Science.gov

Sample records for models zebrafish medaka

  1. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry

    PubMed Central

    Signore, Iskra A.; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L.

    2008-01-01

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115–200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal–habenular–interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left–right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates. PMID:19064351

  2. Zebrafish and medaka: model organisms for a comparative developmental approach of brain asymmetry.

    PubMed

    Signore, Iskra A; Guerrero, Néstor; Loosli, Felix; Colombo, Alicia; Villalón, Aldo; Wittbrodt, Joachim; Concha, Miguel L

    2009-04-12

    Comparison between related species is a successful approach to uncover conserved and divergent principles of development. Here, we studied the pattern of epithalamic asymmetry in zebrafish (Danio rerio) and medaka (Oryzias latipes), two related teleost species with 115-200 Myr of independent evolution. We found that these species share a strikingly conserved overall pattern of asymmetry in the parapineal-habenular-interpeduncular system. Nodal signalling exhibits comparable spatial and temporal asymmetric expressions in the presumptive epithalamus preceding the development of morphological asymmetries. Neuroanatomical asymmetries consist of left-sided asymmetric positioning and connectivity of the parapineal organ, enlargement of neuropil in the left habenula compared with the right habenula and segregation of left-right habenular efferents along the dorsoventral axis of the interpeduncular nucleus. Despite the overall conservation of asymmetry, we observed heterotopic changes in the topology of parapineal efferent connectivity, heterochronic shifts in the timing of developmental events underlying the establishment of asymmetry and divergent degrees of canalization of embryo laterality. We offer new tools for developmental time comparison among species and propose, for each of these transformations, novel hypotheses of ontogenic mechanisms that explain interspecies variations that can be tested experimentally. Together, these findings highlight the usefulness of zebrafish and medaka as comparative models to study the developmental mechanisms of epithalamic asymmetry in vertebrates.

  3. Current Status of Sperm Cryopreservation in Biomedical Research Fish Models: Zebrafish, Medaka, and Xiphophorus*

    PubMed Central

    Yang, Huiping; Tiersch, Terrence R.

    2009-01-01

    Aquarium fishes are becoming increasingly important because of their value in biomedical research and the ornamental fish trade, and because many have become threatened or endangered in the wild. This review summarizes the current status of sperm cryopreservation in three fishes widely used in biomedical research: zebrafish, medaka, and live-bearing fishes of the genus Xiphophorus, and will focus on the needs and opportunities for future research and application of cryopreservation in aquarium fish. First, we summarize the basic biological characteristics regarding natural habitat, testis structure, spermatogenesis, sperm morphology, and sperm physiology. Second, we compare protocol development of sperm cryopreservation. Third, we emphasize the importance of artificial fertilization in sperm cryopreservation to evaluate the viability of thawed sperm. We conclude with a look to future research directions for sperm cryopreservation and the application of this technique in aquarium species. PMID:18691673

  4. A Comparative Analysis of Glomerulus Development in the Pronephros of Medaka and Zebrafish

    PubMed Central

    Ichimura, Koichiro; Bubenshchikova, Ekaterina; Powell, Rebecca; Fukuyo, Yayoi; Nakamura, Tomomi; Tran, Uyen; Oda, Shoji; Tanaka, Minoru; Wessely, Oliver; Kurihara, Hidetake; Sakai, Tatsuo; Obara, Tomoko

    2012-01-01

    The glomerulus of the vertebrate kidney links the vasculature to the excretory system and produces the primary urine. It is a component of every single nephron in the complex mammalian metanephros and also in the primitive pronephros of fish and amphibian larvae. This systematic work highlights the benefits of using teleost models to understand the pronephric glomerulus development. The morphological processes forming the pronephric glomerulus are astoundingly different between medaka and zebrafish. (1) The glomerular primordium of medaka - unlike the one of zebrafish - exhibits a C-shaped epithelial layer. (2) The C-shaped primordium contains a characteristic balloon-like capillary, which is subsequently divided into several smaller capillaries. (3) In zebrafish, the bilateral pair of pronephric glomeruli is fused at the midline to form a glomerulus, while in medaka the two parts remain unmerged due to the interposition of the interglomerular mesangium. (4) Throughout pronephric development the interglomerular mesangial cells exhibit numerous cytoplasmic granules, which are reminiscent of renin-producing (juxtaglomerular) cells in the mammalian afferent arterioles. Our systematic analysis of medaka and zebrafish demonstrates that in fish, the morphogenesis of the pronephric glomerulus is not stereotypical. These differences need be taken into account in future analyses of medaka mutants with glomerulus defects. PMID:23028906

  5. Interordinal chimera formation between medaka and zebrafish for analyzing stem cell differentiation.

    PubMed

    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.

  6. Colored medaka and zebrafish: transgenics with ubiquitous and strong transgene expression driven by the medaka β-actin promoter.

    PubMed

    Yoshinari, Nozomi; Ando, Kazunori; Kudo, Akira; Kinoshita, Masato; Kawakami, Atsushi

    2012-12-01

    Conditional cell labeling, cell tracing, and genetic manipulation approaches are becoming increasingly important in developmental and regenerative biology. Such approaches in zebrafish research are hampered by the lack of an ubiquitous transgene driver element that is active at all developmental stages. Here, we report the isolation and characterization of the medaka fish (Oryzias latipes) β-actin (Olactb) promoter, which drives constitutive transgene expression during all developmental stages, and the analysis of adult organs except blood cell types. Taking advantage of the compact medaka promoter, we succeeded in generating a zebrafish transgenic (Tg) line with unprecedentedly strong and widespread transgene expression from embryonic to adult stages. Moreover, the Tg carries a pair of loxP sites, which enables the reporter fluorophore to switch from DsRed2 to enhanced green fluorescent protein (EGFP). We induced Cre/loxP recombination with Tg(hsp70l: mCherry-t2a-Cre(ERt2) ) in the double Tg embryo and generated a Tg line that constitutively expresses EGFP. We further demonstrate the powerful application of Olactb-driven Tgs for cell lineage tracing using transplantation experiments with embryonic cells at the shield stage and adult cells of regenerating fin. Thus, the use of promoter elements from medaka is an alternative approach to generate Tgs with stronger and even novel expression patterns in zebrafish. The Olactb promoter and the Tg lines presented here represent an important advancement for the broader use of Cre/loxP-based Tg applications in zebrafish. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  7. Development of a transient expression assay for detecting environmental oestrogens in zebrafish and medaka embryos

    PubMed Central

    2012-01-01

    our construct works in medaka, another model fish test species, suggesting the transient assay is applicable for testing oestrogenic chemicals in fish generally. Conclusion Our results indicate that the transient expression assay system can be used as a rapid integrated testing system for environmental oestrogens and to detect the oestrogenic target sites in developing fish embryos. PMID:22726887

  8. Conservation of Skeletal Regulators in the Fish Model Medaka (Oryzias latipes)

    NASA Astrophysics Data System (ADS)

    Wagner, T.; Renn, J.; Koester, R.; Goerlich, R.; Schartl, M.; Winkler, C.

    Small aquarium fish species, like the well known zebrafish (Danio rerio) and the related Medaka (Oryzias latipes) represent vertebrate models that offer many advantages to study biomineralization in vivo. These fish produce large numbers of completely transparent embryos, thus allowing real-time analysis of skeletal development in living specimens. Using the calcium-binding fluorochrome Calcein and confocal laser scanning microscopy in Medaka, we followed the formation of calcified bone from day 6 of embryonic development until day 20 post hatching. To establish fish as models for human bone disease, we furthermore isolated 11 genes in medaka, the orthologs of which are known to be important regulators of osteoblast, osteoclast and chondrocyte formation in human. We show that these genes are highly conserved between fish and mammals in both sequence and expression pattern. This includes osteonectin, the major non-collagenous component of the mammalian bone matrix. Medaka osteonectin is expressed in osteoblasts and chondrocytes, e.g. in the developing vertebrae. For functional characterization of all these skeletal factors, they are ectopically expressed after gene transfer into fish embryos and their effect on bone formation is analyzed by Calcein staining in developing fish in vivo. Alternatively, the activity of these factors can be blocked by antisense oligonucleotide mediated gene knock-down. In addition, the Medaka offers the unique opportunity to study biomineralization processes in fish in vitro by using embryonic stem (ES) cells. In an approach to study calcification events at the cellular level, candidate genes will be ectopically expressed in these ES cells, thereby driving differentiation of stem cells into the osteoblast lineage. Acknowledgement: This work is supported by the German Aerospace Center (DLR) (50 WB 0152) and the European Space Agency (AO-LS-99-MAP-LSS-003).

  9. Spatio-temporal Features of Neurogenesis in the Retina of Medaka, Oryzias latipes

    PubMed Central

    Kitambi, Satish S.; Malicki, Jarema J.

    2010-01-01

    The vertebrate retina is very well conserved in evolution. Its structure and functional features are very similar in phyla as different as primates and teleost fish. Here we describe the spatio-temporal characteristics of neurogenesis in the retina of a teleost, medaka, and compare them to other species, primarily the zebrafish. Several intriguing differences are observed between medaka and zebrafish. For example, photoreceptor differentiation in the medaka retina starts independently in two different areas, and at more advanced stages of differentiation, medaka and zebrafish retinae display obviously different patterns of the photoreceptor cell mosaic. Medaka and zebrafish evolutionary lineages are thought to have separated from each other 110 million years ago, and so the differences between these species are not unexpected, and may be exploited to gain insight into the architecture of developmental pathways. Importantly, this work highlights the benefits of using multiple teleost models in parallel to understand a developmental process. PMID:19035349

  10. Dechorionation of medaka embryos and cell transplantation for the generation of chimeras.

    PubMed

    Porazinski, Sean R; Wang, Huijia; Furutani-Seiki, Makoto

    2010-12-22

    Medaka is a small egg-laying freshwater fish that allows both genetic and embryological analyses and is one of the three vertebrate model organisms in which genome-wide phenotype-driven mutant screens were carried out (1). Divergence of functional overlap of related genes between medaka and zebrafish allows identification of novel phenotypes that are unidentifiable in a single species (2), thus medaka and zebrafish are complementary for genetic dissection of the vertebrate genome functions. Manipulation of medaka embryos, such as dechorionation, mounting embryos for imaging and cell transplantation, are key procedures to work on both medaka and zebrafish in a laboratory. Cell transplantation examines cell autonomy of medaka mutations. Chimeras are generated by transplanting labeled cells from donor embryos into unlabeled recipient embryos. Donor cells can be transplanted to specific areas of the recipient embryos based on the fate maps (3) so that clones from transplanted cells can be integrated in the tissue of interest during development. Due to the hard chorion and soft embryos, manipulation of medaka embryos is more involved than in zebrafish. In this video, we show detailed procedures to manipulate medaka embryos.

  11. Beyond the zebrafish: diverse fish species for modeling human disease

    PubMed Central

    Schartl, Manfred

    2014-01-01

    ABSTRACT In recent years, zebrafish, and to a lesser extent medaka, have become widely used small animal models for human diseases. These organisms have convincingly demonstrated the usefulness of fish for improving our understanding of the molecular and cellular mechanisms leading to pathological conditions, and for the development of new diagnostic and therapeutic tools. Despite the usefulness of zebrafish and medaka in the investigation of a wide spectrum of traits, there is evidence to suggest that other fish species could be better suited for more targeted questions. With the emergence of new, improved sequencing technologies that enable genomic resources to be generated with increasing efficiency and speed, the potential of non-mainstream fish species as disease models can now be explored. A key feature of these fish species is that the pathological condition that they model is often related to specific evolutionary adaptations. By exploring these adaptations, new disease-causing and disease-modifier genes might be identified; thus, diverse fish species could be exploited to better understand the complexity of disease processes. In addition, non-mainstream fish models could allow us to study the impact of environmental factors, as well as genetic variation, on complex disease phenotypes. This Review will discuss the opportunities that such fish models offer for current and future biomedical research. PMID:24271780

  12. The see-through medaka: a fish model that is transparent throughout life.

    PubMed

    Wakamatsu, Y; Pristyazhnyuk, S; Kinoshita, M; Tanaka, M; Ozato, K

    2001-08-28

    The see-through medaka is a vertebrate model with a transparent body in the adult stage, as well as during the embryonic stages, that was generated from a small laboratory fish, medaka (Oryzias latipes). In this fish model, most of the pigments are genetically removed from the entire body by a combination of recessive alleles at four loci. The main internal organs, namely, heart, spleen, blood vessels, liver, gut, gonads, kidney, brain, spinal cord, lens, air bladder, and gills, in living adult fish are visible to the naked eye or with a simple stereoscopic microscope. This fish is healthy and fertile. A transgenic see-through medaka was produced by using the green fluorescent protein (GFP) gene fused to the regulatory regions of the medaka vasa gene, in which germ cell-specific expression of GFP was visualized. The fluorescent tag also efficiently improved visibility of gonadal tissues. The process of oocyte maturation in the ovary was monitored by repeated observations from the outside of the body during one spawning cycle in the same living females of the transgenic see-through stock. The see-through medaka will provide an opportunity for noninvasive studies of morphological and molecular events that occur in internal organs in the later stages of life.

  13. Viable Neuronopathic Gaucher Disease Model in Medaka (Oryzias latipes) Displays Axonal Accumulation of Alpha-Synuclein

    PubMed Central

    Uemura, Norihito; Koike, Masato; Ansai, Satoshi; Kinoshita, Masato; Ishikawa-Fujiwara, Tomoko; Matsui, Hideaki; Naruse, Kiyoshi; Sakamoto, Naoaki; Uchiyama, Yasuo; Todo, Takeshi; Takeda, Shunichi; Yamakado, Hodaka; Takahashi, Ryosuke

    2015-01-01

    Homozygous mutations in the glucocerebrosidase (GBA) gene result in Gaucher disease (GD), the most common lysosomal storage disease. Recent genetic studies have revealed that GBA mutations confer a strong risk for sporadic Parkinson’s disease (PD). To investigate how GBA mutations cause PD, we generated GBA nonsense mutant (GBA-/-) medaka that are completely deficient in glucocerebrosidase (GCase) activity. In contrast to the perinatal death in humans and mice lacking GCase activity, GBA-/- medaka survived for months, enabling analysis of the pathological progression. GBA-/- medaka displayed the pathological phenotypes resembling human neuronopathic GD including infiltration of Gaucher cell-like cells into the brains, progressive neuronal loss, and microgliosis. Detailed pathological findings represented lysosomal abnormalities in neurons and alpha-synuclein (α-syn) accumulation in axonal swellings containing autophagosomes. Unexpectedly, disruption of α-syn did not improve the life span, formation of axonal swellings, neuronal loss, or neuroinflammation in GBA-/- medaka. Taken together, the present study revealed GBA-/- medaka as a novel neuronopathic GD model, the pahological mechanisms of α-syn accumulation caused by GCase deficiency, and the minimal contribution of α-syn to the pathogenesis of neuronopathic GD. PMID:25835295

  14. Effects of propranolol on heart rate and development in Japanese medaka (Oryzias latipes) and zebrafish (Danio rerio).

    PubMed

    Finn, Juliane; Hui, Michelle; Li, Vincent; Lorenzi, Varenka; de la Paz, Nayeli; Cheng, Shuk Han; Lai-Chan, Leo; Schlenk, Daniel

    2012-10-15

    Propranolol is a β-adrenergic receptor antagonist (β-blocker) that is frequently used to treat hypertension and other cardiovascular conditions in humans. Detected in surface waters due to discharge of domestic wastewater, propranolol has demonstrated significant species differences in toxicity between fish. The aim of this study was to investigate the effects of propranolol on heart rate and development in embryos of two species of fish; Japanese medaka (JM) Oryzias latipes and zebrafish (ZF) Danio rerio. Parents and fertilized embryos of each species were exposed to nominal (measured) concentrations of 0.1 (0.09), 1 (1.1) and 10 (8.3) μg/L of propranolol. Heart rate was monitored during subsequent exposure in embryos at incremental developmental periods (44, 54, 64 h post-fertilization (hpf) for ZF and 68, 116, 164 hpf for JM). Heart development and morphology was examined using whole mount immunostaining with distance measurements between the sinus venosus (SV) and bulbus arteriosis (BV). Morphological measurements were made at 44 hpf for ZF and 164 hpf for JM. In ZF, a significant reduction in heart rate was observed at 0.08 μg/L propranolol, along with an increase in the SV-BA distance at 44 hpf. Significant reductions in heart rate were also observed in ZF at 54 and 64 hpf at all concentrations of propranolol. For JM, heart rates generally decreased at all developmental timepoints (68, 116 and 164 hpf) after propranolol treatment, with concentration dependent decreases observed at 164 hpf and a lowest observed effect concentration (LOEC) of 0.09 μg/L propranolol at each timepoint. However, significant alterations in cardiac morphology were not observed in JM at 164 hpf. In contrast, heart rates and morphology in ZF were affected with a non-monotonic concentration response in morphology and a LOEC of 0.09 μg/L propranolol for morphological alterations at 44 hpf and for heart rate at each timepoint. These data indicated unique developmental stages of

  15. Conspecific injury raises an alarm in medaka

    PubMed Central

    Mathuru, Ajay S.

    2016-01-01

    In the late 1930s, Karl von Frisch reported that semiochemicals released upon injury, act as alarm substances (Schreckstoff) in fish. In Ostariophysi species, club cells in the epidermis are believed to contain cues related to alarm substance; however, the function of club cells, primarily as reservoirs of alarm substance has been debated. Here, I describe an alarm response in the Japanese rice fish Oryzias latipes (medaka), a member of the order Beloniformes. The response to alarm substance (Schreckreaction) in medaka is characterized by bouts of immobility and an increase in cortisol levels within minutes of exposure to conspecific skin extract. Histological analysis, however, suggests that club cells are either rare or absent in the medaka epidermis. In addition to describing an uncharacterized behavior in a vertebrate popular for genetic and developmental studies, these results support the hypothesis that the primary function of epidermal club cells may be unrelated to a role as alarm substance cells. The existence of similar behavioral responses in two evolutionarily distant but well established laboratory models, the zebrafish and the medaka, offers the possibility of comparative analyses of neural circuits encoding innate fear. PMID:27824153

  16. In vivo Magnetic Resonance Microscopy and Hypothermic Anaesthesia of a Disease Model in Medaka

    PubMed Central

    Ueno, Tomohiro; Suzuki, Hirokazu; Hiraishi, Masahiro; Amano, Hideaki; Fukuyama, Hidenao; Sugimoto, Naozo

    2016-01-01

    In medical and pharmacological research, various human disease models in small fish, such as medaka (Oryzias latipes), have been created. To investigate these disease models noninvasively, magnetic resonance imaging (MRI) is suitable because these small fish are no longer transparent as adults. However, their small body size requires a high spatial resolution, and a water pool should be avoided to maximize the strength of MRI. We developed in vivo magnetic resonance microscopy (MR microscopy) without a water pool by combining hypothermic anaesthesia and a 14.1 T MR microscope. Using in vivo MR microscopy, we noninvasively evaluated the hepatic steatosis level of a non-alcoholic fatty liver disease model in medaka and followed the individual disease progression. The steatosis level was quantified by the MRI-estimated proton density fat-fraction (MRI-PDFF), which estimates the triglyceride fat concentration in liver tissue and is recognized as an imaging biomarker. The MRI-PDFF results agreed with a histological analysis. Moreover, we optimized the hypothermic anaesthesia procedure to obtain a recovery proportion of 1 in the experiment involving MR microscopy. Recovered medaka could not be distinguished from naïve medaka after the experiment. Therefore, the in vivo MR microscopy will expand the possibilities of a human disease model in fish. PMID:27251889

  17. Generation and Characterization of Neurogeninl-GFP Transgenic Medaka for High Throughput Developmental Neurotoxicity Screening

    EPA Science Inventory

    Fish models such as zebrafish and medaka are increasingly used as alternatives to rodents in developmental and toxicological studies. These developmental and toxicological studies can be facilitated by the use of transgenic reporters that permit the real-time, noninvasive observa...

  18. MEPD: medaka expression pattern database, genes and more

    PubMed Central

    Alonso-Barba, Juan I.; Rahman, Raza-Ur; Wittbrodt, Joachim; Mateo, Juan L.

    2016-01-01

    The Medaka Expression Pattern Database (MEPD; http://mepd.cos.uni-heidelberg.de/) is designed as a repository of medaka expression data for the scientific community. In this update we present two main improvements. First, we have changed the previous clone-centric view for in situ data to a gene-centric view. This is possible because now we have linked all the data present in MEPD to the medaka gene annotation in ENSEMBL. In addition, we have also connected the medaka genes in MEPD to their corresponding orthologous gene in zebrafish, again using the ENSEMBL database. Based on this, we provide a link to the Zebrafish Model Organism Database (ZFIN) to allow researches to compare expression data between these two fish model organisms. As a second major improvement, we have modified the design of the database to enable it to host regulatory elements, promoters or enhancers, expression patterns in addition to gene expression. The combination of gene expression, by traditional in situ, and regulatory element expression, typically by fluorescence reporter gene, within the same platform assures consistency in terms of annotation. In our opinion, this will allow researchers to uncover new insights between the expression domain of genes and their regulatory landscape. PMID:26450962

  19. Molecular Analysis of Medaka Tumors: New Models for Carcinogenicity Testing

    DTIC Science & Technology

    1992-07-06

    Medaka can be induced to breed year round, provide large numbers of eggs and are easy to culture . Induction of tumors has been reported in nearly every... culture of pSV neo in pBR322 was obtained and plasmid DNA was isolated on a CsCl gradient. This DNA will be used to continue the screening of the genomic...methylazoxymethanol acetate in the guppy Poecilia reticulata. JNCI 78:715-725. Graham, F.L. and van der Eb, A.J. 1973. A new technique for the assay of

  20. Inflammatory diseases modelling in zebrafish

    PubMed Central

    Morales Fénero, Camila Idelí; Colombo Flores, Alicia Angelina; Câmara, Niels Olsen Saraiva

    2016-01-01

    The ingest of diets with high content of fats and carbohydrates, low or no physical exercise and a stressful routine are part of the everyday lifestyle of most people in the western world. These conditions are triggers for different diseases with complex interactions between the host genetics, the metabolism, the immune system and the microbiota, including inflammatory bowel diseases (IBD), obesity and diabetes. The incidence of these disorders is growing worldwide; therefore, new strategies for its study are needed. Nowadays, the majority of researches are in use of murine models for understand the genetics, physiopathology and interaction between cells and signaling pathways to find therapeutic solutions to these diseases. The zebrafish, a little tropical water fish, shares 70% of our genes and conserves anatomic and physiological characteristics, as well as metabolical pathways, with mammals, and is rising as a new complementary model for the study of metabolic and inflammatory diseases. Its high fecundity, fast development, transparency, versatility and low cost of maintenance makes the zebrafish an interesting option for new researches. In this review, we offer a discussion of the existing genetic and induced zebrafish models of two important Western diseases that have a strong inflammatory component, the IBD and the obesity. PMID:26929916

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

    PubMed

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

    2012-06-01

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

  2. Animal Models of Tuberculosis: Zebrafish

    PubMed Central

    van Leeuwen, Lisanne M.; van der Sar, Astrid M.; Bitter, Wilbert

    2015-01-01

    Over the past decade the zebrafish (Danio rerio) has become an attractive new vertebrate model organism for studying mycobacterial pathogenesis. The combination of medium-throughput screening and real-time in vivo visualization has allowed new ways to dissect host pathogenic interaction in a vertebrate host. Furthermore, genetic screens on the host and bacterial sides have elucidated new mechanisms involved in the initiation of granuloma formation and the importance of a balanced immune response for control of mycobacterial pathogens. This article will highlight the unique features of the zebrafish–Mycobacterium marinum infection model and its added value for tuberculosis research. PMID:25414379

  3. Zebrafish as a model for human osteosarcoma.

    PubMed

    Mohseny, A B; Hogendoorn, P C W

    2014-01-01

    For various reasons involving biological comparativeness, expansive technological possibilities, accelerated experimental speed, and competitive costs, zebrafish has become a comprehensive model for cancer research. Hence, zebrafish embryos and full-grown fish have been instrumental for studies of leukemia, melanoma, pancreatic cancer, bone tumors, and other malignancies. Although because of its similarities to human osteogenesis zebrafish appears to be an appealing model to investigate osteosarcoma, only a few osteosarcoma specific studies have been accomplished yet. Here, we review interesting related and unrelated reports of which the findings might be extrapolated to osteosarcoma. More importantly, rational but yet unexplored applications of zebrafish are debated to expand the window of opportunities for future establishment of osteosarcoma models. Accordingly technological advances of zebrafish based cancer research, such as robotic high-throughput multicolor injection systems and advanced imaging methods are discussed. Furthermore, various use of zebrafish embryos for screening drug regimens by combinations of chemotherapy, novel drug deliverers, and immune system modulators are suggested. Concerning the etiology, the high degree of genetic similarity between zebrafish and human cancers indicates that affected regions are evolutionarily conserved. Therefore, zebrafish as a swift model system that allows for the investigation of multiple candidate gene-defects is presented.

  4. Zebrafish: modeling for herpes simplex virus infections.

    PubMed

    Antoine, Thessicar Evadney; Jones, Kevin S; Dale, Rodney M; Shukla, Deepak; Tiwari, Vaibhav

    2014-02-01

    For many years, zebrafish have been the prototypical model for studies in developmental biology. In recent years, zebrafish has emerged as a powerful model system to study infectious diseases, including viral infections. Experiments conducted with herpes simplex virus type-1 in adult zebrafish or in embryo models are encouraging as they establish proof of concept with viral-host tropism and possible screening of antiviral compounds. In addition, the presence of human homologs of viral entry receptors in zebrafish such as 3-O sulfated heparan sulfate, nectins, and tumor necrosis factor receptor superfamily member 14-like receptor bring strong rationale for virologists to test their in vivo significance in viral entry in a zebrafish model and compare the structure-function basis of virus zebrafish receptor interaction for viral entry. On the other end, a zebrafish model is already being used for studying inflammation and angiogenesis, with or without genetic manipulations, and therefore can be exploited to study viral infection-associated pathologies. The major advantage with zebrafish is low cost, easy breeding and maintenance, rapid lifecycle, and a transparent nature, which allows visualizing dissemination of fluorescently labeled virus infection in real time either at a localized region or the whole body. Further, the availability of multiple transgenic lines that express fluorescently tagged immune cells for in vivo imaging of virus infected animals is extremely attractive. In addition, a fully developed immune system and potential for receptor-specific knockouts further advocate the use of zebrafish as a new tool to study viral infections. In this review, we focus on expanding the potential of zebrafish model system in understanding human infectious diseases and future benefits.

  5. Zebrafish: Modeling for Herpes Simplex Virus Infections

    PubMed Central

    Antoine, Thessicar Evadney; Jones, Kevin S.; Dale, Rodney M.; Shukla, Deepak

    2014-01-01

    Abstract For many years, zebrafish have been the prototypical model for studies in developmental biology. In recent years, zebrafish has emerged as a powerful model system to study infectious diseases, including viral infections. Experiments conducted with herpes simplex virus type-1 in adult zebrafish or in embryo models are encouraging as they establish proof of concept with viral-host tropism and possible screening of antiviral compounds. In addition, the presence of human homologs of viral entry receptors in zebrafish such as 3-O sulfated heparan sulfate, nectins, and tumor necrosis factor receptor superfamily member 14-like receptor bring strong rationale for virologists to test their in vivo significance in viral entry in a zebrafish model and compare the structure–function basis of virus zebrafish receptor interaction for viral entry. On the other end, a zebrafish model is already being used for studying inflammation and angiogenesis, with or without genetic manipulations, and therefore can be exploited to study viral infection-associated pathologies. The major advantage with zebrafish is low cost, easy breeding and maintenance, rapid lifecycle, and a transparent nature, which allows visualizing dissemination of fluorescently labeled virus infection in real time either at a localized region or the whole body. Further, the availability of multiple transgenic lines that express fluorescently tagged immune cells for in vivo imaging of virus infected animals is extremely attractive. In addition, a fully developed immune system and potential for receptor-specific knockouts further advocate the use of zebrafish as a new tool to study viral infections. In this review, we focus on expanding the potential of zebrafish model system in understanding human infectious diseases and future benefits. PMID:24266790

  6. Morphogenesis and regionalization of the medaka embryonic brain.

    PubMed

    Kage, Takahiro; Takeda, Hiroyuki; Yasuda, Takako; Maruyama, Kouichi; Yamamoto, Naoyuki; Yoshimoto, Masami; Araki, Kazuo; Inohaya, Keiji; Okamoto, Hiroyuki; Yasumasu, Shigeki; Watanabe, Kaori; Ito, Hironobu; Ishikawa, Yuji

    2004-08-23

    We examined the morphogenesis and regionalization of the embryonic brain of an acanthopterygian teleost, medaka (Oryzias latipes), by in situ hybridization using 14 gene probes. We compared our results with previous studies in other vertebrates, particularly zebrafish, an ostariophysan teleost. During the early development of the medaka neural rod, three initial brain vesicles arose: the anterior brain vesicle, which later developed into the telencephalon and rostral diencephalon; the intermediate brain vesicle, which later developed into the caudal diencephalon, mesencephalon, and metencephalon; and the posterior brain vesicle, which later developed into the myelencephalon. In the late neural rod, the rostral brain bent ventrally and the axis of the brain had a marked curvature at the diencephalon. In the final stage of the neural rod, ventricles began to develop, transforming the neural rod into the neural tube. In situ hybridization revealed that the brain can be divided into three longitudinal zones (dorsal, intermediate, and ventral) and many transverse subdivisions, on the basis of molecular expression patterns. The telencephalon was subdivided into two transverse domains. Our results support the basic concept of neuromeric models, including the prosomeric model, which suggests the existence of a conserved organization of all vertebrate neural tubes. Our results also show that brain development in medaka differs from that reported in other vertebrates, including zebrafish, in gene-expression patterns in the telencephalon, in brain vesicle formation, and in developmental speed. Developmental and genetic programs for brain development may be somewhat different even among teleosts.

  7. Streptococcus-Zebrafish Model of Bacterial Pathogenesis

    PubMed Central

    Neely, Melody N.; Pfeifer, John D.; Caparon, Michael

    2002-01-01

    Due to its small size, rapid generation time, powerful genetic systems, and genomic resources, the zebrafish has emerged as an important model of vertebrate development and human disease. Its well-developed adaptive and innate cellular immune systems make the zebrafish an ideal model for the study of infectious diseases. With a natural and important pathogen of fish, Streptococcus iniae, we have established a streptococcus- zebrafish model of bacterial pathogenesis. Following injection into the dorsal muscle, zebrafish developed a lethal infection, with a 50% lethal dose of 103 CFU, and died within 2 to 3 days. The pathogenesis of infection resembled that of S. iniae in farmed fish populations and that of several important human streptococcal diseases and was characterized by an initial focal necrotic lesion that rapidly progressed to invasion of the pathogen into all major organ systems, including the brain. Zebrafish were also susceptible to infection by the human pathogen Streptococcus pyogenes. However, disease was characterized by a marked absence of inflammation, large numbers of extracellular streptococci in the dorsal muscle, and extensive myonecrosis that occurred far in advance of any systemic invasion. The genetic systems available for streptococci, including a novel method of mutagenesis which targets genes whose products are exported, were used to identify several mutants attenuated for virulence in zebrafish. This combination of a genetically amenable pathogen with a well-defined vertebrate host makes the streptococcus-zebrafish model of bacterial pathogenesis a powerful model for analysis of infectious disease. PMID:12065534

  8. Neuroblastoma and Its Zebrafish Model.

    PubMed

    Zhu, Shizhen; Thomas Look, A

    2016-01-01

    Neuroblastoma, an important developmental tumor arising in the peripheral sympathetic nervous system (PSNS), accounts for approximately 10 % of all cancer-related deaths in children. Recent genomic analyses have identified a spectrum of genetic alterations in this tumor. Amplification of the MYCN oncogene is found in 20 % of cases and is often accompanied by mutational activation of the ALK (anaplastic lymphoma kinase) gene, suggesting their cooperation in tumor initiation and spread. Understanding how complex genetic changes function together in oncogenesis has been a continuing and daunting task in cancer research. This challenge was addressed in neuroblastoma by generating a transgenic zebrafish model that overexpresses human MYCN and activated ALK in the PSNS, leading to tumors that closely resemble human neuroblastoma and new opportunities to probe the mechanisms that underlie the pathogenesis of this tumor. For example, coexpression of activated ALK with MYCN in this model triples the penetrance of neuroblastoma and markedly accelerates tumor onset, demonstrating the interaction of these modified genes in tumor development. Further, MYCN overexpression induces adrenal sympathetic neuroblast hyperplasia, blocks chromaffin cell differentiation, and ultimately triggers a developmentally-timed apoptotic response in the hyperplastic sympathoadrenal cells. In the context of MYCN overexpression, activated ALK provides prosurvival signals that block this apoptotic response, allowing continued expansion and oncogenic transformation of hyperplastic neuroblasts, thus promoting progression to neuroblastoma. This application of the zebrafish model illustrates its value in rational assessment of the multigenic changes that define neuroblastoma pathogenesis and points the way to future studies to identify novel targets for therapeutic intervention.

  9. Zebrafish models of cerebrovascular disease.

    PubMed

    Walcott, Brian P; Peterson, Randall T

    2014-04-01

    Perturbations in cerebral blood flow and abnormalities in blood vessel structure are the hallmarks of cerebrovascular disease. While there are many genetic and environmental factors that affect these entities through a heterogeneous group of disease processes, the ultimate final pathologic insult in humans is defined as a stroke, or damage to brain parenchyma. In the case of ischemic stroke, blood fails to reach its target destination whereas in hemorrhagic stroke, extravasation of blood occurs outside of the blood vessel lumen, resulting in direct damage to brain parenchyma. As these acute events can be neurologically devastating, if not fatal, development of novel therapeutics are urgently needed. The zebrafish (Danio rerio) is an attractive model for the study of cerebrovascular disease because of its morphological and physiological similarity to human cerebral vasculature, its ability to be genetically manipulated, and its fecundity allowing for large-scale, phenotype-based screens.

  10. Zebrafish Models for Human Acute Organophosphorus Poisoning

    PubMed Central

    Faria, Melissa; Garcia-Reyero, Natàlia; Padrós, Francesc; Babin, Patrick J.; Sebastián, David; Cachot, Jérôme; Prats, Eva; Arick II, Mark; Rial, Eduardo; Knoll-Gellida, Anja; Mathieu, Guilaine; Le Bihanic, Florane; Escalon, B. Lynn; Zorzano, Antonio; Soares, Amadeu M.V.M; Raldúa, Demetrio

    2015-01-01

    Terrorist use of organophosphorus-based nerve agents and toxic industrial chemicals against civilian populations constitutes a real threat, as demonstrated by the terrorist attacks in Japan in the 1990 s or, even more recently, in the Syrian civil war. Thus, development of more effective countermeasures against acute organophosphorus poisoning is urgently needed. Here, we have generated and validated zebrafish models for mild, moderate and severe acute organophosphorus poisoning by exposing zebrafish larvae to different concentrations of the prototypic organophosphorus compound chlorpyrifos-oxon. Our results show that zebrafish models mimic most of the pathophysiological mechanisms behind this toxidrome in humans, including acetylcholinesterase inhibition, N-methyl-D-aspartate receptor activation, and calcium dysregulation as well as inflammatory and immune responses. The suitability of the zebrafish larvae to in vivo high-throughput screenings of small molecule libraries makes these models a valuable tool for identifying new drugs for multifunctional drug therapy against acute organophosphorus poisoning. PMID:26489395

  11. Zebrafish Models for Human Acute Organophosphorus Poisoning.

    PubMed

    Faria, Melissa; Garcia-Reyero, Natàlia; Padrós, Francesc; Babin, Patrick J; Sebastián, David; Cachot, Jérôme; Prats, Eva; Arick Ii, Mark; Rial, Eduardo; Knoll-Gellida, Anja; Mathieu, Guilaine; Le Bihanic, Florane; Escalon, B Lynn; Zorzano, Antonio; Soares, Amadeu M V M; Raldúa, Demetrio

    2015-10-22

    Terrorist use of organophosphorus-based nerve agents and toxic industrial chemicals against civilian populations constitutes a real threat, as demonstrated by the terrorist attacks in Japan in the 1990 s or, even more recently, in the Syrian civil war. Thus, development of more effective countermeasures against acute organophosphorus poisoning is urgently needed. Here, we have generated and validated zebrafish models for mild, moderate and severe acute organophosphorus poisoning by exposing zebrafish larvae to different concentrations of the prototypic organophosphorus compound chlorpyrifos-oxon. Our results show that zebrafish models mimic most of the pathophysiological mechanisms behind this toxidrome in humans, including acetylcholinesterase inhibition, N-methyl-D-aspartate receptor activation, and calcium dysregulation as well as inflammatory and immune responses. The suitability of the zebrafish larvae to in vivo high-throughput screenings of small molecule libraries makes these models a valuable tool for identifying new drugs for multifunctional drug therapy against acute organophosphorus poisoning.

  12. Zebrafish as a model for systems biology.

    PubMed

    Mushtaq, Mian Yahya; Verpoorte, Robert; Kim, Hye Kyong

    2013-01-01

    Zebrafish offer a unique vertebrate model for research areas such as drug development, disease modeling and other biological exploration. There is significant conservation of genetics and other cellular networks among zebrafish and other vertebrate models, including humans. Here we discuss the recent work and efforts made in different fields of biology to explore the potential of zebrafish. Along with this, we also reviewed the concept of systems biology. A biological system is made up of a large number of components that interact in a huge variety of combinations. To understand completely the behavior of a system, it is important to know its components and interactions, and this can be achieved through a systems biology approach. At the end of the paper we present a concept of integrating zebrafish into the systems biology approach.

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

    PubMed

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

    2014-05-01

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

  14. Modeling Syndromic Congenital Heart Defects in Zebrafish.

    PubMed

    Grant, Meagan G; Patterson, Victoria L; Grimes, Daniel T; Burdine, Rebecca D

    2017-01-01

    Cardiac development is a dynamic process regulated by spatial and temporal cues that are integrated to effect molecular, cellular, and tissue-level events that form the adult heart. Disruption of these highly orchestrated events can be devastating for cardiac form and function. Aberrations in heart development result in congenital heart defects (CHDs), which affect 1 in 100 infants in the United States each year. Zebrafish have proven informative as a model organism to understand both heart development and the mechanisms associated with CHDs due to the similarities in heart morphogenesis among vertebrates, as well as their genetic tractability and amenability to live imaging. In this review, we discuss the mechanisms of zebrafish heart development and the utility of zebrafish for understanding syndromic CHDs, those cardiac abnormalities that occur in the context of multisystem disorders. We conclude with avenues of zebrafish research that will potentially inform future therapeutic approaches for the treatment of CHDs.

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

    PubMed Central

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

    2013-01-01

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

  16. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment.

    PubMed

    Hobbie, Kristen R; Deangelo, Anthony B; King, Leon C; Winn, Richard N; Law, J McHugh

    2009-03-01

    Recent changes in the risk assessment landscape underscore the need to be able to compare the results of toxicity and dose-response testing between a growing list of animal models and, quite possibly, an array of in vitro screening assays. How do we compare test results for a given compound between vastly different species? For example, what dose level in the ambient water of a small fish model would be equivalent to 10 ppm of a given compound in the rat's drinking water? Where do we begin? To initially address these questions, and in order to compare dose-response tests in a standard rodent model with a fish model, we used the concept of molecular dose. Assays that quantify types of DNA damage that are directly relevant to carcinogenesis integrate the factors such as chemical exposure, uptake, distribution, metabolism, etc. that tend to vary so widely between different phyletic levels. We performed parallel exposures in F344 rats and Japanese medaka (Oryzias latipes) to the alkylating hepatocarcinogen, dimethylnitrosamine (DMN). In both models, we measured the DNA adducts 8-hydroxyguanine, N(7)-methylguanine and O(6)-methylguanine in the liver; mutation frequency using lambda cII transgenic medaka and lambda cII transgenic (Big Blue(R)) rats; and early morphological changes in the livers of both models using histopathology and immunohistochemistry. Pulse dose levels in fish were 0, 10, 25, 50, or 100 ppm DMN in the ambient water for 14 days. Since rats are reported to be especially sensitive to DMN, they received 0, 0.1, 1, 5, 10, or 25 ppm DMN in the drinking water for the same time period. While liver DNA adduct concentrations were similar in magnitude, mutant frequencies in the DMN-exposed medaka were up to 20 times higher than in the Big Blue rats. Future work with other compounds will generate a more complete picture of comparative dose response between different phyletic levels and will help guide risk assessors using "alternative" models.

  17. Homology-modeled ligand-binding domains of medaka estrogen receptors and androgen receptors: A model system for the study of reproduction

    SciTech Connect

    Cui Jianzhou Shen Xueyan; Yan Zuowei; Zhao Haobin; Nagahama, Yoshitaka

    2009-02-27

    Estrogen and androgen and their receptors play critical roles in physiological processes such as sexual differentiation and development. Using the available structural models for the human estrogen receptors alpha and beta and androgen receptor as templates, we designed in silico agonist and antagonist models of medaka estrogen receptor (meER) alpha, beta-1, and beta-2, and androgen receptor (meAR) alpha and beta. Using these models, we studied (1) the structural relationship between the ligand-binding domains (LBDs) of ERs and ARs of human and medaka, and (2) whether medaka ER and AR can be potential models for studying the ligand-binding activities of various agonists and antagonists of these receptors by docking analysis. A high level of conservation was observed between the sequences of the ligand-binding domains of meER{alpha} and huER{alpha}, meER{beta}1 and huER{beta}, meER{beta}2, and huER{beta} with 62.8%, 66.4%, and 65.1% identity, respectively. The sequence conservation between meAR{alpha} and huAR, meAR{beta}, and huAR was found with 70.1% and 61.0% of identity, respectively. Thirty-three selected endocrine disrupting chemicals (EDCs), including both agonists and antagonists, were docked into the LBD of ER and AR, and the corresponding docking score for medaka models and human templates were calculated. In order to confirm the conservation of the overall geometry and the binding pocket, the backbone root mean square deviation (RMSD) for C{alpha} atoms was derived from the structure superposition of all 10 medaka homology models to the six human templates. Our results suggested conformational conservation between the ERs and ARs of medaka and human, Thus, medaka could be highly useful as a model system for studies involving estrogen and androgen interaction with their receptors.

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

    PubMed

    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.

