in whole-body thyroxine (T4) levels; and somatic growth and condition factor of subadult and adult zebrafish. Changes in the intensity of the colloidal T4 ring previously observed in zebrafish also were examined immunohistochemically. Three-month-old zebrafish were exposed to ammonium perchlorate at measured perchlorate concentrations of 0, 11, 90, 1,131, and 11,480 ppb for 12 weeks and allowed to recover in clean water for 12 weeks. At two weeks of exposure, the lowest-observed-effective concentrations (LOECs) of perchlorate that induced angiogenesis and depressed the intensity of colloidal T4 ring were 90 and 1,131 ppb, respectively; other parameters were not affected (whole-body T4 was not determined at this time). At 12 weeks of exposure, LOECs for colloid depletion, hypertrophy, angiogenesis, and colloidal T4 ring were 11,480, 1,131, 90, and 11 ppb, respectively. All changes were reversible, but residual effects on angiogenesis and colloidal T4 ring intensity were still present after 12 weeks of recovery (LOEC, 11,480 ppb). Whole-body T 4 concentration, body growth (length and weight), and condition factor were not affected by perchlorate. The sensitivity and longevity of changes in colloidal T4 ring intensity and angiogenesis suggest their usefulness as novel markers of perchlorate exposure. The 12-week LOEC for colloidal T4 ring is the lowest reported for any perchlorate biomarker in aquatic vertebrates. ?? 2005 SETAC.

  17. Cholinergic innervation of the zebrafish olfactory bulb.

    Science.gov (United States)

    Edwards, Jeffrey G; Greig, Ann; Sakata, Yoko; Elkin, Dimitry; Michel, William C

    2007-10-20

    A number of fish species receive forebrain cholinergic input but two recent reports failed to find evidence of cholinergic cell bodies or fibers in the olfactory bulbs (OBs) of zebrafish. In the current study we sought to confirm these findings by examining the OBs of adult zebrafish for choline acetyltransferase (ChAT) immunoreactivity. We observed a diffuse network of varicose ChAT-positive fibers associated with the nervus terminalis ganglion innervating the mitral cell/glomerular layer (MC/GL). The highest density of these fibers occurred in the anterior region of the bulb. The cellular targets of this cholinergic input were identified by exposing isolated OBs to acetylcholine receptor (AChR) agonists in the presence of agmatine (AGB), a cationic probe that permeates some active ion channels. Nicotine (50 microM) significantly increased the activity-dependent labeling of mitral cells and juxtaglomerular cells but not of tyrosine hydroxlase-positive dopaminergic neurons (TH(+) cells) compared to control preparations. The nAChR antagonist mecamylamine, an alpha7-nAChR subunit-specific antagonist, calcium-free artificial cerebrospinal fluid, or a cocktail of ionotropic glutamate receptor (iGluR) antagonists each blocked nicotine-stimulated labeling, suggesting that AGB does not enter the labeled neurons through activated nAChRs but rather through activated iGluRs following ACh-stimulated glutamate release. Deafferentation of OBs did not eliminate nicotine-stimulated labeling, suggesting that cholinergic input is primarily acting on bulbar neurons. These findings confirm the presence of a functioning cholinergic system in the zebrafish OB.

  18. Learning and memory in zebrafish (Danio rerio).

    Science.gov (United States)

    Gerlai, R

    2016-01-01

    Learning and memory are defining features of our own species inherently important to our daily lives and to who we are. Without our memories we cease to exist as a person. Without our ability to learn individuals and collectively our society would cease to function. Diseases of the mind still remain incurable. The interest in understanding of the mechanisms of learning and memory is thus well founded. Given the complexity of such mechanisms, concerted efforts have been made to study them under controlled laboratory conditions, ie, with laboratory model organisms. The zebrafish, although new in this field, is one such model organism. The rapidly developing forward- and reverse genetic methods designed for the zebrafish and the increasing use of pharmacological tools along with numerous neurobiology techniques make this species perhaps the best model for the analysis of the mechanisms of complex central nervous system characteristics. The fact that it is an evolutionarily ancient and simpler vertebrate, but at the same time it possesses numerous conserved features across multiple levels of biological organization makes this species an excellent tool for the analysis of the mechanisms of learning and memory. The bottleneck lies in our understanding of its cognitive and mnemonic features, the topic of this chapter. The current paper builds on a chapter published in the previous edition and continues to focus on associative learning, but now it extends the discussion to other forms of learning and to recent discoveries on memory-related features and findings obtained both in adults and larval zebrafish. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Characterization of the Zebrafish Homolog of Zipper Interacting Protein Kinase

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    Brandon W. Carr

    2014-06-01

    Full Text Available Zipper-interacting protein kinase (ZIPK is a conserved vertebrate-specific regulator of actomyosin contractility in smooth muscle and non-muscle cells. Murine ZIPK has undergone an unusual divergence in sequence and regulation compared to other ZIPK orthologs. In humans, subcellular localization is controlled by phosphorylation of threonines 299 and 300. In contrast, ZIPK subcellular localization in mouse and rat is controlled by interaction with PAR-4. We carried out a comparative biochemical characterization of the regulation of the zebrafish ortholog of ZIPK. Like the human orthologs zebrafish ZIPK undergoes nucleocytoplasmic-shuttling and is abundant in the cytoplasm, unlike the primarily nuclear rat ZIPK. Rat ZIPK, but not human or zebrafish ZIPK, interacts with zebrafish PAR-4. Mutation of the conserved residues required for activation of the mammalian orthologs abrogated activity of the zebrafish ZIPK. In contrast to the human ortholog, mutation of threonine 299 and 300 in the zebrafish ZIPK has no effect on the activity or subcellular localization. Thus, we found that zebrafish ZIPK functions in a manner most similar to the human ZIPK and quite distinct from murine orthologs, yet the regulation of subcellular localization is not conserved.

  20. Zebrafish: A Versatile Animal Model for Fertility Research

    Directory of Open Access Journals (Sweden)

    Jing Ying Hoo

    2016-01-01

    Full Text Available The utilization of zebrafish in biomedical research is very common in the research world nowadays. Today, it has emerged as a favored vertebrate organism for the research in science of reproduction. There is a significant growth in amount numbers of scientific literature pertaining to research discoveries in reproductive sciences in zebrafish. It has implied the importance of zebrafish in this particular field of research. In essence, the current available literature has covered from the very specific brain region or neurons of zebrafish, which are responsible for reproductive regulation, until the gonadal level of the animal. The discoveries and findings have proven that this small animal is sharing a very close/similar reproductive system with mammals. More interestingly, the behavioral characteristics and along with the establishment of animal courtship behavior categorization in zebrafish have laid an even stronger foundation and firmer reason on the suitability of zebrafish utilization in research of reproductive sciences. In view of the immense importance of this small animal for the development of reproductive sciences, this review aimed at compiling and describing the proximate close similarity of reproductive regulation on zebrafish and human along with factors contributing to the infertility, showing its versatility and its potential usage for fertility research.

  1. Genetic determinants of hyaloid and retinal vasculature in zebrafish

    Directory of Open Access Journals (Sweden)

    Hyde David R

    2007-10-01

    Full Text Available Abstract Background The retinal vasculature is a capillary network of blood vessels that nourishes the inner retina of most mammals. Developmental abnormalities or microvascular complications in the retinal vasculature result in severe human eye diseases that lead to blindness. To exploit the advantages of zebrafish for genetic, developmental and pharmacological studies of retinal vasculature, we characterised the intraocular vasculature in zebrafish. Results We show a detailed morphological and developmental analysis of the retinal blood supply in zebrafish. Similar to the transient hyaloid vasculature in mammalian embryos, vessels are first found attached to the zebrafish lens at 2.5 days post fertilisation. These vessels progressively lose contact with the lens and by 30 days post fertilisation adhere to the inner limiting membrane of the juvenile retina. Ultrastructure analysis shows these vessels to exhibit distinctive hallmarks of mammalian retinal vasculature. For example, smooth muscle actin-expressing pericytes are ensheathed by the basal lamina of the blood vessel, and vesicle vacuolar organelles (VVO, subcellular mediators of vessel-retinal nourishment, are present. Finally, we identify 9 genes with cell membrane, extracellular matrix and unknown identity that are necessary for zebrafish hyaloid and retinal vasculature development. Conclusion Zebrafish have a retinal blood supply with a characteristic developmental and adult morphology. Abnormalities of these intraocular vessels are easily observed, enabling application of genetic and chemical approaches in zebrafish to identify molecular regulators of hyaloid and retinal vasculature in development and disease.

  2. The zebrafish world of colors and shapes: preference and discrimination.

    Science.gov (United States)

    Oliveira, Jessica; Silveira, Mayara; Chacon, Diana; Luchiari, Ana

    2015-04-01

    Natural environment imposes many challenges to animals, which have to use cognitive abilities to cope with and exploit it to enhance their fitness. Since zebrafish is a well-established model for cognitive studies and high-throughput screening for drugs and diseases that affect cognition, we tested their ability for ambient color preference and 3D objects discrimination to establish a protocol for memory evaluation. For the color preference test, zebrafish were observed in a multiple-chamber tank with different environmental color options. Zebrafish showed preference for blue and green, and avoided yellow and red. For the 3D objects discrimination, zebrafish were allowed to explore two equal objects and then observed in a one-trial test in which a new color, size, or shape of the object was presented. Zebrafish showed discrimination for color, shape, and color+shape combined, but not size. These results imply that zebrafish seem to use some categorical system to discriminate items, and distracters affect their ability for discrimination. The type of variables available (color and shape) may favor zebrafish objects perception and facilitate discrimination processing. We suggest that this easy and simple memory test could serve as a useful screening tool for cognitive dysfunction and neurotoxicological studies.

  3. Method for somatic cell nuclear transfer in zebrafish.

    Science.gov (United States)

    Siripattarapravat, Kannika; Cibelli, Jose B

    2011-01-01

    Somatic cell nuclear transfer (SCNT) has been a well-known technique for decades and widely applied to generate identical animals, including ones with genetic alterations. The system has been demonstrated successfully in zebrafish. The elaborated requirements of SCNT, however, limit reproducibility of the established model to a few groups in zebrafish research community. In this chapter, we meticulously outline each step of the published protocol as well as preparations of equipments and reagents used in zebrafish SCNT. All describable detailed-tips are elaborated in texts and figures. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Afferent Connectivity of the Zebrafish Habenulae

    Science.gov (United States)

    Turner, Katherine J.; Hawkins, Thomas A.; Yáñez, Julián; Anadón, Ramón; Wilson, Stephen W.; Folgueira, Mónica

    2016-01-01

    The habenulae are bilateral nuclei located in the dorsal diencephalon that are conserved across vertebrates. Here we describe the main afferents to the habenulae in larval and adult zebrafish. We observe afferents from the subpallium, nucleus rostrolateralis, posterior tuberculum, posterior hypothalamic lobe, median raphe; we also see asymmetric afferents from olfactory bulb to the right habenula, and from the parapineal to the left habenula. In addition, we find afferents from a ventrolateral telencephalic nucleus that neurochemical and hodological data identify as the ventral entopeduncular nucleus (vENT), confirming and extending observations of Amo et al. (2014). Fate map and marker studies suggest that vENT originates from the diencephalic prethalamic eminence and extends into the lateral telencephalon from 48 to 120 hour post-fertilization (hpf). No afferents to the habenula were observed from the dorsal entopeduncular nucleus (dENT). Consequently, we confirm that the vENT (and not the dENT) should be considered as the entopeduncular nucleus “proper” in zebrafish. Furthermore, comparison with data in other vertebrates suggests that the vENT is a conserved basal ganglia nucleus, being homologous to the entopeduncular nucleus of mammals (internal segment of the globus pallidus of primates) by both embryonic origin and projections, as previously suggested by Amo et al. (2014). PMID:27199671

  5. Effect of Mefloquine, a Gap Junction Blocker, on Circadian Period2 Gene Oscillation in the Mouse Suprachiasmatic Nucleus

    Directory of Open Access Journals (Sweden)

    Jinmi Koo

    2015-09-01

    Full Text Available BackgroundIn mammals, the master circadian pacemaker is localized in an area of the ventral hypothalamus known as the suprachiasmatic nucleus (SCN. Previous studies have shown that pacemaker neurons in the SCN are highly coupled to one another, and this coupling is crucial for intrinsic self-sustainability of the SCN central clock, which is distinguished from peripheral oscillators. One plausible mechanism underlying the intercellular communication may involve direct electrical connections mediated by gap junctions.MethodsWe examined the effect of mefloquine, a neuronal gap junction blocker, on circadian Period 2 (Per2 gene oscillation in SCN slice cultures prepared from Per2::luciferase (PER2::LUC knock-in mice using a real-time bioluminescence measurement system.ResultsAdministration of mefloquine causes instability in the pulse period and a slight reduction of amplitude in cyclic PER2::LUC expression. Blockade of gap junctions uncouples PER2::LUC-expressing cells, in terms of phase transition, which weakens synchrony among individual cellular rhythms.ConclusionThese findings suggest that neuronal gap junctions play an important role in synchronizing the central pacemaker neurons and contribute to the distinct self-sustainability of the SCN master clock.

  6. Phenotype classification of zebrafish embryos by supervised learning.

    Directory of Open Access Journals (Sweden)

    Nathalie Jeanray

    Full Text Available Zebrafish is increasingly used to assess biological properties of chemical substances and thus is becoming a specific tool for toxicological and pharmacological studies. The effects of chemical substances on embryo survival and development are generally evaluated manually through microscopic observation by an expert and documented by several typical photographs. Here, we present a methodology to automatically classify brightfield images of wildtype zebrafish embryos according to their defects by using an image analysis approach based on supervised machine learning. We show that, compared to manual classification, automatic classification results in 90 to 100% agreement with consensus voting of biological experts in nine out of eleven considered defects in 3 days old zebrafish larvae. Automation of the analysis and classification of zebrafish embryo pictures reduces the workload and time required for the biological expert and increases the reproducibility and objectivity of this classification.

  7. Functional inhibition of UQCRB suppresses angiogenesis in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yoon Sun; Jung, Hye Jin [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Seok, Seung Hyeok [Department of Microbiology and Immunology, Institute for Experimental Animals, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Payumo, Alexander Y.; Chen, James K. [Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305 (United States); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2013-04-19

    Highlights: ► This is the first functional characterization of UQCRB in vivo model. ► Angiogenesis is inhibited with UQCRB loss of function in zebrafish. ► UQCRB is introduced as a prognostic marker for mitochondria- and angiogenesis-related diseases. -- Abstract: As a subunit of mitochondrial complex III, UQCRB plays an important role in complex III stability, electron transport, and cellular oxygen sensing. Herein, we report UQCRB function regarding angiogenesis in vivo with the zebrafish (Danio rerio). UQCRB knockdown inhibited angiogenesis in zebrafish leading to the suppression of VEGF expression. Moreover, the UQCRB-targeting small molecule terpestacin also inhibited angiogenesis and VEGF levels in zebrafish, supporting the role of UQCRB in angiogenesis. Collectively, UQCRB loss of function by either genetic and pharmacological means inhibited angiogenesis, indicating that UQCRB plays a key role in this process and can be a prognostic marker of angiogenesis- and mitochondria-related diseases.

  8. Zebrafish models in neuropsychopharmacology and CNS drug discovery.

    Science.gov (United States)

    Khan, Kanza M; Collier, Adam D; Meshalkina, Darya A; Kysil, Elana V; Khatsko, Sergey L; Kolesnikova, Tatyana; Morzherin, Yury Yu; Warnick, Jason E; Kalueff, Allan V; Echevarria, David J

    2017-07-01

    Despite the high prevalence of neuropsychiatric disorders, their aetiology and molecular mechanisms remain poorly understood. The zebrafish (Danio rerio) is increasingly utilized as a powerful animal model in neuropharmacology research and in vivo drug screening. Collectively, this makes zebrafish a useful tool for drug discovery and the identification of disordered molecular pathways. Here, we discuss zebrafish models of selected human neuropsychiatric disorders and drug-induced phenotypes. As well as covering a broad range of brain disorders (from anxiety and psychoses to neurodegeneration), we also summarize recent developments in zebrafish genetics and small molecule screening, which markedly enhance the disease modelling and the discovery of novel drug targets. © 2017 The British Pharmacological Society.

  9. Functional inhibition of UQCRB suppresses angiogenesis in zebrafish

    International Nuclear Information System (INIS)

    Cho, Yoon Sun; Jung, Hye Jin; Seok, Seung Hyeok; Payumo, Alexander Y.; Chen, James K.; Kwon, Ho Jeong

    2013-01-01

    Highlights: ► This is the first functional characterization of UQCRB in vivo model. ► Angiogenesis is inhibited with UQCRB loss of function in zebrafish. ► UQCRB is introduced as a prognostic marker for mitochondria- and angiogenesis-related diseases. -- Abstract: As a subunit of mitochondrial complex III, UQCRB plays an important role in complex III stability, electron transport, and cellular oxygen sensing. Herein, we report UQCRB function regarding angiogenesis in vivo with the zebrafish (Danio rerio). UQCRB knockdown inhibited angiogenesis in zebrafish leading to the suppression of VEGF expression. Moreover, the UQCRB-targeting small molecule terpestacin also inhibited angiogenesis and VEGF levels in zebrafish, supporting the role of UQCRB in angiogenesis. Collectively, UQCRB loss of function by either genetic and pharmacological means inhibited angiogenesis, indicating that UQCRB plays a key role in this process and can be a prognostic marker of angiogenesis- and mitochondria-related diseases

  10. Social learning of an associative foraging task in zebrafish

    Science.gov (United States)

    Zala, Sarah M.; Määttänen, Ilmari

    2013-05-01

    The zebrafish ( Danio rerio) is increasingly becoming an important model species for studies on the genetic and neural mechanisms controlling behaviour and cognition. Here, we utilized a conditioned place preference (CPP) paradigm to study social learning in zebrafish. We tested whether social interactions with conditioned demonstrators enhance the ability of focal naïve individuals to learn an associative foraging task. We found that the presence of conditioned demonstrators improved focal fish foraging behaviour through the process of social transmission, whereas the presence of inexperienced demonstrators interfered with the learning of the control focal fish. Our results indicate that zebrafish use social learning for finding food and that this CPP paradigm is an efficient assay to study social learning and memory in zebrafish.

  11. Multiple zebrafish atoh1 genes specify a diversity of neuronal types in the zebrafish cerebellum.

    Science.gov (United States)

    Kidwell, Chelsea U; Su, Chen-Ying; Hibi, Masahiko; Moens, Cecilia B

    2018-06-01

    A single Atoh1 basic-helix-loop-helix transcription factor specifies multiple neuron types in the mammalian cerebellum and anterior hindbrain. The zebrafish genome encodes three paralagous atoh1 genes whose functions in cerebellum and anterior hindbrain development we explore here. With use of a transgenic reporter, we report that zebrafish atoh1c-expressing cells are organized in two distinct domains that are separated both by space and developmental time. An early isthmic expression domain gives rise to an extracerebellar population in rhombomere 1 and an upper rhombic lip domain gives rise to granule cell progenitors that migrate to populate all four granule cell territories of the fish cerebellum. Using genetic mutants we find that of the three zebrafish atoh1 paralogs, atoh1c and atoh1a are required for the full complement of granule neurons. Surprisingly, the two genes are expressed in non-overlapping granule cell progenitor populations, indicating that fish use duplicate atoh1 genes to generate granule cell diversity that is not detected in mammals. Finally, live imaging of granule cell migration in wildtype and atoh1c mutant embryos reveals that while atoh1c is not required for granule cell specification per se, it is required for granule cells to delaminate and migrate away from the rhombic lip. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Two-Photon-Based Photoactivation in Live Zebrafish Embryos

    OpenAIRE

    Russek-Blum, Niva; Nabel-Rosen, Helit; Levkowitz, Gil

    2010-01-01

    Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic development, cellular signaling and adult physiology. In this respect, the use of multi-photon microscopy enables quantitative photoactivation of a given light responsive agent in deep tissues at a single cell resolution. As zebrafish embryos are optically transparent, their development can be monitored in vivo. These traits make the zebrafish a...

  13. Study on radiation modifiers with zebrafish as a vertebrate model

    International Nuclear Information System (INIS)

    Lei Jixiao; Ni Jin; Cai Jianming; Shen Jianliang

    2010-01-01

    Zebrafish (Danio rerio) as a vertebrate model system has been used in a series of biomedical experiments by scientists. It offers distinctive benefits as a laboratory model system, especially for embryonic development, gene expression, drug screening and human disease model. In this paper, the typical radiation modifiers, such as Amifostine, DF-1, AG1478, Flavopiridol and DNA repair proteins involved in biomedical process by use of zebrafish have been reviewed. (authors)

  14. Microcystin-LR exposure induces developmental neurotoxicity in zebrafish embryo

    International Nuclear Information System (INIS)

    Wu, Qin; Yan, Wei; Liu, Chunsheng; Li, Li; Yu, Liqin; Zhao, Sujuan; Li, Guangyu

    2016-01-01

    Microcystin-LR (MCLR) is a commonly acting potent hepatotoxin and has been pointed out of potentially causing developmental neurotoxicity, but the exact mechanism is little known. In this study, zebrafish embryos were exposed to 0, 0.8, 1.6 or 3.2 mg/L MCLR for 120 h. MCLR exposure through submersion caused serious hatching delay and body length decrease. The content of MCLR in zebrafish larvae was analyzed and the results demonstrated that MCLR can accumulate in zebrafish larvae. The locomotor speed of zebrafish larvae was decreased. Furthermore, the dopamine and acetylcholine (ACh) content were detected to be significantly decreased in MCLR exposure groups. And the acetylcholinesterase (AChE) activity was significantly increased after exposure to 1.6 and 3.2 mg/L MCLR. The transcription pattern of manf, chrnα7 and ache gene was consistent with the change of the dopamine content, ACh content and AChE activity. Gene expression involved in the development of neurons was also measured. α1-tubulin and shha gene expression were down-regulated, whereas mbp and gap43 gene expression were observed to be significantly up-regulated upon exposure to MCLR. The above results indicated that MCLR-induced developmental toxicity might attribute to the disorder of cholinergic system, dopaminergic signaling, and the development of neurons. - Highlights: • MCLR accumulation induces developmental neurotoxicity in zebrafish embryo. • The decrease of dopamine levels might be associated with the MCLR-induced developmental neurotoxicity in zebrafish larvae. • The alternation of cholinergic system might contribute to the change of neurobehavior in zebrafish larvae exposure with MCLR. - MCLR accumulation induces developmental neurotoxicity by affecting cholinergic system, dopaminergic signaling, and the development of neurons in zebrafish embryo.

  15. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    OpenAIRE

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2010-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

  16. The dynamics of neutrophils in zebrafish (Danio rerio) during infection with the parasite Ichthyophthirius multifiliis

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff

    2016-01-01

    Ichthyophthirius multifiliis is a ciliated protozoan parasite infecting the skin and gills of freshwater fish. Neutrophils are attracted to the infection sites, as a part of the innate immune response. In this study a transgenic line of zebrafish (Tg(MPO:GFP)i114) with GFP-tagged neutrophils was ...... the infection. Neutrophils interacted directly with the parasites with pseudopod formation projecting towards the pathogen. These results indicate a strong innate immune response immediately following infection and/or a subsequent immune evasion by the parasite....

  17. Bio-electrosprayed multicellular zebrafish embryos are viable and develop normally

    International Nuclear Information System (INIS)

    Clarke, Jonathan D W; Jayasinghe, Suwan N

    2008-01-01

    Bio-electrosprays are rapidly emerging as a viable protocol for directly engineering living cells. This communication reports the bio-electrospraying of multicellular organisms, namely zebrafish embryos. The results demonstrate that the bio-electrospray protocol fails to induce any embryological perturbations. In addition to analysing overall embryo morphology, we use transgenic embryos that express green fluorescent protein in specific brain neurons to determine that neuronal numbers and organization are completely normal. These results demonstrate that the bio-electrospraying protocol does not interfere with the complex gene regulation and cell movements required for the development of a multicellular organism. (communication)

  18. Whole-body and multispectral photoacoustic imaging of adult zebrafish

    Science.gov (United States)

    Huang, Na; Xi, Lei

    2016-10-01

    Zebrafish is a top vertebrate model to study developmental biology and genetics, and it is becoming increasingly popular for studying human diseases due to its high genome similarity to that of humans and the optical transparency in embryonic stages. However, it becomes difficult for pure optical imaging techniques to volumetric visualize the internal organs and structures of wild-type zebrafish in juvenile and adult stages with excellent resolution and penetration depth. Even with the establishment of mutant lines which remain transparent over the life cycle, it is still a challenge for pure optical imaging modalities to image the whole body of adult zebrafish with micro-scale resolution. However, the method called photoacoustic imaging that combines all the advantages of the optical imaging and ultrasonic imaging provides a new way to image the whole body of the zebrafish. In this work, we developed a non-invasive photoacoustic imaging system with optimized near-infrared illumination and cylindrical scanning to image the zebrafish. The lateral and axial resolution yield to 80 μm and 600 μm, respectively. Multispectral strategy with wavelengths from 690 nm to 930 nm was employed to image various organs inside the zebrafish. From the reconstructed images, most major organs and structures inside the body can be precisely imaged. Quantitative and statistical analysis of absorption for organs under illumination with different wavelengths were carried out.

  19. Zebrafish Lacking Circadian Gene per2 Exhibit Visual Function Deficiency

    Directory of Open Access Journals (Sweden)

    Deng-feng Huang

    2018-03-01

    Full Text Available The retina has an intrinsic circadian clock, but the importance of this clock for vision is unknown. Zebrafish offer many advantages for studying vertebrate vision and circadian rhythm. Here, we explored the role of zebrafish per2, a light-regulated gene, in visual behavior and the underlying mechanisms. We observed that per2 mutant zebrafish larvae showed decreased contrast sensitivity and visual acuity using optokinetic response (OKR assays. Using a visual motor response (VMR assay, we observed normal OFF responses but abnormal ON responses in mutant zebrafish larvae. Immunofluorescence showed that mutants had a normal morphology of cone photoreceptor cells and retinal organization. However, electron microscopy showed that per2 mutants displayed abnormal and decreased photoreceptor ribbon synapses with arciform density, which resulted in retinal ON pathway defect. We also examined the expression of three cone opsins by quantitative real-time PCR (qRT-PCR, and the expression of long-wave-sensitive opsin (opn1lw and short-wave-sensitive opsin (opn1sw was reduced in mutant zebrafish larvae. qRT-PCR analyses also showed a down-regulation of the clock genes cry1ba and bmal1b in the adult eye of per2 mutant zebrafish. This study identified a mechanism by which a clock gene affects visual function and defined important roles of per2 in retinal information processing.

  20. ESX-5-deficient Mycobacterium marinum is hypervirulent in adult zebrafish

    KAUST Repository

    Weerdenburg, Eveline M.

    2012-02-15

    ESX-5 is a mycobacterial type VII protein secretion system responsible for transport of numerous PE and PPE proteins. It is involved in the induction of host cell death and modulation of the cytokine response in vitro. In this work, we studied the effects of ESX-5 in embryonic and adult zebrafish using Mycobacterium marinum. We found that ESX-5-deficient M.marinum was slightly attenuated in zebrafish embryos. Surprisingly, the same mutant showed highly increased virulence in adult zebrafish, characterized by increased bacterial loads and early onset of granuloma formation with rapid development of necrotic centres. This early onset of granuloma formation was accompanied by an increased expression of pro-inflammatory cytokines and tissue remodelling genes in zebrafish infected with the ESX-5 mutant. Experiments using RAG-1-deficient zebrafish showed that the increased virulence of the ESX-5 mutant was not dependent on the adaptive immune system. Mixed infection experiments with wild-type and ESX-5 mutant bacteria showed that the latter had a specific advantage in adult zebrafish and outcompeted wild-type bacteria. Together our experiments indicate that ESX-5-mediated protein secretion is used by M.marinum to establish a moderate and persistent infection. © 2012 Blackwell Publishing Ltd.

  1. Heart-specific expression of laminopathic mutations in transgenic zebrafish.

    Science.gov (United States)

    Verma, Ajay D; Parnaik, Veena K

    2017-07-01

    Lamins are key determinants of nuclear organization and function in the metazoan nucleus. Mutations in human lamin A cause a spectrum of genetic diseases that affect cardiac muscle and skeletal muscle as well as other tissues. A few laminopathies have been modeled using the mouse. As zebrafish is a well established model for the study of cardiac development and disease, we have investigated the effects of heart-specific lamin A mutations in transgenic zebrafish. We have developed transgenic lines of zebrafish expressing conserved lamin A mutations that cause cardiac dysfunction in humans. Expression of zlamin A mutations Q291P and M368K in the heart was driven by the zebrafish cardiac troponin T2 promoter. Homozygous mutant embryos displayed nuclear abnormalities in cardiomyocyte nuclei. Expression analysis showed the upregulation of genes involved in heart regeneration in transgenic mutant embryos and a cell proliferation marker was increased in adult heart tissue. At the physiological level, there was deviation of up to 20% from normal heart rate in transgenic embryos expressing mutant lamins. Adult homozygous zebrafish were fertile and did not show signs of early mortality. Our results suggest that transgenic zebrafish models of heart-specific laminopathies show cardiac regeneration and moderate deviations in heart rate during embryonic development. © 2017 International Federation for Cell Biology.

  2. Zebrafish Models of Human Leukemia: Technological Advances and Mechanistic Insights.

    Science.gov (United States)

    Harrison, Nicholas R; Laroche, Fabrice J F; Gutierrez, Alejandro; Feng, Hui

    2016-01-01

    Insights concerning leukemic pathophysiology have been acquired in various animal models and further efforts to understand the mechanisms underlying leukemic treatment resistance and disease relapse promise to improve therapeutic strategies. The zebrafish (Danio rerio) is a vertebrate organism with a conserved hematopoietic program and unique experimental strengths suiting it for the investigation of human leukemia. Recent technological advances in zebrafish research including efficient transgenesis, precise genome editing, and straightforward transplantation techniques have led to the generation of a number of leukemia models. The transparency of the zebrafish when coupled with improved lineage-tracing and imaging techniques has revealed exquisite details of leukemic initiation, progression, and regression. With these advantages, the zebrafish represents a unique experimental system for leukemic research and additionally, advances in zebrafish-based high-throughput drug screening promise to hasten the discovery of novel leukemia therapeutics. To date, investigators have accumulated knowledge of the genetic underpinnings critical to leukemic transformation and treatment resistance and without doubt, zebrafish are rapidly expanding our understanding of disease mechanisms and helping to shape therapeutic strategies for improved outcomes in leukemic patients.

  3. Normal anatomy and histology of the adult zebrafish.

    Science.gov (United States)

    Menke, Aswin L; Spitsbergen, Jan M; Wolterbeek, Andre P M; Woutersen, Ruud A

    2011-08-01

    The zebrafish has been shown to be an excellent vertebrate model for studying the roles of specific genes and signaling pathways. The sequencing of its genome and the relative ease with which gene modifications can be performed have led to the creation of numerous human disease models that can be used for testing the potential and the toxicity of new pharmaceutical compounds. Many pharmaceutical companies already use the zebrafish for prescreening purposes. So far, the focus has been on ecotoxicity and the effects on embryonic development, but there is a trend to expand the use of the zebrafish with acute, subchronic, and chronic toxicity studies that are currently still carried out with the more conventional test animals such as rodents. However, before we can fully realize the potential of the zebrafish as an animal model for understanding human development, disease, and toxicology, we must first greatly advance our knowledge of normal zebrafish physiology, anatomy, and histology. To further this knowledge, we describe, in the present article, location and histology of the major zebrafish organ systems with a brief description of their function.

  4. Abnormal Nuclear Pore Formation Triggers Apoptosis in the Intestinal Epithelium of elys-Deficient Zebrafish

    NARCIS (Netherlands)

    de Jong-Curtain, Tanya A.; Parslow, Adam C.; Trotter, Andrew J.; Hall, Nathan E.; Verkade, Heather; Tabone, Tania; Christie, Elizabeth L.; Crowhurst, Meredith O.; Layton, Judith E.; Shepherd, Iain T.; Nixon, Susan J.; Parton, Robert G.; Zon, Leonard I.; Stainier, Didier Y. R.; Lieschke, Graham J.; Heath, Joan K.

    Background & Aims: Zebrafish mutants generated by ethylnitrosourea-mutagenesis provide a powerful toot for dissecting the genetic regulation of developmental processes, including organogenesis. One zebrafish mutant, "flotte lotte" (flo), displays striking defects in intestinal, liver, pancreas, and

  5. Quo natas, Danio?—Recent Progress in Modeling Cancer in Zebrafish

    Directory of Open Access Journals (Sweden)

    Stefanie Kirchberger

    2017-08-01

    Full Text Available Over the last decade, zebrafish has proven to be a powerful model in cancer research. Zebrafish form tumors that histologically and genetically resemble human cancers. The live imaging and cost-effective compound screening possible with zebrafish especially complement classic mouse cancer models. Here, we report recent progress in the field, including genetically engineered zebrafish cancer models, xenotransplantation of human cancer cells into zebrafish, promising approaches toward live investigation of the tumor microenvironment, and identification of therapeutic strategies by performing compound screens on zebrafish cancer models. Given the recent advances in genome editing, personalized zebrafish cancer models are now a realistic possibility. In addition, ongoing automation will soon allow high-throughput compound screening using zebrafish cancer models to be part of preclinical precision medicine approaches.

  6. Transient infection of the zebrafish notochord with E. coli induces chronic inflammation

    Directory of Open Access Journals (Sweden)

    Mai Nguyen-Chi

    2014-07-01

    Full Text Available Zebrafish embryos and larvae are now well-established models in which to study infectious diseases. Infections with non-pathogenic Gram-negative Escherichia coli induce a strong and reproducible inflammatory response. Here, we study the cellular response of zebrafish larvae when E. coli bacteria are injected into the notochord and describe the effects. First, we provide direct evidence that the notochord is a unique organ that is inaccessible to leukocytes (macrophages and neutrophils during the early stages of inflammation. Second, we show that notochord infection induces a host response that is characterised by rapid clearance of the bacteria, strong leukocyte recruitment around the notochord and prolonged inflammation that lasts several days after bacteria clearance. During this inflammatory response, il1b is first expressed in macrophages and subsequently at high levels in neutrophils. Moreover, knock down of il1b alters the recruitment of neutrophils to the notochord, demonstrating the important role of this cytokine in the maintenance of inflammation in the notochord. Eventually, infection of the notochord induces severe defects of the notochord that correlate with neutrophil degranulation occurring around this tissue. This is the first in vivo evidence that neutrophils can degranulate in the absence of a direct encounter with a pathogen. Persistent inflammation, neutrophil infiltration and restructuring of the extracellular matrix are defects that resemble those seen in bone infection and in some chondropathies. As the notochord is a transient embryonic structure that is closely related to cartilage and bone and that contributes to vertebral column formation, we propose infection of the notochord in zebrafish larvae as a new model to study the cellular and molecular mechanisms underlying cartilage and bone inflammation.

  7. Transient infection of the zebrafish notochord with E. coli induces chronic inflammation.

    Science.gov (United States)

    Nguyen-Chi, Mai; Phan, Quang Tien; Gonzalez, Catherine; Dubremetz, Jean-François; Levraud, Jean-Pierre; Lutfalla, Georges

    2014-07-01

    Zebrafish embryos and larvae are now well-established models in which to study infectious diseases. Infections with non-pathogenic Gram-negative Escherichia coli induce a strong and reproducible inflammatory response. Here, we study the cellular response of zebrafish larvae when E. coli bacteria are injected into the notochord and describe the effects. First, we provide direct evidence that the notochord is a unique organ that is inaccessible to leukocytes (macrophages and neutrophils) during the early stages of inflammation. Second, we show that notochord infection induces a host response that is characterised by rapid clearance of the bacteria, strong leukocyte recruitment around the notochord and prolonged inflammation that lasts several days after bacteria clearance. During this inflammatory response, il1b is first expressed in macrophages and subsequently at high levels in neutrophils. Moreover, knock down of il1b alters the recruitment of neutrophils to the notochord, demonstrating the important role of this cytokine in the maintenance of inflammation in the notochord. Eventually, infection of the notochord induces severe defects of the notochord that correlate with neutrophil degranulation occurring around this tissue. This is the first in vivo evidence that neutrophils can degranulate in the absence of a direct encounter with a pathogen. Persistent inflammation, neutrophil infiltration and restructuring of the extracellular matrix are defects that resemble those seen in bone infection and in some chondropathies. As the notochord is a transient embryonic structure that is closely related to cartilage and bone and that contributes to vertebral column formation, we propose infection of the notochord in zebrafish larvae as a new model to study the cellular and molecular mechanisms underlying cartilage and bone inflammation. © 2014. Published by The Company of Biologists Ltd.

  8. Monitoring of single-cell responses in the optic tectum of adult zebrafish with dextran-coupled calcium dyes delivered via local electroporation.

    Directory of Open Access Journals (Sweden)

    Vanessa Kassing

    Full Text Available The zebrafish (Danio rerio has become one of the major animal models for in vivo examination of sensory and neuronal computation. Similar to Xenopus tadpoles neural activity in the optic tectum, the major region controlling visually guided behavior, can be examined in zebrafish larvae by optical imaging. Prerequisites of these approaches are usually the transparency of larvae up to a certain age and the use of two-photon microscopy. This principle of fluorescence excitation was necessary to suppress crosstalk between signals from individual neurons, which is a critical issue when using membrane-permeant dyes. This makes the equipment to study neuronal processing costly and limits the approach to the study of larvae. Thus there is lack of knowledge about the properties of neurons in the optic tectum of adult animals. We established a procedure to circumvent these problems, enabling in vivo calcium imaging in the optic tectum of adult zebrafish. Following local application of dextran-coupled dyes single-neuron activity of adult zebrafish can be monitored with conventional widefield microscopy, because dye labeling remains restricted to tens of neurons or less. Among the neurons characterized with our technique we found neurons that were selective for a certain pattern orientation as well as neurons that responded in a direction-selective way to visual motion. These findings are consistent with previous studies and indicate that the functional integrity of neuronal circuits in the optic tectum of adult zebrafish is preserved with our staining technique. Overall, our protocol for in vivo calcium imaging provides a useful approach to monitor visual responses of individual neurons in the optic tectum of adult zebrafish even when only widefield microscopy is available. This approach will help to obtain valuable insight into the principles of visual computation in adult vertebrates and thus complement previous work on developing visual circuits.

  9. Developmental toxicity of cartap on zebrafish embryos.

    Science.gov (United States)

    Zhou, Shengli; Dong, Qiaoxiang; Li, Shaonan; Guo, Jiangfeng; Wang, Xingxing; Zhu, Guonian

    2009-12-13

    Cartap is a widely used insecticide which belongs to a member of nereistoxin derivatives and acts on nicotinic acetylcholine receptor site. Its effects on aquatic species are of grave concern. To explore the potential developmental toxicity of cartap, zebrafish embryos were continually exposed, from 0.5 to 144h post-fertilization, to a range of concentrations of 25-1000microg/l. Results of the experiment indicated that cartap concentrations of 100microg/l and above negatively affected embryo survival and hatching success. Morphological analysis uncovered a large suite of abnormalities such as less melanin pigmentation, wavy notochord, crooked trunk, fuzzy somites, neurogenesis defects and vasculature defects. The most sensitive organ was proved to be the notochord which displayed defects at concentrations as low as 25microg/l. Both sensitivity towards exposure and localization of the defect were stage specific. To elucidate mechanisms concerning notochord, pigmentation, and hatching defects, enzyme assay, RT Q-PCR, and different exposure strategies were performed. For embryos with hatching failure, chorion was verified not to be digested, while removing cartap from exposure at early pre-hatching stage could significantly increase the hatching success. However, cartap was proved, via vitro assay, to have no effect on proteolytic activity of hatching enzyme. These findings implied that the secretion of hatching enzyme might be blocked. We also revealed that cartap inhibited the activity of melanogenic enzyme tyrosinase and matrix enzyme lysyl oxidase and induced expression of their genes. These suggested that cartap could impaired melanin pigmentation of zebrafish embryos through inhibiting tyrosinase activity, while inhibition of lysyl oxidase activity was responsible for notochord undulation, which subsequently caused somite defect, and at least partially responsible for defects in vasculature and neurogenesis.

  10. An algorithm to track laboratory zebrafish shoals.

    Science.gov (United States)

    Feijó, Gregory de Oliveira; Sangalli, Vicenzo Abichequer; da Silva, Isaac Newton Lima; Pinho, Márcio Sarroglia

    2018-05-01

    In this paper, a semi-automatic multi-object tracking method to track a group of unmarked zebrafish is proposed. This method can handle partial occlusion cases, maintaining the correct identity of each individual. For every object, we extracted a set of geometric features to be used in the two main stages of the algorithm. The first stage selected the best candidate, based both on the blobs identified in the image and the estimate generated by a Kalman Filter instance. In the second stage, if the same candidate-blob is selected by two or more instances, a blob-partitioning algorithm takes place in order to split this blob and reestablish the instances' identities. If the algorithm cannot determine the identity of a blob, a manual intervention is required. This procedure was compared against a manual labeled ground truth on four video sequences with different numbers of fish and spatial resolution. The performance of the proposed method is then compared against two well-known zebrafish tracking methods found in the literature: one that treats occlusion scenarios and one that only track fish that are not in occlusion. Based on the data set used, the proposed method outperforms the first method in correctly separating fish in occlusion, increasing its efficiency by at least 8.15% of the cases. As for the second, the proposed method's overall performance outperformed the second in some of the tested videos, especially those with lower image quality, because the second method requires high-spatial resolution images, which is not a requirement for the proposed method. Yet, the proposed method was able to separate fish involved in occlusion and correctly assign its identity in up to 87.85% of the cases, without accounting for user intervention. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Kaempferol Identified by Zebrafish Assay and Fine Fractionations Strategy from Dysosma versipellis Inhibits Angiogenesis through VEGF and FGF Pathways

    Science.gov (United States)

    Liang, Fang; Han, Yuxiang; Gao, Hao; Xin, Shengchang; Chen, Shaodan; Wang, Nan; Qin, Wei; Zhong, Hanbing; Lin, Shuo; Yao, Xinsheng; Li, Song

    2015-01-01

    Natural products are a rich resource for the discovery of therapeutic substances. By directly using 504 fine fractions from isolated traditional Chinese medicine plants, we performed a transgenic zebrafish based screen for anti-angiogenesis substances. One fraction, DYVE-D3, was found to inhibit the growth of intersegmental vessels in the zebrafish vasculature. Bioassay-guided isolation of DYVE-D3 indicates that the flavonoid kaempferol was the active substance. Kaempferol also inhibited the proliferation and migration of HUVECs in vitro. Furthermore, we found that kaempferol suppressed angiogenesis through inhibiting VEGFR2 expression, which can be enhanced by FGF inhibition. In summary, this study shows that the construction of fine fraction libraries allows efficient identification of active substances from natural products. PMID:26446489

  12. Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

    Science.gov (United States)

    Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

    2017-02-01

    This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

  13. Potential teratogenicity of methimazole: exposure of zebrafish embryos to methimazole causes similar developmental anomalies to human methimazole embryopathy.

    Science.gov (United States)

    Komoike, Yuta; Matsuoka, Masato; Kosaki, Kenjiro

    2013-06-01

    While methimazole (MMI) is widely used in the therapy for hyperthyroidism, several groups have reported that maternal exposure to MMI results in a variety of congenital anomalies, including choanal and esophageal atresia, iridic and retinal coloboma, and delayed neurodevelopment. Thus, adverse effects of maternal exposure to MMI on fetal development have long been suggested; however, direct evidence for the teratogenicity of MMI has not been presented. Therefore, we studied the effects of MMI on early development by using zebrafish as a model organism. The fertilized eggs of zebrafish were collected immediately after spawning and grown in egg culture water containing MMI at various concentrations. External observation of the embryos revealed that exposure to high concentrations of MMI resulted in loss of pigmentation, hypoplastic hindbrain, turbid tissue in the forebrain, swelling of the notochord, and curly trunk. Furthermore, these effects occurred in a dose-dependent manner. Precise observation of the serial cross-sections of MMI-exposed embryos elucidated delayed development and hypoplasia of the whole brain and spinal cord, narrowing of the pharynx and esophagus, severe disruption of the retina, and aberrant structure of the notochord. These neuronal, pharyngeal, esophageal, and retinal anomalous morphologies have a direct analogy to the congenital anomalies observed in children exposed to MMI in utero. Here, we show the teratogenic effects of MMI on the development of zebrafish and provide the first experimental evidence for the connection between exposure to MMI and human MMI embryopathy. © 2013 Wiley Periodicals, Inc.

  14. Cyp1a reporter zebrafish reveals target tissues for dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun-Hee [Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju (Korea, Republic of); Department of Microbiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Park, Hye-Jeong [Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju (Korea, Republic of); Kim, Jin Hee [Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju (Korea, Republic of); Department of Microbiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Kim, Suhyun [Graduate School of Medicine, Korea University, Ansan (Korea, Republic of); Williams, Darren R. [New Drug Targets Laboratory, School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Kim, Myeong-Kyu [Department of Neurology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Jung, Young Do [Department of Biochemistry, Chonnam National University Medical School, Gwangju (Korea, Republic of); Teraoka, Hiroki [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu (Japan); Park, Hae-Chul [Graduate School of Medicine, Korea University, Ansan (Korea, Republic of); Choy, Hyon E., E-mail: hyonchoy@chonnam.ac.kr [Department of Microbiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Shin, Boo Ahn, E-mail: bashin@chonnam.ac.kr [Department of Microbiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Choi, Seok-Yong, E-mail: zebrafish@chonnam.ac.kr [Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju (Korea, Republic of); School of Biological Sciences and Technology, Chonnam National University, Gwangju (Korea, Republic of)

    2013-06-15

    Highlights: •2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most toxic anthropogenic substance ever identified. •Transgenic cyp1a reporter zebrafish reveals target tissues for TCDD. •The retinal bipolar cells, otic vesicle, lateral line, pancreas, cloaca and pectoral fin bud are novel targets in zebrafish for TCDD. •Our findings will further understanding of human health risks by TCDD. -- Abstract: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the unintentional byproduct of various industrial processes, is classified as human carcinogen and could disrupt reproductive, developmental and endocrine systems. Induction of cyp1a1 is used as an indicator of TCDD exposure. We sought to determine tissues that are vulnerable to TCDD toxicity using a transgenic zebrafish (Danio rerio) model. We inserted a nuclear enhanced green fluorescent protein gene (EGFP) into the start codon of a zebrafish cyp1a gene in a fosmid clone using DNA recombineering. The resulting recombineered fosmid was then used to generate cyp1a reporter zebrafish, embryos of which were exposed to TCDD. Expression pattern of EGFP in the reporter zebrafish mirrored that of endogenous cyp1a mRNA. In addition, exposure of the embryos to TCDD at as low as 10 pM for 72 h, which does not elicit morphological abnormalities of embryos, markedly increased GFP expression. Furthermore, the reporter embryos responded to other AhR ligands as well. Exposure of the embryos to TCDD revealed previously reported (the cardiovascular system, liver, pancreas, kidney, swim bladder and skin) and unreported target tissues (retinal bipolar cells, otic vesicle, lateral line, cloaca and pectoral fin bud) for TCDD. Transgenic cyp1a reporter zebrafish we have developed can further understanding of ecotoxicological relevance and human health risks by TCDD. In addition, they could be used to identify agonists of AhR and antidotes to TCDD toxicity.

  15. Evaluation of color preference in zebrafish for learning and memory.

    Science.gov (United States)

    Avdesh, Avdesh; Martin-Iverson, Mathew T; Mondal, Alinda; Chen, Mengqi; Askraba, Sreten; Morgan, Newman; Lardelli, Michael; Groth, David M; Verdile, Giuseppe; Martins, Ralph N

    2012-01-01

    There is growing interest in using zebrafish (Danio rerio) as a model of neurodegenerative disorders such as Alzheimer's disease. A zebrafish model of tauopathies has recently been developed and characterized in terms of presence of the pathological hallmarks (i.e., neurofibrillary tangles and cell death). However, it is also necessary to validate these models for function by assessing learning and memory. The majority of tools to assess memory and learning in animal models involve visual stimuli, including color preference. The color preference of zebrafish has received little attention. To validate zebrafish as a model for color-associated-learning and memory, it is necessary to evaluate its natural preferences or any pre-existing biases towards specific colors. In the present study, we have used four different colors (red, yellow, green, and blue) to test natural color preferences of the zebrafish using two procedures: Place preference and T-maze. Results from both experiments indicate a strong aversion toward blue color relative to all other colors (red, yellow, and green) when tested in combinations. No preferences or biases were found among reds, yellows, and greens in the place preference procedure. However, red and green were equally preferred and both were preferred over yellow by zebrafish in the T-maze procedure. The results from the present study show a strong aversion towards blue color compared to red, green, and yellow, with yellow being less preferred relative to red and green. The findings from this study may underpin any further designing of color-based learning and memory paradigms or experiments involving aversion, anxiety, or fear in the zebrafish.

  16. Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Capelle, Martinus [Crucell, P.O. Box 2048, NL-2301 Leiden (Netherlands); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich, Department of Environmental Systems Science, CH-8092 Zürich (Switzerland)

    2013-10-15

    Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes.

  17. Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

    International Nuclear Information System (INIS)

    Christen, Verena; Capelle, Martinus; Fent, Karl

    2013-01-01

    Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes

  18. Overexpression of miR-19b Impairs Cardiac Development in Zebrafish by Targeting ctnnb1

    Directory of Open Access Journals (Sweden)

    Mengmeng Li

    2014-07-01

    Full Text Available Background: MicroRNAs are broadly accepted as crucial regulators of cardiovascular development, and dysregulation of their expression has been linked to cardiac disease. MicroRNA cluster miR-17-92 has been implicated in cardiac development and function, yet its defined mechanisms of action in this context are uncertain. Here, we focused on miR-19b, a key component of the miR-17-92 cluster proven to induce cardiomyocyte proliferation in vitro. We aimed to identify the biological significance of miR-19b in cardiac development and its underlying molecular mechanism of action in vivo. Methods: We micro-injected zebrafish embryos with different concentrations (0, 2, 4 and 8 μm of miR-19b mimics or a negative control, and assessed the embryo malformation rate, mortality rate, hatching rate and heart abnormalities at 72 hours post-fertilization (72 hpf. Results: We found that overexpression of miR-19b impacted left-right symmetry and cardiac development of zebrafish embryos, characterized by pericardial edema, slower heart rate and cardiac looping defects in a dose-dependent manner. Moreover, several important signaling molecules in the Wnt signaling pathway were abnormally expressed, suggesting that overexpression of miR-19b induces the inhibition of the Wnt signaling pathway by directly targeting ctnnb1. Interestingly, the deformed cardiac phenotype was partially rescued by treatment with the GSK3β inhibitor lithium chloride. Conclusion: Our findings suggest that miR-19b regulates laterality development and heart looping in zebrafish embryos by targeting ctnnb1.

  19. Zebrafish foxo3b negatively regulates canonical Wnt signaling to affect early embryogenesis.

    Directory of Open Access Journals (Sweden)

    Xun-wei Xie

    Full Text Available FOXO genes are involved in many aspects of development and vascular homeostasis by regulating cell apoptosis, proliferation, and the control of oxidative stress. In addition, FOXO genes have been showed to inhibit Wnt/β-catenin signaling by competing with T cell factor to bind to β-catenin. However, how important of this inhibition in vivo, particularly in embryogenesis is still unknown. To demonstrate the roles of FOXO genes in embryogenesis will help us to further understand their relevant physiological functions. Zebrafish foxo3b gene, an orthologue of mammalian FOXO3, was expressed maternally and distributed ubiquitously during early embryogenesis and later restricted to brain. After morpholino-mediated knockdown of foxo3b, the zebrafish embryos exhibited defects in axis and neuroectoderm formation, suggesting its critical role in early embryogenesis. The embryo-developmental marker gene staining at different stages, phenotype analysis and rescue assays revealed that foxo3b acted its role through negatively regulating both maternal and zygotic Wnt/β-catenin signaling. Moreover, we found that foxo3b could interact with zebrafish β-catenin1 and β-catenin2 to suppress their transactivation in vitro and in vivo, further confirming its role relevant to the inhibition of Wnt/β-catenin signaling. Taken together, we revealed that foxo3b played a very important role in embryogenesis and negatively regulated maternal and zygotic Wnt/β-catenin signaling by directly interacting with both β-catenin1 and β-catenin2. Our studies provide an in vivo model for illustrating function of FOXO transcription factors in embryogenesis.

  20. Fibroblast growth factor signaling is required for early somatic gonad development in zebrafish.

    Science.gov (United States)

    Leerberg, Dena M; Sano, Kaori; Draper, Bruce W

    2017-09-01

    The vertebrate ovary and testis develop from a sexually indifferent gonad. During early development of the organism, primordial germ cells (the gamete lineage) and somatic gonad cells coalesce and begin to undergo growth and morphogenesis to form this bipotential gonad. Although this aspect of development is requisite for a fertile adult, little is known about the genetic regulation of early gonadogenesis in any vertebrate. Here, we provide evidence that fibroblast growth factor (Fgf) signaling is required for the early growth phase of a vertebrate bipotential gonad. Based on mutational analysis in zebrafish, we show that the Fgf ligand 24 (Fgf24) is required for proliferation, differentiation, and morphogenesis of the early somatic gonad, and as a result, most fgf24 mutants are sterile as adults. Additionally, we describe the ultrastructural elements of the early zebrafish gonad and show that distinct somatic cell populations can be identified soon after the gonad forms. Specifically, we show that fgf24 is expressed in an epithelial population of early somatic gonad cells that surrounds an inner population of mesenchymal somatic gonad cells that are in direct contact with the germ cells, and that fgf24 is required for stratification of the somatic tissue. Furthermore, based on gene expression analysis, we find that differentiation of the inner mesenchymal somatic gonad cells into functional cell types in the larval and early juvenile-stage gonad is dependent on Fgf24 signaling. Finally, we argue that the role of Fgf24 in zebrafish is functionally analogous to the role of tetrapod FGF9 in early gonad development.

  1. Behaviour of telomere and telomerase during aging and regeneration in zebrafish.

    Directory of Open Access Journals (Sweden)

    Monique Anchelin

    Full Text Available Telomere length and telomerase activity are important factors in the pathobiology of human diseases. Age-related diseases and premature aging syndromes are characterized by short telomeres, which can compromise cell viability, whereas tumour cells can prevent telomere loss by aberrantly upregulating telomerase. The zebrafish (Danio rerio offers multiple experimental manipulation advantages over other vertebrate models and, therefore, it has been recently considered as a potential model for aging, cancer, and regeneration studies. However, it has only partially been exploited to shed light on these fundamental biological processes. The aim of this study was, therefore, to investigate telomere length and telomerase expression and activity in different strains of zebrafish obtained from different stock centres to determine whether they undergo any changes during aging and regeneration. We found that although both telomerase expression and telomere length increased from embryo to adulthood stages, they drastically declined in aged fish despite telomerase activity was detected in different tissues of old fish. In addition, we observed a weaker upregulation of telomerase expression in regenerating fins of old fish, which well correlates with their impaired regeneration capacity. Strikingly, telomeres were elongated or maintained during the fin regeneration process at all ages and after repeated amputations, likely to support high cell proliferation rates. We conclude that the expression of telomerase and telomere length are closely related during the entire life cycle of the fish and that these two parameters can be used as biomarkers of aging in zebrafish. Our results also reveal a direct relationship between the expression of telomerase, telomere length and the efficiency of tissue regeneration.

  2. Behaviour of telomere and telomerase during aging and regeneration in zebrafish.

    Science.gov (United States)

    Anchelin, Monique; Murcia, Laura; Alcaraz-Pérez, Francisca; García-Navarro, Esther M; Cayuela, María L

    2011-02-09

    Telomere length and telomerase activity are important factors in the pathobiology of human diseases. Age-related diseases and premature aging syndromes are characterized by short telomeres, which can compromise cell viability, whereas tumour cells can prevent telomere loss by aberrantly upregulating telomerase. The zebrafish (Danio rerio) offers multiple experimental manipulation advantages over other vertebrate models and, therefore, it has been recently considered as a potential model for aging, cancer, and regeneration studies. However, it has only partially been exploited to shed light on these fundamental biological processes. The aim of this study was, therefore, to investigate telomere length and telomerase expression and activity in different strains of zebrafish obtained from different stock centres to determine whether they undergo any changes during aging and regeneration. We found that although both telomerase expression and telomere length increased from embryo to adulthood stages, they drastically declined in aged fish despite telomerase activity was detected in different tissues of old fish. In addition, we observed a weaker upregulation of telomerase expression in regenerating fins of old fish, which well correlates with their impaired regeneration capacity. Strikingly, telomeres were elongated or maintained during the fin regeneration process at all ages and after repeated amputations, likely to support high cell proliferation rates. We conclude that the expression of telomerase and telomere length are closely related during the entire life cycle of the fish and that these two parameters can be used as biomarkers of aging in zebrafish. Our results also reveal a direct relationship between the expression of telomerase, telomere length and the efficiency of tissue regeneration.

  3. Functional Analysis of Nuclear Estrogen Receptors in Zebrafish Reproduction by Genome Editing Approach.

    Science.gov (United States)

    Lu, Huijie; Cui, Yong; Jiang, Liwen; Ge, Wei

    2017-07-01

    Estrogens signal through both nuclear and membrane receptors with most reported effects being mediated via the nuclear estrogen receptors (nERs). Although much work has been reported on nERs in the zebrafish, there is a lack of direct genetic evidence for their functional roles and importance in reproduction. To address this issue, we undertook this study to disrupt all three nERs in the zebrafish, namely esr1 (ERα), esr2a (ERβII), and esr2b (ERβI), by the genome-editing technology clustered regularly interspaced short palindromic repeats and its associated nuclease (CRISPR/Cas9). Using this loss-of-function genetic approach, we successfully created three mutant zebrafish lines with each nER knocked out. In addition, we also generated all possible double and triple knockouts of the three nERs. The phenotypes of these mutants in reproduction were analyzed in all single, double, and triple nER knockouts in both females and males. Surprisingly, all three single nER mutant fish lines display normal reproductive development and function in both females and males, suggesting functional redundancy among these nERs. Further analysis of double and triple knockouts showed that nERs, especially Esr2a and Esr2b, were essential for female reproduction, and loss of these two nERs led to an arrest of folliculogenesis at previtellogenic stage II followed by sex reversal from female to male. In addition, the current study also revealed a unique role for Esr2a in follicle cell proliferation and transdifferentiation, follicle growth, and chorion formation. Taken together, this study provides the most comprehensive genetic analysis for differential functions of esr1, esr2a, and esr2b in fish reproduction. Copyright © 2017 Endocrine Society.

  4. Gβ1 is required for neutrophil migration in zebrafish.

    Science.gov (United States)

    Ke, Wenfan; Ye, Ding; Mersch, Kacey; Xu, Hui; Chen, Songhai; Lin, Fang

    2017-08-01

    Signaling mediated by G protein-coupled receptors (GPCRs) is essential for the migration of cells toward chemoattractants. The recruitment of neutrophils to injured tissues in zebrafish larvae is a useful model for studying neutrophil migration and trafficking in vivo. Indeed, the study of this process led to the discovery that PI3Kγ is required for the polarity and motility of neutrophils, features that are necessary for the directed migration of these cells to wounds. However, the mechanism by which PI3Kγ is activated remains to be determined. Here we show that signaling by specifically the heterotrimeric G protein subunit Gβ1 is critical for neutrophil migration in response to wounding. In embryos treated with small-molecule inhibitors of Gβγ signaling, neutrophils failed to migrate to wound sites. Although both the Gβ1 and Gβ4 isoforms are expressed in migrating neutrophils, only deficiency for the former (morpholino-based knockdown) interfered with the directed migration of neutrophils towards wounds. The Gβ1 deficiency also impaired the ability of cells to change cell shape and reduced their general motility, defects that are similar to those in neutrophils deficient for PI3Kγ. Transplantation assays showed that the requirement for Gβ1 in neutrophil migration is cell autonomous. Finally, live imaging revealed that Gβ1 is required for polarized activation of PI3K, and for the actin dynamics that enable neutrophil migration. Collectively, our data indicate that Gβ1 signaling controls proper neutrophil migration by activating PI3K and modulating actin dynamics. Moreover, they illustrate a role for a specific Gβ isoform in chemotaxis in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. TOXICITY EVALUATION OF NEW ENGINEERED NANOMATERIALS IN ZEBRAFISH

    Directory of Open Access Journals (Sweden)

    Maria Violetta Brundo

    2016-04-01

    Full Text Available The effect of the nanoparticles on the marine organisms, depends on their size, chemical composition, surface structure, solubility and shape.In order to take advantage from their activity, preserving the surrounding environment from a possible pollution, we are trying to trap the nanoparticles into new nanomaterials. The nanomaterials tested were synthesized proposing a ground-breaking approach by an upside-down vision of the Au/TiO2nano-system to avoid the release of nanoparticles. The system was synthesized by wrapping Au nanoparticles with a thin layer of TiO2. The non-toxicity of the nano-system was established by testing the effect of the material on zebrafish larvae. Danio rerio o zebrafish was considered a excellent model for the environmental biomonitoring of aquatic environments and the Zebrafish Embryo Toxicity Test is considered an alternative method of animal test. For this reason zebrafish larvae were exposed to different concentrations of nanoparticles of TiO2 and Au and new nanomaterials. As biomarkers of exposure, we evaluated the expression of metallothioneins by immunohistochemistry analysis and western blotting analysis also. The results obtained by toxicity test showed that neither mortality as well as sublethal effects were induced by the different nanomaterials and nanoparticles tested. Only zebrafish larvae exposed to free Au nanoparticles showed a different response to anti-MT antibody. In fact, the immunolocalization analysis highlighted an increase of the metallothioneins synthesis.

  6. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish

    International Nuclear Information System (INIS)

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang; Huang, Changjiang; Yang, Dongren

    2016-01-01

    Highlights: • PFOS chronic exposure induces sex-dependent hepatic steotosis in zebrafish. • PFOS interferes with β-oxidation, lipid synthesis, and lipid hepatic export process. • Zebrafish could be used as an alternative model for PFOS chronic toxicity screening. - Abstract: Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5 μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening.

  7. Myomaker mediates fusion of fast myocytes in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Landemaine, Aurélie; Rescan, Pierre-Yves; Gabillard, Jean-Charles, E-mail: Jean-charles.gabillard@rennes.inra.fr

    2014-09-05

    Highlights: • Myomaker is transiently expressed in fast myocytes during embryonic myogenesis. • Myomaker is essential for fast myocyte fusion in zebrafish. • The function of myomaker is conserved among Teleostomi. - Abstract: Myomaker (also called Tmem8c), a new membrane activator of myocyte fusion was recently discovered in mice. Using whole mount in situ hybridization on zebrafish embryos at different stages of embryonic development, we show that myomaker is transiently expressed in fast myocytes forming the bulk of zebrafish myotome. Zebrafish embryos injected with morpholino targeted against myomaker were alive after yolk resorption and appeared morphologically normal, but they were unable to swim, even under effect of a tactile stimulation. Confocal observations showed a marked phenotype characterized by the persistence of mononucleated muscle cells in the fast myotome at developmental stages where these cells normally fuse to form multinucleated myotubes. This indicates that myomaker is essential for myocyte fusion in zebrafish. Thus, there is an evolutionary conservation of myomaker expression and function among Teleostomi.

  8. Biotransformation of ginsenosides F4 and Rg6 in zebrafish.

    Science.gov (United States)

    Shen, Wen-Wen; Zhang, Hai-Xia; Qiu, Shou-Bei; Wei, Ying-Jie; Zhu, Fen-Xia; Wang, Jing; Wang, Dan-Dan; Jia, Xiao-Bin; Tang, Dao-Quan; Chen, Bin

    2017-03-28

    Ginsenosides F 4 and Rg 6 (GF 4 and GRg 6 ), two main active components of steamed notoginseng or red ginseng, are dehydrated disaccharide saponins. In this work, biotransformation of ginsenosides F 4 and Rg 6 in zebrafish was investigated by qualitatively identifying their metabolites and then proposing their possible metabolic pathways. The prediction of possible metabolism of ginsenosides F 4 and Rg 6 using zebrafish model which can effectively simulate existing mammals model was early and quickly performed. Metabolites of ginsenosides F 4 and Rg 6 after exposing to zebrafish for 24 h were identified by Ultraperformance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry. A total of 8 and 6 metabolites of ginsenosides F 4 and Rg 6 were identified in zebrafish, respectively. Of these, 7 and 5, including M1, M3-M5, M7-M9 and N1 (N5), N2, N4 (N9), N7-N8 were reported for the first time as far as we know. The mechanisms of their biotransformation involved were further deduced to be desugarization, glucuronidation, sulfation, dehydroxylation, loss of C-17 and/or C-23 residue pathways. It was concluded that loss of rhamnose at position C-6 and glucuronidation at position C-3 in zebrafish were considered as the main physiologic and metabolic processes of ginsenosides F 4 and ginsenosides Rg 6 , respectively.

  9. Evaluation of MWNT toxic effects on daphnia and zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Olasagasti, Maider; Rainieri, Sandra [AZTI-TECNALIA, Parque Tecnologico de Bizkaia 609, 48160 Derio (Spain)], E-mail: srainieri@azti.es; Alvarez, Noelia; Vera, Carolina [INASMET-TECNALIA, Mikeletegi pasealekua, 2, Parque Tecnologico, 20009 San Sebastian (Spain)

    2009-05-01

    Organisms of daphnia (Daphnia magna) and zebrafish (Danio rerio) embryos were exposed to a range of different concentrations of COOH-functionalized MWCNT suspended in an aqueous solution of Tween 20. Immobilization of daphnia and growth retardation, inhibition and malformation of zebrafish embryos were the endpoints tested after 24 and 48 hours. Immobilization of daphnia could be observed from 3 to 16 ppm and an increasing mortality of zebrafish embryo was detected at all the concentration tested. To identify more subtle toxic effects, we took advantage of the extensive information available on the zebrafish genome and monitored by RT-PCR the expression patterns of different zebrafish genes that could act as toxicity bio-markers. At some of the concentrations tested, changes in the expression profiles of the genes examined were detected. Our results suggest that MWCNT could potentially represent a risk to human health and environment, therefore a wider range of concentrations and further testing of this molecules should be carried out to define possible limitations in their use.

  10. Influence of carbon nanotube length on toxicity to zebrafish embryos

    Directory of Open Access Journals (Sweden)

    Cheng J

    2012-07-01

    Full Text Available Jinping Cheng,1,2 Shuk Han Cheng11Department of Biology and Chemistry, City University of Hong Kong, Hong Kong; 2State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, ChinaAbstract: There is currently a large difference of opinion in nanotoxicology studies of nanomaterials. There is concern about why some studies have indicated that there is strong toxicity, while others have not. In this study, the length of carbon nanotubes greatly affected their toxicity in zebrafish embryos. Multiwalled carbon nanotubes (MWCNTs were sonicated in a nitric acid solution for 24 hours and 48 hours. The modified MWCNTs were tested in early developing zebrafish embryo. MWCNTs prepared with the longer sonication time resulted in severe developmental toxicity; however, the shorter sonication time did not induce any obvious toxicity in the tested developing zebrafish embryos. The cellular and molecular changes of the affected zebrafish embryos were studied and the observed phenotypes scored. This study suggests that length plays an important role in the in vivo toxicity of functionalized CNTs. This study will help in furthering the understanding on current differences in toxicity studies of nanomaterials.Keywords: length, carbon nanotubes, sonication, developmental toxicity, zebrafish

  11. Neurotransmitter-Regulated Regeneration in the Zebrafish Retina

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    Mahesh B. Rao

    2017-04-01

    Full Text Available Summary: Current efforts to repair damaged or diseased mammalian retinas are inefficient and largely incapable of fully restoring vision. Conversely, the zebrafish retina is capable of spontaneous regeneration upon damage using Müller glia (MG-derived progenitors. Understanding how zebrafish MG initiate regeneration may help develop new treatments that prompt mammalian retinas to regenerate. We show that inhibition of γ-aminobutyric acid (GABA signaling facilitates initiation of MG proliferation. GABA levels decrease following damage, and MG are positioned to detect decreased ambient levels and undergo dedifferentiation. Using pharmacological and genetic approaches, we demonstrate that GABAA receptor inhibition stimulates regeneration in undamaged retinas while activation inhibits regeneration in damaged retinas. : Unlike mammals, zebrafish regenerate following retina damage from a resident adult stem cell (Müller glia. Dissecting the mechanisms that zebrafish use could lead to new therapeutic targets to treat retinal diseases. Patton and colleagues have discovered a mechanism by which decreased GABA levels are sensed by Müller glia to initiate a regenerative response. Keywords: zebrafish, retina, regeneration, Müller glia, GABA

  12. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China); Huang, Changjiang, E-mail: cjhuang5711@163.com [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China); Yang, Dongren, E-mail: yangdongren@yahoo.com [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China)

    2016-07-15

    Highlights: • PFOS chronic exposure induces sex-dependent hepatic steotosis in zebrafish. • PFOS interferes with β-oxidation, lipid synthesis, and lipid hepatic export process. • Zebrafish could be used as an alternative model for PFOS chronic toxicity screening. - Abstract: Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5 μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening.

  13. Zebrafish Axenic Larvae Colonization with Human Intestinal Microbiota.

    Science.gov (United States)

    Arias-Jayo, Nerea; Alonso-Saez, Laura; Ramirez-Garcia, Andoni; Pardo, Miguel A

    2018-04-01

    The human intestine hosts a vast and complex microbial community that is vital for maintaining several functions related with host health. The processes that determine the gut microbiome composition are poorly understood, being the interaction between species, the external environment, and the relationship with the host the most feasible. Animal models offer the opportunity to understand the interactions between the host and the microbiota. There are different gnotobiotic mice or rat models colonized with the human microbiota, however, to our knowledge, there are no reports on the colonization of germ-free zebrafish with a complex human intestinal microbiota. In the present study, we have successfully colonized 5 days postfertilization germ-free zebrafish larvae with the human intestinal microbiota previously extracted from a donor and analyzed by high-throughput sequencing the composition of the transferred microbial communities that established inside the zebrafish gut. Thus, we describe for first time which human bacteria phylotypes are able to colonize the zebrafish digestive tract. Species with relevant interest because of their linkage to dysbiosis in different human diseases, such as Akkermansia muciniphila, Eubacterium rectale, Faecalibacterium prausnitzii, Prevotella spp., or Roseburia spp. have been successfully transferred inside the zebrafish digestive tract.

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

    Science.gov (United States)

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

    2015-12-01

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

  15. Zebrafish Database: Customizable, Free, and Open-Source Solution for Facility Management.

    Science.gov (United States)

    Yakulov, Toma Antonov; Walz, Gerd

    2015-12-01

    Zebrafish Database is a web-based customizable database solution, which can be easily adapted to serve both single laboratories and facilities housing thousands of zebrafish lines. The database allows the users to keep track of details regarding the various genomic features, zebrafish lines, zebrafish batches, and their respective locations. Advanced search and reporting options are available. Unique features are the ability to upload files and images that are associated with the respective records and an integrated calendar component that supports multiple calendars and categories. Built on the basis of the Joomla content management system, the Zebrafish Database is easily extendable without the need for advanced programming skills.

  16. Definition of the zebrafish genome using flow cytometry and cytogenetic mapping

    Directory of Open Access Journals (Sweden)

    Zhou Yi

    2007-06-01

    Full Text Available Abstract Background The zebrafish (Danio rerio is an important vertebrate model organism system for biomedical research. The syntenic conservation between the zebrafish and human genome allows one to investigate the function of human genes using the zebrafish model. To facilitate analysis of the zebrafish genome, genetic maps have been constructed and sequence annotation of a reference zebrafish genome is ongoing. However, the duplicative nature of teleost genomes, including the zebrafish, complicates accurate assembly and annotation of a representative genome sequence. Cytogenetic approaches provide "anchors" that can be integrated with accumulating genomic data. Results Here, we cytogenetically define the zebrafish genome by first estimating the size of each linkage group (LG chromosome using flow cytometry, followed by the cytogenetic mapping of 575 bacterial artificial chromosome (BAC clones onto metaphase chromosomes. Of the 575 BAC clones, 544 clones localized to apparently unique chromosomal locations. 93.8% of these clones were assigned to a specific LG chromosome location using fluorescence in situ hybridization (FISH and compared to the LG chromosome assignment reported in the zebrafish genome databases. Thirty-one BAC clones localized to multiple chromosomal locations in several different hybridization patterns. From these data, a refined second generation probe panel for each LG chromosome was also constructed. Conclusion The chromosomal mapping of the 575 large-insert DNA clones allows for these clones to be integrated into existing zebrafish mapping data. An accurately annotated zebrafish reference genome serves as a valuable resource for investigating the molecular basis of human diseases using zebrafish mutant models.

  17. Stressor-induced proteome alterations in zebrafish: A meta-analysis of response patterns

    Energy Technology Data Exchange (ETDEWEB)

    Groh, Ksenia J., E-mail: ksenia.groh@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf (Switzerland); ETH Zürich, Swiss Federal Institute of Technology, Department of Chemistry and Applied Biosciences, 8093 Zürich (Switzerland); Suter, Marc J.-F. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf (Switzerland); ETH Zürich, Swiss Federal Institute of Technology, Department of Environmental Systems Science, 8092 Zürich (Switzerland)

    2015-02-15

    . We suggest that the results of any differential proteomics experiment performed with zebrafish should be interpreted keeping in mind the list of the most frequent responders that we have identified. Similar reservations should apply to any other species where proteome responses are analyzed by global proteomics methods. Careful consideration of the reliability and significance of observed changes is necessary in order not to over-interpret the experimental results and to prevent the proliferation of false positive linkages between the chemical and the cellular functions it perturbs. We further discuss the implications of the identified “top lists” of frequently responding proteins and protein families, and suggest further directions for proteomics research in ecotoxicology. Apart from improving the proteome coverage, further research should focus on defining the significance of the observed stress response patterns for organism phenotypes and on searching for common upstream regulators that can be targeted by specific assays.

  18. Developmental Toxicity of Zinc Oxide Nanoparticles to Zebrafish (Danio rerio: A Transcriptomic Analysis.

    Directory of Open Access Journals (Sweden)

    Jin Soo Choi

    Full Text Available Zinc oxide nanoparticles (ZnO NPs are being utilized in an increasing number of fields and commercial applications. While their general toxicity and associated oxidative stress have been extensively studied, the toxicological pathways that they induce in developmental stages are still largely unknown. In this study, the developmental toxicity of ZnO NPs to embryonic/larval zebrafish was investigated. The transcriptional expression profiles induced by ZnO NPs were also investigated to ascertain novel genomic responses related to their specific toxicity pathway. Zebrafish embryos were exposed to 0.01, 0.1, 1, and 10 mg/L ZnO NPs for 96 h post-fertilization. The toxicity of ZnO NPs, based on their Zn concentration, was quite similar to that in embryonic/larval zebrafish exposed to corresponding ZnSO4 concentrations. Pericardial edema and yolk-sac edema were the principal malformations induced by ZnO NPs. Gene-expression profiling using microarrays demonstrated 689 genes that were differentially regulated (fold change >1.5 following exposure to ZnO NPs (498 upregulated, 191 downregulated. Several genes that were differentially regulated following ZnO NP exposure shared similar biological pathways with those observed with ZnSO4 exposure, but six genes (aicda, cyb5d1, edar, intl2, ogfrl2 and tnfsf13b associated with inflammation and the immune system responded specifically to ZnO NPs (either in the opposite direction or were unchanged in ZnSO4 exposure. Real-time reverse-transcription quantitative polymerase chain reaction confirmed that the responses of these genes to ZnO NPs were significantly different from their response to ZnSO4 exposure. ZnO NPs may affect genes related to inflammation and the immune system, resulting in yolk-sac edema and pericardia edema in embryonic/larval developmental stages. These results will assist in elucidating the mechanisms of toxicity of ZnO NPs during development of zebrafish.

  19. Stressor-induced proteome alterations in zebrafish: A meta-analysis of response patterns

    International Nuclear Information System (INIS)

    Groh, Ksenia J.; Suter, Marc J.-F.

    2015-01-01

    . We suggest that the results of any differential proteomics experiment performed with zebrafish should be interpreted keeping in mind the list of the most frequent responders that we have identified. Similar reservations should apply to any other species where proteome responses are analyzed by global proteomics methods. Careful consideration of the reliability and significance of observed changes is necessary in order not to over-interpret the experimental results and to prevent the proliferation of false positive linkages between the chemical and the cellular functions it perturbs. We further discuss the implications of the identified “top lists” of frequently responding proteins and protein families, and suggest further directions for proteomics research in ecotoxicology. Apart from improving the proteome coverage, further research should focus on defining the significance of the observed stress response patterns for organism phenotypes and on searching for common upstream regulators that can be targeted by specific assays

  20. Zebrafish P54 RNA helicases are cytoplasmic granule residents that are required for development and stress resilience

    Directory of Open Access Journals (Sweden)

    Cecilia Zampedri

    2016-10-01

    Full Text Available Stress granules are cytoplasmic foci that directly respond to the protein synthesis status of the cell. Various environmental insults, such as oxidative stress or extreme heat, block protein synthesis; consequently, mRNA will stall in translation, and stress granules will immediately form and become enriched with mRNAs. P54 DEAD box RNA helicases are components of RNA granules such as P-bodies and stress granules. We studied the expression, in cytoplasmic foci, of both zebrafish P54 RNA helicases (P54a and P54b during development and found that they are expressed in cytoplasmic granules under both normal conditions and stress conditions. In zebrafish embryos exposed to heat shock, some proportion of P54a and P54b helicases move to larger granules that exhibit the properties of genuine stress granules. Knockdown of P54a and/or P54b in zebrafish embryos produces developmental abnormalities restricted to the posterior trunk; further, these embryos do not form stress granules, and their survival upon exposure to heat-shock conditions is compromised. Our observations fit the model that cells lacking stress granules have no resilience or ability to recover once the stress has ended, indicating that stress granules play an essential role in the way organisms adapt to a changing environment.

  1. Effects of overfeeding and high-fat diet on cardiosomatic parameters and cardiac structures in young and adult zebrafish.

    Science.gov (United States)

    Vargas, Rafael; Vásquez, Isabel Cristina

    2017-12-01

    Obesity is a complex global health problem because it is a risk factor for multiple chronic pathologies such as cardiovascular, endocrine, metabolic, and neoplastic diseases. It is considered a multicausal disease, and one of the determining factors is nutritional imbalances, which include high-fat diets. In this paper, we use the zebrafish model to assess the impact of overfeeding and a high-fat diet in somatic and cardiac parameters in young and adult zebrafish. The results show that fish receiving a high-fat diet showed greater weight gain compared to fish receiving a standard fat diet. Additionally, changes in the heart, including increases in size, a change in the triangular shape of the ventricle to a globular shape, and an increase in the thickness of the trabeculae of the spongy myocardium were observed. These changes could be indicators of cardiovascular overload. The results show that there is a direct relationship between the intake of a high-fat diet and obesity, which in turn can induce cardiac changes, supporting the hypothesis of the relationship between high-fat diets and cardiovascular risk factors. Given the genetic similarity between zebrafish and humans, these results could be extrapolated to human beings, and the findings similarly highlight the importance of incorporating a balanced diet from the early life stages to reduce the risk of cardiovascular disease.

  2. Implications of exposure to dextran-coated and uncoated iron oxide nanoparticles to developmental toxicity in zebrafish

    Science.gov (United States)

    de Oliveira, Giovanna Medeiros Tavares; de Oliveira, Elisa Magno Nunes; Pereira, Talita Carneiro Brandão; Papaléo, Ricardo Meurer; Bogo, Maurício Reis

    2017-12-01

    Iron oxide nanoparticles (IONPS) have been widely investigated as a platform for a new class of multifunctional theranostic agents. They are considered biocompatible, and some formulations are already available in the market for clinical use. However, contradictory results regarding toxicity of IONPs raise a concern about the potential harm of these nanoparticles. Changes in the nanoparticle (NP) physicochemical properties or exposure media can significantly alter their behavior and, as a consequence, their toxic effects. Here, behavior and two-step RT-qPCR were employed to access the potential toxicological effects of dextran-coated IONPs (CLIO-NH2) and uncoated IONPs (UCIO) in zebrafish larvae. Animals were exposed for 7 days to NP solutions ranging from 0.1-100 μg/mL directly mixed to the system water. UCIO showed high decantation and instability in solution, altering zebrafish mortality but showing no alterations in behavior and molecular expression analysis. CLIO-NH2 exposure did not cause significant mortality or changes in hatching rate of zebrafish larvae; however, behavior and expression profiles of the group exposed to lower concentration (1 μg/mL) presented a tendency to decrease the locomotor activity and apoptotic pathway activation.

  3. Advancements in zebrafish applications for 21st century toxicology.

    Science.gov (United States)

    Garcia, Gloria R; Noyes, Pamela D; Tanguay, Robert L

    2016-05-01

    The zebrafish model is the only available high-throughput vertebrate assessment system, and it is uniquely suited for studies of in vivo cell biology. A sequenced and annotated genome has revealed a large degree of evolutionary conservation in comparison to the human genome. Due to our shared evolutionary history, the anatomical and physiological features of fish are highly homologous to humans, which facilitates studies relevant to human health. In addition, zebrafish provide a very unique vertebrate data stream that allows researchers to anchor hypotheses at the biochemical, genetic, and cellular levels to observations at the structural, functional, and behavioral level in a high-throughput format. In this review, we will draw heavily from toxicological studies to highlight advances in zebrafish high-throughput systems. Breakthroughs in transgenic/reporter lines and methods for genetic manipulation, such as the CRISPR-Cas9 system, will be comprised of reports across diverse disciplines. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Two-photon-based photoactivation in live zebrafish embryos.

    Science.gov (United States)

    Russek-Blum, Niva; Nabel-Rosen, Helit; Levkowitz, Gil

    2010-12-24

    Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic development, cellular signaling and adult physiology. In this respect, the use of multi-photon microscopy enables quantitative photoactivation of a given light responsive agent in deep tissues at a single cell resolution. As zebrafish embryos are optically transparent, their development can be monitored in vivo. These traits make the zebrafish a perfect model organism for controlling the activity of a variety of chemical agents and proteins by focused light. Here we describe the use of two-photon microscopy to induce the activation of chemically caged fluorescein, which in turn allows us to follow cell's destiny in live zebrafish embryos. We use embryos expressing a live genetic landmark (GFP) to locate and precisely target any cells of interest. This procedure can be similarly used for precise light induced activation of proteins, hormones, small molecules and other caged compounds.

  5. The neurogenetic frontier—lessons from misbehaving zebrafish

    Science.gov (United States)

    Granato, Michael

    2008-01-01

    One of the central questions in neuroscience is how refined patterns of connectivity in the brain generate and monitor behavior. Genetic mutations can influence neural circuits by disrupting differentiation or maintenance of component neuronal cells or by altering functional patterns of nervous system connectivity. Mutagenesis screens therefore have the potential to reveal not only the molecular underpinnings of brain development and function, but to illuminate the cellular basis of behavior. Practical considerations make the zebrafish an organism of choice for undertaking forward genetic analysis of behavior. The powerful array of experimental tools at the disposal of the zebrafish researcher makes it possible to link molecular function to neuronal properties that underlie behavior. This review focuses on specific challenges to isolating and analyzing behavioral mutants in zebrafish. PMID:18836206

  6. The neurogenetic frontier--lessons from misbehaving zebrafish.

    Science.gov (United States)

    Burgess, Harold A; Granato, Michael

    2008-11-01

    One of the central questions in neuroscience is how refined patterns of connectivity in the brain generate and monitor behavior. Genetic mutations can influence neural circuits by disrupting differentiation or maintenance of component neuronal cells or by altering functional patterns of nervous system connectivity. Mutagenesis screens therefore have the potential to reveal not only the molecular underpinnings of brain development and function, but to illuminate the cellular basis of behavior. Practical considerations make the zebrafish an organism of choice for undertaking forward genetic analysis of behavior. The powerful array of experimental tools at the disposal of the zebrafish researcher makes it possible to link molecular function to neuronal properties that underlie behavior. This review focuses on specific challenges to isolating and analyzing behavioral mutants in zebrafish.

  7. Expression profiles for six zebrafish genes during gonadal sex differentiation

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Morthorst, Jane Ebsen; Andersen, Ole

    2008-01-01

    BACKGROUND: The mechanism of sex determination in zebrafish is largely unknown and neither sex chromosomes nor a sex-determining gene have been identified. This indicates that sex determination in zebrafish is mediated by genetic signals from autosomal genes. The aim of this study was to determine...... the precise timing of expression of six genes previously suggested to be associated with sex differentiation in zebrafish. The current study investigates the expression of all six genes in the same individual fish with extensive sampling dates during sex determination and -differentiation. RESULTS......: In the present study, we have used quantitative real-time PCR to investigate the expression of ar, sox9a, dmrt1, fig alpha, cyp19a1a and cyp19a1b during the expected sex determination and gonadal sex differentiation period. The expression of the genes expected to be high in males (ar, sox9a and dmrt1a) and high...

  8. The Hypocretin/Orexin Neuronal Networks in Zebrafish.

    Science.gov (United States)

    Elbaz, Idan; Levitas-Djerbi, Talia; Appelbaum, Lior

    2017-01-01

    The hypothalamic Hypocretin/Orexin (Hcrt) neurons secrete two Hcrt neuropeptides. These neurons and peptides play a major role in the regulation of feeding, sleep wake cycle, reward-seeking, addiction, and stress. Loss of Hcrt neurons causes the sleep disorder narcolepsy. The zebrafish has become an attractive model to study the Hcrt neuronal network because it is a transparent vertebrate that enables simple genetic manipulation, imaging of the structure and function of neuronal circuits in live animals, and high-throughput monitoring of behavioral performance during both day and night. The zebrafish Hcrt network comprises ~16-60 neurons, which similar to mammals, are located in the hypothalamus and widely innervate the brain and spinal cord, and regulate various fundamental behaviors such as feeding, sleep, and wakefulness. Here we review how the zebrafish contributes to the study of the Hcrt neuronal system molecularly, anatomically, physiologically, and pathologically.

  9. MEK Inhibitors Reverse cAMP-Mediated Anxiety in Zebrafish

    DEFF Research Database (Denmark)

    Lundegaard, Pia R.; Anastasaki, Corina; Grant, Nicola J.

    2015-01-01

    Altered phosphodiesterase (PDE)-cyclic AMP (cAMP) activity is frequently associated with anxiety disorders, but current therapies act by reducing neuronal excitability rather than targeting PDE-cAMP-mediated signaling pathways. Here, we report the novel repositioning of anti-cancer MEK inhibitors...... as anxiolytics in a zebrafish model of anxiety-like behaviors. PDE inhibitors or activators of adenylate cyclase cause behaviors consistent with anxiety in larvae and adult zebrafish. Small-molecule screening identifies MEK inhibitors as potent suppressors of cAMP anxiety behaviors in both larvae and adult...... zebrafish, while causing no anxiolytic behavioral effects on their own. The mechanism underlying cAMP-induced anxiety is via crosstalk to activation of the RAS-MAPK signaling pathway. We propose that targeting crosstalk signaling pathways can be an effective strategy for mental health disorders, and advance...

  10. Hypoxia-induced retinopathy model in adult zebrafish

    DEFF Research Database (Denmark)

    Cao, Ziquan; Jensen, Lasse D.; Rouhi, Pegah

    2010-01-01

    Hypoxia-induced vascular responses, including angiogenesis, vascular remodeling and vascular leakage, significantly contribute to the onset, development and progression of retinopathy. However, until recently there were no appropriate animal disease models recapitulating adult retinopathy available....... In this article, we describe protocols that create hypoxia-induced retinopathy in adult zebrafish. Adult fli1: EGFP zebrafish are placed in hypoxic water for 3-10 d and retinal neovascularization is analyzed using confocal microscopy. It usually takes 11 d to obtain conclusive results using the hypoxia......-induced retinopathy model in adult zebrafish. This model provides a unique opportunity to study kinetically the development of retinopathy in adult animals using noninvasive protocols and to assess therapeutic efficacy of orally active antiangiogenic drugs....

  11. The transcriptomics of glucocorticoid receptor signaling in developing zebrafish.

    Directory of Open Access Journals (Sweden)

    Dinushan Nesan

    Full Text Available Cortisol is the primary corticosteroid in teleosts that is released in response to stressor activation of the hypothalamus-pituitary-interrenal axis. The target tissue action of this hormone is primarily mediated by the intracellular glucocorticoid receptor (GR, a ligand-bound transcription factor. In developing zebrafish (Danio rerio embryos, GR transcripts and cortisol are maternally deposited into the oocyte prior to fertilization and influence early embryogenesis. To better understand of the molecular mechanisms involved, we investigated changes in the developmental transcriptome prior to hatch, in response to morpholino oligonucleotide knockdown of GR using the Agilent zebrafish microarray platform. A total of 1313 and 836 mRNA transcripts were significantly changed at 24 and 36 hours post fertilization (hpf, respectively. Functional analysis revealed numerous developmental processes under GR regulation, including neurogenesis, eye development, skeletal and cardiac muscle formation. Together, this study underscores a critical role for glucocorticoid signaling in programming molecular events essential for zebrafish development.

  12. Alcohol impairs predation risk response and communication in zebrafish.

    Directory of Open Access Journals (Sweden)

    Thiago Acosta Oliveira

    Full Text Available The effects of ethanol exposure on Danio rerio have been studied from the perspectives of developmental biology and behavior. However, little is known about the effects of ethanol on the prey-predator relationship and chemical communication of predation risk. Here, we showed that visual contact with a predator triggers stress axis activation in zebrafish. We also observed a typical stress response in zebrafish receiving water from these conspecifics, indicating that these fish chemically communicate predation risk. Our work is the first to demonstrate how alcohol effects this prey-predator interaction. We showed for the first time that alcohol exposure completely blocks stress axis activation in both fish seeing the predator and in fish that come in indirect contact with a predator by receiving water from these conspecifics. Together with other research results and with the translational relevance of this fish species, our data points to zebrafish as a promising animal model to study human alcoholism.

  13. Morphological and Physiological Interactions Between GnRH3 and Hypocretin/Orexin Neuronal Systems in Zebrafish (Danio rerio).

    Science.gov (United States)

    Zhao, Yali; Singh, Chanpreet; Prober, David A; Wayne, Nancy L

    2016-10-01

    GnRH neurons integrate internal and external cues to control sexual maturation and fertility. Homeostasis of energy balance and food intake correlates strongly with the status of reproduction. Neuropeptides secreted by the hypothalamus involved in modulating energy balance and feeding may play additional roles in the regulation of reproduction. Hypocretin (Hcrt) (also known as orexin) is one such peptide, primarily controlling sleep/wakefulness, food intake, and reward processing. There is a growing body of evidence indicating that Hcrt/orexin (Hcrt) modulates reproduction through interacting with the hypothalamo-pituitary-gonadal axis in mammals. To explore potential morphological and functional interactions between the GnRH and Hcrt neuronal systems, we employed a variety of experimental approaches including confocal imaging, immunohistochemistry, and electrophysiology in transgenic zebrafish, in which fluorescent proteins are genetically expressed in GnRH3 and Hcrt neurons. Our imaging data revealed close apposition and direct connection between GnRH3 and Hcrt neuronal systems in the hypothalamus during larval development through adulthood. Furthermore, the Hcrt receptor (HcrtR) is expressed in GnRH3 neurons. Electrophysiological data revealed a reversible inhibitory effect of Hcrt on GnRH3 neuron electrical activity, which was blocked by the HcrtR antagonist almorexant. In addition, Hcrt had no effect on the electrical activity of GnRH3 neurons in the HcrtR null mutant zebrafish (HcrtR -/- ). Our findings demonstrate a close anatomical and functional relationship between Hcrt and GnRH neuronal systems in zebrafish. It is the first demonstration of a link between neuronal circuits controlling sleeping/arousal/feeding and reproduction in zebrafish, an important animal model for investigating the molecular genetics of development.

  14. Graph theoretical model of a sensorimotor connectome in zebrafish.

    Science.gov (United States)

    Stobb, Michael; Peterson, Joshua M; Mazzag, Borbala; Gahtan, Ethan

    2012-01-01

    Mapping the detailed connectivity patterns (connectomes) of neural circuits is a central goal of neuroscience. The best quantitative approach to analyzing connectome data is still unclear but graph theory has been used with success. We present a graph theoretical model of the posterior lateral line sensorimotor pathway in zebrafish. The model includes 2,616 neurons and 167,114 synaptic connections. Model neurons represent known cell types in zebrafish larvae, and connections were set stochastically following rules based on biological literature. Thus, our model is a uniquely detailed computational representation of a vertebrate connectome. The connectome has low overall connection density, with 2.45% of all possible connections, a value within the physiological range. We used graph theoretical tools to compare the zebrafish connectome graph to small-world, random and structured random graphs of the same size. For each type of graph, 100 randomly generated instantiations were considered. Degree distribution (the number of connections per neuron) varied more in the zebrafish graph than in same size graphs with less biological detail. There was high local clustering and a short average path length between nodes, implying a small-world structure similar to other neural connectomes and complex networks. The graph was found not to be scale-free, in agreement with some other neural connectomes. An experimental lesion was performed that targeted three model brain neurons, including the Mauthner neuron, known to control fast escape turns. The lesion decreased the number of short paths between sensory and motor neurons analogous to the behavioral effects of the same lesion in zebrafish. This model is expandable and can be used to organize and interpret a growing database of information on the zebrafish connectome.

  15. Developmental toxicity evaluation of three hexabromocyclododecane diastereoisomers on zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Du Miaomiao [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang Dandan; Yan Changzhou [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Zhang Xian, E-mail: xzhang@iue.ac.cn [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2012-05-15

    Structural dissimilarities of hexabromocyclododecane diastereoisomers could raise substantial differences in physicochemical, biological and toxicological properties. In order to fully assess the environmental safety and health risk of hexabromocyclododecanes (HBCDs), zebrafish embryos were used to evaluate the developmental toxicity of individual HBCD diastereoisomers ({alpha}-HBCD, {beta}-HBCD and {gamma}-HBCD). Four-hour post-fertilization (hpf) zebrafish embryos were exposed to different concentrations of HBCD diastereoisomers (0, 0.01, 0.1 and 1.0 mg/l) until 120 hpf. The results showed that exposure to HBCDs can affect the development of zebrafish embryos/larvae in a dose-dependent and diastereoselective manner. The diastereoisomers {alpha}-, {beta}- and {gamma}-HBCD at 0.01 mg/l had little effect on the development of zebrafish embryos except that exposure to 0.01 mg/l {gamma}-HBCD significantly delayed hatching (P < 0.05). At 0.1 mg/l, {alpha}-HBCD resulted in depressed heart rate of larvae (96 hpf) and delayed hatching, whereas {beta}- and {gamma}-HBCD both caused significant hatching delay and growth inhibition (P < 0.05). In addition, a remarkable and significant increase in mortality and malformation rate was noted at 0.1 mg/l {gamma}-HBCD exposure groups (P < 0.05). At 1.0 mg/l, {alpha}-, {beta}- and {gamma}-HBCD significantly affected all of the endpoints monitored (P < 0.05). Additionally, HBCD diastereoisomers could induce the generation of reactive oxygen species (ROS) and the activities of caspase-3 and caspase-9 in a dose-dependent manner. The results indicated that HBCD diastereoisomers could cause developmental toxicity to zebrafish embryos through inducing apoptosis by ROS formation. The overall results showed a good agreement confirming that the order of developmental toxicity of HBCD diastereoisomers in zebrafish is {gamma}-HBCD > {beta}-HBCD > {alpha}-HBCD.

  16. Defective glycinergic synaptic transmission in zebrafish motility mutants

    Directory of Open Access Journals (Sweden)

    Hiromi Hirata

    2010-01-01

    Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

  17. Disruption of the folate pathway in zebrafish causes developmental defects

    Directory of Open Access Journals (Sweden)

    Lee Marina S

    2012-04-01

    Full Text Available Abstract Background Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism during development. Results We first identified zebrafish orthologs of 12 human folate metabolic genes. RT-PCR and in situ analysis indicated maternal transcripts supply the embryo with mRNA so that the embryo has an intact folate pathway. To perturb folate metabolism we exposed zebrafish embryos to methotrexate (MTX, a potent inhibitor of dihydrofolate reductase (Dhfr an essential enzyme in the folate metabolic pathway. Embryos exposed to high doses of MTX exhibited developmental arrest prior to early segmentation. Lower doses of MTX resulted in embryos with a shortened anterior-posterior axis and cardiac defects: linear heart tubes or incomplete cardiac looping. Inhibition of dhfr mRNA with antisense morpholino oligonucleotides resulted in embryonic lethality. One function of the folate pathway is to provide essential one-carbon units for dTMP synthesis, a rate-limiting step of DNA synthesis. After 24 hours of exposure to high levels of MTX, mutant embryos continue to incorporate the thymidine analog BrdU. However, additional experiments indicate that these embryos have fewer mitotic cells, as assayed with phospho-histone H3 antibodies, and that treated embryos have perturbed cell cycles. Conclusions Our studies demonstrate that human and zebrafish utilize similar one-carbon pathways. Our data indicate that folate metabolism is essential for early zebrafish development. Zebrafish studies of the folate pathway and its deficiencies could provide insight into the underlying etiology of human birth defects and the natural role of folate in development.

  18. Graph theoretical model of a sensorimotor connectome in zebrafish.

    Directory of Open Access Journals (Sweden)

    Michael Stobb

    Full Text Available Mapping the detailed connectivity patterns (connectomes of neural circuits is a central goal of neuroscience. The best quantitative approach to analyzing connectome data is still unclear but graph theory has been used with success. We present a graph theoretical model of the posterior lateral line sensorimotor pathway in zebrafish. The model includes 2,616 neurons and 167,114 synaptic connections. Model neurons represent known cell types in zebrafish larvae, and connections were set stochastically following rules based on biological literature. Thus, our model is a uniquely detailed computational representation of a vertebrate connectome. The connectome has low overall connection density, with 2.45% of all possible connections, a value within the physiological range. We used graph theoretical tools to compare the zebrafish connectome graph to small-world, random and structured random graphs of the same size. For each type of graph, 100 randomly generated instantiations were considered. Degree distribution (the number of connections per neuron varied more in the zebrafish graph than in same size graphs with less biological detail. There was high local clustering and a short average path length between nodes, implying a small-world structure similar to other neural connectomes and complex networks. The graph was found not to be scale-free, in agreement with some other neural connectomes. An experimental lesion was performed that targeted three model brain neurons, including the Mauthner neuron, known to control fast escape turns. The lesion decreased the number of short paths between sensory and motor neurons analogous to the behavioral effects of the same lesion in zebrafish. This model is expandable and can be used to organize and interpret a growing database of information on the zebrafish connectome.

  19. Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

    Science.gov (United States)

    Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

    2009-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

  20. Expression of sall4 in taste buds of zebrafish.

    Science.gov (United States)

    Jackson, Robyn; Braubach, Oliver R; Bilkey, Jessica; Zhang, Jing; Akimenko, Marie-Andrée; Fine, Alan; Croll, Roger P; Jonz, Michael G

    2013-07-01

    We characterized the expression of sall4, a gene encoding a zinc finger transcription factor involved in the maintenance of embryonic stem cells, in taste buds of zebrafish (Danio rerio). Using an enhancer trap line (ET5), we detected enhanced green fluorescent protein (EGFP) in developing and adult transgenic zebrafish in regions containing taste buds: the lips, branchial arches, and the nasal and maxillary barbels. Localization of EGFP to taste cells of the branchial arches and lips was confirmed by co-immunolabeling with antibodies against calretinin and serotonin, and a zebrafish-derived neuronal marker (zn-12). Transgenic insertion of the ET construct into the zebrafish genome was evaluated and mapped to chromosome 23 in proximity (i.e. 23 kb) to the sall4 gene. In situ hybridization and expression analysis between 24 and 96 h post-fertilization (hpf) demonstrated that transgenic egfp expression in ET5 zebrafish was correlated with the spatial and temporal pattern of expression of sall4 in the wild-type. Expression was first observed in the central nervous system and branchial arches at 24 hpf. At 48 hpf, sall4 and egfp expression was observed in taste bud primordia surrounding the mouth and branchial arches. At 72 and 96 hpf, expression was detected in the upper and lower lips and branchial arches. Double fluorescence in situ hybridization at 3 and 10 dpf confirmed colocalization of sall4 and egfp in the lips and branchial arches. These studies reveal sall4 expression in chemosensory cells and implicate this transcription factor in the development and renewal of taste epithelia in zebrafish. Copyright © 2013 Wiley Periodicals, Inc.

  1. Toxicity of silver nanoparticles in zebrafish models

    Energy Technology Data Exchange (ETDEWEB)

    Asharani, P V; Valiyaveettil, Suresh [Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 3, 117543 (Singapore); Wu Yilian; Gong Zhiyuan [Department of Biological Sciences, National University of Singapore, Science Drive 4, 117543 (Singapore)], E-mail: chmsv@nus.edu.sg

    2008-06-25

    This study was initiated to enhance our insight on the health and environmental impact of silver nanoparticles (Ag-np). Using starch and bovine serum albumin (BSA) as capping agents, silver nanoparticles were synthesized to study their deleterious effects and distribution pattern in zebrafish embryos (Danio rerio). Toxicological endpoints like mortality, hatching, pericardial edema and heart rate were recorded. A concentration-dependent increase in mortality and hatching delay was observed in Ag-np treated embryos. Additionally, nanoparticle treatments resulted in concentration-dependent toxicity, typified by phenotypes that had abnormal body axes, twisted notochord, slow blood flow, pericardial edema and cardiac arrhythmia. Ag{sup +} ions and stabilizing agents showed no significant defects in developing embryos. Transmission electron microscopy (TEM) of the embryos demonstrated that nanoparticles were distributed in the brain, heart, yolk and blood of embryos as evident from the electron-dispersive x-ray analysis (EDS). Furthermore, the acridine orange staining showed an increased apoptosis in Ag-np treated embryos. These results suggest that silver nanoparticles induce a dose-dependent toxicity in embryos, which hinders normal development.

  2. Toxicity of silver nanoparticles in zebrafish models

    International Nuclear Information System (INIS)

    Asharani, P V; Valiyaveettil, Suresh; Wu Yilian; Gong Zhiyuan

    2008-01-01

    This study was initiated to enhance our insight on the health and environmental impact of silver nanoparticles (Ag-np). Using starch and bovine serum albumin (BSA) as capping agents, silver nanoparticles were synthesized to study their deleterious effects and distribution pattern in zebrafish embryos (Danio rerio). Toxicological endpoints like mortality, hatching, pericardial edema and heart rate were recorded. A concentration-dependent increase in mortality and hatching delay was observed in Ag-np treated embryos. Additionally, nanoparticle treatments resulted in concentration-dependent toxicity, typified by phenotypes that had abnormal body axes, twisted notochord, slow blood flow, pericardial edema and cardiac arrhythmia. Ag + ions and stabilizing agents showed no significant defects in developing embryos. Transmission electron microscopy (TEM) of the embryos demonstrated that nanoparticles were distributed in the brain, heart, yolk and blood of embryos as evident from the electron-dispersive x-ray analysis (EDS). Furthermore, the acridine orange staining showed an increased apoptosis in Ag-np treated embryos. These results suggest that silver nanoparticles induce a dose-dependent toxicity in embryos, which hinders normal development

  3. Cadmium affects retinogenesis during zebrafish embryonic development

    International Nuclear Information System (INIS)

    Hen Chow, Elly Suk; Yu Hui, Michelle Nga; Cheng, Chi Wa; Cheng, Shuk Han

    2009-01-01

    Ocular malformations are commonly observed in embryos of aquatic species after exposure to toxicants. Using zebrafish embryos as the model organism, we showed that cadmium exposure from sphere stage (4 hpf) to end of segmentation stage (24 hpf) induced microphthalmia in cadmium-treated embryos. Embryos with eye defects were then assessed for visual abilities. Cadmium-exposed embryos were behaviorally blind, showing hyperpigmentation and loss of camouflage response to light. We investigated the cellular basis of the formation of the small eyes phenotype and the induction of blindness by studying retina development and retinotectal projections. Retinal progenitors were found in cadmium-treated embryos albeit in smaller numbers. The number of retinal ganglion cells (RGC), the first class of retinal cells to differentiate during retinogenesis, was reduced, while photoreceptor cells, the last batch of retinal neurons to differentiate, were absent. Cadmium also affected the propagation of neurons in neurogenic waves. The neurons remained in the ventronasal area and failed to spread across the retina. Drastically reduced RGC axons and disrupted optic stalk showed that the optic nerves did not extend from the retina beyond the chiasm into the tectum. Our data suggested that impairment in neuronal differentiation of the retina, disruption in RGC axon formation and absence of cone photoreceptors were the causes of microphthalmia and visual impairment in cadmium-treated embryos

  4. Application of embryonic and adult zebrafish for nanotoxicity assessment.

    Science.gov (United States)

    Wang, Jiangxin; Zhu, Xiaoshan; Chen, Yongsheng; Chang, Yung

    2012-01-01

    As an emerging model for toxicological studies, zebrafish has been explored for nanotoxicity assessment. In addition to endpoint examination of embryo/fish mortality and/or developmental disorders, molecular analyses of differential gene expression have also been employed to evaluate toxic effects associated with the exposure to nanomaterials. Here, we describe zebrafish-based assays, including both embryo and adult, for evaluation of nanotoxicity caused by metal oxide nanoparticles (NPs), in particular, zinc oxide (ZnO) and titanium oxide (TiO(2)) nanoparticles.