  19. Zebrafish heart as a model for human cardiac electrophysiology.

    PubMed

    Vornanen, Matti; Hassinen, Minna

    2016-01-01

    The zebrafish (Danio rerio) has become a popular model for human cardiac diseases and pharmacology including cardiac arrhythmias and its electrophysiological basis. Notably, the phenotype of zebrafish cardiac action potential is similar to the human cardiac action potential in that both have a long plateau phase. Also the major inward and outward current systems are qualitatively similar in zebrafish and human hearts. However, there are also significant differences in ionic current composition between human and zebrafish hearts, and the molecular basis and pharmacological properties of human and zebrafish cardiac ionic currents differ in several ways. Cardiac ionic currents may be produced by non-orthologous genes in zebrafish and humans, and paralogous gene products of some ion channels are expressed in the zebrafish heart. More research on molecular basis of cardiac ion channels, and regulation and drug sensitivity of the cardiac ionic currents are needed to enable rational use of the zebrafish heart as an electrophysiological model for the human heart.

  20. Transgenic medaka fish as models to analyze bone homeostasis under micro-gravity conditions in vivo

    NASA Astrophysics Data System (ADS)

    Winkler, C.; Wagner, T.; Renn, J.; Goerlich, R.; Schartl, M.

    Long-term space flight and microgravity results in bone loss that can be explained by reduced activity of bone-forming osteoblast cells and/or an increase in activity of bone resorbing osteoclast cells. Osteoprotegerin (OPG), a secreted protein of 401 amino acids, has been shown to regulate the balance between osteoblast and osteoclast formation and thereby warrants constant bone mass under normal gravitational conditions. Consistent with this, earlier reports using transgenic mice have shown that increased activation of OPG leads to exc essive bone formation (osteopetrosis), while inactivation of OPG leads to bone loss (osteoporosis). Importantly, it has recently been reported that expression of murine OPG is regulated by vector averaged gravity (Kanematsu et al., 2002, Bone 30, p553). The small bony fish medaka (Oryzias latipes ) has attracted increasing attention as genetic model system to study developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two related genes, opr-1 and opr -2, from medaka. Our phylogenetic analysis revealed that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian OPG gene. Both opr genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast cells. We have characterized their promoter regions and identified consensus binding sites for transcription factors of the bone-morphogenetic-protein (BMP) p thway and for core-binding-factor-1Aa (cbfa1). Cbfa1 has been shown to be the key regulator of OPG expression during several steps of osteoblast differentiation in mammals. This opens the possibility that the mechanisms controlling bone formation in teleost fish and higher vertebrates are regulated by related mechanisms. We are currently generating transgenic medakafish expressing a GFP reporter gene under control of the

  1. Zebrafish as an emerging model for studying complex brain disorders

    PubMed Central

    Kalueff, Allan V.; Stewart, Adam Michael; Gerlai, Robert

    2014-01-01

    The zebrafish (Danio rerio) is rapidly becoming a popular model organism in pharmacogenetics and neuropharmacology. Both larval and adult zebrafish are currently used to increase our understanding of brain function, dysfunction, and their genetic and pharmacological modulation. Here we review the developing utility of zebrafish in the analysis of complex brain disorders (including, for example, depression, autism, psychoses, drug abuse and cognitive disorders), also covering zebrafish applications towards the goal of modeling major human neuropsychiatric and drug-induced syndromes. We argue that zebrafish models of complex brain disorders and drug-induced conditions have become a rapidly emerging critical field in translational neuropharmacology research. PMID:24412421

  2. Formation and cultivation of medaka primordial germ cells.

    PubMed

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  3. Zebrafish Embryo Model of Bartonella henselae Infection

    PubMed Central

    Lima, Amorce; Cha, Byeong J.; Amin, Jahanshah; Smith, Lisa K.

    2014-01-01

    Abstract Bartonella henselae (Bh) is an emerging zoonotic pathogen that has been associated with a variety of human diseases, including bacillary angiomatosis that is characterized by vasoproliferative tumor-like lesions on the skin of some immunosuppressed individuals. The study of Bh pathogenesis has been limited to in vitro cell culture systems due to the lack of an animal model. Therefore, we wanted to investigate whether the zebrafish embryo could be used to model human infection with Bh. Our data showed that Tg(fli1:egfp)y1 zebrafish embryos supported a sustained Bh infection for 7 days with >10-fold bacterial replication when inoculated in the yolk sac. We showed that Bh recruited phagocytes to the site of infection in the Tg(mpx:GFP)uwm1 embryos. Infected embryos showed evidence of a Bh-induced angiogenic phenotype and an increase in the expression of genes encoding pro-inflammatory factors and pro-angiogenic markers. However, infection of zebrafish embryos with a deletion mutant in the major adhesin (BadA) resulted in little or no bacterial replication and a diminished host response, providing the first evidence that BadA is critical for in vivo infection. Thus, the zebrafish embryo provides the first practical model of Bh infection that will facilitate efforts to identify virulence factors and define molecular mechanisms of Bh pathogenesis. PMID:25026365

  4. Zebrafish embryo model of Bartonella henselae infection.

    PubMed

    Lima, Amorce; Cha, Byeong J; Amin, Jahanshah; Smith, Lisa K; Anderson, Burt

    2014-10-01

    Bartonella henselae (Bh) is an emerging zoonotic pathogen that has been associated with a variety of human diseases, including bacillary angiomatosis that is characterized by vasoproliferative tumor-like lesions on the skin of some immunosuppressed individuals. The study of Bh pathogenesis has been limited to in vitro cell culture systems due to the lack of an animal model. Therefore, we wanted to investigate whether the zebrafish embryo could be used to model human infection with Bh. Our data showed that Tg(fli1:egfp)(y1) zebrafish embryos supported a sustained Bh infection for 7 days with >10-fold bacterial replication when inoculated in the yolk sac. We showed that Bh recruited phagocytes to the site of infection in the Tg(mpx:GFP)uwm1 embryos. Infected embryos showed evidence of a Bh-induced angiogenic phenotype and an increase in the expression of genes encoding pro-inflammatory factors and pro-angiogenic markers. However, infection of zebrafish embryos with a deletion mutant in the major adhesin (BadA) resulted in little or no bacterial replication and a diminished host response, providing the first evidence that BadA is critical for in vivo infection. Thus, the zebrafish embryo provides the first practical model of Bh infection that will facilitate efforts to identify virulence factors and define molecular mechanisms of Bh pathogenesis.

  5. Developing 'integrative' zebrafish models of behavioral and metabolic disorders.

    PubMed

    Nguyen, Michael; Yang, Ester; Neelkantan, Nikhil; Mikhaylova, Alina; Arnold, Raymond; Poudel, Manoj K; Stewart, Adam Michael; Kalueff, Allan V

    2013-11-01

    Recently, the pathophysiological overlap between metabolic and mental disorders has received increased recognition. Zebrafish (Danio rerio) are rapidly becoming a popular model organism for translational biomedical research due to their genetic tractability, low cost, quick reproductive cycle, and ease of behavioral, pharmacological or genetic manipulation. High homology to mammalian physiology and the availability of well-developed assays also make the zebrafish an attractive organism for studying human disorders. Zebrafish neurobehavioral and endocrine phenotypes show promise for the use of zebrafish in studies of stress, obesity and related behavioral and metabolic disorders. Here, we discuss the parallels between zebrafish and other model species in stress and obesity physiology, as well as outline the available zebrafish models of weight gain, metabolic deficits, feeding, stress, anxiety and related behavioral disorders. Overall, zebrafish demonstrate a strong potential for modeling human behavioral and metabolic disorders, and their comorbidity.

  6. The teleost fish medaka (Oryzias latipes) as genetic model to study gravity dependent bone homeostasis in vivo.

    PubMed

    Wagner, T U; Renn, J; Riemensperger, T; Volff, J-N; Köster, R W; Goerlich, R; Schartl, M; Winkler, C

    2003-01-01

    Long-term space flight and microgravity result in bone loss that can be explained by reduced activity of bone-forming cells (osteoblasts) and/or an increase in activity of bone resorbing cells (osteoclasts). Osteoprotegerin (OPG) has been shown to regulate the balance between osteoblast and osteoclast cell numbers and is involved in maintaining constant bone mass under normal gravitational conditions. The small bony fish medaka (Oryzias latipes) has attracted increasing attention as a genetic model system to study normal embryonic developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two opg genes, opgl and opg2, from medaka. Our phylogenetic analysis reveals that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian opg gene. Both opg genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast-like cells. Furthermore, we have characterized the opg2 promoter region and identified consensus binding sites for the transcription factor core-binding-factor-1A (CBFA1). In mammals, CBFA1 has been shown to be a regulator of opg expression and to be essential for several steps during osteoblast differentiation. Here we show that sequence and expression domains of opg, cbfal and a member of the dlx gene family are highly conserved between medaka and higher vertebrates. This suggests that not only single genes but entire genetic networks for bone formation are conserved between teleosts and mammals. These findings will open medaka fish as a genetic model to monitor bone formation under different gravity conditions in a living whole animal allowing the identification of novel factors involved in bone homeostasis.

  7. The teleost fish medaka ( Oryzias latipes) as genetic model to study gravity dependent bone homeostasis in vivo

    NASA Astrophysics Data System (ADS)

    Wagner, T. U.; Renn, J.; Riemensperger, T.; Volff, J.-N.; Köster, R. W.; Goerlich, R.; Schartl, M.; Winkler, C.

    2003-10-01

    Long-term space flight and microgravity result in bone loss that can be explained by reduced activity of bone-forming cells (osteoblasts) and/or an increase in activity of bone resorbing cells (osteoclasts). Osteoprotegerin (OPG) has been shown to regulate the balance between osteoblast and osteoclast cell numbers and is involved in maintaining constant bone mass under normal gravitational conditions. The small bony fish medaka ( Oryzias latipes) has attracted increasing attention as a genetic model system to study normal embryonic developmental and pathological processes. To analyze the molecular mechanisms of bone formation in this small vertebrate, we have isolated two opg genes, opgl and opg2, from medaka. Our phylogenetic analysis reveals that both genes originated from a common ancestor by fish-specific gene duplication and represent the orthologs of the mammalian opg gene. Both opg genes are differentially expressed during embryonic and larval development, in adult tissues and in cultured primary osteoblast-like cells. Furthermore, we have characterized the opg2 promoter region and identified consensus binding sites for the transcription factor core-binding-factor-1A (CBFA1). In mammals, CBFA1 has been shown to be a regulator of opg expression and to be essential for several steps during osteoblast differentiation. Here we show that sequence and expression domains of opg, cbfal and a member of the dlx gene family are highly conserved between medaka and higher vertebrates. This suggests that not only single genes but entire genetic networks for bone formation are conserved between teleosts and mammals. These findings will open medaka fish as a genetic model to monitor bone formation under different gravity conditions in a living whole animal allowing the identification of novel factors involved in bone homeostasis.

  8. Report of the Second European Zebrafish Principal Investigator Meeting in Karlsruhe, Germany, March 21-24, 2012.

    PubMed

    Cavodeassi, Florencia; Del Bene, Filippo; Fürthauer, Maximilian; Grabher, Clemens; Herzog, Wiebke; Lehtonen, Sanna; Linker, Claudia; Mercader, Nadia; Mikut, Ralf; Norton, William; Strähle, Uwe; Tiso, Natascia; Foulkes, Nicholas S

    2013-03-01

    The second European Zebrafish Principal Investigator (PI) Meeting was held in March, 2012, in Karlsruhe, Germany. It brought together PIs from all over Europe who work with fish models such as zebrafish and medaka to discuss their latest results, as well as to resolve strategic issues faced by this research community. Scientific discussion ranged from the development of new technologies for working with fish models to progress in various fields of research such as injury and repair, disease models, and cell polarity and dynamics. This meeting also marked the establishment of the European Zebrafish Resource Centre (EZRC) at Karlsruhe that in the future will serve as an important focus and community resource for zebrafish- and medaka-based research.

  9. Neurocytotoxic effects of iron-ions on the developing brain measured in vivo using medaka (Oryzias latipes), a vertebrate model

    PubMed Central

    Yasuda, Takako; Oda, Shoji; Yasuda, Hiroshi; Hibi, Yusuke; Anzai, Kazunori; Mitani, Hiroshi

    2011-01-01

    Purpose: Exposure to heavy-ion radiation is considered a critical health risk on long-term space missions. The developing central nervous system (CNS) is a highly radiosensitive tissue; however, the biological effects of heavy-ion radiation, which are greater than those of low-linear energy transfer (LET) radiation, are not well studied, especially in vivo in intact organisms. Here, we examined the effects of iron-ions on the developing CNS using vertebrate organism, fish embryos of medaka (Oryzias latipes). Materials and methods: Medaka embryos at developmental stage 28 were irradiated with iron-ions at various doses of 0-1.5 Gy. At 24 h after irradiation, radiation-induced apoptosis was examined using an acridine orange (AO) assay and histo-logically. To estimate the relative biological effectiveness (RBE), we quantified only characteristic AO-stained rosette-shaped apoptosis in the developing optic tectum (OT). At the time of hatching, morphological abnormalities in the irradiated brain were examined histologically. Results: The dose-response curve utilizing an apoptotic index for the iron-ion irradiated embryos was much steeper than that for X-ray irradiated embryos, with RBE values of 3.7-4.2. Histological examinations of irradiated medaka brain at 24 h after irradiation showed AO-positive rosette-shaped clusters as aggregates of condensed nuclei, exhibiting a circular hole, mainly in the marginal area of the OT and in the retina. However, all of the irradiated embryos hatched normally without apparent histological abnormalities in their brains. Conclusion: Our present study indicates that the medaka embryo is a useful model for evaluating neurocytotoxic effects on the developing CNS induced by exposure to heavy iron-ions relevant to the aerospace radiation environment. PMID:21770703

  10. Zebrafish models of dyslipidemia: Relevance to atherosclerosis and angiogenesis

    PubMed Central

    Fang, Longhou; Liu, Chao; Miller, Yury I.

    2013-01-01

    Lipid and lipoprotein metabolism in zebrafish and in humans are remarkably similar. Zebrafish express all major nuclear receptors, lipid transporters, apolipoproteins and enzymes involved in lipoprotein metabolism. Unlike mice, zebrafish express cetp and the Cetp activity is detected in zebrafish plasma. Feeding zebrafish a high cholesterol diet, without any genetic intervention, results in significant hypercholesterolemia and robust lipoprotein oxidation, making zebrafish an attractive animal model to study mechanisms relevant to early development of human atherosclerosis. These studies are facilitated by the optical transparency of zebrafish larvae and the availability of transgenic zebrafish expressing fluorescent proteins in endothelial cells and macrophages. Thus, vascular processes can be monitored in live animals. In this review article we discuss recent advances in using dyslipidemic zebrafish in atherosclerosis-related studies. We also summarize recent work connecting lipid metabolism with regulation of angiogenesis, the work that considerably benefited from using the zebrafish model. These studies uncovered the role of aibp, abca1, abcg1, mtp, apoB and apoC2 in regulation of angiogenesis in zebrafish and paved the way for future studies in mammals, which may suggest new therapeutic approaches to modulation of excessive or diminished angiogenesis contributing to the pathogenesis of human disease. PMID:24095954

  11. Specification of primordial germ cells in medaka (Oryzias latipes)

    PubMed Central

    Herpin, Amaury; Rohr, Stefan; Riedel, Dietmar; Kluever, Nils; Raz, Erez; Schartl, Manfred

    2007-01-01

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

  12. Generation of medaka gene knockout models by target-selected mutagenesis

    PubMed Central

    Taniguchi, Yoshihito; Takeda, Shunichi; Furutani-Seiki, Makoto; Kamei, Yasuhiro; Todo, Takeshi; Sasado, Takao; Deguchi, Tomonori; Kondoh, Hisato; Mudde, Josine; Yamazoe, Mitsuyoshi; Hidaka, Masayuki; Mitani, Hiroshi; Toyoda, Atsushi; Sakaki, Yoshiyuki; Plasterk, Ronald HA; Cuppen, Edwin

    2006-01-01

    We have established a reverse genetics approach for the routine generation of medaka (Oryzias latipes) gene knockouts. A cryopreserved library of N-ethyl-N-nitrosourea (ENU) mutagenized fish was screened by high-throughput resequencing for induced point mutations. Nonsense and splice site mutations were retrieved for the Blm, Sirt1, Parkin and p53 genes and functional characterization of p53 mutants indicated a complete knockout of p53 function. The current cryopreserved resource is expected to contain knockouts for most medaka genes. PMID:17156454

  13. Zebrafish Models for Dyslipidemia and Atherosclerosis Research

    PubMed Central

    Schlegel, Amnon

    2016-01-01

    Atherosclerotic cardiovascular disease is the leading cause of death. Elevated circulating concentrations of lipids are a central pathogenetic driver of atherosclerosis. While numerous effective therapies for this condition have been developed, there is substantial unmet need for this pandemic illness. Here, I will review nutritional, physiological, genetic, and pathological discoveries in the emerging zebrafish model for studying dyslipidemia and atherosclerosis. The technical and physiological advantages and the pharmacological potential of this organism for discovery and validation of dyslipidemia and atherosclerosis targets are stressed through summary of recent findings. An emerging literature shows that zebrafish, through retention of a cetp ortholog gene and high sensitivity to ingestion of excess cholesterol, rapidly develops hypercholesterolemia, with a pattern of distribution of lipid species in lipoprotein particles similar to humans. Furthermore, recent studies leveraging the optical transparency of zebrafish larvae to monitor the fate of these ingested lipids have provided exciting insights to the development of dyslipidemia and atherosclerosis. Future directions for investigation are considered, with particular attention to the potential for in vivo cell biological study of atherosclerotic plaques. PMID:28018294

  14. A purified diet for medaka (Oryzias latipes): refining a fish model for toxicological research

    SciTech Connect

    DeKoven, D.L.; Nunez, J.M.; Lester, S.M.; Conklin, D.E.; Marty, G.D.; Parker, L.M.; Hinton, D.E. )

    1992-04-01

    The overall nutritional adequacy of a purified casein-based diet (PC-diet) for the medaka (Oryzias latipes) was evaluated and compared with three diets: commercially available flaked fish food (FL-diet), live newly hatched Artemia (A-diet), and a combination of FL-diet plus A-diet (F/A-diet). Survival, growth, reproductive success, general and liver histopathology, and selected hepatic enzyme activities were compared in medaka from first feeding through reproductive maturity. The PC-diet proved adequate in all of the above criteria. When compared with fish fed F/A-diet, an initial lag in early growth rates (i.e., 0 to 30 days) occurred with the fish fed PC-diet. The FL-diet alone was not nutritionally adequate for medaka, resulting in poor growth, reduced reproductive success, lower survival, and emaciation. A significant number of spinal deformities (5.4%) were noted in medaka fed the F/A diet. Ethoxycoumarin 0-deethylase and glutathione S-transferase activities were monitored and a trend toward increasing activity with age was noted. This suggests that PC- and F/A-diets provide adequate nutrition for development of the xenobiotic metabolizing enzymes necessary for detoxification and activation of endogenous and foreign compounds. The PC-diet supported good survival, growth, reproduction, and normal histology. This diet provides a standardized, nutritionally adequate, and consistent alternative to undefined conventional diets and is less likely to contain the range of xenobiotics possible in whole, live food.

  15. [Potential of the zebrafish model to study congenital muscular dystrophies].

    PubMed

    Ryckebüsch, Lucile

    2015-10-01

    In order to better understand the complexity of congenital muscular dystrophies (CMD) and develop new strategies to cure them, it is important to establish new disease models. Due to its numerous helpful attributes, the zebrafish has recently become a very powerful animal model for the study of CMD. For some CMD, this vertebrate model is phenotypically closer to human pathology than the murine model. Over the last few years, researchers have developed innovative techniques to screen rapidly and on a large scale for muscle defects in zebrafish. Furthermore, new genome editing techniques in zebrafish make possible the identification of new disease models. In this review, the major attributes of zebrafish for CMD studies are discussed and the principal models of CMD in zebrafish are highlighted.

  16. Hepatotoxicity of the drinking water disinfection by-product, dichloroacetic acid, in the medaka small fish model.

    PubMed

    McHugh Law, J; Lopez, L; DeAngelo, A B

    1998-01-16

    Recent studies have shown that dichloroacetic acid (DCA), a by-product of chlorination of public water supplies, is carcinogenic to both rats and mice. However, conflicting data have left the mechanism of DCA carcinogenicity, vital to assessment of human health risk, unclear. Elucidation of this mechanism in another animal model at a different phyletic level than rodents would advance the risk assessment process for government agencies concerned with regulation and provision of safe drinking water. The Japanese medaka (Oryzias latipes), a well characterized small fish model, is being used increasingly for carcinogenicity testing because of its low cost, ease of maintenance and carcinogen sensitivity. In this study, 6-week-old medaka were exposed to diethylnitrosamine (DEN, a known initiator), followed by continuous exposure to 0.5 or 2.0 g/l DCA in the ambient water, over a 4 week period. At both exposure concentrations, changes in the liver included marked hepatocellular cytoplasmic vacuolation, cytomegaly, karyomegaly, nuclear atypia and multifocal areas of hepatocellular necrosis and loss as early as week two of DCA exposure. The majority of the hepatocellular cytoplasmic vacuoles were shown by periodic acid Schiff (PAS) staining to contain large amounts of glycogen. These elevated glycogen levels may reflect a disruption in the enzyme pathways for glycolysis. The total cellular changes seen in this short-term exposure regimen are compatible with preneoplastic changes seen in rats and mice exposed to DCA. The results of this study strengthen the role of the Japanese medaka as a suitable species in carcinogenicity testing as well as its implementation in the risk assessment process for DCA across several phyletic levels.

  17. Dual control by a single gene of secondary sexual characters and mating preferences in medaka

    PubMed Central

    Fukamachi, Shoji; Kinoshita, Masato; Aizawa, Kouichi; Oda, Shoji; Meyer, Axel; Mitani, Hiroshi

    2009-01-01

    Background Animals utilize a wide variety of tactics to attract reproductive partners. Behavioral experiments often indicate an important role for visual cues in fish, but their molecular basis remains almost entirely unknown. Studies on model species (such as zebrafish and medaka) allow investigations into this fundamental question in behavioral and evolutionary biology. Results Through mate-choice experiences using several laboratory strains of various body colors, we successfully identified one medaka mutant (color interfere; ci) that is distinctly unattractive to reproductive partners. This unattractiveness seems to be due to reduced orange pigment cells (xanthophores) in the skin. The ci strain carries a mutation on the somatolactin alpha (SLa) gene, therefore we expected over-expression of SLa to make medaka hyper-attractive. Indeed, extremely strong mating preferences were detected in a choice between the ci and SLa-transgenic (Actb-SLa:GFP) medaka. Intriguingly, however, the strains showed opposite biases; that is, the mutant and transgenic medaka liked to mate with partners from their own strain, similar to becoming sexually isolated. Conclusion This study spotlighted SLa as a novel mate-choice gene in fish. In addition, these results are the first demonstration of a single gene that can pleiotropically and harmoniously change both secondary sexual characters and mating preferences. Although theoretical models have long suggested joint evolution of linked genes on a chromosome, a mutation on a gene-regulatory region (that is, switching on/off of a single gene) might be sufficient to trigger two 'runaway' processes in different directions to promote (sympatric) speciation. PMID:19788724

  18. Modeling anxiety using adult zebrafish: A conceptual review

    PubMed Central

    Stewart, Adam; Gaikwad, Siddharth; Kyzar, Evan; Green, Jeremy; Roth, Andrew; Kalueff, Allan V.

    2011-01-01

    Zebrafish (Danio rerio) are rapidly emerging as a useful animal model in neurobehavioral research. Mounting evidence shows the suitability of zebrafish to model various aspects of anxiety-related states. Here, we evaluate established and novel approaches to uncover the molecular substrates, genetic pathways and neural circuits of anxiety using adult zebrafish. Experimental approaches to modeling anxiety in zebrafish include novelty-based paradigms, pharmacological and genetic manipulations, as well as innovative video-tracking, 3D-reconstructions and bioinformatics-based searchable databases and omics-based tools. Complementing traditional rodent models of anxiety, we provide a conceptual framework for the wider application of zebrafish and other aquatic models in anxiety research. PMID:21843537

  19. Host-Pathogen Interactions Made Transparent with the Zebrafish Model

    PubMed Central

    Meijer, Annemarie H; Spaink, Herman P

    2011-01-01

    The zebrafish holds much promise as a high-throughput drug screening model for immune-related diseases, including inflammatory and infectious diseases and cancer. This is due to the excellent possibilities for in vivo imaging in combination with advanced tools for genomic and large scale mutant analysis. The context of the embryo’s developing immune system makes it possible to study the contribution of different immune cell types to disease progression. Furthermore, due to the temporal separation of innate immunity from adaptive responses, zebrafish embryos and larvae are particularly useful for dissecting the innate host factors involved in pathology. Recent studies have underscored the remarkable similarity of the zebrafish and human immune systems, which is important for biomedical applications. This review is focused on the use of zebrafish as a model for infectious diseases, with emphasis on bacterial pathogens. Following a brief overview of the zebrafish immune system and the tools and methods used to study host-pathogen interactions in zebrafish, we discuss the current knowledge on receptors and downstream signaling components that are involved in the zebrafish embryo’s innate immune response. We summarize recent insights gained from the use of bacterial infection models, particularly the Mycobacterium marinum model, that illustrate the potential of the zebrafish model for high-throughput antimicrobial drug screening. PMID:21366518

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

    USGS Publications Warehouse

    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.

  1. Zebrafish models for translational neuroscience research: from tank to bedside

    PubMed Central

    Stewart, Adam Michael; Braubach, Oliver; Spitsbergen, Jan; Gerlai, Robert; Kalueff, Allan V.

    2014-01-01

    The zebrafish (Danio rerio) is emerging as a new important species for studying mechanisms of brain function and dysfunction. Focusing on selected central nervous system (CNS) disorders (brain cancer, epilepsy, and anxiety) and using them as examples, we discuss the value of zebrafish models in translational neuroscience. We further evaluate the contribution of zebrafish to neuroimaging, circuit level, and drug discovery research. Outlining the role of zebrafish in modeling a wide range of human brain disorders, we also summarize recent applications and existing challenges in this field. Finally, we emphasize the potential of zebrafish models in behavioral phenomics and high-throughput genetic/small molecule screening, which is critical for CNS drug discovery and identifying novel candidate genes. PMID:24726051

  2. montalcino, a Zebrafish Model for Variegate Porphyria

    PubMed Central

    Dooley, Kimberly A.; Fraenkel, Paula G.; Langer, Nathaniel B.; Schmid, Bettina; Davidson, Alan J.; Weber, Gerhard; Chiang, Ken; Foott, Helen; Dwyer, Caitlin; Wingert, Rebecca A.; Zhou, Yi; Paw, Barry H.; Zon, Leonard I.

    2008-01-01

    Objective Inherited or acquired mutations in the heme biosynthetic pathway lead to a debilitating class of diseases collectively known as porphyrias, with symptoms that can include anemia, cutaneous photosensitivity, and neurovisceral dysfunction. In a genetic screen for hematopoietic mutants, we isolated a zebrafish mutant, montalcino (mno), which displays hypochromic anemia and porphyria. The objective of this study was to identify the defective gene and characterize the phenotype of the zebrafish mutant. Methods Genetic linkage analysis was utilized to identify the region harboring the mno mutation. Candidate gene analysis together with RT-PCR was utilized to identify the genetic mutation, which was confirmed via allele specific oligo hybridizations. Whole mount in situ hybridizations and 0-dianisidine staining were used to characterize the phenotype of the mno mutant. mRNA and morpholino microinjections were performed to phenocopy and/or rescue the mutant phenotype. Results Homozygous mno mutant embryos have a defect in the protoporphyrinogen oxidase (ppox) gene, which encodes the enzyme that catalyzes the oxidation of protoporphyrinogen. Homozygous mutant embryos are deficient in hemoglobin, and by 36 hpf are visibly anemic and porphyric. The hypochromic anemia of mno embryos was partially rescued by human ppox, providing evidence for the conservation of function between human and zebrafish ppox. Conclusion In humans, mutations in ppox result in variegate porphyria. At present, effective treatment for acute attacks requires the administration intravenous hemin and/or glucose. Thus, mno represents a powerful model for investigation, and a tool for future screens aimed at identifying chemical modifiers of variegate porphyria. PMID:18550261

  3. Zebrafish Models of Human Liver Development and Disease

    PubMed Central

    Wilkins, Benjamin J.; Pack, Michael

    2016-01-01

    The liver performs a large number of essential synthetic and regulatory functions that are acquired during fetal development and persist throughout life. Their disruption underlies a diverse group of heritable and acquired diseases that affect both pediatric and adult patients. Although experimental analyses used to study liver development and disease are typically performed in cell culture models or rodents, the zebrafish is increasingly used to complement discoveries made in these systems. Forward and reverse genetic analyses over the past two decades have shown that the molecular program for liver development is largely conserved between zebrafish and mammals, and that the zebrafish can be used to model heritable human liver disorders. Recent work has demonstrated that zebrafish can also be used to study the mechanistic basis of acquired liver diseases. Here, we provide a comprehensive summary of how the zebrafish has contributed to our understanding of human liver development and disease. PMID:23897685

  4. Zebrafish heart as a model for human cardiac electrophysiology

    PubMed Central

    Vornanen, Matti; Hassinen, Minna

    2016-01-01

    ABSTRACT The zebrafish (Danio rerio) has become a popular model for human cardiac diseases and pharmacology including cardiac arrhythmias and its electrophysiological basis. Notably, the phenotype of zebrafish cardiac action potential is similar to the human cardiac action potential in that both have a long plateau phase. Also the major inward and outward current systems are qualitatively similar in zebrafish and human hearts. However, there are also significant differences in ionic current composition between human and zebrafish hearts, and the molecular basis and pharmacological properties of human and zebrafish cardiac ionic currents differ in several ways. Cardiac ionic currents may be produced by non-orthologous genes in zebrafish and humans, and paralogous gene products of some ion channels are expressed in the zebrafish heart. More research on molecular basis of cardiac ion channels, and regulation and drug sensitivity of the cardiac ionic currents are needed to enable rational use of the zebrafish heart as an electrophysiological model for the human heart. PMID:26671745

  5. Adult Zebrafish model of streptococcal infection

    PubMed Central

    Phelps, Hilary A.; Runft, Donna L.

    2009-01-01

    Streptococcal pathogens cause a wide array of clinical syndromes in humans, including invasive systemic infections resulting in high mortality rates. Many of these pathogens are human specific, and therefore difficult to analyze in vivo using typical animal models, as these models rarely replicate what is observed in human infections. This unit describes the use of the zebrafish (Danio rerio) as an animal model for streptococcal infection to analyze multiple disease states. This model closely mimics the necrotizing fasciitis/myositis pathology observed in humans from a Streptococcus pyogenes infection. The use of a zoonotic pathogen, Streptococcus iniae, which replicates systemic infections caused by many streptococcal pathogens, including dissemination to the brain, is also described. Included protocols describe both intraperitoneal and intramuscular infections, as well as methods for histological and quantitative measurements of infection. PMID:19412913

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

    PubMed

    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

  7. Zebrafish (Danio rerio): A Potential Model for Toxinological Studies.

    PubMed

    Vargas, Rafael Antonio; Sarmiento, Karen; Vásquez, Isabel Cristina

    2015-10-01

    Zebrafish are an emerging basic biomedical research model that has multiple advantages compared with other research models. Given that biotoxins, such as toxins, poisons, and venoms, represent health hazards to animals and humans, a low-cost biological model that is highly sensitive to biotoxins is useful to understand the damage caused by such agents and to develop biological tests to prevent and reduce the risk of poisoning in potential cases of bioterrorism or food contamination. In this article, a narrative review of the general aspects of zebrafish as a model in basic biomedical research and various studies in the field of toxinology that have used zebrafish as a biological model are presented. This information will provide useful material to beginner students and researchers who are interested in developing toxinological studies with the zebrafish model.

  8. Using engineered endonucleases to create knockout and knockin zebrafish models.

    PubMed

    Bedell, Victoria M; Ekker, Stephen C

    2015-01-01

    Over the last few years, the technology to create targeted knockout and knockin zebrafish animals has exploded. We have gained the ability to create targeted knockouts through the use of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR associated system (CRISPR/Cas). Furthermore, using the high-efficiency TALEN system, we were able to create knockin zebrafish using a single-stranded DNA (ssDNA) protocol described here. Through the use of these technologies, the zebrafish has become a valuable vertebrate model and an excellent bridge between the invertebrate and mammalian model systems for the study of human disease.

  9. Conserved Expression Signatures between Medaka and Human Pigment Cell Tumors

    PubMed Central

    Schartl, Manfred; Kneitz, Susanne; Wilde, Brigitta; Wagner, Toni; Henkel, Christiaan V.; Spaink, Herman P.; Meierjohann, Svenja

    2012-01-01

    Aberrations in gene expression are a hallmark of cancer cells. Differential tumor-specific transcript levels of single genes or whole sets of genes may be critical for the neoplastic phenotype and important for therapeutic considerations or useful as biomarkers. As an approach to filter out such relevant expression differences from the plethora of changes noted in global expression profiling studies, we searched for changes of gene expression levels that are conserved. Transcriptomes from massive parallel sequencing of different types of melanoma from medaka were generated and compared to microarray datasets from zebrafish and human melanoma. This revealed molecular conservation at various levels between fish models and human tumors providing a useful strategy for identifying expression signatures strongly associated with disease phenotypes and uncovering new melanoma molecules. PMID:22693581

  10. Nanos3 gene targeting in medaka ES cells.

    PubMed

    Guan, Guijun; Yan, Yan; Chen, Tiansheng; Yi, Meisheng; Ni, Hong; Naruse, Kiyoshi; Nagahama, Yoshitaka; Hong, Yunhan

    2013-01-01

    Gene targeting (GT) by homologous recombination offers the best precision for genome editing in mice. nanos3 is a highly conserved gene and encodes a zinc-finger RNA binding protein essential for germ stem cell maintenance in Drosophila, zebrafish and mouse. Here we report nanos3 GT in embryonic stem (ES) cells of the fish medaka as a lower vertebrate model organism. A vector was designed for GT via homologous recombination on the basis of positive-negative selection (PNS). The ES cell line MES1 after gene transfer and PNS produced 56 colonies that were expanded into ES cell sublines. Nine sublines were GT-positive by PCR genotyping, 4 of which were homologous recombinants as revealed by Southern blot. We show that one of the 4, A15, contains a precisely targeted nanos3 allele without any random events, demonstrating the GT feasibility in medaka ES cells. Importantly, A15 retained all features of undifferentiated ES cells, including stable self-renewal, an undifferentiated phenotype, pluripotency gene expression and differentiation during chimeric embryogenesis. These results provide first evidence that the GT procedure and genuine GT on a chromosomal locus such as nanos3 do not compromise pluripotency in ES cells of a lower vertebrate.

  11. Medaka haploid embryonic stem cells.

    PubMed

    Hong, Yunhan

    2010-01-01

    The appearance of diploidy, the presence of two genomes or chromosome sets, is a fundamental hallmark of eukaryotic evolution and bisexual reproduction, because diploidy offers the basis for the bisexual life cycle, allowing for oscillation between diploid and haploid phases. Meiosis produces haploid gametes. At fertilization, male and female gametes fuse to restore diploidy in a zygote, which develops into a new life. At sex maturation, diploid cells enter into meiosis, culminating in the production of haploid gametes. Therefore, diploidy ensures pluripotency, cell proliferation, and functions, whereas haploidy is restricted only to the post-meiotic gamete phase of germline development and represents the end point of cell growth. Diploidy is advantageous for evolution. Haploidy is ideal for genetic analyses, because any recessive mutations of essential genes will show a clear phenotype in the absence of a second gene copy. Recently, my laboratory succeeded in the generation of medaka haploid embryonic stem (ES) cells capable of whole animal production. Therefore, haploidy in a vertebrate is able to support stable cell culture and pluripotency. This finding anticipates the possibility to generate haploid ES cells in other vertebrate species such as zebrafish. These medaka haploid ES cells elegantly combine haploidy and pluripotency, offering a unique yeast-like system for in vitro genetic analyses of molecular, cellular, and developmental events in various cell lineages. This chapter is aimed to describe the strategy of haploid ES cell derivation and their characteristics, and illustrate the perspectives of haploid ES cells for infertility treatment, genetic screens, and analyses.

  12. Teratogenic potential of antiepileptic drugs in the zebrafish model.

    PubMed

    Lee, Sung Hak; Kang, Jung Won; Lin, Tao; Lee, Jae Eun; Jin, Dong Il

    2013-01-01

    The zebrafish model is an attractive candidate for screening of developmental toxicity during early drug development. Antiepileptic drugs (AEDs) arouse concern for the risk of teratogenicity, but the data are limited. In this study, we evaluated the teratogenic potential of seven AEDs (carbamazepine (CBZ), ethosuximide (ETX), valproic acid (VPN), lamotrigine (LMT), lacosamide (LCM), levetiracetam (LVT), and topiramate (TPM)) in the zebrafish model. Zebrafish embryos were exposed to AEDs from initiation of gastrula (5.25 hours post-fertilization (hpf)) to termination of hatching (72 hpf) which mimic the mammalian teratogenic experimental design. The lethality and teratogenic index (TI) of AEDs were determined and the TI values of each drug were compared with the US FDA human pregnancy categories. Zebrafish model was useful screening model for teratogenic potential of antiepilepsy drugs and was in concordance with in vivo mammalian data and human clinical data.

  13. Teratogenic Potential of Antiepileptic Drugs in the Zebrafish Model

    PubMed Central

    Lee, Sung Hak; Kang, Jung Won; Lin, Tao; Lee, Jae Eun; Jin, Dong Il

    2013-01-01

    The zebrafish model is an attractive candidate for screening of developmental toxicity during early drug development. Antiepileptic drugs (AEDs) arouse concern for the risk of teratogenicity, but the data are limited. In this study, we evaluated the teratogenic potential of seven AEDs (carbamazepine (CBZ), ethosuximide (ETX), valproic acid (VPN), lamotrigine (LMT), lacosamide (LCM), levetiracetam (LVT), and topiramate (TPM)) in the zebrafish model. Zebrafish embryos were exposed to AEDs from initiation of gastrula (5.25 hours post-fertilization (hpf)) to termination of hatching (72 hpf) which mimic the mammalian teratogenic experimental design. The lethality and teratogenic index (TI) of AEDs were determined and the TI values of each drug were compared with the US FDA human pregnancy categories. Zebrafish model was useful screening model for teratogenic potential of antiepilepsy drugs and was in concordance with in vivo mammalian data and human clinical data. PMID:24324971

  14. Think Small: Zebrafish as a Model System of Human Pathology

    PubMed Central

    Goldsmith, J. R.; Jobin, Christian

    2012-01-01

    Although human pathologies have mostly been modeled using higher mammal systems such as mice, the lower vertebrate zebrafish has gained tremendous attention as a model system. The advantages of zebrafish over classical vertebrate models are multifactorial and include high genetic and organ system homology to humans, high fecundity, external fertilization, ease of genetic manipulation, and transparency through early adulthood that enables powerful imaging modalities. This paper focuses on four areas of human pathology that were developed and/or advanced significantly in zebrafish in the last decade. These areas are (1) wound healing/restitution, (2) gastrointestinal diseases, (3) microbe-host interactions, and (4) genetic diseases and drug screens. Important biological processes and pathologies explored include wound-healing responses, pancreatic cancer, inflammatory bowel diseases, nonalcoholic fatty liver disease, and mycobacterium infection. The utility of zebrafish in screening for novel genes important in various pathologies such as polycystic kidney disease is also discussed. PMID:22701308

  15. Targeted mutation of zebrafish fga models human congenital afibrinogenemia

    PubMed Central

    Fish, Richard J.; Di Sanza, Corinne

    2014-01-01

    Mutations in the human fibrinogen genes can lead to the absence of circulating fibrinogen and cause congenital afibrinogenemia. This rare bleeding disorder is associated with a variable phenotype, which may be influenced by environment and genotype. Here, we present a zebrafish model of afibrinogenemia. We introduced targeted mutations into the zebrafish fga gene using zinc finger nuclease technology. Animals carrying 3 distinct frameshift mutations in fga were raised and bred to produce homozygous mutants. Using a panel of anti-zebrafish fibrinogen antibodies, fibrinogen was undetectable in plasma preparations from homozygous mutant fish. We observed hemorrhaging in fga mutants and reduced survival compared with control animals. This model will now serve in the search for afibrinogenemia modifying genes or agents and, to our knowledge, is the first transmissible zebrafish model of a defined human bleeding disorder. PMID:24553182

  16. Targeted mutation of zebrafish fga models human congenital afibrinogenemia.

    PubMed

    Fish, Richard J; Di Sanza, Corinne; Neerman-Arbez, Marguerite

    2014-04-03

    Mutations in the human fibrinogen genes can lead to the absence of circulating fibrinogen and cause congenital afibrinogenemia. This rare bleeding disorder is associated with a variable phenotype, which may be influenced by environment and genotype. Here, we present a zebrafish model of afibrinogenemia. We introduced targeted mutations into the zebrafish fga gene using zinc finger nuclease technology. Animals carrying 3 distinct frameshift mutations in fga were raised and bred to produce homozygous mutants. Using a panel of anti-zebrafish fibrinogen antibodies, fibrinogen was undetectable in plasma preparations from homozygous mutant fish. We observed hemorrhaging in fga mutants and reduced survival compared with control animals. This model will now serve in the search for afibrinogenemia modifying genes or agents and, to our knowledge, is the first transmissible zebrafish model of a defined human bleeding disorder.

  17. The zebrafish as a model for complex tissue regeneration

    PubMed Central

    Gemberling, Matthew; Bailey, Travis J.; Hyde, David R.; Poss, Kenneth D.