  5. The neural basis of visual behaviors in the larval zebrafish.

    Science.gov (United States)

    Portugues, Ruben; Engert, Florian

    2009-12-01

    We review visually guided behaviors in larval zebrafish and summarise what is known about the neural processing that results in these behaviors, paying particular attention to the progress made in the last 2 years. Using the examples of the optokinetic reflex, the optomotor response, prey tracking and the visual startle response, we illustrate how the larval zebrafish presents us with a very promising model vertebrate system that allows neurocientists to integrate functional and behavioral studies and from which we can expect illuminating insights in the near future. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Fog1 is required for cardiac looping in zebrafish

    OpenAIRE

    Walton, R. Zaak; Bruce, Ashley E.E.; Olivey, Harold E.; Najib, Khalid; Johnson, Vanitha; Earley, Judy U.; Ho, Robert K.; Svensson, Eric C.

    2006-01-01

    To further our understanding of FOG gene function during cardiac development, we utilized zebrafish to examine FOG’s role in the early steps of heart morphogenesis. We identified fragments of three fog genes in the zebrafish genomic database and isolated full-length coding sequences for each of these genes by using a combination of RT-PCR and 5′-RACE. One gene was similar to murine FOG-1 (fog1), while the remaining two were similar to murine FOG-2 (fog2a and fog2b). All Fog proteins were able...

  7. UPLC/MS MS data of testosterone metabolites in human and zebrafish liver microsomes and whole zebrafish larval microsomes

    Directory of Open Access Journals (Sweden)

    Moayad Saad

    2018-02-01

    Full Text Available This article represents data regarding a study published in Toxicology in vitro entitled “ in vitro CYP-mediated drug metabolism in the zebrafish (embryo using human reference compounds” (Saad et al., 2017 [1]. Data were acquired with ultra-performance liquid chromatography – accurate mass mass spectrometry (UPLC-amMS. A full spectrum scan was conducted for the testosterone (TST metabolites from the microsomal stability assay in zebrafish and humans. The microsomal proteins were extracted from adult zebrafish male (MLM and female (FLM livers, whole body homogenates of 96 h post fertilization larvae (EM and a pool of human liver microsomes from 50 donors (HLM. Data are expressed as the abundance from the extracted ion chromatogram of the metabolites.

  8. Ribosomal protein gene knockdown causes developmental defects in zebrafish.

    Directory of Open Access Journals (Sweden)

    Tamayo Uechi

    Full Text Available The ribosomal proteins (RPs form the majority of cellular proteins and are mandatory for cellular growth. RP genes have been linked, either directly or indirectly, to various diseases in humans. Mutations in RP genes are also associated with tissue-specific phenotypes, suggesting a possible role in organ development during early embryogenesis. However, it is not yet known how mutations in a particular RP gene result in specific cellular changes, or how RP genes might contribute to human diseases. The development of animal models with defects in RP genes will be essential for studying these questions. In this study, we knocked down 21 RP genes in zebrafish by using morpholino antisense oligos to inhibit their translation. Of these 21, knockdown of 19 RPs resulted in the development of morphants with obvious deformities. Although mutations in RP genes, like other housekeeping genes, would be expected to result in nonspecific developmental defects with widespread phenotypes, we found that knockdown of some RP genes resulted in phenotypes specific to each gene, with varying degrees of abnormality in the brain, body trunk, eyes, and ears at about 25 hours post fertilization. We focused further on the organogenesis of the brain. Each knocked-down gene that affected the morphogenesis of the brain produced a different pattern of abnormality. Among the 7 RP genes whose knockdown produced severe brain phenotypes, 3 human orthologs are located within chromosomal regions that have been linked to brain-associated diseases, suggesting a possible involvement of RP genes in brain or neurological diseases. The RP gene knockdown system developed in this study could be a powerful tool for studying the roles of ribosomes in human diseases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-15

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

  10. Zebrafish heart as a model to study the integrative autonomic control of pacemaker function

    Science.gov (United States)

    Stoyek, Matthew R.; Quinn, T. Alexander; Croll, Roger P.

    2016-01-01

    The cardiac pacemaker sets the heart's primary rate, with pacemaker discharge controlled by the autonomic nervous system through intracardiac ganglia. A fundamental issue in understanding the relationship between neural activity and cardiac chronotropy is the identification of neuronal populations that control pacemaker cells. To date, most studies of neurocardiac control have been done in mammalian species, where neurons are embedded in and distributed throughout the heart, so they are largely inaccessible for whole-organ, integrative studies. Here, we establish the isolated, innervated zebrafish heart as a novel alternative model for studies of autonomic control of heart rate. Stimulation of individual cardiac vagosympathetic nerve trunks evoked bradycardia (parasympathetic activation) and tachycardia (sympathetic activation). Simultaneous stimulation of both vagosympathetic nerve trunks evoked a summative effect. Effects of nerve stimulation were mimicked by direct application of cholinergic and adrenergic agents. Optical mapping of electrical activity confirmed the sinoatrial region as the site of origin of normal pacemaker activity and identified a secondary pacemaker in the atrioventricular region. Strong vagosympathetic nerve stimulation resulted in a shift in the origin of initial excitation from the sinoatrial pacemaker to the atrioventricular pacemaker. Putative pacemaker cells in the sinoatrial and atrioventricular regions expressed adrenergic β2 and cholinergic muscarinic type 2 receptors. Collectively, we have demonstrated that the zebrafish heart contains the accepted hallmarks of vertebrate cardiac control, establishing this preparation as a viable model for studies of integrative physiological control of cardiac function by intracardiac neurons. PMID:27342878

  11. Kctd10 regulates heart morphogenesis by repressing the transcriptional activity of Tbx5a in zebrafish

    Science.gov (United States)

    Tong, Xiangjun; Zu, Yao; Li, Zengpeng; Li, Wenyuan; Ying, Lingxiao; Yang, Jing; Wang, Xin; He, Shuonan; Liu, Da; Zhu, Zuoyan; Chen, Jianming; Lin, Shuo; Zhang, Bo

    2014-01-01

    The T-box transcription factor Tbx5 (Tbx5a in zebrafish) plays a crucial role in the formation of cardiac chambers in a dose-dependent manner. Its deregulation leads to congenital heart disease. However, little is known regarding its regulation. Here we isolate a zebrafish mutant with heart malformations, called 34c. The affected gene is identified as kctd10, a member of the potassium channel tetramerization domain (KCTD)-containing family. In the mutant, the expressions of the atrioventricular canal marker genes, such as tbx2b, hyaluronan synthase 2 (has2), notch1b and bmp4, are changed. The knockdown of tbx5 rescues the ectopic expression of has2, and knockdown of either tbx5a or has2 alleviates the heart defects. We show that Kctd10 directly binds to Tbx5 to repress its transcriptional activity. Our results reveal a new essential factor for cardiac development and suggest that KCTD10 could be considered as a new causative gene of congenital heart disease.

  12. Otolith tethering in the zebrafish otic vesicle requires Otogelin and α-Tectorin.

    Science.gov (United States)

    Stooke-Vaughan, Georgina A; Obholzer, Nikolaus D; Baxendale, Sarah; Megason, Sean G; Whitfield, Tanya T

    2015-03-15

    Otoliths are biomineralised structures important for balance and hearing in fish. Their counterparts in the mammalian inner ear, otoconia, have a primarily vestibular function. Otoliths and otoconia form over sensory maculae and are attached to the otolithic membrane, a gelatinous extracellular matrix that provides a physical coupling between the otolith and the underlying sensory epithelium. In this study, we have identified two proteins required for otolith tethering in the zebrafish ear, and propose that there are at least two stages to this process: seeding and maintenance. The initial seeding step, in which otolith precursor particles tether directly to the tips of hair cell kinocilia, fails to occur in the einstein (eis) mutant. The gene disrupted in eis is otogelin (otog); mutations in the human OTOG gene have recently been identified as causative for deafness and vestibular dysfunction (DFNB18B). At later larval stages, maintenance of otolith tethering to the saccular macula is dependent on tectorin alpha (tecta) function, which is disrupted in the rolling stones (rst) mutant. α-Tectorin (Tecta) is a major constituent of the tectorial membrane in the mammalian cochlea. Mutations in the human TECTA gene can cause either dominant (DFNA8/12) or recessive (DFNB21) forms of deafness. Our findings indicate that the composition of extracellular otic membranes is highly conserved between mammals and fish, reinforcing the view that the zebrafish is an excellent model system for the study of deafness and vestibular disease. © 2015. Published by The Company of Biologists Ltd.

  13. Analysis of the dynamic co-expression network of heart regeneration in the zebrafish

    Science.gov (United States)

    Rodius, Sophie; Androsova, Ganna; Götz, Lou; Liechti, Robin; Crespo, Isaac; Merz, Susanne; Nazarov, Petr V.; de Klein, Niek; Jeanty, Céline; González-Rosa, Juan M.; Muller, Arnaud; Bernardin, Francois; Niclou, Simone P.; Vallar, Laurent; Mercader, Nadia; Ibberson, Mark; Xenarios, Ioannis; Azuaje, Francisco

    2016-05-01

    The zebrafish has the capacity to regenerate its heart after severe injury. While the function of a few genes during this process has been studied, we are far from fully understanding how genes interact to coordinate heart regeneration. To enable systematic insights into this phenomenon, we generated and integrated a dynamic co-expression network of heart regeneration in the zebrafish and linked systems-level properties to the underlying molecular events. Across multiple post-injury time points, the network displays topological attributes of biological relevance. We show that regeneration steps are mediated by modules of transcriptionally coordinated genes, and by genes acting as network hubs. We also established direct associations between hubs and validated drivers of heart regeneration with murine and human orthologs. The resulting models and interactive analysis tools are available at http://infused.vital-it.ch. Using a worked example, we demonstrate the usefulness of this unique open resource for hypothesis generation and in silico screening for genes involved in heart regeneration.

  14. Identification of Spt5 target genes in zebrafish development reveals its dual activity in vivo.

    Directory of Open Access Journals (Sweden)

    Keerthi Krishnan

    Full Text Available Spt5 is a conserved essential protein that represses or stimulates transcription elongation in vitro. Immunolocalization studies on Drosophila polytene chromosomes suggest that Spt5 is associated with many loci throughout the genome. However, little is known about the prevalence and identity of Spt5 target genes in vivo during development. Here, we identify direct target genes of Spt5 using fog(sk8 zebrafish mutant, which disrupts the foggy/spt5 gene. We identified that fog(sk8 and their wildtype siblings differentially express less than 5% of genes examined. These genes participate in diverse biological processes from stress response to cell fate specification. Up-regulated genes exhibit shorter overall gene length compared to all genes examined. Through chromatin immunoprecipitation in zebrafish embryos, we identified a subset of developmentally critical genes that are bound by both Spt5 and RNA polymerase II. The protein occupancy patterns on these genes are characteristic of both repressive and stimulatory elongation regulation. Together our findings establish Spt5 as a dual regulator of transcription elongation in vivo and identify a small but diverse set of target genes critically dependent on Spt5 during development.

  15. Earth-strength magnetic field affects the rheotactic threshold of zebrafish swimming in shoals.

    Science.gov (United States)

    Cresci, Alessandro; De Rosa, Rosario; Putman, Nathan F; Agnisola, Claudio

    2017-02-01

    Rheotaxis, the unconditioned orienting response to water currents, is a main component of fish behavior. Rheotaxis is achieved using multiple sensory systems, including visual and tactile cues. Rheotactic orientation in open or low-visibility waters might also benefit from the stable frame of reference provided by the geomagnetic field, but this possibility has not been explored before. Zebrafish (Danio rerio) form shoals living in freshwater systems with low visibility, show a robust positive rheotaxis, and respond to geomagnetic fields. Here, we investigated whether a static magnetic field in the Earth-strength range influenced the rheotactic threshold of zebrafish in a swimming tunnel. The direction of the horizontal component of the magnetic field relative to water flow influenced the rheotactic threshold of fish as part of a shoal, but not of fish tested alone. Results obtained after disabling the lateral line of shoaling individuals with Co 2+ suggest that this organ system is involved in the observed magneto-rheotactic response. These findings constitute preliminary evidence that magnetic fields influence rheotaxis and suggest new avenues for further research. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Distinct Functions of Different scl Isoforms in Zebrafish Definitive Hematopoietic Stem Cell Initiation and Maintenance

    Science.gov (United States)

    Lan, Yahui

    2011-07-01

    The establishment of entire blood system relies on the multi-potent hematopoietic stem cells (HSCs), thus identifying the molecular mechanism in HSC generation is of importance for not only complementing the fundamental knowledge in stem cell biology, but also providing insights to the regenerative therapies. Recent researches have documented the formation of nascent HSCs through a direct transition from ventral aortic endothelium, named as endothelial hematopoietic transition (EHT) process. However, the precise genetic program engaged in this process remains largely elusive. The transcription factor scl plays pivotal and conserved roles in embryonic and adult hematopoiesis from teleosts to mammals. Our lab have previously identified a new truncated scl isoform, scl-beta, which is indispensible for the specification of HSCs in the ventral wall of dorsal aorta (VDA), the zebrafish equivalent of mammalian fetal hematopoietic organ. Here we observe that, by combining time-lapse confocal imaging of transgenic zebrafish and genetic epistasis analysis, scl-beta is expressed in a subset of ventral aortic endothelial cells and critical for their forthcoming transformation to hemogenic endothelium; in contrast, runx1 is required downstream to govern the successful egress of the hemogenic endothelial cells to become naive HSCs. In addition, the traditional known full-length scl-alpha isoform is firstly evidenced to be required for the maintenance or survival of newly formed HSCs in VDA. Collectively our data has established the genetic hierarchy controlling discrete steps in the consecutive process of HSC formation from endothelial cells and further development in VDA.

  17. Zebrafish Expression Ontology of Gene Sets (ZEOGS): a tool to analyze enrichment of zebrafish anatomical terms in large gene sets.

    Science.gov (United States)

    Prykhozhij, Sergey V; Marsico, Annalisa; Meijsing, Sebastiaan H

    2013-09-01

    The zebrafish (Danio rerio) is an established model organism for developmental and biomedical research. It is frequently used for high-throughput functional genomics experiments, such as genome-wide gene expression measurements, to systematically analyze molecular mechanisms. However, the use of whole embryos or larvae in such experiments leads to a loss of the spatial information. To address this problem, we have developed a tool called Zebrafish Expression Ontology of Gene Sets (ZEOGS) to assess the enrichment of anatomical terms in large gene sets. ZEOGS uses gene expression pattern data from several sources: first, in situ hybridization experiments from the Zebrafish Model Organism Database (ZFIN); second, it uses the Zebrafish Anatomical Ontology, a controlled vocabulary that describes connected anatomical structures; and third, the available connections between expression patterns and anatomical terms contained in ZFIN. Upon input of a gene set, ZEOGS determines which anatomical structures are overrepresented in the input gene set. ZEOGS allows one for the first time to look at groups of genes and to describe them in terms of shared anatomical structures. To establish ZEOGS, we first tested it on random gene selections and on two public microarray datasets with known tissue-specific gene expression changes. These tests showed that ZEOGS could reliably identify the tissues affected, whereas only very few enriched terms to none were found in the random gene sets. Next we applied ZEOGS to microarray datasets of 24 and 72 h postfertilization zebrafish embryos treated with beclomethasone, a potent glucocorticoid. This analysis resulted in the identification of several anatomical terms related to glucocorticoid-responsive tissues, some of which were stage-specific. Our studies highlight the ability of ZEOGS to extract spatial information from datasets derived from whole embryos, indicating that ZEOGS could be a useful tool to automatically analyze gene expression

  18. Zebrafish Expression Ontology of Gene Sets (ZEOGS): A Tool to Analyze Enrichment of Zebrafish Anatomical Terms in Large Gene Sets

    Science.gov (United States)

    Marsico, Annalisa

    2013-01-01

    Abstract The zebrafish (Danio rerio) is an established model organism for developmental and biomedical research. It is frequently used for high-throughput functional genomics experiments, such as genome-wide gene expression measurements, to systematically analyze molecular mechanisms. However, the use of whole embryos or larvae in such experiments leads to a loss of the spatial information. To address this problem, we have developed a tool called Zebrafish Expression Ontology of Gene Sets (ZEOGS) to assess the enrichment of anatomical terms in large gene sets. ZEOGS uses gene expression pattern data from several sources: first, in situ hybridization experiments from the Zebrafish Model Organism Database (ZFIN); second, it uses the Zebrafish Anatomical Ontology, a controlled vocabulary that describes connected anatomical structures; and third, the available connections between expression patterns and anatomical terms contained in ZFIN. Upon input of a gene set, ZEOGS determines which anatomical structures are overrepresented in the input gene set. ZEOGS allows one for the first time to look at groups of genes and to describe them in terms of shared anatomical structures. To establish ZEOGS, we first tested it on random gene selections and on two public microarray datasets with known tissue-specific gene expression changes. These tests showed that ZEOGS could reliably identify the tissues affected, whereas only very few enriched terms to none were found in the random gene sets. Next we applied ZEOGS to microarray datasets of 24 and 72 h postfertilization zebrafish embryos treated with beclomethasone, a potent glucocorticoid. This analysis resulted in the identification of several anatomical terms related to glucocorticoid-responsive tissues, some of which were stage-specific. Our studies highlight the ability of ZEOGS to extract spatial information from datasets derived from whole embryos, indicating that ZEOGS could be a useful tool to automatically analyze gene

  19. Reversibility of endocrine disruption in zebrafish (Danio rerio) - comparison of different effect levels

    DEFF Research Database (Denmark)

    Baumann, Lisa; Holbech, Henrik; Schiller, V.S.

    : the androgen trenbolone binds directly and very effectively to the androgen receptor. Ethinylestradiol, a synthetic derivative of estradiol, causes feminization in wildlife and humans. The fungicide prochloraz acts as an aromatase inhibitor by direct interference with the aromatization of androgens......Endocrine disrupting chemicals (EDCs) exert effects at very low concentrations and can cause serious problems for the hormonal balance of various organisms. Exposure of wildlife to EDCs is not necessarily continuous, but may often occur in pulses. Consequently for the evaluation of the long......-term effects on populations, it is essential to know whether such EDC-related effects are reversible. Three different substances selected for different modes of action were tested for their long-term impact on sex ratio, gonadal development, vitellogenin (VTG) induction and aromatase activity in zebrafish...

  20. Zebrafish syntenic relationship to human/mouse genomes revealed by radiation hybrid mapping

    International Nuclear Information System (INIS)

    Samonte, Irene E.

    2007-01-01

    Zebrafish (Danio rerio) is an excellent model system for vertebrate developmental analysis and a new model for human disorders. In this study, however, zebrafish was used to determine its syntenic relationship to human/mouse genomes using the zebrafish-hamster radiation hybrid panel. The focus was on genes residing on chromosomes 6 and 17 of human and mouse, respectively, and some other genes of either immunologic or evolutionary importance. Gene sequences of interest and zebrafish expressed sequence tags deposited in the GenBank were used in identifying zebrafish homologs. Polymerase chain reaction (PCR) amplification, cloning and subcloning, sequencing, and phylogenetic analysis were done to confirm the homology of the candidate genes in zebrafish. The promising markers were then tested in the 94 zebrafish-hamster radiation hybrid panel cell lines and submitted for logarithm of the odds (LOD) score analysis to position genes on the zebrafish map. A total of 19 loci were successfully mapped to zebrafish linkage groups 1, 14, 15, 19, and 20. Four of these loci were positioned in linkage group 20, whereas, 3 more loci were added in linkage group 19, thus increasing to 34 loci the number of human genes syntenic to the group. With the sequencing of the zebrafish genome, about 20 more MHC genes were reported linked on the same group. (Author)

  1. Towards a comprehensive catalog of zebrafish behavior 1.0 and beyond.

    Science.gov (United States)

    Kalueff, Allan V; Gebhardt, Michael; Stewart, Adam Michael; Cachat, Jonathan M; Brimmer, Mallorie; Chawla, Jonathan S; Craddock, Cassandra; Kyzar, Evan J; Roth, Andrew; Landsman, Samuel; Gaikwad, Siddharth; Robinson, Kyle; Baatrup, Erik; Tierney, Keith; Shamchuk, Angela; Norton, William; Miller, Noam; Nicolson, Teresa; Braubach, Oliver; Gilman, Charles P; Pittman, Julian; Rosemberg, Denis B; Gerlai, Robert; Echevarria, David; Lamb, Elisabeth; Neuhauss, Stephan C F; Weng, Wei; Bally-Cuif, Laure; Schneider, Henning

    2013-03-01

    Zebrafish (Danio rerio) are rapidly gaining popularity in translational neuroscience and behavioral research. Physiological similarity to mammals, ease of genetic manipulations, sensitivity to pharmacological and genetic factors, robust behavior, low cost, and potential for high-throughput screening contribute to the growing utility of zebrafish models in this field. Understanding zebrafish behavioral phenotypes provides important insights into neural pathways, physiological biomarkers, and genetic underpinnings of normal and pathological brain function. Novel zebrafish paradigms continue to appear with an encouraging pace, thus necessitating a consistent terminology and improved understanding of the behavioral repertoire. What can zebrafish 'do', and how does their altered brain function translate into behavioral actions? To help address these questions, we have developed a detailed catalog of zebrafish behaviors (Zebrafish Behavior Catalog, ZBC) that covers both larval and adult models. Representing a beginning of creating a more comprehensive ethogram of zebrafish behavior, this effort will improve interpretation of published findings, foster cross-species behavioral modeling, and encourage new groups to apply zebrafish neurobehavioral paradigms in their research. In addition, this glossary creates a framework for developing a zebrafish neurobehavioral ontology, ultimately to become part of a unified animal neurobehavioral ontology, which collectively will contribute to better integration of biological data within and across species.

  2. Statistical Analysis of Zebrafish Locomotor Response.

    Science.gov (United States)

    Liu, Yiwen; Carmer, Robert; Zhang, Gaonan; Venkatraman, Prahatha; Brown, Skye Ashton; Pang, Chi-Pui; Zhang, Mingzhi; Ma, Ping; Leung, Yuk Fai

    2015-01-01

    Zebrafish larvae display rich locomotor behaviour upon external stimulation. The movement can be simultaneously tracked from many larvae arranged in multi-well plates. The resulting time-series locomotor data have been used to reveal new insights into neurobiology and pharmacology. However, the data are of large scale, and the corresponding locomotor behavior is affected by multiple factors. These issues pose a statistical challenge for comparing larval activities. To address this gap, this study has analyzed a visually-driven locomotor behaviour named the visual motor response (VMR) by the Hotelling's T-squared test. This test is congruent with comparing locomotor profiles from a time period. Different wild-type (WT) strains were compared using the test, which shows that they responded differently to light change at different developmental stages. The performance of this test was evaluated by a power analysis, which shows that the test was sensitive for detecting differences between experimental groups with sample numbers that were commonly used in various studies. In addition, this study investigated the effects of various factors that might affect the VMR by multivariate analysis of variance (MANOVA). The results indicate that the larval activity was generally affected by stage, light stimulus, their interaction, and location in the plate. Nonetheless, different factors affected larval activity differently over time, as indicated by a dynamical analysis of the activity at each second. Intriguingly, this analysis also shows that biological and technical repeats had negligible effect on larval activity. This finding is consistent with that from the Hotelling's T-squared test, and suggests that experimental repeats can be combined to enhance statistical power. Together, these investigations have established a statistical framework for analyzing VMR data, a framework that should be generally applicable to other locomotor data with similar structure.

  3. Hydroxylated PBDEs induce developmental arrest in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Usenko, Crystal Y., E-mail: Crystal_usenko@baylor.edu; Hopkins, David C.; Trumble, Stephen J., E-mail: Stephen_trumble@baylor.edu; Bruce, Erica D., E-mail: Erica_bruce@baylor.edu

    2012-07-01

    The ubiquitous spread of polybrominated diphenyl ethers (PBDEs) has led to concerns regarding the metabolites of these congeners, in particular hydroxylated PBDEs. There are limited studies regarding the biological interactions of these chemicals, yet there is some concern they may be more toxic than their parent compounds. In this study three hydroxylated PBDEs were assessed for toxicity in embryonic zebrafish: 3-OH-BDE 47, 5-OH-BDE 47, and 6-OH-BDE 47. All three congeners induced developmental arrest in a concentration-dependent manner; however, 6-OH-BDE 47 induced adverse effects at lower concentrations than the other congeners. Furthermore, all three induced cell death; however apoptosis was not observed. In short-term exposures (24–28 hours post fertilization), all hydroxylated PBDEs generated oxidative stress in the region corresponding to the cell death at 5 and 10 ppm. To further investigate the short-term effects that may be responsible for the developmental arrest observed in this study, gene regulation was assessed for embryos exposed to 0.625 ppm 6-OH-BDE 47 from 24 to 28 hpf. Genes involved in stress response, thyroid hormone regulation, and neurodevelopment were significantly upregulated compared to controls; however, genes related to oxidative stress were either unaffected or downregulated. This study suggests that hydroxylated PBDEs disrupt development, and may induce oxidative stress and potentially disrupt the cholinergic system and thyroid hormone homeostasis. -- Highlights: ► OH-PBDEs induce developmental arrest in a concentration-dependent manner. ► Hydroxyl group location influences biological interaction. ► OH-PBDEs induce oxidative stress. ► Thyroid hormone gene regulation was disrupted following exposure. ► To our knowledge, this is the first whole organism study of OH-PBDE toxicity.

  4. Abundance of the Quorum-Sensing Factor Ax21 in Four Strains of Stenotrophomonas maltophilia Correlates with Mortality Rate in a New Zebrafish Model of Infection.

    Directory of Open Access Journals (Sweden)

    Mario Ferrer-Navarro

    Full Text Available Stenotrophomonas maltophilia is a Gram-negative pathogen with emerging nosocomial incidence. Little is known about its pathogenesis and the genomic diversity exhibited by clinical isolates complicates the study of pathogenicity and virulence factors. Here, we present a strategy to identify such factors in new clinical isolates of S. maltophilia, incorporating an adult-zebrafish model of S. maltophilia infection to evaluate relative virulence coupled to 2D difference gel electrophoresis to explore underlying differences in protein expression. In this study we report upon three recent clinical isolates and use the collection strain ATCC13637 as a reference. The adult-zebrafish model shows discrimination capacity, i.e. from very low to very high mortality rates, with clinical symptoms very similar to those observed in natural S. maltophilia infections in fish. Strain virulence correlates with resistance to human serum, in agreement with previous studies in mouse and rat and therefore supporting zebrafish as a replacement model. Despite its clinical origin, the collection strain ATCC13637 showed obvious signs of attenuation in zebrafish, with null mortality. Multilocus-sequence-typing analysis revealed that the most virulent strains, UV74 and M30, exhibit the strongest genetic similitude. Differential proteomic analysis led to the identification of 38 proteins with significantly different abundance in the three clinical strains relative to the reference strain. Orthologs of several of these proteins have been already reported to have a role in pathogenesis, virulence or resistance mechanisms thus supporting our strategy. Proof of concept is further provided by protein Ax21, whose abundance is shown here to be directly proportional to mortality in the zebrafish infection model. Indeed, recent studies have demonstrated that this protein is a quorum-sensing-related virulence factor.

  5. Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology.

    Science.gov (United States)

    Zabinyakov, Nikita; Bullivant, Garrett; Cao, Feng; Fernandez Ojeda, Matilde; Jia, Zheng Ping; Wen, Xiao-Yan; Dowling, James J; Salomons, Gajja S; Mercimek-Andrews, Saadet

    2017-01-01

    Pyridoxine dependent epilepsy (PDE) is caused by likely pathogenic variants in ALDH7A1 (PDE-ALDH7A1) and inherited autosomal recessively. Neurotoxic alpha-amino adipic semialdehyde (alpha-AASA), piperideine 6-carboxylate and pipecolic acid accumulate in body fluids. Neonatal or infantile onset seizures refractory to anti-epileptic medications are clinical features. Treatment with pyridoxine, arginine and lysine-restricted diet does not normalize neurodevelopmental outcome or accumulation of neurotoxic metabolites. There is no animal model for high throughput drug screening. For this reason, we developed and characterized the first knock-out aldh7a1 zebrafish model using CRISPR-Cas9 technology. Zebrafish aldh7a1 mutants were generated by using a vector free method of CRISPR-Cas9 mutagenesis. Genotype analysis of aldh7a1 knock-out zebrafish was performed by high resolution melt analysis, direct sequencing and QIAxcel system. Electroencephalogram was performed. Alpha-AASA, piperideine 6-carboxylate and pipecolic acid, were measured by liquid chromatography-tandem mass spectrometry. Our knock-out aldh7a1 zebrafish has homozygous 5 base pair (bp) mutation in ALDH7A1. Knock-out aldh7a1 embryos have spontaneous rapid increase in locomotion and a rapid circling swim behavior earliest 8-day post fertilization (dpf). Electroencephalogram revealed large amplitude spike discharges compared to wild type. Knock-out aldh7a1 embryos have elevated alpha-AASA, piperideine 6-carboxylate and pipecolic acid compared to wild type embryos at 3 dpf. Knock-out aldh7a1 embryos showed no aldh7a1 protein by western blot compared to wild type. Our knock-out aldh7a1 zebrafish is a well characterized model for large-scale drug screening using behavioral and biochemical features and accurately recapitulates the human PDE-ALDH7A1 disease.

  6. Triazole-induced gene expression changes in the zebrafish embryo

    NARCIS (Netherlands)

    Hermsen, S.A.B.; Pronk, T.; van den Brandhof, E.J.; van der Ven, L.T.; Piersma, A.H.|info:eu-repo/dai/nl/071276947

    2012-01-01

    The zebrafish embryo is considered to provide a promising alternative test model for developmental toxicity testing. Most systems use morphological assessment of the embryos, however, microarray analyses may increase sensitivity and predictability of the test by detecting more subtle and detailed

  7. Lipid Uptake, Metabolism, and Transport in the Larval Zebrafish

    Directory of Open Access Journals (Sweden)

    Vanessa H. Quinlivan

    2017-11-01

    Full Text Available The developing zebrafish is a well-established model system for studies of energy metabolism, and is amenable to genetic, physiological, and biochemical approaches. For the first 5 days of life, nutrients are absorbed from its endogenous maternally deposited yolk. At 5 days post-fertilization, the yolk is exhausted and the larva has a functional digestive system including intestine, liver, gallbladder, pancreas, and intestinal microbiota. The transparency of the larval zebrafish, and the genetic and physiological similarity of its digestive system to that of mammals make it a promising system in which to address questions of energy homeostasis relevant to human health. For example, apolipoprotein expression and function is similar in zebrafish and mammals, and transgenic animals may be used to examine both the transport of lipid from yolk to body in the embryo, and the trafficking of dietary lipids in the larva. Additionally, despite the identification of many fatty acid and lipid transport proteins expressed by vertebrates, the cell biological processes that mediate the transport of dietary lipids from the intestinal lumen to the interior of enterocytes remain to be elucidated. Genetic tractability and amenability to live imaging and a range of biochemical methods make the larval zebrafish an ideal model in which to address open questions in the field of lipid transport, energy homeostasis, and nutrient metabolism.

  8. DNA mismatch repair, genome instability and cancer in zebrafish

    NARCIS (Netherlands)

    Feitsma, H.

    2008-01-01

    The objective of this study was to find out whether the zebrafish can be an appropriate model for studying DNA repair and cancer. For this purpose three fish lines were used that lack components of an important mechanism for the repair of small DNA damage: DNA mismatch repair. These fish are

  9. In vivo nanotoxicity testing using the zebrafish embryo assay

    Czech Academy of Sciences Publication Activity Database

    Rizzo, L. Y.; Golombek, S. K.; Mertens, M. E.; Pan, Y.; Laaf, D.; Broda, J.; Jayapaul, J.; Möckel, D.; Šubr, Vladimír; Hennink, W. E.; Storm, G.; Simon, U.; Jahnen-Dechent, W.; Kiessling, F.; Lammers, T.

    2013-01-01

    Roč. 1, č. 32 (2013), s. 3918-3925 ISSN 2050-750X R&D Projects: GA ČR GAP301/12/1254 Institutional support: RVO:61389013 Keywords : nanomaterials * zebrafish * toxicity Subject RIV: CD - Macromolecular Chemistry

  10. Automated visual tracking for studying the ontogeny of zebrafish swimming

    NARCIS (Netherlands)

    Fontaine, E.; Lentink, D.; Kranenbarg, S.; Müller, U.K.; Leeuwen, van J.L.; Barr, A.H.; Burdick, J.W.

    2008-01-01

    The zebrafish Danio rerio is a widely used model organism in studies of genetics, developmental biology, and recently, biomechanics. In order to quantify changes in swimming during all stages of development, we have developed a visual tracking system that estimates the posture of fish. Our current

  11. Early gonad development in zebrafish ( Danio rerio ) | Okuthe ...

    African Journals Online (AJOL)

    Gonadogenesis in zebrafish goes through an initial ovarian phase then subsequently into either ovarian or testicular phases. How germ cells choose to commit to an oogenic fate and enter meiosis or alternatively not enter meiosis and commit to a spermatogenetic fate remains a key question. This study investigated events ...

  12. In Vivo Nanotoxicity Testing using the Zebrafish Embryo Assay.

    Science.gov (United States)

    Rizzo, Larissa Y; Golombek, Susanne K; Mertens, Marianne E; Pan, Yu; Laaf, Dominic; Broda, Janine; Jayapaul, Jabadurai; Möckel, Diana; Subr, Vladimir; Hennink, Wim E; Storm, Gert; Simon, Ulrich; Jahnen-Dechent, Willi; Kiessling, Fabian; Lammers, Twan

    2013-06-10

    Nanoparticles are increasingly used for biomedical purposes. Many different diagnostic and therapeutic applications are envisioned for nanoparticles, but there are often also serious concerns regarding their safety. Given the fact that numerous new nanomaterials are being developed every day, and that not much is known about the long-term toxicological impact of exposure to nanoparticles, there is an urgent need to establish efficient methods for nanotoxicity testing. The zebrafish (Danio rerio) embryo assay has recently emerged as an interesting 'intermediate' method for in vivo nanotoxicity screening, enabling (semi-) high-throughput analyses in a system significantly more complex than cultured cells, but at the same time also less 'invasive' and less expensive than large-scale biocompatibility studies in mice or rats. The zebrafish embryo assay is relatively well-established in the environmental sciences, but it has not yet gained wide notice in the nanomedicine field. Using prototypic polymeric drug carriers, gold-based nanodiagnostics and nanotherapeutics, and iron oxide-based nanodiagnostics, we here show that toxicity testing using zebrafish embryos is easy, efficient and informative, and faithfully reflects, yet significantly extends, cell-based toxicity testing. We therefore expect that the zebrafish embryo assay will become a popular future tool for in vivo nanotoxicity screening.

  13. Redundant roles of PRDM family members in zebrafish craniofacial development.

    Science.gov (United States)

    Ding, Hai-Lei; Clouthier, David E; Artinger, Kristin B

    2013-01-01

    PRDM proteins are evolutionary conserved Zn-Finger transcription factors that share a characteristic protein domain organization. Previous studies have shown that prdm1a is required for the specification and differentiation of neural crest cells in the zebrafish. Here we examine other members of this family, specifically prdm3, 5, and 16, in the differentiation of the zebrafish craniofacial skeleton. prdm3 and prdm16 are strongly expressed in the pharyngeal arches, while prdm5 is expressed specifically in the area of the forming neurocranium. Knockdown of prdm3 and prdm16 results in a reduction in the neural crest markers dlx2a and barx1 and defects in both the viscerocranium and the neurocranium. The knockdown of prdm3 and prdm16 in combination is additive in the neurocranium, but not in the viscerocranium. Injection of sub-optimal doses of prdm1a with prdm3 or prdm16 Morpholinos together leads to more severe phenotypes in the viscerocranium and neurocranium. prdm5 mutants have defects in the neurocranium and prdm1a and prdm5 double mutants also show more severe phenotypes. Overall, our data reveal that prdm3, 5, and 16 are involved in the zebrafish craniofacial development and that prdm1a may interact with prdm3, 5, and 16 in the formation of the craniofacial skeleton in zebrafish. Copyright © 2012 Wiley Periodicals, Inc.

  14. Imaging Subcellular Structures in the Living Zebrafish Embryo.

    Science.gov (United States)

    Engerer, Peter; Plucinska, Gabriela; Thong, Rachel; Trovò, Laura; Paquet, Dominik; Godinho, Leanne

    2016-04-02

    In vivo imaging provides unprecedented access to the dynamic behavior of cellular and subcellular structures in their natural context. Performing such imaging experiments in higher vertebrates such as mammals generally requires surgical access to the system under study. The optical accessibility of embryonic and larval zebrafish allows such invasive procedures to be circumvented and permits imaging in the intact organism. Indeed the zebrafish is now a well-established model to visualize dynamic cellular behaviors using in vivo microscopy in a wide range of developmental contexts from proliferation to migration and differentiation. A more recent development is the increasing use of zebrafish to study subcellular events including mitochondrial trafficking and centrosome dynamics. The relative ease with which these subcellular structures can be genetically labeled by fluorescent proteins and the use of light microscopy techniques to image them is transforming the zebrafish into an in vivo model of cell biology. Here we describe methods to generate genetic constructs that fluorescently label organelles, highlighting mitochondria and centrosomes as specific examples. We use the bipartite Gal4-UAS system in multiple configurations to restrict expression to specific cell-types and provide protocols to generate transiently expressing and stable transgenic fish. Finally, we provide guidelines for choosing light microscopy methods that are most suitable for imaging subcellular dynamics.

  15. Hormetic effect induced by depleted uranium in zebrafish embryos

    International Nuclear Information System (INIS)

    Ng, C.Y.P.; Cheng, S.H.; Yu, K.N.

    2016-01-01

    Highlights: • Studied hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio). • Hormesis observed at 24 hpf for exposures to 10 μg/l of depleted U (DU). • Hormesis not observed before 30 hpf for exposures to 100 μg/l of DU. • Hormetic effect induced in zebrafish embryos in a dose-and time-dependent manner. - Abstract: The present work studied the hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio) using apoptosis as the biological endpoint. Hormetic effect is characterized by biphasic dose-response relationships showing a low-dose stimulation and a high-dose inhibition. Embryos were dechorionated at 4 h post fertilization (hpf), and were then exposed to 10 or 100 μg/l depleted uranium (DU) in uranyl acetate solutions from 5 to 6 hpf. For exposures to 10 μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20 hpf but were significantly decreased at 24 hpf, which demonstrated the presence of U-induced hormesis. For exposures to 100 μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20, 24 and 30 hpf. Hormetic effect was not shown but its occurrence between 30 and 48 hpf could not be ruled out. In conclusion, hormetic effect could be induced in zebrafish embryos in a concentration- and time-dependent manner.

  16. Finding clues to the riddle of sex determination in zebrafish

    Indian Academy of Sciences (India)

    ... to instruct retention of the ovarian fate. The mechanism and identity of this instructive signal remain unknown. We hypothesize that sex in zebrafish is a culmination of combinatorial effects of the genome, germ cells and the environment with inputs from epigenetic factors translating the biological meaning of this interaction.

  17. Mitragynine attenuates withdrawal syndrome in morphine-withdrawn zebrafish.

    Directory of Open Access Journals (Sweden)

    Beng-Siang Khor

    Full Text Available A major obstacle in treating drug addiction is the severity of opiate withdrawal syndrome, which can lead to unwanted relapse. Mitragynine is the major alkaloid compound found in leaves of Mitragyna speciosa, a plant widely used by opiate addicts to mitigate the harshness of drug withdrawal. A series of experiments was conducted to investigate the effect of mitragynine on anxiety behavior, cortisol level and expression of stress pathway related genes in zebrafish undergoing morphine withdrawal phase. Adult zebrafish were subjected to two weeks chronic morphine exposure at 1.5 mg/L, followed by withdrawal for 24 hours prior to tests. Using the novel tank diving tests, we first showed that morphine-withdrawn zebrafish display anxiety-related swimming behaviors such as decreased exploratory behavior and increased erratic movement. Morphine withdrawal also elevated whole-body cortisol levels, which confirms the phenotypic stress-like behaviors. Exposing morphine-withdrawn fish to mitragynine however attenuates majority of the stress-related swimming behaviors and concomitantly lower whole-body cortisol level. Using real-time PCR gene expression analysis, we also showed that mitragynine reduces the mRNA expression of corticotropin releasing factor receptors and prodynorphin in zebrafish brain during morphine withdrawal phase, revealing for the first time a possible link between mitragynine's ability to attenuate anxiety during opiate withdrawal with the stress-related corticotropin pathway.

  18. Hormetic effect induced by depleted uranium in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.Y.P. [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Cheng, S.H., E-mail: bhcheng@cityu.edu.hk [Department of Biomedical Sciences, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong)

    2016-06-15

    Highlights: • Studied hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio). • Hormesis observed at 24 hpf for exposures to 10 μg/l of depleted U (DU). • Hormesis not observed before 30 hpf for exposures to 100 μg/l of DU. • Hormetic effect induced in zebrafish embryos in a dose-and time-dependent manner. - Abstract: The present work studied the hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio) using apoptosis as the biological endpoint. Hormetic effect is characterized by biphasic dose-response relationships showing a low-dose stimulation and a high-dose inhibition. Embryos were dechorionated at 4 h post fertilization (hpf), and were then exposed to 10 or 100 μg/l depleted uranium (DU) in uranyl acetate solutions from 5 to 6 hpf. For exposures to 10 μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20 hpf but were significantly decreased at 24 hpf, which demonstrated the presence of U-induced hormesis. For exposures to 100 μg/l DU, the amounts of apoptotic signals in the embryos were significantly increased at 20, 24 and 30 hpf. Hormetic effect was not shown but its occurrence between 30 and 48 hpf could not be ruled out. In conclusion, hormetic effect could be induced in zebrafish embryos in a concentration- and time-dependent manner.

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

    African Journals Online (AJOL)

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

  20. Functional demonstration of adaptive immunity in zebrafish using DNA vaccination

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lorenzen, Ellen; Einer-Jensen, Katja

    Due to the well characterized genome, overall highly synteny with the human genome and its suitability for functional genomics studies, the zebrafish is considered to be an ideal animal model for basic studies of mechanisms of diseases and immunity in vertebrates including humans. While several s...

  1. Repairing quite swimmingly: advances in regenerative medicine using zebrafish.

    Science.gov (United States)

    Goessling, Wolfram; North, Trista E

    2014-07-01

    Regenerative medicine has the promise to alleviate morbidity and mortality caused by organ dysfunction, longstanding injury and trauma. Although regenerative approaches for a few diseases have been highly successful, some organs either do not regenerate well or have no current treatment approach to harness their intrinsic regenerative potential. In this Review, we describe the modeling of human disease and tissue repair in zebrafish, through the discovery of disease-causing genes using classical forward-genetic screens and by modulating clinically relevant phenotypes through chemical genetic screening approaches. Furthermore, we present an overview of those organ systems that regenerate well in zebrafish in contrast to mammalian tissue, as well as those organs in which the regenerative potential is conserved from fish to mammals, enabling drug discovery in preclinical disease-relevant models. We provide two examples from our own work in which the clinical translation of zebrafish findings is either imminent or has already proven successful. The promising results in multiple organs suggest that further insight into regenerative mechanisms and novel clinically relevant therapeutic approaches will emerge from zebrafish research in the future. © 2014. Published by The Company of Biologists Ltd.

  2. Zebrafish genetics gets the Scube on Hedgehog secretion.

    Science.gov (United States)

    Ingham, Philip W

    2012-11-15

    Inspired by a zebrafish mutation, two recent studies by Creanga and colleagues (pp. 1312-1325) and Tukachinsky and colleagues have shed new light on the way in which lipidated Hedgehog proteins are secreted and released from expressing cells, suggesting a model for the sequential action of the Disp and Scube2 proteins in this process.

  3. A Fully Automated High-Throughput Zebrafish Behavioral Ototoxicity Assay.

    Science.gov (United States)

    Todd, Douglas W; Philip, Rohit C; Niihori, Maki; Ringle, Ryan A; Coyle, Kelsey R; Zehri, Sobia F; Zabala, Leanne; Mudery, Jordan A; Francis, Ross H; Rodriguez, Jeffrey J; Jacob, Abraham

    2017-08-01

    Zebrafish animal models lend themselves to behavioral assays that can facilitate rapid screening of ototoxic, otoprotective, and otoregenerative drugs. Structurally similar to human inner ear hair cells, the mechanosensory hair cells on their lateral line allow the zebrafish to sense water flow and orient head-to-current in a behavior called rheotaxis. This rheotaxis behavior deteriorates in a dose-dependent manner with increased exposure to the ototoxin cisplatin, thereby establishing itself as an excellent biomarker for anatomic damage to lateral line hair cells. Building on work by our group and others, we have built a new, fully automated high-throughput behavioral assay system that uses automated image analysis techniques to quantify rheotaxis behavior. This novel system consists of a custom-designed swimming apparatus and imaging system consisting of network-controlled Raspberry Pi microcomputers capturing infrared video. Automated analysis techniques detect individual zebrafish, compute their orientation, and quantify the rheotaxis behavior of a zebrafish test population, producing a powerful, high-throughput behavioral assay. Using our fully automated biological assay to test a standardized ototoxic dose of cisplatin against varying doses of compounds that protect or regenerate hair cells may facilitate rapid translation of candidate drugs into preclinical mammalian models of hearing loss.

  4. Automated processing of zebrafish imaging data: a survey.

    Science.gov (United States)

    Mikut, Ralf; Dickmeis, Thomas; Driever, Wolfgang; Geurts, Pierre; Hamprecht, Fred A; Kausler, Bernhard X; Ledesma-Carbayo, María J; Marée, Raphaël; Mikula, Karol; Pantazis, Periklis; Ronneberger, Olaf; Santos, Andres; Stotzka, Rainer; Strähle, Uwe; Peyriéras, Nadine

    2013-09-01

    Due to the relative transparency of its embryos and larvae, the zebrafish is an ideal model organism for bioimaging approaches in vertebrates. Novel microscope technologies allow the imaging of developmental processes in unprecedented detail, and they enable the use of complex image-based read-outs for high-throughput/high-content screening. Such applications can easily generate Terabytes of image data, the handling and analysis of which becomes a major bottleneck in extracting the targeted information. Here, we describe the current state of the art in computational image analysis in the zebrafish system. We discuss the challenges encountered when handling high-content image data, especially with regard to data quality, annotation, and storage. We survey methods for preprocessing image data for further analysis, and describe selected examples of automated image analysis, including the tracking of cells during embryogenesis, heartbeat detection, identification of dead embryos, recognition of tissues and anatomical landmarks, and quantification of behavioral patterns of adult fish. We review recent examples for applications using such methods, such as the comprehensive analysis of cell lineages during early development, the generation of a three-dimensional brain atlas of zebrafish larvae, and high-throughput drug screens based on movement patterns. Finally, we identify future challenges for the zebrafish image analysis community, notably those concerning the compatibility of algorithms and data formats for the assembly of modular analysis pipelines.

  5. Melatonin mitigates neomycin-induced hair cell injury in zebrafish.

    Science.gov (United States)

    Oh, Kyoung Ho; Rah, Yoon Chan; Hwang, Kyu Ho; Lee, Seung Hoon; Kwon, Soon Young; Cha, Jae Hyung; Choi, June

    2017-10-01

    Ototoxicity due to medications, such as aminoglycosides, is irreversible, and free radicals in the inner ear are assumed to play a major role. Because melatonin has an antioxidant property, we hypothesize that it might mitigate hair cell injury by aminoglycosides. The objective of this study was to evaluate whether melatonin has an alleviative effect on neomycin-induced hair cell injury in zebrafish (Danio rerio). Various concentrations of melatonin were administered to 5-day post-fertilization zebrafish treated with 125 μM neomycin for 1 h. Surviving hair cells within four neuromasts were compared with that of a control group. Apoptosis was assessed via terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The changes of ultrastructure were confirmed using a scanning electron microscope. Melatonin alleviated neomycin-induced hair cell injury in neuromasts (neomycin + melatonin 100 μM: 13.88 ± 0.91 cells, neomycin only: 7.85 ± 0.90 cells; n = 10, p melatonin for 1 h in SEM findings. Melatonin is effective in alleviating aminoglycoside-induced hair cell injury in zebrafish. The results of this study demonstrated that melatonin has the potential to reduce apoptosis induced by aminoglycosides in zebrafish.

  6. Egfl6 is involved in zebrafish notochord development.

    Science.gov (United States)

    Wang, Xueqian; Wang, Xin; Yuan, Wei; Chai, Renjie; Liu, Dong

    2015-08-01

    The epidermal growth factor (EGF) repeat motif defines a superfamily of diverse protein involved in regulating a variety of cellular and physiological processes, such as cell cycle, cell adhesion, proliferation, migration, and neural development. Egfl6, an EGF protein, also named MAGE was first cloned in human tissue. Up to date, the study of zebrafish Egfl6 expression pattern and functional analysis of Egfl6 involved in embryonic development of vertebrate in vivo is thus far lacking. Here we reported that Egfl6 was involved in zebrafish notochord development. It was shown that Egfl6 mRNA was expressed in zebrafish, developing somites, fin epidermis, pharyngeal arches, and hindbrain region. Particularly the secreted Egfl6 protein was significantly accumulated in notochord. Loss of Egfl6 function in zebrafish embryos resulted in curved body with distorted notochord in the posterior trunk. It was observed that expression of all Notch ligand and receptors in notochord of 28 hpf Egfl6 morphants was not affected, except notch2, which was up-regulated. We found that inhibition of Notch signaling by DAPT efficiently rescued notochord developmental defect of Egfl6 deficiency embryos.

  7. Behavioral Changes Over Time Following Ayahuasca Exposure in Zebrafish.

    Science.gov (United States)

    Savoldi, Robson; Polari, Daniel; Pinheiro-da-Silva, Jaquelinne; Silva, Priscila F; Lobao-Soares, Bruno; Yonamine, Mauricio; Freire, Fulvio A M; Luchiari, Ana C

    2017-01-01

    The combined infusion of Banisteriopsis caapi stem and Psychotria viridis leaves, known as ayahuasca, has been used for centuries by indigenous tribes. The infusion is rich in N , N -dimethyltryptamine (DMT) and monoamine oxidase inhibitors, with properties similar to those of serotonin. Despite substantial progress in the development of new drugs to treat anxiety and depression, current treatments have several limitations. Alternative drugs, such as ayahuasca, may shed light on these disorders. Here, we present time-course behavioral changes induced by ayahuasca in zebrafish, as first step toward establishing an ideal concentration for pre-clinical evaluations. We exposed adult zebrafish to five concentrations of the ayahuasca infusion: 0 (control), 0.1, 0.5, 1, and 3 ml/L ( n = 14 each group), and behavior was recorded for 60 min. We evaluated swimming speed, distance traveled, freezing and bottom dwelling every min for 60 min. Swimming speed and distance traveled decreased with an increase in ayahuasca concentration while freezing increased with 1 and 3 ml/L. Bottom dwelling increased with 1 and 3 ml/L, but declined with 0.1 ml/L. Our data suggest that small amounts of ayahuasca do not affect locomotion and reduce anxiety-like behavior in zebrafish, while increased doses of the drug lead to crescent anxiogenic effects. We conclude that the temporal analysis of zebrafish behavior is a sensitive method for the study of ayahuasca-induced functional changes in the vertebrate brain.

  8. Cell fate determination in zebrafish embryonic and adult muscle development

    NARCIS (Netherlands)

    Tee, J.M.

    2010-01-01

    We are interested in how the genetic basis of muscle precursor cells determines the outcome of the muscle cell fate, and thus leading to disruption in muscle formation and maintenance. We utilized the zebrafish carrying mutations in both Axin1 and Apc1, resulting in overactivation of the

  9. Automated Processing of Zebrafish Imaging Data: A Survey

    Science.gov (United States)

    Dickmeis, Thomas; Driever, Wolfgang; Geurts, Pierre; Hamprecht, Fred A.; Kausler, Bernhard X.; Ledesma-Carbayo, María J.; Marée, Raphaël; Mikula, Karol; Pantazis, Periklis; Ronneberger, Olaf; Santos, Andres; Stotzka, Rainer; Strähle, Uwe; Peyriéras, Nadine

    2013-01-01

    Abstract Due to the relative transparency of its embryos and larvae, the zebrafish is an ideal model organism for bioimaging approaches in vertebrates. Novel microscope technologies allow the imaging of developmental processes in unprecedented detail, and they enable the use of complex image-based read-outs for high-throughput/high-content screening. Such applications can easily generate Terabytes of image data, the handling and analysis of which becomes a major bottleneck in extracting the targeted information. Here, we describe the current state of the art in computational image analysis in the zebrafish system. We discuss the challenges encountered when handling high-content image data, especially with regard to data quality, annotation, and storage. We survey methods for preprocessing image data for further analysis, and describe selected examples of automated image analysis, including the tracking of cells during embryogenesis, heartbeat detection, identification of dead embryos, recognition of tissues and anatomical landmarks, and quantification of behavioral patterns of adult fish. We review recent examples for applications using such methods, such as the comprehensive analysis of cell lineages during early development, the generation of a three-dimensional brain atlas of zebrafish larvae, and high-throughput drug screens based on movement patterns. Finally, we identify future challenges for the zebrafish image analysis community, notably those concerning the compatibility of algorithms and data formats for the assembly of modular analysis pipelines. PMID:23758125

  10. Ontogeny of Classical and Operant Learning Behaviors in Zebrafish

    Science.gov (United States)

    Valente, Andre; Huang, Kuo-Hua; Portugues, Ruben; Engert, Florian

    2012-01-01

    The performance of developing zebrafish in both classical and operant conditioning assays was tested with a particular focus on the emergence of these learning behaviors during development. Strategically positioned visual cues paired with electroshocks were used in two fully automated assays to investigate both learning paradigms. These allow the…

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

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

  12. Behavioral Changes Over Time Following Ayahuasca Exposure in Zebrafish

    Directory of Open Access Journals (Sweden)

    Robson Savoldi

    2017-07-01

    Full Text Available The combined infusion of Banisteriopsis caapi stem and Psychotria viridis leaves, known as ayahuasca, has been used for centuries by indigenous tribes. The infusion is rich in N, N-dimethyltryptamine (DMT and monoamine oxidase inhibitors, with properties similar to those of serotonin. Despite substantial progress in the development of new drugs to treat anxiety and depression, current treatments have several limitations. Alternative drugs, such as ayahuasca, may shed light on these disorders. Here, we present time-course behavioral changes induced by ayahuasca in zebrafish, as first step toward establishing an ideal concentration for pre-clinical evaluations. We exposed adult zebrafish to five concentrations of the ayahuasca infusion: 0 (control, 0.1, 0.5, 1, and 3 ml/L (n = 14 each group, and behavior was recorded for 60 min. We evaluated swimming speed, distance traveled, freezing and bottom dwelling every min for 60 min. Swimming speed and distance traveled decreased with an increase in ayahuasca concentration while freezing increased with 1 and 3 ml/L. Bottom dwelling increased with 1 and 3 ml/L, but declined with 0.1 ml/L. Our data suggest that small amounts of ayahuasca do not affect locomotion and reduce anxiety-like behavior in zebrafish, while increased doses of the drug lead to crescent anxiogenic effects. We conclude that the temporal analysis of zebrafish behavior is a sensitive method for the study of ayahuasca-induced functional changes in the vertebrate brain.

  13. HCV IRES-mediated core expression in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ye Zhao

    Full Text Available The lack of small animal models for hepatitis C virus has impeded the discovery and development of anti-HCV drugs. HCV-IRES plays an important role in HCV gene expression, and is an attractive target for antiviral therapy. In this study, we report a zebrafish model with a biscistron expression construct that can co-transcribe GFP and HCV-core genes by human hepatic lipase promoter and zebrafish liver fatty acid binding protein enhancer. HCV core translation was designed mediated by HCV-IRES sequence and gfp was by a canonical cap-dependent mechanism. Results of fluorescence image and in situ hybridization indicate that expression of HCV core and GFP is liver-specific; RT-PCR and Western blotting show that both core and gfp expression are elevated in a time-dependent manner for both transcription and translation. It means that the HCV-IRES exerted its role in this zebrafish model. Furthermore, the liver-pathological impact associated with HCV-infection was detected by examination of gene markers and some of them were elevated, such as adiponectin receptor, heparanase, TGF-β, PDGF-α, etc. The model was used to evaluate three clinical drugs, ribavirin, IFNα-2b and vitamin B12. The results show that vitamin B12 inhibited core expression in mRNA and protein levels in dose-dependent manner, but failed to impact gfp expression. Also VB12 down-regulated some gene transcriptions involved in fat liver, liver fibrosis and HCV-associated pathological process in the larvae. It reveals that HCV-IRES responds to vitamin B12 sensitively in the zebrafish model. Ribavirin did not disturb core expression, hinting that HCV-IRES is not a target site of ribavirin. IFNα-2b was not active, which maybe resulted from its degradation in vivo for the long time. These findings demonstrate the feasibility of the zebrafish model for screening of anti-HCV drugs targeting to HCV-IRES. The zebrafish system provides a novel evidence of using zebrafish as a HCV model organism.

  14. Elucidating the mechanism of action of tributyltin (TBT) in zebrafish.

    Science.gov (United States)

    McGinnis, Courtney L; Crivello, Joseph F

    2011-05-01

    Tributyltin (TBT), an antifouling agent, has been implicated in the masculinization of fish species worldwide, but the masculinizing mechanism is not fully understood. We have examined the actions of TBT as an endocrine disruptor in zebrafish (Danio rerio). In HeLa cells transiently co-transfected with plasmid constructs containing the zebrafish estrogen receptors (zfERα, zfERβ(1) and zfERβ(2)) and the zebrafish estrogen response element (zfERE-tk-luc), ethinyl estradiol (EE2) induced luciferase activity 4 to 6-fold and was inhibited by TBT. In HeLa cells transiently co-transfected with the zebrafish androgen receptor (zfAR) and the murine androgen receptor response element (ARE-slp-luc), testosterone induced luciferase activity was not inhibited by TBT. In HeLa cells co-transfected with zfERα, zfERβ(1) and zfERβ(2) and a plasmid containing zebrafish aromatase (zfCyp19b-luc), TBT inhibited luciferase activity. In zebrafish exposed to 1mg/kg and 5mg/kg TBT in vivo, there was a increase in liver sulfotransferase and a decrease acyl-CoA testosterone acyltransferase activity. Real-time PCR analysis of sexual differentiation markers in fish exposed to TBT in vivo revealed a tissue-specific response. In brain there was increased production of Sox9, Dax1, and SF1 mRNA, an androgenizing effect, while in the liver there was increased production of Dax1, Cyp19a and zfERβ(1) mRNA but decreased production of Sox9 mRNA, a feminizing effect. In the gonads there was increased production of zfERα and zfCyp19a mRNA, again a feminizing effect. TBT has an overall masculinizing effect but the masculinizing effect is tempered by a feminizing effect on gene transcription in certain tissues. These results are discussed in the context of TBT as an endocrine disruptor in zebrafish. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Zebrafish: a model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics.

    Science.gov (United States)

    Bourdineaud, Jean-Paul; Rossignol, R; Brèthes, D

    2013-01-01

    50 nm) was investigated at a very low dose for 60 days (40 ng gold/fish/day). Mitochondrial dysfunctions appeared in brain and muscle for both tested sizes. In conclusion, at low environmental doses, dietary or waterborne heavy metals impinged on zebrafish tissue mitochondrial respiration. Due to its incredible simplicity avoiding tedious and time-consuming mitochondria isolation, our one-pot method allowing brain respiratory analysis should give colleagues the incentive to use zebrafish brain as a model in bioenergetics. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Developmental nephrotoxicity of aristolochic acid in a zebrafish model

    International Nuclear Information System (INIS)

    Ding, Yu-Ju; Chen, Yau-Hung

    2012-01-01

    Aristolochic acid (AA) is a component of Aristolochia plant extracts which is used as a treatment for different pathologies and their toxicological effects have not been sufficiently studied. The aim of this study was to evaluate AA-induced nephrotoxicity in zebrafish embryos. After soaking zebrafish embryos in AA, the embryos displayed malformed kidney phenotypes, such as curved, cystic pronephric tubes, pronephric ducts, and cases of atrophic glomeruli. The percentages of embryos with malformed kidney phenotypes increased as the exposure dosages of AA increased. Furthermore, AA-treated embryos exhibited significantly reduced glomerular filtration rates (GFRs) in comparison with mock-control littermates (mock-control: 100 ± 2.24% vs. 10 ppm AA treatment for 3–5 h: 71.48 ± 18.84% ∼ 39.41 ± 15.88%), indicating that AA treatment not only caused morphological kidney changes but also induced renal failure. In addition to kidney malformations, AA-treated zebrafish embryos also exhibited deformed hearts, swollen pericardiums, impaired blood circulation and the accumulation(s) of red blood cells. Whole-mount in situ hybridization studies using cmlc2 and wt1b as riboprobes indicated that the kidney is more sensitive than the heart to AA damage. Real-time PCR showed that AA can up-regulate the expression of proinflammatory genes like TNFα, cox2 and mpo. These results support the following conclusions: (1) AA-induced renal failure is mediated by inflammation, which causes circulation dysfunction followed by serious heart malformation; and (2) the kidney is more sensitive than the heart to AA injury. -- Highlights: ► Zebrafish were used to evaluate aristolochic acid (AA)-induced nephrotoxicity. ► AA-treated zebrafish embryos exhibited deformed heart as well as malformed kidney. ► Kidney is more sensitive to AA injury than the heart.

  17. Developmental nephrotoxicity of aristolochic acid in a zebrafish model

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yu-Ju; Chen, Yau-Hung, E-mail: yauhung@mail.tku.edu.tw

    2012-05-15

    Aristolochic acid (AA) is a component of Aristolochia plant extracts which is used as a treatment for different pathologies and their toxicological effects have not been sufficiently studied. The aim of this study was to evaluate AA-induced nephrotoxicity in zebrafish embryos. After soaking zebrafish embryos in AA, the embryos displayed malformed kidney phenotypes, such as curved, cystic pronephric tubes, pronephric ducts, and cases of atrophic glomeruli. The percentages of embryos with malformed kidney phenotypes increased as the exposure dosages of AA increased. Furthermore, AA-treated embryos exhibited significantly reduced glomerular filtration rates (GFRs) in comparison with mock-control littermates (mock-control: 100 ± 2.24% vs. 10 ppm AA treatment for 3–5 h: 71.48 ± 18.84% ∼ 39.41 ± 15.88%), indicating that AA treatment not only caused morphological kidney changes but also induced renal failure. In addition to kidney malformations, AA-treated zebrafish embryos also exhibited deformed hearts, swollen pericardiums, impaired blood circulation and the accumulation(s) of red blood cells. Whole-mount in situ hybridization studies using cmlc2 and wt1b as riboprobes indicated that the kidney is more sensitive than the heart to AA damage. Real-time PCR showed that AA can up-regulate the expression of proinflammatory genes like TNFα, cox2 and mpo. These results support the following conclusions: (1) AA-induced renal failure is mediated by inflammation, which causes circulation dysfunction followed by serious heart malformation; and (2) the kidney is more sensitive than the heart to AA injury. -- Highlights: ► Zebrafish were used to evaluate aristolochic acid (AA)-induced nephrotoxicity. ► AA-treated zebrafish embryos exhibited deformed heart as well as malformed kidney. ► Kidney is more sensitive to AA injury than the heart.

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

    Science.gov (United States)

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

    2016-02-01

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

  19. Modeling tuberculous meningitis in zebrafish using Mycobacterium marinum

    Directory of Open Access Journals (Sweden)

    Lisanne M. van Leeuwen

    2014-09-01

    Full Text Available Tuberculous meningitis (TBM is one of the most severe extrapulmonary manifestations of tuberculosis, with a high morbidity and mortality. Characteristic pathological features of TBM are Rich foci, i.e. brain- and spinal-cord-specific granulomas formed after hematogenous spread of pulmonary tuberculosis. Little is known about the early pathogenesis of TBM and the role of Rich foci. We have adapted the zebrafish model of Mycobacterium marinum infection (zebrafish–M. marinum model to study TBM. First, we analyzed whether TBM occurs in adult zebrafish and showed that intraperitoneal infection resulted in granuloma formation in the meninges in 20% of the cases, with occasional brain parenchyma involvement. In zebrafish embryos, bacterial infiltration and clustering of infected phagocytes was observed after infection at three different inoculation sites: parenchyma, hindbrain ventricle and caudal vein. Infection via the bloodstream resulted in the formation of early granulomas in brain tissue in 70% of the cases. In these zebrafish embryos, infiltrates were located in the proximity of blood vessels. Interestingly, no differences were observed when embryos were infected before or after early formation of the blood-brain barrier (BBB, indicating that bacteria are able to cross this barrier with relatively high efficiency. In agreement with this observation, infected zebrafish larvae also showed infiltration of the brain tissue. Upon infection of embryos with an M. marinum ESX-1 mutant, only small clusters and scattered isolated phagocytes with high bacterial loads were present in the brain tissue. In conclusion, our adapted zebrafish–M. marinum infection model for studying granuloma formation in the brain will allow for the detailed analysis of both bacterial and host factors involved in TBM. It will help solve longstanding questions on the role of Rich foci and potentially contribute to the development of better diagnostic tools and therapeutics.

  20. Pbx and Prdm1a transcription factors differentially regulate subsets of the fast skeletal muscle program in zebrafish

    Directory of Open Access Journals (Sweden)

    Zizhen Yao

    2013-04-01

    The basic helix–loop–helix factor Myod initiates skeletal muscle differentiation by directly and sequentially activating sets of muscle differentiation genes, including those encoding muscle contractile proteins. We hypothesize that Pbx homeodomain proteins direct Myod to a subset of its transcriptional targets, in particular fast-twitch muscle differentiation genes, thereby regulating the competence of muscle precursor cells to differentiate. We have previously shown that Pbx proteins bind with Myod on the promoter of the zebrafish fast muscle gene mylpfa and that Pbx proteins are required for Myod to activate mylpfa expression and the fast-twitch muscle-specific differentiation program in zebrafish embryos. Here we have investigated the interactions of Pbx with another muscle fiber-type regulator, Prdm1a, a SET-domain DNA-binding factor that directly represses mylpfa expression and fast muscle differentiation. The prdm1a mutant phenotype, early and increased fast muscle differentiation, is the opposite of the Pbx-null phenotype, delayed and reduced fast muscle differentiation. To determine whether Pbx and Prdm1a have opposing activities on a common set of genes, we used RNA-seq analysis to globally assess gene expression in zebrafish embryos with single- and double-losses-of-function for Pbx and Prdm1a. We find that the levels of expression of certain fast muscle genes are increased or approximately wild type in pbx2/4-MO;prdm1a−/− embryos, suggesting that Pbx activity normally counters the repressive action of Prdm1a for a subset of the fast muscle program. However, other fast muscle genes require Pbx but are not regulated by Prdm1a. Thus, our findings reveal that subsets of the fast muscle program are differentially regulated by Pbx and Prdm1a. Our findings provide an example of how Pbx homeodomain proteins act in a balance with other transcription factors to regulate subsets of a cellular differentiation program.

  1. Mutagenesis and phenotyping resources in zebrafish for studying development and human disease

    Science.gov (United States)

    Varshney, Gaurav Kumar

    2014-01-01

    The zebrafish (Danio rerio) is an important model organism for studying development and human disease. The zebrafish has an excellent reference genome and the functions of hundreds of genes have been tested using both forward and reverse genetic approaches. Recent years have seen an increasing number of large-scale mutagenesis projects and the number of mutants or gene knockouts in zebrafish has increased rapidly, including for the first time conditional knockout technologies. In addition, targeted mutagenesis techniques such as zinc finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short sequences (CRISPR) or CRISPR-associated (Cas), have all been shown to effectively target zebrafish genes as well as the first reported germline homologous recombination, further expanding the utility and power of zebrafish genetics. Given this explosion of mutagenesis resources, it is now possible to perform systematic, high-throughput phenotype analysis of all zebrafish gene knockouts. PMID:24162064

  2. Developmental social isolation affects adult behavior, social interaction, and dopamine metabolite levels in zebrafish.

    Science.gov (United States)

    Shams, Soaleha; Amlani, Shahid; Buske, Christine; Chatterjee, Diptendu; Gerlai, Robert

    2018-01-01

    The zebrafish is a social vertebrate and an excellent translational model for a variety of human disorders. Abnormal social behavior is a hallmark of several human brain disorders. Social behavioral problems can arise as a result of adverse early social environment. Little is known about the effects of early social isolation in adult zebrafish. We compared zebrafish that were isolated for either short (7 days) or long duration (180 days) to socially housed zebrafish, testing their behavior across ontogenesis (ages 10, 30, 60, 90, 120, 180 days), and shoal cohesion and whole-brain monoamines and their metabolites in adulthood. Long social isolation increased locomotion and decreased shoal cohesion and anxiety in the open-field in adult. Additionally, both short and long social isolation reduced dopamine metabolite levels in response to social stimuli. Thus, early social isolation has lasting effects in zebrafish, and may be employed to generate zebrafish models of human neuropsychiatric conditions. © 2017 Wiley Periodicals, Inc.

  3. The HDAC Inhibitor TSA Ameliorates a Zebrafish Model of Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Johnson, Nathan M; Farr, Gist H; Maves, Lisa

    2013-09-17

    Zebrafish are an excellent model for Duchenne muscular dystrophy. In particular, zebrafish provide a system for rapid, easy, and low-cost screening of small molecules that can ameliorate muscle damage in dystrophic larvae. Here we identify an optimal anti-sense morpholino cocktail that robustly knocks down zebrafish Dystrophin (dmd-MO). We use two approaches, muscle birefringence and muscle actin expression, to quantify muscle damage and show that the dmd-MO dystrophic phenotype closely resembles the zebrafish dmd mutant phenotype. We then show that the histone deacetylase (HDAC) inhibitor TSA, which has been shown to ameliorate the mdx mouse Duchenne model, can rescue muscle fiber damage in both dmd-MO and dmd mutant larvae. Our study identifies optimal morpholino and phenotypic scoring approaches for dystrophic zebrafish, further enhancing the zebrafish dmd model for rapid and cost-effective small molecule screening.

  4. Maternal stress-associated cortisol stimulation may protect embryos from cortisol excess in zebrafish

    OpenAIRE

    Faught, Erin; Best, Carol; Vijayan, Mathilakath M.

    2016-01-01

    Abnormal embryo cortisol level causes developmental defects and poor survival in zebrafish (Danio rerio). However, no study has demonstrated that maternal stress leads to higher embryo cortisol content in zebrafish. We tested the hypothesis that maternal stress-associated elevation in cortisol levels increases embryo cortisol content in this asynchronous breeder. Zebrafish mothers were fed cortisol-spiked food for 5 days, to mimic maternal stress, followed by daily breeding for 10 days to mon...

  5. Capturing tissue repair in zebrafish larvae with time-lapse brightfield stereomicroscopy.

    Science.gov (United States)

    Lisse, Thomas S; Brochu, Elizabeth A; Rieger, Sandra

    2015-01-31

    The zebrafish larval tail fin is ideal for studying tissue regeneration due to the simple architecture of the larval fin-fold, which comprises of two layers of skin that enclose undifferentiated mesenchyme, and because the larval tail fin regenerates rapidly within 2-3 days. Using this system, we demonstrate a method for capturing the repair dynamics of the amputated tail fin with time-lapse video brightfield stereomicroscopy. We demonstrate that fin amputation triggers a contraction of the amputation wound and extrusion of cells around the wound margin, leading to their subsequent clearance. Fin regeneration proceeds from proximal to distal direction after a short delay. In addition, developmental growth of the larva can be observed during all stages. The presented method provides an opportunity for observing and analyzing whole tissue-scale behaviors such as fin development and growth in a simple microscope setting, which is easily adaptable to any stereomicroscope with time-lapse capabilities.

  6. The Importance of Stochastic Effects for Explaining Entrainment in the Zebrafish Circadian Clock

    Directory of Open Access Journals (Sweden)

    Raphaela Heussen

    2015-01-01

    Full Text Available The circadian clock plays a pivotal role in modulating physiological processes and has been implicated, either directly or indirectly, in a range of pathological states including cancer. Here we investigate how the circadian clock is entrained by external cues such as light. Working with zebrafish cell lines and combining light pulse experiments with simulation efforts focused on the role of synchronization effects, we find that even very modest doses of light exposure are sufficient to trigger some entrainment, whereby a higher light intensity or duration correlates with strength of the circadian signal. Moreover, we observe in the simulations that stochastic effects may be considered an essential feature of the circadian clock in order to explain the circadian signal decay in prolonged darkness, as well as light initiated resynchronization as a strong component of entrainment.

  7. Navigation by environmental geometry: the use of zebrafish as a model.

    Science.gov (United States)

    Lee, Sang Ah; Vallortigara, Giorgio; Flore, Michele; Spelke, Elizabeth S; Sovrano, Valeria A

    2013-10-01

    Sensitivity to environmental shape in spatial navigation has been found, at both behavioural and neural levels, in virtually every species tested, starting early in development. Moreover, evidence that genetic deletions can cause selective deficits in such navigation behaviours suggests a genetic basis to navigation by environmental geometry. Nevertheless, the geometric computations underlying navigation have not been specified in any species. The present study teases apart the geometric components within the traditionally used rectangular enclosure and finds that zebrafish selectively represent distance and directional relationships between extended boundary surfaces. Similar behavioural results in geometric navigation tasks with human children provide prima facie evidence for similar underlying cognitive computations and open new doors for probing the genetic foundations that give rise to these computations.

  8. The role of zebrafish (Danio rerio in dissecting the genetics and neural circuits of executive function

    Directory of Open Access Journals (Sweden)

    Matthew O Parker

    2013-04-01

    Full Text Available Zebrafish have great potential to contribute to our understanding of behavioural genetics and thus to contribute to our understanding of the aetiology of psychiatric disease. However, progress is dependent upon the rate at which behavioural assays addressing complex behavioural phenotypes are designed, reported and validated. Here we critically review existing behavioural assays with particular focus on the use of adult zebrafish to explore executive processes and phenotypes associated with human psychiatric disease. We outline the case for using zebrafish as models to study impulse control and attention, discussing the validity of applying extant rodent assays to zebrafish and evidence for the conservation of relevant neural circuits.

  9. Time-lapse imaging of neural development: zebrafish lead the way into the fourth dimension.

    Science.gov (United States)

    Rieger, Sandra; Wang, Fang; Sagasti, Alvaro

    2011-07-01

    Time-lapse imaging is often the only way to appreciate fully the many dynamic cell movements critical to neural development. Zebrafish possess many advantages that make them the best vertebrate model organism for live imaging of dynamic development events. This review will discuss technical considerations of time-lapse imaging experiments in zebrafish, describe selected examples of imaging studies in zebrafish that revealed new features or principles of neural development, and consider the promise and challenges of future time-lapse studies of neural development in zebrafish embryos and adults. Copyright © 2011 Wiley-Liss, Inc.

  10. Quantification of birefringence readily measures the level of muscle damage in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joachim, E-mail: Joachim.Berger@Monash.edu [Australian Regenerative Medicine Institute, EMBL Australia, Monash University, Clayton (Australia); Sztal, Tamar; Currie, Peter D. [Australian Regenerative Medicine Institute, EMBL Australia, Monash University, Clayton (Australia)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Report of an unbiased quantification of the birefringence of muscle of fish larvae. Black-Right-Pointing-Pointer Quantification method readily identifies level of overall muscle damage. Black-Right-Pointing-Pointer Compare zebrafish muscle mutants for level of phenotype severity. Black-Right-Pointing-Pointer Proposed tool to survey treatments that aim to ameliorate muscular dystrophy. -- Abstract: Muscular dystrophies are a group of genetic disorders that progressively weaken and degenerate muscle. Many zebrafish models for human muscular dystrophies have been generated and analysed, including dystrophin-deficient zebrafish mutants dmd that model Duchenne Muscular Dystrophy. Under polarised light the zebrafish muscle can be detected as a bright area in an otherwise dark background. This light effect, called birefringence, results from the diffraction of polarised light through the pseudo-crystalline array of the muscle sarcomeres. Muscle damage, as seen in zebrafish models for muscular dystrophies, can readily be detected by a reduction in the birefringence. Therefore, birefringence is a very sensitive indicator of overall muscle integrity within larval zebrafish. Unbiased documentation of the birefringence followed by densitometric measurement enables the quantification of the birefringence of zebrafish larvae. Thereby, the overall level of muscle integrity can be detected, allowing the identification and categorisation of zebrafish muscle mutants. In addition, we propose that the establish protocol can be used to analyse treatments aimed at ameliorating dystrophic zebrafish models.

  11. Non-invasive electrocardiogram detection of in vivo zebrafish embryos using electric potential sensors

    Science.gov (United States)

    Rendon-Morales, E.; Prance, R. J.; Prance, H.; Aviles-Espinosa, R.

    2015-11-01

    In this letter, we report the continuous detection of the cardiac electrical activity in embryonic zebrafish using a non-invasive approach. We present a portable and cost-effective platform based on the electric potential sensing technology, to monitor in vivo electrocardiogram activity from the zebrafish heart. This proof of principle demonstration shows how electrocardiogram measurements from the embryonic zebrafish may become accessible by using electric field detection. We present preliminary results using the prototype, which enables the acquisition of electrophysiological signals from in vivo 3 and 5 days-post-fertilization zebrafish embryos. The recorded waveforms show electrocardiogram traces including detailed features such as QRS complex, P and T waves.

  12. Quantification of birefringence readily measures the level of muscle damage in zebrafish

    International Nuclear Information System (INIS)

    Berger, Joachim; Sztal, Tamar; Currie, Peter D.

    2012-01-01

    Highlights: ► Report of an unbiased quantification of the birefringence of muscle of fish larvae. ► Quantification method readily identifies level of overall muscle damage. ► Compare zebrafish muscle mutants for level of phenotype severity. ► Proposed tool to survey treatments that aim to ameliorate muscular dystrophy. -- Abstract: Muscular dystrophies are a group of genetic disorders that progressively weaken and degenerate muscle. Many zebrafish models for human muscular dystrophies have been generated and analysed, including dystrophin-deficient zebrafish mutants dmd that model Duchenne Muscular Dystrophy. Under polarised light the zebrafish muscle can be detected as a bright area in an otherwise dark background. This light effect, called birefringence, results from the diffraction of polarised light through the pseudo-crystalline array of the muscle sarcomeres. Muscle damage, as seen in zebrafish models for muscular dystrophies, can readily be detected by a reduction in the birefringence. Therefore, birefringence is a very sensitive indicator of overall muscle integrity within larval zebrafish. Unbiased documentation of the birefringence followed by densitometric measurement enables the quantification of the birefringence of zebrafish larvae. Thereby, the overall level of muscle integrity can be detected, allowing the identification and categorisation of zebrafish muscle mutants. In addition, we propose that the establish protocol can be used to analyse treatments aimed at ameliorating dystrophic zebrafish models.

  13. Zebrafish CaV2.1 Calcium Channels Are Tailored for Fast Synchronous Neuromuscular Transmission

    Science.gov (United States)

    Naranjo, David; Wen, Hua; Brehm, Paul

    2015-01-01

    The CaV2.2 (N-type) and CaV2.1 (P/Q-type) voltage-dependent calcium channels are prevalent throughout the nervous system where they mediate synaptic transmission, but the basis for the selective presence at individual synapses still remains an open question. The CaV2.1 channels have been proposed to respond more effectively to brief action potentials (APs), an idea supported by computational modeling. However, the side-by-side comparison of CaV2.1 and CaV2.2 kinetics in intact neurons failed to reveal differences. As an alternative means for direct functional comparison we expressed zebrafish CaV2.1 and CaV2.2 α-subunits, along with their accessory subunits, in HEK293 cells. HEK cells lack calcium currents, thereby circumventing the need for pharmacological inhibition of mixed calcium channel isoforms present in neurons. HEK cells also have a simplified morphology compared to neurons, which improves voltage control. Our measurements revealed faster kinetics and shallower voltage-dependence of activation and deactivation for CaV2.1. Additionally, recordings of calcium current in response to a command waveform based on the motorneuron AP show, directly, more effective activation of CaV2.1. Analysis of calcium currents associated with the AP waveform indicate an approximately fourfold greater open probability (PO) for CaV2.1. The efficient activation of CaV2.1 channels during APs may contribute to the highly reliable transmission at zebrafish neuromuscular junctions. PMID:25650925

  14. Priming of innate antimycobacterial immunity by heat-killed Listeria monocytogenes induces sterilizing response in the adult zebrafish tuberculosis model

    Directory of Open Access Journals (Sweden)

    Hanna Luukinen

    2018-01-01

    Full Text Available Mycobacterium tuberculosis remains one of the most problematic infectious agents, owing to its highly developed mechanisms to evade host immune responses combined with the increasing emergence of antibiotic resistance. Host-directed therapies aiming to optimize immune responses to improve bacterial eradication or to limit excessive inflammation are a new strategy for the treatment of tuberculosis. In this study, we have established a zebrafish-Mycobacterium marinum natural host-pathogen model system to study induced protective immune responses in mycobacterial infection. We show that priming adult zebrafish with heat-killed Listeria monocytogenes (HKLm at 1 day prior to M. marinum infection leads to significantly decreased mycobacterial loads in the infected zebrafish. Using rag1−/− fish, we show that the protective immunity conferred by HKLm priming can be induced through innate immunity alone. At 24 h post-infection, HKLm priming leads to a significant increase in the expression levels of macrophage-expressed gene 1 (mpeg1, tumor necrosis factor α (tnfa and nitric oxide synthase 2b (nos2b, whereas superoxide dismutase 2 (sod2 expression is downregulated, implying that HKLm priming increases the number of macrophages and boosts intracellular killing mechanisms. The protective effects of HKLm are abolished when the injected material is pretreated with nucleases or proteinase K. Importantly, HKLm priming significantly increases the frequency of clearance of M. marinum infection by evoking sterilizing immunity (25 vs 3.7%, P=0.0021. In this study, immune priming is successfully used to induce sterilizing immunity against mycobacterial infection. This model provides a promising new platform for elucidating the mechanisms underlying sterilizing immunity and to develop host-directed treatment or prevention strategies against tuberculosis. This article has an associated First Person interview with the first author of the paper.

  15. Effects of phytosterols on zebrafish reproduction in multigeneration test

    International Nuclear Information System (INIS)

    Nakari, Tarja; Erkomaa, Kirsti

    2003-01-01

    A multigeneration test is used to show disruption of the reproductive system by phytosterols. - Zebrafish from mixed sex populations were exposed continuously across three generations to two phytosterol preparations both containing β-sitosterol. The phytosterols were isolated from wood and soy beans. Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures. Both sterol preparations caused vitellogenin induction in the exposed fish. The wood sterol changed the sex ratio of the exposed fish. In generation F1, the predominant sex was male, and in generation F2 it was female. The soy sterol in the used test concentration was lethal to the exposed fish in generation F1. This multigeneration test evidenced that phytosterols containing β-sitosterol disrupt the reproduction system of zebrafish by changing the sex ratios and by inducing the vitellogenin production in the exposed fish

  16. Effects of phytosterols on zebrafish reproduction in multigeneration test

    Energy Technology Data Exchange (ETDEWEB)

    Nakari, Tarja; Erkomaa, Kirsti

    2003-05-01

    A multigeneration test is used to show disruption of the reproductive system by phytosterols. - Zebrafish from mixed sex populations were exposed continuously across three generations to two phytosterol preparations both containing {beta}-sitosterol. The phytosterols were isolated from wood and soy beans. Blood vitellogenin levels and sex ratio changes were used as intermediate indicators of the reproduction failures. Both sterol preparations caused vitellogenin induction in the exposed fish. The wood sterol changed the sex ratio of the exposed fish. In generation F1, the predominant sex was male, and in generation F2 it was female. The soy sterol in the used test concentration was lethal to the exposed fish in generation F1. This multigeneration test evidenced that phytosterols containing {beta}-sitosterol disrupt the reproduction system of zebrafish by changing the sex ratios and by inducing the vitellogenin production in the exposed fish.

  17. Small molecule screening identifies targetable zebrafish pigmentation pathways

    DEFF Research Database (Denmark)

    Colanesi, Sarah; Taylor, Kerrie L; Temperley, Nicholas D

    2012-01-01

    Small molecules complement genetic mutants and can be used to probe pigment cell biology by inhibiting specific proteins or pathways. Here, we present the results of a screen of active compounds for those that affect the processes of melanocyte and iridophore development in zebrafish and investig......Small molecules complement genetic mutants and can be used to probe pigment cell biology by inhibiting specific proteins or pathways. Here, we present the results of a screen of active compounds for those that affect the processes of melanocyte and iridophore development in zebrafish...... and investigate the effects of a few of these compounds in further detail. We identified and confirmed 57 compounds that altered pigment cell patterning, number, survival, or differentiation. Additional tissue targets and toxicity of small molecules are also discussed. Given that the majority of cell types...

  18. Hypoxia-induced metastasis model in embryonic zebrafish

    DEFF Research Database (Denmark)

    Rouhi, Pegah; Jensen, Lasse D.; Cao, Ziquan

    2010-01-01

    Hypoxia facilitates tumor invasion and metastasis by promoting neovascularization and co-option of tumor cells in the peritumoral vasculature, leading to dissemination of tumor cells into the circulation. However, until recently, animal models and imaging technology did not enable monitoring...... of the early events of tumor cell invasion and dissemination in living animals. We recently developed a zebrafish metastasis model to dissect the detailed events of hypoxia-induced tumor cell invasion and metastasis in association with angiogenesis at the single-cell level. In this model, fluorescent Di......I-labeled human or mouse tumor cells are implanted into the perivitelline cavity of 48-h-old zebrafish embryos, which are subsequently placed in hypoxic water for 3 d. Tumor cell invasion, metastasis and pathological angiogenesis are detected under fluorescent microscopy in the living fish. The average...

  19. Bioluminescence Monitoring of Neuronal Activity in Freely Moving Zebrafish Larvae

    Science.gov (United States)

    Knafo, Steven; Prendergast, Andrew; Thouvenin, Olivier; Figueiredo, Sophie Nunes; Wyart, Claire

    2017-01-01

    The proof of concept for bioluminescence monitoring of neural activity in zebrafish with the genetically encoded calcium indicator GFP-aequorin has been previously described (Naumann et al., 2010) but challenges remain. First, bioluminescence signals originating from a single muscle fiber can constitute a major pitfall. Second, bioluminescence signals emanating from neurons only are very small. To improve signals while verifying specificity, we provide an optimized 4 steps protocol achieving: 1) selective expression of a zebrafish codon-optimized GFP-aequorin, 2) efficient soaking of larvae in GFP-aequorin substrate coelenterazine, 3) bioluminescence monitoring of neural activity from motor neurons in free-tailed moving animals performing acoustic escapes and 4) verification of the absence of muscle expression using immunohistochemistry. PMID:29130058

  20. Optogenetics: a new enlightenment age for zebrafish neurobiology.

    Science.gov (United States)

    Del Bene, Filippo; Wyart, Claire

    2012-03-01

    Zebrafish became a model of choice for neurobiology because of the transparency of its brain and because of its amenability to genetic manipulation. In particular, at early stages of development the intact larva is an ideal system to apply optical techniques for deep imaging in the nervous system, as well as genetically encoded tools for targeting subsets of neurons and monitoring and manipulating their activity. For these applications,new genetically encoded optical tools, fluorescent sensors, and light-gated channels have been generated,creating the field of "optogenetics." It is now possible to monitor and control neuronal activity with minimal perturbation and unprecedented spatio-temporal resolution.We describe here the main achievements that have occurred in the last decade in imaging and manipulating neuronal activity in intact zebrafish larvae. We provide also examples of functional dissection of neuronal circuits achieved with the applications of these techniques in the visual and locomotor systems.

  1. Nested Expression Domains for Odorant Receptors in Zebrafish Olfactory Epithelium

    Science.gov (United States)

    Weth, Franco; Nadler, Walter; Korsching, Sigrun

    1996-11-01

    The mapping of high-dimensional olfactory stimuli onto the two-dimensional surface of the nasal sensory epithelium constitutes the first step in the neuronal encoding of olfactory input. We have used zebrafish as a model system to analyze the spatial distribution of odorant receptor molecules in the olfactory epithelium by quantitative in situ hybridization. To this end, we have cloned 10 very divergent zebrafish odorant receptor molecules by PCR. Individual genes are expressed in sparse olfactory receptor neurons. Analysis of the position of labeled cells in a simplified coordinate system revealed three concentric, albeit overlapping, expression domains for the four odorant receptors analyzed in detail. Such regionalized expression should result in a corresponding segregation of functional response properties. This might represent the first step of spatial encoding of olfactory input or be essential for the development of the olfactory system.

  2. Overexpression of Akt1 enhances adipogenesis and leads to lipoma formation in zebrafish.

    Directory of Open Access Journals (Sweden)

    Che-Yu Chu

    Full Text Available BACKGROUND: Obesity is a complex, multifactorial disorder influenced by the interaction of genetic, epigenetic, and environmental factors. Obesity increases the risk of contracting many chronic diseases or metabolic syndrome. Researchers have established several mammalian models of obesity to study its underlying mechanism. However, a lower vertebrate model for conveniently performing drug screening against obesity remains elusive. The specific aim of this study was to create a zebrafish obesity model by over expressing the insulin signaling hub of the Akt1 gene. METHODOLOGY/PRINCIPAL FINDINGS: Skin oncogenic transformation screening shows that a stable zebrafish transgenic of Tg(krt4Hsa.myrAkt1(cy18 displays severely obese phenotypes at the adult stage. In Tg(krt4:Hsa.myrAkt1(cy18, the expression of exogenous human constitutively active Akt1 (myrAkt1 can activate endogenous downstream targets of mTOR, GSK-3α/β, and 70S6K. During the embryonic to larval transitory phase, the specific over expression of myrAkt1 in skin can promote hypertrophic and hyperplastic growth. From 21 hour post-fertilization (hpf onwards, myrAkt1 transgene was ectopically expressed in several mesenchymal derived tissues. This may be the result of the integration position effect. Tg(krt4:Hsa.myrAkt1(cy18 caused a rapid increase of body weight, hyperplastic growth of adipocytes, abnormal accumulation of fat tissues, and blood glucose intolerance at the adult stage. Real-time RT-PCR analysis showed the majority of key genes on regulating adipogenesis, adipocytokine, and inflammation are highly upregulated in Tg(krt4:Hsa.myrAkt1(cy18. In contrast, the myogenesis- and skeletogenesis-related gene transcripts are significantly downregulated in Tg(krt4:Hsa.myrAkt1(cy18, suggesting that excess adipocyte differentiation occurs at the expense of other mesenchymal derived tissues. CONCLUSION/SIGNIFICANCE: Collectively, the findings of this study provide direct evidence that Akt1

  3. Generation of FGF reporter transgenic zebrafish and their utility in chemical screens

    Directory of Open Access Journals (Sweden)

    Tsang Michael

    2007-06-01

    transgenic reporter zebrafish lines has allowed direct visualization of FGF signalling within the developing embryo. These FGF reporter transgenic lines provide a tool to screen for specific compounds that can distinguish between two conserved members of the RTK family.

  4. Short-term memory in zebrafish (Danio rerio).

    Science.gov (United States)

    Jia, Jason; Fernandes, Yohaan; Gerlai, Robert

    2014-08-15

    Learning and memory represent perhaps the most complex behavioral phenomena. Although their underlying mechanisms have been extensively analyzed, only a fraction of the potential molecular components have been identified. The zebrafish has been proposed as a screening tool with which mechanisms of complex brain functions may be systematically uncovered. However, as a relative newcomer in behavioral neuroscience, the zebrafish has not been well characterized for its cognitive and mnemonic features, thus learning and/or memory screens with adults have not been feasible. Here we study short-term memory of adult zebrafish. We show animated images of conspecifics (the stimulus) to the experimental subject during 1 min intervals on ten occasions separated by different (2, 4, 8 or 16 min long) inter-stimulus intervals (ISI), a between subject experimental design. We quantify the distance of the subject from the image presentation screen during each stimulus presentation interval, during each of the 1-min post-stimulus intervals immediately following the stimulus presentations and during each of the 1-min intervals furthest away from the last stimulus presentation interval and just before the next interval (pre-stimulus interval), respectively. Our results demonstrate significant retention of short-term memory even in the longest ISI group but suggest no acquisition of reference memory. Because in the employed paradigm both stimulus presentation and behavioral response quantification is computer automated, we argue that high-throughput screening for drugs or mutations that alter short-term memory performance of adult zebrafish is now becoming feasible. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. In Vivo Cardiotoxicity Induced by Sodium Aescinate in Zebrafish Larvae

    Directory of Open Access Journals (Sweden)

    Jinfeng Liang

    2016-02-01

    Full Text Available Sodium aescinate (SA is a widely-applied triterpene saponin product derived from horse chestnut seeds, possessing vasoactive and organ-protective activities with oral or injection administration in the clinic. To date, no toxicity or adverse events in SA have been reported, by using routine models (in vivo or in vitro, which are insufficient to predict all aspects of its pharmacological and toxicological actions. In this study, taking advantage of transparent zebrafish larvae (Danio rerio, we evaluated cardiovascular toxicity of SA at doses of 1/10 MNLC, 1/3 MNLC, MNLC and LC10 by yolk sac microinjection. The qualitative and quantitative cardiotoxicity in zebrafish was assessed at 48 h post-SA treatment, using specific phenotypic endpoints: heart rate, heart rhythm, heart malformation, pericardial edema, circulation abnormalities, thrombosis and hemorrhage. The results showed that SA at 1/10 MNLC and above doses could induce obvious cardiac and pericardial malformations, whilst 1/3 MNLC and above doses could induce significant cardiac malfunctions (heart rate and circulation decrease/absence, as compared to untreated or vehicle-treated control groups. Such cardiotoxic manifestations occurred in more than 50% to 100% of all zebrafish treated with SA at MNLC and LC10. Our findings have uncovered the potential cardiotoxicity of SA for the first time, suggesting more attention to the risk of its clinical application. Such a time- and cost-saving zebrafish cardiotoxicity assay is very valid and reliable for rapid prediction of compound toxicity during drug research and development.

  6. Developmental toxicity of low generation PAMAM dendrimers in zebrafish

    International Nuclear Information System (INIS)

    King Heiden, Tisha C.; Dengler, Emelyne; Kao, Weiyuan John; Heideman, Warren; Peterson, Richard E.

    2007-01-01

    Biological molecules and intracellular structures operate at the nanoscale; therefore, development of nanomedicines shows great promise for the treatment of disease by using targeted drug delivery and gene therapies. PAMAM dendrimers, which are highly branched polymers with low polydispersity and high functionality, provide an ideal architecture for construction of effective drug carriers, gene transfer devices and imaging of biological systems. For example, dendrimers bioconjugated with selective ligands such as Arg-Gly-Asp (RGD) would theoretically target cells that contain integrin receptors and show potential for use as drug delivery devices. While RGD-conjugated dendrimers are generally considered not to be cytotoxic, there currently exists little information on the risks that such materials pose to human health. In an effort to compliment and extend the knowledge gleaned from cell culture assays, we have used the zebrafish embryo as a rapid, medium throughput, cost-effective whole-animal model to provide a more comprehensive and predictive developmental toxicity screen for nanomaterials such as PAMAM dendrimers. Using the zebrafish embryo, we have assessed the developmental toxicity of low generation (G3.5 and G4) PAMAM dendrimers, as well as RGD-conjugated forms for comparison. Our results demonstrate that G4 dendrimers, which have amino functional groups, are toxic and attenuate growth and development of zebrafish embryos at sublethal concentrations; however, G3.5 dendrimers, with carboxylic acid terminal functional groups, are not toxic to zebrafish embryos. Furthermore, RGD-conjugated G4 dendrimers are less potent in causing embryo toxicity than G4 dendrimers. RGD-conjugated G3.5 dendrimers do not elicit toxicity at the highest concentrations tested and warrant further study for use as a drug delivery device

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

    Directory of Open Access Journals (Sweden)

    Cansu Akbulut

    2013-01-01

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

  8. Clonal analysis of hematopoietic progenitor cells in the zebrafish

    Czech Academy of Sciences Publication Activity Database

    Stachura, D.L.; Svoboda, Ondřej; Lau, R.P.; Balla, K.M.; Zon, L.I.; Bartůněk, Petr; Traver, D.

    2011-01-01

    Roč. 118, č. 5 (2011), s. 1274-1282 ISSN 0006-4971 R&D Projects: GA ČR GA310/08/0878; GA ČR GAP305/10/0953 Institutional research plan: CEZ:AV0Z50520514 Keywords : zebrafish * in vitro culture * hematopoiesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.898, year: 2011

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-15

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

  10. Neurobehavioral impairments caused by developmental imidacloprid exposure in zebrafish.

    Science.gov (United States)

    Crosby, Emily B; Bailey, Jordan M; Oliveri, Anthony N; Levin, Edward D

    2015-01-01

    Neonicotinoid insecticides are becoming more widely applied as organophosphate (OP) insecticides are decreasing in use. Because of their relative specificity to insect nicotinic receptors, they are thought to have reduced risk of neurotoxicity in vertebrates. However, there is scant published literature concerning the neurobehavioral effects of developmental exposure of vertebrates to neonicotinoids. Using zebrafish, we investigated the neurobehavioral effects of developmental exposure to imidacloprid, a prototypic neonicotinoid pesticide. Nicotine was also administered for comparison. Zebrafish were exposed via immersion in aqueous solutions containing 45 μM or 60 μM of imidacloprid or nicotine (or vehicle control) from 4h to 5d post fertilization. The functional effects of developmental exposure to both imidacloprid and nicotine were assessed in larvae using an activity assay and during adolescence and adulthood using a battery of neurobehavioral assays, including assessment of sensorimotor response and habituation in a tactile startle test, novel tank swimming, and shoaling behavior. In larvae, developmental imidacloprid exposure at both doses significantly decreased swimming activity. The 5D strains of zebrafish were more sensitive to both nicotine and imidacloprid than the AB* strain. In adolescent and adult fish, developmental exposure to imidacloprid significantly decreased novel tank exploration and increased sensorimotor response to startle stimuli. While nicotine did not affect novel tank swimming, it increased sensorimotor response to startle stimuli at the low dose. No effects of either compound were found on shoaling behavior or habituation to a startling stimulus. Early developmental exposure to imidacloprid has both early-life and persisting effects on neurobehavioral function in zebrafish. Its developmental neurotoxicity should be further investigated. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. SENSORY HAIR CELL REGENERATION IN THE ZEBRAFISH LATERAL LINE

    OpenAIRE

    Lush, Mark E.; Piotrowski, Tatjana

    2014-01-01

    Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing ther...

  12. Zebrafish in Brazilian Science: Scientific Production, Impact, and Collaboration.

    Science.gov (United States)

    Gheno, Ediane Maria; Rosemberg, Denis Broock; Souza, Diogo Onofre; Calabró, Luciana

    2016-06-01

    By means of scientometric indicators, this study investigated the characteristics of scientific production and research collaboration involving zebrafish (Danio rerio) in Brazilian Science indexed by the Web of Science (WoS). Citation data were collected from the WoS and data regarding Impact Factor (IF) were gathered from journals in the Journal Citation Reports. Collaboration was evaluated according to coauthorship data, creating representative nets with VOSviewer. Zebrafish has attained remarkable importance as an experimental model organism in recent years and an increase in scientific production with zebrafish is observed in Brazil and around the world. The citation impact of the worldwide scientific production is superior when compared to the Brazilian scientific production. However, the citation impact of the Brazilian scientific production is consistently increasing. Brazil does not follow the international trends with regard to publication research fields. The state of Rio Grande do Sul has the greatest number of articles and the institution with the largest number of publications is Pontifícia Universidade Católica do Rio Grande do Sul. Journals' average IF is higher in Brazilian publications with international coauthorship, and around 90% of articles are collaborative. The Brazilian institutions presenting the greatest number of collaborations are Pontifícia Universidade Católica do Rio Grande do Sul, Universidade Federal do Rio Grande do Sul, Fundação Universidade Federal de Rio Grande, and Universidade de São Paulo. These data indicate that Brazilian research using zebrafish presents a growth in terms of number of publications, citation impact, and collaborative work.

  13. Ex vivo tools for the clonal analysis of zebrafish hematopoiesis

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Ondřej; Stachura, D.L.; Machoňová, Olga; Zon, L.I.; Traver, D.; Bartůněk, Petr

    2016-01-01

    Roč. 11, č. 5 (2016), s. 1007-1020 ISSN 1754-2189 R&D Projects: GA MŠk LO1419; GA ČR GA16-21024S Institutional support: RVO:68378050 Keywords : stem-cells * in-vitro * vertebrate hematopoiesis * transgenic zebrafish * progenitor cells * danio-rerio * fish * thrombopoietin * identification * specification Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.032, year: 2016

  14. Simple, economical heat-shock devices for zebrafish housing racks.

    Science.gov (United States)

    Duszynski, Robert J; Topczewski, Jacek; LeClair, Elizabeth E

    2011-12-01

    One reason for the popularity of the zebrafish (Danio rerio) as a model vertebrate is the ability to manipulate gene expression in this organism. A common method is to induce gene expression transiently under control of a heat-shock promoter (e.g., hsp70l). By making simple mechanical adjustments to small aquarium heaters (25-50W), we were able to produce consistent and reliable heat-shock conditions within a conventional zebrafish housing system. Up to two heat-shock intervals per day (>37°C) could be maintained under conditions of continuous flow (5-25 mL/min). Temperature logging every 30 s indicated rapid warm up times, consistent heat-shock lengths, and accurate and precise peak water temperatures (mean±SD=38°C±0.2°C). The biological effects of these heat-shock treatments were confirmed by observing inducible expression of enhanced green fluorescent protein (EGFP) and inhibition of caudal fin regeneration in a transgenic fish line expressing a dominant negative fibroblast growth factor receptor (Tg(hsp70l:dnfgfr1-EGFP)(pd1)). These devices are inexpensive, easily modified, and can be calibrated to accommodate a variety of experimental designs. After setup on a programmable timer, the heaters require no intervention to produce consistent daily heat shocks, and all other standard care protocols can be followed in the fish facility. The simplicity and stability of these devices make them suitable for long-term heat shocks at any stage of the zebrafish lifecycle (>7 days postfertilization), and useful for both laboratory and classroom experiments on transgenic zebrafish.

  15. Developmental neurotoxicity of pyrethroid insecticides in zebrafish embryos.

    Science.gov (United States)

    DeMicco, Amy; Cooper, Keith R; Richardson, Jason R; White, Lori A

    2010-01-01

    Pyrethroid insecticides are one of the most commonly used residential and agricultural insecticides. Based on the increased use of pyrethroids and recent studies showing that pregnant women and children are exposed to pyrethroids, there are concerns over the potential for developmental neurotoxicity. However, there have been relatively few studies on the developmental neurotoxicity of pyrethroids. In this study, we sought to investigate the developmental toxicity of six common pyrethroids, three type I compounds (permethrin, resmethrin, and bifenthrin) and three type II compounds (deltamethrin, cypermethrin, and lambda-cyhalothrin), and to determine whether zebrafish embryos may be an appropriate model for studying the developmental neurotoxicity of pyrethroids. Exposure of zebrafish embryos to pyrethroids caused a dose-dependent increase in mortality and pericardial edema, with type II compounds being the most potent. At doses approaching the LC(50), permethrin and deltamethrin caused craniofacial abnormalities. These findings are consistent with mammalian studies demonstrating that pyrethroids are mildly teratogenic at very high doses. However, at lower doses, body axis curvature and spasms were observed, which were reminiscent of the classic syndromes observed with pyrethroid toxicity. Treatment with diazepam ameliorated the spasms, while treatment with the sodium channel antagonist MS-222 ameliorated both spasms and body curvature, suggesting that pyrethroid-induced neurotoxicity is similar in zebrafish and mammals. Taken in concert, these data suggest that zebrafish may be an appropriate alternative model to study the mechanism(s) responsible for the developmental neurotoxicity of pyrethroid insecticides and aid in identification of compounds that should be further tested in mammalian systems.

  16. Role of hepsin in factor VII activation in zebrafish.

    Science.gov (United States)

    Khandekar, Gauri; Jagadeeswaran, Pudur

    2014-01-01

    Factor VII, the initiator of the extrinsic coagulation cascade, circulates in human plasma mainly in its zymogen form, factor VII and in small amounts in its activated form, factor VIIa. However, the mechanism of initial generation of factor VIIa is not known despite intensive research using currently available model systems. Earlier findings suggested serine proteases factor VII activating protease and hepsin play a role in activating factor VII, however, it has remained controversial. In this paper we estimated the levels of factor VIIa and factor VII for the first time in zebrafish adult population and also reevaluated the role of the above two serine proteases in activating factor VII in vivo using zebrafish as a model system. Knockdown of factor VII activating protease and hepsin was performed followed by assaying for their effect on factor VIIa concentration and extrinsic coagulation as measured by the kinetic prothrombin time. Factor VII activating protease knockdown showed no change in kinetic prothrombin time and no effect on factor VIIa levels while hepsin knockdown increased the kinetic prothrombin time and significantly reduced the factor VIIa plasma levels. Our results thus indicate that hepsin plays a physiologically important role in factor VII activation and hemostasis in zebrafish. © 2013.

  17. Vitamin D receptor deficiency impairs inner ear development in zebrafish

    International Nuclear Information System (INIS)

    Kwon, Hye-Joo

    2016-01-01

    The biological actions of vitamin D are largely mediated through binding to the vitamin D receptor (VDR), a member of the nuclear hormone receptor family, which regulates gene expression in a wide variety of tissues and cells. Mutations in VDR gene have been implicated in ear disorders (hearing loss and balance disorder) but the mechanisms are not well established. In this study, to investigate the role of VDR in inner ear development, morpholino-mediated gene knockdown approaches were used in zebrafish model system. Two paralogs for VDR, vdra and vdrb, have been identified in zebrafish. Knockdown of vdra had no effect on ear development, whereas knockdown of vdrb displayed morphological ear defects including smaller otic vesicles with malformed semicircular canals and abnormal otoliths. Loss-of-vdrb resulted in down-regulation of pre-otic markers, pax8 and pax2a, indicating impairment of otic induction. Furthermore, zebrafish embryos lacking vdrb produced fewer sensory hair cells in the ears and showed disruption of balance and motor coordination. These data reveal that VDR signaling plays an important role in ear development. - Highlights: • VDR signaling is involved in ear development. • Knockdown of vdrb causes inner ear malformations during embryogenesis. • Knockdown of vdrb affects otic placode induction. • Knockdown of vdrb reduces the number of sensory hair cells in the inner ear. • Knockdown of vdrb disrupts balance and motor coordination.