    2013-01-01

    For centuries, philosophers and scientists have been fascinated by the principles and implications of regeneration in lower vertebrate species. Two features have made zebrafish an informative model system for determining mechanisms of regenerative events. First, they are highly regenerative, able to regrow amputated fins, as well as a lesioned brain, retina, spinal cord, heart, and other tissues. Second, they are amenable to both forward and reverse genetic approaches, with a research toolset regularly updated by an expanding community of zebrafish researchers. Zebrafish studies have helped identify new mechanistic underpinnings of regeneration in multiple tissues, and in some cases have served as a guide for contemplating regenerative strategies in mammals. Here, we review the recent history of zebrafish as a genetic model system for understanding how and why tissue regeneration occurs. PMID:23927865

  18. REVIEW: Zebrafish: A Renewed Model System For Functional Genomics

    NASA Astrophysics Data System (ADS)

    Wen, Xiao-Yan

    2008-01-01

    In the post genome era, a major goal in molecular biology is to determine the function of the many thousands of genes present in the vertebrate genome. The zebrafish (Danio rerio) provides an almost ideal genetic model to identify the biological roles of these novel genes, in part because their embryos are transparent and develop rapidly. The zebrafish has many advantages over mouse for genome-wide mutagenesis studies, allowing for easier, cheaper and faster functional characterization of novel genes in the vertebrate genome. Many molecular research tools such as chemical mutagenesis, transgenesis, gene trapping, gene knockdown, TILLING, gene targeting, RNAi and chemical genetic screen are now available in zebrafish. Combining all the forward, reverse, and chemical genetic tools, it is expected that zebrafish will make invaluable contribution to vertebrate functional genomics in functional annotation of the genes, modeling human diseases and drug discoveries.

  19. The zebrafish as a model for complex tissue regeneration.

    PubMed

    Gemberling, Matthew; Bailey, Travis J; Hyde, David R; Poss, Kenneth D

    2013-11-01

    For centuries, philosophers and scientists have been fascinated by the principles and implications of regeneration in lower vertebrate species. Two features have made zebrafish an informative model system for determining mechanisms of regenerative events. First, they are highly regenerative, able to regrow amputated fins, as well as a lesioned brain, retina, spinal cord, heart, and other tissues. Second, they are amenable to both forward and reverse genetic approaches, with a research toolset regularly updated by an expanding community of zebrafish researchers. Zebrafish studies have helped identify new mechanistic underpinnings of regeneration in multiple tissues and, in some cases, have served as a guide for contemplating regenerative strategies in mammals. Here, we review the recent history of zebrafish as a genetic model system for understanding how and why tissue regeneration occurs.

  20. Fit for consumption: zebrafish as a model for tuberculosis.

    PubMed

    Cronan, Mark R; Tobin, David M

    2014-07-01

    Despite efforts to generate new vaccines and antibiotics for tuberculosis, the disease remains a public health problem worldwide. The zebrafish Danio rerio has emerged as a useful model to investigate mycobacterial pathogenesis and treatment. Infection of zebrafish with Mycobacterium marinum, the closest relative of the Mycobacterium tuberculosis complex, recapitulates many aspects of human tuberculosis. The zebrafish model affords optical transparency, abundant genetic tools and in vivo imaging of the progression of infection. Here, we review how the zebrafish-M. marinum system has been deployed to make novel observations about the role of innate immunity, the tuberculous granuloma, and crucial host and bacterial genes. Finally, we assess how these findings relate to human disease and provide a framework for novel strategies to treat tuberculosis. © 2014. Published by The Company of Biologists Ltd.

  1. The zebrafish as a model to study intestinal inflammation.

    PubMed

    Brugman, Sylvia

    2016-11-01

    Starting out as a model for developmental biology, during the last decade, zebrafish have also gained the attention of the immunologists and oncologists. Due to its small size, high fecundity and full annotation of its genome, the zebrafish is an attractive model system. The fact that fish are transparent early in life combined with the growing list of immune cell reporter fish, enables in vivo tracking of immune responses in a complete organism. Since zebrafish develop ex utero from a fertilized egg, immune development can be monitored from the start of life. Given that several gut functions and immune genes are conserved between zebrafish and mammals, the zebrafish is an interesting model organism to investigate fundamental processes underlying intestinal inflammation and injury. This review will first provide some background on zebrafish intestinal development, bacterial colonization and immunity, showing the similarities and differences compared to mammals. This will be followed by an overview of the existing models for intestinal disease, and concluded by future perspectives in light of the newest technologies and insights. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  2. Medaka fish exhibits longevity gender gap, a natural drop in estrogen and telomere shortening during aging: a unique model for studying sex-dependent longevity

    PubMed Central

    2013-01-01

    Introduction Females having a longer telomere and lifespan than males have been documented in many animals. Such linkage however has never been reported in fish. Progressive shortening of telomere length is an important aging mechanism. Mounting in vitro evidence has shown that telomere shortening beyond a critical length triggered replicative senescence or cell death. Estrogen has been postulated as a key factor contributing to maintenance of telomere and sex-dependent longevity in animals. This postulation remains unproven due to the lack of a suitable animal system for testing. Here, we introduce a teleost model, the Japanese medaka Oryzias latipes, which shows promise for research into the molecular mechanism(s) controlling sex difference in aging. Results Using the medaka, we demonstrate for the first time in teleost that (i) sex differences (female > male) in telomere length and longevity also exist in fish, and (ii) a natural, ‘menopause’-like decline of plasma estrogen was evident in females during aging. Estrogen levels significantly correlated with telomerase activity as well as telomere length in female organs (not in males), suggesting estrogen could modulate telomere length via telomerase activation in a sex -specific manner. A hypothetical in vivo ‘critical’ terminal restriction fragment (TRF, representing telomere) length of approximately 4 kb was deduced in medaka liver for prediction of organismal mortality, which is highly comparable with that for human cells. An age conversion model was also established to enable age translation between medaka (in months) and human (in years). These novel tools are useful for future research on comparative biology of aging using medaka. Conclusion The striking similarity in estrogen profile between aging female O. latipes and women enables studying the influence of “postmenopausal” decline of estrogen on telomere and longevity without the need of invasive ovariectomy. Medaka fish is advantageous

  3. Persistent impaired glucose metabolism in a zebrafish hyperglycemia model.

    PubMed

    Capiotti, Katiucia Marques; Antonioli, Régis; Kist, Luiza Wilges; Bogo, Maurício Reis; Bonan, Carla Denise; Da Silva, Rosane Souza

    2014-05-01

    Diabetes mellitus (DM) affects over 10% of the world's population. Hyperglycemia is the main feature for the diagnosis of this disease. The zebrafish (Danio rerio) is an established model organism for the study of various metabolic diseases. In this paper, hyperglycemic zebrafish, when immersed in a 111 mM glucose solution for 14 days, developed increased glycation of proteins from the eyes, decreased mRNA levels of insulin receptors in the muscle, and a reversion of high blood glucose level after treatment with anti-diabetic drugs (glimepiride and metformin) even after 7 days of glucose withdrawal. Additionally, hyperglycemic zebrafish developed an impaired response to exogenous insulin, which was recovered after 7 days of glucose withdrawal. These data suggest that the exposure of adult zebrafish to high glucose concentration is able to induce persistent metabolic changes probably underlined by a hyperinsulinemic state and impaired peripheral glucose metabolism.

  4. A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution.

    PubMed Central

    Naruse, K; Fukamachi, S; Mitani, H; Kondo, M; Matsuoka, T; Kondo, S; Hanamura, N; Morita, Y; Hasegawa, K; Nishigaki, R; Shimada, A; Wada, H; Kusakabe, T; Suzuki, N; Kinoshita, M; Kanamori, A; Terado, T; Kimura, H; Nonaka, M; Shima, A

    2000-01-01

    We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes. PMID:10747068

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

    PubMed Central

    Harrison, Nicholas R.; Laroche, Fabrice J.F.; Gutierrez, Alejandro

    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. PMID:27165361

  6. Life-cycle experiments of medaka fish aboard the international space station.

    PubMed

    Ijiri, Kenichi

    2003-01-01

    Fish are the most likely candidates to be the first vertebrate to live their life cycle aboard the International Space Station (ISS). In the space-shuttle experiment using medaka, the fry born in space had the same number of germ cells as the ground control fish, and these germ cells later developed to produce the offspring on the ground. Fry hatched in space did not exhibit any looping behavior regardless of their strain, visual acuity, etc. The aquatic habitat (AQH) is a space habitat designed for long-term breeding of medaka, zebrafish and Xenopus, and recent advancements in this hardware also support fish life-cycle experiments. From the crosses between two strains, fish having good eyesight and less sensitivity to gravity were obtained, and their tolerance to microgravity was tested by parabolic flight using an airplane. The fish exhibited less looping and no differences in degree of looping between light and dark conditions. These are possible candidates for the first adult medaka (parent fish) to start a life cycle aboard ISS. Embryos were treated with a three-dimensional clinostat. Such simulated microgravity caused no differences in tissue architecture or in gene expression within the retina, nor in formation of cartilage (head skeleton). Otolith formation in embryos and fry was investigated for wild-type and mutant (ha) medaka. The ha embryos could not form utricular otoliths. They formed saccular otoliths but with a delay. Fry of the mutant fish lacking the utricular otoliths are highly light-dependent at the time of hatching, showing a perfect dorsal-light response (DLR). As they grow, they eventually shift from being light dependent to gravity dependent. Continuous treatment of the fry with altered light direction suppressed this shift to gravity dependence. Being less dependent on gravity, these fish can serve as model fish in studying the differences expected for the fish that have experienced a life cycle in microgravity.

  7. Analysing regenerative potential in zebrafish models of congenital muscular dystrophy.

    PubMed

    Wood, A J; Currie, P D

    2014-11-01

    The congenital muscular dystrophies (CMDs) are a clinically and genetically heterogeneous group of muscle disorders. Clinically hypotonia is present from birth, with progressive muscle weakness and wasting through development. For the most part, CMDs can mechanistically be attributed to failure of basement membrane protein laminin-α2 sufficiently binding with correctly glycosylated α-dystroglycan. The majority of CMDs therefore arise as the result of either a deficiency of laminin-α2 (MDC1A) or hypoglycosylation of α-dystroglycan (dystroglycanopathy). Here we consider whether by filling a regenerative medicine niche, the zebrafish model can address the present challenge of delivering novel therapeutic solutions for CMD. In the first instance the readiness and appropriateness of the zebrafish as a model organism for pioneering regenerative medicine therapies in CMD is analysed, in particular for MDC1A and the dystroglycanopathies. Despite the recent rapid progress made in gene editing technology, these approaches have yet to yield any novel zebrafish models of CMD. Currently the most genetically relevant zebrafish models to the field of CMD, have all been created by N-ethyl-N-nitrosourea (ENU) mutagenesis. Once genetically relevant models have been established the zebrafish has several important facets for investigating the mechanistic cause of CMD, including rapid ex vivo development, optical transparency up to the larval stages of development and relative ease in creating transgenic reporter lines. Together, these tools are well suited for use in live-imaging studies such as in vivo modelling of muscle fibre detachment. Secondly, the zebrafish's contribution to progress in effective treatment of CMD was analysed. Two approaches were identified in which zebrafish could potentially contribute to effective therapies. The first hinges on the augmentation of functional redundancy within the system, such as upregulating alternative laminin chains in the candyfloss

  8. Conservation and Early Expression of Zebrafish Tyrosine Kinases Support the Utility of Zebrafish as a Model for Tyrosine Kinase Biology

    PubMed Central

    Challa, Anil Kumar

    2013-01-01

    Abstract Tyrosine kinases have significant roles in cell growth, apoptosis, development, and disease. To explore the use of zebrafish as a vertebrate model for tyrosine kinase signaling and to better understand their roles, we have identified all of the tyrosine kinases encoded in the zebrafish genome and quantified RNA expression of selected tyrosine kinases during early development. Using profile hidden Markov model analysis, we identified 122 zebrafish tyrosine kinase genes and proposed unambiguous gene names where needed. We found them to be organized into 39 nonreceptor and 83 receptor type, and 30 families consistent with human tyrosine kinase family assignments. We found five human tyrosine kinase genes (epha1, bmx, fgr, srm, and insrr) with no identifiable zebrafish ortholog, and one zebrafish gene (yrk) with no identifiable human ortholog. We also found that receptor tyrosine kinase genes were duplicated more often than nonreceptor tyrosine kinase genes in zebrafish. We profiled expression levels of 30 tyrosine kinases representing all families using direct digital detection at different stages during the first 24 hours of development. The profiling experiments clearly indicate regulated expression of tyrosine kinases in the zebrafish, suggesting their role during early embryonic development. In summary, our study has resulted in the first comprehensive description of the zebrafish tyrosine kinome. PMID:23234507

  9. Conservation and early expression of zebrafish tyrosine kinases support the utility of zebrafish as a model for tyrosine kinase biology.

    PubMed

    Challa, Anil Kumar; Chatti, Kiranam

    2013-09-01

    Tyrosine kinases have significant roles in cell growth, apoptosis, development, and disease. To explore the use of zebrafish as a vertebrate model for tyrosine kinase signaling and to better understand their roles, we have identified all of the tyrosine kinases encoded in the zebrafish genome and quantified RNA expression of selected tyrosine kinases during early development. Using profile hidden Markov model analysis, we identified 122 zebrafish tyrosine kinase genes and proposed unambiguous gene names where needed. We found them to be organized into 39 nonreceptor and 83 receptor type, and 30 families consistent with human tyrosine kinase family assignments. We found five human tyrosine kinase genes (epha1, bmx, fgr, srm, and insrr) with no identifiable zebrafish ortholog, and one zebrafish gene (yrk) with no identifiable human ortholog. We also found that receptor tyrosine kinase genes were duplicated more often than nonreceptor tyrosine kinase genes in zebrafish. We profiled expression levels of 30 tyrosine kinases representing all families using direct digital detection at different stages during the first 24 hours of development. The profiling experiments clearly indicate regulated expression of tyrosine kinases in the zebrafish, suggesting their role during early embryonic development. In summary, our study has resulted in the first comprehensive description of the zebrafish tyrosine kinome.

  10. A jump persistent turning walker to model zebrafish locomotion

    PubMed Central

    Mwaffo, Violet; Anderson, Ross P.; Butail, Sachit; Porfiri, Maurizio

    2015-01-01

    Zebrafish are gaining momentum as a laboratory animal species for the investigation of several functional and dysfunctional biological processes. Mathematical models of zebrafish behaviour are expected to considerably aid in the design of hypothesis-driven studies by enabling preliminary in silico tests that can be used to infer possible experimental outcomes without the use of zebrafish. This study is motivated by observations of sudden, drastic changes in zebrafish locomotion in the form of large deviations in turn rate. We demonstrate that such deviations can be captured through a stochastic mean reverting jump diffusion model, a process that is commonly used in financial engineering to describe large changes in the price of an asset. The jump process-based model is validated on trajectory data of adult subjects swimming in a shallow circular tank obtained from an overhead camera. Through statistical comparison of the empirical distribution of the turn rate against theoretical predictions, we demonstrate the feasibility of describing zebrafish as a jump persistent turning walker. The critical role of the jump term is assessed through comparison with a simplified mean reversion diffusion model, which does not allow for describing the heavy-tailed distributions observed in the fish turn rate. PMID:25392396

  11. A jump persistent turning walker to model zebrafish locomotion.

    PubMed

    Mwaffo, Violet; Anderson, Ross P; Butail, Sachit; Porfiri, Maurizio

    2015-01-06

    Zebrafish are gaining momentum as a laboratory animal species for the investigation of several functional and dysfunctional biological processes. Mathematical models of zebrafish behaviour are expected to considerably aid in the design of hypothesis-driven studies by enabling preliminary in silico tests that can be used to infer possible experimental outcomes without the use of zebrafish. This study is motivated by observations of sudden, drastic changes in zebrafish locomotion in the form of large deviations in turn rate. We demonstrate that such deviations can be captured through a stochastic mean reverting jump diffusion model, a process that is commonly used in financial engineering to describe large changes in the price of an asset. The jump process-based model is validated on trajectory data of adult subjects swimming in a shallow circular tank obtained from an overhead camera. Through statistical comparison of the empirical distribution of the turn rate against theoretical predictions, we demonstrate the feasibility of describing zebrafish as a jump persistent turning walker. The critical role of the jump term is assessed through comparison with a simplified mean reversion diffusion model, which does not allow for describing the heavy-tailed distributions observed in the fish turn rate.

  12. Analysis of the Retina in the Zebrafish Model

    PubMed Central

    Avanesov, Andrei; Malicki, Jarema

    2014-01-01

    The zebrafish is one of the leading models for the analysis of the vertebrate visual system. A wide assortment of molecular, genetic, and cell biological approaches is available to study zebrafish visual system development and function. As new techniques become available, genetic analysis and imaging continue to be the strengths of the zebrafish model. In particular, recent developments in the use of transposons and zinc finger nucleases to produce new generations of mutant strains enhance both forward and reverse genetic analysis. Similarly, the imaging of developmental and physiological processes benefits from a wide assortment of fluorescent proteins and the ways to express them in the embryo. The zebrafish is also highly attractive for high-throughput screening of small molecules, a promising strategy to search for compounds with therapeutic potential. Here we discuss experimental approaches used in the zebrafish model to study morpho−genetic transformations, cell fate decisions, and the differentiation of fine morphological features that ultimately lead to the formation of the functional vertebrate visual system. PMID:21111217

  13. ZFIN, the Zebrafish Model Organism Database: updates and new directions

    PubMed Central

    Ruzicka, Leyla; Bradford, Yvonne M.; Frazer, Ken; Howe, Douglas G.; Paddock, Holly; Ramachandran, Sridhar; Singer, Amy; Toro, Sabrina; Van Slyke, Ceri E.; Eagle, Anne E.; Fashena, David; Kalita, Patrick; Knight, Jonathan; Mani, Prita; Martin, Ryan; Moxon, Sierra A. T.; Pich, Christian; Schaper, Kevin; Shao, Xiang; Westerfield, Monte

    2015-01-01

    The Zebrafish Model Organism Database (ZFIN; http://zfin.org) is the central resource for genetic and genomic data from zebrafish (Danio rerio) research. ZFIN staff curate detailed information about genes, mutants, genotypes, reporter lines, sequences, constructs, antibodies, knockdown reagents, expression patterns, phenotypes, gene product function, and orthology from publications. Researchers can submit mutant, transgenic, expression, and phenotype data directly to ZFIN and use the ZFIN Community Wiki to share antibody and protocol information. Data can be accessed through topic-specific searches, a new site-wide search, and the data-mining resource ZebrafishMine (http://zebrafishmine.org). Data download and web service options are also available. ZFIN collaborates with major bioinformatics organizations to verify and integrate genomic sequence data, provide nomenclature support, establish reciprocal links and participate in the development of standardized structured vocabularies (ontologies) used for data annotation and searching. ZFIN-curated gene, function, expression, and phenotype data are available for comparative exploration at several multi-species resources. The use of zebrafish as a model for human disease is increasing. ZFIN is supporting this growing area with three major projects: adding easy access to computed orthology data from gene pages, curating details of the gene expression pattern changes in mutant fish, and curating zebrafish models of human diseases. PMID:26097180

  14. Aquatic blues: modeling depression and antidepressant action in zebrafish.

    PubMed

    Nguyen, Michael; Stewart, Adam Michael; Kalueff, Allan V

    2014-12-03

    Depression is a serious psychiatric condition affecting millions of patients worldwide. Unipolar depression is characterized by low mood, anhedonia, social withdrawal and other severely debilitating psychiatric symptoms. Bipolar disorder manifests in alternating depressed mood and 'hyperactive' manic/hypomanic states. Animal experimental models are an invaluable tool for research into the pathogenesis of bipolar/unipolar depression, and for the development of potential treatments. Due to their high throughput value, genetic tractability, low cost and quick reproductive cycle, zebrafish (Danio rerio) have emerged as a promising new model species for studying brain disorders. Here, we discuss the developing utility of zebrafish for studying depression disorders, and outline future areas of research in this field. We argue that zebrafish represent a useful model organism for studying depression and its behavioral, genetic and physiological mechanisms, as well as for anti-depressant drug discovery.

  15. Zebrafish: A Model for the Study of Addiction Genetics

    PubMed Central

    Klee, Eric W; Schneider, Henning; Clark, Karl; Cousin, Margot; Ebbert, Jon; Hooten, Michael; Karpyak, Victor; Warner, David; Ekker, Stephen

    2013-01-01

    Drug abuse and dependence are multifaceted disorders with complex genetic underpinnings. Identifying specific genetic correlates is challenging and may be more readily accomplished by defining endophenotypes specific for addictive disorders. Symptoms and syndromes, including acute drug response, consumption, preference, and withdrawal, are potential endophenotypes characterizing addiction that have been investigated using model organisms. We present a review of major genes involved in serotonergic, dopaminergic, GABAergic, and adrenoreceptor signaling that are considered to be directly involved in nicotine, opioid, cannabinoid, and ethanol use and dependence. The zebrafish genome encodes likely homologs of the vast majority of these loci. We also review the known expression patterns of these genes in zebrafish. The information presented in this review provides support for the use of zebrafish as a viable model for studying genetic factors related to drug addiction. Expansion of investigations into drug response using model organisms holds the potential to advance our understanding of drug response and addiction in humans. PMID:22207143

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

    PubMed

    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.

  17. Graph Theoretical Model of a Sensorimotor Connectome in Zebrafish

    PubMed Central

    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. PMID:22624008

  18. Zebrafish as a Model System to Screen Radiation Modifiers

    PubMed Central

    Hwang, Misun; Yong, Cha; Moretti, Luigi; Lu, Bo

    2007-01-01

    Zebrafish (Danio rerio) is a bona fide vertebrate model system for understanding human diseases. It allows the transparent visualization of the effects of ionizing radiation and the convenient testing of potential radioprotectors with morpholino-modified oligonucleotides (MO) knockdown. Furthermore, various reverse and forward genetic methods are feasible to decipher novel genetic modifiers of radioprotection. Examined in the review are the radioprotective effects of the proposed radiomodifiers Nanoparticle DF-1 (C-Sixty, Inc., Houston, TX) and Amifostine (WR-2721, Ethyol), the DNA repair proteins Ku80 and ATM, as well as the transplanted hematopoietic stem cells in irradiated zebrafish. The presence of any of these sufficiently rescued the radiation-induced damages in zebrafish, while its absence resulted in mutagenic phenotypes as well as an elevation of time- and dose-dependent radiation-induced apoptosis. Radiosensitizers Flavopiridol and AG1478, both of which block progression into the radioresistant S phase of the cell cycle, have also been examined in zebrafish. Zebrafish has indeed become a favorite model system to test for radiation modifiers that can potentially be used for radiotherapeutic purposes in humans. PMID:19412436

  19. Modeling Pancreatic Endocrine Cell Adaptation and Diabetes in the Zebrafish

    PubMed Central

    Maddison, Lisette A.; Chen, Wenbiao

    2017-01-01

    Glucose homeostasis is an important element of energy balance and is conserved in organisms from fruit fly to mammals. Central to the control of circulating glucose levels in vertebrates are the endocrine cells of the pancreas, particularly the insulin-producing β-cells and the glucagon producing α-cells. A feature of α- and β-cells is their plasticity, an ability to adapt, in function and number as a response to physiological and pathophysiological conditions of increased hormone demand. The molecular mechanisms underlying these adaptive responses that maintain glucose homeostasis are incompletely defined. The zebrafish is an attractive model due to the low cost, high fecundity, and amenability to genetic and compound screens, and mechanisms governing the development of the pancreatic endocrine cells are conserved between zebrafish and mammals. Post development, both β- and α-cells of zebrafish display plasticity as in mammals. Here, we summarize the studies of pancreatic endocrine cell adaptation in zebrafish. We further explore the utility of the zebrafish as a model for diabetes, a relevant topic considering the increase in diabetes in the human population. PMID:28184214

  20. Use of Medaka in Toxicity Testing

    PubMed Central

    Cowden, John; Hinton, David E.; Johnson, Rodney; Flynn, Kevin; Hardman, Ronald C.; Yuen, Bonny; Law, Sheran; Kullman, Seth W.; Au, Doris W.T.

    2015-01-01

    Small aquarium fishes are increasingly used as animal models, and one of these, Japanese Medaka (Oryzias latipes), is frequently utilized for toxicity testing. While these vertebrates have many similarities with their terrestrial counterparts, there are differences that must be considered if these organisms are to be used to their highest potential. Testing commonly may employ either the developing embryo or adults; both are easy to use and to work with. We present here three main protocols to illustrate the utility and breadth of toxicity testing possible using medaka fish. The first protocol assesses neurotoxicity in developing embryos. The second protocol describes the sexual genotyping of medaka to evaluate toxicant effects on sexual phenotype after treatment with endocrine disrupting chemicals. The third protocol assesses hepatotoxicity in adult fish after treatment with a model hepatotoxicant. The methods run the gamut from immunohistology through PCR to basic histological techniques. PMID:20922755

  1. Exploring Hallucinogen Pharmacology and Psychedelic Medicine with Zebrafish Models.

    PubMed

    Kyzar, Evan J; Kalueff, Allan V

    2016-10-01

    After decades of sociopolitical obstacles, the field of psychiatry is experiencing a revived interest in the use of hallucinogenic agents to treat brain disorders. Along with the use of ketamine for depression, recent pilot studies have highlighted the efficacy of classic serotonergic hallucinogens, such as lysergic acid diethylamide and psilocybin, in treating addiction, post-traumatic stress disorder, and anxiety. However, many basic pharmacological and toxicological questions remain unanswered with regard to these compounds. In this study, we discuss psychedelic medicine as well as the behavioral and toxicological effects of hallucinogenic drugs in zebrafish. We emphasize this aquatic organism as a model ideally suited to assess both the potential toxic and therapeutic effects of major known classes of hallucinogenic compounds. In addition, novel drugs with hallucinogenic properties can be efficiently screened using zebrafish models. Well-designed preclinical studies utilizing zebrafish can contribute to the reemerging treatment paradigm of psychedelic medicine, leading to new avenues of clinical exploration for psychiatric disorders.

  2. Zebrafish as a model system to study heritable skin diseases.

    PubMed

    Li, Qiaoli; Uitto, Jouni

    2013-01-01

    Heritable skin diseases represent a broad spectrum of clinical manifestations due to mutations in ∼500 different genes. A number of model systems have been developed to advance our understanding of the pathomechanisms of genodermatoses. Zebrafish (Danio rerio), a freshwater vertebrate, has a well-characterized genome, the expression of which can be easily manipulated. The larvae develop rapidly, with all major organs having largely developed by 5-6 days post-fertilization, including the skin which consists at that stage of the epidermis comprising two cell layers and separated from the dermal collagenous matrix by a basement membrane zone. Here, we describe the use of morpholino-based antisense oligonucleotides to knockdown the expression of specific genes in zebrafish and to examine the consequent knockdown efficiency and skin phenotypes. Zebrafish can provide a useful model system to study heritable skin diseases.

  3. Using engineered endonucleases to create knockout and knockin zebrafish models

    PubMed Central

    Bedell, Victoria M.; Ekker, Stephen C.

    2015-01-01

    Summary Over the last few years, the technology to create targeted knockout and knockin zebrafish animals has exploded. We have gained the ability to create targeted knockouts through the use of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR associated system (CRISPR/Cas). Furthermore, using the high-efficiency TALEN system, we were able to create knockin zebrafish using a single-stranded DNA (ssDNA) protocol described here. Through the use of these technologies, the zebrafish has become a valuable vertebrate model and an excellent bridge between the invertebrate and mammalian model systems for the study of human disease. PMID:25408414

  4. Zebrafish (Danio rerio) embryos as a model for testing proteratogens.

    PubMed

    Weigt, Stefan; Huebler, Nicole; Strecker, Ruben; Braunbeck, Thomas; Broschard, Thomas H

    2011-03-15

    Zebrafish embryos have been shown to be a useful model for the detection of direct acting teratogens. This communication presents a protocol for a 3-day in vitro zebrafish embryo teratogenicity assay and describes results obtained for 10 proteratogens: 2-acetylaminofluorene, benzo[a]pyrene, aflatoxin B(1), carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in structure, origin, metabolism and water solubility. Apart from 2-acetylaminofluorene, which mainly produces lethal effects, all proteratogens tested were teratogenic in zebrafish embryos exposed for 3 days. The test substances and/or the substance class produced characteristic patterns of fingerprint endpoints. Several substances produced effects that could be identified already at 1 dpf (days post fertilization), whereas the effects of others could only be identified unambiguously after hatching at ≥ 3 dpf. The LC₅₀ and EC₅₀ values were used to calculate the teratogenicity index (TI) for the different substances, and the EC₂₀ values were related to human plasma concentrations. Results lead to the conclusion that zebrafish embryos are able to activate proteratogenic substances without addition of an exogenous metabolic activation system. Moreover, the teratogenic effects were observed at concentrations relevant to human exposure data. Along with other findings, our results indicate that zebrafish embryos are a useful alternative method for traditional teratogenicity testing with mammalian species.

  5. Zebrafish as a Model to Investigate Dynamin 2-Related Diseases

    PubMed Central

    Bragato, Cinzia; Gaudenzi, Germano; Blasevich, Flavia; Pavesi, Giulio; Maggi, Lorenzo; Giunta, Michele; Cotelli, Franco; Mora, Marina

    2016-01-01

    Mutations in the dynamin-2 gene (DNM2) cause autosomal dominant centronuclear myopathy (CNM) and dominant intermediate Charcot-Marie-Tooth (CMT) neuropathy type B (CMTDIB). As the relation between these DNM2-related diseases is poorly understood, we used zebrafish to investigate the effects of two different DNM2 mutations. First we identified a new alternatively spliced zebrafish dynamin-2a mRNA (dnm2a-v2) with greater similarity to human DNM2 than the deposited sequence. Then we knocked-down the zebrafish dnm2a, producing defects in muscle morphology. Finally, we expressed two mutated DNM2 mRNA by injecting zebrafish embryos with human mRNAs carrying the R522H mutation, causing CNM, or the G537C mutation, causing CMT. Defects arose especially in secondary motor neuron formation, with incorrect branching in embryos injected with CNM-mutated mRNA, and total absence of branching in those injected with CMT-mutated mRNA. Muscle morphology in embryos injected with CMT-mutated mRNA appeared less regularly organized than in those injected with CNM-mutated mRNA. Our results showing, a continuum between CNM and CMTDIB phenotypes in zebrafish, similarly to the human conditions, confirm this animal model to be a powerful tool to investigate mutations of DNM2 in vivo. PMID:26842864

  6. Orthotopic models of pediatric brain tumors in zebrafish

    PubMed Central

    Eden, Christopher J.; Ju, Bensheng; Murugesan, Mohankumar; Phoenix, Timothy; Nimmervoll, Birgit; Tong, Yiai; Ellison, David W.; Finkelstein, David; Wright, Karen; Boulos, Nidal; Dapper, Jason; Thiruvenkatam, Radhika; Lessman, Charles; Taylor, Michael R.; Gilbertson, Richard J.

    2014-01-01

    High-throughput screens (HTS) of compound toxicity against cancer cells can identify thousands of potential new drug-leads. But only limited numbers of these compounds can progress to expensive and labor intensive efficacy studies in mice, creating a ‘bottle-neck’ in the drug development pipeline. Approaches that triage drug-leads for further study are greatly needed. Here, we provide an intermediary platform between HTS and mice by adapting mouse models of pediatric brain tumors to grow as orthotopic xenografts in the brains of zebrafish. Freshly isolated mouse ependymoma, glioma and choroid plexus carcinoma cells expressing red fluorescence protein (RFP) were conditioned to grow at 34°C. Conditioned tumor cells were then transplanted orthotopically into the brains of zebrafish acclimatized to ambient temperatures of 34°C. Live in vivo fluorescence imaging identified robust, quantifiable and reproducible brain tumor growth as well as spinal metastasis in zebrafish. All tumor xenografts in zebrafish retained the histological characteristics of the corresponding parent mouse tumor and efficiently recruited fish endothelial cells to form a tumor vasculature. Finally, by treating zebrafish harboring ERBB2-driven gliomas with an appropriate cytotoxic chemotherapy (5-fluorouracil) or tyrosine kinase inhibitor (Erlotinib), we show that these models can effectively assess drug efficacy. Our data demonstrate, for the first time, that mouse brain tumors can grow orthtopically in fish and serve as a platform to study drug efficacy. Since large cohorts of brain tumor bearing zebrafish can be generated rapidly and inexpensively, these models may serve as a powerful tool to triage drug-leads from HTS for formal efficacy testing in mice. PMID:24747973

  7. Vascular wall shear stress in zebrafish model of early atherosclerosis

    NASA Astrophysics Data System (ADS)

    Choi, Woorak; Seo, Eunseok; Yeom, Eunseop; Lee, Sang Joon

    2016-11-01

    Although atherosclerosis is a multifactorial disease, the role of hemodynamic force has strong influence on the outbreak of the disease. Low and oscillating wall shear stress (WSS) is associated with the incidence of atherosclerosis. Many researchers have investigated relationships between WSS and the occurrence of atherosclerosis using in vitro and in vivo models. However, these models possess technological limitations in mimicking real biophysiological conditions and monitoring the temporal progression of atherosclerosis. In this study, a hypercholesterolaemic zebrafish model was established as a novel model to resolve these technical limitations. WSS in blood vessels of 15 days post-fertilisation zebrafish was measured using a micro PIV technique, and the spatial distribution of lipids inside blood vessels was quantitatively visualized using a confocal microscopy. As a result, lipids are mainly deposited in the regions of low WSS. The oscillating WSS is not induced by blood flows in the zebrafish disease model. The present hypercholesterolaemic zebrafish model would be useful for understanding the effect of WSS on the early stage of atherosclerosis. This work was supported by the National Research Foundation of Korea (NRF) under a Grant funded by the Korean government (MSIP) (No. 2008-0061991).

  8. Zebrafish Egg Infection Model for Studying Candida albicans Adhesion Factors

    PubMed Central

    Chen, Yin-Zhi; Yang, Yun-Liang; Chu, Wen-Li; You, May-Su; Lo, Hsiu-Jung

    2015-01-01

    Disseminated candidiasis is associated with 30–40% mortality in severely immunocompromised patients. Among the causal agents, Candida albicans is the dominant one. Various animal models have been developed for investigating gene functions in C. albicans. Zebrafish injection models have increasingly been applied in elucidating C. albicans pathogenesis because of the conserved immunity, prolific fecundity of the zebrafish and the low costs of care systems. In this study, we established a simple, noninvasive zebrafish egg bath infection model, defined its optimal conditions, and evaluated the model with various C. albicans mutant strains. The deletion of SAP6 did not have significant effect on the virulence. By contrast, the deletion of BCR1, CPH1, EFG1, or TEC1 significantly reduced the virulence under current conditions. Furthermore, all embryos survived when co-incubated with bcr1/bcr1, cph1/cph1 efg1/efg1, efg1/efg1, or tec1/tec1 mutant cells. The results indicated that our novel zebrafish model is time-saving and cost effective. PMID:26569623

  9. Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish

    EPA Science Inventory

    Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish Tamara Tal, Integrated Systems Toxicology Division, U.S. EPA Background: There are tens of thousands of chemicals that have yet to be fully evaluated for their toxicity by validated in vivo testing ...

  10. Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish

    EPA Science Inventory

    Developing an Experimental Model of Vascular Toxicity in Embryonic Zebrafish Tamara Tal, Integrated Systems Toxicology Division, U.S. EPA Background: There are tens of thousands of chemicals that have yet to be fully evaluated for their toxicity by validated in vivo testing ...

  11. Zebrafish Model for Functional Screening of Flow-Responsive Genes

    PubMed Central

    Serbanovic-Canic, Jovana; de Luca, Amalia; Warboys, Christina; Ferreira, Pedro F.; Luong, Le A.; Hsiao, Sarah; Gauci, Ismael; Mahmoud, Marwa; Feng, Shuang; Souilhol, Celine; Bowden, Neil; Ashton, John-Paul; Walczak, Henning; Firmin, David; Krams, Rob; Mason, Justin C.; Haskard, Dorian O.; Sherwin, Spencer; Ridger, Victoria; Chico, Timothy J.A.

    2017-01-01

    Objective— Atherosclerosis is initiated at branches and bends of arteries exposed to disturbed blood flow that generates low shear stress. This mechanical environment promotes lesions by inducing endothelial cell (EC) apoptosis and dysfunction via mechanisms that are incompletely understood. Although transcriptome-based studies have identified multiple shear-responsive genes, most of them have an unknown function. To address this, we investigated whether zebrafish embryos can be used for functional screening of mechanosensitive genes that regulate EC apoptosis in mammalian arteries. Approach and Results— First, we demonstrated that flow regulates EC apoptosis in developing zebrafish vasculature. Specifically, suppression of blood flow in zebrafish embryos (by targeting cardiac troponin) enhanced that rate of EC apoptosis (≈10%) compared with controls exposed to flow (≈1%). A panel of candidate regulators of apoptosis were identified by transcriptome profiling of ECs from high and low shear stress regions of the porcine aorta. Genes that displayed the greatest differential expression and possessed 1 to 2 zebrafish orthologues were screened for the regulation of apoptosis in zebrafish vasculature exposed to flow or no-flow conditions using a knockdown approach. A phenotypic change was observed in 4 genes; p53-related protein (PERP) and programmed cell death 2–like protein functioned as positive regulators of apoptosis, whereas angiopoietin-like 4 and cadherin 13 were negative regulators. The regulation of perp, cdh13, angptl4, and pdcd2l by shear stress and the effects of perp and cdh13 on EC apoptosis were confirmed by studies of cultured EC exposed to flow. Conclusions— We conclude that a zebrafish model of flow manipulation coupled to gene knockdown can be used for functional screening of mechanosensitive genes in vascular ECs, thus providing potential therapeutic targets to prevent or treat endothelial injury at atheroprone sites. PMID:27834691

  12. Zebrafish as a disease model for studying human hepatocellular carcinoma

    PubMed Central

    Lu, Jeng-Wei; Ho, Yi-Jung; Yang, Yi-Ju; Liao, Heng-An; Ciou, Shih-Ci; Lin, Liang-In; Ou, Da-Liang

    2015-01-01

    Liver cancer is one of the world’s most common cancers and the second leading cause of cancer deaths. Hepatocellular carcinoma (HCC), a primary hepatic cancer, accounts for 90%-95% of liver cancer cases. The pathogenesis of HCC consists of a stepwise process of liver damage that extends over decades, due to hepatitis, fatty liver, fibrosis, and cirrhosis before developing fully into HCC. Multiple risk factors are highly correlated with HCC, including infection with the hepatitis B or C viruses, alcohol abuse, aflatoxin exposure, and metabolic diseases. Over the last decade, genetic alterations, which include the regulation of multiple oncogenes or tumor suppressor genes and the activation of tumorigenesis-related pathways, have also been identified as important factors in HCC. Recently, zebrafish have become an important living vertebrate model organism, especially for translational medical research. In studies focusing on the biology of cancer, carcinogen induced tumors in zebrafish were found to have many similarities to human tumors. Several zebrafish models have therefore been developed to provide insight into the pathogenesis of liver cancer and the related drug discovery and toxicology, and to enable the evaluation of novel small-molecule inhibitors. This review will focus on illustrative examples involving the application of zebrafish models to the study of human liver disease and HCC, through transgenesis, genome editing technology, xenografts, drug discovery, and drug-induced toxic liver injury. PMID:26576090

  13. Zebrafish models of human eye and inner ear diseases.

    PubMed

    Blanco-Sánchez, B; Clément, A; Phillips, J B; Westerfield, M

    2017-01-01

    Eye and inner ear diseases are the most common sensory impairments that greatly impact quality of life. Zebrafish have been intensively employed to understand the fundamental mechanisms underlying eye and inner ear development. The zebrafish visual and vestibulo-acoustic systems are very similar to these in humans, and although not yet mature, they are functional by 5days post-fertilization (dpf). In this chapter, we show how the zebrafish has significantly contributed to the field of biomedical research and how researchers, by establishing disease models and meticulously characterizing their phenotypes, have taken the first steps toward therapies. We review here models for (1) eye diseases, (2) ear diseases, and (3) syndromes affecting eye and/or ear. The use of new genome editing technologies and high-throughput screening systems should increase considerably the speed at which knowledge from zebrafish disease models is acquired, opening avenues for better diagnostics, treatments, and therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. A new model to study visual attention in zebrafish.

    PubMed

    Braida, Daniela; Ponzoni, Luisa; Martucci, Roberta; Sala, Mariaelvina

    2014-12-03

    The major part of cognitive tasks applied to zebrafish has not fully assessed their attentional ability, a process by which the nervous system learns, organizes sensory input and generates coordinated behaviour. In an attempt to maximize the value of zebrafish as an animal model of cognition, we tested the possibility to apply a modified version of novel object recognition test named virtual object recognition test (VORT) using 2D geometrical shapes (square, triangle, circle, cross, etc.) on two iPod 3.5-inch widescreen displays, located on two opposite walls of the water tank. Each fish was subjected to a familiarization trial (T1), and after different time delays (from 5 min to 96 h) to a novel shape recognition trial (T2). A progressive decrease, across time, of memory performance, in terms of mean discrimination index and mean exploration time, was shown. The predictive validity was tested using cholinergic drugs. Nicotine (0.02 mg/kg intraperitoneally, IP) significantly increased, while scopolamine (0.025 mg/kg IP) and mecamylamine decreased, mean discrimination index. Zebrafish discriminated different movements (vertical, horizontal, oblique) and the discrimination index increased significantly when moving poorly discriminated shapes were presented, thus increasing visual attention. Taken together these findings demonstrate that VORT is a viable, fast and useful model to evaluate sustained attention in zebrafish and for predicting the efficacy of pharmacotherapies for cognitive disorders.

  15. ZEBRAFISH AS AN IN VIVO MODEL FOR SUSTAINABLE CHEMICAL DESIGN.

    PubMed

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

    2016-12-21

    Heightened public awareness about the many thousands of chemicals in use and present as persistent contaminants in the environment has increased the demand for safer chemicals and more rigorous toxicity testing. There is a growing recognition that the use of traditional test models and empirical approaches is impractical for screening for toxicity the many thousands of chemicals in the environment and the hundreds of new chemistries introduced each year. These realities coupled with the green chemistry movement have prompted efforts to implement more predictive-based approaches to evaluate chemical toxicity early in product development. While used for many years in environmental toxicology and biomedicine, zebrafish use has accelerated more recently in genetic toxicology, high throughput screening (HTS), and behavioral testing. This review describes major advances in these testing methods that have positioned the zebrafish as a highly applicable model in chemical safety evaluations and sustainable chemistry efforts. Many toxic responses have been shown to be shared among fish and mammals owing to their generally well-conserved development, cellular networks, and organ systems. These shared responses have been observed for chemicals that impair endocrine functioning, development, and reproduction, as well as those that elicit cardiotoxicity and carcinogenicity, among other diseases. HTS technologies with zebrafish enable screening large chemical libraries for bioactivity that provide opportunities for testing early in product development. A compelling attribute of the zebrafish centers on being able to characterize toxicity mechanisms across multiple levels of biological organization from the genome to receptor interactions and cellular processes leading to phenotypic changes such as developmental malformations. Finally, there is a growing recognition of the links between human and wildlife health and the need for approaches that allow for assessment of real world

  16. Zebrafish as animal model for aquaculture nutrition research

    PubMed Central

    Ulloa, Pilar E.; Medrano, Juan F.; Feijoo, Carmen G.