  18. Deletion of Pr130 Interrupts Cardiac Development in Zebrafish

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2016-11-01

    Full Text Available Protein phosphatase 2 regulatory subunit B, alpha (PPP2R3A, a regulatory subunit of protein phosphatase 2A (PP2A, is a major serine/threonine phosphatase that regulates crucial function in development and growth. Previous research has implied that PPP2R3A was involved in heart failure, and PR130, the largest transcription of PPP2R3A, functioning in the calcium release of sarcoplasmic reticulum (SR, plays an important role in the excitation-contraction (EC coupling. To obtain a better understanding of PR130 functions in myocardium and cardiac development, two pr130-deletion zebrafish lines were generated using clustered regularly interspaced short palindromic repeats (CRISPR/CRISPR-associated proteins (Cas system. Pr130-knockout zebrafish exhibited cardiac looping defects and decreased cardiac function (decreased fractional area and fractional shortening. Hematoxylin and eosin (H&E staining demonstrated reduced cardiomyocytes. Subsequent transmission electron microscopy revealed that the bright and dark bands were narrowed and blurred, the Z- and M-lines were fogged, and the gaps between longitudinal myocardial fibers were increased. Additionally, increased apoptosis was observed in cardiomyocyte in pr130-knockout zebrafish compared to wild-type (WT. Taken together, our results suggest that pr130 is required for normal myocardium formation and efficient cardiac contractile function.

  19. Heritable and lineage-specific gene knockdown in zebrafish embryo.

    Directory of Open Access Journals (Sweden)

    Mei Dong

    Full Text Available BACKGROUND: Reduced expression of developmentally important genes and tumor suppressors due to haploinsufficiency or epigenetic suppression has been shown to contribute to the pathogenesis of various malignancies. However, methodology that allows spatio-temporally knockdown of gene expression in various model organisms such as zebrafish has not been well established, which largely limits the potential of zebrafish as a vertebrate model of human malignant disorders. PRINCIPAL FINDING: Here, we report that multiple copies of small hairpin RNA (shRNA are expressed from a single transcript that mimics the natural microRNA-30e precursor (mir-shRNA. The mir-shRNA, when microinjected into zebrafish embryos, induced an efficient knockdown of two developmentally essential genes chordin and alpha-catenin in a dose-controllable fashion. Furthermore, we designed a novel cassette vector to simultaneously express an intronic mir-shRNA and a chimeric red fluorescent protein driven by lineage-specific promoter, which efficiently reduced the expression of a chromosomally integrated reporter gene and an endogenously expressed gata-1 gene in the developing erythroid progenitors and hemangioblasts, respectively. SIGNIFICANCE: This methodology provides an invaluable tool to knockdown developmental important genes in a tissue-specific manner or to establish animal models, in which the gene dosage is critically important in the pathogenesis of human disorders. The strategy should be also applicable to other model organisms.

  20. Mutations in LRRC50 predispose zebrafish and humans to seminomas.

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    Sander G Basten

    2013-04-01

    Full Text Available Seminoma is a subclass of human testicular germ cell tumors (TGCT, the most frequently observed cancer in young men with a rising incidence. Here we describe the identification of a novel gene predisposing specifically to seminoma formation in a vertebrate model organism. Zebrafish carrying a heterozygous nonsense mutation in Leucine-Rich Repeat Containing protein 50 (lrrc50 also called dnaaf1, associated previously with ciliary function, are found to be highly susceptible to the formation of seminomas. Genotyping of these zebrafish tumors shows loss of heterozygosity (LOH of the wild-type lrrc50 allele in 44.4% of tumor samples, correlating with tumor progression. In humans we identified heterozygous germline LRRC50 mutations in two different pedigrees with a family history of seminomas, resulting in a nonsense Arg488* change and a missense Thr590Met change, which show reduced expression of the wild-type allele in seminomas. Zebrafish in vivo complementation studies indicate the Thr590Met to be a loss-of-function mutation. Moreover, we show that a pathogenic Gln307Glu change is significantly enriched in individuals with seminoma tumors (13% of our cohort. Together, our study introduces an animal model for seminoma and suggests LRRC50 to be a novel tumor suppressor implicated in human seminoma pathogenesis.

  1. Quantification of vestibular-induced eye movements in zebrafish larvae

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    Mo Weike

    2010-09-01

    Full Text Available Abstract Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR, a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf, which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  3. Analyzing the structure and function of neuronal circuits in zebrafish

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    Rainer eFriedrich

    2013-04-01

    Full Text Available The clever choice of animal models has been instrumental for many breakthrough discoveries in life sciences. One of the outstanding challenges in neuroscience is the in-depth analysis of neuronal circuits to understand how interactions between large numbers of neurons give rise to the computational power of the brain. A promising model organism to address this challenge is the zebrafish, not only because it is cheap, transparent and accessible to sophisticated genetic manipulations but also because it offers unique advantages for quantitative analyses of circuit structure and function. One of the most important advantages of zebrafish is its small brain size, both at larval and adult stages. Small brains enable exhaustive measurements of neuronal activity patterns by optical imaging and facilitate large-scale reconstructions of wiring diagrams by electron microscopic approaches. Such information is important, and probably essential, to obtain mechanistic insights into neuronal computations underlying higher brain functions and dysfunctions. This review provides a brief overview over current methods and motivations for dense reconstructions of neuronal activity and connectivity patterns. It then discusses selective advantages of zebrafish and provides examples how these advantages are exploited to study neuronal computations in the olfactory bulb.

  4. Long-Term Social Recognition Memory in Zebrafish.

    Science.gov (United States)

    Madeira, Natália; Oliveira, Rui F

    2017-08-01

    In species in which individuals live in stable social groups, individual recognition is expected to evolve to allow individuals to remember past interactions with different individuals and adjust future behavior toward them accordingly. Thus, social memory is expected to be a ubiquitous component of social cognition of social species. However, few studies have investigated the occurrence of social memory in non-mammals. Here we evaluated the ability of zebrafish (Danio rerio) to recognize different conspecifics and to retain this information in long lasting (i.e. 24 h) memories. We used a social discrimination paradigm, adapted from mouse studies, in which the focal individual meets two pairs of conspecifics in two consecutive days: one conspecific is the same in both days and the other is different between days 1 and 2. If animals have the ability to discriminate between different conspecifics, it is predicted that they will spend more time exploring the novel than the familiar (i.e. already seen in day 1) conspecific. In this study, zebrafish with access to both olfactory and visual conspecific cues exhibited consistent recognition of a previously encountered (familiar) conspecific after a 24 h delay. This result supports the hypothesis that long-term social memory, previously described in mammals, is also present in zebrafish, hence extending the evidence for the presence of this type of memory to teleost fish.

  5. Modafinil decreases anxiety-like behaviour in zebrafish

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    Adrian Johnson

    2017-02-01

    Full Text Available Modafinil (2-((diphenylmethylsulfinylacetamide, a selective dopamine and norepinephrine transporter inhibitor, is most commonly prescribed for narcolepsy but has gained recent interest for treating a variety of disorders. Zebrafish (Danio rerio are becoming a model of choice for pharmacological and behavioural research. To investigate the behavioural effects of modafinil on anxiety, we administered doses of 0, 2, 20, and 200 mg/L for 30 minutes then tested zebrafish in the novel approach test. In this test, the fish was placed into a circular arena with a novel object in the center and motion-tracking software was used to quantify the time the fish spent in the outer area of the arena (thigmotaxis zone, middle third of the arena (transition zone and center of the arena, as well as total distance traveled, immobility and meandering. Modafinil caused a decrease in time spent in the thigmotaxis zone and increased time spent in the transition zone across all doses. Modafinil did not significantly alter the time spent in the center zone (near the novel object, the distance moved, meandering, or the duration of time spent immobile. We also validated this test as a measure of anxiety with the administration of ethanol (1% which decreased time spent in the thigmotaxis zone and increased time spent in the transition zone. These results suggest that modafinil decreases anxiety-like behaviour in zebrafish.

  6. Triclosan is a Mitochondrial Uncoupler in Live Zebrafish

    Science.gov (United States)

    Shim, Juyoung; Weatherly, Lisa M.; Luc, Richard H.; Dorman, Maxwell T.; Neilson, Andy; Ng, Ryan; Kim, Carol H.; Millard, Paul J.; Gosse, Julie A.

    2016-01-01

    Triclosan (TCS) is a synthetic antimicrobial agent used in many consumer goods at millimolar concentrations. As a result of exposure, TCS has been detected widely in humans. We have recently discovered that TCS is a proton ionophore mitochondrial uncoupler in multiple types of living cells. Here we present novel data indicating that TCS is also a mitochondrial uncoupler in a living organism: 24 hour post fertilization zebrafish embryos. These experiments were conducted using a Seahorse Bioscience XFe 96 Extracellular Flux Analyzer modified for bidirectional temperature control, using the XF96 spheroid plate to position and measure one zebrafish embryo per well. Using this method, following acute exposure to TCS, basal oxygen consumption rate (OCR) increases, without a decrease in survival or heartbeat rate. TCS also decreases ATP-linked respiration and spare respiratory capacity and increases proton leak: all indicators of mitochondrial uncoupling. Our data indicate, that TCS is a mitochondrial uncoupler in vivo, which should be taken into consideration when assessing the toxicity and/or pharmaceutical uses of TCS. This is the first example of usage of a Seahorse Extracellular Flux Analyzer to measure bioenergetic flux of a single zebrafish embryo per well in a 96 well assay format. The method developed in this study provides a high-throughput tool to identify previously-unknown mitochondrial uncouplers in a living organism. PMID:27111768

  7. Hepassocin is required for hepatic outgrowth during zebrafish hepatogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ming [Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072 (China); Beijing Institute of Radiation Medicine, Beijing 100850 (China); Yan, Hui [Beijing Institute of Pharmacology and Toxicology, Beijing 100850 (China); Yin, Rong-Hua [Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key Laboratory of Proteomics, Beijing 100850 (China); Wang, Qiang [Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Zhan, Yi-Qun; Yu, Miao; Ge, Chang-Hui; Li, Chang-Yan; Wang, Xiao-Hui [Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key Laboratory of Proteomics, Beijing 100850 (China); Ge, Zhi-Qiang [Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072 (China); Yang, Xiao-Ming, E-mail: xiaomingyang@sina.com [Tianjin University, Department of Pharmaceutical Engineering, Tianjin 300072 (China); Beijing Institute of Radiation Medicine, Beijing 100850 (China); State Key Laboratory of Proteomics, Beijing 100850 (China)

    2015-07-31

    Background & aims: Hepassocin (HPS) is a hepatotrophic growth factor that specifically stimulates hepatocyte proliferation and promotes liver regeneration after liver damage. In this paper, zebrafish were used to investigate the role of HPS in liver development. Methods and results: During zebrafish development, HPS expression is enriched in liver throughout hepatogenesis. Knockdown of HPS using its specific morpholino leads to a smaller liver phenotype. Further results showed that the HPS knockdown has no effect on the expression of the early endoderm marker gata6 and early hepatic marker hhex. In addition, results showed that the smaller-liver phenotype in HPS morphants was caused by suppression of cell proliferation, not induction of cell apoptosis. Conclusions: Current findings indicated that HPS is essential to the later stages of development in vertebrate liver organogenesis. - Highlights: • HPS is enriched in zebrafish liver and has strong similarities with other species. • Knocking down HPS with MOs results in small liver phenotype. • HPS depletion regulates liver outgrowth but not liver specification and budding. • HPS depletion causes hepatocyte proliferation arrest but not apoptosis induction.

  8. Histological Characterization of the Dicer1 Mutant Zebrafish Retina

    Directory of Open Access Journals (Sweden)

    Saeed Akhtar

    2015-01-01

    Full Text Available DICER1, a multidomain RNase III endoribonuclease, plays a critical role in microRNA (miRNA and RNA-interference (RNAi functional pathways. Loss of Dicer1 affects different developmental processes. Dicer1 is essential for retinal development and maintenance. DICER1 was recently shown to have another function of silencing the toxicity of Alu RNAs in retinal pigment epithelium (RPE cells, which are involved in the pathogenesis of age related macular degeneration. In this study, we characterized a Dicer1 mutant fish line, which carries a nonsense mutation (W1457Ter induced by N-ethyl-N-nitrosourea mutagenesis. Zebrafish DICER1 protein is highly conserved in the evolution. Zebrafish Dicer1 is expressed at the earliest stages of zebrafish development and persists into late developmental stages; it is widely expressed in adult tissues. Homozygous Dicer1 mutant fish (DICER1W1457Ter/W1457Ter have an arrest in early growth with significantly smaller eyes and are dead at 14–18 dpf. Heterozygous Dicer1 mutant fish have similar retinal structure to that of control fish; the retinal pigment epithelium (RPE cells are normal with no sign of degeneration at the age of 20 months.

  9. Sensory hair cell regeneration in the zebrafish lateral line.

    Science.gov (United States)

    Lush, Mark E; Piotrowski, Tatjana

    2014-10-01

    Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing therapies to induce regeneration in mammals. Zebrafish not only possess hair cells in the ear but also in the sensory lateral line system. Hair cells in both organs are functionally analogous to hair cells in the inner ear of mammals. The lateral line is a mechanosensory system found in most aquatic vertebrates that detects water motion and aids in predator avoidance, prey capture, schooling, and mating. Although hair cell regeneration occurs in both the ear and lateral line, most research to date has focused on the lateral line due to its relatively simple structure and accessibility. Here we review the recent discoveries made during the characterization of hair cell regeneration in zebrafish. Copyright © 2014 Wiley Periodicals, Inc.

  10. Effects of piracetam on behavior and memory in adult zebrafish.

    Science.gov (United States)

    Grossman, Leah; Stewart, Adam; Gaikwad, Siddharth; Utterback, Eli; Wu, Nadine; Dileo, John; Frank, Kevin; Hart, Peter; Howard, Harry; Kalueff, Allan V

    2011-04-25

    Piracetam, a derivative of γ-aminobutyric acid, exerts memory-enhancing and mild anxiolytic effects in human and rodent studies. To examine the drug's behavioral profile further, we assessed its effects on behavioral and endocrine (cortisol) responses of adult zebrafish (Danio rerio)--a novel model species rapidly gaining popularity in neurobehavioral research. Overall, acute piracetam did not affect zebrafish novel tank and light-dark box behavior at mild doses (25-400mg/L), but produced nonspecific behavioral inhibition at 700mg/L. No effects on cortisol levels or inter-/intra-session habituation in the novel tank test were observed for acute or chronic mild non-sedative dose of 200mg/L. In contrast, fish exposed to chronic piracetam at this dose performed significantly better in the cued learning plus-maze test. This observation parallels clinical and rodent literature on the behavioral profile of piracetam, supporting the utility of zebrafish paradigms for testing nootropic agents. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Zebrafish neurotransmitter systems as potential pharmacological and toxicological targets.

    Science.gov (United States)

    Rico, E P; Rosemberg, D B; Seibt, K J; Capiotti, K M; Da Silva, R S; Bonan, C D

    2011-01-01

    Recent advances in neurobiology have emphasized the study of brain structure and function and its association with numerous pathological and toxicological events. Neurotransmitters are substances that relay, amplify, and modulate electrical signals between neurons and other cells. Neurotransmitter signaling mediates rapid intercellular communication by interacting with cell surface receptors, activating second messenger systems and regulating the activity of ion channels. Changes in the functional balance of neurotransmitters have been implicated in the failure of central nervous system function. In addition, abnormalities in neurotransmitter production or functioning can be induced by several toxicological compounds, many of which are found in the environment. The zebrafish has been increasingly used as an animal model for biomedical research, primarily due to its genetic tractability and ease of maintenance. These features make this species a versatile tool for pre-clinical drug discovery and toxicological investigations. Here, we present a review regarding the role of different excitatory and inhibitory neurotransmitter systems in zebrafish, such as dopaminergic, serotoninergic, cholinergic, purinergic, histaminergic, nitrergic, glutamatergic, glycinergic, and GABAergic systems, and emphasizing their features as pharmacological and toxicological targets. The increase in the global knowledge of neurotransmitter systems in zebrafish and the elucidation of their pharmacological and toxicological aspects may lead to new strategies and appropriate research priorities to offer insights for biomedical and environmental research. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Hepassocin is required for hepatic outgrowth during zebrafish hepatogenesis

    International Nuclear Information System (INIS)

    Gao, Ming; Yan, Hui; Yin, Rong-Hua; Wang, Qiang; Zhan, Yi-Qun; Yu, Miao; Ge, Chang-Hui; Li, Chang-Yan; Wang, Xiao-Hui; Ge, Zhi-Qiang; Yang, Xiao-Ming

    2015-01-01

    Background & aims: Hepassocin (HPS) is a hepatotrophic growth factor that specifically stimulates hepatocyte proliferation and promotes liver regeneration after liver damage. In this paper, zebrafish were used to investigate the role of HPS in liver development. Methods and results: During zebrafish development, HPS expression is enriched in liver throughout hepatogenesis. Knockdown of HPS using its specific morpholino leads to a smaller liver phenotype. Further results showed that the HPS knockdown has no effect on the expression of the early endoderm marker gata6 and early hepatic marker hhex. In addition, results showed that the smaller-liver phenotype in HPS morphants was caused by suppression of cell proliferation, not induction of cell apoptosis. Conclusions: Current findings indicated that HPS is essential to the later stages of development in vertebrate liver organogenesis. - Highlights: • HPS is enriched in zebrafish liver and has strong similarities with other species. • Knocking down HPS with MOs results in small liver phenotype. • HPS depletion regulates liver outgrowth but not liver specification and budding. • HPS depletion causes hepatocyte proliferation arrest but not apoptosis induction

  13. Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish

    Directory of Open Access Journals (Sweden)

    Wenyan Chen

    2014-07-01

    Full Text Available Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri, larvae and embryos of zebrafish (Danio rerio were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v and 1.95% (v/v respectively, and embryonic development was inhibited at just 1% (v/v. Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR, while the LC50 of larvae was 75.23% (v/v and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent.

  14. Functional and Genetic Analysis of Choroid Plexus Development in Zebrafish

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    Hannah Elizabeth Henson

    2014-11-01

    Full Text Available The choroid plexus, an epithelial-based structure localized in the brain ventricle, is the major component of the blood-cerebrospinal fluid barrier. The choroid plexus produces the cerebrospinal fluid and regulates the components of the cerebrospinal fluid. Abnormal choroid plexus function is associated with neurodegenerative diseases, tumor formation in the choroid plexus epithelium, and hydrocephaly. In this study, we used zebrafish (Danio rerio as a model system to understand the genetic components of choroid plexus development. We generated an enhancer trap line, Et(cp:EGFPsj2, that expresses enhanced green fluorescent protein (EGFP in the choroid plexus epithelium. Using immunohistochemistry and fluorescent tracers, we demonstrated that the zebrafish choroid plexus possesses brain barrier properties such as tight junctions and transporter activity. Thus, we have established zebrafish as a functionally relevant model to study choroid plexus development. Using an unbiased approach, we performed a forward genetic dissection of the choroid plexus to identify genes essential for its formation and function. Using Et(cp:EGFPsj2, we isolated 10 recessive mutant lines with choroid plexus abnormalities, which were grouped into five classes based on GFP intensity, epithelial localization, and overall choroid plexus morphology. We also mapped the mutation for two mutant lines to chromosomes 4 and 21, respectively. The mutants generated in this study can be used to elucidate specific genes and signaling pathways essential for choroid plexus development, function, and/or maintenance and will provide important insights into how these genetic mutations contribute to disease.

  15. Daily shoaling patterns in the zebrafish Danio rerio

    Directory of Open Access Journals (Sweden)

    Timothy PACIOREK, Scott McROBERT

    2013-12-01

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

  16. SENSORY HAIR CELL REGENERATION IN THE ZEBRAFISH LATERAL LINE

    Science.gov (United States)

    Lush, Mark E.; Piotrowski, Tatjana

    2014-01-01

    Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing therapies to induce regeneration in mammals. Zebrafish not only possess hair cells in the ear but also in the sensory lateral line system. Hair cells in both organs are functionally analogous to hair cells in the inner ear of mammals. The lateral line is a mechanosensory system found in most aquatic vertebrates that detects water motion and aids in predator avoidance, prey capture, schooling and mating. Although hair cell regeneration occurs in both the ear and lateral line, most research to date has focused on the lateral line due to its relatively simple structure and accessibility. Here we review the recent discoveries made during the characterization of hair cell regeneration in zebrafish. PMID:25045019

  17. Zebrafish brd2a and brd2b are paralogous members of the bromodomain-ET (BET family of transcriptional coregulators that show structural and expression divergence

    Directory of Open Access Journals (Sweden)

    Bee Katharine J

    2008-04-01

    Full Text Available Abstract Background Brd2 belongs to the bromodomain-extraterminal domain (BET family of transcriptional co-regulators, and functions as a pivotal histone-directed recruitment scaffold in chromatin modification complexes affecting signal-dependent transcription. Brd2 facilitates expression of genes promoting proliferation and is implicated in apoptosis and in egg maturation and meiotic competence in mammals; it is also a susceptibility gene for juvenile myoclonic epilepsy (JME in humans. The brd2 ortholog in Drosophila is a maternal effect, embryonic lethal gene that regulates several homeotic loci, including Ultrabithorax. Despite its importance, there are few systematic studies of Brd2 developmental expression in any organism. To help elucidate both conserved and novel gene functions, we cloned and characterized expression of brd2 cDNAs in zebrafish, a vertebrate system useful for genetic analysis of development and disease, and for study of the evolution of gene families and functional diversity in chordates. Results We identify cDNAs representing two paralogous brd2 loci in zebrafish, brd2a on chromosome 19 and brd2b on chromosome 16. By sequence similarity, syntenic and phylogenetic analyses, we present evidence for structural divergence of brd2 after gene duplication in fishes. brd2 paralogs show potential for modular domain combinations, and exhibit distinct RNA expression patterns throughout development. RNA in situ hybridizations in oocytes and embryos implicate brd2a and brd2b as maternal effect genes involved in egg polarity and egg to embryo transition, and as zygotic genes important for development of the vertebrate nervous system and for morphogenesis and differentiation of the digestive tract. Patterns of brd2 developmental expression in zebrafish are consistent with its proposed role in Homeobox gene regulation. Conclusion Expression profiles of zebrafish brd2 paralogs support a role in vertebrate developmental patterning and

  18. Functional Investigation of a Non-coding Variant Associated with Adolescent Idiopathic Scoliosis in Zebrafish: Elevated Expression of the Ladybird Homeobox Gene Causes Body Axis Deformation.

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    Long Guo

    2016-01-01

    Full Text Available Previously, we identified an adolescent idiopathic scoliosis susceptibility locus near human ladybird homeobox 1 (LBX1 and FLJ41350 by a genome-wide association study. Here, we characterized the associated non-coding variant and investigated the function of these genes. A chromosome conformation capture assay revealed that the genome region with the most significantly associated single nucleotide polymorphism (rs11190870 physically interacted with the promoter region of LBX1-FLJ41350. The promoter in the direction of LBX1, combined with a 590-bp region including rs11190870, had higher transcriptional activity with the risk allele than that with the non-risk allele in HEK 293T cells. The ubiquitous overexpression of human LBX1 or either of the zebrafish lbx genes (lbx1a, lbx1b, and lbx2, but not FLJ41350, in zebrafish embryos caused body curvature followed by death prior to vertebral column formation. Such body axis deformation was not observed in transcription activator-like effector nucleases mediated knockout zebrafish of lbx1b or lbx2. Mosaic expression of lbx1b driven by the GATA2 minimal promoter and the lbx1b enhancer in zebrafish significantly alleviated the embryonic lethal phenotype to allow observation of the later onset of the spinal curvature with or without vertebral malformation. Deformation of the embryonic body axis by lbx1b overexpression was associated with defects in convergent extension, which is a component of the main axis-elongation machinery in gastrulating embryos. In embryos overexpressing lbx1b, wnt5b, a ligand of the non-canonical Wnt/planar cell polarity (PCP pathway, was significantly downregulated. Injection of mRNA for wnt5b or RhoA, a key downstream effector of Wnt/PCP signaling, rescued the defective convergent extension phenotype and attenuated the lbx1b-induced curvature of the body axis. Thus, our study presents a novel pathological feature of LBX1 and its zebrafish homologs in body axis deformation at

  19. Screening estrogenic activities of chemicals or mixtures in vivo using transgenic (cyp19a1b-GFP zebrafish embryos.

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    François Brion

    Full Text Available The tg(cyp19a1b-GFP transgenic zebrafish expresses GFP (green fluorescent protein under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i it is only expressed in radial glial progenitors in the brain of fish and (ii it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture, including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective.

  20. Zebrafish embryos as models for embryotoxic and teratological effects of chemicals.

    NARCIS (Netherlands)

    Yang, Lixin; Ho, Nga Yu; Alshut, Rüdiger; Legradi, J.B.; Weiss, Carsten; Reischl, Markus; Mikut, Ralf; Liebel, Urban; Müller, Ferenc; Strähle, Uwe

    2009-01-01

    The experimental virtues of the zebrafish embryo such as small size, development outside of the mother, cheap maintenance of the adult made the zebrafish an excellent model for phenotypic genetic and more recently also chemical screens. The availability of a genome sequence and several thousand

  1. Effects of copper oxide nanoparticles and copper ions to zebrafish (Danio rerio) cells, embryos and fry

    DEFF Research Database (Denmark)

    Thit, Amalie; Skjolding, Lars Michael; Selck, Henriette

    2017-01-01

    The use of engineered metal nanoparticles (NPs) is continuously increasing and so is the need for information regarding their toxicity. This study compares the toxicity of CuO NPs with ionic Cu in three zebrafish model systems; zebrafish hepatoma cell line (ZFL), fish embryo toxicity test (FET) a...

  2. Zebrafish as a Model System for Investigating the Compensatory Regulation of Ionic Balance during Metabolic Acidosis

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    Lletta Lewis

    2018-04-01

    Full Text Available Zebrafish (Danio rerio have become an important model for integrative physiological research. Zebrafish inhabit a hypo-osmotic environment; to maintain ionic and acid-base homeostasis, they must actively take up ions and secrete acid to the water. The gills in the adult and the skin at larval stage are the primary sites of ionic regulation in zebrafish. The uptake of ions in zebrafish is mediated by specific ion transporting cells termed ionocytes. Similarly, in mammals, ion reabsorption and acid excretion occur in specific cell types in the terminal region of the renal tubules (distal convoluted tubule and collecting duct. Previous studies have suggested that functional regulation of several ion transporters/channels in the zebrafish ionocytes resembles that in the mammalian renal cells. Additionally, several mechanisms involved in regulating the epithelial ion transport during metabolic acidosis are found to be similar between zebrafish and mammals. In this article, we systemically review the similarities and differences in ionic regulation between zebrafish and mammals during metabolic acidosis. We summarize the available information on the regulation of epithelial ion transporters during acidosis, with a focus on epithelial Na+, Cl− and Ca2+ transporters in zebrafish ionocytes and mammalian renal cells. We also discuss the neuroendocrine responses to acid exposure, and their potential role in ionic compensation. Finally, we identify several knowledge gaps that would benefit from further study.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  4. An individual-based model of Zebrafish population dynamics accounting for energy dynamics

    DEFF Research Database (Denmark)

    Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model...

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

    Science.gov (United States)

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

    2009-01-01

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

  6. Developmental toxicity of thyroid-active compounds in a zebrafish embryotoxicity test

    NARCIS (Netherlands)

    Jomaa, B.; Hermsen, S.A.B.; Kessels, M.Y.; Berg, van den J.H.J.; Peijenburg, A.C.M.; Aarts, J.M.M.J.G.; Piersma, A.H.; Rietjens, I.

    2014-01-01

    Zebrafish embryos were exposed to concentration ranges of selected thyroid-active model compounds in order to assess the applicability of zebrafish-based developmental scoring systems within an alternative testing strategy to detect the developmental toxicity of thyroid-active compounds. Model

  7. [Application of zebrafish model organism in the research of Chinese materia medica].

    Science.gov (United States)

    Chen, Lei; Liu, Yi; Liang, Sheng-Wang

    2012-04-01

    Zebrafish has become an important model organism in many fields of biomedical studies and been increasingly used in Chinese materia medica studies in recent years. This article summarized the achievements and prospect for zebrafish as a pharmacological and toxicological tool in the study and development of Chinese materia medica.

  8. The zebrafish reference genome sequence and its relationship to the human genome.

    NARCIS (Netherlands)

    Howe, K.; Clark, M.D.; Torroja, C.F.; Torrance, J.; Berthelot, C.; Muffato, M.; Collins, J.E.; Humphray, S.; McLaren, K.; Matthews, L.; McLaren, S.; Sealy, I.; Caccamo, M.; Churcher, C.; Scott, C.; Barrett, J.C.; Koch, R.; Rauch, G.J.; White, S.; Chow, W.; Kilian, B.; Quintais, L.T.; Guerra-Assuncao, J.A.; Zhou, Y.; Gu, Y.; Yen, J.; Vogel, J.H.; Eyre, T.; Redmond, S.; Banerjee, R.; Chi, J.; Fu, B.; Langley, E.; Maguire, S.F.; Laird, G.K.; Lloyd, D.; Kenyon, E.; Donaldson, S.; Sehra, H.; Almeida-King, J.; Loveland, J.; Trevanion, S.; Jones, M.; Quail, M.; Willey, D.; Hunt, A.; Burton, J.; Sims, S.; McLay, K.; Plumb, B.; Davis, J.; Clee, C.; Oliver, K.; Clark, R.; Riddle, C.; Elliot, D.; Threadgold, G.; Harden, G.; Ware, D.; Mortimore, B.; Kerry, G.; Heath, P.; Phillimore, B.; Tracey, A.; Corby, N.; Dunn, M.; Johnson, C.; Wood, J.; Clark, S.; Pelan, S.; Griffiths, G.; Smith, M.; Glithero, R.; Howden, P.; Barker, N.; Stevens, C.; Harley, J.; Holt, K.; Panagiotidis, G.; Lovell, J.; Beasley, H.; Henderson, C.; Gordon, D.; Auger, K.; Wright, D.; Collins, J.; Raisen, C.; Dyer, L.; Leung, K.; Robertson, L.; Ambridge, K.; Leongamornlert, D.; McGuire, S.; Gilderthorp, R.; Griffiths, C.; Manthravadi, D.; Nichol, S.; Barker, G.; Whitehead, S.; Kay, M.; Brown, J.; Murnane, C.; Gray, E.; Humphries, M.; Sycamore, N.; Barker, D.; Saunders, D.; Wallis, J.; Babbage, A.; Hammond, S.; Mashreghi-Mohammadi, M.; Barr, L.; Martin, S.; Wray, P.; Ellington, A.; Matthews, N.; Ellwood, M.; Woodmansey, R.; Clark, G.; Cooper, J.; Tromans, A.; Grafham, D.; Skuce, C.; Pandian, R.; Andrews, R.; Harrison, E.; Kimberley, A.; Garnett, J.; Fosker, N.; Hall, R.; Garner, P.; Kelly, D.; Bird, C.; Palmer, S.; Gehring, I.; Berger, A.; Dooley, C.M.; Ersan-Urun, Z.; Eser, C.; Geiger, H.; Geisler, M.; Karotki, L.; Kirn, A.; Konantz, J.; Konantz, M.; Oberlander, M.; Rudolph-Geiger, S.; Teucke, M.; Osoegawa, K.; Zhu, B.; rapp, A.; Widaa, S.; Langford, C.; Yang, F.; Carter, N.P.; Harrow, J.; Ning, Z.; Herrero, J.; Searle, S.M.; Enright, A.; Geisler, R.; Plasterk, R.H.A.; Lee, C.; Westerfield, M.; de Jong, P.J.; Zon, L.I.; Postlethwait, J.H.; Nusslein-Volhard, C.; Hubbard, T.J.; Roest Crollius, H.; Rogers, J.; Stemple, D.L.; Begum, S.; Lloyd, C.; Lanz, C.; Raddatz, G.; Schuster, S.C.

    2013-01-01

    Zebrafish have become a popular organism for the study of vertebrate gene function. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of

  9. A two-scale model for correlation between B cell VDJ usage in zebrafish

    Science.gov (United States)

    Pan, Keyao; Deem, Michael

    2011-03-01

    The zebrafish (Danio rerio) is one of the model animals for study of immunology. The dynamics of the adaptive immune system in zebrafish is similar to that in higher animals. In this work, we built a two-scale model to simulate the dynamics of B cells in primary and secondary immune reactions in zebrafish and to explain the reported correlation between VDJ usage of B cell repertoires in distinct zebrafish. The first scale of the model consists of a generalized NK model to simulate the B cell maturation process in the 10-day primary immune response. The second scale uses a delay ordinary differential equation system to model the immune responses in the 6-month lifespan of zebrafish. The generalized NK model shows that mature B cells specific to one antigen mostly possess a single VDJ recombination. The probability that mature B cells in two zebrafish have the same VDJ recombination increases with the B cell population size or the B cell selection intensity and decreases with the B cell hypermutation rate. The ODE model shows a distribution of correlation in the VDJ usage of the B cell repertoires in two six-month-old zebrafish that is highly similar to that from experiment. This work presents a simple theory to explain the experimentally observed correlation in VDJ usage of distinct zebrafish B cell repertoires after an immune response.

  10. BISPHENOL A EXPOSURE DURING EARLY DEVELOPMENT INDUCES SEX-SPECIFIC CHANGES IN ADULT ZEBRAFISH SOCIAL INTERACTIONS

    Science.gov (United States)

    Weber, Daniel N.; Hoffmann, Raymond G.; Hoke, Elizabeth S.; Tanguay, Robert L.

    2014-01-01

    Developmental bisphenol A (BPA) exposure is associated with adverse behavioral effects, although underlying modes of action remain unclear. Because BPA is a suspected xenoestrogen, the objective was to identify sex-based changes in adult zebrafish social behavior developmentally exposed to BPA (0.0, 0.1 or 1 μM) or one of two control compounds (0.1μM 17β-estradiol [E2], and 0.1 μM GSK4716, a synthetic estrogen-related receptor γ ligand). A test chamber was divided lengthwise so each arena held one fish unable to detect the presence of the other fish. A mirror was inserted at one end of each arena; baseline activity levels were determined without mirror. Arenas were divided into 3, computer-generated zones to represent different distances from mirror image. Circadian rhythm patterns were evaluated at 1–3 (= AM) and 5–8 (= PM) hr postprandial. Adult zebrafish were placed into arenas and monitored by digital camera for 5 min. Total distance traveled, % time spent at mirror image, and number of attacks on mirror image were quantified. E2, GSK4716, and all BPA treatments dampened male activity and altered male circadian activity patterns; there was no marked effect on female activity. BPA induced non-monotonic effects (response curve changes direction within range of concentrations examined) on male % time at mirror only in AM. All treatments produced increased % time at the mirror during PM. Male attacks on the mirror were reduced by BPA exposure only during AM. There were sex-specific effects of developmental BPA on social interactions and time-of-day of observation affected results. PMID:25424546

  11. Aversive cues fail to activate fos expression in the asymmetric olfactory-habenula pathway of zebrafish

    Directory of Open Access Journals (Sweden)

    Tagide N. Decarvalho

    2013-05-01

    Full Text Available The dorsal habenular nuclei of the zebrafish epithalamus have become a valuable model for studying the development of left-right (L-R asymmetry and its function in the vertebrate brain. The bilaterally paired dorsal habenulae exhibit striking differences in size, neuroanatomical organization and molecular properties. They also display differences in their efferent connections with the interpeduncular nucleus (IPN and in their afferent input, with a subset of mitral cells distributed on both sides of the olfactory bulb innervating only the right habenula. Previous studies have implicated the dorsal habenulae in modulating fear/anxiety responses in juvenile and adult zebrafish. It has been suggested that the asymmetric olfactory-habenula pathway (OB-Ha, revealed by selective labeling from an lhx2a:YFP transgene, mediates fear behaviors elicited by alarm pheromone. Here we show that expression of the fam84b gene demarcates a unique region of the right habenula that is the site of innervation by lhx2a:YFP-labeled olfactory axons. Upon ablation of the parapineal, which normally promotes left habenular identity; the fam84b domain is present in both dorsal habenulae and lhx2a:YFP-labeled olfactory bulb neurons form synapses on the left and the right side. To explore the relevance of the asymmetric olfactory projection and how it might influence habenular function, we tested activation of this pathway using odorants known to evoke behaviors. We find that alarm substance or other aversive odors, and attractive cues, activate fos expression in subsets of cells in the olfactory bulb but not in the lhx2a:YFP expressing population. Moreover, neither alarm pheromone nor chondroitin sulfate elicited fos activation in the dorsal habenulae. The results indicate that L-R asymmetry of the epithalamus sets the directionality of olfactory innervation, however, the lhx2a:YFP olfactory-habenula pathway does not appear to mediate fear responses to aversive odorants.

  12. Gemfibrozil and carbamazepine decrease steroid production in zebrafish testes (Danio rerio).

    Science.gov (United States)

    Fraz, Shamaila; Lee, Abigail H; Wilson, Joanna Y

    2018-05-01

    Gemfibrozil (GEM) and carbamazepine (CBZ) are two environmentally relevant pharmaceuticals and chronic exposure of fish to these compounds has decreased androgen levels and fish reproduction in laboratory studies. The main focus of this study was to examine the effects of GEM and CBZ on testicular steroid production, using zebrafish as a model species. Chronic water borne exposures of adult zebrafish to 10 μg/L of GEM and CBZ were conducted and the dosing was confirmed by chemical analysis of water as 17.5 ± 1.78 and 11.2 ± 1.08 μg/L respectively. A 67 day exposure led to reduced reproductive output and lowered whole body, plasma, and testicular 11-ketotestosterone (11-KT). Testicular production of 11-KT was examined post exposure (42 days) using ex vivo cultures to determine basal and stimulated steroid production. The goal was to ascertain the step impaired in the steroidogenic pathway by each compound. Ex vivo 11-KT production in testes from males chronically exposed to GEM and CBZ was lower than that from unexposed males. Although hCG, 25-OH cholesterol, and pregnenolone stimulation increased 11-KT production in all treatment groups over basal levels, hCG stimulated 11-KT production remained significantly less in testes from exposed males compared to controls. 25-OH cholesterol and pregnenolone stimulated 11-KT production was similar between GEM and control groups but the CBZ group had lower 11-KT production than controls with both stimulants. We therefore propose that chronic GEM and CBZ exposure can reduce production of 11-KT in testes through direct effects independent of mediation through HPG axis. The biochemical processes for steroid production appear un-impacted by GEM exposure; while CBZ exposure may influence steroidogenic enzyme expression or function. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. The Zebrafish GenomeWiki: a crowdsourcing approach to connect the long tail for zebrafish gene annotation

    OpenAIRE

    Singh, Meghna; Bhartiya, Deeksha; Maini, Jayant; Sharma, Meenakshi; Singh, Angom Ramcharan; Kadarkaraisamy, Subburaj; Rana, Rajiv; Sabharwal, Ankit; Nanda, Srishti; Ramachandran, Aravindhakshan; Mittal, Ashish; Kapoor, Shruti; Sehgal, Paras; Asad, Zainab; Kaushik, Kriti

    2014-01-01

    A large repertoire of gene-centric data has been generated in the field of zebrafish biology. Although the bulk of these data are available in the public domain, most of them are not readily accessible or available in nonstandard formats. One major challenge is to unify and integrate these widely scattered data sources. We tested the hypothesis that active community participation could be a viable option to address this challenge. We present here our approach to create standards for assimilat...

  14. Behavioural changes in response to sound exposure and no spatial avoidance of noisy conditions in captive zebrafish

    Directory of Open Access Journals (Sweden)

    Yik Yaw (Errol eNeo

    2015-02-01

    Full Text Available Auditory sensitivity in fish serves various important functions, but also makes fish susceptible to noise pollution. Human-generated sounds may affect behavioural patterns of fish, both in natural conditions and in captivity. Fish are often kept for consumption in aquaculture, on display in zoos and hobby aquaria, and for medical sciences in research facilities, but little is known about the impact of ambient sounds in fish tanks. In this study, we conducted two indoor exposure experiments with zebrafish (Danio rerio. The first experiment demonstrated that exposure to moderate sound levels (112 dB re 1 μPa can affect the swimming behaviour of fish by changing group cohesion, swimming speed and swimming height. Effects were brief for both continuous and intermittent noise treatments. In the second experiment, fish could influence exposure to higher sound levels by swimming freely between an artificially noisy fish tank (120-140 dB re 1 μPa and another with ambient noise levels (89 dB re 1 μPa. Despite initial startle responses, and a brief period in which many individuals in the noisy tank dived down to the bottom, there was no spatial avoidance or noise-dependent tank preference at all. The frequent exchange rate of about 60 fish passages per hour between tanks was not affected by continuous or intermittent exposures. In conclusion, small groups of captive zebrafish were able to detect sounds already at relatively low sound levels and adjust their behaviour to it. Relatively high sound levels were at least at the on-set disturbing, but did not lead to spatial avoidance. Further research is needed to show whether zebrafish are not able to avoid noisy areas or just not bothered. Quantitatively, these data are not directly applicable to other fish species or other fish tanks, but they do indicate that sound exposure may affect fish behaviour in any captive condition.

  15. Behavioral changes in response to sound exposure and no spatial avoidance of noisy conditions in captive zebrafish.

    Science.gov (United States)

    Neo, Yik Yaw; Parie, Lisa; Bakker, Frederique; Snelderwaard, Peter; Tudorache, Christian; Schaaf, Marcel; Slabbekoorn, Hans

    2015-01-01

    Auditory sensitivity in fish serves various important functions, but also makes fish susceptible to noise pollution. Human-generated sounds may affect behavioral patterns of fish, both in natural conditions and in captivity. Fish are often kept for consumption in aquaculture, on display in zoos and hobby aquaria, and for medical sciences in research facilities, but little is known about the impact of ambient sounds in fish tanks. In this study, we conducted two indoor exposure experiments with zebrafish (Danio rerio). The first experiment demonstrated that exposure to moderate sound levels (112 dB re 1 μPa) can affect the swimming behavior of fish by changing group cohesion, swimming speed and swimming height. Effects were brief for both continuous and intermittent noise treatments. In the second experiment, fish could influence exposure to higher sound levels by swimming freely between an artificially noisy fish tank (120-140 dB re 1 μPa) and another with ambient noise levels (89 dB re 1 μPa). Despite initial startle responses, and a brief period in which many individuals in the noisy tank dived down to the bottom, there was no spatial avoidance or noise-dependent tank preference at all. The frequent exchange rate of about 60 fish passages per hour between tanks was not affected by continuous or intermittent exposures. In conclusion, small groups of captive zebrafish were able to detect sounds already at relatively low sound levels and adjust their behavior to it. Relatively high sound levels were at least at the on-set disturbing, but did not lead to spatial avoidance. Further research is needed to show whether zebrafish are not able to avoid noisy areas or just not bothered. Quantitatively, these data are not directly applicable to other fish species or other fish tanks, but they do indicate that sound exposure may affect fish behavior in any captive condition.

  16. Inhibition of vascular endothelial growth factor signaling facilitates liver repair from acute ethanol-induced injury in zebrafish

    Directory of Open Access Journals (Sweden)

    Changwen Zhang

    2016-11-01

    Full Text Available Alcoholic liver disease (ALD results from alcohol overconsumption and is among the leading causes of liver-related morbidity and mortality worldwide. Elevated expression of vascular endothelial growth factor (VEGF and its receptors has been observed in ALD, but how it contributes to ALD pathophysiology is unclear. Here, we investigated the impact of VEGF signaling inhibition on an established zebrafish model of acute alcoholic liver injury. Kdrl activity was blocked by chemical inhibitor treatment or by genetic mutation. Exposing 4-day-old zebrafish larvae to 2% ethanol for 24 h induced hepatic steatosis, angiogenesis and fibrogenesis. The liver started self-repair once ethanol was removed. Although inhibiting Kdrl did not block the initial activation of hepatic stellate cells during ethanol treatment, it suppressed their proliferation, extracellular matrix protein deposition and fibrogenic gene expression after ethanol exposure, thus enhancing the liver repair. It also ameliorated hepatic steatosis and attenuated hepatic angiogenesis that accelerated after the ethanol treatment. qPCR showed that hepatic stellate cells are the first liver cell type to increase the expression of VEGF ligand and receptor genes in response to ethanol exposure. Both hepatic stellate cells and endothelial cells, but not hepatic parenchymal cells, expressed kdrl upon ethanol exposure and were likely the direct targets of Kdrl inhibition. Ethanol-induced steatosis and fibrogenesis still occurred in cloche mutants that have hepatic stellate cells but lack hepatic endothelial cells, and Kdrl inhibition suppressed both phenotypes in the mutants. These results suggest that VEGF signaling mediates interactions between activated hepatic stellate cells and hepatocytes that lead to steatosis. Our study demonstrates the involvement of VEGF signaling in regulating sustained liver injuries after acute alcohol exposure. It also provides a proof of principle of using the

  17. A zebrafish model for Waardenburg syndrome type IV reveals diverse roles for Sox10 in the otic vesicle.

    Science.gov (United States)

    Dutton, Kirsten; Abbas, Leila; Spencer, Joanne; Brannon, Claire; Mowbray, Catriona; Nikaido, Masataka; Kelsh, Robert N; Whitfield, Tanya T

    2009-01-01

    In humans, mutations in the SOX10 gene are a cause of the auditory-pigmentary disorder Waardenburg syndrome type IV (WS4) and related variants. SOX10 encodes an Sry-related HMG box protein essential for the development of the neural crest; deafness in WS4 and other Waardenburg syndromes is usually attributed to loss of neural-crest-derived melanocytes in the stria vascularis of the cochlea. However, SOX10 is strongly expressed in the developing otic vesicle and so direct roles for SOX10 in the otic epithelium might also be important. Here, we examine the otic phenotype of zebrafish sox10 mutants, a model for WS4. As a cochlea is not present in the fish ear, the severe otic phenotype in these mutants cannot be attributed to effects on this tissue. In zebrafish sox10 mutants, we see abnormalities in all otic placodal derivatives. Gene expression studies indicate deregulated expression of several otic genes, including fgf8, in sox10 mutants. Using a combination of mutant and morphant data, we show that the three sox genes belonging to group E (sox9a, sox9b and sox10) provide a link between otic induction pathways and subsequent otic patterning: they act redundantly to maintain sox10 expression throughout otic tissue and to restrict fgf8 expression to anterior macula regions. Single-cell labelling experiments indicate a small and transient neural crest contribution to the zebrafish ear during normal development, but this is unlikely to account for the strong defects seen in the sox10 mutant. We discuss the implication that the deafness in WS4 patients with SOX10 mutations might reflect a haploinsufficiency for SOX10 in the otic epithelium, resulting in patterning and functional abnormalities in the inner ear.

  18. Pharmacologic modeling of primary mitochondrial respiratory chain dysfunction in zebrafish.

    Science.gov (United States)

    Byrnes, James; Ganetzky, Rebecca; Lightfoot, Richard; Tzeng, Michael; Nakamaru-Ogiso, Eiko; Seiler, Christoph; Falk, Marni J

    2017-07-18

    Mitochondrial respiratory chain (RC) disease is a heterogeneous and highly morbid group of energy deficiency disorders for which no proven effective therapies exist. Robust vertebrate animal models of primary RC dysfunction are needed to explore the effects of variation in RC disease subtypes, tissue-specific manifestations, and major pathogenic factors contributing to each disorder, as well as their pre-clinical response to therapeutic candidates. We have developed a series of zebrafish (Danio rerio) models that inhibit, to variable degrees, distinct aspects of RC function, and enable quantification of animal development, survival, behaviors, and organ-level treatment effects as well as effects on mitochondrial biochemistry and physiology. Here, we characterize four pharmacologic inhibitor models of mitochondrial RC dysfunction in early larval zebrafish, including rotenone (complex I inhibitor), azide (complex IV inhibitor), oligomycin (complex V inhibitor), and chloramphenicol (mitochondrial translation inhibitor that leads to multiple RC complex dysfunction). A range of concentrations and exposure times of each RC inhibitor were systematically evaluated on early larval development, animal survival, integrated behaviors (touch and startle responses), organ physiology (brain death, neurologic tone, heart rate), and fluorescence-based analyses of mitochondrial physiology in zebrafish skeletal muscle. Pharmacologic RC inhibitor effects were validated by spectrophotometric analysis of Complex I, II and IV enzyme activities, or relative quantitation of ATP levels in larvae. Outcomes were prioritized that utilize in vivo animal imaging and quantitative behavioral assessments, as may optimally inform the translational potential of pre-clinical drug screens for future clinical study in human mitochondrial disease subjects. The RC complex inhibitors each delayed early embryo development, with short-term exposures of these three agents or chloramphenicol from 5 to 7 days

  19. 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

  20. ZebrafishMiner: an open source software for interactive evaluation of domain-specific fluorescence in zebrafish

    Directory of Open Access Journals (Sweden)

    Reischl Markus

    2017-09-01

    Full Text Available High-throughput microscopy makes it possible to observe the morphology of zebrafish on large scale to quantify genetic, toxic or drug effects. The image acquisition is done by automated microscopy, images are evaluated automatically by image processing pipelines, tailored specifically to the requirements of the scientific question. The transfer of such algorithms to other projects, however, is complex due to missing guidelines and lack of mathematical or programming knowledge. In this work, we implement an image processing pipeline for automatic fluorescence quantification in user-defined domains of zebrafish embryos and larvae of different age. The pipeline is capable of detecting embryos and larvae in image stacks and quantifying domain activity. To make this protocol available to the community, we developed an open source software package called „ZebrafishMiner“ which guides the user through all steps of the processing pipeline and makes the algorithms available and easy to handle. We implemented all routines in an MATLAB-based graphical user interface (GUI that gives the user control over all image processing parameters. The software is shipped with a manual of 30 pages and three tutorial datasets, which guide the user through the manual step by step. It can be downloaded at https://sourceforge.net/projects/scixminer/.

  1. Cross-Modal Learning between Visual and Vibration Signals in Zebrafish Danio Rerio

    Directory of Open Access Journals (Sweden)

    Mu-Yun Wang

    2011-10-01

    Full Text Available Animals are always integrating environmental information from multiple sensory modalities, but the mechanisms underneath are highly underexploited. Crossmodal interactions in animal perception have been found in several species including human, mice and flies. Here we subjected zebrafish as model because its genetic effects on brain and sense organ development are well studied, but the attentional processes are mainly unexplored. Zebrafish show impressive behaviour capabilities with relatively small or “simple” brains which make their nervous system relatively more accessible to experimentation than large-brained mammals. When conditioned with both vision and vibration signals, zebrafish were able to make higher correct choices than only one sensation. After multimodal training, zebrafish were also able to transfer the memory to unimodal conditioning when only given vision or vibration signals. This study provided basic findings for how animals process multimodal sensory from the environment, and showed crossmodal interactions in zebrafish for the first time.

  2. Zebrafish models of cardiovascular diseases and their applications in herbal medicine research.

    Science.gov (United States)

    Seto, Sai-Wang; Kiat, Hosen; Lee, Simon M Y; Bensoussan, Alan; Sun, Yu-Ting; Hoi, Maggie P M; Chang, Dennis

    2015-12-05

    The zebrafish (Danio rerio) has recently become a powerful animal model for cardiovascular research and drug discovery due to its ease of maintenance, genetic manipulability and ability for high-throughput screening. Recent advances in imaging techniques and generation of transgenic zebrafish have greatly facilitated in vivo analysis of cellular events of cardiovascular development and pathogenesis. More importantly, recent studies have demonstrated the functional similarity of drug metabolism systems between zebrafish and humans, highlighting the clinical relevance of employing zebrafish in identifying lead compounds in Chinese herbal medicine with potential beneficial cardiovascular effects. This paper seeks to summarise the scope of zebrafish models employed in cardiovascular studies and the application of these research models in Chinese herbal medicine to date. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  3. Somatic mutagenesis with a Sleeping Beauty transposon system leads to solid tumor formation in zebrafish.

    Directory of Open Access Journals (Sweden)

    Maura McGrail

    2011-04-01

    Full Text Available Large-scale sequencing of human cancer genomes and mouse transposon-induced tumors has identified a vast number of genes mutated in different cancers. One of the outstanding challenges in this field is to determine which genes, when mutated, contribute to cellular transformation and tumor progression. To identify new and conserved genes that drive tumorigenesis we have developed a novel cancer model in a distantly related vertebrate species, the zebrafish, Danio rerio. The Sleeping Beauty (SB T2/Onc transposon system was adapted for somatic mutagenesis in zebrafish. The carp ß-actin promoter was cloned into T2/Onc to create T2/OncZ. Two transgenic zebrafish lines that contain large concatemers of T2/OncZ were isolated by injection of linear DNA into the zebrafish embryo. The T2/OncZ transposons were mobilized throughout the zebrafish genome from the transgene array by injecting SB11 transposase RNA at the 1-cell stage. Alternatively, the T2/OncZ zebrafish were crossed to a transgenic line that constitutively expresses SB11 transposase. T2/OncZ transposon integration sites were cloned by ligation-mediated PCR and sequenced on a Genome Analyzer II. Between 700-6800 unique integration events in individual fish were mapped to the zebrafish genome. The data show that introduction of transposase by transgene expression or RNA injection results in an even distribution of transposon re-integration events across the zebrafish genome. SB11 mRNA injection resulted in neoplasms in 10% of adult fish at ∼10 months of age. T2/OncZ-induced zebrafish tumors contain many mutated genes in common with human and mouse cancer genes. These analyses validate our mutagenesis approach and provide additional support for the involvement of these genes in human cancers. The zebrafish T2/OncZ cancer model will be useful for identifying novel and conserved genetic drivers of human cancers.

  4. A microarray analysis of sex- and gonad-biased gene expression in the zebrafish: Evidence for masculinization of the transcriptome

    Directory of Open Access Journals (Sweden)

    Mo Qianxing

    2009-12-01

    that transcriptomic sex differences in D. rerio are widespread despite the apparent absence of heterogamety. These differences likely make important contributions to phenotypic sexual dimorphism in adult zebrafish; thus, from an evolutionary standpoint, the precise roles of sex-specific selection and sexual conflict in the evolution of sexually dimorphic gene expression are very important. The results of our study and others like it set the stage for further work aimed at directly addressing this exciting issue in comparative genomics.

  5. Characterization of housekeeping genes in zebrafish: male-female differences and effects of tissue type, developmental stage and chemical treatment

    Directory of Open Access Journals (Sweden)

    Callard Gloria V

    2008-11-01

    different reference genes to measure suppression of cyp19a1b by an estrogen receptor antagonist and induction of cyp1a by an arylhydrocarbon receptor agonist, the direction and magnitude of effects with stable and unstable genes differed. Conclusion This study provides data that can be expected to aid zebrafish researchers in their initial choice of housekeeping genes for future studies, but underlines the importance of further validating housekeeping genes for each new experimental paradigm and fish species.

  6. Intraperitoneal Exposure to Nano/Microparticles of Fullerene (C60) Increases Acetylcholinesterase Activity and Lipid Peroxidation in Adult Zebrafish (Danio rerio) Brain

    Science.gov (United States)

    Dal Forno, Gonzalo Ogliari; Kist, Luiza Wilges; de Azevedo, Mariana Barbieri; Fritsch, Rachel Seemann; Pereira, Talita Carneiro Brandão; Britto, Roberta Socoowski; Guterres, Sílvia Stanisçuaski; Külkamp-Guerreiro, Irene Clemes; Bonan, Carla Denise; Monserrat, José María; Bogo, Maurício Reis

    2013-01-01

    Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60 are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60 exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60 nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60 nano/microparticles on the protein (in vitro results) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60 exposure. PMID:23865059

  7. Understanding the transformation, speciation, and hazard potential of copper particles in a model septic tank system using zebrafish to monitor the effluent.

    Science.gov (United States)

    Lin, Sijie; Taylor, Alicia A; Ji, Zhaoxia; Chang, Chong Hyun; Kinsinger, Nichola M; Ueng, William; Walker, Sharon L; Nel, André E

    2015-02-24

    Although copper-containing nanoparticles are used in commercial products such as fungicides and bactericides, we presently do not understand the environmental impact on other organisms that may be inadvertently exposed. In this study, we used the zebrafish embryo as a screening tool to study the potential impact of two nano Cu-based materials, CuPRO and Kocide, in comparison to nanosized and micron-sized Cu and CuO particles in their pristine form (0-10 ppm) as well as following their transformation in an experimental wastewater treatment system. This was accomplished by construction of a modeled domestic septic tank system from which effluents could be retrieved at different stages following particle introduction (10 ppm). The Cu speciation in the effluent was identified as nondissolvable inorganic Cu(H2PO2)2 and nondiffusible organic Cu by X-ray diffraction, inductively coupled plasma mass spectrometry (ICP-MS), diffusive gradients in thin-films (DGT), and Visual MINTEQ software. While the nanoscale materials, including the commercial particles, were clearly more potent (showing 50% hatching interference above 0.5 ppm) than the micron-scale particulates with no effect on hatching up to 10 ppm, the Cu released from the particles in the septic tank underwent transformation into nonbioavailable species that failed to interfere with the function of the zebrafish embryo hatching enzyme. Moreover, we demonstrate that the addition of humic acid, as an organic carbon component, could lead to a dose-dependent decrease in Cu toxicity in our high content zebrafish embryo screening assay. Thus, the use of zebrafish embryo screening, in combination with the effluents obtained from a modeled exposure environment, enables a bioassay approach to follow the change in the speciation and hazard potential of Cu particles instead of difficult-to-perform direct particle tracking.

  8. mPeriod2 Brdm1 and other single Period mutant mice have normal food anticipatory activity.

    Science.gov (United States)

    Pendergast, Julie S; Wendroth, Robert H; Stenner, Rio C; Keil, Charles D; Yamazaki, Shin

    2017-11-14

    Animals anticipate the timing of food availability via the food-entrainable oscillator (FEO). The anatomical location and timekeeping mechanism of the FEO are unknown. Several studies showed the circadian gene, Period 2, is critical for FEO timekeeping. However, other studies concluded that canonical circadian genes are not essential for FEO timekeeping. In this study, we re-examined the effects of the Per2 Brdm1 mutation on food entrainment using methods that have revealed robust food anticipatory activity in other mutant lines. We examined food anticipatory activity, which is the output of the FEO, in single Period mutant mice. Single Per1, Per2, and Per3 mutant mice had robust food anticipatory activity during restricted feeding. In addition, we found that two different lines of Per2 mutant mice (ldc and Brdm1) anticipated restricted food availability. To determine if FEO timekeeping persisted in the absence of the food cue, we assessed activity during fasting. Food anticipatory (wheel-running) activity in all Period mutant mice was also robust during food deprivation. Together, our studies demonstrate that the Period genes are not necessary for the expression of food anticipatory activity.

  9. Expression of the Circadian Clock Gene Period2 in the Hippocampus: Possible Implications for Synaptic Plasticity and Learned Behaviour

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    Louisa M-C Wang

    2009-05-01

    Full Text Available Genes responsible for generating circadian oscillations are expressed in a variety of brain regions not typically associated with circadian timing. The functions of this clock gene expression are largely unknown, and in the present study we sought to explore the role of the Per2 (Period 2 gene in hippocampal physiology and learned behaviour. We found that PER2 protein is highly expressed in hippocampal pyramidal cell layers and that the expression of both protein and mRNA varies with a circadian rhythm. The peaks of these rhythms occur in the late night or early morning and are almost 180° out-of-phase with the expression rhythms measured from the suprachiasmatic nucleus of the same animals. The rhythms in Per2 expression are autonomous as they are present in isolated hippocampal slices maintained in culture. Physiologically, Per2-mutant mice exhibit abnormal long-term potentiation. The underlying mechanism is suggested by the finding that levels of phosphorylated cAMP-response-element-binding protein, but not phosphorylated extracellular-signal-regulated kinase, are reduced in hippocampal tissue from mutant mice. Finally, Per2-mutant mice exhibit deficits in the recall of trace, but not cued, fear conditioning. Taken together, these results provide evidence that hippocampal cells contain an autonomous circadian clock. Furthermore, the clock gene Per2 may play a role in the regulation of long-term potentiation and in the recall of some forms of learned behaviour.

  10. Quaternary and tertiary aldoxime antidotes for organophosphate exposure in a zebrafish model system

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Hayden R. [Department of Biology, Whittier College, Whittier, CA 90608 (United States); Radić, Zoran; Taylor, Palmer [Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093-0650 (United States); Fradinger, Erica A., E-mail: efrading@whittier.edu [Department of Biology, Whittier College, Whittier, CA 90608 (United States)

    2015-04-15

    The zebrafish is rapidly becoming an important model system for screening of new therapeutics. Here we evaluated the zebrafish as a potential pharmacological model for screening novel oxime antidotes to organophosphate (OP)-inhibited acetylcholinesterase (AChE). The k{sub i} values determined for chlorpyrifos oxon (CPO) and dichlorvos (DDVP) showed that CPO was a more potent inhibitor of both human and zebrafish AChE, but overall zebrafish AChE was less sensitive to OP inhibition. In contrast, aldoxime antidotes, the quaternary ammonium 2-PAM and tertiary amine RS-194B, showed generally similar overall reactivation kinetics, k{sub r}, in both zebrafish and human AChE. However, differences between the K{sub ox} and k{sub 2} constants suggest that zebrafish AChE associates more tightly with oximes, but has a slower maximal reactivation rate than human AChE. Homology modeling suggests that these kinetic differences result from divergences in the amino acids lining the entrance to the active site gorge. Although 2-PAM had the more favorable in vitro reactivation kinetics, RS-194B was more effective antidote in vivo. In intact zebrafish embryos, antidotal treatment with RS-194B rescued embryos from OP toxicity, whereas 2-PAM had no effect. Dechorionation of the embryos prior to antidotal treatment allowed both 2-PAM and RS-194B to rescue zebrafish embryos from OP toxicity. Interestingly, RS-194B and 2-PAM alone increased cholinergic motor activity in dechorionated embryos possibly due to the reversible inhibition kinetics, K{sub i} and αK{sub i}, of the oximes. Together these results demonstrate that the zebrafish at various developmental stages provides an excellent model for investigating membrane penetrant antidotes to OP exposure. - Highlights: • Zebrafish AChE shares significant structural similarities with human AChE. • OP-inhibited zebrafish and human AChE exhibit similar reactivation kinetics. • The zebrafish chorion is permeable to BBB penetrant and not

  11. Transient knockdown of tyrosine hydroxylase during development has persistent effects on behaviour in adult zebrafish (Danio rerio.

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    Isabel Formella

    Full Text Available Abnormal dopamine (DA signaling is often suggested as causative in schizophrenia. The other prominent hypothesis for this disorder, largely driven by epidemiological data, is that certain adverse events during the early stages of brain development increase an individual's risk of developing schizophrenia later in life. However, the clinical and preclinical literature consistently implicates behavioural, cognitive, and pharmacological abnormalities, implying that DA signaling is abnormal in the adult brain. How can we reconcile these two major hypotheses underlying much of the clinical and basic research into schizophrenia? In this study we have transiently knocked down tyrosine hydroxylase (TH, the rate limiting enzyme in DA synthesis gene expression in the early stages of brain development in zebrafish using morpholinos. We show that by adulthood, TH and DA levels have returned to normal and basic DA-mediated behaviours, such as locomotion, are also normal. However, when they were exposed to a novel environment the levels of freezing and immediate positioning in deeper zones were significantly reduced in these adult fish. The neurochemistry underlying these behaviours is complex, and the exact mechanisms for these abnormal behaviours remains unknown. This study demonstrates that early transient alterations in DA ontogeny can produce persistent alterations in adult brain function and suggests that the zebrafish may be a promising model animal for future studies directed at clarifying the basic neurodevelopmental mechanisms behind complex psychiatric disease.

  12. A genetic screen for vascular mutants in zebrafish reveals dynamic roles for Vegf/Plcg1 signaling during artery development.

    Science.gov (United States)

    Covassin, L D; Siekmann, A F; Kacergis, M C; Laver, E; Moore, J C; Villefranc, J A; Weinstein, B M; Lawson, N D

    2009-05-15

    In this work we describe a forward genetic approach to identify mutations that affect blood vessel development in the zebrafish. By applying a haploid screening strategy in a transgenic background that allows direct visualization of blood vessels, it was possible to identify several classes of mutant vascular phenotypes. Subsequent characterization of mutant lines revealed that defects in Vascular endothelial growth factor (Vegf) signaling specifically affected artery development. Comparison of phenotypes associated with different mutations within a functional zebrafish Vegf receptor-2 ortholog (referred to as kdr-like, kdrl) revealed surprisingly varied effects on vascular development. In parallel, we identified an allelic series of mutations in phospholipase c gamma 1 (plcg1). Together with in vivo structure-function analysis, our results suggest a requirement for Plcg1 catalytic activity downstream of receptor tyrosine kinases. We further find that embryos lacking both maternal and zygotic plcg1 display more severe defects in artery differentiation but are otherwise similar to zygotic mutants. Finally, we demonstrate through mosaic analysis that plcg1 functions autonomously in endothelial cells. Together our genetic analyses suggest that Vegf/Plcg1 signaling acts at multiple time points and in different signaling contexts to mediate distinct aspects of artery development.

  13. Laterotopic representation of left-right information onto the dorso-ventral axis of a zebrafish midbrain target nucleus.

    Science.gov (United States)

    Aizawa, Hidenori; Bianco, Isaac H; Hamaoka, Takanori; Miyashita, Toshio; Uemura, Osamu; Concha, Miguel L; Russell, Claire; Wilson, Stephen W; Okamoto, Hitoshi

    2005-02-08

    The habenulae are part of an evolutionarily highly conserved limbic-system conduction pathway that connects telencephalic nuclei to the interpeduncular nucleus (IPN) of the midbrain . In zebrafish, unilateral activation of the Nodal signaling pathway in the left brain specifies the laterality of the asymmetry of habenular size . We show "laterotopy" in the habenulo-interpeduncular projection in zebrafish, i.e., the stereotypic, topographic projection of left-sided habenular axons to the dorsal region of the IPN and of right-sided habenular axons to the ventral IPN. This asymmetric projection is accounted for by a prominent left-right (LR) difference in the size ratio of the medial and lateral habenular sub-nuclei, each of which specifically projects either to ventral or dorsal IPN targets. Asymmetric Nodal signaling directs the orientation of laterotopy but is dispensable for the establishment of laterotopy itself. Our results reveal a mechanism by which information distributed between left and right sides of the brain can be transmitted bilaterally without loss of LR coding, which may play a crucial role in functional lateralization of the vertebrate brain .

  14. The power of projectomes: genetic mosaic labeling in the larval zebrafish brain reveals organizing principles of sensory circuits.

    Science.gov (United States)

    Robles, Estuardo

    2017-09-01

    In no vertebrate species do we possess an accurate, comprehensive tally of neuron types in the brain. This is in no small part due to the vast diversity of neuronal types that comprise complex vertebrate nervous systems. A fundamental goal of neuroscience is to construct comprehensive catalogs of cell types defined by structure, connectivity, and physiological response properties. This type of information will be invaluable for generating models of how assemblies of neurons encode and distribute sensory information and correspondingly alter behavior. This review summarizes recent efforts in the larval zebrafish to construct sensory projectomes, comprehensive analyses of axonal morphologies in sensory axon tracts. Focusing on the olfactory and optic tract, these studies revealed principles of sensory information processing in the olfactory and visual systems that could not have been directly quantified by other methods. In essence, these studies reconstructed the optic and olfactory tract in a virtual manner, providing insights into patterns of neuronal growth that underlie the formation of sensory axon tracts. Quantitative analysis of neuronal diversity revealed organizing principles that determine information flow through sensory systems in the zebrafish that are likely to be conserved across vertebrate species. The generation of comprehensive cell type classifications based on structural, physiological, and molecular features will lead to testable hypotheses on the functional role of individual sensory neuron subtypes in controlling specific sensory-evoked behaviors.

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

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    Tânia Martins

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

  16. Mitochondrial behavior during oogenesis in zebrafish: a confocal microscopy analysis.

    Science.gov (United States)

    Zhang, Yong-Zhong; Ouyang, Ying-Chun; Hou, Yi; Schatten, Heide; Chen, Da-Yuan; Sun, Qing-Yuan

    2008-03-01

    The behavior of mitochondria during early oogenesis remains largely unknown in zebrafish. We used three mitochondrial probes (Mito Tracker Red CMXRos, Mito Tracker Green FM, and JC-1) to stain early zebrafish oocyte mitochondria, and confocal microscopy to analyze mitochondrial aggregation and distribution. By using fluorescence recovery after photobleaching (FRAP), we traced mitochondrial movement. The microtubule assembly inhibitor nocodazole and microfilament inhibitor cytochalasin B (CB) were used to analyze the role of microtubules and microfilaments on mitochondrial movement. By using the dual emission probe, JC-1, and oxidative phosphorylation uncoupler, carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), we determined the distribution of active and inactive (low-active) mitochondria. Green/red fluorescence ratios of different sublocations in different oocyte groups stained by JC-1 were detected in merged (green and red) images. Our results showed that mitochondria exhibited a unique distribution pattern in early zebrafish oocytes. They tended to aggregate into large clusters in early stage I oocytes, but in a threadlike state in latter stage I oocytes. We detected a lower density mitochondrial area and a higher density mitochondrial area on opposite sides of the germinal vesicle. The green/red fluorescence ratios in different sublocations in normal oocytes were about 1:1. This implies that active mitochondria were distributed in all sublocations. FCCP treatment caused significant increases in the ratios. CB and nocodazole treatment caused an increase of the ratios in clusters and mitochondrial cloud, but not in dispersed areas. Mitochondria in different sublocations underwent fast dynamic movement. Inhibition or disruption of microtubules or microfilaments resulted in even faster mitochondrial free movement.

  17. Comparative Developmental Toxicity of Flavonoids Using an Integrative Zebrafish System.

    Science.gov (United States)

    Bugel, Sean M; Bonventre, Josephine A; Tanguay, Robert L

    2016-11-01

    Flavonoids are a large, structurally diverse class of bioactive naturally occurring chemicals commonly detected in breast milk, soy based infant formulas, amniotic fluid, and fetal cord blood. The potential for pervasive early life stage exposures raises concerns for perturbation of embryogenesis, though developmental toxicity and bioactivity information is limited for many flavonoids. Therefore, we evaluated a suite of 24 flavonoid and flavonoid-like chemicals using a zebrafish embryo-larval toxicity bioassay-an alternative model for investigating developmental toxicity of environmentally relevant chemicals. Embryos were exposed to 1-50 µM of each chemical from 6 to 120 h postfertilization (hpf), and assessed for 26 adverse developmental endpoints at 24, 72, and 120 hpf. Behavioral changes were evaluated in morphologically normal animals at 24 and 72 hpf, at 120 hpf using a larval photomotor response (LPR) assay. Gene expression was comparatively evaluated for all compounds for effects on biomarker transcripts indicative of AHR (cyp1a) and ER (cyp19a1b, esr1, lhb, vtg) pathway bioactivity. Overall, 15 of 24 flavonoids elicited adverse effects on one or more of the developmental or behavioral endpoints. Hierarchical clustering and principle component analyses compared toxicity profiles and identified 3 distinct groups of bioactive flavonoids. Despite robust induction of multiple estrogen-responsive biomarkers, co-exposure with ER and GPER antagonists did not ameliorate toxicity, suggesting ER-independence and alternative modes of action. Taken together, these studies demonstrate that development is sensitive to perturbation by bioactive flavonoids in zebrafish that are not related to traditional estrogen receptor mode of action pathways. This integrative zebrafish platform provides a useful framework for evaluating flavonoid developmental toxicity and hazard prioritization. © The Author 2016. Published by Oxford University Press on behalf of the Society of

  18. Identification and functional characterization of cardiac pacemaker cells in zebrafish.

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    Federico Tessadori

    Full Text Available In the mammalian heart a conduction system of nodes and conducting cells generates and transduces the electrical signals evoking myocardial contractions. Specialized pacemaker cells initiating and controlling cardiac contraction rhythmicity are localized in an anatomically identifiable structure of myocardial origin, the sinus node. We previously showed that in mammalian embryos sinus node cells originate from cardiac progenitors expressing the transcription factors T-box transcription factor 3 (Tbx3 and Islet-1 (Isl1. Although cardiac development and function are strikingly conserved amongst animal classes, in lower vertebrates neither structural nor molecular distinguishable components of a conduction system have been identified, questioning its evolutionary origin. Here we show that zebrafish embryos lacking the LIM/homeodomain-containing transcription factor Isl1 display heart rate defects related to pacemaker dysfunction. Moreover, 3D reconstructions of gene expression patterns in the embryonic and adult zebrafish heart led us to uncover a previously unidentified, Isl1-positive and Tbx2b-positive region in the myocardium at the junction of the sinus venosus and atrium. Through their long interconnecting cellular protrusions the identified Isl1-positive cells form a ring-shaped structure. In vivo labeling of the Isl1-positive cells by transgenic technology allowed their isolation and electrophysiological characterization, revealing their unique pacemaker activity. In conclusion we demonstrate that Isl1-expressing cells, organized as a ring-shaped structure around the venous pole, hold the pacemaker function in the adult zebrafish heart. We have thereby identified an evolutionary conserved, structural and molecular distinguishable component of the cardiac conduction system in a lower vertebrate.

  19. The genetics of hair-cell function in zebrafish.

    Science.gov (United States)

    Nicolson, Teresa

    2017-09-01

    Our ears are remarkable sensory organs, providing the important senses of balance and hearing. The complex structure of the inner ear, or 'labyrinth', along with the assorted neuroepithelia, have evolved to detect head movements and sounds with impressive sensitivity. The rub is that the inner ear is highly vulnerable to genetic lesions and environmental insults. According to National Institute of Health estimates, hearing loss is one of the most commonly inherited or acquired sensorineural diseases. To understand the causes of deafness and balance disorders, it is imperative to understand the underlying biology of the inner ear, especially the inner workings of the sensory receptors. These receptors, which are termed hair cells, are particularly susceptible to genetic mutations - more than two dozen genes are associated with defects in this cell type in humans. Over the past decade, a substantial amount of progress has been made in working out the molecular basis of hair-cell function using vertebrate animal models. Given the transparency of the inner ear and the genetic tools that are available, zebrafish have become an increasingly popular animal model for the study of deafness and vestibular dysfunction. Mutagenesis screens for larval defects in hearing and balance have been fruitful in finding key components, many of which have been implicated in human deafness. This review will focus on the genes that are required for hair-cell function in zebrafish, with a particular emphasis on mechanotransduction. In addition, the generation of new tools available for the characterization of zebrafish hair-cell mutants will be discussed.

  20. L-histidine enhances learning in stressed zebrafish

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    L.P.V. Cofiel

    2009-01-01

    Full Text Available The aim of the present study was to determine the effect of the histaminergic precursor L-histidine and the H3 receptor antagonist thioperamide on the learning process of zebrafish submitted or not to confinement stress. On each of the 5 consecutive days of experiment (D1, D2, D3, D4, D5, animals had to associate an interruption of the aquarium air supply with food offering. Non-stressed zebrafish received an intraperitoneal injection of 100 mg/kg L-histidine, 10 mg/kg thioperamide or saline after training. Stressed animals received drug treatment and then were submitted to confinement stress for 1 h before the learning procedure. Time to approach the feeder was measured (in seconds and was considered to be indicative of learning. A decrease in time to approach the feeder was observed in the saline-treated group (D1 = 141.92 ± 13.57; D3 = 55 ± 13.54, indicating learning. A delay in learning of stressed animals treated with saline was observed (D1 = 217.5 ± 25.66. L-histidine facilitated learning in stressed (D1 = 118.68 ± 13.9; D2 = 45.88 ± 8.2 and non-stressed (D1 = 151.11 ± 19.20; D5 = 62 ± 14.68 animals. Thioperamide inhibited learning in non-stressed (D1 = 110.38 ± 9.49; D4 = 58.79 ± 16.83 and stressed animals (D1 = 167.3 ± 26.39; D5 = 172.15 ± 27.35. L-histidine prevented the increase in blood glucose after one session of confinement (L-histidine = 65.88 ± 4.50; control = 53 ± 3.50 mg/dL. These results suggest that the histaminergic system enhances learning and modulates stress responses in zebrafish.

  1. NAD+ Biosynthesis Ameliorates a Zebrafish Model of Muscular Dystrophy

    Science.gov (United States)

    Goody, Michelle F.; Kelly, Meghan W.; Reynolds, Christine J.; Khalil, Andre; Crawford, Bryan D.; Henry, Clarissa A.

    2012-01-01

    Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex– or integrin alpha7–deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction with integrin

  2. The endocannabinoid system and associative learning and memory in zebrafish.

    Science.gov (United States)

    Ruhl, Tim; Moesbauer, Kirstin; Oellers, Nadine; von der Emde, Gerhard

    2015-09-01

    In zebrafish the medial pallium of the dorsal telencephalon represents an amygdala homolog structure, which is crucially involved in emotional associative learning and memory. Similar to the mammalian amygdala, the medial pallium contains a high density of endocannabinoid receptor CB1. To elucidate the role of the zebrafish endocannabinoid system in associative learning, we tested the influence of acute and chronic administration of receptor agonists (THC, WIN55,212-2) and antagonists (Rimonabant, AM-281) on two different learning paradigms. In an appetitively motivated two-alternative choice paradigm, animals learned to associate a certain color with a food reward. In a second set-up, a fish shuttle-box, animals associated the onset of a light stimulus with the occurrence of a subsequent electric shock (avoidance conditioning). Once fish successfully had learned to solve these behavioral tasks, acute receptor activation or inactivation had no effect on memory retrieval, suggesting that established associative memories were stable and not alterable by the endocannabinoid system. In both learning tasks, chronic treatment with receptor antagonists improved acquisition learning, and additionally facilitated reversal learning during color discrimination. In contrast, chronic CB1 activation prevented aversively motivated acquisition learning, while different effects were found on appetitively motivated acquisition learning. While THC significantly improved behavioral performance, WIN55,212-2 significantly impaired color association. Our findings suggest that the zebrafish endocannabinoid system can modulate associative learning and memory. Stimulation of the CB1 receptor might play a more specific role in acquisition and storage of aversive learning and memory, while CB1 blocking induces general enhancement of cognitive functions. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Tools for automating the imaging of zebrafish larvae.

    Science.gov (United States)

    Pulak, Rock

    2016-03-01

    The VAST BioImager system is a set of tools developed for zebrafish researchers who require the collection of images from a large number of 2-7 dpf zebrafish larvae. The VAST BioImager automates larval handling, positioning and orientation tasks. Color images at about 10 μm resolution are collected from the on-board camera of the system. If images of greater resolution and detail are required, this system is mounted on an upright microscope, such as a confocal or fluorescence microscope, to utilize their capabilities. The system loads a larvae, positions it in view of the camera, determines orientation using pattern recognition analysis, and then more precisely positions to user-defined orientation for optimal imaging of any desired tissue or organ system. Multiple images of the same larva can be collected. The specific part of each larva and the desired orientation and position is identified by the researcher and an experiment defining the settings and a series of steps can be saved and repeated for imaging of subsequent larvae. The system captures images, then ejects and loads another larva from either a bulk reservoir, a well of a 96 well plate using the LP Sampler, or individually targeted larvae from a Petri dish or other container using the VAST Pipettor. Alternative manual protocols for handling larvae for image collection are tedious and time consuming. The VAST BioImager automates these steps to allow for greater throughput of assays and screens requiring high-content image collection of zebrafish larvae such as might be used in drug discovery and toxicology studies. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  4. NAD+ biosynthesis ameliorates a zebrafish model of muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Michelle F Goody

    Full Text Available Muscular dystrophies are common, currently incurable diseases. A subset of dystrophies result from genetic disruptions in complexes that attach muscle fibers to their surrounding extracellular matrix microenvironment. Cell-matrix adhesions are exquisite sensors of physiological conditions and mediate responses that allow cells to adapt to changing conditions. Thus, one approach towards finding targets for future therapeutic applications is to identify cell adhesion pathways that mediate these dynamic, adaptive responses in vivo. We find that nicotinamide riboside kinase 2b-mediated NAD+ biosynthesis, which functions as a small molecule agonist of muscle fiber-extracellular matrix adhesion, corrects dystrophic phenotypes in zebrafish lacking either a primary component of the dystrophin-glycoprotein complex or integrin alpha7. Exogenous NAD+ or a vitamin precursor to NAD+ reduces muscle fiber degeneration and results in significantly faster escape responses in dystrophic embryos. Overexpression of paxillin, a cell adhesion protein downstream of NAD+ in this novel cell adhesion pathway, reduces muscle degeneration in zebrafish with intact integrin receptors but does not improve motility. Activation of this pathway significantly increases organization of laminin, a major component of the extracellular matrix basement membrane. Our results indicate that the primary protective effects of NAD+ result from changes to the basement membrane, as a wild-type basement membrane is sufficient to increase resilience of dystrophic muscle fibers to damage. The surprising result that NAD+ supplementation ameliorates dystrophy in dystrophin-glycoprotein complex- or integrin alpha7-deficient zebrafish suggests the existence of an additional laminin receptor complex that anchors muscle fibers to the basement membrane. We find that integrin alpha6 participates in this pathway, but either integrin alpha7 or the dystrophin-glycoprotein complex is required in conjunction

  5. Studying disorders of vertebrate iron and heme metabolism using zebrafish.

    Science.gov (United States)

    van der Vorm, Lisa N; Paw, Barry H

    2017-01-01

    Iron is a crucial component of heme- and iron-sulfur clusters, involved in vital cellular functions such as oxygen transport, DNA synthesis, and respiration. Both excess and insufficient levels of iron and heme-precursors cause human disease, such as iron-deficiency anemia, hemochromatosis, and porphyrias. Hence, their levels must be tightly regulated, requiring a complex network of transporters and feedback mechanisms. The use of zebrafish to study these pathways and the underlying genetics offers many advantages, among others their optical transparency, ex-vivo development and high genetic and physiological conservations. This chapter first reviews well-established methods, such as large-scale mutagenesis screens that have led to the initial identification of a series of iron and heme transporters and the generation of a variety of mutant lines. Other widely used techniques are based on injection of RNA, including complementary morpholino knockdown and gene overexpression. In addition, we highlight several recently developed approaches, most notably endonuclease-based gene knockouts such as TALENs or the CRISPR/Cas9 system that have been used to study how loss of function can induce human disease phenocopies in zebrafish. Rescue by chemical complementation with iron-based compounds or small molecules can subsequently be used to confirm causality of the genetic defect for the observed phenotype. All together, zebrafish have proven to be - and will continue to serve as an ideal model to advance our understanding of the pathogenesis of human iron and heme-related diseases and to develop novel therapies to treat these conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Developmental Toxicity of Dextromethorphan in Zebrafish Embryos/Larvae

    Science.gov (United States)

    Xu, Zheng; Williams, Frederick E.; Liu, Ming-Cheh

    2012-01-01

    Dextromethorphan is widely used in over-the-counter cough and cold medications. Its efficacy and safety for infants and young children remains to be clarified. The present study was designed to use the zebrafish as a model to investigate the potential toxicity of dextromethorphan during the embryonic and larval development. Three sets of zebrafish embryos/larvae were exposed to dextromethorphan at 24 hours post fertilization (hpf), 48 hpf, and 72 hpf, respectively, during the embryonic/larval development. Compared with the 48 and 72 hpf exposure sets, the embryos/larvae in the 24 hpf exposure set showed much higher mortality rates which increased in a dose-dependent manner. Bradycardia and reduced blood flow were observed for the embryos/larvae treated with increasing concentrations of dextromethorphan. Morphological effects of dextromethorphan exposure, including yolk sac and cardiac edema, craniofacial malformation, lordosis, non-inflated swim bladder, and missing gill, were also more frequent and severe among zebrafish embryos/larvae exposed to dextromethorphan at 24 hpf. Whether the more frequent and severe developmental toxicity of dextromethorphan observed among the embryos/larvae in the 24 hpf exposure set, as compared with the 48 and 72 hpf exposure sets, is due to the developmental expression of the Phase I and Phase II enzymes involved in the metabolism of dextromethorphan remains to be clarified. A reverse transcription-polymerase chain reaction (RT-PCR) analysis, nevertheless, revealed developmental stage-dependent expression of mRNAs encoding SULT3 ST1 and SULT3 ST3, two enzymes previously shown to be capable of sulfating dextrorphan, an active metabolite of dextromethorphan. PMID:20737414

  7. Towards Developmental Models of Psychiatric Disorders in Zebrafish

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    William Howard James Norton

    2013-04-01

    Full Text Available Psychiatric disorders are a diverse set of diseases that affect all aspects of mental function including social interaction, thinking, feeling and mood. Although psychiatric disorders place a large economic burden on society, the drugs available to treat them are often palliative with variable efficacy and intolerable side-effects. The development of novel drugs has been hindered by a lack of knowledge about the etiology of these diseases. It is thus necessary to further investigate psychiatric disorders using a combination of human molecular genetics, gene-by-environment studies, in vitro pharmacological and biochemistry experiments, animal models and investigation of the non-biological basis of these diseases, such as environmental effects.Many psychiatric disorders, including autism spectrum disorder, attention-deficit/hyperactivity disorder, mental retardation and schizophrenia can be triggered by alterations to neural development. The zebrafish is a popular model for developmental biology that is increasingly used to study human disease. Recent work has extended this approach to examine psychiatric disorders as well. However, since psychiatric disorders affect complex mental functions that might be human specific, it is not possible to fully model them in fish. In this review, I will propose that the suitability of zebrafish for developmental studies, and the genetic tools available to manipulate them, provide a powerful model to study the roles of genes that are linked to psychiatric disorders during neural development. The relative speed and ease of conducting experiments in zebrafish can be used to address two areas of future research: the contribution of environmental factors to disease onset, and screening for novel therapeutic compounds.

  8. Skeletogenic fate of zebrafish cranial and trunk neural crest.

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    Erika Kague

    Full Text Available The neural crest (NC is a major contributor to the vertebrate craniofacial skeleton, detailed in model organisms through embryological and genetic approaches, most notably in chick and mouse. Despite many similarities between these rather distant species, there are also distinct differences in the contribution of the NC, particularly to the calvariae of the skull. Lack of information about other vertebrate groups precludes an understanding of the evolutionary significance of these differences. Study of zebrafish craniofacial development has contributed substantially to understanding of cartilage and bone formation in teleosts, but there is currently little information on NC contribution to the zebrafish skeleton. Here, we employ a two-transgene system based on Cre recombinase to genetically label NC in the zebrafish. We demonstrate NC contribution to cells in the cranial ganglia and peripheral nervous system known to be NC-derived, as well as to a subset of myocardial cells. The indelible labeling also enables us to determine NC contribution to late-forming bones, including the calvariae. We confirm suspected NC origin of cartilage and bones of the viscerocranium, including cartilages such as the hyosymplectic and its replacement bones (hymandibula and symplectic and membranous bones such as the opercle. The cleithrum develops at the border of NC and mesoderm, and as an ancestral component of the pectoral girdle was predicted to be a hybrid bone composed of both NC and mesoderm tissues. However, we find no evidence of a NC contribution to the cleithrum. Similarly, in the vault of the skull, the parietal bones and the caudal portion of the frontal bones show no evidence of NC contribution. We also determine a NC origin for caudal fin lepidotrichia; the presumption is that these are derived from trunk NC, demonstrating that these cells have the ability to form bone during normal vertebrate development.

  9. Using local chromatin structure to improve CRISPR/Cas9 efficiency in zebrafish.

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    Chen, Yunru; Zeng, Shiyang; Hu, Ruikun; Wang, Xiangxiu; Huang, Weilai; Liu, Jiangfang; Wang, Luying; Liu, Guifen; Cao, Ying; Zhang, Yong

    2017-01-01

    Although the CRISPR/Cas9 has been successfully applied in zebrafish, considerable variations in efficiency have been observed for different gRNAs. The workload and cost of zebrafish mutant screening is largely dependent on the mutation rate of injected embryos; therefore, selecting more effective gRNAs is especially important for zebrafish mutant construction. Besides the sequence features, local chromatin structures may have effects on CRISPR/Cas9 efficiency, which remain largely unexplored. In the only related study in zebrafish, nucleosome organization was not found to have an effect on CRISPR/Cas9 efficiency, which is inconsistent with recent studies in vitro and in mammalian cell lines. To understand the effects of local chromatin structure on CRISPR/Cas9 efficiency in zebrafish, we first determined that CRISPR/Cas9 introduced genome editing mainly before the dome stage. Based on this observation, we reanalyzed our published nucleosome organization profiles and generated chromatin accessibility profiles in the 256-cell and dome stages using ATAC-seq technology. Our study demonstrated that chromatin accessibility showed positive correlation with CRISPR/Cas9 efficiency, but we did not observe a clear correlation between nucleosome organization and CRISPR/Cas9 efficiency. We constructed an online database for zebrafish gRNA selection based on local chromatin structure features that could prove beneficial to zebrafish homozygous mutant construction via CRISPR/Cas9.

  10. Knocking Down Snrnp200 Initiates Demorphogenesis of Rod Photoreceptors in Zebrafish

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    Yuan Liu

    2015-01-01

    Full Text Available Purpose. The small nuclear ribonucleoprotein 200 kDa (SNRNP200 gene is a fundamental component for precursor message RNA (pre-mRNA splicing and has been implicated in the etiology of autosomal dominant retinitis pigmentosa (adRP. This study aims to determine the consequences of knocking down Snrnp200 in zebrafish. Methods. Expression of the Snrnp200 transcript in zebrafish was determined via whole mount in situ hybridization. Morpholino oligonucleotide (MO aiming to knock down the expression of Snrnp200 was injected into zebrafish embryos, followed by analyses of aberrant splicing and expression of the U4/U6-U5 tri-small nuclear ribonucleoproteins (snRNPs components and retina-specific transcripts. Systemic changes and retinal phenotypes were further characterized by histological study and immunofluorescence staining. Results. Snrnp200 was ubiquitously expressed in zebrafish. Knocking down Snrnp200 in zebrafish triggered aberrant splicing of the cbln1 gene, upregulation of other U4/U6-U5 tri-snRNP components, and downregulation of a panel of retina-specific transcripts. Systemic defects were found correlated with knockdown of Snrnp200 in zebrafish. Only demorphogenesis of rod photoreceptors was detected in the initial stage, mimicking the disease characteristics of RP. Conclusions. We conclude that knocking down Snrnp200 in zebrafish could alter regular splicing and expression of a panel of genes, which may eventually trigger rod defects.

  11. Comparison of Antemortem and Environmental Samples for Zebrafish Health Monitoring and Quarantine

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    Crim, Marcus J; Lawrence, Christian; Livingston, Robert S; Rakitin, Andrei; Hurley, Shane J; Riley, Lela K

    2017-01-01

    Molecular diagnostic assays offer both exquisite sensitivity and the ability to test a wide variety of sample types. Various types of environmental sample, such as detritus and concentrated water, might provide a useful adjunct to sentinels in routine zebrafish health monitoring. Similarly, antemortem sampling would be advantageous for expediting zebrafish quarantine, without euthanasia of valuable fish. We evaluated the detection of Mycobacterium chelonae, M. fortuitum, M. peregrinum, Pseudocapillaria tomentosa, and Pseudoloma neurophilia in zebrafish, detritus, pooled feces, and filter membranes after filtration of 1000-, 500-, and 150-mL water samples by real-time PCR analysis. Sensitivity varied according to sample type and pathogen, and environmental sampling was significantly more sensitive than zebrafish sampling for detecting Mycobacterium spp. but not for Pseudocapillaria neurophilia or Pseudoloma tomentosa. The results of these experiments provide strong evidence of the utility of multiple sample types for detecting pathogens according to each pathogen's life cycle and ecological niche within zebrafish systems. In a separate experiment, zebrafish subclinically infected with M. chelonae, M. marinum, Pleistophora hyphessobryconis, Pseudocapillaria tomentosa, or Pseudoloma neurophilia were pair-spawned and individually tested with subsets of embryos from each clutch that received no rinse, a fluidizing rinse, or were surface-disinfected with sodium hypochlorite. Frequently, one or both parents were subclinically infected with pathogen(s) that were not detected in any embryo subset. Therefore, negative results from embryo samples may not reflect the health status of the parent zebrafish. PMID:28724491

  12. Cardiac Ca2+ signalling in zebrafish: Translation of findings to man.

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    van Opbergen, Chantal J M; van der Voorn, Stephanie M; Vos, Marc A; de Boer, Teun P; van Veen, Toon A B

    2018-05-07

    Sudden cardiac death is a leading cause of death worldwide, mainly caused by highly disturbed electrical activation patterns in the heart. Currently, murine models are the most popular model to study underlying molecular mechanisms of inherited or acquired cardiac electrical abnormalities, although the numerous electrophysiological discrepancies between mouse and human raise the question whether mice are the optimal model to study cardiac rhythm disorders. Recently it has been uncovered that the zebrafish cardiac electrophysiology seems surprisingly similar to the human heart, mainly because the zebrafish AP contains a clear plateau phase and ECG characteristics show alignment with the human ECG. Although, before using zebrafish as a model to study cardiac arrhythmogenesis, however, it is very important to gain a better insight into the electrophysiological characteristics of the zebrafish heart. In this review we outline the electrophysiological machinery of the zebrafish cardiomyocytes, with a special focus on the intracellular Ca 2+ dynamics and excitation-contraction coupling. We debate the potential of zebrafish as a model to study human cardiovascular diseases and postulate steps to employ zebrafish into a more 'humanized' model. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Innovative Disease Model: Zebrafish as an In Vivo Platform for Intestinal Disorder and Tumors

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    Jeng-Wei Lu

    2017-09-01

    Full Text Available Colorectal cancer (CRC is one of the world’s most common cancers and is the second leading cause of cancer deaths, causing more than 50,000 estimated deaths each year. Several risk factors are highly associated with CRC, including being overweight, eating a diet high in red meat and over-processed meat, having a history of inflammatory bowel disease, and smoking. Previous zebrafish studies have demonstrated that multiple oncogenes and tumor suppressor genes can be regulated through genetic or epigenetic alterations. Zebrafish research has also revealed that the activation of carcinogenesis-associated signal pathways plays an important role in CRC. The biology of cancer, intestinal disorders caused by carcinogens, and the morphological patterns of tumors have been found to be highly similar between zebrafish and humans. Therefore, the zebrafish has become an important animal model for translational medical research. Several zebrafish models have been developed to elucidate the characteristics of gastrointestinal diseases. This review article focuses on zebrafish models that have been used to study human intestinal disorders and tumors, including models involving mutant and transgenic fish. We also report on xenograft models and chemically-induced enterocolitis. This review demonstrates that excellent zebrafish models can provide novel insights into the pathogenesis of gastrointestinal diseases and help facilitate the evaluation of novel anti-tumor drugs.

  14. BMP signaling modulates hepcidin expression in zebrafish embryos independent of hemojuvelin.

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    Yann Gibert

    2011-01-01

    Full Text Available Hemojuvelin (Hjv, a member of the repulsive-guidance molecule (RGM family, upregulates transcription of the iron regulatory hormone hepcidin by activating the bone morphogenetic protein (BMP signaling pathway in mammalian cells. Mammalian models have identified furin, neogenin, and matriptase-2 as modifiers of Hjv's function. Using the zebrafish model, we evaluated the effects of hjv and its interacting proteins on hepcidin expression during embryonic development. We found that hjv is strongly expressed in the notochord and somites of the zebrafish embryo and that morpholino knockdown of hjv impaired the development of these structures. Knockdown of hjv or other hjv-related genes, including zebrafish orthologs of furin or neogenin, however, failed to decrease hepcidin expression relative to liver size. In contrast, overexpression of bmp2b or knockdown of matriptase-2 enhanced the intensity and extent of hepcidin expression in zebrafish embryos, but this occurred in an hjv-independent manner. Furthermore, we demonstrated that zebrafish hjv can activate the human hepcidin promoter and enhance BMP responsive gene expression in vitro, but is expressed at low levels in the zebrafish embryonic liver. Taken together, these data support an alternative mechanism for hepcidin regulation during zebrafish embryonic development, which is independent of hjv.

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

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    Young-Sun Moon

    2016-10-01

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

  16. The essential role of endogenous ghrelin in growth hormone expression during zebrafish adenohypophysis development.

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    Li, Xi; He, Jiangyan; Hu, Wei; Yin, Zhan

    2009-06-01

    Ghrelin, a multifunctional hormone, including potent GH stimulation activity, has been suggested to be important during embryonic development. Expression of ghrelin has been confirmed in the zebrafish pancreas during embryonic stages. Interfering with ghrelin function using two specific antisense morpholino oligonucleotides causes defects during zebrafish embryonic development. In ghrelin morphants the expression of GH was abolished in zebrafish somatotropes, whereas the expression patterns of the other key molecules involved in hypothalamic-pituitary development and distinct pituitary hormones genes remain largely intact at the appropriate time during zebrafish adenohypophysis development. Effective rescue of the ghrelin morphants with exogenous ghrelin mRNA showed that the correct gene had been targeted. Moreover, by analyzing the efficiencies of the ghrelin morphants rescue experiments with various forms of exogenous mutant ghrelin mRNAs, we also demonstrated the essentiality of the form acyl-ghrelin on GH stimulation during zebrafish adenohypophysis development. Our in vivo experiments, for the first time, also provided evidence of the existence of functional obestatin in the C-terminal part of zebrafish proghrelin peptides. Our research here has demonstrated that zebrafish is a unique model for functional studies of endogenous ghrelin, especially during embryonic development.

  17. A multi-scale model for correlation in B cell VDJ usage of zebrafish

    International Nuclear Information System (INIS)

    Pan, Keyao; Deem, Michael W

    2011-01-01

    The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment

  18. A multi-scale model for correlation in B cell VDJ usage of zebrafish

    Science.gov (United States)

    Pan, Keyao; Deem, Michael W.

    2011-10-01

    The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment.

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

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    Anastasia A. Batrakova

    2015-11-01

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

  20. Discriminating Different Cancer Cells Using a Zebrafish in Vivo Assay

    International Nuclear Information System (INIS)

    Moshal, Karni S.; Ferri-Lagneau, Karine F.; Haider, Jamil; Pardhanani, Pooja; Leung, TinChung

    2011-01-01

    Despite the expanded understanding of tumor angiogenesis phenomenon and how it impacts cancer treatment outcomes, we have yet to develop a robust assay that can quickly, easily, and quantitatively measure tumor-induced angiogenesis. Since the zebrafish/tumor xenograft represents an emerging tool in this regard, the present study strives to capitalize on the ease, effectiveness, and the adaptability of this model to quantify tumor angiogenesis. In order to test a range of responses, we chose two different tumorigenic cell lines, the human non-small cell lung carcinoma (H1299) and the mouse lung adenocarcinoma (CL13). Non-tumorigenic 3T3-L1 cells served as negative control. The cells were grafted near to the perivitelline space of the zebrafish embryos and the angiogenic response was analyzed using whole-mount alkaline phosphatase (AP) vessel staining and fluorescence microscopy. Angiogenic activity was scored based on the length and number of the newly formed ectopic vessels and the percentage of embryos with ectopic vessels. At 2 day-post-implantation, we detected a significant increase in the length and number of ectopic vessels with H1299 cell implantation compared to CL13 cell transplantation, both are higher than 3T3-L1 control. We also observed a significantly higher percentage of embryos with ectopic vessels with H1299 and CL13 transplantation compared to the 3T3-L1 control, but this parameter is not as robust and reliable as measuring the length and number of ectopic vessels. Furthermore, the systemic exposure of zebrafish embryos to an anti-angiogenesis drug (PTK 787, inhibitor of vascular endothelial growth factor receptor tyrosine kinase) inhibited tumor-induced angiogenesis, suggesting that the assay can be used to evaluate anti-angiogenic drugs. This study implicates the feasibility of using zebrafish xenotransplantation to perform quantitative measurement of the angiogenic activity of cancer cells which can be further extended to measure cancer cell

  1. The zebrafish progranulin gene family and antisense transcripts

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    Baranowski David

    2005-11-01

    Full Text Available Abstract Background Progranulin is an epithelial tissue growth factor (also known as proepithelin, acrogranin and PC-cell-derived growth factor that has been implicated in development, wound healing and in the progression of many cancers. The single mammalian progranulin gene encodes a glycoprotein precursor consisting of seven and one half tandemly repeated non-identical copies of the cystine-rich granulin motif. A genome-wide duplication event hypothesized to have occurred at the base of the teleost radiation predicts that mammalian progranulin may be represented by two co-orthologues in zebrafish. Results The cDNAs encoding two zebrafish granulin precursors, progranulins-A and -B, were characterized and found to contain 10 and 9 copies of the granulin motif respectively. The cDNAs and genes encoding the two forms of granulin, progranulins-1 and -2, were also cloned and sequenced. Both latter peptides were found to be encoded by precursors with a simplified architecture consisting of one and one half copies of the granulin motif. A cDNA encoding a chimeric progranulin which likely arises through the mechanism of trans-splicing between grn1 and grn2 was also characterized. A non-coding RNA gene with antisense complementarity to both grn1 and grn2 was identified which may have functional implications with respect to gene dosage, as well as in restricting the formation of the chimeric form of progranulin. Chromosomal localization of the four progranulin (grn genes reveals syntenic conservation for grna only, suggesting that it is the true orthologue of mammalian grn. RT-PCR and whole-mount in situ hybridization analysis of zebrafish grns during development reveals that combined expression of grna and grnb, but not grn1 and grn2, recapitulate many of the expression patterns observed for the murine counterpart. This includes maternal deposition, widespread central nervous system distribution and specific localization within the epithelial

  2. Effects of probiotic administration on zebrafish development and reproduction.

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    Carnevali, O; Avella, M A; Gioacchini, G

    2013-07-01

    As the consumption of probiotics increases worldwide, scientists focus on identifying bacterial strains able to improve human life quality and evidence the biological pathways affected by probiotic treatment. In this review, some recent observations on the effects of changes of microbiota on zebrafish metabolism were discussed. In addition, the effects of Lactobacillus rhamnosus - a component of the human gut microflora - as a diet supplement on Danio rerio were presented. When administered chronically, L. rhamnosus may affect larval development and the physiology of reproductive system in the zebrafish model. It was hypothesized exogenous L. rhamnosus accelerates larval growth and backbone development by acting on insulin-like growth factors-I (igfI) and -II (igfII), peroxisome proliferator activated receptors-α and -β, (pparα,β) vitamin D receptor-α (vdrα) and retinoic acid receptor-γ (rarγ). Gonadal differentiation was anticipated at 6weeks together with a higher expression of gnrh3 at the larval stage when L. rhamnosus was administered throughout development. Moreover, brood stock alimented with a L. rhamnosus-supplemented diet showed better reproductive performances as per follicles development, ovulated oocytes quantification and embryos quality. A plausible involvement of factors such as leptin, and kiss1 and 2 in the improvements was concluded. The observations made on the physiology of female reproduction were correlated with the gene expression of a gigantic number of factors as the aromatase cytochrome p 19 (cyp19a), the vitellogenin (vtg) and the α isoform of the E2 receptor (erα), luteinizing hormone receptor (lhr), 20-β hydroxysteroid dehydrogenase (20β-hsd), membrane progesterone receptors α and β, cyclin B, activinβA1, smad2, transforming growth factor β1 (tgfβ1), growth differentiation factor9 (gdf9) and bone morphogenetic protein15 (bmp15.) A model in which the exogenous L. rhamnosus in the digestive tract of zebrafish from the

  3. Scopolamine methylbromide mitigates radiation induced damage and lethality in zebrafish

    International Nuclear Information System (INIS)

    Shrivastava, Nitisha; Joshi, Jayadev; Ghosh, Subhajit; Dimri, Manali; Prem Kumar, Indracanti; Sehgal, Neeta

    2014-01-01

    In view of the strategic importance radiation countermeasures hold, the present study was undertaken to screen a collection of small molecule clinical compounds for possible radioprotective action using zebrafish as a model system. Preliminary screening in developing zebrafish embryos (24 hour post fertilization, (hpf)) using damage manifestations and survival as end point identified scopolamine methylbromide (SMB), a muscarinic receptor antagonist, as a potential radiomitigator. It was found to be optimal (60% survival advantage after 6 th post irradiation day) at a dose of 80 μM when added 3 h post 20 Gy exposure. Mechanistic studies suggested that SMB though exhibited no significant antioxidant potential, but was found to limit radiation induced apoptosis (pre G1 population) quantified through flow cytometry (6 and 5% reduction after 8 or 24 h after treatments) and annexin V staining (8% reduction). Further, quantitative analysis, using caspase 3 assay, revealed a 2.46 fold increase in apoptosis in irradiated group and treatment of irradiated zebrafish embryos with SMB led to a significant reduction in global apoptosis (1.7 fold; p<0.05) when compared to irradiated group. In silico studies based on structural and functional similarity with known radioprotectors suggested similarities with atropine, a known anti-inflammatory agent with muscarinic antagonism and radioprotective potential. In view of this SMB was tested, in silico, for possible anti-inflammatory action. Molecular docking studies revealed that SMB interacts (B.E-8.0 Kcal/mole) with cycloxygenase-2 (COX-2). In lieu of this, anti-inflammation activity was assessed through ChIN (chemically induced inflammation) method in 3 dpf (days post fertilization) embryos and SMB was found to significantly inhibit inflammation at all doses studied from 20-200 μM at 3 and 6 hpi (hours post inflammation). Overall the result suggests that scopolamine methylbromide mitigates radiation induced injury and lethality in

  4. Discriminating Different Cancer Cells Using a Zebrafish in Vivo Assay

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    Pooja Pardhanani

    2011-10-01

    Full Text Available Despite the expanded understanding of tumor angiogenesis phenomenon and how it impacts cancer treatment outcomes, we have yet to develop a robust assay that can quickly, easily, and quantitatively measure tumor-induced angiogenesis. Since the zebrafish/tumor xenograft represents an emerging tool in this regard, the present study strives to capitalize on the ease, effectiveness, and the adaptability of this model to quantify tumor angiogenesis. In order to test a range of responses, we chose two different tumorigenic cell lines, the human non-small cell lung carcinoma (H1299 and the mouse lung adenocarcinoma (CL13. Non-tumorigenic 3T3-L1 cells served as negative control. The cells were grafted near to the perivitelline space of the zebrafish embryos and the angiogenic response was analyzed using whole-mount alkaline phosphatase (AP vessel staining and fluorescence microscopy. Angiogenic activity was scored based on the length and number of the newly formed ectopic vessels and the percentage of embryos with ectopic vessels. At 2 day-post-implantation, we detected a significant increase in the length and number of ectopic vessels with H1299 cell implantation compared to CL13 cell transplantation, both are higher than 3T3-L1 control. We also observed a significantly higher percentage of embryos with ectopic vessels with H1299 and CL13 transplantation compared to the 3T3-L1 control, but this parameter is not as robust and reliable as measuring the length and number of ectopic vessels. Furthermore, the systemic exposure of zebrafish embryos to an anti-angiogenesis drug (PTK 787, inhibitor of vascular endothelial growth factor receptor tyrosine kinase inhibited tumor-induced angiogenesis, suggesting that the assay can be used to evaluate anti-angiogenic drugs. This study implicates the feasibility of using zebrafish xenotransplantation to perform quantitative measurement of the angiogenic activity of cancer cells which can be further extended to

  5. Dynamic neuroanatomy at subcellular resolution in the zebrafish.

    Science.gov (United States)

    Faucherre, Adèle; López-Schier, Hernán

    2014-01-01

    Genetic means to visualize and manipulate neuronal circuits in the intact animal have revolutionized neurobiology. "Dynamic neuroanatomy" defines a range of approaches aimed at quantifying the architecture or subcellular organization of neurons over time during their development, regeneration, or degeneration. A general feature of these approaches is their reliance on the optical isolation of defined neurons in toto by genetically expressing markers in one or few cells. Here we use the afferent neurons of the lateral line as an example to describe a simple method for the dynamic neuroanatomical study of axon terminals in the zebrafish by laser-scanning confocal microscopy.