    2014-01-01

    The aquaculture industry continues to promote the diversification of ingredients used in aquafeed in order to achieve a more sustainable aquaculture production system. The evaluation of large numbers of diets in aquaculture species is costly and requires time-consuming trials in some species. In contrast, zebrafish (Danio rerio) can solve these drawbacks as an experimental model, and represents an ideal organism to carry out preliminary evaluation of diets. In addition, zebrafish has a sequenced genome allowing the efficient utilization of new technologies, such as RNA-sequencing and genotyping platforms to study the molecular mechanisms that underlie the organism’s response to nutrients. Also, biotechnological tools like transgenic lines with fluorescently labeled neutrophils that allow the evaluation of the immune response in vivo, are readily available in this species. Thus, zebrafish provides an attractive platform for testing many ingredients to select those with the highest potential of success in aquaculture. In this perspective article aspects related to diet evaluation in which zebrafish can make important contributions to nutritional genomics and nutritional immunity are discussed. PMID:25309575

  17. An Individual-Based Model of Zebrafish Population Dynamics Accounting for Energy Dynamics

    PubMed Central

    Beaudouin, Rémy; Goussen, Benoit; Piccini, Benjamin; Augustine, Starrlight; Devillers, James; Brion, François; Péry, Alexandre R. R.

    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) was coupled to an individual based model of zebrafish population dynamics (IBM model). Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can already serve to predict the impact of compounds at the population level. PMID:25938409

  18. The Developing Utility of Zebrafish Models for Cognitive Enhancers Research

    PubMed Central

    Stewart, Adam Michael; Kalueff, Allan V

    2012-01-01

    Whereas cognitive impairment is a common symptom in multiple brain disorders, predictive and high-throughput animal models of cognition and behavior are becoming increasingly important in the field of translational neuroscience research. In particular, reliable models of the cognitive deficits characteristic of numerous neurobehavioral disorders such as Alzheimer’s disease and schizophrenia have become a significant focus of investigation. While rodents have traditionally been used to study cognitive phenotypes, zebrafish (Danio rerio) are gaining popularity as an excellent model to complement current translational neuroscience research. Here we discuss recent advances in pharmacological and genetic approaches using zebrafish models to study cognitive impairments and to discover novel cognitive enhancers and neuroprotective mechanisms. PMID:23449968

  19. Zebrafish as a novel experimental model for developmental toxicology.

    PubMed

    Teraoka, Hiroki; Dong, Wu; Hiraga, Takeo

    2003-06-01

    It is widely believed that embryos and infants during development are highly sensitive to chemicals that cause serious damage to growth. However, knowledge on the mechanisms of developmental toxicity is scarce. One reason for this is limited convenient model system other than organ cultures using rodents to study the various aspects of developmental toxicology. Cultured cells are not always adequate for this purpose, since events in morphogenesis are processed through interactions with other tissues. We focused on zebrafish embryo (Danio rerio), one of the most important organisms in developmental biology. Saturation mutagenesis, applied to drosophila and nematode to define the functions of genes, has been carried out in zebrafish but almost no other vertebrate, and several thousand lines are available due to the rapid growth and transparent body of this embryo. Enhanced databases for the genome and ESTs are available at websites with abundant genetic and biological background. By targeted gene knock-down with morpholino-modified antisense oligonucleotieds (morpholinos), the translation of a specific protein can be transiently blocked for several days. Many reporter systems in vivo have been established mainly as GFP-transgenic fish for environmental chemicals. Although several excellent studies have been performed with zebrafish embryos on the effects of chemicals, the developmental toxicology of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been most extensively studied to date. We have found that TCDD induces apoptosis in dorsal midbrain with a concomitant decrease in local blood flow, using developing zebrafish. TCDD seems to produce oxidative stress through CYP1A induction in vascular endothelium, resulting in local circulation failure and apoptosis in the dorsal midbrain. In addition to applications in toxicology, an experimental system with zebrafish embryos could help to clarify the mechanism of congenital anomaly, which arises from genetic mutation.

  20. Germ cell mutagenesis in medaka fish after exposures to high-energy cosmic ray nuclei: A human model

    PubMed Central

    Shimada, Atsuko; Shima, Akihiro; Nojima, Kumie; Seino, Yo; Setlow, Richard B.

    2005-01-01

    Astronauts beyond the Earth's orbit are exposed to high-energy cosmic-ray nuclei with high values of linear energy transfer (LET), resulting in much more biological damage than from x-rays or γ-rays and may result in mutations and cancer induction. The relative biological effectiveness of these nuclei depends on the LET, rising to as high as ≈50 at LET values of ≈100-200 keV/μm. An endpoint of concern is germ cell mutations passed on to offspring, arising from exposure to these nuclei. A vertebrate model for germ cell mutation is Medaka fish (Oryzias latipes). We exposed wild type males to doses of 1 GeV per nucleon Fe nuclei or to 290 MeV per nucleon C nuclei. They were mated to females with recessive mutations at five-color loci. The transparent embryos from >100 days of mating (representing exposed sperm, spermatids, or spermatogonia) were observed so as to detect dominant lethal mutations and total color mutations, even though the embryos might not hatch. The relative number of mutant embryos as a function of dose were compared with those induced by γ-rays. The relative biological effectiveness values for dominant lethal mutations and total color mutations for exposed sperm and spermatids were 1.3-2.1 for exposure to C nuclei and 1.5-3.0 for exposure to Fe nuclei. (The spermatogonial data were uncertain.) These low values, and the negligible number of viable mutations, compared with those for mutations in somatic cells and for neoplastic transformation, indicate that germ cell mutations arising from exposures to cosmic ray nuclei are not a significant hazard to astronauts. PMID:15829584

  1. Germ cell mutagenesis in medaka fish after exposures to high-energy cosmic ray nuclei: A human model.

    PubMed

    Shimada, Atsuko; Shima, Akihiro; Nojima, Kumie; Seino, Yo; Setlow, Richard B

    2005-04-26

    Astronauts beyond the Earth's orbit are exposed to high-energy cosmic-ray nuclei with high values of linear energy transfer (LET), resulting in much more biological damage than from x-rays or gamma-rays and may result in mutations and cancer induction. The relative biological effectiveness of these nuclei depends on the LET, rising to as high as approximately 50 at LET values of approximately 100-200 keV/microm. An endpoint of concern is germ cell mutations passed on to offspring, arising from exposure to these nuclei. A vertebrate model for germ cell mutation is Medaka fish (Oryzias latipes). We exposed wild type males to doses of 1 GeV per nucleon Fe nuclei or to 290 MeV per nucleon C nuclei. They were mated to females with recessive mutations at five-color loci. The transparent embryos from >100 days of mating (representing exposed sperm, spermatids, or spermatogonia) were observed so as to detect dominant lethal mutations and total color mutations, even though the embryos might not hatch. The relative number of mutant embryos as a function of dose were compared with those induced by gamma-rays. The relative biological effectiveness values for dominant lethal mutations and total color mutations for exposed sperm and spermatids were 1.3-2.1 for exposure to C nuclei and 1.5-3.0 for exposure to Fe nuclei. (The spermatogonial data were uncertain.) These low values, and the negligible number of viable mutations, compared with those for mutations in somatic cells and for neoplastic transformation, indicate that germ cell mutations arising from exposures to cosmic ray nuclei are not a significant hazard to astronauts.

  2. Germ cell mutagenesis in medaka fish after exposures to high-energy cosmic ray nuclei: A human model

    NASA Astrophysics Data System (ADS)

    Shimada, Atsuko; Shima, Akihiro; Nojima, Kumie; Seino, Yo; Setlow, Richard B.

    2005-04-01

    Astronauts beyond the Earth's orbit are exposed to high-energy cosmic-ray nuclei with high values of linear energy transfer (LET), resulting in much more biological damage than from x-rays or -rays and may result in mutations and cancer induction. The relative biological effectiveness of these nuclei depends on the LET, rising to as high as 50 at LET values of 100-200 keV/µm. An endpoint of concern is germ cell mutations passed on to offspring, arising from exposure to these nuclei. A vertebrate model for germ cell mutation is Medaka fish (Oryzias latipes). We exposed wild type males to doses of 1 GeV per nucleon Fe nuclei or to 290 MeV per nucleon C nuclei. They were mated to females with recessive mutations at five-color loci. The transparent embryos from >100 days of mating (representing exposed sperm, spermatids, or spermatogonia) were observed so as to detect dominant lethal mutations and total color mutations, even though the embryos might not hatch. The relative number of mutant embryos as a function of dose were compared with those induced by -rays. The relative biological effectiveness values for dominant lethal mutations and total color mutations for exposed sperm and spermatids were 1.3-2.1 for exposure to C nuclei and 1.5-3.0 for exposure to Fe nuclei. (The spermatogonial data were uncertain.) These low values, and the negligible number of viable mutations, compared with those for mutations in somatic cells and for neoplastic transformation, indicate that germ cell mutations arising from exposures to cosmic ray nuclei are not a significant hazard to astronauts. astronaut hazards | linear energy transfer | relative biological effect

  3. Histopathology of a wavy medaka

    PubMed Central

    Irie, Kota; Kuroda, Yusuke; Mimori, Norihiko; Hayashi, Seigo; Abe, Masayoshi; Tsuji, Naho; Sugiyama, Akihiko; Furukawa, Satoshi

    2016-01-01

    Wavy medakas are medakas that exhibit spinal curvature characterized by dorsoventrally curved vertebrae. We found a spontaneous wavy medaka in our experimental stock and subjected it to a histopathological examination. Macroscopically, the wavy medaka’s spine formed an M shape, and its vertebrae displayed a dorsoventral curvature that started at the third vertebral bone. Microscopically, the vertebral cavities were filled with fibrous tissue, which was similar to that seen in the central parts of the intervertebral discs of a normal medaka. The vertebral joints were composed of vacuolated notochord cells without intervertebral disc formation. These changes were also observed in the caudal region, which exhibited less curvature. In the normal medaka, the intervertebral discs form via the regression of the notochord that plays a key role in the development of vertebrae and disc formation. We concluded that notochordal subinvolution had induced intervertebral disc dysplasia, leading to lordokyphosis, in the wavy medaka. PMID:27182116

  4. Data-driven stochastic modelling of zebrafish locomotion.

    PubMed

    Zienkiewicz, Adam; Barton, David A W; Porfiri, Maurizio; di Bernardo, Mario

    2015-11-01

    In this work, we develop a data-driven modelling framework to reproduce the locomotion of fish in a confined environment. Specifically, we highlight the primary characteristics of the motion of individual zebrafish (Danio rerio), and study how these can be suitably encapsulated within a mathematical framework utilising a limited number of calibrated model parameters. Using data captured from individual zebrafish via automated visual tracking, we develop a model using stochastic differential equations and describe fish as a self propelled particle moving in a plane. Based on recent experimental evidence of the importance of speed regulation in social behaviour, we extend stochastic models of fish locomotion by introducing experimentally-derived processes describing dynamic speed regulation. Salient metrics are defined which are then used to calibrate key parameters of coupled stochastic differential equations, describing both speed and angular speed of swimming fish. The effects of external constraints are also included, based on experimentally observed responses. Understanding the spontaneous dynamics of zebrafish using a bottom-up, purely data-driven approach is expected to yield a modelling framework for quantitative investigation of individual behaviour in the presence of various external constraints or biological assays.

  5. Learning from small fry: the zebrafish as a genetic model organism for aquaculture fish species.

    PubMed

    Dahm, Ralf; Geisler, Robert

    2006-01-01

    In recent years, the zebrafish has become one of the most prominent vertebrate model organisms used to study the genetics underlying development, normal body function, and disease. The growing interest in zebrafish research was paralleled by an increase in tools and methods available to study zebrafish. While zebrafish research initially centered on mutagenesis screens (forward genetics), recent years saw the establishment of reverse genetic methods (morpholino knock-down, TILLING). In addition, increasingly sophisticated protocols for generating transgenic zebrafish have been developed and microarrays are now available to characterize gene expression on a near genome-wide scale. The identification of loci underlying specific traits is aided by genetic, physical, and radiation hybrid maps of the zebrafish genome and the zebrafish genome project. As genomic resources for aquacultural species are increasingly being generated, a meaningful interaction between zebrafish and aquacultural research now appears to be possible and beneficial for both sides. In particular, research on nutrition and growth, stress, and disease resistance in the zebrafish can be expected to produce results applicable to aquacultural fish, for example, by improving husbandry and formulated feeds. Forward and reverse genetics approaches in the zebrafish, together with the known conservation of synteny between the species, offer the potential to identify and verify candidate genes for quantitative trait loci (QTLs) to be used in marker-assisted breeding. Moreover, some technologies from the zebrafish field such as TILLING may be directly transferable to aquacultural research and production.

  6. Generation of Transparent Zebrafish with Fluorescent Ovaries: A Living Visible Model for Reproductive Biology.

    PubMed

    Akhter, Afroza; Kumagai, Ryo-Ichi; Roy, Shimi Rani; Ii, Sanae; Tokumoto, Mika; Hossain, Babul; Wang, Jun; Klangnurak, Wanlada; Miyazaki, Takehiro; Tokumoto, Toshinobu

    2016-06-01

    The transparent zebrafish enables researchers to study the morphology and distribution of cells and tissues in vivo. To capture the dynamic processes of germ cell proliferation and juvenile ovarian development in zebrafish in vivo, we established transgenic (TG) lines to allow us to monitor the changes in the ovaries of living fish. The original transgenic line with ovarian fluorescence was occasionally established. Although the cDNA integrated in the strain was constructed for the expression of enhanced green fluorescent protein (EGFP) driven by the medaka β-actin promoter, expression of EGFP is restricted to the oocytes and gills in adult fish. Mutant strains with transparent bodies, roy and ruby, were isolated in zebrafish. In this study, we crossed the TG strain with fluorescent ovary with transparent strains and established the TG (β-actin:EGFP);ruby strain. The strain is highly transparent, and the oocytes are easily observed in living fish. We identified a fluorescent tissue that might contain the undifferentiated germ cells close to the cloaca in the strain. This strain can be used for analysis of ovarian development in vivo.

  7. Analysis of the retina in the zebrafish model.

    PubMed

    Malicki, J; Pooranachandran, N; Nikolaev, A; Fang, X; Avanesov, A

    2016-01-01

    The vertebrate retina is remarkably conserved in evolution. Its relative simplicity and well-defined architecture make it particularly suitable for developmental and functional analysis of neuronal networks in the vertebrate central nervous system. The zebrafish model is at the forefront of these studies. It makes it possible to apply a wide variety of parallel embryological, genetic, and imaging tools to study the eye. Here we discuss experimental approaches that range from cell lineage analysis to the imaging of synaptic calcium currents and atomic force microscopy. These methods are currently used in zebrafish to model morphogenetic events during early development of the eye primordium, cell fate decisions during retinal neurogenesis, and the differentiation and function of the many fine structural features that underlie the detection and processing of light stimuli in the eye.

  8. Zebrafish: an in vivo model for nano EHS studies.

    PubMed

    Lin, Sijie; Zhao, Yan; Nel, André E; Lin, Shuo

    2013-05-27

    To assure a responsible and sustainable growth of nanotechnology, the environmental health and safety (EHS) aspect of engineered nanomaterials and nano-related products needs to be addressed at a rate commensurate with the expansion of nanotechnology. Zebrafish has been demonstrated as a correlative in vivo vertebrate model for such task, and the current advances of using zebrafish for nano EHS studies are summarized here. In addition to morphological and histopathological observations, the accessibility of gene manipulation would greatly empower such a model for detailed mechanistic studies of any nanoparticles of interest. The potential for establishing high-throughput screening platforms to facilitate the nano EHS studies is highlighted, and a discussion is presented on how toxicogenomics approaches represent a future direction to guide the identification of toxicity pathways. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Zebrafish: an in vivo model for nano EHS studies

    PubMed Central

    Zhao, Yan; Nel, André E.; Lin, Shuo

    2014-01-01

    To assure a responsible and sustainable growth of nanotechnology, the environmental health and safety (EHS) aspect of engineered nanomaterials and nano-related products needs to be addressed at a rate commensurate with the expansion of nanotechnology. Zebrafish has been demonstrated as a correlative in vivo vertebrate model for such task, and the current advances of using zebrafish for nano EHS studies are summarized here. In addition to morphological and histopathological observations, the accessibility of gene manipulation would greatly empower such a model for detailed mechanistic studies of any nanoparticles of interest. The potential for establishing high-throughput screening platforms to facilitate the nano EHS studies is highlighted, and a discussion is presented on how toxicogenomics approaches represent a future direction to guide the identification of toxicity pathways. PMID:23208995

  10. Zebrafish Models of BCR-ABL-Induced Leukemogenesis

    DTIC Science & Technology

    2005-10-01

    ORGANIZATION: Dana-Farber Cancer Institute Boston, MA 02115 REPORT DATE: October 2005 TYPE OF REPORT: Final PREPARED FOR: U.S. Army Medical Research...NUMBER Sf. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Dana-Farber Cancer Institute...stable transgenic zebrafish models for BCR-ABL induced leukemia will establish the necessary groundwork that will be valuable in conducting future

  11. Zebrafish as a Novel Vertebrate Model To Dissect Enterococcal Pathogenesis

    PubMed Central

    Renshaw, Stephen A.; Ogryzko, Nikolay V.; Foster, Simon J.; Serror, Pascale

    2013-01-01

    Enterococcus faecalis is an opportunistic pathogen responsible for a wide range of life-threatening nosocomial infections, such as septicemia, peritonitis, and endocarditis. E. faecalis infections are associated with a high mortality and substantial health care costs and cause therapeutic problems due to the intrinsic resistance of this bacterium to antibiotics. Several factors contributing to E. faecalis virulence have been identified. Due to the variety of infections caused by this organism, numerous animal models have been used to mimic E. faecalis infections, but none of them is considered ideal for monitoring pathogenesis. Here, we studied for the first time E. faecalis pathogenesis in zebrafish larvae. Using model strains, chosen isogenic mutants, and fluorescent derivatives expressing green fluorescent protein (GFP), we analyzed both lethality and bacterial dissemination in infected larvae. Genetically engineered immunocompromised zebrafish allowed the identification of two critical steps for successful establishment of disease: (i) host phagocytosis evasion mediated by the Epa rhamnopolysaccharide and (ii) tissue damage mediated by the quorum-sensing Fsr regulon. Our results reveal that the zebrafish is a novel, powerful model for studying E. faecalis pathogenesis, enabling us to dissect the mechanism of enterococcal virulence. PMID:24002065

  12. Computational Graph Theoretical Model of the Zebrafish Sensorimotor Pathway

    NASA Astrophysics Data System (ADS)

    Peterson, Joshua M.; Stobb, Michael; Mazzag, Bori; Gahtan, Ethan

    2011-11-01

    Mapping the detailed connectivity patterns of neural circuits is a central goal of neuroscience and has been the focus of extensive current research [4, 3]. The best quantitative approach to analyze the acquired data is still unclear but graph theory has been used with success [3, 1]. We present a graph theoretical model with vertices and edges representing neurons and synaptic connections, respectively. Our system is the zebrafish posterior lateral line sensorimotor pathway. The goal of our analysis is to elucidate mechanisms of information processing in this neural pathway by comparing the mathematical properties of its graph to those of other, previously described graphs. We create a zebrafish model based on currently known anatomical data. The degree distributions and small-world measures of this model is compared to small-world, random and 3-compartment random graphs of the same size (with over 2500 nodes and 160,000 connections). We find that the zebrafish graph shows small-worldness similar to other neural networks and does not have a scale-free distribution of connections.

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

    PubMed

    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.

  14. Zebrafish models of human motor neuron diseases: advantages and limitations.

    PubMed

    Babin, Patrick J; Goizet, Cyril; Raldúa, Demetrio

    2014-07-01

    Motor neuron diseases (MNDs) are an etiologically heterogeneous group of disorders of neurodegenerative origin, which result in degeneration of lower (LMNs) and/or upper motor neurons (UMNs). Neurodegenerative MNDs include pure hereditary spastic paraplegia (HSP), which involves specific degeneration of UMNs, leading to progressive spasticity of the lower limbs. In contrast, spinal muscular atrophy (SMA) involves the specific degeneration of LMNs, with symmetrical muscle weakness and atrophy. Amyotrophic lateral sclerosis (ALS), the most common adult-onset MND, is characterized by the degeneration of both UMNs and LMNs, leading to progressive muscle weakness, atrophy, and spasticity. A review of the comparative neuroanatomy of the human and zebrafish motor systems showed that, while the zebrafish was a homologous model for LMN disorders, such as SMA, it was only partially relevant in the case of UMN disorders, due to the absence of corticospinal and rubrospinal tracts in its central nervous system. Even considering the limitation of this model to fully reproduce the human UMN disorders, zebrafish offer an excellent alternative vertebrate model for the molecular and genetic dissection of MND mechanisms. Its advantages include the conservation of genome and physiological processes and applicable in vivo tools, including easy imaging, loss or gain of function methods, behavioral tests to examine changes in motor activity, and the ease of simultaneous chemical/drug testing on large numbers of animals. This facilitates the assessment of the environmental origin of MNDs, alone or in combination with genetic traits and putative modifier genes. Positive hits obtained by phenotype-based small-molecule screening using zebrafish may potentially be effective drugs for treatment of human MNDs.

  15. Quantifying Vibrio cholerae enterotoxicity in a zebrafish infection model.

    PubMed

    Mitchell, Kristie C; Breen, Paul; Britton, Sarah; Neely, Melody N; Withey, Jeffrey H

    2017-06-16

    Vibrio cholerae is the etiological agent of cholera, an acute intestinal infection in humans characterized by voluminous watery diarrhea. Cholera is spread through ingestion of contaminated food or water, primarily in developing countries that lack the proper infrastructure for proper water and sewage treatment. Vibrio cholerae is an aquatic bacterium that inhabits coastal and estuarine areas, and is known to have several environmental reservoirs, including fish. Our laboratory has recently described the use of the zebrafish as a new animal model for the study of V. cholerae intestinal colonization, pathogenesis, and transmission.As early as six hours after exposure to V. cholerae, zebrafish develop diarrhea. Prior work in our laboratory has shown that this is not due to the action of cholera toxin. We hypothesize that accessory toxins produced by V. cholerae are the cause of diarrhea in infected zebrafish. In order to assess the effects of accessory toxins in the zebrafish, it was necessary to develop a method of quantifying diarrheal volume as a measure of pathogenesis. Here, we have adapted cell density, protein, and mucin assays, along with enumeration of V. cholerae in the zebrafish intestinal tract and in the infection water, to achieve this goal. Combined, these assays should help us determine which toxins have the greatest diarrheagenic effect in fish, and consequently, which toxins may play a role in environmental transmission.Importance Identification of the accessory toxins that cause diarrhea in zebrafish can help us understand more about the role of fish in the wild as aquatic reservoirs for V. cholerae It is plausible that accessory toxins can act to prolong colonization and subsequent shedding of V. cholerae back into the environment, thus perpetuating and facilitating transmission during an outbreak. It is also possible that accessory toxins help to maintain low levels of intestinal colonization in fish, giving V. cholerae an advantage when

  16. Zebrafish as a model for zoonotic aquatic pathogens

    PubMed Central

    Rowe, Hannah M.; Withey, Jeffrey H.; Neely, Melody N.

    2014-01-01

    Aquatic habitats harbor a multitude of bacterial species. Many of these bacteria can act as pathogens to aquatic species and/or non-aquatic organisms, including humans, that come into contact with contaminated water sources or colonized aquatic organisms. In many instances, the bacteria are not pathogenic to the aquatic species they colonize and are only considered pathogens when they come into contact with humans. There is a general lack of knowledge about how the environmental lifestyle of these pathogens allows them to persist, replicate and produce the necessary pathogenic mechanisms to successfully transmit to the human host and cause disease. Recently, the zebrafish infectious disease model has emerged as an ideal system for examining aquatic pathogens, both in the aquatic environment and during infection of the human host. This review will focus on how the zebrafish has been used successfully to analyze the pathogenesis of aquatic bacterial pathogens. PMID:24607289

  17. Zebrafish: predictive model for targeted cancer therapeutics from nature.

    PubMed

    Zulkhernain, Nursafwana Syazwani; Teo, Soo Hwang; Patel, Vyomesh; Tan, Pei Jean

    2014-01-01

    Targeted therapy, the treatment of cancer based on an underlying genetic alteration, is rapidly gaining favor as the preferred therapeutic approach. To date, although natural products represent a rich resource of bio-diverse drug candidates, only a few have been identified to be effective as targeted cancer therapies largely due to the incompatibilities to current high-throughput screening methods. In this article, we review the utility of a zebrafish developmental screen for bioactive natural product-based compounds that target signaling pathways that are intimately shared with those in humans. Any bioactive compound perturbing signaling pathways identified from phenotypic developmental defects in zebrafish embryos provide an opportunity for developing targeted therapies for human cancers. This model provides a promising tool in the search for targeted cancer therapeutics from natural products.

  18. Toxicity of silver nanoparticles in zebrafish models.

    PubMed

    Asharani, P V; Lian Wu, Yi; Gong, Zhiyuan; Valiyaveettil, Suresh

    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(+) 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.

  19. Toxicity of silver nanoparticles in zebrafish models

    NASA Astrophysics Data System (ADS)

    Asharani, P. V.; Lian Wu, Yi; Gong, Zhiyuan; Valiyaveettil, Suresh

    2008-06-01

    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.

  20. Zebrafish as a systems toxicology model for developmental neurotoxicity testing.

    PubMed

    Nishimura, Yuhei; Murakami, Soichiro; Ashikawa, Yoshifumi; Sasagawa, Shota; Umemoto, Noriko; Shimada, Yasuhito; Tanaka, Toshio

    2015-02-01

    The developing brain is extremely sensitive to many chemicals. Exposure to neurotoxicants during development has been implicated in various neuropsychiatric and neurological disorders, including autism spectrum disorder, attention deficit hyperactive disorder, schizophrenia, Parkinson's disease, and Alzheimer's disease. Although rodents have been widely used for developmental neurotoxicity testing, experiments using large numbers of rodents are time-consuming, expensive, and raise ethical concerns. Using alternative non-mammalian animal models may relieve some of these pressures by allowing testing of large numbers of subjects while reducing expenses and minimizing the use of mammalian subjects. In this review, we discuss some of the advantages of using zebrafish in developmental neurotoxicity testing, focusing on central nervous system development, neurobehavior, toxicokinetics, and toxicodynamics in this species. We also describe some important examples of developmental neurotoxicity testing using zebrafish combined with gene expression profiling, neuroimaging, or neurobehavioral assessment. Zebrafish may be a systems toxicology model that has the potential to reveal the pathways of developmental neurotoxicity and to provide a sound basis for human risk assessments. © 2014 Japanese Teratology Society.

  1. Zebrafish as an animal model to study ion homeostasis.

    PubMed

    Hwang, Pung-Pung; Chou, Ming-Yi

    2013-09-01

    Zebrafish (Danio rerio) possesses several advantages as an experimental organism, including the applicability of molecular tools, ease of in vivo cellular observation and functional analysis, and rapid embryonic development, making it an emerging model for the study of integrative and regulatory physiology and, in particular, the epithelial transport associated with body fluid ionic homeostasis. Zebrafish inhabits a hypotonic freshwater environment, and as such, the gills (or the skin, during embryonic stages) assume the role of the kidney in body fluid ionic homeostasis. Four types of ionocyte expressing distinct sets of transporters have been identified in these organs: H(+)-ATPase-rich, Na(+)-K(+)-ATPase-rich, Na(+)-Cl(-) cotransporter-expressing and K(+)-secreting cells; these ionocytes perform transepithelial H(+) secretion/Na(+) uptake/NH4 (+) excretion, Ca(2+) uptake, Na(+)/Cl(-) uptake, and K(+) secretion, respectively. Zebrafish ionocytes are analogous to various renal tubular cells, in terms of ion transporter expression and function. During embryonic development, ionocyte progenitors develop from epidermal stem cells and then differentiate into different types of ionocyte through a positive regulatory loop of Foxi3a/-3b and other transcription factors. Several hormones, including cortisol, vitamin D, stanniocalcin-1, calcitonin, and isotocin, were found to participate in the control pathways of ionic homeostasis by precisely studying the target ion transport pathways, ion transporters, or ionocytes of the hormonal actions. In conclusion, the zebrafish model not only enhances our understanding of body fluid ion homeostasis and hormonal control in fish but also informs studies on mammals and other animal species, thereby providing new insights into related fields.

  2. Comparative analysis of her genes during fish somitogenesis suggests a mouse/chick-like mode of oscillation in medaka.

    PubMed

    Gajewski, Martin; Elmasri, Harun; Girschick, Manuel; Sieger, Dirk; Winkler, Christoph

    2006-06-01

    Somitogenesis is the key developmental step, which divides the vertebrate body axis into segmentally repeated structures. It requires an intricate process of pre-patterning, which is driven by an oscillator mechanism consisting of the Delta-Notch pathway and various hairy- and Enhancer of split-related (her) genes. The subset of her genes, which are necessary to set up the segmentation clock, reveal a complex scenario of interactions. To understand which her genes are essential core players in this process, we compared the expression patterns of somitogenesis-relevant her genes in zebrafish and medaka (Oryzias latipes). Most of the respective medaka genes (Ol-her) are duplicated like what has been shown for zebrafish (Dr-her) and pufferfish genes (Fr-her). However, zebrafish genes show some additional copies and significant differences in expression patterns. For the paralogues Dr-her1 and Dr-her11, only one copy exists in the medaka (Ol-her1/11), which combines the expression patterns found for both zebrafish genes. In contrast to Dr-her5, the medaka orthologue appears to play a role in somitogenesis because it is expressed in the presomitic mesoderm (PSM). PSM expression also suggests a role for both Ol-her13 genes, homologues of mouse Hes6 (mHes6), in this process, which would be consistent with a conserved mHes6 homologue gear in the segmentation clock exclusively in lower vertebrates. Members of the mHes5 homologue group seem to be involved in somite formation in all vertebrates (e.g. Dr- and Ol-her12), although different paralogues are additionally recruited in zebrafish (e.g. Dr-her15) and medaka (e.g. Ol-her4). We found that the linkage between duplicates is strongly conserved between pufferfish and medaka and less well conserved in zebrafish. Nevertheless, linkage and orientation of several her duplicates are identical in all three species. Therefore, small-scale duplications must have happened before whole genome duplication occurred in a fish ancestor

  3. Zebrafish as a natural host model for Vibrio cholerae colonization and transmission.

    PubMed

    Runft, Donna L; Mitchell, Kristie C; Abuaita, Basel H; Allen, Jonathan P; Bajer, Sarah; Ginsburg, Kevin; Neely, Melody N; Withey, Jeffrey H

    2014-03-01

    The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival.

  4. Zebrafish as a Natural Host Model for Vibrio cholerae Colonization and Transmission

    PubMed Central

    Runft, Donna L.; Mitchell, Kristie C.; Abuaita, Basel H.; Allen, Jonathan P.; Bajer, Sarah; Ginsburg, Kevin; Neely, Melody N.

    2014-01-01

    The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival. PMID:24375135

  5. A new high-content model system for studies of gastrointestinal transit: the zebrafish.

    PubMed

    Rich, A

    2009-03-01

    The zebrafish gastrointestinal (GI) tract displays an anatomy and cellular architecture that is similar to the human GI tract, with concentric layers of inner epithelia, connective tissue, circular muscle and outer longitudinal muscle layers. Propulsion of luminal content results from the integrated activity of smooth muscle cells, enteric neurons and the interstitial cells of Cajal (ICC). Zebrafish larvae are transparent and propagating contractions in the entire GI tract are easily visualized. A new moderate-throughput zebrafish-based GI transit assay is described in this issue of Neurogastroenterology and Motility. This assay utilizes intact zebrafish larvae which contain essential regulatory elements (ICC and enteric neurons). Forward genetic analysis, which identifies genes underlying specific phenotypes, is possible using the zebrafish system. The zebrafish model system compliments existing models for studies of GI motility and will contribute to the understanding of the regulation of GI motility, and to identification of novel drug targets.

  6. Genomic editing opens new avenues for zebrafish as a model for neurodegeneration.

    PubMed

    Schmid, Bettina; Haass, Christian

    2013-11-01

    Zebrafish has become a popular model organism to study human diseases. We will highlight the advantages and limitations of zebrafish as a model organism to study neurodegenerative diseases and introduce zinc finger nucleases, transcription activator-like effector nucleases, and the recently established clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated system for genome editing. The efficiency of the novel genome editing tools now greatly facilitates knock-out and, importantly, also makes knock-in approaches feasible in zebrafish. Genome editing in zebrafish avoids unspecific phenotypes caused by off-target effects and toxicity as frequently seen in conventional knock-down approaches.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Establishment of HRASG12V Transgenic Medaka as a Stable Tumor Model for In Vivo Screening of Anticancer Drugs

    PubMed Central

    Matsuzaki, Yuriko; Hosokai, Haru; Mizuguchi, Yukiyo; Fukamachi, Shoji; Shimizu, Atsushi; Saya, Hideyuki

    2013-01-01

    Most targeted anticancer drugs have been identified by screening at the molecular or cellular level in vitro. However, many compounds selected by such costly and time-consuming screening do not prove effective against tumors in vivo. The development of anticancer drugs would thus be facilitated by the availability of an in vivo screening system based on a multicellular organism. We have now established a transgenic line of the freshwater fish medaka in which melanophores (melanocytes) proliferate in a manner dependent on heat shock–induced signaling by a human RAS oncoprotein. The human HRASG12V oncogene was expressed under the control of a melanophore-specific gene promoter in order to allow visualization of tumor growth in live fish maintained in a water tank. The expression of HRASG12V was induced as a result of Cre-mediated recombination by exposure of the fish to a temperature of 37°C for 30 min, given that the Cre gene was placed under the control of a medaka heat shock promoter. One of the stable transgenic lines developed abnormal pigment cell proliferation in the eyes and epidermis with 100% penetrance by 6 months postfertilization. Sorafenib, an inhibitor of RAS signaling, was administered to the transgenic fish and was found both to reduce the extent of melanophore proliferation and to improve survival. The transgenic medaka established here thus represents a promising in vivo system with which to screen potential anticancer drugs that target RAS signaling, and this system can readily be adapted for the screening of agents that target other oncogenes. PMID:23342156

  9. Imaging Cancer Angiogenesis and Metastasis in a Zebrafish Embryo Model.

    PubMed

    Tulotta, C; He, S; van der Ent, W; Chen, L; Groenewoud, A; Spaink, H P; Snaar-Jagalska, B E

    2016-01-01

    Tumor angiogenesis and metastasis are key steps of cancer progression. In vitro and animal model studies have contributed to partially elucidating the mechanisms involved in these processes and in developing therapies. Besides the improvements in fundamental research and the optimization of therapeutic regimes, cancer still remains a major health threatening condition and therefore the development of new models is needed. The zebrafish is a powerful tool to study tumor angiogenesis and metastasis, because it allows the visualization of fluorescently labelled tumor cells inducing vessel remodeling, disseminating and invading surrounding tissues in a whole transparent embryo. The embryo model has also been used to address the contribution of the tumor stroma in sustaining tumor angiogenesis and spreading. Simultaneously, new anti-angiogenic drugs and compounds affecting malignant cell survival and migration can be tested by simply adding the compound into the water of living embryos. Therefore the zebrafish model offers the opportunity to gain more knowledge on cancer angiogenesis and metastasis in vivo with the final aim of providing new translational insights into therapeutic approaches to help patients.

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

    PubMed

    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.

  11. The Genomic and Genetic Toolbox of the Teleost Medaka (Oryzias latipes)

    PubMed Central

    Kirchmaier, Stephan; Naruse, Kiyoshi; Wittbrodt, Joachim; Loosli, Felix

    2015-01-01

    The Japanese medaka, Oryzias latipes, is a vertebrate teleost model with a long history of genetic research. A number of unique features and established resources distinguish medaka from other vertebrate model systems. A large number of laboratory strains from different locations are available. Due to a high tolerance to inbreeding, many highly inbred strains have been established, thus providing a rich resource for genetic studies. Furthermore, closely related species native to different habitats in Southeast Asia permit comparative evolutionary studies. The transparency of embryos, larvae, and juveniles allows a detailed in vivo analysis of development. New tools to study diverse aspects of medaka biology are constantly being generated. Thus, medaka has become an important vertebrate model organism to study development, behavior, and physiology. In this review, we provide a comprehensive overview of established genetic and molecular-genetic tools that render medaka fish a full-fledged vertebrate system. PMID:25855651

  12. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models.

    PubMed

    Mondon, J A; Howitt, J; Tosiano, M; Kwok, K W H; Hinton, D E

    2011-01-01

    Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  13. Toward a Molecular Equivalent Dose: Use of the Medaka Model in Comparative Risk Assessment.

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  14. Toward a Molecular Equivalent Dose: Use of the Medaka Model in Comparative Risk Assessment.

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  15. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  16. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

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

    PubMed

    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.

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

    PubMed

    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. The zebrafish as a model for nociception studies.

    PubMed

    Malafoglia, Valentina; Bryant, Bruce; Raffaeli, William; Giordano, Antonio; Bellipanni, Gianfranco

    2013-10-01

    Nociception is the sensory mechanism used to detect cues that can harm an organism. The understanding of the neural networks and molecular controls of the reception of pain remains an ongoing challenge for biologists. While we have made significant progress in identifying a number of molecules and pathways that are involved in transduction of noxious stimuli, from the skin through the sensory receptor cell and from this to the spinal cord on into the central nervous system, we still lack a clear understanding of the perceptual processes, the responses to pain and the regulation of pain perception. Mice and rat animal models have been extensively used for nociception studies. However, the study of pain and noiception in these organisms can be rather laborious, costly and time consuming. Conversely, the use of Drosophila and Caenorhabditis elegans may be affected by the large evolutionary distance between these animals and humans. We outline here the reasons why zebrafish presents a new and attractive model for studying pain reception and responses and the most interesting findings in the study of nociception that have been obtained using the zebrafish model.

  20. Zebrafish as a Model to Investigate CNS Myelination

    PubMed Central

    Preston, Marnie A.; Macklin, Wendy B.

    2015-01-01

    Myelin plays a critical role in proper neuronal function by providing trophic and metabolic support to axons and facilitating energy-efficient saltatory conduction. Myelination is influenced by numerous molecules including growth factors, hormones, transmembrane receptors and extracellular molecules, which activate signaling cascades that drive cellular maturation. Key signaling molecules and downstream signaling cascades controlling myelination have been identified in cell culture systems. However, in vitro systems are not able to faithfully replicate the complex in vivo signaling environment that occurs during development or following injury. Currently, it remains time-consuming and expensive to investigate myelination in vivo in rodents, the most widely used model for studying mammalian myelination. As such, there is a need for alternative in vivo myelination models, particularly ones that can test molecular mechanisms without removing oligodendrocyte lineage cells from their native signaling environment or disrupting intercellular interactions with other cell types present during myelination. Here, we review the ever-increasing role of zebrafish in studies uncovering novel mechanisms controlling vertebrate myelination. These innovative studies range from observations of the behavior of single cells during in vivo myelination as well as mutagenesis- and pharmacology-based screens in whole animals. Additionally, we discuss recent efforts to develop novel models of demyelination and oligodendrocyte cell death in adult zebrafish for the study of cellular behavior in real time during repair and regeneration of damaged nervous systems. PMID:25263121

  1. A multi-scale model for correlation in B cell VDJ usage of zebrafish

    NASA Astrophysics Data System (ADS)

    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.

  2. Vertebrate development in the environment of space: models, mechanisms, and use of the medaka

    NASA Technical Reports Server (NTRS)

    Wolgemuth, D. J.; Herrada, G.; Kiss, S.; Cannon, T.; Forsstrom, C.; Pranger, L. A.; Weismann, W. P.; Pearce, L.; Whalon, B.; Phillips, C. R.

    1997-01-01

    With the advent of space travel, it is of immediate interest and importance to study the effects of exposure to various aspects of the altered environment of space, including microgravity, on Earth-based life forms. Initial studies of space travel have focused primarily on the short-term effects of radiation and microgravity on adult organisms. However, with the potential for increased lengths of time in space, it is critical to now address the effects of space on all phases of an organism's life cycle, from embryogenesis to post-natal development to reproduction. It is already possible for certain species to undergo multiple generations within the confines of the Mir Space Station. The possibility now exists for scientists to consider the consequences of even potentially subtle defects in development through multiple phases of an organism's life cycle, or even through multiple generations. In this discussion, we highlight a few of the salient observations on the effects of the space environment on vertebrate development and reproductive function. We discuss some of the many unanswered questions, in particular, in the context of the choice of appropriate models in which to address these questions, as well as an assessment of the availability of hardware already existing or under development which would be useful in addressing these questions.

  3. Vertebrate development in the environment of space: models, mechanisms, and use of the medaka.

    PubMed

    Wolgemuth, D J; Herrada, G; Kiss, S; Cannon, T; Forsstrom, C; Pranger, L A; Weismann, W P; Pearce, L; Whalon, B; Phillips, C R

    1997-06-01

    With the advent of space travel, it is of immediate interest and importance to study the effects of exposure to various aspects of the altered environment of space, including microgravity, on Earth-based life forms. Initial studies of space travel have focused primarily on the short-term effects of radiation and microgravity on adult organisms. However, with the potential for increased lengths of time in space, it is critical to now address the effects of space on all phases of an organism's life cycle, from embryogenesis to post-natal development to reproduction. It is already possible for certain species to undergo multiple generations within the confines of the Mir Space Station. The possibility now exists for scientists to consider the consequences of even potentially subtle defects in development through multiple phases of an organism's life cycle, or even through multiple generations. In this discussion, we highlight a few of the salient observations on the effects of the space environment on vertebrate development and reproductive function. We discuss some of the many unanswered questions, in particular, in the context of the choice of appropriate models in which to address these questions, as well as an assessment of the availability of hardware already existing or under development which would be useful in addressing these questions.

  4. Vertebrate development in the environment of space: models, mechanisms, and use of the medaka

    NASA Technical Reports Server (NTRS)

    Wolgemuth, D. J.; Herrada, G.; Kiss, S.; Cannon, T.; Forsstrom, C.; Pranger, L. A.; Weismann, W. P.; Pearce, L.; Whalon, B.; Phillips, C. R.