  6. Diversity in cell motility reveals the dynamic nature of the formation of zebrafish taste sensory organs.

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    Soulika, Marina; Kaushik, Anna-Lila; Mathieu, Benjamin; Lourenço, Raquel; Komisarczuk, Anna Z; Romano, Sebastian Alejo; Jouary, Adrien; Lardennois, Alicia; Tissot, Nicolas; Okada, Shinji; Abe, Keiko; Becker, Thomas S; Kapsimali, Marika

    2016-06-01

    Taste buds are sensory organs in jawed vertebrates, composed of distinct cell types that detect and transduce specific taste qualities. Taste bud cells differentiate from oropharyngeal epithelial progenitors, which are localized mainly in proximity to the forming organs. Despite recent progress in elucidating the molecular interactions required for taste bud cell development and function, the cell behavior underlying the organ assembly is poorly defined. Here, we used time-lapse imaging to observe the formation of taste buds in live zebrafish larvae. We found that tg(fgf8a.dr17)-expressing cells form taste buds and get rearranged within the forming organs. In addition, differentiating cells move from the epithelium to the forming organs and can be displaced between developing organs. During organ formation, tg(fgf8a.dr17) and type II taste bud cells are displaced in random, directed or confined mode relative to the taste bud they join or by which they are maintained. Finally, ascl1a activity in the 5-HT/type III cell is required to direct and maintain tg(fgf8a.dr17)-expressing cells into the taste bud. We propose that diversity in displacement modes of differentiating cells acts as a key mechanism for the highly dynamic process of taste bud assembly. © 2016. Published by The Company of Biologists Ltd.

  7. Toxic effects of silica nanoparticles on zebrafish embryos and larvae.

    Directory of Open Access Journals (Sweden)

    Junchao Duan

    Full Text Available Silica nanoparticles (SiNPs have been widely used in biomedical and biotechnological applications. Environmental exposure to nanomaterials is inevitable as they become part of our daily life. Therefore, it is necessary to investigate the possible toxic effects of SiNPs exposure. In this study, zebrafish embryos were treated with SiNPs (25, 50, 100, 200 µg/mL during 4-96 hours post fertilization (hpf. Mortality, hatching rate, malformation and whole-embryo cellular death were detected. We also measured the larval behavior to analyze whether SiNPs had adverse effects on larvae locomotor activity. The results showed that as the exposure dosages increasing, the hatching rate of zebrafish embryos was decreased while the mortality and cell death were increased. Exposure to SiNPs caused embryonic malformations, including pericardial edema, yolk sac edema, tail and head malformation. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lower dose (25 and 50 µg/mL SiNPs produced substantial hyperactivity while the higher doses (100 and 200 µg/mL SiNPs elicited remarkably hypoactivity in dark periods. In summary, our data indicated that SiNPs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior.

  8. Specific nanotoxicity of graphene oxide during zebrafish embryogenesis.

    Science.gov (United States)

    Chen, Yuming; Hu, Xiangang; Sun, Jing; Zhou, Qixing

    2016-01-01

    Graphene oxide (GO) has shown great potential for biological, medical, energy and electronic applications. As a consequence of these diverse applications, GO release into the ecosystem is inevitable; however, the corresponding risks are largely unknown, particularly with respect to the critical period of embryogenesis. This study revealed that GO adhered to and enveloped the chorion of zebrafish embryos mainly via hydroxyl group interactions, blocked the pore canals of the chorionic membrane, and caused marked hypoxia and hatching delay. Furthermore, GO spontaneously penetrated the chorion, entered the embryo via endocytosis, damaged the mitochondria and primarily translocated to the eye, heart and yolk sac regions, which are involved in the circulatory system of zebrafish. In these organs, GO induced excessive generation of reactive oxygen species and increased oxidative stress, DNA damage and apoptosis. Graphene oxide also induced developmental malformation of the eye, cardiac/yolk sac edema, tail flexure and heart rate reduction. In contrast to the common dose-effect relationships of nanoparticles, the adverse effects of GO on heart rate and tail/spinal cord flexure increased and then decreased as the GO concentration increased. These findings emphasize the specific adverse effects of GO on embryogenesis and highlight the potential ecological and health risks of GO.

  9. Developmental lead exposure causes startle response deficits in zebrafish.

    Science.gov (United States)

    Rice, Clinton; Ghorai, Jugal K; Zalewski, Kathryn; Weber, Daniel N

    2011-10-01

    Lead (Pb(2+)) exposure continues to be an important concern for fish populations. Research is required to assess the long-term behavioral effects of low-level concentrations of Pb(2+) and the physiological mechanisms that control those behaviors. Newly fertilized zebrafish embryos (max) and escape time. With increasing exposure concentrations, a larger number of larvae failed to respond to even the initial tap and, for those that did respond, ceased responding earlier than control larvae. These differences were more pronounced at a frequency of 4 taps/s. (2) Response to a visual stimulus: Fish, exposed as embryos (2-24 hpf) to Pb(2+) (0-10 μM) were tested as adults under low light conditions (≈ 60 μW/m(2)) for visual responses to a rotating black bar. Visual responses were significantly degraded at Pb(2+) concentrations of 30 nM. These data suggest that zebrafish are viable models for short- and long-term sensorimotor deficits induced by acute, low-level developmental Pb(2+) exposures. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Transcriptome analysis of severe hypoxic stress during development in zebrafish

    Directory of Open Access Journals (Sweden)

    I.G. Woods

    2015-12-01

    Full Text Available Hypoxia causes critical cellular injury both in early human development and in adulthood, leading to cerebral palsy, stroke, and myocardial infarction. Interestingly, a remarkable phenomenon known as hypoxic preconditioning arises when a brief hypoxia exposure protects target organs against subsequent, severe hypoxia. Although hypoxic preconditioning has been demonstrated in several model organisms and tissues including the heart and brain, its molecular mechanisms remain poorly understood. Accordingly, we used embryonic and larval zebrafish to develop a novel vertebrate model for hypoxic preconditioning, and used this model to identify conserved hypoxia-regulated transcripts for further functional study as published in Manchenkov et al. (2015 in G3: Genes|Genomes|Genetics. In this Brief article, we provide extensive annotation for the most strongly hypoxia-regulated genes in zebrafish, including their human orthologs, and describe in detail the methods used to identify, filter, and annotate hypoxia-regulated transcripts for downstream functional and bioinformatic assays using the source data provided in Gene Expression Omnibus Accession GSE68473.

  11. Muscle dysfunction in a zebrafish model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Widrick, Jeffrey J; Alexander, Matthew S; Sanchez, Benjamin; Gibbs, Devin E; Kawahara, Genri; Beggs, Alan H; Kunkel, Louis M

    2016-11-01

    Sapje zebrafish lack the protein dystrophin and are the smallest vertebrate model of Duchenne muscular dystrophy (DMD). Their small size makes them ideal for large-scale drug discovery screens. However, the extent that sapje mimic the muscle dysfunction of higher vertebrate models of DMD is unclear. We used an optical birefringence assay to differentiate affected dystrophic sapje larvae from their unaffected siblings and then studied trunk muscle contractility at 4-7 days postfertilization. Preparation cross-sectional area (CSA) was similar for affected and unaffected larvae, yet tetanic forces of affected preparations were only 30-60% of normal. ANCOVA indicated that the linear relationship observed between tetanic force and CSA for unaffected preparations was absent in the affected population. Consequently, the average force/CSA of affected larvae was depressed 30-70%. Disproportionate reductions in twitch vs. tetanic force, and a slowing of twitch tension development and relaxation, indicated that the myofibrillar disorganization evident in the birefringence assay could not explain the entire force loss. Single eccentric contractions, in which activated preparations were lengthened 5-10%, resulted in tetanic force deficits in both groups of larvae. However, deficits of affected preparations were three- to fivefold greater at all strains and ages, even after accounting for any recovery. Based on these functional assessments, we conclude that the sapje mutant zebrafish is a phenotypically severe model of DMD. The severe contractile deficits of sapje larvae represent novel physiological endpoints for therapeutic drug screening. Copyright © 2016 the American Physiological Society.

  12. Effects of uranium on the metabolism of zebrafish, Danio rerio

    International Nuclear Information System (INIS)

    Augustine, Starrlight; Gagnaire, Béatrice; Adam-Guillermin, Christelle; Kooijman, Sebastiaan A.L.M.

    2012-01-01

    The increasing demand for nuclear energy results in heightened levels of uranium (U) in aquatic systems which present a potential health hazard to resident organisms. The aim of this study was to mechanistically assess how chronic exposure to environmentally relevant concentrations of U perturbs the complex interplay between feeding, growth, maintenance, maturation and reproduction throughout the life-cycle of an individual. To this end we analysed literature-based and original zebrafish toxicity data within a same mass and energy balancing conceptual framework. U was found to increase somatic maintenance leading to inhibition of spawning as well as increase hazard rate and costs for growth during the early life stages. The fish's initial conditions and elimination through reproduction greatly affected toxico-kinetics and effects. We demonstrate that growth and reproduction should be measured on specific individuals since mean values were hardly interpretable. The mean food level differed between experiments, conditions and individuals. This last ‘detail’ contributed substantially to the observed variability by its combined effect on metabolism, toxic effects and toxico-kinetics. The significance of this work is that we address exactly how these issues are related and derive conclusions which are independent of experimental protocol and coherent with a very large body of literature on zebrafish eco-physiology.

  13. Transformation of tributyltin in zebrafish eleutheroembryos (Danio rerio).

    Science.gov (United States)

    Borges, Aline Rocha; López-Serrano Oliver, Ana; Gallego-Gallegos, Mercedes; Muñoz-Olivas, Riansares; Rodrigues Vale, Maria Goreti; Cámara, Carmen

    2014-12-01

    Organotin compounds are highly versatile group of organometallic chemicals used in industrial and agricultural applications. Their endocrine-disrupting effects are well known and their extensive uses as biocide materials, e.g., in antifouling paints, for many years have led to serious environmental problems. So far, attention has mainly been given to tributyltin pollution in water, sediments, and marine organisms because of its highly toxic effects and high accumulation levels at very low concentrations. In this study, we will focus on the conversion of tributyltin after it is absorbed by zebrafish eleutheroembryos, presented here as an alternative model to adult fish for describing bioconcentration. A simplified analytical extraction procedure based on the use of an assisted ultrasonic probe and derivatization by ethylation, followed by gas chromatography with a flame photometric detector (GC-FPD) is proposed. This classical methodology for organotin determination has been validated by inductively coupled plasma mass spectrometry (ICP-MS) and Zeeman graphite furnace atomic absorption spectrometry (ZGF-AAS) in terms of total tin content. The speciation analysis results show that zebrafish eleutheroembryos absorb high amounts of tributyltin and convert it into monobutyltin and likely in inorganic tin.

  14. Effects of uranium on the metabolism of zebrafish, Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Augustine, Starrlight, E-mail: starr-light.augustine@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Gagnaire, Beatrice, E-mail: beatrice.gagnaire@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.fr [Laboratory of Radionuclide Ecotoxicology, PRP-ENV/SERIS/LECO, Institute of Radioprotection and Nuclear Safety (IRSN), Caradache, Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Kooijman, Sebastiaan A.L.M., E-mail: bas.kooijman@vu.nl [Department of Theoretical Biology, Vrije Universiteit, de Boelelaan 1087, 1081 HV Amsterdam (Netherlands)

    2012-08-15

    The increasing demand for nuclear energy results in heightened levels of uranium (U) in aquatic systems which present a potential health hazard to resident organisms. The aim of this study was to mechanistically assess how chronic exposure to environmentally relevant concentrations of U perturbs the complex interplay between feeding, growth, maintenance, maturation and reproduction throughout the life-cycle of an individual. To this end we analysed literature-based and original zebrafish toxicity data within a same mass and energy balancing conceptual framework. U was found to increase somatic maintenance leading to inhibition of spawning as well as increase hazard rate and costs for growth during the early life stages. The fish's initial conditions and elimination through reproduction greatly affected toxico-kinetics and effects. We demonstrate that growth and reproduction should be measured on specific individuals since mean values were hardly interpretable. The mean food level differed between experiments, conditions and individuals. This last 'detail' contributed substantially to the observed variability by its combined effect on metabolism, toxic effects and toxico-kinetics. The significance of this work is that we address exactly how these issues are related and derive conclusions which are independent of experimental protocol and coherent with a very large body of literature on zebrafish eco-physiology.

  15. Developmental defects in zebrafish for classification of EGF pathway inhibitors

    International Nuclear Information System (INIS)

    Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc

    2014-01-01

    One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors

  16. Developmental defects in zebrafish for classification of EGF pathway inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc, E-mail: m.muller@ulg.ac.be

    2014-01-15

    One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors.

  17. Generation and characterization of Kctd15 mutations in zebrafish.

    Directory of Open Access Journals (Sweden)

    Alison Heffer

    Full Text Available Potassium channel tetramerization domain containing 15 (Kctd15 was previously found to have a role in early neural crest (NC patterning, specifically delimiting the region where NC markers are expressed via repression of transcription factor AP-2a and inhibition of Wnt signaling. We used transcription activator-like effector nucleases (TALENs to generate null mutations in zebrafish kctd15a and kctd15b paralogs to study the in vivo role of Kctd15. We found that while deletions producing frame-shift mutations in each paralog showed no apparent phenotype, kctd15a/b double mutant zebrafish are smaller in size and show several phenotypes including some affecting the NC, such as expansion of the early NC domain, increased pigmentation, and craniofacial defects. Both melanophore and xanthophore pigment cell numbers and early markers are up-regulated in the double mutants. While we find no embryonic craniofacial defects, adult mutants have a deformed maxillary segment and missing barbels. By confocal imaging of mutant larval brains we found that the torus lateralis (TLa, a region implicated in gustatory networks in other fish, is absent. Ablation of this brain tissue in wild type larvae mimics some aspects of the mutant growth phenotype. Thus kctd15 mutants show deficits in the development of both neural crest derivatives, and specific regions within the central nervous system, leading to a strong reduction in normal growth rates.

  18. Temporally-controlled site-specific recombination in zebrafish.

    Directory of Open Access Journals (Sweden)

    Stefan Hans

    Full Text Available Conventional use of the site-specific recombinase Cre is a powerful technology in mouse, but almost absent in other vertebrate model organisms. In zebrafish, Cre-mediated recombination efficiency was previously very low. Here we show that using transposon-mediated transgenesis, Cre is in fact highly efficient in this organism. Furthermore, temporal control of recombination can be achieved by using the ligand-inducible CreER(T2. Site-specific recombination only occurs upon administration of the drug tamoxifen (TAM or its active metabolite, 4-hydroxy-tamoxifen (4-OHT. Cre-mediated recombination is detectable already 4 or 2 hours after administration of TAM or 4-OHT, demonstrating fast recombination kinetics. In addition, low doses of TAM allow mosaic labeling of single cells. Combined, our results show that conditional Cre/lox will be a valuable tool for both, embryonic and adult zebrafish studies. Furthermore, single copy insertion transgenesis of Cre/lox constructs suggest a strategy suitable also for other organisms.

  19. Ftr82 Is Critical for Vascular Patterning during Zebrafish Development

    Directory of Open Access Journals (Sweden)

    Hsueh-Wei Chang

    2017-01-01

    Full Text Available Cellular components and signaling pathways are required for the proper growth of blood vessels. Here, we report for the first time that a teleost-specific gene ftr82 (finTRIM family, member 82 plays a critical role in vasculature during zebrafish development. To date, there has been no description of tripartite motif proteins (TRIM in vascular development, and the role of ftr82 is unknown. In this study, we found that ftr82 mRNA is expressed during the development of vessels, and loss of ftr82 by morpholino (MO knockdown impairs the growth of intersegmental vessels (ISV and caudal vein plexus (CVP, suggesting that ftr82 plays a critical role in promoting ISV and CVP growth. We showed the specificity of ftr82 MO by analyzing ftr82 expression products and expressing ftr82 mRNA to rescue ftr82 morphants. We further showed that the knockdown of ftr82 reduced ISV cell numbers, suggesting that the growth impairment of vessels is likely due to a decrease of cell proliferation and migration, but not cell death. In addition, loss of ftr82 affects the expression of vascular markers, which is consistent with the defect of vascular growth. Finally, we showed that ftr82 likely interacts with vascular endothelial growth factor (VEGF and Notch signaling. Together, we identify teleost-specific ftr82 as a vascular gene that plays an important role for vascular development in zebrafish.

  20. Mechanisms of social buffering of fear in zebrafish.

    Science.gov (United States)

    Faustino, Ana I; Tacão-Monteiro, André; Oliveira, Rui F

    2017-03-31

    Some humans thrive whereas others resign when exposed to threatening situations throughout life. Social support has been identified as an important modulator of these discrepancies in human behaviour, and other social animals also exhibit phenomena in which individuals recover better from aversive events when conspecifics are present - aka social buffering. Here we studied social buffering in zebrafish, by exposing focal fish to an aversive stimulus (alarm substance - AS) either in the absence or presence of conspecific cues. When exposed to AS in the presence of both olfactory (shoal water) and visual (sight of shoal) conspecific cues, focal fish exhibited a lower fear response than when tested alone, demonstrating social buffering in zebrafish. When separately testing each cue's effectiveness, we verified that the visual cue was more effective than the olfactory in reducing freezing in a persistent threat scenario. Finally, we verified that social buffering was independent of shoal size and coincided with a distinct pattern of co-activation of brain regions known to be involved in mammalian social buffering. Thus, this study suggests a shared evolutionary origin for social buffering in vertebrates, bringing new evidence on the behavioural, sensory and neural mechanisms underlying this phenomenon.

  1. Dcc regulates asymmetric outgrowth of forebrain neurons in zebrafish.

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    Jingxia Gao

    Full Text Available The guidance receptor DCC (deleted in colorectal cancer ortholog UNC-40 regulates neuronal asymmetry development in Caenorhabditis elegans, but it is not known whether DCC plays a role in the specification of neuronal polarity in vertebrates. To examine the roles of DCC in neuronal asymmetry regulation in vertebrates, we studied zebrafish anterior dorsal telencephalon (ADt neuronal axons. We generated transgenic zebrafish animals expressing the photo-convertible fluorescent protein Kaede in ADt neurons and then photo-converted Kaede to label specifically the ADt neuron axons. We found that ADt axons normally project ventrally. Knock down of Dcc function by injecting antisense morpholino oligonucleotides caused the ADt neurons to project axons dorsally. To examine the axon projection pattern of individual ADt neurons, we labeled single ADt neurons using a forebrain-specific promoter to drive fluorescent protein expression. We found that individual ADt neurons projected axons dorsally or formed multiple processes after morpholino knock down of Dcc function. We further found that knock down of the Dcc ligand, Netrin1, also caused ADt neurons to project axons dorsally. Knockdown of Neogenin1, a guidance receptor closely related to Dcc, enhanced the formation of aberrant dorsal axons in embryos injected with Dcc morpholino. These experiments provide the first evidence that Dcc regulates polarized axon initiation and asymmetric outgrowth of forebrain neurons in vertebrates.

  2. The hydrodynamics of predator-prey interactions in zebrafish

    Science.gov (United States)

    McHenry, Matthew; Soto, Alberto; Carrillo, Andres; Byron, Margaret

    2017-11-01

    Hydrodynamics govern the behavior of fishes when they operate as predators or prey. In addition to the role of fluid forces in propulsion, fishes relay on flow stimuli to sense a predatory threat and to localize palatable prey. We have performed a series of experiments on zebrafish (Danio rerio) that aim to resolve the major factors that determine whether prey survive an encounter with a predator. Zebrafish serve as a model system in this pursuit because the adults prey on larvae of the same species and the larvae are often successful in evading the attacks of the adults. We use a combination of theoretical and experimental approaches to resolve the behavioral algorithms and kinematics that determined the outcome of these interactions. In this context, the hydrodynamics of intermediate Reynolds numbers largely determines the range of flow stimuli and the limits to locomotor performance at dictate prey survival. These principles have the potential to apply to a broad diversity of fishes and other aquatic animals. ONR: N00014-15-1-2249.

  3. Myocardial Polyploidization Creates a Barrier to Heart Regeneration in Zebrafish.

    Science.gov (United States)

    González-Rosa, Juan Manuel; Sharpe, Michka; Field, Dorothy; Soonpaa, Mark H; Field, Loren J; Burns, Caroline E; Burns, C Geoffrey

    2018-02-26

    Correlative evidence suggests that polyploidization of heart muscle, which occurs naturally in post-natal mammals, creates a barrier to heart regeneration. Here, we move beyond a correlation by demonstrating that experimental polyploidization of zebrafish cardiomyocytes is sufficient to suppress their proliferative potential during regeneration. Initially, we determined that zebrafish myocardium becomes susceptible to polyploidization upon transient cytokinesis inhibition mediated by dominant-negative Ect2. Using a transgenic strategy, we generated adult animals containing mosaic hearts composed of differentially labeled diploid and polyploid-enriched cardiomyocyte populations. Diploid cardiomyocytes outcompeted their polyploid neighbors in producing regenerated heart muscle. Moreover, hearts composed of equivalent proportions of diploid and polyploid cardiomyocytes failed to regenerate altogether, demonstrating that a critical percentage of diploid cardiomyocytes is required to achieve heart regeneration. Our data identify cardiomyocyte polyploidization as a barrier to heart regeneration and suggest that mobilizing rare diploid cardiomyocytes in the human heart will improve its regenerative capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Caspase-mediated apoptosis induction in zebrafish cerebellar Purkinje neurons.

    Science.gov (United States)

    Weber, Thomas; Namikawa, Kazuhiko; Winter, Barbara; Müller-Brown, Karina; Kühn, Ralf; Wurst, Wolfgang; Köster, Reinhard W

    2016-11-15

    The zebrafish is a well-established model organism in which to study in vivo mechanisms of cell communication, differentiation and function. Existing cell ablation methods are either invasive or they rely on the cellular expression of prokaryotic enzymes and the use of antibiotic drugs as cell death-inducing compounds. We have recently established a novel inducible genetic cell ablation system based on tamoxifen-inducible Caspase 8 activity, thereby exploiting mechanisms of cell death intrinsic to most cell types. Here, we prove its suitability in vivo by monitoring the ablation of cerebellar Purkinje cells (PCs) in transgenic zebrafish that co-express the inducible caspase and a fluorescent reporter. Incubation of larvae in tamoxifen for 8 h activated endogenous Caspase 3 and cell death, whereas incubation for 16 h led to the near-complete loss of PCs by apoptosis. We observed synchronous cell death autonomous to the PC population and phagocytosing microglia in the cerebellum, reminiscent of developmental apoptosis in the forebrain. Thus, induction of apoptosis through targeted activation of caspase by tamoxifen (ATTAC TM ) further expands the repertoire of genetic tools for conditional interrogation of cellular functions. © 2016. Published by The Company of Biologists Ltd.

  5. LSD1 is Required for Hair Cell Regeneration in Zebrafish.

    Science.gov (United States)

    He, Yingzi; Tang, Dongmei; Cai, Chengfu; Chai, Renjie; Li, Huawei

    2016-05-01

    Lysine-specific demethylase 1 (LSD1/KDM1A) plays an important role in complex cellular processes such as differentiation, proliferation, apoptosis, and cell cycle progression. It has recently been demonstrated that during development, downregulation of LSD1 inhibits cell proliferation, modulates the expression of cell cycle regulators, and reduces hair cell formation in the zebrafish lateral line, which suggests that LSD1-mediated epigenetic regulation plays a key role in the development of hair cells. However, the role of LSD1 in hair cell regeneration after hair cell loss remains poorly understood. Here, we demonstrate the effect of LSD1 on hair cell regeneration following neomycin-induced hair cell loss. We show that the LSD1 inhibitor trans-2-phenylcyclopropylamine (2-PCPA) significantly decreases the regeneration of hair cells in zebrafish after neomycin damage. In addition, immunofluorescent staining demonstrates that 2-PCPA administration suppresses supporting cell proliferation and alters cell cycle progression. Finally, in situ hybridization shows that 2-PCPA significantly downregulates the expression of genes related to Wnt/β-catenin and Fgf activation. Altogether, our data suggest that downregulation of LSD1 significantly decreases hair cell regeneration after neomycin-induced hair cell loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus, LSD1 plays a critical role in hair cell regeneration and might represent a novel biomarker and potential therapeutic approach for the treatment of hearing loss.

  6. Short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish (Danio rerio).

    Science.gov (United States)

    Cao, Fangjie; Wu, Peizhuo; Huang, Lan; Li, Hui; Qian, Le; Pang, Sen; Qiu, Lihong

    2018-05-01

    Previous study indicated that azoxystrobin had high acute toxicity to zebrafish, and larval zebrafish were more sensitive to azoxystrobin than adult zebrafish. The objective of the present study was to investigate short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish. After zebrafish embryos and adults were exposed to 0.01, 0.05 and 0.20 mg/L azoxystrobin (equal to 25, 124 and 496 nM azoxystrobin, respectively) for 8 days, the lethal effect, physiological responses, liver histology, mitochondrial ultrastructure, and expression alteration of genes related to mitochondrial respiration, oxidative stress, cell apoptosis and innate immune response were determined. The results showed that there was no significant effect on larval and adult zebrafish after exposure to 0.01 mg/L azoxystrobin. However, increased ROS, MDA concentration and il1b in larval zebrafish, as well as increased il1b, il8 and cxcl-c1c in adult zebrafish were induced after exposure to 0.05 mg/L azoxystrobin. Reduced mitochondrial complex III activity and ATP concentration, increased SOD activity, ROS and MDA concentration, decreased cytb, as well as increased sod1, sod2, cat, il1b, il8 and cxcl-c1c were observed both in larval and adult zebrafish after exposure to 0.20 mg/L azoxystrobin; meanwhile, increased p53, bax, apaf1 and casp9, alteration of liver histology and mitochondrial ultrastructure in larval zebrafish, and alteration of mitochondrial ultrastructure in adult zebrafish were also induced. The results demonstrated that azoxytrobin induced short-term developmental effects on larval zebrafish and adult zebrafish, including mitochondrial dysfunction, oxidative stress, cell apoptosis and innate immune response. Statistical analysis indicated that azoxystrobin induced more negative effects on larval zebrafish, which might be the reason for the differences of developmental toxicity between larval and adult zebrafish caused by

  7. Expanded progenitor populations, vitreo-retinal abnormalities, and Müller glial reactivity in the zebrafish leprechaun/patched2 retina

    Directory of Open Access Journals (Sweden)

    Bibliowicz Jonathan

    2009-10-01

    Full Text Available Abstract Background The roles of the Hedgehog (Hh pathway in controlling vertebrate retinal development have been studied extensively; however, species- and context-dependent findings have provided differing conclusions. Hh signaling has been shown to control both population size and cell cycle kinetics of proliferating retinal progenitors, and to modulate differentiation within the retina by regulating the timing of cell cycle exit. While cell cycle exit has in turn been shown to control cell fate decisions within the retina, a direct role for the Hh pathway in retinal cell fate decisions has yet to be established in vivo. Results To gain further insight into Hh pathway function in the retina, we have analyzed retinal development in leprechaun/patched2 mutant zebrafish. While lep/ptc2 mutants possessed more cells in their retinas, all cell types, except for Müller glia, were present at identical ratios as those observed in wild-type siblings. lep/ptc2 mutants possessed a localized upregulation of GFAP, a marker for 'reactive' glia, as well as morphological abnormalities at the vitreo-retinal interface, where Müller glial endfeet terminate. In addition, analysis of the over-proliferation phenotype at the ciliary marginal zone (CMZ revealed that the number of proliferating progenitors, but not the rate of proliferation, was increased in lep/ptc2 mutants. Conclusion Our results indicate that Patched2-dependent Hh signaling does not likely play an integral role in neuronal cell fate decisions in the zebrafish retina. ptc2 deficiency in zebrafish results in defects at the vitreo-retinal interface and Müller glial reactivity. These phenotypes are similar to the ocular abnormalities observed in human patients suffering from Basal Cell Naevus Syndrome (BCNS, a disorder that has been linked to mutations in the human PTCH gene (the orthologue of the zebrafish ptc2, and point to the utility of the lep/ptc2 mutant line as a model for the study of BCNS

  8. Biotransformation in the zebrafish embryo -temporal gene transcription changes of cytochrome P450 enzymes and internal exposure dynamics of the AhR binding xenobiotic benz[a]anthracene.

    Science.gov (United States)

    Kühnert, Agnes; Vogs, Carolina; Seiwert, Bettina; Aulhorn, Silke; Altenburger, Rolf; Hollert, Henner; Küster, Eberhard; Busch, Wibke

    2017-11-01

    Not much is known about the biotransformation capability of zebrafish (Danio rerio) embryos. For understanding possible toxicity differences to adult fish, it might be crucial to understand the biotransformation of chemicals in zebrafish embryos i.e. as part of toxicokinetics. The biotransformation capabilities were analysed for two different stages of zebrafish embryos in conjunction with the internal concentrations of a xenobiotic. Zebrafish embryos of the late cleavage/early blastula period (2-26 hpf) and the early pharyngula period (26-50 hpf) were exposed for 24 h to the AhR binding compound benz[a]anthracene (BaA). Time dependent changes in cyp transcription (cyp1a, cyp1b1, cyp1c1 and cyp1c2) as well as concentration & time-dependent courses of BaA in the fish embryo and the exposure medium were analysed. Additionally, the CYP mediated formation of biotransformation products was investigated. We found correlations between transcriptional responses and the internal concentration for both exposure types. These correlations were depending on the start of the exposure i.e. the age of the exposed embryo. While no significant induction of the examined gene transcripts was observed in the first 12 h of exposure beginning in the blastula period a correlation was apparent when exposure started later i.e. in the pharyngula period. A significant induction of cyp1a was detected already after 1.5 h of BaA exposure. Gene transcripts for cyp1b1, cyp1c1 and cyp1c2 showed expressions distinctly different from cyp1a and were, in general, less inducible by BaA in both exposure windows. The toxicokinetic analysis showed that the biotransformation capability was fivefold higher in the older fish embryos. Biotransformation products of phase I reactions were found between 32 hpf and 50 hpf and were tentatively identified as benz[a]anthracene-phenol and benz[a]anthracene-dihydrodiol-epoxide. In conclusion, not only duration but also onset of exposure in relation to the

  9. The French press: a repeatable and high-throughput approach to exercising zebrafish (Danio rerio).

    Science.gov (United States)

    Usui, Takuji; Noble, Daniel W A; O'Dea, Rose E; Fangmeier, Melissa L; Lagisz, Malgorzata; Hesselson, Daniel; Nakagawa, Shinichi

    2018-01-01

    Zebrafish are increasingly used as a vertebrate model organism for various traits including swimming performance, obesity and metabolism, necessitating high-throughput protocols to generate standardized phenotypic information. Here, we propose a novel and cost-effective method for exercising zebrafish, using a coffee plunger and magnetic stirrer. To demonstrate the use of this method, we conducted a pilot experiment to show that this simple system provides repeatable estimates of maximal swim performance (intra-class correlation [ICC] = 0.34-0.41) and observe that exercise training of zebrafish on this system significantly increases their maximum swimming speed. We propose this high-throughput and reproducible system as an alternative to traditional linear chamber systems for exercising zebrafish and similarly sized fishes.

  10. Relationships among msx gene structure and function in zebrafish and other vertebrates.

    Science.gov (United States)

    Ekker, M; Akimenko, M A; Allende, M L; Smith, R; Drouin, G; Langille, R M; Weinberg, E S; Westerfield, M

    1997-10-01

    The zebrafish genome contains at least five msx homeobox genes, msxA, msxB, msxC, msxD, and the newly isolated msxE. Although these genes share structural features common to all Msx genes, phylogenetic analyses of protein sequences indicate that the msx genes from zebrafish are not orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians. The zebrafish msxB and msxC are more closely related to each other and to the mouse Msx3. Similarly, although the combinatorial expression of the zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches, fins, and sensory organs suggests functional similarities with the Msx genes of other vertebrates, differences in the expression patterns preclude precise assignment of orthological relationships. Distinct duplication events may have given rise to the msx genes of modern fish and other vertebrate lineages whereas many aspects of msx gene functions during embryonic development have been preserved.

  11. Zebrafish as a Model for the Study of Human Myeloid Malignancies

    Directory of Open Access Journals (Sweden)

    Jeng-Wei Lu

    2015-01-01

    Full Text Available Myeloid malignancies are heterogeneous disorders characterized by uncontrolled proliferation or/and blockage of differentiation of myeloid progenitor cells. Although a substantial number of gene alterations have been identified, the mechanism by which these abnormalities interact has yet to be elucidated. Over the past decades, zebrafish have become an important model organism, especially in biomedical research. Several zebrafish models have been developed to recapitulate the characteristics of specific myeloid malignancies that provide novel insight into the pathogenesis of these diseases and allow the evaluation of novel small molecule drugs. This report will focus on illustrative examples of applications of zebrafish models, including transgenesis, zebrafish xenograft models, and cell transplantation approaches, to the study of human myeloid malignancies.

  12. A Simple Setup to Perform 3D Locomotion Tracking in Zebrafish by Using a Single Camera

    Directory of Open Access Journals (Sweden)

    Gilbert Audira

    2018-02-01

    Full Text Available Generally, the measurement of three-dimensional (3D swimming behavior in zebrafish relies on commercial software or requires sophisticated scripts, and depends on more than two cameras to capture the video. Here, we establish a simple and economic apparatus to detect 3D locomotion in zebrafish, which involves a single camera capture system that records zebrafish movement in a specially designed water tank with a mirror tilted at 45 degrees. The recorded videos are analyzed using idTracker, while spatial positions are calibrated by ImageJ software and 3D trajectories are plotted by Origin 9.1 software. This easy setting allowed scientists to track 3D swimming behavior of multiple zebrafish with low cost and precise spatial position, showing great potential for fish behavioral research in the future.

  13. Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

    Science.gov (United States)

    Hong, Ni; Chen, Songlin; Ge, Ruowen; Song, Jianxing; Yi, Meisheng; Hong, Yunhan

    2012-08-10

    Chimera formation is a standard test for pluripotency of stem cells in vivo. Interspecific chimera formation between distantly related organisms offers also an attractive approach for propagating endangered species. Parameters influencing interspecies chimera formation have remained poorly elucidated. Here, we report interordinal chimera formation between medaka and zebrafish, which separated ∼320 million years ago and exhibit a more than 2-fold difference in developmental speed. We show that, on transplantation into zebrafish blastulae, both noncultivated blastomeres and long-term cultivated embryonic stem (ES) cells of medaka adopted the zebrafish developmental program and differentiated into physiologically functional cell types including pigment cells, blood cells, and cardiomyocytes. We also show that medaka ES cells express differentiation gene markers during chimeric embryogenesis. Therefore, the evolutionary distance and different embryogenesis speeds do not produce donor-host incompatibility to compromise chimera formation between medaka and zebrafish, and molecular markers are valuable for analyzing lineage commitment and cell differentiation in interspecific chimeric embryos.

  14. Endocrine disruption of courtship behaviour and reproduction in zebrafish (Danio rerio)

    DEFF Research Database (Denmark)

    Broch-Lips, Mia Gina Gruwier

    2011-01-01

    of the reversibility of hormonally induced shifts in sex ratio of zebrafish. In the first part of this study zebrafish were exposed to three different environmentally relevant concentrations of the synthetic oestrogen17α-ethinylestradiol (EE2) from egg stage to sexual maturity. Secondary sexual characteristics...... as fertilizing the spawned eggs. It was further demonstrated that the exposure to TB led to irreversible masculinisation of zebrafish which is in contrast with the partial reversibility of oestrogen induced sex change. During my investigations leading to this thesis it became apparent that sexual behaviour...... courtship behaviour have only been scarcely investigated. The aim of this project was to learn more about the effects of EDCS on the courtship behaviour and reproduction in zebrafish as well as investigating the reversibility of observed effects. I furthermore observed some interesting aspects...

  15. Zebrafish as a Model for the Study of Microvascular Complications of Diabetes and Their Mechanisms

    Directory of Open Access Journals (Sweden)

    Karl Heckler

    2017-09-01

    Full Text Available Diabetes mellitus (DM is a crucial metabolic disease that leads to severe disorders. These include macrovascular complications such as myocardial infarction, stroke, and peripheral artery disease and microvascular complications including diabetic nephropathy, neuropathy, and retinopathy. Diabetes mellitus, along with its associated organ pathologies, is one of the key problems in today’s medicine. Zebrafish is an upcoming disease model organism in diabetes research. Its glucose metabolism and the pathways of reactive metabolite formation are very similar to those of humans. Moreover, several physiological and pathophysiological pathways that also exist in humans and other mammals have been identified in this species or are currently under intense investigation. Zebrafish offer sophisticated imaging techniques and allow simple and fast genetic and pharmacological approaches with a high throughput. In this review, we highlight achievements and mechanisms concerning microvascular complications discovered in zebrafish, and we discuss the advantages and disadvantages of zebrafish as a model for studying diabetic complications.

  16. Zebrafish (Danio rerio) behavioural response to bioinspired robotic fish and mosquitofish (Gambusia affinis)

    International Nuclear Information System (INIS)

    Polverino, Giovanni; Porfiri, Maurizio

    2013-01-01

    The field of ethorobotics holds promise in aiding fundamental research in animal behaviour, whereby it affords fully controllable and easily reproducible experimental tools. Most of the current ethorobotics studies are focused on the behavioural response of a selected target species as it interacts with a biologically-inspired robot in controlled laboratory conditions. In this work, we first explore the interactions between two social fish species and a robotic fish, whose design is inspired by salient visual features of one of the species. Specifically, this study investigates the behavioural response of small shoals of zebrafish interacting with a zebrafish-inspired robotic fish and small shoals of mosquitofish in a basic ecological context. Our results demonstrate that the robotic fish differentially influences the behaviour of the two species by consistently attracting zebrafish, while repelling mosquitofish. This selective behavioural control is successful in spatially isolating the two species, which would otherwise exhibit prey–predator interactions, with mosquitofish attacking zebrafish. (communication)

  17. Microbiota colonization status influences developmental toxicity of bisphenol A in embryonic zebrafish

    Science.gov (United States)

    There is growing evidence that microbiota can modify the toxicokinetics and/or toxicodynamics of environmental chemicals. Commonly used mammalian systems have limited ability to link phenotypic effects in exposed animals to colonization status. Here, we used gnotobiotic zebrafish...

  18. Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance.

    Science.gov (United States)

    Ando, Kazunori; Shibata, Eri; Hans, Stefan; Brand, Michael; Kawakami, Atsushi

    2017-12-04

    Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Anastasia A. Batrakova

    2015-10-01

    This is the first study on the use of GMF for orientation in R. rutilus from a natural population. Our results confirm the presence of magnetosensitivity in roach. At the same time, the preferred direction in GMF matched the direction to the mouth of the channel where the fish were caught. It is possible that fish stressed by experimental manipulations have tried to “leave” the experimental arena in the usual direction of escape to the deep-water part of reservoir. Figure 1. Bimodal distribution of preferred directions in zebrafish by the reversal of vertical (a, horizontal (b, both vertical and horizontal (c components of GMF, and by the rotation of the horizontal component by 90 degrees clockwise (d. Distributions of preferred directions in control conditions (GMF for each experiment are given under corresponding diagrams (e, f, g, h. Figure 2. Distribution of preferred directions of roach in a GMF (a and the rotation of the horizontal component of the GMF by 90 degrees clockwise (b. Sample area with designation of the direction of the channel to the Rybinsk Reservoir (c. Asterisk shows the point of sampling.

  20. Evaluation of 5 Cleaning and Disinfection Methods for Nets Used to Collect Zebrafish (Danio rerio)

    OpenAIRE

    Collymore, Chereen; Porelli, Gina; Lieggi, Christine; Lipman, Neil S

    2014-01-01

    Few standardized methods of cleaning and disinfecting equipment in zebrafish facilities have been published, even though the effectiveness of these procedures is vital to preventing the transmission of pathogenic organisms. Four chemical disinfectants and rinsing with municipal tap water were evaluated for their ability to disinfect nets used to capture zebrafish. The disinfectants included benzalkonium chloride+methylene blue, sodium hypochlorite, chlorine dioxide, and potassium peroxymonosu...

  1. Large-scale assessment of the zebrafish embryo as a possible predictive model in toxicity testing.

    Directory of Open Access Journals (Sweden)

    Shaukat Ali

    Full Text Available BACKGROUND: In the drug discovery pipeline, safety pharmacology is a major issue. The zebrafish has been proposed as a model that can bridge the gap in this field between cell assays (which are cost-effective, but low in data content and rodent assays (which are high in data content, but less cost-efficient. However, zebrafish assays are only likely to be useful if they can be shown to have high predictive power. We examined this issue by assaying 60 water-soluble compounds representing a range of chemical classes and toxicological mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Over 20,000 wild-type zebrafish embryos (including controls were cultured individually in defined buffer in 96-well plates. Embryos were exposed for a 96 hour period starting at 24 hours post fertilization. A logarithmic concentration series was used for range-finding, followed by a narrower geometric series for LC(50 determination. Zebrafish embryo LC(50 (log mmol/L, and published data on rodent LD(50 (log mmol/kg, were found to be strongly correlated (using Kendall's rank correlation tau and Pearson's product-moment correlation. The slope of the regression line for the full set of compounds was 0.73403. However, we found that the slope was strongly influenced by compound class. Thus, while most compounds had a similar toxicity level in both species, some compounds were markedly more toxic in zebrafish than in rodents, or vice versa. CONCLUSIONS: For the substances examined here, in aggregate, the zebrafish embryo model has good predictivity for toxicity in rodents. However, the correlation between zebrafish and rodent toxicity varies considerably between individual compounds and compound class. We discuss the strengths and limitations of the zebrafish model in light of these findings.

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

    Science.gov (United States)

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

    2018-01-01

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

  3. Toxicity assessment of zebrafish following exposure to CdTe QDs

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei, E-mail: wzhang@ecust.edu.cn [State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237 (China); School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237 (China); Lin, Kuangfei, E-mail: kflin@ecust.edu.cn [State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237 (China); School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237 (China); Miao, Youna [State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237 (China); School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237 (China); Dong, Qiaoxiang; Huang, Changjiang; Wang, Huili [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Wenzhou Medical College, Wenzhou 325035 (China); Guo, Meijin [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Cui, Xinhong [Shanghai Institute of Landscape Gardening, Shanghai 200233 (China)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer The LC{sub 50} of TGA-CdTe for zebrafish at 120 hpf was 185.9 nM. Black-Right-Pointing-Pointer Zebrafish exposed to TGA-CdTe resulted in lower hatch rate and more malformation. Black-Right-Pointing-Pointer Body length and heart beat of zebrafish declined after exposure to TGA-CdTe. Black-Right-Pointing-Pointer Larvae exposure to TGA-CdTe elicited a higher basal swimming rate. Black-Right-Pointing-Pointer Abnormal vascular of FLI-1 transgenic zebrafish larvae exposed to TGA-CdTe occurred. - Abstract: CdTe quantum dots (QDs) are nanocrystals of unique composition and properties that have found many new commercial applications; therefore, their potential toxicity to aquatic organisms has become a hot research topic. The lab study was performed to determine the developmental and behavioral toxicities to zebrafish under continuous exposure to low concentrations of CdTe QDs (1-400 nM) coated with thioglycolic acid (TGA). The results show: (1) the 120 h LC{sub 50} of 185.9 nM, (2) the lower hatch rate and body length, more malformations, and less heart beat and swimming speed of the exposed zebrafish, (3) the brief burst and a higher basal swimming rate of the exposed zebrafish larvae during a rapid transition from light-to-dark, and (4) the vascular hyperplasia, vascular bifurcation, vascular crossing and turbulence of the exposed FLI-1 transgenic zebrafish larvae.

  4. Identification of estrogen target genes during zebrafish embryonic development through transcriptomic analysis.

    Directory of Open Access Journals (Sweden)

    Ruixin Hao

    Full Text Available Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 µM 17β-estradiol (E2 or vehicle from 3 hours to 4 days post fertilization (dpf, harvested at 1, 2, 3 and 4 dpf, and subjected to RNA extraction for transcriptome analysis using microarrays. Differentially expressed genes by E2-treatment were analyzed with hierarchical clustering followed by biological process and tissue enrichment analysis. Markedly distinct sets of genes were up and down-regulated by E2 at the four different time points. Among these genes, only the well-known estrogenic marker vtg1 was co-regulated at all time points. Despite this, the biological functional categories targeted by E2 were relatively similar throughout zebrafish development. According to knowledge-based tissue enrichment, estrogen responsive genes were clustered mainly in the liver, pancreas and brain. This was in line with the developmental dynamics of estrogen-target tissues that were visualized using transgenic zebrafish containing estrogen responsive elements driving the expression of GFP (Tg(5xERE:GFP. Finally, the identified embryonic estrogen-responsive genes were compared to already published estrogen-responsive genes identified in male adult zebrafish (Gene Expression Omnibus database. The expressions of a few genes were co-regulated by E2 in both embryonic and adult zebrafish. These could potentially be used as estrogenic biomarkers for exposure to estrogens or estrogenic endocrine disruptors in zebrafish. In conclusion, our data suggests that estrogen effects on early embryonic zebrafish development are stage- and tissue- specific.

  5. Generation of orientation tools for automated zebrafish screening assays using desktop 3D printing

    OpenAIRE

    Wittbrodt, Jonas N.; Liebel, Urban; Gehrig, Jochen

    2014-01-01

    Background The zebrafish has been established as the main vertebrate model system for whole organism screening applications. However, the lack of consistent positioning of zebrafish embryos within wells of microtiter plates remains an obstacle for the comparative analysis of images acquired in automated screening assays. While technical solutions to the orientation problem exist, dissemination is often hindered by the lack of simple and inexpensive ways of distributing and duplicating tools. ...

  6. Characterization of brn1.2 and corticotropin-releasing hormone genes in zebrafish

    OpenAIRE

    Chandrasekar, Gayathri

    2007-01-01

    The zebrafish (Danio rerio), a tropical fresh water fish originally found in the rivers of India and Bangladesh has become a popular vertebrate model system over the last decade. The rapid sequencing of the zebrafish genome together with the latest advances in forward and reverse genetics has made this model organism more fascinating as it can be used to decipher the genetic mechanisms involved in the vertebrate development. Corticotropin-releasing hormone (CRH) regulates t...

  7. Gross and Fine Dissection of Inner Ear Sensory Epithelia in Adult Zebrafish (Danio rerio)

    OpenAIRE

    Liang, Jin; Burgess, Shawn M.

    2009-01-01

    Neurosensory epithelia in the inner ear are the crucial structures for hearing and balance functions. Therefore, it is important to understand the cellular and molecular features of the epithelia, which are mainly composed of two types of cells: hair cells (HCs) and supporting cells (SCs). Here we choose to study the inner ear sensory epithelia in adult zebrafish not only because the epithelial structures are highly conserved in all vertebrates studied, but also because the adult zebrafish is...

  8. Yoshiki Hotta and the dawn of zebrafish molecular neurogenetics in Japan.

    Science.gov (United States)

    Higashijima, Shin-Ichi; Okamoto, Hitoshi

    2012-03-01

    Abstract: After coming back to Japan to work in the Department of Physics at the University of Tokyo, Yoshiki Hotta spent a year or so on searching for behavioral mutants of goldfish. Although this endeavor did not succeed, he remained an adamant supporter of the development of zebrafish research in Japan. Here we review how his support helped zebrafish neurogenetics in Japan gain a unique position in the world research community.

  9. Reprimo tissue-specific expression pattern is conserved between zebrafish and human.

    Directory of Open Access Journals (Sweden)

    Ricardo J Figueroa

    Full Text Available Reprimo (RPRM, a member of the RPRM gene family, is a tumor-suppressor gene involved in the regulation of the p53-mediated cell cycle arrest at G2/M. RPRM has been associated with malignant tumor progression and proposed as a potential biomarker for early cancer detection. However, the expression and role of RPRM, as well as its family, are poorly understood and their physiology is as yet unstudied. In this scenario, a model system like the zebrafish could serve to dissect the role of the RPRM family members in vivo. Phylogenetic analysis reveals that RPRM and RPRML have been differentially retained by most species throughout vertebrate evolution, yet RPRM3 has been retained only in a small group of distantly related species, including zebrafish. Herein, we characterized the spatiotemporal expression of RPRM (present in zebrafish as an infraclass duplication rprma/rprmb, RPRML and RPRM3 in the zebrafish. By whole-mount in situ hybridization (WISH and fluorescent in situ hybridization (FISH, we demonstrate that rprm (rprma/rprmb and rprml show a similar spatiotemporal expression profile during zebrafish development. At early developmental stages rprmb is expressed in somites. After one day post-fertilization, rprm (rprma/rprmb and rprml are expressed in the notochord, brain, blood vessels and digestive tube. On the other hand, rprm3 shows the most unique expression profile, being expressed only in the central nervous system (CNS. We assessed the expression patterns of RPRM gene transcripts in adult zebrafish and human RPRM protein product in tissue samples by RT-qPCR and immunohistochemistry (IHC staining, respectively. Strikingly, tissue-specific expression patterns of the RPRM transcripts and protein are conserved between zebrafish and humans. We propose the zebrafish as a powerful tool to elucidate the both physiological and pathological roles of the RPRM gene family.

  10. Zebrafish as a model to study the neuroendocrine system and toxicity of endocrine disruptors

    OpenAIRE

    Chandrasekar, Gayathri

    2011-01-01

    Zebrafish is a popular vertebrate model system to study development and perform genetic analysis. It offers numerous advantages such as small size, short generation time, high fecundity, rapid and ex utero development of embryos and optically transparent embryos. Zebrafish is genetically closely related to humans and share high similarity in developmental processes, physiology and behavior. In addition, recent advances in forward and reverse genetics coupled with the availabili...

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

    OpenAIRE

    Garcia, Rachel L; Sanders, George E

    2011-01-01

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

  12. Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage

    OpenAIRE

    Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

    2014-01-01

    In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and ...

  13. Antigen Uptake during Different Life Stages of Zebrafish (Danio rerio) Using a GFP-Tagged Yersinia ruckeri

    DEFF Research Database (Denmark)

    Korbut, Rozalia; Mehrdana, Foojan; Kania, Per Walter

    2016-01-01

    Immersion-vaccines (bacterins) are routinely used for aquacultured rainbow trout to protect against Yersinia ruckeri (Yr). During immersion vaccination, rainbow trout take up and process the antigens, which induce protection. The zebrafish was used as a model organism to study uptake mechanisms...... the gut was consistently a major uptake site. Zebrafish and rainbow trout tend to have similar uptake mechanisms following immersion or bath vaccination, which points towards zebrafish as a suitable model organism for this aquacultured species....

  14. Comprehensive analysis of coding-lncRNA gene co-expression network uncovers conserved functional lncRNAs in zebrafish.

    Science.gov (United States)

    Chen, Wen; Zhang, Xuan; Li, Jing; Huang, Shulan; Xiang, Shuanglin; Hu, Xiang; Liu, Changning

    2018-05-09

    Zebrafish is a full-developed model system for studying development processes and human disease. Recent studies of deep sequencing had discovered a large number of long non-coding RNAs (lncRNAs) in zebrafish. However, only few of them had been functionally characterized. Therefore, how to take advantage of the mature zebrafish system to deeply investigate the lncRNAs' function and conservation is really intriguing. We systematically collected and analyzed a series of zebrafish RNA-seq data, then combined them with resources from known database and literatures. As a result, we obtained by far the most complete dataset of zebrafish lncRNAs, containing 13,604 lncRNA genes (21,128 transcripts) in total. Based on that, a co-expression network upon zebrafish coding and lncRNA genes was constructed and analyzed, and used to predict the Gene Ontology (GO) and the KEGG annotation of lncRNA. Meanwhile, we made a conservation analysis on zebrafish lncRNA, identifying 1828 conserved zebrafish lncRNA genes (1890 transcripts) that have their putative mammalian orthologs. We also found that zebrafish lncRNAs play important roles in regulation of the development and function of nervous system; these conserved lncRNAs present a significant sequential and functional conservation, with their mammalian counterparts. By integrative data analysis and construction of coding-lncRNA gene co-expression network, we gained the most comprehensive dataset of zebrafish lncRNAs up to present, as well as their systematic annotations and comprehensive analyses on function and conservation. Our study provides a reliable zebrafish-based platform to deeply explore lncRNA function and mechanism, as well as the lncRNA commonality between zebrafish and human.

  15. Zebrafish as an In Vivo Model to Assess Epigenetic Effects of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Eva Yi Kong

    2016-12-01

    Full Text Available Exposure to ionizing radiations (IRs is ubiquitous in our environment and can be categorized into “targeted” effects and “non-targeted” effects. In addition to inducing deoxyribonucleic acid (DNA damage, IR exposure leads to epigenetic alterations that do not alter DNA sequence. Using an appropriate model to study the biological effects of radiation is crucial to better understand IR responses as well as to develop new strategies to alleviate exposure to IR. Zebrafish, Danio rerio, is a scientific model organism that has yielded scientific advances in several fields and recent studies show the usefulness of this vertebrate model in radiation biology. This review briefly describes both “targeted” and “non-targeted” effects, describes the findings in radiation biology using zebrafish as a model and highlights the potential of zebrafish to assess the epigenetic effects of IR, including DNA methylation, histone modifications and miRNA expression. Other in vivo models are included to compare observations made with zebrafish, or to illustrate the feasibility of in vivo models when the use of zebrafish was unavailable. Finally, tools to study epigenetic modifications in zebrafish, including changes in genome-wide DNA methylation, histone modifications and miRNA expression, are also described in this review.

  16. Spatial pattern of cell geometry and cell-division orientation in zebrafish lens epithelium

    Directory of Open Access Journals (Sweden)

    Toshiaki Mochizuki

    2014-09-01

    Full Text Available Cell proliferation is a key regulator of tissue morphogenesis. We examined cell proliferation and cell division in zebrafish lens epithelium by visualizing cell-cycle phases and nuclear positions, using fluorescent-labeled geminin and histone proteins. Proliferation was low in the anterior region of lens epithelium and higher in the marginal zone anterior to the equator, suggesting that the proliferation zone, called the germinative zone, is formed in zebrafish lens. Interestingly, cell-division orientation was biased longitudinally in the anterior region, shifted from longitudinal to circumferential along the anterior–posterior axis of lens sphere, and was biased circumferentially in the peripheral region. These data suggest that cell-division orientation is spatially regulated in zebrafish lens epithelium. The Hertwig rule indicates that cells tend to divide along their long axes. Orientation of long axes and cell division were biased similarly in zebrafish lens epithelium, suggesting that cell geometry correlates with cell-division orientation. A cell adhesion molecule, E-cadherin, is expressed in lens epithelium. In a zebrafish e-cadherin mutant, the long axes and cell-division orientation were shifted more longitudinally. These data suggest that E-cadherin is required for the spatial pattern of cell geometry and cell-division orientation in zebrafish lens epithelium.

  17. Zebrafish Models of Prader-Willi Syndrome: Fast Track to Pharmacotherapeutics

    Directory of Open Access Journals (Sweden)

    Emma D. Spikol

    2016-03-01

    Full Text Available Prader-Willi syndrome (PWS is a rare genetic neurodevelopmental disorder characterized by an insatiable appetite, leading to chronic overeating and obesity. Additional features include short stature, intellectual disability, behavioral problems and incomplete sexual development. Although significant progress has been made in understanding the genetic basis of PWS, the mechanisms underlying the pathogenesis of the disorder remain poorly understood. Treatment for PWS consists mainly of palliative therapies; curative therapies are sorely needed. Zebrafish, Danio rerio, represent a promising way forward for elucidating physiological problems such as obesity and identifying new pharmacotherapeutic options for PWS. Over the last decade, an increased appreciation for the highly conserved biology among vertebrates and the ability to perform high-throughput drug screening has seen an explosion in the use of zebrafish for disease modeling and drug discovery. Here, we review recent advances in developing zebrafish models of human disease. Aspects of zebrafish genetics and physiology that are relevant to PWS will be discussed, and the advantages and disadvantages of zebrafish models will be contrasted with current animal models for this syndrome. Finally, we will present a paradigm for drug screening in zebrafish that is potentially the fastest route for identifying and delivering curative pharmacotherapies to PWS patients.

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

    Science.gov (United States)

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

    2016-04-01

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

  19. Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish.

    Science.gov (United States)

    Lim, K-H; Chang, Y-C; Chiang, Y-H; Lin, H-C; Chang, C-Y; Lin, C-S; Huang, L; Wang, W-T; Gon-Shen Chen, C; Chou, W-C; Kuo, Y-Y

    2016-10-07

    CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.

  20. The zebrafish reference genome sequence and its relationship to the human genome

    Science.gov (United States)

    Howe, Kerstin; Clark, Matthew D.; Torroja, Carlos F.; Torrance, James; Berthelot, Camille; Muffato, Matthieu; Collins, John E.; Humphray, Sean; McLaren, Karen; Matthews, Lucy; McLaren, Stuart; Sealy, Ian; Caccamo, Mario; Churcher, Carol; Scott, Carol; Barrett, Jeffrey C.; Koch, Romke; Rauch, Gerd-Jörg; White, Simon; Chow, William; Kilian, Britt; Quintais, Leonor T.; Guerra-Assunção, José A.; Zhou, Yi; Gu, Yong; Yen, Jennifer; Vogel, Jan-Hinnerk; Eyre, Tina; Redmond, Seth; Banerjee, Ruby; Chi, Jianxiang; Fu, Beiyuan; Langley, Elizabeth; Maguire, Sean F.; Laird, Gavin K.; Lloyd, David; Kenyon, Emma; Donaldson, Sarah; Sehra, Harminder; Almeida-King, Jeff; Loveland, Jane; Trevanion, Stephen; Jones, Matt; Quail, Mike; Willey, Dave; Hunt, Adrienne; Burton, John; Sims, Sarah; McLay, Kirsten; Plumb, Bob; Davis, Joy; Clee, Chris; Oliver, Karen; Clark, Richard; Riddle, Clare; Eliott, David; Threadgold, Glen; Harden, Glenn; Ware, Darren; Mortimer, Beverly; Kerry, Giselle; Heath, Paul; Phillimore, Benjamin; Tracey, Alan; Corby, Nicole; Dunn, Matthew; Johnson, Christopher; Wood, Jonathan; Clark, Susan; Pelan, Sarah; Griffiths, Guy; Smith, Michelle; Glithero, Rebecca; Howden, Philip; Barker, Nicholas; Stevens, Christopher; Harley, Joanna; Holt, Karen; Panagiotidis, Georgios; Lovell, Jamieson; Beasley, Helen; Henderson, Carl; Gordon, Daria; Auger, Katherine; Wright, Deborah; Collins, Joanna; Raisen, Claire; Dyer, Lauren; Leung, Kenric; Robertson, Lauren; Ambridge, Kirsty; Leongamornlert, Daniel; McGuire, Sarah; Gilderthorp, Ruth; Griffiths, Coline; Manthravadi, Deepa; Nichol, Sarah; Barker, Gary; Whitehead, Siobhan; Kay, Michael; Brown, Jacqueline; Murnane, Clare; Gray, Emma; Humphries, Matthew; Sycamore, Neil; Barker, Darren; Saunders, David; Wallis, Justene; Babbage, Anne; Hammond, Sian; Mashreghi-Mohammadi, Maryam; Barr, Lucy; Martin, Sancha; Wray, Paul; Ellington, Andrew; Matthews, Nicholas; Ellwood, Matthew; Woodmansey, Rebecca; Clark, Graham; Cooper, James; Tromans, Anthony; Grafham, Darren; Skuce, Carl; Pandian, Richard; Andrews, Robert; Harrison, Elliot; Kimberley, Andrew; Garnett, Jane; Fosker, Nigel; Hall, Rebekah; Garner, Patrick; Kelly, Daniel; Bird, Christine; Palmer, Sophie; Gehring, Ines; Berger, Andrea; Dooley, Christopher M.; Ersan-Ürün, Zübeyde; Eser, Cigdem; Geiger, Horst; Geisler, Maria; Karotki, Lena; Kirn, Anette; Konantz, Judith; Konantz, Martina; Oberländer, Martina; Rudolph-Geiger, Silke; Teucke, Mathias; Osoegawa, Kazutoyo; Zhu, Baoli; Rapp, Amanda; Widaa, Sara; Langford, Cordelia; Yang, Fengtang; Carter, Nigel P.; Harrow, Jennifer; Ning, Zemin; Herrero, Javier; Searle, Steve M. J.; Enright, Anton; Geisler, Robert; Plasterk, Ronald H. A.; Lee, Charles; Westerfield, Monte; de Jong, Pieter J.; Zon, Leonard I.; Postlethwait, John H.; Nüsslein-Volhard, Christiane; Hubbard, Tim J. P.; Crollius, Hugues Roest; Rogers, Jane; Stemple, Derek L.

    2013-01-01

    Zebrafish have become a popular organism for the study of vertebrate gene function1,2. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease3–5. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes6, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination. PMID:23594743

  1. Metastatic behaviour of primary human tumours in a zebrafish xenotransplantation model

    International Nuclear Information System (INIS)

    Marques, Ines J; Bagowski, Christoph P; Weiss, Frank Ulrich; Vlecken, Danielle H; Nitsche, Claudia; Bakkers, Jeroen; Lagendijk, Anne K; Partecke, Lars Ivo; Heidecke, Claus-Dieter; Lerch, Markus M

    2009-01-01

    Aberrant regulation of cell migration drives progression of many diseases, including cancer cell invasion and metastasis formation. Analysis of tumour invasion and metastasis in living organisms to date is cumbersome and involves difficult and time consuming investigative techniques. For primary human tumours we establish here a simple, fast, sensitive and cost-effective in vivo model to analyse tumour invasion and metastatic behaviour. We fluorescently labelled small explants from gastrointestinal human tumours and investigated their metastatic behaviour after transplantation into zebrafish embryos and larvae. The transparency of the zebrafish embryos allows to follow invasion, migration and micrometastasis formation in real-time. High resolution imaging was achieved through laser scanning confocal microscopy of live zebrafish. In the transparent zebrafish embryos invasion, circulation of tumour cells in blood vessels, migration and micrometastasis formation can be followed in real-time. Xenografts of primary human tumours showed invasiveness and micrometastasis formation within 24 hours after transplantation, which was absent when non-tumour tissue was implanted. Furthermore, primary human tumour cells, when organotopically implanted in the zebrafish liver, demonstrated invasiveness and metastatic behaviour, whereas primary control cells remained in the liver. Pancreatic tumour cells showed no metastatic behaviour when injected into cloche mutant embryos, which lack a functional vasculature. Our results show that the zebrafish is a useful in vivo animal model for rapid analysis of invasion and metastatic behaviour of primary human tumour specimen

  2. Zebrafish as a potential model organism for drug test against hepatitis C virus.

    Directory of Open Access Journals (Sweden)

    Cun-Bao Ding

    Full Text Available Screening and evaluating anti- hepatitis C virus (HCV drugs in vivo is difficult worldwide, mainly because of the lack of suitable small animal models. We investigate whether zebrafish could be a model organism for HCV replication. To achieve NS5B-dependent replication an HCV sub-replicon was designed and created with two vectors, one with HCV ns5b and fluorescent rfp genes, and the other containing HCV's 5'UTR, core, 3'UTR and fluorescent gfp genes. The vectors containing sub-replicons were co-injected into zebrafish zygotes. The sub-replicon amplified in liver showing a significant expression of HCV core RNA and protein. The sub-replicon amplification caused no abnormality in development and growth of zebrafish larvae, but induced gene expression change similar to that in human hepatocytes. As the amplified core fluorescence in live zebrafish was detectable microscopically, it rendered us an advantage to select those with replicating sub-replicon for drug experiments. Ribavirin and oxymatrine, two known anti-HCV drugs, inhibited sub-replicon amplification in this model showing reduced levels of HCV core RNA and protein. Technically, this method had a good reproducibility and is easy to operate. Thus, zebrafish might be a model organism to host HCV, and this zebrafish/HCV (sub-replicon system could be an animal model for anti-HCV drug screening and evaluation.

  3. Toxicity of multi-walled carbon nanotubes, graphene oxide, and reduced graphene oxide to zebrafish embryos.

    Science.gov (United States)

    Liu, Xiao Tong; Mu, Xi Yan; Wu, Xiao Li; Meng, Li Xuan; Guan, Wen Bi; Ma, Yong Qiang; Sun, Hua; Wang, Cheng Ju; Li, Xue Feng

    2014-09-01

    This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), and reduced graphene oxide (RGO), on zebrafish embryos. The 2-h post-fertilization (hpf) zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations (1, 5, 10, 50, 100 mg/L) for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations ls were evaluated. Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials. MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  4. Fishing for Nature's Hits: Establishment of the Zebrafish as a Model for Screening Antidiabetic Natural Products.

    Science.gov (United States)

    Tabassum, Nadia; Tai, Hongmei; Jung, Da-Woon; Williams, Darren R

    2015-01-01

    Diabetes mellitus affects millions of people worldwide and significantly impacts their quality of life. Moreover, life threatening diseases, such as myocardial infarction, blindness, and renal disorders, increase the morbidity rate associated with diabetes. Various natural products from medicinal plants have shown potential as antidiabetes agents in cell-based screening systems. However, many of these potential "hits" fail in mammalian tests, due to issues such as poor pharmacokinetics and/or toxic side effects. To address this problem, the zebrafish (Danio rerio) model has been developed as a "bridge" to provide an experimentally convenient animal-based screening system to identify drug candidates that are active in vivo. In this review, we discuss the application of zebrafish to drug screening technologies for diabetes research. Specifically, the discovery of natural product-based antidiabetes compounds using zebrafish will be described. For example, it has recently been demonstrated that antidiabetic natural compounds can be identified in zebrafish using activity guided fractionation of crude plant extracts. Moreover, the development of fluorescent-tagged glucose bioprobes has allowed the screening of natural product-based modulators of glucose homeostasis in zebrafish. We hope that the discussion of these advances will illustrate the value and simplicity of establishing zebrafish-based assays for antidiabetic compounds in natural products-based laboratories.

  5. Cerebroventricular Microinjection (CVMI) into Adult Zebrafish Brain Is an Efficient Misexpression Method for Forebrain Ventricular Cells

    Science.gov (United States)

    Kizil, Caghan; Brand, Michael

    2011-01-01

    The teleost fish Danio rerio (zebrafish) has a remarkable ability to generate newborn neurons in its brain at adult stages of its lifespan-a process called adult neurogenesis. This ability relies on proliferating ventricular progenitors and is in striking contrast to mammalian brains that have rather restricted capacity for adult neurogenesis. Therefore, investigating the zebrafish brain can help not only to elucidate the molecular mechanisms of widespread adult neurogenesis in a vertebrate species, but also to design therapies in humans with what we learn from this teleost. Yet, understanding the cellular behavior and molecular programs underlying different biological processes in the adult zebrafish brain requires techniques that allow manipulation of gene function. As a complementary method to the currently used misexpression techniques in zebrafish, such as transgenic approaches or electroporation-based delivery of DNA, we devised a cerebroventricular microinjection (CVMI)-assisted knockdown protocol that relies on vivo morpholino oligonucleotides, which do not require electroporation for cellular uptake. This rapid method allows uniform and efficient knockdown of genes in the ventricular cells of the zebrafish brain, which contain the neurogenic progenitors. We also provide data on the use of CVMI for growth factor administration to the brain – in our case FGF8, which modulates the proliferation rate of the ventricular cells. In this paper, we describe the CVMI method and discuss its potential uses in zebrafish. PMID:22076157

  6. The zebrafish reference genome sequence and its relationship to the human genome.

    Science.gov (United States)

    Howe, Kerstin; Clark, Matthew D; Torroja, Carlos F; Torrance, James; Berthelot, Camille; Muffato, Matthieu; Collins, John E; Humphray, Sean; McLaren, Karen; Matthews, Lucy; McLaren, Stuart; Sealy, Ian; Caccamo, Mario; Churcher, Carol; Scott, Carol; Barrett, Jeffrey C; Koch, Romke; Rauch, Gerd-Jörg; White, Simon; Chow, William; Kilian, Britt; Quintais, Leonor T; Guerra-Assunção, José A; Zhou, Yi; Gu, Yong; Yen, Jennifer; Vogel, Jan-Hinnerk; Eyre, Tina; Redmond, Seth; Banerjee, Ruby; Chi, Jianxiang; Fu, Beiyuan; Langley, Elizabeth; Maguire, Sean F; Laird, Gavin K; Lloyd, David; Kenyon, Emma; Donaldson, Sarah; Sehra, Harminder; Almeida-King, Jeff; Loveland, Jane; Trevanion, Stephen; Jones, Matt; Quail, Mike; Willey, Dave; Hunt, Adrienne; Burton, John; Sims, Sarah; McLay, Kirsten; Plumb, Bob; Davis, Joy; Clee, Chris; Oliver, Karen; Clark, Richard; Riddle, Clare; Elliot, David; Eliott, David; Threadgold, Glen; Harden, Glenn; Ware, Darren; Begum, Sharmin; Mortimore, Beverley; Mortimer, Beverly; Kerry, Giselle; Heath, Paul; Phillimore, Benjamin; Tracey, Alan; Corby, Nicole; Dunn, Matthew; Johnson, Christopher; Wood, Jonathan; Clark, Susan; Pelan, Sarah; Griffiths, Guy; Smith, Michelle; Glithero, Rebecca; Howden, Philip; Barker, Nicholas; Lloyd, Christine; Stevens, Christopher; Harley, Joanna; Holt, Karen; Panagiotidis, Georgios; Lovell, Jamieson; Beasley, Helen; Henderson, Carl; Gordon, Daria; Auger, Katherine; Wright, Deborah; Collins, Joanna; Raisen, Claire; Dyer, Lauren; Leung, Kenric; Robertson, Lauren; Ambridge, Kirsty; Leongamornlert, Daniel; McGuire, Sarah; Gilderthorp, Ruth; Griffiths, Coline; Manthravadi, Deepa; Nichol, Sarah; Barker, Gary; Whitehead, Siobhan; Kay, Michael; Brown, Jacqueline; Murnane, Clare; Gray, Emma; Humphries, Matthew; Sycamore, Neil; Barker, Darren; Saunders, David; Wallis, Justene; Babbage, Anne; Hammond, Sian; Mashreghi-Mohammadi, Maryam; Barr, Lucy; Martin, Sancha; Wray, Paul; Ellington, Andrew; Matthews, Nicholas; Ellwood, Matthew; Woodmansey, Rebecca; Clark, Graham; Cooper, James D; Cooper, James; Tromans, Anthony; Grafham, Darren; Skuce, Carl; Pandian, Richard; Andrews, Robert; Harrison, Elliot; Kimberley, Andrew; Garnett, Jane; Fosker, Nigel; Hall, Rebekah; Garner, Patrick; Kelly, Daniel; Bird, Christine; Palmer, Sophie; Gehring, Ines; Berger, Andrea; Dooley, Christopher M; Ersan-Ürün, Zübeyde; Eser, Cigdem; Geiger, Horst; Geisler, Maria; Karotki, Lena; Kirn, Anette; Konantz, Judith; Konantz, Martina; Oberländer, Martina; Rudolph-Geiger, Silke; Teucke, Mathias; Lanz, Christa; Raddatz, Günter; Osoegawa, Kazutoyo; Zhu, Baoli; Rapp, Amanda; Widaa, Sara; Langford, Cordelia; Yang, Fengtang; Schuster, Stephan C; Carter, Nigel P; Harrow, Jennifer; Ning, Zemin; Herrero, Javier; Searle, Steve M J; Enright, Anton; Geisler, Robert; Plasterk, Ronald H A; Lee, Charles; Westerfield, Monte; de Jong, Pieter J; Zon, Leonard I; Postlethwait, John H; Nüsslein-Volhard, Christiane; Hubbard, Tim J P; Roest Crollius, Hugues; Rogers, Jane; Stemple, Derek L

    2013-04-25

    Zebrafish have become a popular organism for the study of vertebrate gene function. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination.

  7. Comparison of the Exomes of Common Carp (Cyprinus carpio) and Zebrafish (Danio rerio)

    Science.gov (United States)

    Henkel, Christiaan V.; Dirks, Ron P.; Jansen, Hans J.; Forlenza, Maria; Wiegertjes, Geert F.; Howe, Kerstin; van den Thillart, Guido E.E.J.M.

    2012-01-01

    Abstract Research on common carp, Cyprinus carpio, is beneficial for zebrafish research because of resources available owing to its large body size, such as the availability of sufficient organ material for transcriptomics, proteomics, and metabolomics. Here we describe the shot gun sequencing of a clonal double-haploid common carp line. The assembly consists of 511891 scaffolds with an N50 of 17 kb, predicting a total genome size of 1.4–1.5 Gb. A detailed analysis of the ten largest scaffolds indicates that the carp genome has a considerably lower repeat coverage than zebrafish, whilst the average intron size is significantly smaller, making it comparable to the fugu genome. The quality of the scaffolding was confirmed by comparisons with RNA deep sequencing data sets and a manual analysis for synteny with the zebrafish, especially the Hox gene clusters. In the ten largest scaffolds analyzed, the synteny of genes is almost complete. Comparisons of predicted exons of common carp with those of the zebrafish revealed only few genes specific for either zebrafish or carp, most of these being of unknown function. This supports the hypothesis of an additional genome duplication event in the carp evolutionary history, which—due to a higher degree of compactness—did not result in a genome larger than that of zebrafish. PMID:22715948

  8. LITTLE FISH, BIG DATA: ZEBRAFISH AS A MODEL FOR CARDIOVASCULAR AND METABOLIC DISEASE.

    Science.gov (United States)

    Gut, Philipp; Reischauer, Sven; Stainier, Didier Y R; Arnaout, Rima

    2017-07-01

    The burden of cardiovascular and metabolic diseases worldwide is staggering. The emergence of systems approaches in biology promises new therapies, faster and cheaper diagnostics, and personalized medicine. However, a profound understanding of pathogenic mechanisms at the cellular and molecular levels remains a fundamental requirement for discovery and therapeutics. Animal models of human disease are cornerstones of drug discovery as they allow identification of novel pharmacological targets by linking gene function with pathogenesis. The zebrafish model has been used for decades to study development and pathophysiology. More than ever, the specific strengths of the zebrafish model make it a prime partner in an age of discovery transformed by big-data approaches to genomics and disease. Zebrafish share a largely conserved physiology and anatomy with mammals. They allow a wide range of genetic manipulations, including the latest genome engineering approaches. They can be bred and studied with remarkable speed, enabling a range of large-scale phenotypic screens. Finally, zebrafish demonstrate an impressive regenerative capacity scientists hope to unlock in humans. Here, we provide a comprehensive guide on applications of zebrafish to investigate cardiovascular and metabolic diseases. We delineate advantages and limitations of zebrafish models of human disease and summarize their most significant contributions to understanding disease progression to date. Copyright © 2017 the American Physiological Society.

  9. The Zebrafish Anillin-eGFP Reporter Marks Late Dividing Retinal Precursors and Stem Cells Entering Neuronal Lineages.

    Directory of Open Access Journals (Sweden)

    Meret Cepero Malo

    Full Text Available Monitoring cycling behaviours of stem and somatic cells in the living animal is a powerful tool to better understand tissue development and homeostasis. The tg(anillin:anillin-eGFP transgenic line carries the full-length zebrafish F-actin binding protein Anillin fused to eGFP from a bacterial artificial chromosome (BAC containing Anillin cis-regulatory sequences. Here we report the suitability of the Anillin-eGFP reporter as a direct indicator of cycling cells in the late embryonic and post-embryonic retina. We show that combining the anillin:anillin-eGFP with other transgenes such as ptf1a:dsRed and atoh7:gap-RFP allows obtaining spatial and temporal resolution of the mitotic potentials of specific retinal cell populations. This is exemplified by the analysis of the origin of the previously reported apically and non-apically dividing late committed precursors of the photoreceptor and horizontal cell layers.

  10. Short- and long-term effects of nicotine and the histone deacetylase inhibitor phenylbutyrate on novel object recognition in zebrafish.

    Science.gov (United States)

    Faillace, M P; Pisera-Fuster, A; Medrano, M P; Bejarano, A C; Bernabeu, R O

    2017-03-01

    Zebrafish have a sophisticated color- and shape-sensitive visual system, so we examined color cue-based novel object recognition in zebrafish. We evaluated preference in the absence or presence of drugs that affect attention and memory retention in rodents: nicotine and the histone deacetylase inhibitor (HDACi) phenylbutyrate (PhB). The objective of this study was to evaluate whether nicotine and PhB affect innate preferences of zebrafish for familiar and novel objects after short- and long-retention intervals. We developed modified object recognition (OR) tasks using neutral novel and familiar objects in different colors. We also tested objects which differed with respect to the exploratory behavior they elicited from naïve zebrafish. Zebrafish showed an innate preference for exploring red or green objects rather than yellow or blue objects. Zebrafish were better at discriminating color changes than changes in object shape or size. Nicotine significantly enhanced or changed short-term innate novel object preference whereas PhB had similar effects when preference was assessed 24 h after training. Analysis of other zebrafish behaviors corroborated these results. Zebrafish were innately reluctant or prone to explore colored novel objects, so drug effects on innate preference for objects can be evaluated changing the color of objects with a simple geometry. Zebrafish exhibited recognition memory for novel objects with similar innate significance. Interestingly, nicotine and PhB significantly modified innate object preference.

  11. Sex specific response in cholesterol level in zebrafish (Danio rerio) after long-term exposure of difenoconazole

    International Nuclear Information System (INIS)

    Mu, Xiyan; Wang, Kai; Chai, Tingting; Zhu, Lizhen; Yang, Yang; Zhang, Jie; Pang, Sen; Wang, Chengju; Li, Xuefeng

    2015-01-01

    Difenoconazole is a widely used triazole fungicide, its extensive application may potentially cause toxic effects on non-target organisms. To investigate the effect of difenoconazole on cholesterol content and related mechanism, adult zebrafish were exposed to environmental related dosage (0.1, 10 and 500 μg/L) difenoconazole. The body weight and hepatic total cholesterol (TCHO) level was tested at 7, 15 and 30 days post exposure (dpe). The expressions of eight cholesterol synthesis genes and one cholesterol metabolism gene were assessed via Quantitative PCR method. The significant decrease of TCHO level in male zebrafish liver was observed at 15 and 30 dpe, which was accompanied by apparent hepatic cholesterol-genesis genes expression decline. In comparison with males, female zebrafish showed different transcription modification of tested genes, and the cholesterol content maintain normal level during the whole exposure. - Highlights: • Difenoconazle could reduce TCHO level in male zebrafish liver. • Difenoconazole could inhibit sterol-genesis genes expression in male zebrafish. • Female zebrafish didn't show obvious change of TCHO level after exposure. • Difenoconazole could inhibit body weight of both male and female zebrafish. - Difenoconazle could reduce cholesterol level and sterol-genesis genes expression in male zebrafish. While female zebrafish showed no obvious cholesterol content change during exposure

  12. Ginger Stimulates Hematopoiesis via Bmp Pathway in Zebrafish

    Science.gov (United States)

    Ferri-Lagneau, Karine F.; Moshal, Karni S.; Grimes, Matthew; Zahora, Braden; Lv, Lishuang; Sang, Shengmin; Leung, TinChung

    2012-01-01

    Background Anemia is a hematologic disorder with decreased number of erythrocytes. Erythropoiesis, the process by which red blood cells differentiate, are conserved in humans, mice and zebrafish. The only known agents available to treat pathological anemia are erythropoietin and its biologic derivatives. However, erythropoietin therapy elicits unwanted side-effects, high cost and intravenous or subcutaneous injection, warranting the development of a more cost effective and non-peptide alternative. Ginger (Zingiber officinale) has been widely used in traditional medicine; however, to date there is no scientific research documenting the potential of ginger to stimulate hematopoiesis. Methodology/Principal Findings Here, we utilized gata1:dsRed transgenic zebrafish embryos to investigate the effect of ginger extract on hematopoiesis in vivo and we identified its bioactive component, 10-gingerol. We confirmed that ginger and 10-gingerol promote the expression of gata1 in erythroid cells and increase the expression of hematopoietic progenitor markers cmyb and scl. We also demonstrated that ginger and 10-gingerol can promote the hematopoietic recovery from acute hemolytic anemia in zebrafish, by quantifying the number of circulating erythroid cells in the dorsal aorta using video microscopy. We found that ginger and 10-gingerol treatment during gastrulation results in an increase of bmp2b and bmp7a expression, and their downstream effectors, gata2 and eve1. At later stages ginger and 10-gingerol can induce bmp2b/7a, cmyb, scl and lmo2 expression in the caudal hematopoietic tissue area. We further confirmed that Bmp/Smad pathway mediates this hematopoiesis promoting effect of ginger by using the Bmp-activated Bmp type I receptor kinase inhibitors dorsomorphin, LND193189 and DMH1. Conclusions/Significance Our study provides a strong foundation to further evaluate the molecular mechanism of ginger and its bioactive components during hematopoiesis and to investigate their

  13. Dynamic transcriptomic profiles of zebrafish gills in response to zinc depletion

    Directory of Open Access Journals (Sweden)

    Cunningham Phil

    2010-10-01

    Full Text Available Abstract Background Zinc deficiency is detrimental to organisms, highlighting its role as an essential micronutrient contributing to numerous biological processes. To investigate the underlying molecular events invoked by zinc depletion we performed a temporal analysis of transcriptome changes observed within the zebrafish gill. This tissue represents a model system for studying ion absorption across polarised epithelial cells as it provides a major pathway for fish to acquire zinc directly from water whilst sharing a conserved zinc transporting system with mammals. Results Zebrafish were treated with either zinc-depleted (water = 2.61 μg L-1; diet = 26 mg kg-1 or zinc-adequate (water = 16.3 μg L-1; diet = 233 mg kg-1 conditions for two weeks. Gill samples were collected at five time points and transcriptome changes analysed in quintuplicate using a 16K oligonucleotide array. Of the genes represented the expression of a total of 333 transcripts showed differential regulation by zinc depletion (having a fold-change greater than 1.8 and an adjusted P-value less than 0.1, controlling for a 10% False Discovery Rate. Down-regulation was dominant at most time points and distinct sets of genes were regulated at different stages. Annotation enrichment analysis revealed that 'Developmental Process' was the most significantly overrepresented Biological Process GO term (P = 0.0006, involving 26% of all regulated genes. There was also significant bias for annotations relating to development, cell cycle, cell differentiation, gene regulation, butanoate metabolism, lysine degradation, protein tyrosin phosphatases, nucleobase, nucleoside and nucleotide metabolism, and cellular metabolic processes. Within these groupings genes associated with diabetes, bone/cartilage development, and ionocyte proliferation were especially notable. Network analysis of the temporal expression profile indicated that transcription factors foxl1, wt1, nr5a1, nr6a1, and especially

  14. A zebrafish larval model reveals early tissue-specific innate immune responses to Mucor circinelloides.

    Science.gov (United States)

    Voelz, Kerstin; Gratacap, Remi L; Wheeler, Robert T

    2015-11-01

    Mucormycosis is an emerging fungal infection that is clinically difficult to manage, with increasing incidence and extremely high mortality rates. Individuals with diabetes, suppressed immunity or traumatic injury are at increased risk of developing disease. These individuals often present with defects in phagocytic effector cell function. Research using mammalian models and phagocytic effector cell lines has attempted to decipher the importance of the innate immune system in host defence against mucormycosis. However, these model systems have not been satisfactory for direct analysis of the interaction between innate immune effector cells and infectious sporangiospores in vivo. Here, we report the first real-time in vivo analysis of the early innate immune response to mucormycete infection using a whole-animal zebrafish larval model system. We identified differential host susceptibility, dependent on the site of infection (hindbrain ventricle and swim bladder), as well as differential functions of the two major phagocyte effector cell types in response to viable and non-viable spores. Larval susceptibility to mucormycete spore infection was increased upon immunosuppressant treatment. We showed for the first time that macrophages and neutrophils were readily recruited in vivo to the site of infection in an intact host and that spore phagocytosis can be observed in real-time in vivo. While exploring innate immune effector recruitment dynamics, we discovered the formation of phagocyte clusters in response to fungal spores that potentially play a role in fungal spore dissemination. Spores failed to activate pro-inflammatory gene expression by 6 h post-infection in both infection models. After 24 h, induction of a pro-inflammatory response was observed only in hindbrain ventricle infections. Only a weak pro-inflammatory response was initiated after spore injection into the swim bladder during the same time frame. In the future, the zebrafish larva as a live whole

  15. Cardiac Myocyte Diversity and a Fibroblast Network in the Junctional Region of the Zebrafish Heart Revealed by Transmission and Serial Block-Face Scanning Electron Microscopy

    KAUST Repository

    Lafontant, Pascal J.; Behzad, Ali Reza; Brown, Evelyn; Landry, Paul; Hu, Norman; Burns, Alan R.

    2013-01-01

    The zebrafish has emerged as an important model of heart development and regeneration. While the structural characteristics of the developing and adult zebrafish ventricle have been previously studied, little attention has been paid to the nature

  16. Image-Based Measurement of H2O2 Reaction-Diffusion in Wounded Zebrafish Larvae.

    Science.gov (United States)

    Jelcic, Mark; Enyedi, Balázs; Xavier, João B; Niethammer, Philipp

    2017-05-09

    Epithelial injury induces rapid recruitment of antimicrobial leukocytes to the wound site. In zebrafish larvae, activation of the epithelial NADPH oxidase Duox at the wound margin is required early during this response. Before injury, leukocytes are near the vascular region, that is, ∼100-300 μm away from the injury site. How Duox establishes long-range signaling to leukocytes is unclear. We conceived that extracellular hydrogen peroxide (H 2 O 2 ) generated by Duox diffuses through the tissue to directly regulate chemotactic signaling in these cells. But before it can oxidize cellular proteins, H 2 O 2 must get past the antioxidant barriers that protect the cellular proteome. To test whether, or on which length scales this occurs during physiological wound signaling, we developed a computational method based on reaction-diffusion principles that infers H 2 O 2 degradation rates from intravital H 2 O 2 -biosensor imaging data. Our results indicate that at high tissue H 2 O 2 levels the peroxiredoxin-thioredoxin antioxidant chain becomes overwhelmed, and H 2 O 2 degradation stalls or ceases. Although the wound H 2 O 2 gradient reaches deep into the tissue, it likely overcomes antioxidant barriers only within ∼30 μm of the wound margin. Thus, Duox-mediated long-range signaling may require other spatial relay mechanisms besides extracellular H 2 O 2 diffusion. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. A novel mechanism for mechanosensory-based rheotaxis in larval zebrafish.

    Science.gov (United States)

    Oteiza, Pablo; Odstrcil, Iris; Lauder, George; Portugues, Ruben; Engert, Florian

    2017-07-27

    When flying or swimming, animals must adjust their own movement to compensate for displacements induced by the flow of the surrounding air or water. These flow-induced displacements can most easily be detected as visual whole-field motion with respect to the animal's frame of reference. Despite this, many aquatic animals consistently orient and swim against oncoming flows (a behaviour known as rheotaxis) even in the absence of visual cues. How animals achieve this task, and its underlying sensory basis, is still unknown. Here we show that, in the absence of visual information, larval zebrafish (Danio rerio) perform rheotaxis by using flow velocity gradients as navigational cues. We present behavioural data that support a novel algorithm based on such local velocity gradients that fish use to avoid getting dragged by flowing water. Specifically, we show that fish use their mechanosensory lateral line to first sense the curl (or vorticity) of the local velocity vector field to detect the presence of flow and, second, to measure its temporal change after swim bouts to deduce flow direction. These results reveal an elegant navigational strategy based on the sensing of flow velocity gradients and provide a comprehensive behavioural algorithm, also applicable for robotic design, that generalizes to a wide range of animal behaviours in moving fluids.

  18. Dopaminergic Neurons Controlling Anterior Pituitary Functions: Anatomy and Ontogenesis in Zebrafish.

    Science.gov (United States)

    Fontaine, Romain; Affaticati, Pierre; Bureau, Charlotte; Colin, Ingrid; Demarque, Michaël; Dufour, Sylvie; Vernier, Philippe; Yamamoto, Kei; Pasqualini, Catherine

    2015-08-01

    Dopaminergic (DA) neurons located in the preoptico-hypothalamic region of the brain exert a major neuroendocrine control on reproduction, growth, and homeostasis by regulating the secretion of anterior pituitary (or adenohypophysis) hormones. Here, using a retrograde tract tracing experiment, we identified the neurons playing this role in the zebrafish. The DA cells projecting directly to the anterior pituitary are localized in the most anteroventral part of the preoptic area, and we named them preoptico-hypophyseal DA (POHDA) neurons. During development, these neurons do not appear before 72 hours postfertilization (hpf) and are the last dopaminergic cell group to differentiate. We found that the number of neurons in this cell population continues to increase throughout life proportionally to the growth of the fish. 5-Bromo-2'-deoxyuridine incorporation analysis suggested that this increase is due to continuous neurogenesis and not due to a phenotypic change in already-existing neurons. Finally, expression profiles of several genes (foxg1a, dlx2a, and nr4a2a/b) were different in the POHDA compared with the adjacent suprachiasmatic DA neurons, suggesting that POHDA neurons develop as a distinct DA cell population in the preoptic area. This study offers some insights into the regional identity of the preoptic area and provides the first bases for future functional genetic studies on the development of DA neurons controlling anterior pituitary functions.

  19. Prey capture behaviour evoked by simple visual stimuli in larval zebrafish

    Directory of Open Access Journals (Sweden)

    Isaac Henry Bianco

    2011-12-01

    Full Text Available Understanding how the nervous system recognises salient stimuli in the environ- ment and selects and executes the appropriate behavioural responses is a fundamen- tal question in systems neuroscience. To facilitate the neuroethological study of visually-guided behaviour in larval zebrafish, we developed virtual reality assays in which precisely controlled visual cues can be presented to larvae whilst their behaviour is automatically monitored using machine-vision algorithms. Freely swimming larvae responded to moving stimuli in a size-dependent manner: they directed multiple low amplitude orienting turns (∼ 20◦ towards small moving spots (1◦ but reacted to larger spots (10◦ with high-amplitude aversive turns (∼ 60◦. The tracking of small spots led us to examine how larvae respond to prey during hunting routines. By analysing movie sequences of larvae hunting parame- cia, we discovered that all prey capture routines commence with eye convergence and larvae maintain their eyes in a highly converged position for the duration of the prey-tracking and capture swim phases. We adapted our virtual reality assay to deliver artificial visual cues to partially restrained larvae and found that small moving spots evoked convergent eye movements and J-turns of the tail, which are defining features of natural hunting. We propose that eye convergence represents the engagement of a predatory mode of behaviour in larval fish and serves to increase the region of binocular visual space to enable stereoscopic targeting of prey.

  20. Structural requirements for PACSIN/Syndapin operation during zebrafish embryonic notochord development.

    Science.gov (United States)

    Edeling, Melissa A; Sanker, Subramaniam; Shima, Takaki; Umasankar, P K; Höning, Stefan; Kim, Hye Y; Davidson, Lance A; Watkins, Simon C; Tsang, Michael; Owen, David J; Traub, Linton M

    2009-12-03

    PACSIN/Syndapin proteins are membrane-active scaffolds that participate in endocytosis. The structure of the Drosophila Syndapin N-terminal EFC domain reveals a crescent shaped antiparallel dimer with a high affinity for phosphoinositides and a unique membrane-inserting prong upon the concave surface. Combined structural, biochemical and reverse genetic approaches in zebrafish define an important role for Syndapin orthologue, Pacsin3, in the early formation of the notochord during embryonic development. In pacsin3-morphant embryos, midline convergence of notochord precursors is defective as axial mesodermal cells fail to polarize, migrate and differentiate properly. The pacsin3 morphant phenotype of a stunted body axis and contorted trunk is rescued by ectopic expression of Drosophila Syndapin, and depends critically on both the prong that protrudes from the surface of the bowed Syndapin EFC domain and the ability of the antiparallel dimer to bind tightly to phosphoinositides. Our data confirm linkage between directional migration, endocytosis and cell specification during embryonic morphogenesis and highlight a key role for Pacsin3 in this coupling in the notochord.

  1. Structural requirements for PACSIN/Syndapin operation during zebrafish embryonic notochord development.

    Directory of Open Access Journals (Sweden)

    Melissa A Edeling

    2009-12-01

    Full Text Available PACSIN/Syndapin proteins are membrane-active scaffolds that participate in endocytosis. The structure of the Drosophila Syndapin N-terminal EFC domain reveals a crescent shaped antiparallel dimer with a high affinity for phosphoinositides and a unique membrane-inserting prong upon the concave surface. Combined structural, biochemical and reverse genetic approaches in zebrafish define an important role for Syndapin orthologue, Pacsin3, in the early formation of the notochord during embryonic development. In pacsin3-morphant embryos, midline convergence of notochord precursors is defective as axial mesodermal cells fail to polarize, migrate and differentiate properly. The pacsin3 morphant phenotype of a stunted body axis and contorted trunk is rescued by ectopic expression of Drosophila Syndapin, and depends critically on both the prong that protrudes from the surface of the bowed Syndapin EFC domain and the ability of the antiparallel dimer to bind tightly to phosphoinositides. Our data confirm linkage between directional migration, endocytosis and cell specification during embryonic morphogenesis and highlight a key role for Pacsin3 in this coupling in the notochord.

  2. Leptospira interrogans stably infects zebrafish embryos, altering phagocyte behavior and homing to specific tissues.

    Directory of Open Access Journals (Sweden)

    J Muse Davis

    2009-06-01

    Full Text Available Leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal Weil's syndrome. Despite the global impact of the disease, key aspects of its pathogenesis remain unclear. To examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled Leptospira interrogans serovar Copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. These embryos have functional innate immunity but have not yet developed an adaptive immune system. Furthermore, they are optically transparent, allowing direct visualization of host-pathogen interactions from the moment of infection. We observed rapid uptake of leptospires by phagocytes, followed by persistent, intracellular infection over the first 48 hours. Phagocytosis of leptospires occasionally resulted in formation of large cellular vesicles consistent with apoptotic bodies. By 24 hours, clusters of infected phagocytes were accumulating lateral to the dorsal artery, presumably in early hematopoietic tissue. Our observations suggest that phagocytosis may be a key defense mechanism in the early stages of leptospirosis, and that phagocytic cells play roles in immunopathogenesis and likely in the dissemination of leptospires to specific target tissues.

  3. Novel expression patterns of metabotropic glutamate receptor 6 in the zebrafish nervous system.

    Directory of Open Access Journals (Sweden)

    Ying-Yu Huang

    Full Text Available The metabotropic glutamate receptor 6 (mGluR6 or GRM6 belongs to the class III of the metabotropic glutamate receptor family. It is the only known mGluR that mediates direct synaptic transmission in the nervous system and is thought to mediate the ON-response in the ON-pathway of the vertebrate retina. Phylogenetic and gene structure analysis indicated that the zebrafish genome harbours two mglur6 paralogs, mglur6a and mglur6b. Besides expression in the inner nuclear layer and distinct regions in the brain, both mglur6 paralogs are expressed in ganglion cells of the retina, an expression pattern which can also be observed in the downstream effector molecules gnaoa and gnaob. This unexpected expression pattern is consistent with immunohistological labeling using a peptide antibody specific for the mGluR6b paralog. These expression patterns contradict the existing view that mGluR6 is solely located on ON-bipolar cells where it functions in signal transmission. Consistent with expression in ON-bipolar cells, we report a decreased b-wave amplitude in the electroretinogram after morpholino-based downregulation of mGluR6b, showing a function in the ON response. Our data suggest more widespread functions of mGluR6 mediated signaling in the central nervous system, possibly including sign reversing synapses in the inner retina.

  4. Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration.

    Science.gov (United States)

    Lee, Sang Goo; Huang, Mingqian; Obholzer, Nikolaus D; Sun, Shan; Li, Wenyan; Petrillo, Marco; Dai, Pu; Zhou, Yi; Cotanche, Douglas A; Megason, Sean G; Li, Huawei; Chen, Zheng-Yi

    2016-01-01

    Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration.

  5. 10th European Zebrafish Meeting 2017, Budapest: Husbandry Workshop Summary.

    Science.gov (United States)

    Oltová, Jana; Barton, Carrie; Certal, Ana Catarina; Argenton, Francesco; Varga, Zoltán M

    2018-01-02

    A husbandry workshop on July 3, 2017, at the 10th European Zebrafish Meeting in Budapest, Hungary (July 3-July 7, 2017), focused on the standardization, optimization, and streamlining of fish facility procedures. Standardization can be achieved for example by developing novel software and hardware tools, such as a fish facility database for husbandry and environmental facility management (Zebrabase, Oltova), or a hand-held, air-pressurized fish feeder for consistent food distribution (Blowfish, Argenton). Streamlining is achieved when work hours are reduced, as with the standardized fish feeder, or by limiting the number and types of fish diets and observing the effect on animal welfare and performance (Barton). Testing the characteristics of new fish diets and observing whether they produce better experimental outcomes (Certal) optimizes diets and improves fish productivity. Collectively, the workshop presentations emphasized how consistency and harmonization of husbandry procedures within and across aquatic facilities yield reproducible scientific outcomes.

  6. Brain-wide neuronal dynamics during motor adaptation in zebrafish.

    Science.gov (United States)

    Ahrens, Misha B; Li, Jennifer M; Orger, Michael B; Robson, Drew N; Schier, Alexander F; Engert, Florian; Portugues, Ruben

    2012-05-09

    A fundamental question in neuroscience is how entire neural circuits generate behaviour and adapt it to changes in sensory feedback. Here we use two-photon calcium imaging to record the activity of large populations of neurons at the cellular level, throughout the brain of larval zebrafish expressing a genetically encoded calcium sensor, while the paralysed animals interact fictively with a virtual environment and rapidly adapt their motor output to changes in visual feedback. We decompose the network dynamics involved in adaptive locomotion into four types of neuronal response properties, and provide anatomical maps of the corresponding sites. A subset of these signals occurred during behavioural adjustments and are candidates for the functional elements that drive motor learning. Lesions to the inferior olive indicate a specific functional role for olivocerebellar circuitry in adaptive locomotion. This study enables the analysis of brain-wide dynamics at single-cell resolution during behaviour.

  7. Inexhaustible hair-cell regeneration in young and aged zebrafish

    Directory of Open Access Journals (Sweden)

    Filipe Pinto-Teixeira

    2015-07-01

    Full Text Available Animals have evolved two general strategies to counter injury and maintain physiological function. The most prevalent is protection by isolating vital organs into body cavities. However, protection is not optimal for sensory systems because their external components need to be exposed to the environment to fulfill their receptive function. Thus, a common strategy to maintain sensory abilities against persistent environmental insult involves repair and regeneration. However, whether age or frequent injuries affect the regenerative capacity of sensory organs remains unknown. We have found that neuromasts of the zebrafish lateral line regenerate mechanosensory hair cells after recurrent severe injuries and in adulthood. Moreover, neuromasts can reverse transient imbalances of Notch signaling that result in defective organ proportions during repair. Our results reveal inextinguishable hair-cell regeneration in the lateral line, and suggest that the neuromast epithelium is formed by plastic territories that are maintained by continuous intercellular communication.

  8. Myosin phosphatase Fine-tunes Zebrafish Motoneuron Position during Axonogenesis.

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    Juliane Bremer

    2016-11-01

    Full Text Available During embryogenesis the spinal cord shifts position along the anterior-posterior axis relative to adjacent tissues. How motor neurons whose cell bodies are located in the spinal cord while their axons reside in adjacent tissues compensate for such tissue shift is not well understood. Using live cell imaging in zebrafish, we show that as motor axons exit from the spinal cord and extend through extracellular matrix produced by adjacent notochord cells, these cells shift several cell diameters caudally. Despite this pronounced shift, individual motoneuron cell bodies stay aligned with their extending axons. We find that this alignment requires myosin phosphatase activity within motoneurons, and that mutations in the myosin phosphatase subunit mypt1 increase myosin phosphorylation causing a displacement between motoneuron cell bodies and their axons. Thus, we demonstrate that spinal motoneurons fine-tune their position during axonogenesis and we identify the myosin II regulatory network as a key regulator.

  9. Imaging retinal progenitor lineages in developing zebrafish embryos.

    Science.gov (United States)

    Jusuf, Patricia; Harris, William A; Poggi, Lucia

    2013-03-01

    In this protocol, we describe how to make and analyze four dimensional (4D) movies of retinal lineage in the zebrafish embryo in vivo. 4D consists of three spatial dimensions (3D) reconstructed from stacks of confocal planes plus one time dimension. Our imaging is performed on transgenic cells that express fluorescent proteins under the control of cell-specific promoters or on cells that transiently express such reporters in specific retinal cell progenitors. An important aspect of lineage tracing is the ability to follow individual cells as they undergo multiple cell divisions, final migration, and differentiation. This may mean many hours of 4D imaging, requiring that cells be kept healthy and maintained under conditions suitable for normal development. The longest movies we have made are ∼50 h. By analyzing these movies, we can see when a specific cell was born and who its sister was, allowing us to reconstruct its retinal lineages in vivo.

  10. mc1r Pathway regulation of zebrafish melanosome dispersion

    DEFF Research Database (Denmark)

    Richardson, Jennifer; Lundegaard, Pia Rengtved; Reynolds, Natalie L

    2008-01-01

    Zebrafish rapidly alter their pigmentation in response to environmental changes. For black melanocytes, this change is due to aggregation or dispersion of melanin in the cell. Dispersion and aggregation are controlled by intracellular cyclic adenosine monophosphate (cAMP) levels, which increase...... in mammals, and melanosome dispersal in cold-blood vertebrates, the pathway components are highly conserved. However, it has only been assumed that mc1r mediates melanosome dispersal in fish. Here, using morpholino oligonucleotides designed to knockdown mc1r expression, we find that mc1r morphants are unable...... to disperse melanosomes when grown in dark conditions. We also use chemical modifiers of the cAMP pathway, and find an unexpected response to the specific phosphodiesterase 4 (PDE4) inhibitor, rolipram, in melanosome dispersal. When treated with the drug, melanosomes fail to fully disperse in dark conditions...

  11. In vivo wall shear measurements within the developing zebrafish heart.

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    R Aidan Jamison

    Full Text Available Physical forces can influence the embryonic development of many tissues. Within the cardiovascular system shear forces resulting from blood flow are known to be one of the regulatory signals that shape the developing heart. A key challenge in investigating the role of shear forces in cardiac development is the ability to obtain shear force measurements in vivo. Utilising the zebrafish model system we have developed a methodology that allows the shear force within the developing embryonic heart to be determined. Accurate wall shear measurement requires two essential pieces of information; high-resolution velocity measurements near the heart wall and the location and orientation of the heart wall itself. We have applied high-speed brightfield imaging to capture time-lapse series of blood flow within the beating heart between 3 and 6 days post-fertilization. Cardiac-phase filtering is applied to these time-lapse images to remove the heart wall and other slow moving structures leaving only the red blood cell movement. Using particle image velocimetry to calculate the velocity of red blood cells in different regions within the heart, and using the signal-to-noise ratio of the cardiac-phase filtered images to determine the boundary of blood flow, and therefore the position of the heart wall, we have been able to generate the necessary information to measure wall shear in vivo. We describe the methodology required to measure shear in vivo and the application of this technique to the developing zebrafish heart. We identify a reduction in shear at the ventricular-bulbar valve between 3 and 6 days post-fertilization and demonstrate that the shear environment of the ventricle during systole is constantly developing towards a more uniform level.