    1997-01-01

    With the advent of space travel, it is of immediate interest and importance to study the effects of exposure to various aspects of the altered environment of space, including microgravity, on Earth-based life forms. Initial studies of space travel have focused primarily on the short-term effects of radiation and microgravity on adult organisms. However, with the potential for increased lengths of time in space, it is critical to now address the effects of space on all phases of an organism's life cycle, from embryogenesis to post-natal development to reproduction. It is already possible for certain species to undergo multiple generations within the confines of the Mir Space Station. The possibility now exists for scientists to consider the consequences of even potentially subtle defects in development through multiple phases of an organism's life cycle, or even through multiple generations. In this discussion, we highlight a few of the salient observations on the effects of the space environment on vertebrate development and reproductive function. We discuss some of the many unanswered questions, in particular, in the context of the choice of appropriate models in which to address these questions, as well as an assessment of the availability of hardware already existing or under development which would be useful in addressing these questions.

  5. Neuroprotective effect of zinc chelator DEDTC in a zebrafish (Danio rerio) Model of Hypoxic Brain Injury.

    PubMed

    Yu, Xinge; Li, Yang V

    2013-03-01

    A study was conducted using zebrafish as a model of hypoxic brain injury to investigate the potential neuroprotective effects of zinc (Zn(2+)) chelation. The accumulation of intracellular Zn(2+) is a significant causal factor of the neuronal injury, and has been implicated in cell death followed by ischemic stroke. In this study, the zebrafish was placed in the hypoxia chamber with an extremely low level of dissolved oxygen (less than 0.8 mg/L), which is similar to the conditions in a complete global ischemic stroke. Approximately 50% of zebrafish died after a short period (≈11 min) of hypoxic treatment, suggesting that this is a responsive model system for use in evaluating treatments for hypoxic brain damage. The application of DEDTC reduced intracellular Zn(2+) accumulation and produced a concentration-dependent effect by increasing the survival rate of zebrafish. Zn(2+) chelation also enhanced zebrafish tolerance for hypoxia. When the brain damages were evaluated with TTC staining, the zebrafish that were treated with DEDTC in hypoxic treatment yielded the improvement of TTC staining that was similar to the healthy zebrafish brain. The results support that rising intracellular Zn(2+) plays a critical role in the neuronal damages, and demonstrate the protective effects of Zn(2+) chelation in hypoxic-ischemic brain injury in zebrafish.

  6. Variation in wall shear stress in channel networks of zebrafish models.

    PubMed

    Choi, Woorak; Kim, Hye Mi; Park, Sungho; Yeom, Eunseop; Doh, Junsang; Lee, Sang Joon

    2017-02-01

    Physiological functions of vascular endothelial cells (ECs) vary depending on wall shear stress (WSS) magnitude, and the functional change affects the pathologies of various cardiovascular systems. Several in vitro and in vivo models have been used to investigate the functions of ECs under different WSS conditions. However, these models have technical limitations in precisely mimicking the physiological environments of ECs and monitoring temporal variations of ECs in detail. Although zebrafish (Danio rerio) has several strategies to overcome these technical limitations, zebrafish cannot be used as a perfect animal model because applying various WSS conditions on blood vessels of zebrafish is difficult. This study proposes a new zebrafish model in which various WSS can be applied to the caudal vein. The WSS magnitude is controlled by blocking some parts of blood-vessel networks. The accuracy and reproducibility of the proposed method are validated using an equivalent circuit model of blood vessels in zebrafish. The proposed method is applied to lipopolysaccharide (LPS)-stimulated zebrafish as a typical application. The proposed zebrafish model can be used as an in vivo animal model to investigate the relationship between WSS and EC physiology or WSS-induced cardiovascular diseases. © 2017 The Author(s).

  7. Utility of quantitative micro-computed tomographic analysis in zebrafish to define gene function during skeletogenesis.

    PubMed

    Charles, Julia F; Sury, Meera; Tsang, Kelly; Urso, Katia; Henke, Katrin; Huang, Yue; Russell, Ruby; Duryea, Jeffrey; Harris, Matthew P

    2017-08-01

    The zebrafish is a powerful experimental model to investigate the genetic and morphologic basis of vertebrate development. Analysis of skeletogenesis in this fish is challenging as a result of the small size of the developing and adult zebrafish. Many of the bones of small fishes such as the zebrafish and medaka are quite thin, precluding many standard assays of bone quality and morphometrics commonly used on bones of larger animals. Microcomputed tomography (microCT) is a common imaging technique used for detailed analysis of the skeleton of the zebrafish and determination of mutant phenotypes. However, the utility of this modality for analysis of the zebrafish skeleton, and the effect of inherent variation among individual zebrafish, including variables such as sex, age and strain, is not well understood. Given the increased use and accessibility of microCT, we set out to define the sensitivity of microCT methods in developing and adult zebrafish. We assessed skeletal shape and density measures in the developing vertebrae and parasphenoid of the skull base. We found most skeletal variables are tightly correlated to standard length, but that at later growth stages (>3months) there are age dependent effects on some skeletal measures. Further we find modest strain but not sex differences in skeletal measures. These data suggest that the appropriate control for assessing mutant phenotypes should be age and strain matched, ideally a wild-type sibling. By analyzing two mutants exhibiting skeletal dysplasia, we show that microCT imaging can be a sensitive method to quantify distinct skeletal parameters of adults. Finally, as developing zebrafish skeletons remain difficult to resolve by radiographic means, we define a contrast agent specific for bone that enhances resolution at early stages, permitting detailed morphometric analysis of the forming skeleton. This increased capability for detection extends the use of this imaging modality to leverage the zebrafish model to

  8. The Visual System of Zebrafish and its Use to Model Human Ocular Diseases

    PubMed Central

    Gestri, Gaia; Link, Brian A; Neuhauss, Stephan CF

    2011-01-01

    Free swimming zebrafish larvae depend mainly on their sense of vision to evade predation and to catch prey. Hence there is strong selective pressure on the fast maturation of visual function and indeed the visual system already supports a number of visually-driven behaviors in the newly hatched larvae. The ability to exploit the genetic and embryonic accessibility of the zebrafish in combination with a behavioral assessment of visual system function has made the zebrafish a popular model to study vision and its diseases. Here, we review the anatomy, physiology and development of the zebrafish eye as the basis to relate the contributions of the zebrafish to our understanding of human ocular diseases. PMID:21595048

  9. Can zebrafish be used as animal model to study Alzheimer's disease?

    PubMed Central

    Santana, Soraya; Rico, Eduardo P; Burgos, Javier S

    2012-01-01

    Zebrafish is rapidly emerging as a promising model organism to study various central nervous system (CNS) disorders, including Alzheimer’s disease (AD). AD is the main cause of dementia in the human population and there is an urgency to understand the causes of this neurodegenerative disease. In this respect, the development of new animal models to study the underlying neurodegenerative mechanisms of AD is an urgent need. In this review we analyze the current situation in the use of zebrafish as a model for AD, discussing the reasons to use this experimental paradigm in CNS investigation and analyzing the several strategies adopted to induce an AD-like pathology in zebrafish. We discuss the strategies of performing interventions to cause damage in the zebrafish brain by altering the major neurotransmitter systems (such as cholinergic, glutamatergic or GABAergic circuits). We also analyze the several transgenic zebrafish constructed for the AD study, discussing both the familial-AD models based on APP processing pathway (APP and presenilins) and in the TAU hyperphosphorylation, together with the genes involved in sporadic-AD, as apolipoprotein E. We conclude that zebrafish is in a preliminary stage of development in the AD field, and that the transgenic animals must be improved to use this fish as an optimal model for AD research. Furthermore, a deeper knowledge of the zebrafish brain and a better characterization of the injury caused by alterations in the major neurotransmitter systems are needed. PMID:23383380

  10. Absence of 11-keto reduction of cortisone and 11-ketotestosterone in the model organism zebrafish.

    PubMed

    Tsachaki, Maria; Meyer, Arne; Weger, Benjamin; Kratschmar, Denise V; Tokarz, Janina; Adamski, Jerzy; Belting, Heinz-Georg; Affolter, Markus; Dickmeis, Thomas; Odermatt, Alex

    2017-02-01

    Zebrafish are widely used as model organism. Their suitability for endocrine studies, drug screening and toxicity assessements depends on the extent of conservation of specific genes and biochemical pathways between zebrafish and human. Glucocorticoids consist of inactive 11-keto (cortisone and 11-dehydrocorticosterone) and active 11β-hydroxyl forms (cortisol and corticosterone). In mammals, two 11β-hydroxysteroid dehydrogenases (11β-HSD1 and 11β-HSD2) interconvert active and inactive glucocorticoids, allowing tissue-specific regulation of glucocorticoid action. Furthermore, 11β-HSDs are involved in the metabolism of 11-oxy androgens. As zebrafish and other teleost fish lack a direct homologue of 11β-HSD1, we investigated whether they can reduce 11-ketosteroids. We compared glucocorticoid and androgen metabolism between human and zebrafish using recombinant enzymes, microsomal preparations and zebrafish larvae. Our results provide strong evidence for the absence of 11-ketosteroid reduction in zebrafish. Neither human 11β-HSD3 nor the two zebrafish 11β-HSD3 homologues, previously hypothesized to reduce 11-ketosteroids, converted cortisone and 11-ketotestosterone (11KT) to their 11β-hydroxyl forms. Furthermore, zebrafish microsomes were unable to reduce 11-ketosteroids, and exposure of larvae to cortisone or the synthetic analogue prednisone did not affect glucocorticoid-dependent gene expression. Additionally, a dual-role of 11β-HSD2 by inactivating glucocorticoids and generating the main fish androgen 11KT was supported. Thus, due to the lack of 11-ketosteroid reduction, zebrafish and other teleost fish exhibit a limited tissue-specific regulation of glucocorticoid action, and their androgen production pathway is characterized by sustained 11KT production. These findings are of particular significance when using zebrafish as a model to study endocrine functions, stress responses and effects of pharmaceuticals. © 2017 Society for Endocrinology.

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

    SciTech Connect

    Schmidt, Hayden R.; Radić, Zoran; Taylor, Palmer; Fradinger, Erica A.

    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

  12. Defective fin regeneration in medaka fish (Oryzias latipes) with hypothyroidism.

    PubMed

    Sekimizu, Koshin; Tagawa, Masatomo; Takeda, Hiroyuki

    2007-07-01

    Wild-type medaka are known to have remarkable capabilities of fin, or epimorphic, regeneration. However, a hypothyroid mutant, kamaitachi (kmi), frequently suffers from injury in fins, suggesting an important role of thyroid hormone in fin regeneration. This led us to examine the relationship between thyroid hormone and fin regeneration using medaka as a model. For this, we first set up a medaka experimental system in which the rate of regeneration was statistically analyzed after caudal fin amputation under normal and hypothyroid conditions. As expected, the regeneration of amputated caudal fins was delayed in hypothyroid kmi -/- mutants. We then examined wild-type medaka with thiourea-induced hypothyroidism to evaluate the requirement of thyroid hormone during epimorphic fin regeneration. The results demonstrate that the growth rate of regenerates was much reduced in severely hypothyroid medaka throughout the regeneration period. This reduction in regenerative rate was recovered by exogenous administration of L-thyroxine. The present study is thus the first to report the direct involvement of thyroid hormone in teleost fin regeneration, and provides a basic framework for future molecular and genetic analyses.

  13. Effects of bioactive fatty acid amide derivatives in zebrafish scale model of bone metabolism and disease.

    PubMed

    Carnovali, M; Ottria, R; Pasqualetti, S; Banfi, G; Ciuffreda, P; Mariotti, M

    2016-02-01

    The endocannabinoid system (which includes fatty acid derivatives, receptors, and metabolizing enzymes) is involved in a variety of physiological processes, including bone metabolism in which it regulates the function of osteoblasts and osteoclasts, as well as differentiation of their precursors. The zebrafish (Danio rerio) provides a useful animal model for bone research since zebrafish bones develop rapidly and are anatomically similar to mammalian bones. Putative orthologues and paralogs of endocannabinoid genes have recently been identified in zebrafish, demonstrating the presence of cannabinoid type 1 (CB1) and type 2 (CB2) receptors with affinity to endocannabinoid ligands. To identify therapeutic molecules potentially useful in bone-related diseases, we evaluated the in vivo effects of exposure to long-chain fatty acid amides in adult zebrafish. Using a well-established zebrafish scale model, we found that anandamide and N-linoleoylethanolamine are able to stimulate bone formation by increasing alkaline phosphatase activity in physiological conditions. In addition, they prevent the alteration of bone markers in a prednisolone-induced osteoporosis model in adult zebrafish scales, whereas their esterified forms do not. These data suggest that long-chain fatty acid amides are involved in regulating bone metabolism in zebrafish scales and that the CB2 receptor is a key mediator in this process.

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

    PubMed

    Schmidt, Hayden R; Radić, Zoran; Taylor, Palmer; Fradinger, Erica A

    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 ki 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, kr, in both zebrafish and human AChE. However, differences between the Kox and k2 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, Ki and αKi, 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.

  15. A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

    PubMed Central

    Huang, Liwei; Xiao, An; Wecker, Andrea; McBride, Daniel A.; Choi, Soo Young; Zhou, Weibin; Lipschutz, Joshua H.

    2014-01-01

    Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to “off-target” effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney. PMID:25489842

  16. A possible zebrafish model of polycystic kidney disease: knockdown of wnt5a causes cysts in zebrafish kidneys.

    PubMed

    Huang, Liwei; Xiao, An; Wecker, Andrea; McBride, Daniel A; Choi, Soo Young; Zhou, Weibin; Lipschutz, Joshua H

    2014-12-02

    Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to "off-target" effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

  17. Zebrafish as a model for monocarboxyl transporter 8-deficiency.

    PubMed

    Vatine, Gad David; Zada, David; Lerer-Goldshtein, Tali; Tovin, Adi; Malkinson, Guy; Yaniv, Karina; Appelbaum, Lior

    2013-01-04

    Allan-Herndon-Dudley syndrome (AHDS) is a severe psychomotor retardation characterized by neurological impairment and abnormal thyroid hormone (TH) levels. Mutations in the TH transporter, monocarboxylate transporter 8 (MCT8), are associated with AHDS. MCT8 knock-out mice exhibit impaired TH levels; however, they lack neurological defects. Here, the zebrafish mct8 gene and promoter were isolated, and mct8 promoter-driven transgenic lines were used to show that, similar to humans, mct8 is primarily expressed in the nervous and vascular systems. Morpholino-based knockdown and rescue experiments revealed that MCT8 is strictly required for neural development in the brain and spinal cord. This study shows that MCT8 is a crucial regulator during embryonic development and establishes the first vertebrate model for MCT8 deficiency that exhibits a neurological phenotype.

  18. A zebrafish (Danio rerio) model of infectious spleen and kidney necrosis virus (ISKNV) infection

    SciTech Connect

    Xu Xiaopeng; Zhang Lichun; Weng Shaoping; Huang Zhijian; Lu Jing; Lan Dongming; Zhong Xuejun; Yu Xiaoqiang; Xu Anlong He Jianguo

    2008-06-20

    Zebrafish is a model animal for studies of genetics, development, toxicology, oncology, and immunology. In this study, infectious spleen and kidney necrosis virus (ISKNV) was used to establish an infection in zebrafish, and the experimental conditions were established and characterized. Mortality of adult zebrafish infected with ISKNV by intraperitoneal (i.p.) injection exceeded 60%. ISKNV can be passed stably in zebrafish for over ten passages. The ailing zebrafish displayed petechial hemorrhaging and scale protrusion. Histological analysis of moribund fish revealed necrosis of tissue and enlarged cells in kidney and spleen. The real-time RT-PCR analysis of mRNA level confirmed that ISKNV was replicated in zebrafish. Immunohistochemistry and immunofluorescence analyses further confirmed the presence of ISKNV-infected cells in almost all organs of the infected fish. Electron microscope analyses showed that the ISKNV particle was present in the infected tissues. The establishment of zebrafish infection model of ISKNV can offer a valuable tool for studying the interactions between ISKNV and its host.

  19. A zebrafish (Danio rerio) model of infectious spleen and kidney necrosis virus (ISKNV) infection.

    PubMed

    Xu, Xiaopeng; Zhang, Lichun; Weng, Shaoping; Huang, Zhijian; Lu, Jing; Lan, Dongming; Zhong, Xuejun; Yu, Xiaoqiang; Xu, Anlong; He, Jianguo

    2008-06-20

    Zebrafish is a model animal for studies of genetics, development, toxicology, oncology, and immunology. In this study, infectious spleen and kidney necrosis virus (ISKNV) was used to establish an infection in zebrafish, and the experimental conditions were established and characterized. Mortality of adult zebrafish infected with ISKNV by intraperitoneal (i.p.) injection exceeded 60%. ISKNV can be passed stably in zebrafish for over ten passages. The ailing zebrafish displayed petechial hemorrhaging and scale protrusion. Histological analysis of moribund fish revealed necrosis of tissue and enlarged cells in kidney and spleen. The real-time RT-PCR analysis of mRNA level confirmed that ISKNV was replicated in zebrafish. Immunohistochemistry and immunofluorescence analyses further confirmed the presence of ISKNV-infected cells in almost all organs of the infected fish. Electron microscope analyses showed that the ISKNV particle was present in the infected tissues. The establishment of zebrafish infection model of ISKNV can offer a valuable tool for studying the interactions between ISKNV and its host.

  20. Establishment of a congenital amegakaryocytic thrombocytopenia model and a thrombocyte-specific reporter line in zebrafish.

    PubMed

    Lin, Q; Zhang, Y; Zhou, R; Zheng, Y; Zhao, L; Huang, M; Zhang, X; Leung, A Y H; Zhang, W; Zhang, Y

    2016-11-29

    Mutations in the human myeloproliferative leukemia (MPL) protein gene are known to cause congenital amegakaryocytic thrombocytopenia (CAMT). The prognosis of this heritable disorder is poor and bone marrow transplantation is the only effective treatment. Here, by using the TALEN (transcription activator-like effector nuclease) technology, we created a zebrafish mpl mutant to model human CAMT. Disruption of zebrafish mpl lead to a severe reduction in thrombocytes and a high bleeding tendency, as well as deficiencies in adult hematopoietic stem/progenitor cells. We further demonstrated that thrombocytopenia in mpl mutant zebrafish was caused by impaired Tpo/Mpl/Jak2 signaling, resulting in reduced proliferation of thrombocyte precursors. These results indicate that mpl mutant zebrafish develop thrombocytopenia resembling the human CAMT. To utilize fully zebrafish to study thrombocyte biology and thrombocytopenia disorders, we generated a transgenic reporter line Tg(mpl:eGFP)smu4, in which green fluorescent protein (GFP) expression was driven by the mpl promoter. Detailed characterization of Tg(mpl:eGFP)smu4 fish confirmed that the thrombocyte lineage was specifically marked by GFP expression. In conclusion, we generated the first transmissible congenital thrombocytopenia zebrafish model mimicking human CAMT and a thrombocyte-specific transgenic line. Together with Tg(mpl:eGFP)smu4, mpl mutant zebrafish provide a useful tool for drug screening and study of thrombocytopoiesis.Leukemia advance online publication, 29 November 2016; doi:10.1038/leu.2016.320.

  1. [Establishment of a diet-induced obesity model in zebrafish larvae].

    PubMed

    Zheng, Xinchun; Liu, Li; Dai, Wencong; Wang, Kunyuan; Chen, Xiaohui; Zhao, Lingfeng; Huang, Zhibin; Hou, Jinlin

    2016-01-01

    To establish a diet-induced obesity model in zebrafish larvae. At 7 days post-fertilization (dpf), 200 zebrafish larvae with normal development were randomly allocated to two groups with the feeding quantity of 30 mg per day (normal feeding group) or 180 mg per day (overfed group) for 20 days. The weight, length, BMI, triglyceride (TG) and total cholesterol (TCH) of each group were measured. Whole-mount Oil Red O staining, frozen Oil Red O staining and hematoxylin-eosin (HE) staining were used to estimate the rate of hepatic steatosis and liver histology of the zebrafish. The dynamic change of hepatic lipid droplets and distribution of adipose tissue were observed with Nile Red staining in overfed zebrafish in vivo. The weight, length, BMI and TG of overfed zebrafish were significantly increased compared with those in normal feeding group. Whole-mount Oil Red O staining showed that the percent of hepatic steatosis in overfed group (89.4%) was markedly higher than that in normal feeding group (20.7%). Macrovesicular steatosis was observed in the liver of the overfed larvae. Nile Red staining visualized hepatic lipid droplets and the distribution of larval adipose tissue, which increased with feeding time in the overfed zebrafish. Starving larvae showed depletion of fat and hepatic lipid, and adipose tissue was induced after refeeding. We successfully established an diet-induced obesity model in zebrafish larva, in which Nile Red staining allows in vivo observation of the adipocytes and hepatic lipid droplets.

  2. A zebrafish xenograft model for studying human cancer stem cells in distant metastasis and therapy response.

    PubMed

    Chen, L; Groenewoud, A; Tulotta, C; Zoni, E; Kruithof-de Julio, M; van der Horst, G; van der Pluijm, G; Ewa Snaar-Jagalska, B

    2017-01-01

    Lethal and incurable bone metastasis is one of the main causes of death in multiple types of cancer. A small subpopulation of cancer stem/progenitor-like cells (CSCs), also known as tumor-initiating cells from heterogenetic cancer is considered to mediate bone metastasis. Although over the past decades numerous studies have been performed in different types of cancer, it is still difficult to track small numbers of CSCs during the onset of metastasis. With use of noninvasive high-resolution imaging, transparent zebrafish embryos can be employed to dynamically visualize cancer progression and reciprocal interaction with stroma in a living organism. Recently we established a zebrafish CSC-xenograft model to visually and functionally analyze the role of CSCs and their interactions with the microenvironment at the onset of metastasis. Given the highly conserved human and zebrafish genome, transplanted human cancer cells are able to respond to zebrafish cytokines, modulate the zebrafish microenvironment, and take advantage of the zebrafish stroma during cancer progression. This chapter delineates the zebrafish CSC-xenograft model as a useful tool for both CSC biological study and anticancer drug screening. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Zebrafish – As an Integrative Model for Twenty-first Century Toxicity Testing

    EPA Science Inventory

    The zebrafish embryo is a useful small model for investigating vertebrate development because of its transparency, low cost, transgenic and morpholino capabilities, conservation of cell signaling, and concordance with mammalian developmental phenotypes. From these advantages, the...

  4. The Texas-Indiana Virtual STAR Center: Zebrafish Models for Developmental Toxicity Screening

    EPA Pesticide Factsheets

    The Texas-Indiana Virtual STAR Center: Zebrafish Models for Developmental Toxicity Screening (Presented by Maria Bondesson Bolin, Ph.D, University of Houston, Center for Nuclear Receptors and Cell Signaling) (3/22/2012)

  5. Zebrafish – As an Integrative Model for Twenty-first Century Toxicity Testing

    EPA Science Inventory

    The zebrafish embryo is a useful small model for investigating vertebrate development because of its transparency, low cost, transgenic and morpholino capabilities, conservation of cell signaling, and concordance with mammalian developmental phenotypes. From these advantages, the...

  6. Molecular and cellular markers of toxicity in the Japanese Medaka @

    SciTech Connect

    Shugart, L.R.; McCarthy, J.F.; D'Surney, S.J.; Greeley, M.S. Jr.; Hull, C.G.

    1990-01-01

    The Japanese Medaka (Oryzias latipes) has been recommended for use as a model organism to detect carcinogenic, teratogenic, cytotoxic, and genotoxic compounds in aquatic systems. Because a long latent period often occurs between initial contact with deleterious chemicals and subsequent expression of the pathology, we are investigating early biologically-relevant responses that can be used as genotoxicity markers of exposure and effect. This project focuses on the development of genotoxic bioassays and experimental protocols for exposing Japanese Medaka to genotoxic compounds. 21 refs., 8 figs, 2 tabs.

  7. Robotic injection of zebrafish embryos for high-throughput screening in disease models.

    PubMed

    Spaink, Herman P; Cui, Chao; Wiweger, Malgorzata I; Jansen, Hans J; Veneman, Wouter J; Marín-Juez, Rubén; de Sonneville, Jan; Ordas, Anita; Torraca, Vincenzo; van der Ent, Wietske; Leenders, William P; Meijer, Annemarie H; Snaar-Jagalska, B Ewa; Dirks, Ron P

    2013-08-15

    The increasing use of zebrafish larvae for biomedical research applications is resulting in versatile models for a variety of human diseases. These models exploit the optical transparency of zebrafish larvae and the availability of a large genetic tool box. Here we present detailed protocols for the robotic injection of zebrafish embryos at very high accuracy with a speed of up to 2000 embryos per hour. These protocols are benchmarked for several applications: (1) the injection of DNA for obtaining transgenic animals, (2) the injection of antisense morpholinos that can be used for gene knock-down, (3) the injection of microbes for studying infectious disease, and (4) the injection of human cancer cells as a model for tumor progression. We show examples of how the injected embryos can be screened at high-throughput level using fluorescence analysis. Our methods open up new avenues for the use of zebrafish larvae for large compound screens in the search for new medicines.

  8. Building Finite Element Models to Investigate Zebrafish Jaw Biomechanics

    PubMed Central

    Brunt, Lucy H.; Roddy, Karen A.; Rayfield, Emily J.; Hammond, Chrissy L.

    2016-01-01

    Skeletal morphogenesis occurs through tightly regulated cell behaviors during development; many cell types alter their behavior in response to mechanical strain. Skeletal joints are subjected to dynamic mechanical loading. Finite element analysis (FEA) is a computational method, frequently used in engineering that can predict how a material or structure will respond to mechanical input. By dividing a whole system (in this case the zebrafish jaw skeleton) into a mesh of smaller 'finite elements', FEA can be used to calculate the mechanical response of the structure to external loads. The results can be visualized in many ways including as a 'heat map' showing the position of maximum and minimum principal strains (a positive principal strain indicates tension while a negative indicates compression. The maximum and minimum refer the largest and smallest strain). These can be used to identify which regions of the jaw and therefore which cells are likely to be under particularly high tensional or compressional loads during jaw movement and can therefore be used to identify relationships between mechanical strain and cell behavior. This protocol describes the steps to generate Finite Element models from confocal image data on the musculoskeletal system, using the zebrafish lower jaw as a practical example. The protocol leads the reader through a series of steps: 1) staining of the musculoskeletal components, 2) imaging the musculoskeletal components, 3) building a 3 dimensional (3D) surface, 4) generating a mesh of Finite Elements, 5) solving the FEA and finally 6) validating the results by comparison to real displacements seen in movements of the fish jaw. PMID:28060270

  9. Studies on sensitivity of zebrafish as a model organism for Parkinson's disease: Comparison with rat model

    PubMed Central

    Makhija, Dinesh T.; Jagtap, Aarti G.

    2014-01-01

    Objective: To determine the utility of zebra fish as an animal model for Parkinson's disease (PD) in comparison with rat model. Materials and Methods: MTT assay was performed on rat and zebrafish brain synaptosomal fractions using rotenone as a neurotoxic agent. Quercetin and resveratrol were used as standards to compare anti-apoptotic activity in both organisms. Catalepsy was induced in zebrafish by exposing them to haloperidol (9 μM) solution. Drug-treated groups were exposed to bromocriptine and pramipexole, 30 min prior to haloperidol exposure at the dose of 2, 5, and 10 μg/mL. Swimming speed, time spent in the bottom of the tank, and complete cataleptic time were evaluated to assess behavioral changes. In rats, catalepsy was induced using haloperidol (1.25 mg/kg i.p.). Drug-treated groups received bromocriptine (2.5 mg/kg.) and pramipexole (1 mg/kg) orally. Bar test, block test, and locomotor activity were carried out to assess behavioral changes. Results: Resveratrol and quercetin showed comparable inhibition of apoptosis in rats and zebrafish. In anti-cataleptic study, bromocriptine and pramipexole-treated groups showed significant difference (P < 0.05) in behavioral parameters as compared to haloperidol control group in both the experimental organisms. Results obtained from fish model were in correlation with rat model. Conclusion: Findings of the present study revealed that zebrafish model is highly sensitive and can be used for basic screening of drugs against PD. PMID:24554909

  10. Zebrafish as an In Vivo Model to Assess Epigenetic Effects of Ionizing Radiation

    PubMed Central

    Kong, Eva Yi; Cheng, Shuk Han; Yu, Kwan Ngok

    2016-01-01

    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. PMID:27983682

  11. Zebrafish as an In Vivo Model to Assess Epigenetic Effects of Ionizing Radiation.

    PubMed

    Kong, Eva Yi; Cheng, Shuk Han; Yu, Kwan Ngok

    2016-12-15

    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.

  12. Zebrafish: A Versatile Animal Model for Fertility Research.

    PubMed

    Hoo, Jing Ying; Kumari, Yatinesh; Shaikh, Mohd Farooq; Hue, Seow Mun; Goh, Bey Hing

    2016-01-01

    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.

  13. Zebrafish: A Versatile Animal Model for Fertility Research

    PubMed Central

    Hoo, Jing Ying; Kumari, Yatinesh; Shaikh, Mohd Farooq; Hue, Seow Mun

    2016-01-01

    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. PMID:27556045

  14. Zebrafish as a Potential Model Organism for Drug Test Against Hepatitis C Virus

    PubMed Central

    Ding, Cun-Bao; Zhang, Jing-Pu; Zhao, Ye; Peng, Zong-Gen; Song, Dan-Qing; Jiang, Jian-Dong

    2011-01-01

    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. PMID:21857967

  15. A novel early onset phenotype in a zebrafish model of merosin deficient congenital muscular dystrophy

    PubMed Central

    Smith, Sarah J.; Wang, Jeffrey C.; Gupta, Vandana A.; Dowling, James J.

    2017-01-01

    Merosin deficient congenital muscular dystrophy (MDC1A) is a severe neuromuscular disorder with onset in infancy that is associated with severe morbidities (particularly wheelchair dependence) and early mortality. It is caused by recessive mutations in the LAMA2 gene that encodes a subunit of the extracellular matrix protein laminin 211. At present, there are no treatments for this disabling disease. The zebrafish has emerged as a powerful model system for the identification of novel therapies. However, drug discovery in the zebrafish is largely dependent on the identification of phenotypes suitable for chemical screening. Our goal in this study was to elucidate novel, early onset abnormalities in the candyfloss (caf) zebrafish, a model of MDC1A. We uncovered and characterize abnormalities in spontaneous coiling, the earliest motor movement in the zebrafish, as a fully penetrant change specific to caf mutants that is ideal for future drug testing. PMID:28241031

  16. Modelling viral infections using zebrafish: Innate immune response and antiviral research.

    PubMed

    Varela, Mónica; Figueras, Antonio; Novoa, Beatriz

    2017-03-01

    Zebrafish possess a highly developed immune system that is remarkably similar to the human one. Therefore, it is expected that the majority of the signalling pathways and molecules involved in the immune response of mammals exist and behave similarly in fish. The innate antiviral response depends on the recognition of viral components by host cells. Pattern recognition receptors initiate antimicrobial defence mechanisms via several well-conserved signalling pathways. In this paper, we review current knowledge of the antiviral innate immune response in zebrafish by considering the main molecules that have been characterized and the infection models used for the in vivo study of the antiviral innate immune response. We next summarize published studies in which larval and adult zebrafish were used to study viral diseases of fish, then provide a similar review of studies of human viral diseases in zebrafish and experience with antiviral drug screening in this model organism. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Establishment of multi-site infection model in zebrafish larvae for studying Staphylococcus aureus infectious disease.

    PubMed

    Li, Ya-juan; Hu, Bing

    2012-09-20

    Zebrafish (Danio rerio) is an ideal model for studying the mechanism of infectious disease and the interaction between host and pathogen. As a teleost, zebrafish has developed a complete immune system which is similar to mammals. Moreover, the easy acquirement of large amounts of transparent embryos makes it a good candidate for gene manipulation and drug screening. In a zebrafish infection model, all of the site, timing, and dose of the bacteria microinjection into the embryo are important factors that determine the bacterial infection of host. Here, we established a multi-site infection model in zebrafish larvae of 36 hours post-fertilization (hpf) by microinjecting wild-type or GFP-expressing Staphylococcus aereus (S. aureus) with gradient burdens into different embryo sites including the pericardial cavity (PC), eye, the fourth hindbrain ventricle (4V), yolk circulation valley (YCV), caudal vein (CV), yolk body (YB), and Duct of Cuvier (DC) to resemble human infectious disease. With the combination of GFP-expressing S. aureus and transgenic zebrafish Tg (coro1a: eGFP; lyz: Dsred) and Tg (lyz: Dsred) lines whose macrophages or neutrophils are fluorescent labeled, we observed the dynamic process of bacterial infection by in vivo multicolored confocal fluorescence imaging. Analyses of zebrafish embryo survival, bacterial proliferation and myeloid cells phagocytosis show that the site- and dose-dependent differences exist in infection of different bacterial entry routes. This work provides a consideration for the future study of pathogenesis and host resistance through selection of multi-site infection model. More interaction mechanisms between pathogenic bacteria virulence factors and the immune responses of zebrafish could be determined through zebrafish multi-site infection model.

  18. Characterization of fish schooling behavior with different numbers of Medaka (Oryzias latipes) and goldfish (Carassius auratus) using a Hidden Markov Model

    NASA Astrophysics Data System (ADS)

    Jeon, Wonju; Kang, Seung-Ho; Leem, Joo-Baek; Lee, Sang-Hee

    2013-05-01

    Fish that swim in schools benefit from increased vigilance, and improved predator recognition and assessment. Fish school size varies according to species and environmental conditions. In this study, we present a Hidden Markov Model (HMM) that we use to characterize fish schooling behavior in different sized schools, and explore how school size affects schooling behavior. We recorded the schooling behavior of Medaka (Oryzias latipes) and goldfish (Carassius auratus) using different numbers of individual fish (10-40), in a circular aquarium. Eight to ten 3 s video clips were extracted from the recordings for each group size. Schooling behavior was characterized by three variables: linear speed, angular speed, and Pearson coefficient. The values of the variables were categorized into two events each for linear and angular speed (high and low), and three events for the Pearson coefficient (high, medium, and low). Schooling behavior was then described as a sequence of 12 events (2×2×3), which was input to an HMM as data for training the model. Comparisons of model output with observations of actual schooling behavior demonstrated that the HMM was successful in characterizing fish schooling behavior. We briefly discuss possible applications of the HMM for recognition of fish species in a school, and for developing bio-monitoring systems to determine water quality.

  19. Zebrafish Models of Prader-Willi Syndrome: Fast Track to Pharmacotherapeutics

    PubMed Central

    Spikol, Emma D.; Laverriere, Caroline E.; Robnett, Maya; Carter, Gabriela; Wolfe, Erin; Glasgow, Eric

    2016-01-01

    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. PMID:27857842

  20. LITTLE FISH, BIG DATA: ZEBRAFISH AS A MODEL FOR CARDIOVASCULAR AND METABOLIC DISEASE.

    PubMed

    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.

  1. Modeling pegylated liposomal doxorubicin-induced hand-foot syndrome and intestinal mucositis in zebrafish

    PubMed Central

    Chen, Yau-Hung; Lee, Ya-Ting; Wen, Chi-Chung; Chen, Yun-Chen; Chen, Yu-Jen

    2014-01-01

    Pegylated liposomal doxorubicin (PLD) has been widely used to treat cancer. The adverse effects of PLD noted in clinical practice, especially hand-foot syndrome (HFS), are regarded as unique, and the management methods for them remain limited. This study was aimed at developing a feasible experimental model for translational medicine to solve this clinical issue by using skin fluorescent transgenic zebrafish. We established an optimal protocol for the administration of Lipo-Dox™, a PLD in current clinical use, to the Tg(k18:dsred) zebrafish line expressing red fluorescence in keratinocytes. We made use of bodyweight, survival rate, gross observation, flssuorescent microscopic assessment, and pathological examination of the zebrafish to assess this model. The consecutive administration protocol of PLD resulted in growth retardation of the zebrafish embryo and survival impairment, indicating establishment of a significant toxicity. We observed fin necrosis and keratinocyte dissociation phenotypes in the PLD-treated fish after consecutive administration. The skin toxicity induced by the Lipo-Dox injection was subsequently reversible, which might be compatible with a clinical course of skin recovery after discontinuation of Lipo-Dox administration. Furthermore, we found that the number of intestinal goblet cells, an important marker of intestinal inflammation, in the Lipo-Dox-injected zebrafish was markedly increased, accompanied by impaired mucosal integrity. The intestinal inflammation induced by Lipo-Dox resembled the intestinal mucositis the clinical patients suffered from after the administration of PLD. In conclusion, we established a zebrafish model for PLD-induced HFS. The intestinal mucositis simultaneously noted in the PLD-treated zebrafish validated the similarity of clinical courses after administration of PLD. This model is easily assessable, efficient, and worthy for use in developing a new therapeutic protocol for prevention or treatment of HFS as well

  2. Microbial fingerprinting detects intestinal microbiota dysbiosis in Zebrafish models with chemically-induced enterocolitis

    PubMed Central

    2013-01-01

    Background Inflammatory bowel disease (IBD) involves a breakdown in interactions between the host immune response and the resident commensal microbiota. Recent studies have suggested gut physiology and pathology relevant to human IBD can be rapidly modeled in zebrafish larvae. The aim of this study was to investigate the dysbiosis of intestinal microbiota in zebrafish models with IBD-like enterocolitis using culture-independent techniques. Results IBD-like enterocolitis was induced by exposing larval zebrafish to trinitrobenzenesulfonic acid (TNBS). Pathology was assessed by histology and immunofluorescence. Changes in intestinal microbiota were evaluated by denaturing gradient gel electrophoresis (DGGE) and the predominant bacterial composition was determined with DNA sequencing and BLAST and confirmed by real-time polymerase chain reaction. Larval zebrafish exposed to TNBS displayed intestinal-fold architecture disruption and inflammation reminiscent of human IBD. In this study, we defined a reduced biodiversity of gut bacterial community in TNBS-induced coliitis. The intestinal microbiota dysbiosis in zebrafish larvae with IBD-like colitis was characterized by an increased proportion of Proteobacteria (especially Burkholderia) and a decreased of Firmicutes(Lactobacillus group), which were significantly correlated with enterocolitis severity(Pearson correlation p < 0.01). Conclusions This is the first description of intestinal microbiota dysbiosis in zebrafish IBD-like models, and these changes correlate with TNBS-induced enterocolitis. Prevention or reversal of this dysbiosis may be a viable option for reducing the incidence and severity of human IBD. PMID:24325678

  3. The Zebrafish Model Organism Database: new support for human disease models, mutation details, gene expression phenotypes and searching

    PubMed Central

    Howe, Douglas G.; Bradford, Yvonne M.; Eagle, Anne; Fashena, David; Frazer, Ken; Kalita, Patrick; Mani, Prita; Martin, Ryan; Moxon, Sierra Taylor; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruzicka, Leyla; Schaper, Kevin; Shao, Xiang; Singer, Amy; Toro, Sabrina; Van Slyke, Ceri; Westerfield, Monte

    2017-01-01

    The Zebrafish Model Organism Database (ZFIN; http://zfin.org) is the central resource for zebrafish (Danio rerio) genetic, genomic, phenotypic and developmental data. ZFIN curators provide expert manual curation and integration of comprehensive data involving zebrafish genes, mutants, transgenic constructs and lines, phenotypes, genotypes, gene expressions, morpholinos, TALENs, CRISPRs, antibodies, anatomical structures, models of human disease and publications. We integrate curated, directly submitted, and collaboratively generated data, making these available to zebrafish research community. Among the vertebrate model organisms, zebrafish are superbly suited for rapid generation of sequence-targeted mutant lines, characterization of phenotypes including gene expression patterns, and generation of human disease models. The recent rapid adoption of zebrafish as human disease models is making management of these data particularly important to both the research and clinical communities. Here, we describe recent enhancements to ZFIN including use of the zebrafish experimental conditions ontology, ‘Fish’ records in the ZFIN database, support for gene expression phenotypes, models of human disease, mutation details at the DNA, RNA and protein levels, and updates to the ZFIN single box search. PMID:27899582

  4. The Zebrafish Model Organism Database: new support for human disease models, mutation details, gene expression phenotypes and searching.

    PubMed

    Howe, Douglas G; Bradford, Yvonne M; Eagle, Anne; Fashena, David; Frazer, Ken; Kalita, Patrick; Mani, Prita; Martin, Ryan; Moxon, Sierra Taylor; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruzicka, Leyla; Schaper, Kevin; Shao, Xiang; Singer, Amy; Toro, Sabrina; Van Slyke, Ceri; Westerfield, Monte

    2017-01-04

    The Zebrafish Model Organism Database (ZFIN; http://zfin.org) is the central resource for zebrafish (Danio rerio) genetic, genomic, phenotypic and developmental data. ZFIN curators provide expert manual curation and integration of comprehensive data involving zebrafish genes, mutants, transgenic constructs and lines, phenotypes, genotypes, gene expressions, morpholinos, TALENs, CRISPRs, antibodies, anatomical structures, models of human disease and publications. We integrate curated, directly submitted, and collaboratively generated data, making these available to zebrafish research community. Among the vertebrate model organisms, zebrafish are superbly suited for rapid generation of sequence-targeted mutant lines, characterization of phenotypes including gene expression patterns, and generation of human disease models. The recent rapid adoption of zebrafish as human disease models is making management of these data particularly important to both the research and clinical communities. Here, we describe recent enhancements to ZFIN including use of the zebrafish experimental conditions ontology, 'Fish' records in the ZFIN database, support for gene expression phenotypes, models of human disease, mutation details at the DNA, RNA and protein levels, and updates to the ZFIN single box search.

  5. Assessing the Value of the Zebrafish Conditioned Place Preference Model for Predicting Human Abuse Potential.

    PubMed

    Brock, A J; Goody, S M G; Mead, A N; Sudwarts, A; Parker, M O; Brennan, C H

    2017-10-01

    Regulatory agencies recommend that centrally active drugs are tested for abuse potential before approval. Standard preclinical assessments are conducted in rats or non-human primates (NHPs). This study evaluated the ability of the zebrafish conditioned place preference (CPP) model to predict human abuse outcomes. Twenty-seven compounds from a variety of pharmacological classes were tested in zebrafish CPP, categorized as positive or negative, and analyzed using standard diagnostic tests of binary classification to determine the likelihood that zebrafish correctly predict robust positive signals in human subjective effects studies (+HSE) and/or Drug Enforcement Administration drug scheduling. Results were then compared with those generated for rat self-administration and CPP, as well as NHP self-administration, using this same set of compounds. The findings reveal that zebrafish concordance and sensitivity values were not significantly different from chance for both +HSE and scheduling. Although significant improvements in specificity and negative predictive values were observed for zebrafish relative to +HSE, specificity without sensitivity provides limited predictive value. Moreover, assessments in zebrafish provided no added value for predicting scheduling. By contrast, rat and NHP models generally possessed significantly improved concordance, sensitivity, and positive predictive values for both clinical measures. Although there may be predictive value with compounds from specific pharmacological classes (e.g., µ-opioid receptor agonists, psychostimulants) for zebrafish CPP, altogether these data highlight that using the current methodology, the zebrafish CPP model does not add value to the preclinical assessment of abuse potential. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  6. Zebrafish as a Model for Cancer Self-Renewal

    PubMed Central

    Ignatius, Myron S.

    2009-01-01

    Abstract Self-renewal is the process by which normal stem cells and cancer cells make more of themselves. In cancer, this process is ultimately responsible for the infinite replicative potential of malignant cells and is likely found in residual cell populations that evade conventional therapy. Two intrinsically opposing hypotheses have emerged to explain how self-renewal occurs in cancer. The cancer stem cell hypothesis states that self-renewal is confined to a discrete subpopulation of malignant cells, whereas the stochastic model suggests that all tumor cells have the potential to self-renew. Presently, the gold standard for measuring cancer self-renewal is limiting dilution cell transplantation into immune-matched or immune-deficient animals. From these experiments, tumor-initiating frequency can be calculated based on the number of animals that engraft disease following transplantation of various doses of tumor cells. Here, we describe how self-renewal assays are performed, summarize the current experimental models that support the cancer stem cell and stochastic models of cancer self-renewal, and enumerate how the zebrafish can be used to uncover important pathways in cancer self-renewal. PMID:19954344

  7. Evaluation of the physiology of Medaka as a model animal for standardized toxicity tests of chemicals by using mRNA expression profiling.

    PubMed

    Iwahashi, Hitoshi; Kishi, Katsuyuki; Kitagawa, Emiko; Suzuki, Katsunori; Hayashi, Yasuyuki

    2009-05-15

    The fish acute toxicity test in the Organisation for Economic CoOperation and Development "OECD Guidelines for Testing of Chemicals" is an essential test for environmental toxicity. Here, we have tried to evaluate the physiology of medaka during these test procedures by using genomics. Genomics technology can provide genome-wide expression profiles of mRNA, and these profiles correspond to the physiology of organisms. Thus, a comparison of mRNA expression profiles gives information on the reproducibility of experimental conditions. Expression profiles of mRNA were measured for medakas maintained within the allowable range of the test conditions and also under extreme conditions beyond the guideline limits. We confirmed the high physiological reproducibility of medaka kept in the recommended conditions of the fish acute toxicity test in the "OECD Guidelines for Testing of Chemicals" from the expression profiles obtained under all experimental conditions, except for the types of feeding.

  8. A transgenic zebrafish model for monitoring glucocorticoid receptor activity

    PubMed Central

    Krug, Randall G.; Poshusta, Tanya L.; Skuster, Kimberly J.; Berg, MaKayla R.; Gardner, Samantha L.; Clark, Karl J.

    2014-01-01

    Gene regulation resulting from glucocorticoid receptor and glucocorticoid response element interactions is a hallmark feature of stress response signaling. Imbalanced glucocorticoid production and glucocorticoid receptor activity have been linked to socio-economically crippling neuropsychiatric disorders, and accordingly there is a need to develop in vivo models to help understand disease progression and management. Therefore, we developed the transgenic SR4G zebrafish reporter line with six glucocorticoid response elements used to promote expression of a short half-life green fluorescent protein following glucocorticoid receptor activation. Herein, we document the ability of this reporter line to respond to both chronic and acute exogenous glucocorticoid treatment. The green fluorescent protein expression in response to transgene activation was high in a variety of tissues including the brain, and provided single cell resolution in the effected regions. The specificity of these responses is demonstrated using the partial agonist mifepristone and mutation of the glucocorticoid receptor. Importantly, the reporter line also modeled the temporal dynamics of endogenous stress response signaling, including the increased production of the glucocorticoid cortisol following hyperosmotic stress and the fluctuations of basal cortisol concentrations with the circadian rhythm. Taken together, these results characterize our newly developed reporter line for elucidating environmental or genetic modifiers of stress response signaling, which may provide insights to the neuronal mechanisms underlying neuropsychiatric disorders such as major depressive disorder. PMID:24679220

  9. Phylogeny of Zebrafish, a “Model Species,” within Danio, a “Model Genus”

    PubMed Central

    McCluskey, Braedan M.; Postlethwait, John H.

    2015-01-01

    Zebrafish (Danio rerio) is an important model for vertebrate development, genomics, physiology, behavior, toxicology, and disease. Additionally, work on numerous Danio species is elucidating evolutionary mechanisms for morphological development. Yet, the relationships of zebrafish and its closest relatives remain unclear possibly due to incomplete lineage sorting, speciation with gene flow, and interspecies hybridization. To clarify these relationships, we first constructed phylogenomic data sets from 30,801 restriction-associated DNA (RAD)-tag loci (483,026 variable positions) with clear orthology to a single location in the sequenced zebrafish genome. We then inferred a well-supported species tree for Danio and tested for gene flow during the diversification of the genus. An approach independent of the sequenced zebrafish genome verified all inferred relationships. Although identification of the sister taxon to zebrafish has been contentious, multiple RAD-tag data sets and several analytical methods provided strong evidence for Danio aesculapii as the most closely related extant zebrafish relative studied to date. Data also displayed patterns consistent with gene flow during speciation and postspeciation introgression in the lineage leading to zebrafish. The incorporation of biogeographic data with phylogenomic analyses put these relationships in a phylogeographic context and supplied additional support for D. aesculapii as the sister species to D. rerio. The clear resolution of this study establishes a framework for investigating the evolutionary biology of Danio and the heterogeneity of genome evolution in the recent history of a model organism within an emerging model genus for genetics, development, and evolution. PMID:25415969

  10. Fishing for Nature's Hits: Establishment of the Zebrafish as a Model for Screening Antidiabetic Natural Products

    PubMed Central

    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. PMID:26681965

  11. Zebrafish as a Model Organism for the Development of Drugs for Skin Cancer.

    PubMed

    Bootorabi, Fatemeh; Manouchehri, Hamed; Changizi, Reza; Barker, Harlan; Palazzo, Elisabetta; Saltari, Annalisa; Parikka, Mataleena; Pincelli, Carlo; Aspatwar, Ashok

    2017-07-18

    Skin cancer, which includes melanoma and squamous cell carcinoma, represents the most common type of cutaneous malignancy worldwide, and its incidence is expected to rise in the near future. This condition derives from acquired genetic dysregulation of signaling pathways involved in the proliferation and apoptosis of skin cells. The development of animal models has allowed a better understanding of these pathomechanisms, with the possibility of carrying out toxicological screening and drug development. In particular, the zebrafish (Danio rerio) has been established as one of the most important model organisms for cancer research. This model is particularly suitable for live cell imaging and high-throughput drug screening in a large-scale fashion. Thanks to the recent advances in genome editing, such as the clustered regularly-interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) methodologies, the mechanisms associated with cancer development and progression, as well as drug resistance can be investigated and comprehended. With these unique tools, the zebrafish represents a powerful platform for skin cancer research in the development of target therapies. Here, we will review the advantages of using the zebrafish model for drug discovery and toxicological and phenotypical screening. We will focus in detail on the most recent progress in the field of zebrafish model generation for the study of melanoma and squamous cell carcinoma (SCC), including cancer cell injection and transgenic animal development. Moreover, we will report the latest compounds and small molecules under investigation in melanoma zebrafish models.

  12. Zebrafish Embryo Toxicity Microscale Model for Ichthyotoxicity Evaluation of Marine Natural Products.

    PubMed

    Bai, Hong; Kong, Wen-Wen; Shao, Chang-Lun; Li, Yun; Liu, Yun-Zhang; Liu, Min; Guan, Fei-Fei; Wang, Chang-Yun

    2016-04-01

    Marine organisms often protect themselves against their predators by chemical defensive strategy. The second metabolites isolated from marine organisms and their symbiotic microbes have been proven to play a vital role in marine chemical ecology, such as ichthyotoxicity, allelopathy, and antifouling. It is well known that the microscale models for marine chemoecology assessment are urgently needed for trace quantity of marine natural products. Zebrafish model has been widely used as a microscale model in the fields of environment ecological evaluation and drug safety evaluation, but seldom reported for marine chemoecology assessment. In this work, zebrafish embryo toxicity microscale model was established for ichthyotoxicity evaluation of marine natural products by using 24-well microplate based on zebrafish embryo. Ichthyotoxicity was evaluated by observation of multiple toxicological endpoints, including coagulation egg, death, abnormal heartbeat, no spontaneous movement, delayed hatch, and malformation of the different organs during zebrafish embryogenesis periods at 24, 48, and 72 h post-fertilization (hpf). 3,4-Dichloroaniline was used as the positive control for method validation. Subsequently, the established model was applied to test the ichthyotoxic activity of the compounds isolated from corals and their symbiotic microbes and to isolate the bioactive secondary metabolites from the gorgonian Subergorgia mollis under bioassay guidance. It was suggested that zebrafish embryo toxicity microscale model is suitable for bioassay-guided isolation and preliminary bioactivity screening of marine natural products.

  13. Unpredictable chronic stress model in zebrafish (Danio rerio): behavioral and physiological responses.

    PubMed

    Piato, Ângelo L; Capiotti, Katiucia M; Tamborski, Angélica R; Oses, Jean P; Barcellos, Leonardo J G; Bogo, Maurício R; Lara, Diogo R; Vianna, Monica R; Bonan, Carla D

    2011-03-30

    Zebrafish (Danio rerio) have emerged as a promising model organism to study development, toxicology, pharmacology, and neuroscience, among other areas. Despite the increasing number of studies using zebrafish, behavioral studies with this species are still elementary when compared to rodents. The aim of this study was to develop a model of unpredictable chronic stress (UCS) in zebrafish. We evaluated the effects of UCS protocol during 7 or 14 days on behavioral and physiological parameters. The effects of stress were evaluated in relation to anxiety and exploratory behavior, memory, expression of corticotrophin-releasing factor (CRF) and glucocorticoid receptor (GR), and cortisol levels. As expected, UCS protocol increased the anxiety levels, impaired cognitive function, and increased CRF while decreased GR expression. Moreover, zebrafish submitted to 7 or 14 days of UCS protocol presented increased cortisol levels. The protocol developed here is a complementary model for studying the neurobiology and the effects of chronic stress in behavioral and physiological parameters. In addition, this protocol is less time consuming than standard rodent models commonly used to study chronic stress. These results confirm UCS in zebrafish as an adequate model to preclinical studies of stress, although further studies are warranted to determine its predictive validity. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Experiments on learning in zebrafish (Danio rerio): a promising model of neurocognitive function.

    PubMed

    Blaser, R E; Vira, D G

    2014-05-01

    The past decade has seen rapid proliferation of behavioral research with zebrafish, and an emergence of interest in their potential as a model of neurocognitive function. Already, zebrafish have been proposed as a model of autism, Alzheimer's, drug abuse, schizophrenia, and other disorders involving cognitive dysfunction. Zebrafish have the sophisticated sensory and motor systems necessary for complex learning experiments, and their power as a genetic and developmental model has already been established. Currently, however, learning procedures remain unrefined, and behavioral variability presents a major problem for researchers. Before zebrafish can be effectively used to study the neurological bases of learning, a set of robust and replicable techniques must be characterized and standardized. The purpose of this review is to provide an overview and critique of learning procedures that have been used with zebrafish and their results. We hope that such an analysis will prove useful in this early stage of research to guide future learning experiments and thereby improve the efficiency and validity of research with this promising new animal model.

  15. In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions.

    PubMed

    Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

    2017-01-10

    Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering.

  16. Development of an Animal Model for Alcoholic Liver Disease in Zebrafish.

    PubMed

    Lin, Jiun-Nong; Chang, Lin-Li; Lai, Chung-Hsu; Lin, Kai-Jen; Lin, Mei-Fang; Yang, Chih-Hui; Lin, Hsi-Hsun; Chen, Yen-Hsu

    2015-08-01

    Alcoholic liver disease (ALD) continues to be a major cause of liver-related morbidity and mortality worldwide. To date, no zebrafish animal model has demonstrated the characteristic manifestations of ALD in the setting of chronic alcohol exposure. The aim of this study was to develop a zebrafish animal model for ALD. Male adult zebrafish were housed in a 1% (v/v) ethanol solution up to 3 months. A histopathological study showed the characteristic features of alcoholic liver steatosis and steatohepatitis in the early stages of alcohol exposure, including fat droplet accumulation, ballooning degeneration of the hepatocytes, and Mallory body formation. As the exposure time increased, collagen deposition in the extracellular matrix was observed by Sirius red staining and immunofluorescence staining. Finally, anaplastic hepatocytes with pleomorphic nuclei were arranged in trabecular patterns and formed nodules in the zebrafish liver. Over the time course of 1% ethanol exposure, upregulations of lipogenesis, fibrosis, and tumor-related genes were also revealed by semiquantitative and quantitative real-time reverse transcription-polymerase chain reaction. As these data reflect characteristic liver damage by alcohol in humans, this zebrafish animal model may serve as a powerful tool to study the pathogenesis and treatment of ALD and its related disorders in humans.

  17. In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions

    PubMed Central

    Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

    2017-01-01

    Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering. PMID:28071731

  18. In-silico experiments of zebrafish behaviour: modeling swimming in three dimensions

    NASA Astrophysics Data System (ADS)

    Mwaffo, Violet; Butail, Sachit; Porfiri, Maurizio

    2017-01-01

    Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to reduce the number of subjects, refine experimental designs, and replace live animals. Inspired by the demonstrated advantages of computational studies in other life science domains, we establish an authentic data-driven modelling framework to simulate zebrafish swimming in three dimensions. The model encapsulates burst-and-coast swimming style, speed modulation, and wall interaction, laying the foundations for in-silico experiments of zebrafish behaviour. Through computational studies, we demonstrate the ability of the model to replicate common ethological observables such as speed and spatial preference, and anticipate experimental observations on the correlation between tank dimensions on zebrafish behaviour. Reaching to other experimental paradigms, our framework is expected to contribute to a reduction in animal use and suffering.

  19. Lysosomal localization of Japanese medaka (Oryzias latipes) Neu1 sialidase and its highly conserved enzymatic profiles with human.

    PubMed

    Ryuzono, Sena; Takase, Ryo; Oishi, Kazuki; Ikeda, Asami; Chigwechokha, Petros Kingstone; Funahashi, Aki; Komatsu, Masaharu; Miyagi, Taeko; Shiozaki, Kazuhiro

    2016-01-10

    lysosome to human. Moreover, the present study showed the possibility of medaka as a model animal of human NEU1 sialidase.

  20. Omics of the marine medaka (Oryzias melastigma) and its relevance to marine environmental research.

    PubMed

    Kim, Bo-Mi; Kim, Jaebum; Choi, Ik-Young; Raisuddin, Sheikh; Au, Doris W T; Leung, Kenneth M Y; Wu, Rudolf S S; Rhee, Jae-Sung; Lee, Jae-Seong

    2016-02-01

    In recent years, the marine medaka (Oryzias melastigma), also known as the Indian medaka or brackish medaka, has been recognized as a model fish species for ecotoxicology and environmental research in the Asian region. O. melastigma has several promising features for research, which include a short generation period (3-4 months), daily spawning, small size (3-4 cm), transparent embryos, sexual dimorphism, and ease of mass culture in the laboratory. There have been extensive transcriptome and genome studies on the marine medaka in the past decade. Such omics data can be useful in understanding the signal transduction pathways of small teleosts in response to environmental stressors. An omics-integrated approach in the study of the marine medaka is important for strengthening its role as a small fish model for marine environmental studies. In this review, we present current omics information about the marine medaka and discuss its potential applications in the study of various molecular pathways that can be targets of marine environmental stressors, such as chemical pollutants. We believe that this review will encourage the use of this small fish as a model species in marine environmental research.

  1. Novel evolutionary relationship among four fish model systems.

    PubMed

    Chen, Wei-Jen; Ortí, Guillermo; Meyer, Axel

    2004-09-01

    Knowledge of the correct phylogenetic relationships among animals is crucial for the valid interpretation of evolutionary trends in biology. Zebrafish, medaka, pufferfish and cichilds are fish models for development, genomics and comparative genetics studies, although their phylogenetic relationships have not been tested rigorously. The results of phylogenomic analysis based on 20 nuclear protein-coding genes confirmed the basal placement of zebrafish in the fish phylogeny but revealed an unexpected relationship among the other three species, contrary to traditionally held systematic views based on morphology. Our analyses show that medaka (Beloniformes) and cichlids (Perciformes) appear to be more closely related to each other than either of them is to pufferfish (Tetraodontiformes), suggesting that a re-interpretation of some findings in comparative biology might be required. In addition, phylogenomic analyses show that fish typically have more copies of nuclear genes than land vertebrates, supporting the fish-specific genome duplication hypothesis.

  2. Closantel Suppresses Angiogenesis and Cancer Growth in Zebrafish Models.

    PubMed

    Zhu, Xiao-Yu; Xia, Bo; Liu, Hong-Cui; Xu, Yi-Qiao; Huang, Chang-Jiang; Gao, Ji-Min; Dong, Qiao-Xiang; Li, Chun-Qi

    2016-04-05

    Angiogenesis has emerged as an important therapeutic target in several major diseases, including cancer and age-related macular degeneration. The zebrafish offer the potential for high-throughput drug discovery in a whole vertebrate system. In this study, we have taken advantage of the transgenic Tg (fli1a:EGFP) zebrafish line to screen the U.S. Drug Collection Library and identified 11 old drugs with antiangiogenic activity, including Closantel, an FDA-approved broad-spectrum salicylanilide antiparasitic drug for a variety of types of animals. Closantel was confirmed to have antiangiogenic activity in zebrafish with a half-inhibitory concentration (IC50) at 1.69 μM on the intersegmental vessels and 1.45 μM on the subintestinal vessels. Closantel also markedly suppressed cancer growth in zebrafish xenotransplanted with human lymphoma, cervical cancer, pancreatic cancer, and liver cancer cells, generally in a dose-dependent manner. These data reveal that Closantel has antiangiogenesis and anticancer effects and could be a potential drug candidate for animal and human cancer treatments. Further study is needed to clarify the mechanisms involved in the antiangiogenesis and anticancer effects of Closantel.

  3. Generation and Characterization of a genetic zebrafish model of SMA carrying the human SMN2 gene.

    PubMed

    Hao, Le T; Burghes, Arthur Hm; Beattie, Christine E

    2011-03-28

    Animal models of human diseases are essential as they allow analysis of the disease process at the cellular level and can advance therapeutics by serving as a tool for drug screening and target validation. Here we report the development of a complete genetic model of spinal muscular atrophy (SMA) in the vertebrate zebrafish to complement existing zebrafish, mouse, and invertebrate models and show its utility for testing compounds that alter SMN2 splicing. The human motoneuron disease SMA is caused by low levels, as opposed to a complete absence, of the survival motor neuron protein (SMN). To generate a true model of SMA in zebrafish, we have generated a transgenic zebrafish expressing the human SMN2 gene (hSMN2), which produces only a low amount of full-length SMN, and crossed this onto the smn-/- background. We show that human SMN2 is spliced in zebrafish as it is in humans and makes low levels of SMN protein. Moreover, we show that an antisense oligonucleotide that enhances correct hSMN2 splicing increases full-length hSMN RNA in this model. When we placed this transgene on the smn mutant background it rescued the neuromuscular presynaptic SV2 defect that occurs in smn mutants and increased their survival. We have generated a transgenic fish carrying the human hSMN2 gene. This gene is spliced in fish as it is in humans and mice suggesting a conserved splicing mechanism in these vertebrates. Moreover, antisense targeting of an intronic splicing silencer site increased the amount of full length SMN generated from this transgene. Having this transgene on the smn mutant fish rescued the presynaptic defect and increased survival. This model of zebrafish SMA has all of the components of human SMA and can thus be used to understand motoneuron dysfunction in SMA, can be used as an vivo test for drugs or antisense approaches that increase full-length SMN, and can be developed for drug screening.

  4. Novel use of zebrafish as a vertebrate model to screen radiation protectors and sensitizers

    SciTech Connect

    McAleer, Mary Frances . E-mail: adam.dicker@mail.tju.edu; Davidson, Christian; Davidson, William Robert; Yentzer, Brad; Farber, Steven A.; Rodeck, Ulrich; Dicker, Adam P.

    2005-01-01

    Purpose: Zebrafish (Danio rerio) embryos provide a unique vertebrate model to screen therapeutic agents easily and rapidly because of their relatively close genetic relationship to humans, ready abundance and accessibility, short embryonal development, and optical clarity. To validate zebrafish embryos as a screen for radiation modifiers, we evaluated the effects of ionizing radiation in combination with a known radioprotector (free radical scavenger Amifostine) or radiosensitizing agent (tyrosine kinase inhibitor AG1478). Methods and materials: Viable zebrafish embryos were exposed to 0-10 Gy single-fraction 250 kVp X-rays with or without either Amifostine (0-4 mM) or AG1478 (0-10 {mu}M) at defined developmental stages from 1-24 h postfertilization (hpf). Embryos were examined for morphologic abnormalities and viability until 144 hpf. Results: Radiation alone produced a time- and dose-dependent perturbation of normal embryonic development and survival with maximal sensitivity at doses {>=}4 Gy delivered before 4 hpf. Amifostine markedly attenuated this effect, whereas AG1478 enhanced teratogenicity and lethality, particularly at therapeutically relevant (2-6 Gy) radiation doses. Conclusions: Collectively, these data validate the use of zebrafish as a vertebrate model to assess the effect of radiation alone or with radiation response modulators. Zebrafish embryos may thus provide a rapid, facile system to screen novel agents ultimately intended for human use in the context of therapeutic or accidental radiation exposure.

  5. A Post-Developmental Genetic Screen for Zebrafish Models of Inherited Liver Disease

    PubMed Central

    Kim, Seok-Hyung; Wu, Shu-Yu; Baek, Jeong-In; Choi, Soo Young; Su, Yanhui; Flynn, Charles R.; Gamse, Joshua T.; Ess, Kevin C.; Hardiman, Gary; Lipschutz, Joshua H.; Abumrad, Naji N.; Rockey, Don C.

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease. PMID:25950913

  6. Zebrafish Embryo as an In Vivo Model for Behavioral and Pharmacological Characterization of Methylxanthine Drugs

    PubMed Central

    Basnet, Ram Manohar; Guarienti, Michela; Memo, Maurizio

    2017-01-01

    Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC50) calculated in zebrafish embryos and lethal doses (LD50) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds. PMID:28282918

  7. ZFIN, the Zebrafish Model Organism Database: increased support for mutants and transgenics.

    PubMed

    Howe, Douglas G; Bradford, Yvonne M; Conlin, Tom; Eagle, Anne E; Fashena, David; Frazer, Ken; Knight, Jonathan; Mani, Prita; Martin, Ryan; Moxon, Sierra A Taylor; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruef, Barbara J; Ruzicka, Leyla; Schaper, Kevin; Shao, Xiang; Singer, Amy; Sprunger, Brock; Van Slyke, Ceri E; Westerfield, Monte

    2013-01-01

    ZFIN, the Zebrafish Model Organism Database (http://zfin.org), is the central resource for zebrafish genetic, genomic, phenotypic and developmental data. ZFIN curators manually curate and integrate comprehensive data involving zebrafish genes, mutants, transgenics, phenotypes, genotypes, gene expressions, morpholinos, antibodies, anatomical structures and publications. Integrated views of these data, as well as data gathered through collaborations and data exchanges, are provided through a wide selection of web-based search forms. Among the vertebrate model organisms, zebrafish are uniquely well suited for rapid and targeted generation of mutant lines. The recent rapid production of mutants and transgenic zebrafish is making management of data associated with these resources particularly important to the research community. Here, we describe recent enhancements to ZFIN aimed at improving our support for mutant and transgenic lines, including (i) enhanced mutant/transgenic search functionality; (ii) more expressive phenotype curation methods; (iii) new downloads files and archival data access; (iv) incorporation of new data loads from laboratories undertaking large-scale generation of mutant or transgenic lines and (v) new GBrowse tracks for transgenic insertions, genes with antibodies and morpholinos.

  8. Zebrafish Embryo as an In Vivo Model for Behavioral and Pharmacological Characterization of Methylxanthine Drugs.

    PubMed

    Basnet, Ram Manohar; Guarienti, Michela; Memo, Maurizio

    2017-03-09

    Zebrafish embryo is emerging as an important tool for behavior analysis as well as toxicity testing. In this study, we compared the effect of nine different methylxanthine drugs using zebrafish embryo as a model. We performed behavioral analysis, biochemical assay and Fish Embryo Toxicity (FET) test in zebrafish embryos after treatment with methylxanthines. Each drug appeared to behave in different ways and showed a distinct pattern of results. Embryos treated with seven out of nine methylxanthines exhibited epileptic-like pattern of movements, the severity of which varied with drugs and doses used. Cyclic AMP measurement showed that, despite of a significant increase in cAMP with some compounds, it was unrelated to the observed movement behavior changes. FET test showed a different pattern of toxicity with different methylxanthines. Each drug could be distinguished from the other based on its effect on mortality, morphological defects and teratogenic effects. In addition, there was a strong positive correlation between the toxic doses (TC50) calculated in zebrafish embryos and lethal doses (LD50) in rodents obtained from TOXNET database. Taken together, all these findings elucidate the potentiality of zebrafish embryos as an in vivo model for behavioral and toxicity testing of methylxanthines and other related compounds.

  9. Limb Regeneration is Impaired in an Adult Zebrafish Model of Diabetes Mellitus

    PubMed Central

    Olsen, Ansgar S.; Sarras, Michael P.; Intine, Robert V.

    2010-01-01

    The zebrafish (Danio Rerio) is an established model organism for the study of developmental processes, human disease and tissue regeneration. We report that limb regeneration is severely impaired in our newly developed adult zebrafish model of type I diabetes. Intraperitoneal streptozocin injection of adult, wild type zebrafish results in a sustained hyperglycemic state as determined by elevated fasting blood glucose values and increased glycation of serum protein. Serum insulin levels are also decreased and pancreas immunohistochemisty revealed a lesser amount of insulin signal in hyperglycemic fish. Additionally, the diabetic complications of retinal thinning and glomerular basement membrane thickening (early signs of retinopathy and nephropathy) resulting from the hyperglycemic state were evident in streptozocin injected fish at three weeks. Most significantly, limb regeneration, following caudal fin amputation, is severely impaired in diabetic zebrafish. Nonspecific toxic effects outside the pancreas were not found to contribute to impaired limb regeneration. This experimental system using adult zebrafish facilitates a broad spectrum of genetic and molecular approaches to study regeneration in the diabetic background. PMID:20840523

  10. The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia

    PubMed Central

    Danilova, Nadia; Bibikova, Elena; Covey, Todd M.; Nathanson, David; Dimitrova, Elizabeth; Konto, Yoan; Lindgren, Anne; Glader, Bertil; Radu, Caius G.; Sakamoto, Kathleen M.; Lin, Shuo

    2014-01-01

    Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis – a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA. PMID:24812435

  11. ZFIN, the Zebrafish Model Organism Database: increased support for mutants and transgenics

    PubMed Central

    Howe, Douglas G.; Bradford, Yvonne M.; Conlin, Tom; Eagle, Anne E.; Fashena, David; Frazer, Ken; Knight, Jonathan; Mani, Prita; Martin, Ryan; Moxon, Sierra A. Taylor; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruef, Barbara J.; Ruzicka, Leyla; Schaper, Kevin; Shao, Xiang; Singer, Amy; Sprunger, Brock; Van Slyke, Ceri E.; Westerfield, Monte

    2013-01-01

    ZFIN, the Zebrafish Model Organism Database (http://zfin.org), is the central resource for zebrafish genetic, genomic, phenotypic and developmental data. ZFIN curators manually curate and integrate comprehensive data involving zebrafish genes, mutants, transgenics, phenotypes, genotypes, gene expressions, morpholinos, antibodies, anatomical structures and publications. Integrated views of these data, as well as data gathered through collaborations and data exchanges, are provided through a wide selection of web-based search forms. Among the vertebrate model organisms, zebrafish are uniquely well suited for rapid and targeted generation of mutant lines. The recent rapid production of mutants and transgenic zebrafish is making management of data associated with these resources particularly important to the research community. Here, we describe recent enhancements to ZFIN aimed at improving our support for mutant and transgenic lines, including (i) enhanced mutant/transgenic search functionality; (ii) more expressive phenotype curation methods; (iii) new downloads files and archival data access; (iv) incorporation of new data loads from laboratories undertaking large-scale generation of mutant or transgenic lines and (v) new GBrowse tracks for transgenic insertions, genes with antibodies and morpholinos. PMID:23074187

  12. A post-developmental genetic screen for zebrafish models of inherited liver disease.

    PubMed

    Kim, Seok-Hyung; Wu, Shu-Yu; Baek, Jeong-In; Choi, Soo Young; Su, Yanhui; Flynn, Charles R; Gamse, Joshua T; Ess, Kevin C; Hardiman, Gary; Lipschutz, Joshua H; Abumrad, Naji N; Rockey, Don C

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.

  13. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models.

    PubMed

    Wang, Louis W; Huttner, Inken G; Santiago, Celine F; Kesteven, Scott H; Yu, Ze-Yan; Feneley, Michael P; Fatkin, Diane

    2017-01-01

    The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l(-1) having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high frequency

  14. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models

    PubMed Central

    Wang, Louis W.; Huttner, Inken G.; Santiago, Celine F.; Kesteven, Scott H.; Yu, Ze-Yan; Feneley, Michael P.

    2017-01-01

    ABSTRACT The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l−1 having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high

  15. Dietary Strontium Increases Bone Mineral Density in Intact Zebrafish (Danio rerio): A Potential Model System for Bone Research

    PubMed Central

    Padgett-Vasquez, Steve; Garris, Heath W.; Nagy, Tim R.; D'Abramo, Louis R.; Watts, Stephen A.

    2010-01-01

    Abstract Zebrafish (Danio rerio) skeletal bone possesses properties similar to human bone, which suggests that they may be used as a model to study mineralization characteristics of the human Haversian system, as well as human bone diseases. One prerequisite for the use of zebrafish as an alternative osteoporotic bone model is to determine whether their bone displays functional plasticity similar to that observed in other bone models. Strontium citrate was supplemented into a laboratory-prepared diet (45% crude protein) to produce dietary strontium levels of 0%, 0.63%, 1.26%, 1.89%, and 2.43% and fed ad libitum twice daily for 12 weeks to 28-day-old intact zebrafish. Length was determined at 4-week intervals, and both weight and length were recorded at 12 weeks. At 12 weeks, seven zebrafish from each dietary level were analyzed for total bone mineral density by microcomputed tomography. Dietary strontium citrate supplementation significantly (p < 0.05) increased zebrafish whole-body and spinal column bone mineral density. In addition, trace amounts of strontium were incorporated into the scale matrix in those zebrafish that consumed strontium-supplemented diets. These findings suggest that zebrafish bone displays plasticity similar to that reported for other bone models (i.e., rat, mouse, and monkey) that received supplements of strontium compounds and zebrafish should be viewed as an increasingly valuable bone model. PMID:20874492

  16. Dietary strontium increases bone mineral density in intact zebrafish (Danio rerio): a potential model system for bone research.

    PubMed

    Siccardi, Anthony J; Padgett-Vasquez, Steve; Garris, Heath W; Nagy, Tim R; D'Abramo, Louis R; Watts, Stephen A

    2010-09-01

    Zebrafish (Danio rerio) skeletal bone possesses properties similar to human bone, which suggests that they may be used as a model to study mineralization characteristics of the human Haversian system, as well as human bone diseases. One prerequisite for the use of zebrafish as an alternative osteoporotic bone model is to determine whether their bone displays functional plasticity similar to that observed in other bone models. Strontium citrate was supplemented into a laboratory-prepared diet (45% crude protein) to produce dietary strontium levels of 0%, 0.63%, 1.26%, 1.89%, and 2.43% and fed ad libitum twice daily for 12 weeks to 28-day-old intact zebrafish. Length was determined at 4-week intervals, and both weight and length were recorded at 12 weeks. At 12 weeks, seven zebrafish from each dietary level were analyzed for total bone mineral density by microcomputed tomography. Dietary strontium citrate supplementation significantly (p < 0.05) increased zebrafish whole-body and spinal column bone mineral density. In addition, trace amounts of strontium were incorporated into the scale matrix in those zebrafish that consumed strontium-supplemented diets. These findings suggest that zebrafish bone displays plasticity similar to that reported for other bone models (i.e., rat, mouse, and monkey) that received supplements of strontium compounds and zebrafish should be viewed as an increasingly valuable bone model.

  17. Developmental nephrotoxicity of aristolochic acid in a zebrafish model

    SciTech Connect

    Ding, Yu-Ju; Chen, Yau-Hung

    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. Right-elevated expression of charon is regulated by fluid flow in medaka Kupffer's vesicle.

    PubMed

    Hojo, Motoki; Takashima, Shigeo; Kobayashi, Daisuke; Sumeragi, Akira; Shimada, Atsuko; Tsukahara, Tatsuya; Yokoi, Hayato; Narita, Takanori; Jindo, Tomoko; Kage, Takahiro; Kitagawa, Tadao; Kimura, Tetsuaki; Sekimizu, Koshin; Miyake, Akimitsu; Setiamarga, Davin; Murakami, Ryohei; Tsuda, Sachiko; Ooki, Shinya; Kakihara, Ken; Naruse, Kiyoshi; Takeda, Hiroyuki

    2007-06-01

    Recent studies have revealed that a cilium-generated liquid flow in the node has a crucial role in the establishment of the left-right (LR) axis in the mouse. In fish, Kupffer's vesicle (KV), a teleost-specific spherical organ attached to the tail region, is known to have an equivalent role to the mouse node during LR axis formation. However, at present, there has been no report of an asymmetric gene expressed in KV under the control of fluid flow. Here we report the earliest asymmetric gene in teleost KV, medaka charon, and its regulation. Charon is a member of the Cerberus/DAN family of proteins, first identified in zebrafish. Although zebrafish charon was reported to be symmetrically expressed in KV, medaka charon displays asymmetric expression with more intense expression on the right side. This asymmetric expression was found to be regulated by KV flow because symmetric and up-regulated charon expression was observed in flow-defective embryos with immotile cilia or disrupted KV. Taken together, medaka charon is a reliable gene marker for LR asymmetry in KV and thus, will be useful for the analysis of the early steps downstream of the fluid flow.

  19. Gene knockdown by morpholino-modified oligonucleotides in the zebrafish model: applications for developmental toxicology

    PubMed Central

    Timme-Laragy, Alicia R.; Karchner, Sibel I.; Hahn, Mark E.

    2014-01-01

    Summary The zebrafish (Danio rerio) has long been used as a model for developmental biology, making it an excellent model to use also in developmental toxicology. The many advantages of zebrafish include their small size, prolific spawning, rapid development, and transparent embryos. They can be easily manipulated genetically through the use of transgenic technology and gene knock-down via morpholino-modified antisense oligonucleotides (MOs). Knocking down specific genes to assess their role in the response to toxicant exposure provides a way to further our knowledge of how developmental toxicants work on a molecular and mechanistic level, while establishing a relationship between these molecular events and morphological, behavioral, and/or physiological effects (i.e. phenotypic anchoring). In this chapter we address important considerations for using MOs to study developmental toxicology in zebrafish embryos and provide a protocol for their use. PMID:22669659

  20. A Zebrafish Live Imaging Model Reveals Differential Responses of Microglia Toward Glioblastoma Cells In Vivo

    PubMed Central

    Hamilton, Lloyd; Astell, Katy R.; Velikova, Gergana

    2016-01-01

    Abstract Glioblastoma multiforme is the most common and deadliest form of brain cancer. Glioblastomas are infiltrated by a high number of microglia, which promote tumor growth and surrounding tissue invasion. However, it is unclear how microglia and glioma cells physically interact and if there are differences, depending on glioma cell type. Hence, we have developed a novel live imaging assay to study microglia–glioma interactions in vivo in the zebrafish brain. We transplanted well-established human glioblastoma cell lines, U87 and U251, into transgenic zebrafish lines with labelled macrophages/microglia. Our confocal live imaging results show distinct interactions between microglia and U87, as well as U251 glioblastoma cells that differ in number and nature. Importantly these interactions do not appear to be antitumoral as zebrafish microglia do not engulf and phagocytose the human glioblastoma cells. Finally, xenotransplants into the irf8−/− zebrafish mutant that lacks microglia, as well as pharmacological inhibition of the CSF-1 receptor (CSF-1R) on microglia, confirm a prominent role for zebrafish microglia in promoting human glioblastoma cell growth. This new model will be an important tool for drug screening and the development of future immunotherapeutics targeting microglia within glioma. PMID:27779463

  1. The physiology of fish at low pH: the zebrafish as a model system.

    PubMed

    Kwong, Raymond W M; Kumai, Yusuke; Perry, Steve F

    2014-03-01

    Ionic regulation and acid-base balance are fundamental to the physiology of vertebrates including fish. Acidification of freshwater ecosystems is recognized as a global environmental problem, and the physiological responses to acid exposure in a few fish species are well characterized. However, the underlying mechanisms promoting ionic and acid-base balance for most fish species that have been investigated remain unclear. Zebrafish (Danio rerio) has emerged as a powerful model system to elucidate the molecular basis of ionic and acid-base regulation. The utility of zebrafish is related to the ease with which it can be genetically manipulated, its suitability for state-of-the-art molecular and cellular approaches, and its tolerance to diverse environmental conditions. Recent studies have identified several key regulatory mechanisms enabling acclimation of zebrafish to acidic environments, including activation of the sodium/hydrogen exchanger (NHE) and H(+)-ATPase for acid secretion and Na(+) uptake, cortisol-mediated regulation of transcellular and paracellular Na(+) movements, and ionocyte proliferation controlled by specific cell-fate transcription factors. These integrated physiological responses ultimately contribute to ionic and acid-base homeostasis in zebrafish exposed to acidic water. In the present review, we provide an overview of the general effects of acid exposure on freshwater fish, the adaptive mechanisms promoting extreme acid tolerance in fishes native to acidic environments, and the mechanisms regulating ionic and acid-base balance during acid exposure in zebrafish.

  2. Proteomic analysis of the Rett syndrome experimental model mecp2(Q63X) mutant zebrafish.

    PubMed

    Cortelazzo, Alessio; Pietri, Thomas; De Felice, Claudio; Leoncini, Silvia; Guerranti, Roberto; Signorini, Cinzia; Timperio, Anna Maria; Zolla, Lello; Ciccoli, Lucia; Hayek, Joussef

    2017-02-10

    Rett syndrome (RTT) is a severe genetic disorder resulting from mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene. Recently, a zebrafish carrying a mecp2-null mutation has been developed with the resulting phenotypes exhibiting defective sensory and thigmotactic responses, and abnormal motor behavior reminiscent of the human disease. Here, we performed a proteomic analysis to examine protein expression changes in mecp2-null vs. wild-type larvae and adult zebrafish. We found a total of 20 proteins differentially expressed between wild-type and mutant zebrafish, suggesting skeletal and cardiac muscle functional defects, a stunted glycolysis and depleted energy availability. This molecular evidence is directly linked to the mecp2-null zebrafish observed phenotype. In addition, we identified changes in expression of proteins critical for a proper redox balance, suggesting an enhanced oxidative stress, a phenomenon also documented in human patients and RTT murine models. The molecular alterations observed in the mecp2-null zebrafish expand our knowledge on the molecular cascade of events that lead to the RTT phenotype.

  3. Toxic equivalency factors for halogenated aromatic hydrocarbons determined from embryotoxicity data with Japanese medaka

    SciTech Connect

    Metcalfe, C.D.; Harris, G.; Metcalfe, T.; Bennett, E.; Marshall, T.

    1995-12-31

    Toxic Equivalency Factors (TEFs) for non-ortho substituted PCBs and chlorinated diphenyl ethers have been developed from embryotoxicity data with the Japanese medaka (Oryzias latipes). The medaka TEF for non-ortho PCB congener 126 (0.1) approximates the TEF determined from mammalian experimental models, but the medaka TEFs for other non-ortho PCBs differ from mammalian TEFS. The toxicity of an extract from Lake Ontario rainbow trout to medaka embryos could not be predicted from the Toxic Equivalent Quantities (TEQs) of non-ortho PCBs, 2,3,7,8-TCDD and 2,3,7,8-TCDF in the extract. Embryotoxicity data with subtractions of the trout extract indicated that the ``non-toxic`` PCBs in complex mixtures may modify the toxicity of the non-ortho congeners. Data on the embryotoxicity of chlorinated diphenyl ethers (CDPEs) to medaka indicate that mono-ortho substituted CDPEs are more toxic than non-ortho substituted CDPEs. A fraction of extract prepared from Lake Ontario lake trout which was enriched with CDPEs was embryotoxic to medaka, which indicates that CDPEs may contribute significantly to the toxic burden of halogenated aromatic hydrocarbons in the eggs of wild fish.

  4. The State of the Art of the Zebrafish Model for Toxicology and Toxicologic Pathology Research—Advantages and Current Limitations

    PubMed Central

    Spitsbergen, Jan M.; Kent, Michael L.

    2007-01-01

    The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1–2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology. PMID:12597434

  5. Improvement of surface ECG recording in adult zebrafish reveals that the value of this model exceeds our expectation

    PubMed Central

    Liu, Chi Chi; Li, Li; Lam, Yun Wah; Siu, Chung Wah; Cheng, Shuk Han

    2016-01-01

    The adult zebrafish has been used to model the electrocardiogram (ECG) for human cardiovascular studies. Nonetheless huge variations are observed among studies probably because of the lack of a reliable and reproducible recording method. In our study, an adult zebrafish surface ECG recording technique was improved using a multi-electrode method and by pre-opening the pericardial sac. A convenient ECG data analysis method without wavelet transform was also established. Intraperitoneal injection of KCl in zebrafish induced an arrhythmia similar to that of humans, and the arrhythmia was partially rescued by calcium gluconate. Amputation and cryoinjury of the zebrafish heart induced ST segment depression and affected QRS duration after injury. Only cryoinjury decelerated the heart rate. Different changes were also observed in the QT interval during heart regeneration in these two injury models. We also characterized the electrocardiophysiology of breakdance zebrafish mutant with a prolonged QT interval, that has not been well described in previous studies. Our study provided a reliable and reproducible means to record zebrafish ECG and analyse data. The detailed characterization of the cardiac electrophysiology of zebrafish and its mutant revealed that the potential of the zebrafish in modeling the human cardiovascular system exceeds expectations. PMID:27125643

  6. Zebrafish (Danio rerio) as a model for the study of aging and exercise: physical ability and trainability decrease with age.

    PubMed

    Gilbert, Matthew J H; Zerulla, Tanja C; Tierney, Keith B

    2014-02-01

    A rapidly aging global population has motivated the development and use of models for human aging. Studies on aging have shown parallels between zebrafish and humans at the internal organization level; however, few parallels have been studied at the whole-organism level. Furthermore, the effectiveness of exercise as a method to mitigate the effects of aging has not been studied in zebrafish. We investigated the effects of aging and intermittent exercise on swimming performance, kinematics and behavior. Young, middle-aged and old zebrafish (20-29, 36-48 and 60-71% of average lifespan, respectively) were exercised to exhaustion in endurance and sprint swimming tests once a week for four weeks. Both endurance and sprint performance decreased with increased age. Swimming performance improved with exercise training in young and middle-aged zebrafish, but not in old zebrafish. Tail-beat amplitude, which is akin to stride length in humans, increased for all age groups with training. Zebrafish turning frequency, which is an indicator of routine activity, decreased with age but showed no change with exercise. In sum, our results show that zebrafish exhibit a decline in whole-organism performance and trainability with age. These findings closely resemble the senescence-related declines in physical ability experienced by humans and mammalian aging models and therefore support the use of zebrafish as a model for human exercise and aging.

  7. Zebrafish: An in vivo model for the study of neurological diseases

    PubMed Central

    Best, J D; Alderton, Wendy K

    2008-01-01

    As the population ages, there is a growing need for effective therapies for the treatment of neurological diseases. A limited number of therapeutics are currently available to improve cognitive function and research is limited by the need for in vivo models. Zebrafish have recently become a focus of neurobehavioral studies since larvae display neuropathological and behavioral phenotypes that are quantifiable and relate to those seen in man. Due to the small size of Zebrafish larvae, assays can be undertaken in 96 well plates and as the larvae can live in as little as 200 μl of fluid, only a few milligrams of compound are needed for screening. Thus in vivo analysis of the effects of compounds can be undertaken at much earlier stages in the drug discovery process. This review will look at the utility of the zebrafish in the study of neurological diseases and its role in improving the throughput of candidate compounds in in vivo screens. PMID:18830398

  8. Zebrafish model for the genetic basis of X-linked retinitis pigmentosa.

    PubMed

    Raghupathy, Rakesh Kotapati; McCulloch, Daphne L; Akhtar, Saeed; Al-mubrad, Turki M; Shu, Xinhua

    2013-03-01

    Retinitis pigmentosa (RP) affects 1/4000 individuals in most populations, and X-linked RP (XLRP) is one of the most severe forms of human retinal degeneration. Mutations in both the retinitis pigmentosa GTPase regulator (RPGR) gene and retinitis pigmentosa 2 (RP2) gene account for almost all cases of XLRP. The functional roles of both RPGR and RP2 in the pathogenesis of XLRP are unclear. Due to the surprisingly high degree of functional conservation between human genes and their zebrafish orthologues, the zebrafish has become an important model for human retinal disorders. In this brief review, we summarize the functional characterization of XLRP-causing genes, RPGR and RP2, in zebrafish, and highlight recent studies that provide insight into the cellular functions of both genes. This will not only shed light on disease mechanisms in XLRP but will also provide a solid platform to test RP-causing mutants before proposing XLRP gene therapy trials.

  9. Zebrafish: A Model for the Study of Toxicants Affecting Muscle Development and Function

    PubMed Central

    Dubińska-Magiera, Magda; Daczewska, Małgorzata; Lewicka, Anna; Migocka-Patrzałek, Marta; Niedbalska-Tarnowska, Joanna; Jagla, Krzysztof

    2016-01-01

    The rapid progress in medicine, agriculture, and allied sciences has enabled the development of a large amount of potentially useful bioactive compounds, such as drugs and pesticides. However, there is another side of this phenomenon, which includes side effects and environmental pollution. To avoid or minimize the uncontrollable consequences of using the newly developed compounds, researchers seek a quick and effective means of their evaluation. In achieving this goal, the zebrafish (Danio rerio) has proven to be a highly useful tool, mostly because of its fast growth and development, as well as the ability to absorb the molecules diluted in water through its skin and gills. In this review, we focus on the reports concerning the application of zebrafish as a model for assessing the impact of toxicants on skeletal muscles, which share many structural and functional similarities among vertebrates, including zebrafish and humans. PMID:27869769

  10. Zebrafish: A Model for the Study of Toxicants Affecting Muscle Development and Function.

    PubMed

    Dubińska-Magiera, Magda; Daczewska, Małgorzata; Lewicka, Anna; Migocka-Patrzałek, Marta; Niedbalska-Tarnowska, Joanna; Jagla, Krzysztof

    2016-11-19

    The rapid progress in medicine, agriculture, and allied sciences has enabled the development of a large amount of potentially useful bioactive compounds, such as drugs and pesticides. However, there is another side of this phenomenon, which includes side effects and environmental pollution. To avoid or minimize the uncontrollable consequences of using the newly developed compounds, researchers seek a quick and effective means of their evaluation. In achieving this goal, the zebrafish (Danio rerio) has proven to be a highly useful tool, mostly because of its fast growth and development, as well as the ability to absorb the molecules diluted in water through its skin and gills. In this review, we focus on the reports concerning the application of zebrafish as a model for assessing the impact of toxicants on skeletal muscles, which share many structural and functional similarities among vertebrates, including zebrafish and humans.

  11. The Nordic countries meeting on the zebrafish as a model for development and disease 2012.

    PubMed

    Andersson Lendahl, Monika; Zetterberg, Henrik

    2013-03-01

    The first Nordic Countries Meeting on the Zebrafish as a Model for Development and Disease took place at Karolinska Institutet in Stockholm, November 21-23, 2012. The meeting gathered 130 scientists, students, and company representatives from Iceland, Finland, Norway, Denmark, and Sweden, as well as invited guests and keynote speakers from England, Scotland, Germany, Poland, The Netherlands, Singapore, Japan, and the United States. Presentations covered a wide range of topics, including developmental biology, genetics, evolutionary biology, toxicology, behavioral studies, and disease mechanisms. The need for formal guidance and training in zebrafish housing, husbandry, and health monitoring was recognized, and the meeting expressed its support for the joint working group of the FELASA/COST action BM0804 EuFishBioMed. The decision was made to turn the Nordic meeting into an annual event and create a Nordic network of zebrafish researchers.

  12. The Nordic Countries Meeting on the Zebrafish as a Model for Development and Disease 2012

    PubMed Central

    Zetterberg, Henrik

    2013-01-01

    Abstract The first Nordic Countries Meeting on the Zebrafish as a Model for Development and Disease took place at Karolinska Institutet in Stockholm, November 21–23, 2012. The meeting gathered 130 scientists, students, and company representatives from Iceland, Finland, Norway, Denmark, and Sweden, as well as invited guests and keynote speakers from England, Scotland, Germany, Poland, The Netherlands, Singapore, Japan, and the United States. Presentations covered a wide range of topics, including developmental biology, genetics, evolutionary biology, toxicology, behavioral studies, and disease mechanisms. The need for formal guidance and training in zebrafish housing, husbandry, and health monitoring was recognized, and the meeting expressed its support for the joint working group of the FELASA/COST action BM0804 EuFishBioMed. The decision was made to turn the Nordic meeting into an annual event and create a Nordic network of zebrafish researchers. PMID:23590403

  13. Embryonic alcohol exposure: Towards the development of a zebrafish model of fetal alcohol spectrum disorders.

    PubMed

    Gerlai, Robert

    2015-11-01

    Fetal alcohol spectrum disorder (FASD) is a devastating disease of the brain caused by exposure to alcohol during prenatal development. Its prevalence exceeds 1%. The majority of FASD cases represent the milder forms of the disease which often remain undiagnosed, and even when diagnosed treatment options for the patient are limited due to lack of information about the mechanisms that underlie the disease. The zebrafish has been proposed as a model organism for exploring the mechanisms of FASD. Our laboratory has been studying the effects of low doses of alcohol during embryonic development in the zebrafish. This review discusses the methods of alcohol exposure, its effects on behavioral performance including social behavior and learning, and the potential underlying biological mechanisms in zebrafish. It is based upon a recent keynote address delivered by the author, and it focuses on findings obtained mainly in his own laboratory. It paints a promising future of this small vertebrate in FASD research. © 2015 Wiley Periodicals, Inc.

  14. Using visual lateralization to model learning and memory in zebrafish larvae

    PubMed Central

    Andersson, Madelene Åberg; Ek, Fredrik; Olsson, Roger

    2015-01-01

    Impaired learning and memory are common symptoms of neurodegenerative and neuropsychiatric diseases. Present, there are several behavioural test employed to assess cognitive functions in animal models, including the frequently used novel object recognition (NOR) test. However, although atypical functional brain lateralization has been associated with neuropsychiatric conditions, spanning from schizophrenia to autism, few animal models are available to study this phenomenon in learning and memory deficits. Here we present a visual lateralization NOR model (VLNOR) in zebrafish larvae as an assay that combines brain lateralization and NOR. In zebrafish larvae, learning and memory are generally assessed by habituation, sensitization, or conditioning paradigms, which are all representatives of nondeclarative memory. The VLNOR is the first model for zebrafish larvae that studies a memory similar to the declarative memory described for mammals. We demonstrate that VLNOR can be used to study memory formation, storage, and recall of novel objects, both short and long term, in 10-day-old zebrafish. Furthermore we show that the VLNOR model can be used to study chemical modulation of memory formation and maintenance using dizocilpine (MK-801), a frequently used non-competitive antagonist of the NMDA receptor, used to test putative antipsychotics in animal models. PMID:25727677

  15. A zebrafish transgenic model of Ewing's sarcoma reveals conserved mediators of EWS-FLI1 tumorigenesis.

    PubMed

    Leacock, Stefanie W; Basse, Audrey N; Chandler, Garvin L; Kirk, Anne M; Rakheja, Dinesh; Amatruda, James F

    2012-01-01

    Ewing's sarcoma, a malignant bone tumor of children and young adults, is a member of the small-round-blue-cell tumor family. Ewing's sarcoma family tumors (ESFTs), which include peripheral primitive neuroectodermal tumors (PNETs), are characterized by chromosomal translocations that generate fusions between the EWS gene and ETS-family transcription factors, most commonly FLI1. The EWS-FLI1 fusion oncoprotein represents an attractive therapeutic target for treatment of Ewing's sarcoma. The cell of origin of ESFT and the molecular mechanisms by which EWS-FLI1 mediates tumorigenesis remain unknown, and few animal models of Ewing's sarcoma exist. Here, we report the use of zebrafish as a vertebrate model of EWS-FLI1 function and tumorigenesis. Mosaic expression of the human EWS-FLI1 fusion protein in zebrafish caused the development of tumors with histology strongly resembling that of human Ewing's sarcoma. The incidence of tumors increased in a p53 mutant background, suggesting that the p53 pathway suppresses EWS-FLI1-driven tumorigenesis. Gene expression profiling of the zebrafish tumors defined a set of genes that might be regulated by EWS-FLI1, including the zebrafish ortholog of a crucial EWS-FLI1 target gene in humans. Stable zebrafish transgenic lines expressing EWS-FLI1 under the control of the heat-shock promoter exhibit altered embryonic development and defective convergence and extension, suggesting that EWS-FLI1 interacts with conserved developmental pathways. These results indicate that functional targets of EWS-FLI1 that mediate tumorigenesis are conserved from zebrafish to human and provide a novel context in which to study the function of this fusion oncogene.

  16. Small Fish Species as Powerful Model Systems to Study Vertebrate Physiology in Space

    NASA Astrophysics Data System (ADS)

    Aceto, J.; Muller, M.; Nourizadeh-Lillabadi, R.; Alestrom, P.; van Loon, J.; Schiller, V.; Goerlich, R.; Renn, J.; Winkler, C.

    2008-06-01

    Small fish models, mainly zebrafish (Danio rerio) and medaka (Oryzias latipes) present many advantages for studying vertebrate development and physiology. In recent years, the genome sequencing and annotation is proceeding rapidly for both species, opening the way to large-scale genome-wide analyses. Our aim is to investigate the changes induced by microgravity in small fish species by combining several whole genome approaches, with a special interest in bone related genes. We present data obtained by analyzing modulation of gene expression on a whole genome level in zebrafish exposed to two different microgravity simulation experiments or to the bonemetabolizing drug Parathyroid Hormone. Our results indicate that experimental conditions play a significant role and that a one-day exposure to clinorotation or Random Positioning Machine results in few genes regulated in common. In addition, the expression of several specific candidate genes was analyzed by quantitative RT-PCR in medaka.

  17. Zebrafish as a new model to study effects of periodontal pathogens on cardiovascular diseases

    PubMed Central

    Widziolek, Magdalena; Prajsnar, Tomasz K.; Tazzyman, Simon; Stafford, Graham P.; Potempa, Jan; Murdoch, Craig

    2016-01-01

    Porphyromonas gingivalis (Pg) is a keystone pathogen in the aetiology of chronic periodontitis. However, recent evidence suggests that the bacterium is also able to enter the bloodstream, interact with host cells and tissues, and ultimately contribute to the pathogenesis of cardiovascular disease (CVD). Here we established a novel zebrafish larvae systemic infection model showing that Pg rapidly adheres to and penetrates the zebrafish vascular endothelium causing a dose- and time-dependent mortality with associated development of pericardial oedemas and cardiac damage. The in vivo model was then used to probe the role of Pg expressed gingipain proteases using systemically delivered gingipain-deficient Pg mutants, which displayed significantly reduced zebrafish morbidity and mortality compared to wild-type bacteria. In addition, we used the zebrafish model to show efficacy of a gingipain inhibitor (KYT) on Pg-mediated systemic disease, suggesting its potential use therapeutically. Our data reveal the first real-time in vivo evidence of intracellular Pg within the endothelium of an infection model and establishes that gingipains are crucially linked to systemic disease and potentially contribute to CVD. PMID:27777406

  18. Copper toxicology, oxidative stress and inflammation using zebrafish as experimental model.

    PubMed

    Pereira, Talita Carneiro Brandão; Campos, Maria Martha; Bogo, Maurício Reis

    2016-07-01

    Copper is an essential micronutrient and a key catalytic cofactor in a wide range of enzymes. As a trace element, copper levels are tightly regulated and both its deficit and excess are deleterious to the organism. Under inflammatory conditions, serum copper levels are increased and trigger oxidative stress responses that activate inflammatory responses. Interestingly, copper dyshomeostasis, oxidative stress and inflammation are commonly present in several chronic diseases. Copper exposure can be easily modeled in zebrafish; a consolidated model in toxicology with increasing interest in immunity-related research. As a result of developmental, economical and genetic advantages, this freshwater teleost is uniquely suitable for chemical and genetic large-scale screenings, representing a powerful experimental tool for a whole-organism approach, mechanistic studies, disease modeling and beyond. Copper toxicological and more recently pro-inflammatory effects have been investigated in both larval and adult zebrafish with breakthrough findings. Here, we provide an overview of copper metabolism in health and disease and its effects on oxidative stress and inflammation responses in zebrafish models. Copper-induced inflammation is highlighted owing to its potential to easily mimic pro-oxidative and pro-inflammatory features that combined with zebrafish genetic tractability could help further in the understanding of copper metabolism, inflammatory responses and related diseases. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Evaluation of zebrafish as a model to study the pathogenesis of the opportunistic pathogen Cronobacter turicensis.

    PubMed

    Fehr, Alexander; Eshwar, Athmanya K; Neuhauss, Stephan C F; Ruetten, Maja; Lehner, Angelika; Vaughan, Lloyd

    2015-05-01

    Bacteria belonging to the genus Cronobacter spp. have been recognized as causative agents of life-threatening systemic infections, primarily in premature, low-birth weight and/or immune-compromised neonates. Knowledge remains scarce regarding the underlying molecular mechanisms of disease development. In this study, we evaluated the use of a zebrafish model to study the pathogenesis of Cronobacter turicensis LMG 23827(T), a clinical isolate responsible for two fatal sepsis cases in neonates. Here, the microinjection of approximately 50 colony forming units (CFUs) into the yolk sac resulted in the rapid multiplication of bacteria and dissemination into the blood stream at 24 h post infection (hpi), followed by the development of a severe bacteremia and larval death within 3 days. In contrast, the innate immune response of the embryos was sufficiently developed to control infection after the intravenous injection of up to 10(4) CFUs of bacteria. Infection studies using an isogenic mutant devoid of surviving and replicating in human macrophages (ΔfkpA) showed that this strain was highly attenuated in its ability to kill the larvae. In addition, the suitability of the zebrafish model system to study the effectiveness of antibiotics to treat Cronobacter infections in zebrafish embryos was examined. Our data indicate that the zebrafish model represents an excellent vertebrate model to study virulence-related aspects of this opportunistic pathogen in vivo.

  20. 3D Finite Element Electrical Model of Larval Zebrafish ECG Signals

    PubMed Central

    Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

    2016-01-01

    Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions. PMID:27824910

  1. 3D Finite Element Electrical Model of Larval Zebrafish ECG Signals.

    PubMed

    Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

    2016-01-01

    Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace's equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions.

  2. Modeling mixtures of thyroid gland function disruptors in a vertebrate alternative model, the zebrafish eleutheroembryo

    SciTech Connect

    Thienpont, Benedicte; Barata, Carlos; Raldúa, Demetrio

    2013-06-01

    Maternal thyroxine (T4) plays an essential role in fetal brain development, and even mild and transitory deficits in free-T4 in pregnant women can produce irreversible neurological effects in their offspring. Women of childbearing age are daily exposed to mixtures of chemicals disrupting the thyroid gland function (TGFDs) through the diet, drinking water, air and pharmaceuticals, which has raised the highest concern for the potential additive or synergic effects on the development of mild hypothyroxinemia during early pregnancy. Recently we demonstrated that zebrafish eleutheroembryos provide a suitable alternative model for screening chemicals impairing the thyroid hormone synthesis. The present study used the intrafollicular T4-content (IT4C) of zebrafish eleutheroembryos as integrative endpoint for testing the hypotheses that the effect of mixtures of TGFDs with a similar mode of action [inhibition of thyroid peroxidase (TPO)] was well predicted by a concentration addition concept (CA) model, whereas the response addition concept (RA) model predicted better the effect of dissimilarly acting binary mixtures of TGFDs [TPO-inhibitors and sodium-iodide symporter (NIS)-inhibitors]. However, CA model provided better prediction of joint effects than RA in five out of the six tested mixtures. The exception being the mixture MMI (TPO-inhibitor)-KClO{sub 4} (NIS-inhibitor) dosed at a fixed ratio of EC{sub 10} that provided similar CA and RA predictions and hence it was difficult to get any conclusive result. There results support the phenomenological similarity criterion stating that the concept of concentration addition could be extended to mixture constituents having common apical endpoints or common adverse outcomes. - Highlights: • Potential synergic or additive effect of mixtures of chemicals on thyroid function. • Zebrafish as alternative model for testing the effect of mixtures of goitrogens. • Concentration addition seems to predict better the effect of

  3. Stromal cell–derived factor-1 and hematopoietic cell homing in an adult zebrafish model of hematopoietic cell transplantation

    PubMed Central

    Glass, Tiffany J.; Patrinostro, Xiaobai; Tolar, Jakub; Bowman, Teresa V.; Zon, Leonard I.; Blazar, Bruce R.

    2011-01-01

    In mammals, stromal cell–derived factor-1 (SDF-1) promotes hematopoietic cell mobilization and migration. Although the zebrafish, Danio rerio, is an emerging model for studying hematopoietic cell transplantation (HCT), the role of SDF-1 in the adult zebrafish has yet to be determined. We sought to characterize sdf-1 expression and function in the adult zebrafish in the context of HCT. In situ hybridization of adult zebrafish organs shows sdf-1 expression in kidney tubules, gills, and skin. Radiation up-regulates sdf-1 expression in kidney to nearly 4-fold after 40 Gy. Assays indicate that zebrafish hematopoietic cells migrate toward sdf-1, with a migration ratio approaching 1.5 in vitro. A sdf-1a:DsRed2 transgenic zebrafish allows in vivo detection of sdf-1a expression in the adult zebrafish. Matings with transgenic reporters localized sdf-1a expression to the putative hematopoietic cell niche in proximal and distal renal tubules and collecting ducts. Importantly, transplant of hematopoietic cells into myelosuppressed recipients indicated migration of hematopoietic cells to sdf-1a–expressing sites in the kidney and skin. We conclude that sdf-1 expression and function in the adult zebrafish have important similarities to mammals, and this sdf-1 transgenic vertebrate will be useful in characterizing the hematopoietic cell niche and its interactions with hematopoietic cells. PMID:21622651

  4. Progress Towards the Development of a Fathead Minnow Embryo Test and Comparison to the Zebrafish Embryo Test for Assessing Acute Fish Toxicity

    EPA Science Inventory

    The Zebrafish Embryo Test (ZFET) for acute fish toxicity is a well developed method nearing adoption as an OECD Test Guideline. Early drafts of the test guideline (TG) envisioned a suite of potential test species to be covered including zebrafish, fathead minnow, Japanese Medaka...

  5. Progress Towards the Development of a Fathead Minnow Embryo Test and Comparison to the Zebrafish Embryo Test for Assessing Acute Fish Toxicity

    EPA Science Inventory

    The Zebrafish Embryo Test (ZFET) for acute fish toxicity is a well developed method nearing adoption as an OECD Test Guideline. Early drafts of the test guideline (TG) envisioned a suite of potential test species to be covered including zebrafish, fathead minnow, Japanese Medaka...

  6. Function Over Form: Modeling Groups of Inherited Neurological Conditions in Zebrafish

    PubMed Central

    Kozol, Robert A.; Abrams, Alexander J.; James, David M.; Buglo, Elena; Yan, Qing; Dallman, Julia E.

    2016-01-01

    Zebrafish are a unique cell to behavior model for studying the basic biology of human inherited neurological conditions. Conserved vertebrate genetics and optical transparency provide in vivo access to the developing nervous system as well as high-throughput approaches for drug screens. Here we review zebrafish modeling for two broad groups of inherited conditions that each share genetic and molecular pathways and overlap phenotypically: neurodevelopmental disorders such as Autism Spectrum Disorders (ASD), Intellectual Disability (ID) and Schizophrenia (SCZ), and neurodegenerative diseases, such as Cerebellar Ataxia (CATX), Hereditary Spastic Paraplegia (HSP) and Charcot-Marie Tooth Disease (CMT). We also conduct a small meta-analysis of zebrafish orthologs of high confidence neurodevelopmental disorder and neurodegenerative disease genes by looking at duplication rates and relative protein sizes. In the past zebrafish genetic models of these neurodevelopmental disorders and neurodegenerative diseases have provided insight into cellular, circuit and behavioral level mechanisms contributing to these conditions. Moving forward, advances in genetic manipulation, live imaging of neuronal activity and automated high-throughput molecular screening promise to help delineate the mechanistic relationships between different types of neurological conditions and accelerate discovery of therapeutic strategies. PMID:27458342

  7. Model of voluntary ethanol intake in zebrafish: effect on behavior and hypothalamic orexigenic peptides.

    PubMed

    Sterling, M E; Karatayev, O; Chang, G-Q; Algava, D B; Leibowitz, S F

    2015-02-01

    Recent studies in zebrafish have shown that exposure to ethanol in tank water affects various behaviors, including locomotion, anxiety and aggression, and produces changes in brain neurotransmitters, such as serotonin and dopamine. Building on these investigations, the present study had two goals: first, to develop a method for inducing voluntary ethanol intake in individual zebrafish, which can be used as a model in future studies to examine how this behavior is affected by various manipulations, and second, to characterize the effects of this ethanol intake on different behaviors and the expression of hypothalamic orexigenic peptides, galanin (GAL) and orexin (OX), which are known in rodents to stimulate consumption of ethanol and alter behaviors associated with alcohol abuse. Thus, we first developed a new model of voluntary intake of ethanol in fish by presenting this ethanol mixed with gelatin, which they readily consume. Using this model, we found that individual zebrafish can be trained in a short period to consume stable levels of 10% or 20% ethanol (v/v) mixed with gelatin and that their intake of this ethanol-gelatin mixture leads to pharmacologically relevant blood ethanol concentrations which are strongly, positively correlated with the amount ingested. Intake of this ethanol-gelatin mixture increased locomotion, reduced anxiety, and stimulated aggressive behavior, while increasing expression of GAL and OX in specific hypothalamic areas. These findings, confirming results in rats, provide a method in zebrafish for investigating with forward genetics and pharmacological techniques the role of different brain mechanisms in controlling ethanol intake.

  8. Function Over Form: Modeling Groups of Inherited Neurological Conditions in Zebrafish.

    PubMed

    Kozol, Robert A; Abrams, Alexander J; James, David M; Buglo, Elena; Yan, Qing; Dallman, Julia E

    2016-01-01

    Zebrafish are a unique cell to behavior model for studying the basic biology of human inherited neurological conditions. Conserved vertebrate genetics and optical transparency provide in vivo access to the developing nervous system as well as high-throughput approaches for drug screens. Here we review zebrafish modeling for two broad groups of inherited conditions that each share genetic and molecular pathways and overlap phenotypically: neurodevelopmental disorders such as Autism Spectrum Disorders (ASD), Intellectual Disability (ID) and Schizophrenia (SCZ), and neurodegenerative diseases, such as Cerebellar Ataxia (CATX), Hereditary Spastic Paraplegia (HSP) and Charcot-Marie Tooth Disease (CMT). We also conduct a small meta-analysis of zebrafish orthologs of high confidence neurodevelopmental disorder and neurodegenerative disease genes by looking at duplication rates and relative protein sizes. In the past zebrafish genetic models of these neurodevelopmental disorders and neurodegenerative diseases have provided insight into cellular, circuit and behavioral level mechanisms contributing to these conditions. Moving forward, advances in genetic manipulation, live imaging of neuronal activity and automated high-throughput molecular screening promise to help delineate the mechanistic relationships between different types of neurological conditions and accelerate discovery of therapeutic strategies.

  9. Zebrafish model of photochemical thrombosis for translational research and thrombolytic screening in vivo.

    PubMed

    Lee, I-Ju; Yang, Yi-Cyun; Hsu, Jia-Wen; Chang, Wei-Tien; Chuang, Yung-Jen; Liau, Ian

    2017-04-01

    Acute thromboembolic diseases remain the major global cause of death or disability. Although an array of thrombolytic and antithrombotic drugs has been approved to treat or prevent thromboembolic diseases, many more drugs that target specific clotting mechanisms are under development. Here a novel zebrafish model of photochemical thrombosis is reported and its prospective application for the screening and preclinical testing of thrombolytic agents in vivo is demonstrated. Through photochemical excitation, a thrombus was induced to form at a selected section of the dorsal aorta of larval zebrafish, which had been injected with photosensitizers. Such photochemical thrombosis can be consistently controlled to occlude partially or completely the targeted blood vessel. Detailed mechanistic tests indicate that the zebrafish model of photochemical thrombosis exhibits essential features of classical coagulation and a thrombolytic pathway. For demonstration, tissue plasminogen activator (tPA), a clinically feasible thrombolytic agent, was shown to effectively dissolve photochemically induced blood clots. In light of the numerous unique advantages of zebrafish as a model organism, our approach is expected to benefit not only the development of novel thrombolytic and antithrombotic strategies but also the fundamental or translational research targeting hereditary thrombotic or coagulation disorders.

  10. Assessing teratogenic changes in a zebrafish model of fetal alcohol exposure.

    PubMed

    Loucks, Evyn; Ahlgren, Sara

    2012-03-20

    Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model.

  11. Zebrafish models flex their muscles to shed light on muscular dystrophies.

    PubMed

    Berger, Joachim; Currie, Peter D

    2012-11-01

    Muscular dystrophies are a group of genetic disorders that specifically affect skeletal muscle and are characterized by progressive muscle degeneration and weakening. To develop therapies and treatments for these diseases, a better understanding of the molecular basis of muscular dystrophies is required. Thus, identification of causative genes mutated in specific disorders and the study of relevant animal models are imperative. Zebrafish genetic models of human muscle disorders often closely resemble disease pathogenesis, and the optical clarity of zebrafish embryos and larvae enables visualization of dynamic molecular processes in vivo. As an adjunct tool, morpholino studies provide insight into the molecular function of genes and allow rapid assessment of candidate genes for human muscular dystrophies. This unique set of attributes makes the zebrafish model system particularly valuable for the study of muscle diseases. This review discusses how recent research using zebrafish has shed light on the pathological basis of muscular dystrophies, with particular focus on the muscle cell membrane and the linkage between the myofibre cytoskeleton and the extracellular matrix.

  12. Role of gut microbiota in a zebrafish model with chemically induced enterocolitis involving toll-like receptor signaling pathways.

    PubMed

    He, Qi; Wang, Lin; Wang, Fan; Li, Qiurong

    2014-06-01

    It is believed that inflammatory bowel disease (IBD) involves a breakdown in interactions between the resident commensal microbiota and the host immune response. Recent studies have revealed that gut physiology and pathology relevant to human IBD can be rapidly modeled in zebrafish larvae with a number of advantages compared with murine models. The objective of this study was to evaluate the role of gut microbiota in zebrafish models with IBD-like enterocolitis. IBD-like enterocolitis was induced by exposing larval zebrafish to 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). Assays were performed using larval zebrafish collected at 8 and 10 days postfertilization (dpf ). In the absence of gut microbiota, the TNBS-induced enterocolitis was less extensive. The expression of toll-like receptor 3 (TLR3) and the TLRs signaling pathway molecules MyD88 and TRIF, the activation of NF-κB, and the production of inflammatory cytokine tumor necrosis factor-α were stimulated in TNBS-treated zebrafish but there was no corresponding alteration in germ-free fish. With microbial colonization, all results reverted to a pattern similar to that observed in conventionally reared zebrafish. We described the key role of gut microbiota in the etiology of a chemically induced larval zebrafish IBD-like model, showing an involvement of TLR signaling pathways.

  13. Wild Sex in Zebrafish: Loss of the Natural Sex Determinant in Domesticated Strains

    PubMed Central

    Wilson, Catherine A.; High, Samantha K.; McCluskey, Braedan M.; Amores, Angel; Yan, Yi-lin; Titus, Tom A.; Anderson, Jennifer L.; Batzel, Peter; Carvan, Michael J.; Schartl, Manfred; Postlethwait, John H.

    2014-01-01

    Sex determination can be robustly genetic, strongly environmental, or genetic subject to environmental perturbation. The genetic basis of sex determination is unknown for zebrafish (Danio rerio), a model for development and human health. We used RAD-tag population genomics to identify sex-linked polymorphisms. After verifying this “RAD-sex” method on medaka (Oryzias latipes), we studied two domesticated zebrafish strains (AB and TU), two natural laboratory strains (WIK and EKW), and two recent isolates from nature (NA and CB). All four natural strains had a single sex-linked region at the right tip of chromosome 4, enabling sex genotyping by PCR. Genotypes for the single nucleotide polymorphism (SNP) with the strongest statistical association to sex suggested that wild zebrafish have WZ/ZZ sex chromosomes. In natural strains, “male genotypes” became males and some “female genotypes” also became males, suggesting that the environment or genetic background can cause female-to-male sex reversal. Surprisingly, TU and AB lacked detectable sex-linked loci. Phylogenomics rooted on D. nigrofasciatus verified that all strains are monophyletic. Because AB and TU branched as a monophyletic clade, we could not rule out shared loss of the wild sex locus in a common ancestor despite their independent domestication. Mitochondrial DNA sequences showed that investigated strains represent only one of the three identified zebrafish haplogroups. Results suggest that zebrafish in nature possess a WZ/ZZ sex-determination mechanism with a major determinant lying near the right telomere of chromosome 4 that was modified during domestication. Strains providing the zebrafish reference genome lack key components of the natural sex-determination system but may have evolved variant sex-determining mechanisms during two decades in laboratory culture. PMID:25233988

  14. Zebrafish as a model system for the study of hemostasis and thrombosis

    PubMed Central

    Weyand, Angela C.; Shavit, Jordan A.

    2014-01-01

    Purpose of review Although the zebrafish has been established as a research tool over the past 2–3 decades, in hematology it has primarily been used to investigate areas distinct from coagulation. Advantages of this vertebrate model include high fecundity, rapid and external development, and conservation of virtually all clotting factors in the zebrafish genomic sequence. Here we summarize the growing application of this technology to the study of hemostasis and thrombosis. Recent findings Loss of function studies have demonstrated conservation of function for a number of zebrafish coagulation factors. These include positive and negative regulators of coagulation, as well as key components of the thrombus itself, such as von Willebrand factor, fibrinogen, and thrombocytes. Such analyses have also been leveraged to aid in the understanding of human variation and disease, as well as perform in vivo structure/function experiments. Summary The zebrafish is an organism that lends itself to a number of unique and powerful approaches not possible in mammals. This review demonstrates that there is a high degree of genetic and functional conservation of coagulation, portending future insights into hemostasis and thrombosis through use of this model. PMID:25054910

  15. New model systems to illuminate thyroid organogenesis. Part I: an update on the zebrafish toolbox.

    PubMed

    Opitz, Robert; Antonica, Francesco; Costagliola, Sabine

    2013-12-01

    Thyroid dysgenesis (TD) resulting from defects during embryonic thyroid development represents a major cause of congenital hypothyroidism. The pathogenetic mechanisms of TD in human newborns, however, are still poorly understood and disease-causing genetic variants have been identified in only a small percentage of TD cases. This limited understanding of the pathogenesis of TD is partly due to a lack of knowledge on how intrinsic factors and extrinsic signalling cues orchestrate the differentiation of thyroid follicular cells and the morphogenesis of thyroid tissue. Recently, embryonic stem cells and zebrafish embryos emerged as novel model systems that allow for innovative experimental approaches in order to decipher cellular and molecular mechanisms of thyroid development and to unravel pathogenic mechanisms of TD. Zebrafish embryos offer several salient properties for studies on thyroid organogenesis including rapid and external development, optical transparency, ease of breeding, relative short generation time and amenability for genome editing. In this review, we will highlight recent advances in the zebrafish toolkit to visualize cellular dynamics of organ development and discuss specific prospects of the zebrafish model for studies on vertebrate thyroid development and human congenital thyroid diseases.

  16. The behavioral space of zebrafish locomotion and its neural network model

    NASA Astrophysics Data System (ADS)

    Girdhar, Kiran; Benitez-Jones, Maria; Thi, Ha Pham; Nelson, Mark; Gruebele, Martin; Chemla, Yann

    2014-03-01

    How does one describe quantitatively the complex motion of vertebrates? To answer this question, we investigated a model system for vertebrate locomotion: zebrafish swimming. We performed a quantitative analysis of all stereotyped behavioral swimming patterns of zebrafish larvae: spontaneous swimming, escape response to stimulus, and prey tracking. Previous attempts to analyze zebrafish swimming motion quantitatively have imposed many arbitrary parameters. Here, we instead used a parameter-independent method that produces an orthogonal set of ``eigen-shapes'' of fish backbones to describe swimming motion in a low-dimensional space. We show that a linear combination of only three such ``eigen-shapes'' is sufficient to describe 97% of zebrafish shapes. Moreover, stereotyped swimming behaviors fall on two low-dimensional attractors embedded in this three dimensional behavioral space. We also show using a two-dimensional correlation analysis that ``scoots'' and ``R-turns,'' which were previously described as discrete behavioral states, in fact represent extrema in a continuum in this low-dimensional behavioral space. To understand the neural basis of the behavior, we have also developed a neural network model of spontaneous swimming of fish larvae. We present a set of neural parameters such as synaptic conductance, stimulus amplitude that produces swimming behavior and reconstructed the low-dimensional behavioral space obtained from experimental results.

  17. The zebrafish as a gerontology model in nervous system aging, disease, and repair.

    PubMed

    Van Houcke, Jessie; De Groef, Lies; Dekeyster, Eline; Moons, Lieve

    2015-11-01

    Considering the increasing number of elderly in the world's population today, developing effective treatments for age-related pathologies is one of the biggest challenges in modern medical research. Age-related neurodegeneration, in particular, significantly impacts important sensory, motor, and cognitive functions, seriously constraining life quality of many patients. Although our understanding of the causal mechanisms of aging has greatly improved in recent years, animal model systems still have much to tell us about this complex process. Zebrafish (Danio rerio) have gained enormous popularity for this research topic over the past decade, since their life span is relatively short but, like humans, they are still subject to gradual aging. In addition, the extensive characterization of its well-conserved molecular and cellular physiology makes the zebrafish an excellent model to unravel the underlying mechanisms of aging, disease, and repair. This review provides a comprehensive overview of the progress made in zebrafish gerontology, with special emphasis on nervous system aging. We review the evidence that classic hallmarks of aging can also be recognized within this small vertebrate, both at the molecular and cellular level. Moreover, we illustrate the high level of similarity with age-associated human pathologies through a survey of the functional deficits that arise as zebrafish age.

  18. Distribution, pharmacokinetics and primary metabolism model of tramadol in zebrafish.

    PubMed

    Zhuo, Huiqin; Jin, Hongwei; Peng, Huifang; Huang, Heqing

    2016-12-01

    The current study aimed to develop a rapid, robust and adequately sensitive method for simultaneous determination of the concentration of tramadol and its active metabolites in zebrafish. The pharmacokinetic and elimination pattern of tramadol and its major phase I metabolites following oral or intramuscular administration in zebrafish tissues was achieved using electrospray ionization‑quadrupole‑time of flight/mass spectrometry (ESI‑Q‑TOF/MS) and gas chromatography/mass spectrometry (GC‑MS). Following administration, the metabolisms were detected in the brain, eyes, muscle and gill tissues within 1 h. Two tramadol metabolites, O‑ and N‑desmethyltramadol, were detected in brain tissue, with N‑desmethyltramadol detected at a higher level. Following GC‑MS detection the curve indicated an initial rapid phase, corresponding to the detection of the tramadol within 1 min, and reached peak value in the brain at 5 min. Faster drug clearance was detected in low‑dose groups, and concentration had dropped around the to initial level (1.11 µg) at 20 min, but was detectable for up to 3 h. However, it took 80 min to fall back to the initial value (1.73 µg) in the high‑dose groups, and tramadol was detectable for up to 4 h. This study developed and validated a simple and high throughput analytical procedure to determine the distribution and pharmacokinetic profiles of tramadol, and its primary metabolites in tissues of zebrafish.

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

    PubMed Central

    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

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  2. Gene-specific differential response to anti-apoptotic therapies in zebrafish models of ocular coloboma

    PubMed Central

    Moosajee, Mariya; Shan, Xianghong; Gregory-Evans, Kevin

    2011-01-01

    Purpose We recently demonstrated that molecular therapy using aminoglycosides can overcome the underlying genetic defect in two zebrafish models of ocular coloboma and showed abnormal cell death to be a key feature associated with the optic fissure closure defects. In further studies to identify molecular therapies for this common congenital malformation, we now examine the effects of anti-apoptotic compounds in zebrafish models of ocular coloboma in vivo. Methods Two ocular coloboma zebrafish lines (pax2.1/noitu29a and lamb1/gupm189) were exposed to diferuloylmethane (curcumin) or benzyloxycarbonyl-Val-Ala-Asp(Ome)-fluoromethylketone (zVAD-fmk; a pan-caspase inhibitor) for up to 8 days post-fertilization. The effects of these compounds were assessed by morphology, histology, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and western blot analysis. Results The size of the coloboma in gup zebrafish mutants treated with diferuloylmethane was greatly reduced. In treated mutants a reduction in TUNEL staining and a 67% decrease in activated caspase-3 protein were observed. The release of cytochrome c from the mitochondria into the cytosol was reduced fourfold by in vivo diferuloylmethane treatment, suggesting that the drug was acting to inhibit the intrinsic apoptotic pathway. Inhibition of caspases directly with zVAD-fmk also resulted in a similar reduction in coloboma phenotype. Treatment with either diferuloylmethane or zVAD-fmk resulted in a statistically significant 1.4 fold increase in length of survival of these mutant zebrafish (p<0.001), which normally succumb to the lethal genetic mutation. In contrast, the coloboma phenotype in noi zebrafish mutants did not respond to either diferuloylmethane or zVAD-fmk exposure, even though inhibition of apoptotic cell death was observed by a reduction in TUNEL staining. Conclusions The differential sensitivity to anti-apoptotic agents in lamb1-deficient and pax2.1-deficient zebrafish models

  3. A larval zebrafish model of bipolar disorder as a screening platform for neuro-therapeutics.

    PubMed

    Ellis, Lee David; Soanes, Kelly Howard

    2012-08-01

    Modelling neurological diseases has proven extraordinarily difficult due to the phenotypic complexity of each disorder. The zebrafish has become a useful model system with which to study abnormal neurological and behavioural activity and holds promise as a model of human disease. While most of the disease modelling using zebrafish has made use of adults, larvae hold tremendous promise for the high-throughput screening of potential therapeutics. The further development of larval disease models will strengthen their ability to contribute to the drug screening process. Here we have used zebrafish larvae to model the symptoms of bipolar disorder by treating larvae with sub-convulsive concentrations of the GABA antagonist pentylenetetrazol (PTZ). A number of therapeutics that act on different targets, in addition to those that have been used to treat bipolar disorder, were tested against this model to assess its predictive value. Carbamazepine, valproic acid, baclofen and honokiol, were found to oppose various aspects of the PTZ-induced changes in activity. Lidocaine and haloperidol exacerbated the PTZ-induced activity changes and sulpiride had no effect. By comparing the degree of phenotypic rescue with the mechanism of action of each therapeutic we have shown that the low-concentration PTZ model can produce a number of intermediate phenotypes that model symptoms of bipolar disorder, may be useful in modelling other disease states, and will help predict the efficacy of novel therapeutics.

  4. Toxicity evaluation of biodegradable chitosan nanoparticles using a zebrafish embryo model

    PubMed Central

    Hu, Yu-Lan; Qi, Wang; Han, Feng; Shao, Jian-Zhong; Gao, Jian-Qing

    2011-01-01

    Background Although there are a number of reports regarding the toxicity evaluation of inorganic nanoparticles, knowledge on biodegradable nanomaterials, which have always been considered safe, is still limited. For example, the toxicity of chitosan nanoparticles, one of the most widely used drug/gene delivery vehicles, is largely unknown. In the present study, the zebrafish model was used for a safety evaluation of this nanocarrier. Methods Chitosan nanoparticles with two particle sizes were prepared by ionic cross-linking of chitosan with sodium tripolyphosphate. Chitosan nanoparticles of different concentrations were incubated with zebrafish embryos, and ZnO nanoparticles were used as the positive control. Results Embryo exposure to chitosan nanoparticles and ZnO nanoparticles resulted in a decreased hatching rate and increased mortality, which was concentration-dependent. Chitosan nanoparticles at a size of 200 nm caused malformations, including a bent spine, pericardial edema, and an opaque yolk in zebrafish embryos. Furthermore, embryos exposed to chitosan nanoparticles showed an increased rate of cell death, high expression of reactive oxygen species, as well as overexpression of heat shock protein 70, indicating that chitosan nanoparticles can cause physiological stress in zebrafish. The results also suggest that the toxicity of biodegradable nanocarriers such as chitosan nanoparticles must be addressed, especially considering the in vivo distribution of these nanoscaled particles. Conclusion Our results add new insights into the potential toxicity of nanoparticles produced by biodegradable materials, and may help us to understand better the nanotoxicity of drug delivery carriers. PMID:22267920

  5. Adult zebrafish as a model system for cutaneous wound-healing research.

    PubMed

    Richardson, Rebecca; Slanchev, Krasimir; Kraus, Christopher; Knyphausen, Philipp; Eming, Sabine; Hammerschmidt, Matthias

    2013-06-01

    Upon injury, the skin must quickly regenerate to regain its barrier function. In mammals, wound healing is rapid and scar free during embryogenesis, whereas in adults it involves multiple steps including blood clotting, inflammation, re-epithelialization, vascularization, and granulation tissue formation and maturation, resulting in a scar. We have established a rapid and robust method to introduce full-thickness wounds onto the flank of adult zebrafish, and show that apart from external fibrin clot formation, all steps of adult mammalian wound repair also exist in zebrafish. Wound re-epithelialization is extremely rapid and initiates with no apparent lag phase, subsequently followed by the immigration of inflammatory cells and the formation of granulation tissue, consisting of macrophages, fibroblasts, blood vessels, and collagen. The granulation tissue later regresses, resulting in minimal scar formation. Studies after chemical treatment or with transgenic fish further suggest that wound re-epithelialization occurs independently of inflammation and fibroblast growth factor signaling, whereas both are essential for fibroblast recruitment and granulation tissue formation. Together, these results demonstrate that major steps and principles of cutaneous wound healing are conserved among adult mammals and adult zebrafish, making zebrafish a valuable model for studying vertebrate skin repair.

  6. Fishing for Fetal Alcohol Spectrum Disorders: Zebrafish as a Model for Ethanol Teratogenesis.

    PubMed

    Lovely, Charles Ben; Fernandes, Yohaan; Eberhart, Johann K

    2016-10-01

    Fetal Alcohol Spectrum Disorders (FASD) describes a wide array of ethanol-induced developmental defects, including craniofacial dysmorphology and cognitive impairments. It affects ∼1 in 100 children born in the United States each year. Due to the pleiotropic effects of ethanol, animal models have proven critical in characterizing the mechanisms of ethanol teratogenesis. In this review, we focus on the utility of zebrafish in characterizing ethanol-induced developmental defects. A growing number of laboratories have focused on using zebrafish to examine ethanol-induced defects in craniofacial, cardiac, ocular, and neural development, as well as cognitive and behavioral impairments. Growing evidence supports that genetic predisposition plays a role in these ethanol-induced defects, yet little is understood about these gene-ethanol interactions. With a high degree of genetic amenability, zebrafish is at the forefront of identifying and characterizing the gene-ethanol interactions that underlie FASD. Because of the conservation of gene function between zebrafish and humans, these studies will directly translate to studies of candidate genes in human populations and allow for better diagnosis and treatment of FASD.

  7. A novel model of demyelination and remyelination in a GFP-transgenic zebrafish

    PubMed Central

    Fang, Yangwu; Lei, Xudan; Li, Xiang; Chen, Yanan; Xu, Fei; Feng, Xizeng; Wei, Shihui; Li, Yuhao

    2015-01-01

    ABSTRACT Demyelinating diseases consist of a variety of autoimmune conditions in which the myelin sheath is damaged due to genetic and/or environmental factors. During clinical treatment, some patients undergo partial remyelination, especially during the early disease stages. However, the mechanisms that regulate demyelination remain unclear. The myelin structure, myelin formation and myelin-related gene expression are highly conserved between mammals and zebrafish. Therefore, the zebrafish is an ideal model organism to study myelination. In this study, we generated a transgenic zebrafish Tg(mbp:nfsB-egfp) expressing a fusion protein composed of enhanced green fluorescent protein (EGFP) and NTR from the myelin basic protein (mbp) promoter. Tg(mbp:nfsB-egfp) expressed NTR-EGFP reproducibly and hereditarily in oligodendrocytes along the spinal cord. Treatment of zebrafish larvae Tg(mbp:nfsB-egfp) with metronidazole (Mtz) resulted in the selective ablation of oligodendrocytes and led to demyelination, accompanied by behavioral changes, including decreased total movement distance, velocity, total movement time and fast movement time. After withdrawal of Mtz for a seven day recovery period, the expression of EGFP and MBP protein was observed again which indicates remyelination. Additionally, locomotor capacity was restored. Collectively, Tg(mbp:nfsB-egfp), a heritable and stable transgenic line, provides a novel, powerful tool to study the mechanisms of demyelination and remyelination. PMID:25527642

  8. A Zebrafish Model of Myelodysplastic Syndrome Produced through tet2 Genomic Editing

    PubMed Central

    Gjini, Evisa; Mansour, Marc R.; Sander, Jeffry D.; Moritz, Nadine; Nguyen, Ashley T.; Kesarsing, Michiel; Gans, Emma; He, Shuning; Chen, Si; Ko, Myunggon; Kuang, You-Yi; Yang, Song; Zhou, Yi; Rodig, Scott; Zon, Leonard I.; Joung, J. Keith; Rao, Anjana

    2014-01-01

    The ten-eleven translocation 2 gene (TET2) encodes a member of the TET family of DNA methylcytosine oxidases that converts 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) to initiate the demethylation of DNA within genomic CpG islands. Somatic loss-of-function mutations of TET2 are frequently observed in human myelodysplastic syndrome (MDS), which is a clonal malignancy characterized by dysplastic changes of developing blood cell progenitors, leading to ineffective hematopoiesis. We used genome-editing technology to disrupt the zebrafish Tet2 catalytic domain. tet2m/m (homozygous for the mutation) zebrafish exhibited normal embryonic and larval hematopoiesis but developed progressive clonal myelodysplasia as they aged, culminating in myelodysplastic syndromes (MDS) at 24 months of age, with dysplasia of myeloid progenitor cells and anemia with abnormal circulating erythrocytes. The resultant tet2m/m mutant zebrafish lines show decreased levels of 5hmC in hematopoietic cells of the kidney marrow but not in other cell types, most likely reflecting the ability of other Tet family members to provide this enzymatic activity in nonhematopoietic tissues but not in hematopoietic cells. tet2m/m zebrafish are viable and fertile, providing an ideal model to dissect altered pathways in hematopoietic cells and, for small-molecule screens in embryos, to identify compounds with specific activity against tet2 mutant cells. PMID:25512612

  9. A tale of two models: mouse and zebrafish as complementary models for lymphatic studies.

    PubMed

    Kim, Jun-Dae; Jin, Suk-Won

    2014-07-01

    Lymphatic vessels provide essential roles in maintaining fluid homeostasis and lipid absorption. Dysfunctions of the lymphatic vessels lead to debilitating pathological conditions, collectively known as lymphedema. In addition, lymphatic vessels are a critical moderator for the onset and progression of diverse human diseases including metastatic cancer and obesity. Despite their clinical importance, there is no currently effective pharmacological therapy to regulate functions of lymphatic vessels. Recent efforts to manipulate the Vascular Endothelial Growth Factor-C (VEGFC) pathway, which is arguably the most important signaling pathway regulating lymphatic endothelial cells, to alleviate lymphedema yielded largely mixed results, necessitating identification of new targetable signaling pathways for therapeutic intervention for lymphedema. Zebrafish, a relatively new model system to investigate lymphatic biology, appears to be an ideal model to identify novel therapeutic targets for lymphatic biology. In this review, we will provide an overview of our current understanding of the lymphatic vessels in vertebrates, and discuss zebrafish as a promising in vivo model to study lymphatic vessels.

  10. A Tale of Two Models: Mouse and Zebrafish as Complementary Models for Lymphatic Studies

    PubMed Central

    Kim, Jun-Dae; Jin, Suk-Won

    2014-01-01

    Lymphatic vessels provide essential roles in maintaining fluid homeostasis and lipid absorption. Dysfunctions of the lymphatic vessels lead to debilitating pathological conditions, collectively known as lymphedema. In addition, lymphatic vessels are a critical moderator for the onset and progression of diverse human diseases including metastatic cancer and obesity. Despite their clinical importance, there is no currently effective pharmacological therapy to regulate functions of lymphatic vessels. Recent efforts to manipulate the Vascular Endothelial Growth Factor-C (VEGFC) pathway, which is arguably the most important signaling pathway regulating lymphatic endothelial cells, to alleviate lymphedema yielded largely mixed results, necessitating identification of new targetable signaling pathways for therapeutic intervention for lymphedema. Zebrafish, a relatively new model system to investigate lymphatic biology, appears to be an ideal model to identify novel therapeutic targets for lymphatic biology. In this review, we will provide an overview of our current understanding of the lymphatic vessels in vertebrates, and discuss zebrafish as a promising in vivo model to study lymphatic vessels. PMID:24854860

  11. Fasted zebrafish mimic genetic and physiological responses in mammals: a model for obesity and diabetes?

    PubMed

    Craig, Paul M; Moon, Thomas W

    2011-09-01

    With worldwide rates of obesity and type-II diabetes increasing, it is essential to identify and understand the mechanisms involved during nutrient absorption and fuel allocation. Recent studies demonstrate that nutrients (e.g., lipids and carbohydrates) play a major regulatory role in gene transcription of glycolytic and lipogenic enzymes in addition to hormones, including insulin and glucagon. These nutrients generally exert their effects through key cellular nutrient/energy receptors. Fasting was used to identify these nutrient/energy receptors known from mammalian studies to ascertain if zebrafish (Danio rerio) are a suitable model for the study of metabolic disorders. Zebrafish were subjected to a fasting/re-feeding regime for 3 weeks, and gene expression of sterol responsive binding protein 1 and 2 (SREBP), the mammalian target of rapamycin (mTOR), cAMP response element binding protein 3-like 3 (CREB3l3), and AMP-activated protein kinase alpha (AMPKα) was assessed. Fasted zebrafish lost ∼10% of their body mass over the 3-week experiment, with an associated depression in oxygen consumption. Increases in liver AMPKα and CREB3l3 mRNA transcript level were noted, concurrent with increases in the activities of the β-oxidation and gluconeogenic markers β-hydroxyacyl CoA dehydrogenase and phosphoenolpyruvate carboxykinase, respectively. Conversely, a depression in liver mTOR and SREBP1 and 2 expression was noted, with a decrease in pyruvate kinase and alanine aminotransferase activities and decreases in liver lipid and glycogen contents. Twenty-four hours after re-feeding, zebrafish rapidly recover, and the majority of parameters return to control values. Taken together, these data suggest adult zebrafish are an appropriate model for the further study of human metabolic disorders.

  12. Zebrafish teratogenicity testing.

    PubMed

    Brannen, Kimberly C; Charlap, Jeffrey H; Lewis, Elise M

    2013-01-01

    As a model for teratogenicity research, zebrafish are gaining popularity and creditability. Zebrafish embryos have been proven to be a highly valuable tool in genetics and developmental biology research and have advanced our understanding of a number of known developmental toxicants. It has yet to be determined conclusively how reliably a zebrafish embryo screening assay predicts what will happen in mammalian models, but results from initial assessments have been encouraging. Here we have presented procedures for the basic care of a zebrafish colony to support embryo production, embryo collection and culturing, and teratogenicity experiments.

  13. The common neural parasite Pseudoloma neurophilia is associated with altered startle response habituation in adult zebrafish (Danio rerio): Implications for the zebrafish as a model organism.

    PubMed

    Spagnoli, Sean; Xue, Lan; Kent, Michael L

    2015-09-15

    The zebrafish's potential as a model for human neurobehavioral research appears nearly limitless despite its relatively recent emergence as an experimental organism. Since the zebrafish has only been part of the research community for a handful of decades, pathogens from its commercial origins continue to plague laboratory stocks. One such pathogen is Pseudoloma neurophilia, a common microparasite in zebrafish laboratories world-wide that generally produces subclinical infections. Given its high prevalence, its predilection for the host's brain and spinal cord, and the delicate nature of neurobehavioral research, the behavioral consequences of subclinical P. neurophilia infection must be explored. Fish infected via cohabitation were tested for startle response habituation in parallel with controls in a device that administered ten taps over 10 min along with taps at 18 and 60 min to evaluate habituation extinction. After testing, fish were euthanized and evaluated for infection via histopathology. Infected fish had a significantly smaller reduction in startle velocity during habituation compared to uninfected tankmates and controls. Habituation was eliminated in infected and control fish at 18 min, whereas exposed negative fish retained partial habituation at 18 min. Infection was also associated with enhanced capture evasion: Despite the absence of external symptoms, infected fish tended to be caught later than uninfected fish netted from the same tank. The combination of decreased overall habituation, early extinction of habituation compared to uninfected cohorts, and enhanced netting evasion indicates that P. neurophilia infection is associated with a behavioral phenotype distinct from that of controls and uninfected cohorts. Because of its prevalence in zebrafish facilities, P. neurophilia has the potential to insidiously influence a wide range of neurobehavioral studies if these associations are causative. Rigorous health screening is therefore vital to the

  14. Transgenic zebrafish as a novel animal model to study tauopathies and other neurodegenerative disorders in vivo.

    PubMed

    Paquet, Dominik; Schmid, Bettina; Haass, Christian

    2010-01-01

    Our ageing society is confronted with a dramatic increase in patients suffering from tauopathies such as Alzheimer's disease, frontotemporal dementia and others. Typical neuropathological lesions including tangles composed of hyperphosphorylated tau protein as well as severe neuronal cell death characterize these disorders. No mechanism-based cures are available at present. Genetically modified animals are invaluable models to understand the molecular disease mechanisms and to screen for modifying compounds. We recently introduced tau-transgenic zebrafish as a novel model for tauopathies. Our model allows recapitulating key pathological features of tauopathies within an extremely short time. Moreover, life imaging of tau-dependent neuronal cell death was performed for the very first time. This demonstrated tau-dependent neuronal cell loss independent of tangle formation. Finally, we exemplified that the zebrafish frontotemporal dementia model can be used to screen for drugs that prevent abnormal tau phosphorylation and neuronal cell death.

  15. Direct gene disruption by TALENs in medaka embryos.

    PubMed

    Wang, Tiansu; Hong, Yunhan

    2014-06-10

    Targeted gene disruption (GD) is powerful for generating genetic alterations in animal genomes. Engineered endonucleases such as zinc finger nucleases and transcription activator-like effector nucleases (TALENs) allow for GD directly in animal embryos to achieve germline transmission. Here we report procedures and parameters of TALEN-mediated GD in the fish medaka by using a germ cell-specific gene dnd as a model. Embryos at the 1-cell stage were microinjected with synthetic TALEN mRNAs and examined for the survival rate and GD efficiency. Medaka embryos can tolerate a high dosage of TALEN-mRNA injection and exhibit a steadily increasing GD efficiency with increasing mRNA dosages before peaking at 100 ng/μl. This dosage produced ~24% efficiency for somatic GD. Some of the animals from manipulated embryos developed into fertile female and male. Most importantly, four fish (3 males and 1 female) examined by progeny-test were able to produce GD-bearing male and female gametes for germline transmission to F1 generation at ~10% efficiency. Therefore, TALEN is proficient for somatic and germline GD in medaka embryos, and disruption of one dnd copy does not compromise somatic development and gamete production.

  16. Germline replacement by blastula cell transplantation in the fish medaka

    PubMed Central

    Li, Mingyou; Hong, Ni; Xu, Hongyan; Song, Jianxing; Hong, Yunhan

    2016-01-01

    Primordial germ cell (PGC) specification early in development establishes the germline for reproduction and reproductive technologies. Germline replacement (GR) is a powerful tool for conservation of valuable or endangered animals. GR is achievable by germ cell transplantation into the PGC migration pathway or gonads. Blastula cell transplantation (BCT) can also lead to the chimeric germline containing PGCs of both donor and host origins. It has remained largely unknown whether BCT is able to achieve GR at a high efficiency. Here we report efficient GR by BCT into blastula embryos in the fish medaka (Oryzias latipes). Specifically, dnd depletion completely ablated host PGCs and fertility, and dnd overexpression remarkably boosted PGCs in donor blastulae. BCT between normal donor and host produced a germline transmission rate of ~4%. This rate was enhanced up to ~30% upon PGC boosting in donors. Most importantly, BCT between PGC-boosted donors and PGC-ablated hosts led to more than 90% fertility restoration and 100% GR. Therefore, BCT features an extremely high efficiency of fertility recovery and GR in medaka. This finding makes medaka an ideal model to analyze genetic and physiological donor-host compatibilities for BCT-mediated surrogate production and propagation of endangered lower vertebrates and biodiversity. PMID:27406328

  17. Zebrafish models in translational research: tipping the scales toward advancements in human health.

    PubMed

    Phillips, Jennifer B; Westerfield, Monte

    2014-07-01

    Advances in genomics and next-generation sequencing have provided clinical researchers with unprecedented opportunities to understand the molecular basis of human genetic disorders. This abundance of information places new requirements on traditional disease models, which have the potential to be used to confirm newly identified pathogenic mutations and test the efficacy of emerging therapies. The unique attributes of zebrafish are being increasingly leveraged to create functional disease models, facilitate drug discovery, and provide critical scientific bases for the development of new clinical tools for the diagnosis and treatment of human disease. In this short review and the accompanying poster, we highlight a few illustrative examples of the applications of the zebrafish model to the study of human health and disease.

  18. Computational and functional analysis of biopharmaceutical drugs in zebrafish: Erythropoietin as a test model.

    PubMed

    Guarienti, Michela; Giacopuzzi, Edoardo; Gianoncelli, Alessandra; Sigala, Sandra; Spano, Pierfranco; Pecorelli, Sergio; Pani, Luca; Memo, Maurizio

    2015-12-01

    The zebrafish (Danio rerio) is a very popular vertebrate model system, especially embryos represent a valuable tool for in vivo pharmacological assays. This is mainly due to the zebrafish advantages when compared to other animal models. Erythropoietin is a glycoprotein hormone that acts principally on erythroid progenitors, stimulating their survival, proliferation and differentiation. Recombinant human erythropoietin (rhEPO) has been widely used in medicine to treat anemia and it is one of the best-selling biotherapeutics worldwide. The recombinant molecule, industrially produced in CHO cells, has the same amino acid sequence of endogenous human erythropoietin, but differs in the glycosylation pattern. This may influence efficacy and safety, particularly immunogenicity, of the final product. We employed the zebrafish embryo as a vertebrate animal model to perform in vivo pharmacological assays. We conducted a functional analysis of rhEPO alpha Eprex(®) and two biosimilars, the erythropoietin alpha Binocrit(®) and zeta Retacrit(®). By in silico analysis and 3D modeling we proved the interaction between recombinant human erythropoietin and zebrafish endogenous erythropoietin receptor. Then we treated zebrafish embryos with the 3 rhEPOs and we investigated their effect on erythrocytes production with different assays. By real time-PCR we observed the relative upregulation of gata1 (2.4 ± 0.3 fold), embryonic α-Hb (1.9 ± 0.2 fold) and β-Hb (1.6 ± 0.1 fold) transcripts. A significant increase in Stat5 phosphorylation was also assessed in embryos treated with rhEPOs when compared with the negative controls. Live imaging in tg (kdrl:EGFP; gata1:ds-red) embryos, o-dianisidine positive area quantification and cyanomethemoglobin content quantification revealed a 1.8 ± 0.3 fold increase of erythrocytes amount in embryos treated with rhEPOs when compared with the negative controls. Finally, we verified that recombinant human erythropoietins did not cause any

  19. Adult Zebrafish (Danio rerio): An Alternative Behavioral Model of Formalin-Induced Nociception.

    PubMed

    Magalhães, Francisco Ernani Alves; de Sousa, Caio Átila Prata Bezerra; Santos, Sacha Aubrey Alves Rodrigues; Menezes, Renata Barbosa; Batista, Francisco Lucas Alves; Abreu, Ângela Oliveira; de Oliveira, Messias Vital; Moura, Luiz Francisco Wemmenson Gonçalves; Raposo, Ramon da Silva; Campos, Adriana Rolim

    2017-07-13

    The zebrafish (Danio rerio) has been proposed as a low-cost and simple alternative to the use of higher vertebrates in laboratory research on novel compounds with antinociceptive potential. In this study, we tested adult zebrafish (Danio rerio) as an alternative behavioral model of formalin-induced nociception. We evaluated the nociceptive effect of 0.1% formalin (3 or 5 μL; intramuscularly [i.m.]), applied into the tail or lips, on locomotor activity, using as parameter the number of times the fish crossed the lines between the quadrants of a glass Petri dish during the neurogenic stage (0-5 min) and the inflammatory stage (15-30 min). The behavioral model was validated by testing the antinociceptive effect of morphine and indomethacin (standard analgesic drugs used in the formalin test of rodents). We also tested whether the effect of morphine could be modulated by naloxone, an opioid antagonist. The effect of morphine and indomethacin on zebrafish locomotor behavior was evaluated with the open field test. The white/black test was used to rule out the anxiolytic effect of 0.1% formalin injected into the tail on adult zebrafish. Formalin (0.1%; 3 and 5 μL injected into the tail) increased significantly the nociceptive behavior of the adult zebrafish in both stages (p < 0.001 vs. control). Morphine and indomethacin (both 0.2 mg/mL; 20 μL; intraperitoneally [i.p.]) significantly inhibited nociception induced with formalin (5 μL injected i.m. into the tail) in both stages (p < 0.001). Naloxone blocked the antinociceptive effect of morphine. No influence on locomotion was observed. Locally administered formalin (injected into the tail) induced nociception, but not anxiety. The results suggest that the adult zebrafish behavioral model is a feasible alternative to more conventional laboratory models used in research on novel compounds with antinociceptive potential.

  20. Transforming growth factor-β signalling controls human breast cancer metastasis in a zebrafish xenograft model.

    PubMed

    Drabsch, Yvette; He, Shuning; Zhang, Long; Snaar-Jagalska, B Ewa; ten Dijke, Peter

    2013-11-07

    The transforming growth factor beta (TGF-β) signalling pathway is known to control human breast cancer invasion and metastasis. We demonstrate that the zebrafish xenograft assay is a robust and dependable animal model for examining the role of pharmacological modulators and genetic perturbation of TGF-β signalling in human breast tumour cells. We injected cancer cells into the embryonic circulation (duct of cuvier) and examined their invasion and metastasis into the avascular collagenous tail. Various aspects of the TGF-β signalling pathway were blocked by chemical inhibition, small interfering RNA (siRNA), or small hairpin RNA (shRNA). Analysis was conducted using fluorescent microscopy. Breast cancer cells with different levels of malignancy, according to in vitro and in vivo mouse studies, demonstrated invasive and metastatic properties within the embryonic zebrafish model that nicely correlated with their differential tumourigenicity in mouse models. Interestingly, MCF10A M2 and M4 cells invaded into the caudal hematopoietic tissue and were visible as a cluster of cells, whereas MDA MB 231 cells invaded into the tail fin and were visible as individual cells. Pharmacological inhibition with TGF-β receptor kinase inhibitors or tumour specific Smad4 knockdown disturbed invasion and metastasis in the zebrafish xenograft model and closely mimicked the results we obtained with these cells in a mouse metastasis model. Inhibition of matrix metallo proteinases, which are induced by TGF-β in breast cancer cells, blocked invasion and metastasis of breast cancer cells. The zebrafish-embryonic breast cancer xenograft model is applicable for the mechanistic understanding, screening and development of anti-TGF-β drugs for the treatment of metastatic breast cancer in a timely and cost-effective manner.

  1. Modeling the Behavior of Red Blood Cells within the Caudal Vein Plexus of Zebrafish.

    PubMed

    Djukic, Tijana R; Karthik, Swapna; Saveljic, Igor; Djonov, Valentin; Filipovic, Nenad

    2016-01-01

    Due to the important biological role of red blood cells (RBCs) in vertebrates, the analysis of reshaping and dynamics of RBCs motion is a critical issue in physiology and biomechanics. In this paper the behavior of RBCs within the immature capillary plexus during embryonic development of zebrafish has been analyzed. Relying on the fact that zebrafish embryos are small and optically transparent, it is possible to image the blood flow. In this way the anatomy of blood vessels is monitored along with the circulation throughout their development. Numerical simulations were performed using a specific numerical model that combines fluid flow simulation, modeling of the interaction of individual RBCs immersed in blood plasma with the surrounding fluid and modeling the deformation of individual cells. The results of numerical simulations are in accordance with the in vivo observed region of interest within the caudal vein plexus of the zebrafish embryo. Good agreement of results demonstrates the capabilities of the developed numerical model to predict and analyze the motion and deformation of RBCs in complex geometries. The proposed model (methodology) will help to elucidate different rheological and hematological related pathologies and finally to design better treatment strategies.

  2. Modeling the Behavior of Red Blood Cells within the Caudal Vein Plexus of Zebrafish

    PubMed Central

    Djukic, Tijana R.; Karthik, Swapna; Saveljic, Igor; Djonov, Valentin; Filipovic, Nenad

    2016-01-01

    Due to the important biological role of red blood cells (RBCs) in vertebrates, the analysis of reshaping and dynamics of RBCs motion is a critical issue in physiology and biomechanics. In this paper the behavior of RBCs within the immature capillary plexus during embryonic development of zebrafish has been analyzed. Relying on the fact that zebrafish embryos are small and optically transparent, it is possible to image the blood flow. In this way the anatomy of blood vessels is monitored along with the circulation throughout their development. Numerical simulations were performed using a specific numerical model that combines fluid flow simulation, modeling of the interaction of individual RBCs immersed in blood plasma with the surrounding fluid and modeling the deformation of individual cells. The results of numerical simulations are in accordance with the in vivo observed region of interest within the caudal vein plexus of the zebrafish embryo. Good agreement of results demonstrates the capabilities of the developed numerical model to predict and analyze the motion and deformation of RBCs in complex geometries. The proposed model (methodology) will help to elucidate different rheological and hematological related pathologies and finally to design better treatment strategies. PMID:27774070

  3. Zebrafish as a model for acetylcholinesterase-inhibiting organophosphorus agent exposure and oxime reactivation

    PubMed Central

    Koenig, Jeffrey A.; Dao, Thuy L.; Kan, Robert K.; Shih, Tsung-Ming

    2016-01-01

    The current research progression efforts for investigating novel treatments for exposure to organophosphorus (OP) compounds that inhibit acetylcholinesterase (AChE), including pesticides and chemical warfare nerve agents (CWNAs), rely solely on in vitro cell assays and in vivo rodent models. The zebrafish (Danio rerio) is a popular, well-established vertebrate model in biomedical research that offers high-throughput capabilities and genetic manipulation not readily available with rodents. A number of research studies have investigated the effects of subacute developmental exposure to OP pesticides in zebrafish, observing detrimental effects on gross morphology, neuronal development, and behavior. Few studies, however, have utilized this model to evaluate treatments, such as oxime reactivators, anticholinergics, or anticonvulsants, following acute exposure. Preliminary work has investigated the effects of CWNA exposure. The results clearly demonstrated relative toxicity and oxime efficacy similar to that reported for the rodent model. This review surveys the current literature utilizing zebrafish as a model for OP exposure and highlights its potential use as a high-throughput system for evaluating AChE reactivator antidotal treatments to acute pesticide and CWNA exposure. PMID:27123828

  4. Model organisms in the fight against muscular dystrophy: lessons from drosophila and Zebrafish.

    PubMed

    Plantié, Emilie; Migocka-Patrzałek, Marta; Daczewska, Małgorzata; Jagla, Krzysztof

    2015-04-09

    Muscular dystrophies (MD) are a heterogeneous group of genetic disorders that cause muscle weakness, abnormal contractions and muscle wasting, often leading to premature death. More than 30 types of MD have been described so far; those most thoroughly studied are Duchenne muscular dystrophy (DMD), myotonic dystrophy type 1 (DM1) and congenital MDs. Structurally, physiologically and biochemically, MDs affect different types of muscles and cause individual symptoms such that genetic and molecular pathways underlying their pathogenesis thus remain poorly understood. To improve our knowledge of how MD-caused muscle defects arise and to find efficacious therapeutic treatments, different animal models have been generated and applied. Among these, simple non-mammalian Drosophila and zebrafish models have proved most useful. This review discusses how zebrafish and Drosophila MD have helped to identify genetic determinants of MDs and design innovative therapeutic strategies with a special focus on DMD, DM1 and congenital MDs.

  5. Visualizing Human Hematopoietic Stem Cell Trafficking In Vivo Using a Zebrafish Xenograft Model.

    PubMed

    Staal, Frank J T; Spaink, Herman P; Fibbe, Willem E

    2016-02-15

    Zebrafish is gaining increased popularity as a model organism to study stem cell biology. It also is widely used as model system to visualize human leukemic stem cells. However, xenotransplantation of primary human stem/progenitor cells has not been described. Here, we use casper pigmentation mutant fish that are transparent crossed to fli-GFP transgenic fish as recipients of red labeled human CD34(+) cells. We have investigated various conditions and protocols with the aim to monitor and visualize the fate of transplanted human CD34(+) cells. We here report successful use of casper mutant zebrafish embryos for the direct monitoring of human hematopoietic stem cell transplantation, differentiation, and trafficking in vivo.

  6. Kainate administered to adult zebrafish causes seizures similar to those in rodent models.

    PubMed

    Alfaro, Juan M; Ripoll-Gómez, Jorge; Burgos, Javier S

    2011-04-01

    Glutamate is the major excitatory neurotransmitter of the central nervous system in vertebrates. Excitotoxicity, caused by over-stimulation of the glutamate receptors, is a major cause of neuron death in several brain diseases, including epilepsy. We describe here how behavioural seizures can be triggered in adult zebrafish by the administration of kainate and are very similar to those observed in rodent models. Kainate induced a dose-dependent sequence of behavioural changes culminating in clonus-like convulsions. Behavioural seizures were suppressed by DNQX (6,7-dinitroquinoxaline-2,3-dione) dose-dependently, whilst MK-801 (a non-competitive NMDA receptor antagonist) had a lesser effect. Kainate triggers seizures in adult zebrafish, and thus this species can be considered as a new model for studying seizures and subsequent excitotoxic brain injury. © 2011 NEURON BPh. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  7. Zebrafish as a model for understanding the evolution of the vertebrate immune system and human primary immunodeficiency.

    PubMed

    Iwanami, Norimasa

    2014-08-01

    Zebrafish is an important vertebrate model that provides the opportunity for the combination of genetic interrogation with advanced live imaging in the analysis of complex developmental and physiologic processes. Among the many advances that have been achieved using the zebrafish model, it has had a great impact on immunology. Here, I discuss recent work focusing on the genetic underpinnings of the development and function of lymphocytes in fish. Lymphocytes play critical roles in vertebrate-specific acquired immune systems of jawless and jawed fish. The unique opportunities afforded by the ability to carry out forward genetic screens and the rapidly evolving armamentarium of reverse genetics in fish usher in a new immunologic research that complements the traditional models of chicken and mouse. Recent work has greatly increased our understanding of the molecular components of the zebrafish immune system, identifying evolutionarily conserved and fish-specific functions of immune-related genes. Interestingly, some of the genes whose mutations underlie the phenotypes in immunodeficient zebrafish were also identified in immunodeficient human patients. In addition, because of the generally conserved structure and function of immune facilities, the zebrafish also provides a versatile model to examine the functional consequences of genetic variants in immune-relevant genes in the human population. Thus, I propose that genetic approaches using the zebrafish hold great potential for a better understanding of molecular mechanisms of human primary immunodeficiencies and the evolution of vertebrate immune systems. Copyright © 2014 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  8. European Zebrafish Meeting 2015 Husbandry Session Report.

    PubMed

    Varga, Zoltán M; Wilson, Carole; Alestrøm, Peter

    2016-06-01

    A workshop to address husbandry and animal welfare was held during the 9th European Zebrafish Meeting in Oslo, Norway, from June 28 to July 2, 2015. The husbandry workshop took place on Monday, June 29, and was well attended by ∼100 audience members. It highlighted problems arising from the diversity of current husbandry practices and included presentations on recent efforts to find common husbandry and animal welfare standards from a variety of international contributors, from Norway, Portugal, the United Kingdom, as well as the United States and Japan. Presentations included zebrafish and medaka as representatives of aquatic species used in biomedical research and addressed a diverse range of topics such as proposed European guidelines for zebrafish husbandry, general fish facility health and husbandry standards, cryopreservation, publication standards, and feeding strategies. The workshop highlighted the desire to develop common husbandry standards for the aquatic research community across the world.

  9. Neb: a zebrafish model of nemaline myopathy due to nebulin mutation.

    PubMed

    Telfer, William R; Nelson, Darcee D; Waugh, Trent; Brooks, Susan V; Dowling, James J

    2012-05-01

    Nemaline myopathy is one of the most common and severe non-dystrophic muscle diseases of childhood. Patients typically present in infancy with hypotonia, weakness, delayed motor development, and bulbar and respiratory difficulties. Mutations in six different genes are associated with nemaline myopathy, with nebulin mutations being the most common. No treatments or disease-modifying therapies have been identified for this disease. One of the major barriers to treatment development is the lack of models amenable to rapid and coordinated testing of potential therapeutic strategies. To overcome this barrier, we have characterized the first zebrafish model of nemaline myopathy. This model, termed neb, harbors a recessive mutation in the nebulin gene that results in decreased Nebulin protein levels, a severe motor phenotype and premature lethality. In addition to impaired motor function, neb zebrafish exhibit many of the features associated with human nemaline myopathy. These include impaired force generation, altered thin filament length and the presence of specific histopathological changes, including the formation of nemaline bodies. In summary, neb zebrafish mirror the genetic, clinical and pathological aspects of nemaline myopathy due to NEB mutation, and thus are an excellent model for future therapy development for this devastating disorder.

  10. Delineating the roles of neutrophils and macrophages in zebrafish regeneration models.

    PubMed

    Keightley, Maria-Cristina; Wang, Chieh-Huei; Pazhakh, Vahid; Lieschke, Graham J

    2014-11-01

    The outcome following injury can be healing, scarring or regeneration, all of which initiate within a resolving inflammatory response. Regeneration, comprising the complete anatomical and functional restoration of lost tissue with minimal residual consequence of injury, is the outcome that most holistically restores prior function. Leukocytes are recognized as playing an important role in determining the balance between fully regenerative or only partially reparative outcomes. Although macrophages have attracted considerable attention for their capacity to direct pro-regenerative outcomes, neutrophils are also key players in initiating inflammation and in influencing its ensuing outcome. In the context of prior studies investigating the role of neutrophils and macrophages in wound healing and in tissue/organ regeneration (mostly wound repair/healing models in mice), we comprehensively review the experimental possibilities that zebrafish models offer for delineating the individual and interactive contributions of neutrophils and macrophages to the regenerative process in embryos and adults. Zebrafish are a highly regenerative vertebrate and have a myeloid system very analogous to that of less-regenerative mammalian models. There are well-characterized reporter lines for imaging and distinguishing neutrophil and macrophage behaviors in vivo, and tools enabling selective, independent manipulation of these two leukocyte lineages for functional studies. Zebrafish are an attractive model for delineating neutrophil and macrophage contributions not only to regeneration, but also to many other pathological processes. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. A Zebrafish Larval Model to Assess Virulence of Porcine Streptococcus suis Strains

    PubMed Central

    Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M.; van Baarlen, Peter

    2016-01-01

    Streptococcus suis is an encapsulated Gram-positive bacterium, and the leading cause of sepsis and meningitis in young pigs resulting in considerable economic losses in the porcine industry. It is also considered an emerging zoonotic agent. In the environment, both avirulent and virulent strains occur in pigs, and virulent strains appear to cause disease in both humans and pigs. There is a need for a convenient, reliable and standardized animal model to assess S. suis virulence. A zebrafish (Danio rerio) larvae infection model has several advantages, including transparency of larvae, low cost, ease of use and exemption from ethical legislation up to 6 days post fertilization, but has not been previously established as a model for S. suis. Microinjection of different porcine strains of S. suis in zebrafish larvae resulted in highly reproducible dose- and strain-dependent larval death, strongly correlating with presence of the S. suis capsule and to the original virulence of the strain in pigs. Additionally we compared the virulence of the two-component system mutant of ciaRH, which is attenuated for virulence in both mice and pigs in vivo. Infection of larvae with the ΔciaRH strain resulted in significantly higher survival rate compared to infection with the S10 wild-type strain. Our data demonstrate that zebrafish larvae are a rapid and reliable model to assess the virulence of clinical porcine S. suis isolates. PMID:26999052

  12. pnp4a Is the Causal Gene of the Medaka Iridophore Mutant guanineless

    PubMed Central

    Kimura, Tetsuaki; Takehana, Yusuke; Naruse, Kiyoshi

    2017-01-01

    See-through medaka lines are suitable for observing internal organs throughout life. They were bred by crossing multiple color mutants. However, some of the causal genes for these mutants have not been identified. The medaka has four pigment cell types: black melanophores, yellow xanthophores, white leucophores, and silvery iridophores. The causal genes of melanophore, xanthophore, and leucophore mutants have been elucidated, but the causal gene for the iridophore mutant remains unknown. Here, we describe the iridophore mutant, guanineless (gu), which exhibits a strong reduction in visible iridophores throughout its larval to adult stages. The gu locus was previously mapped to chromosome 5, but was located near the telomeric region, making it difficult to integrate into the chromosome. We sought the causal gene of gu using synteny analysis with the zebrafish genome and found a strong candidate, purine nucleoside phosphorylase 4a (pnp4a). Gene targeting and complementation testing showed that pnp4a is the causal gene of gu. This result will allow the establishment of inbred medaka strains or other useful strains with see-through phenotypes without major disruption in the genetic background of each strain. PMID:28258112

  13. Direct production of XYDMY− sex reversal female medaka (Oryzias latipes) by embryo microinjection of TALENs

    PubMed Central

    Luo, Daji; Liu, Yun; Chen, Ji; Xia, Xiaoqin; Cao, Mengxi; Cheng, Bin; Wang, Xuejuan; Gong, Wuming; Qiu, Chao; Zhang, Yunsheng; Ki Cheng, Christopher Hon; Zhu, Zuoyan; Hu, Wei

    2015-01-01

    Medaka is an ideal model for sex determination and sex reversal, such as XY phenotypically female patients in humans. Here, we assembled improved TALENs targeting the DMY gene and generated XYDMY− mutants to investigate gonadal dysgenesis in medaka. DMY-TALENs resulted in indel mutations at the targeted loci (46.8%). DMY-nanos3UTR-TALENs induced mutations were passed through the germline to F1 generation with efficiencies of up to 91.7%. XYDMY− mutants developed into females, laid eggs, and stably passed the YDMY− chromosome to next generation. RNA-seq generated 157 million raw reads from WT male (WT_M_TE), WT female (WT_F_OV) and XYDMY− female medaka (TA_F_OV) gonad libraries. Differential expression analysis identified 144 up- and 293 down-regulated genes in TA_F_OV compared with WT_F_OV, 387 up- and 338 down-regulated genes in TA_F_OV compared with WT_M_TE. According to genes annotation and functional prediction, such as Wnt1 and PRCK, it revealed that incomplete ovarian function and reduced fertility of XYDMY− mutant is closely related to the wnt signaling pathway. Our results provided the transcriptional profiles of XYDMY− mutants, revealed the mechanism between sex reversal and DMY in medaka, and suggested that XYDMY− medaka was a novel mutant that is useful for investigating gonadal dysgenesis in phenotypic female patients with the 46, XY karyotype. PMID:26365677

  14. Establishment of Infection Models in Zebrafish Larvae (Danio rerio) to Study the Pathogenesis of Aeromonas hydrophila

    PubMed Central

    Saraceni, Paolo R.; Romero, Alejandro; Figueras, Antonio; Novoa, Beatriz

    2016-01-01

    Aeromonas hydrophila is a Gram-negative opportunistic pathogen of fish and terrestrial animals. In humans, A. hydrophila mainly causes gastroenteritis, septicaemia, and tissue infections. The mechanisms of infection, the main virulence factors and the host immune response triggered by A. hydrophila have been studied in detail using murine models and adult fish. However, the great limitation of studying adult animals is that the animal must be sacrificed and its tissues/organs extracted, which prevents the study of the infectious processes in the whole living animal. Zebrafish larvae are being used for the analysis of several infectious diseases, but their use for studying the pathogenesis of A. hydrophila has never been explored. The great advantage of zebrafish larvae is their transparency during the first week after fertilization, which allows detailed descriptions of the infectious processes using in vivo imaging techniques such as differential interferential contrast (DIC) and fluorescence microscopy. Moreover, the availability of fluorescent pathogens and transgenic reporter zebrafish lines expressing fluorescent immune cells, immune marker genes or cytokines/chemokines allows the host–pathogen interactions to be characterized. The present study explores the suitability of zebrafish larvae to study the pathogenesis of A. hydrophila and the interaction mechanisms between the bacterium and the innate immune responses through an infection model using different routes for infection. We used an early-embryo infection model at 3 days post-fertilization (dpf) through the microinjection of A. hydrophila into the duct of Cuvier, caudal vein, notochord, or muscle and two bath infection models using 4 dpf healthy and injured larvae. The latter resembled the natural conditions under which A. hydrophila produces infectious diseases in animals. We compared the cellular processes after infection in each anatomical site by confocal fluorescence imaging and determined the

  15. Zebrafish as a Model to Study the Role of Peroxisome Proliferating-Activated Receptors in Adipogenesis and Obesity.

    PubMed

    Den Broeder, Marjo J; Kopylova, Victoria A; Kamminga, Leonie M; Legler, Juliette

    2015-01-01

    The Peroxisome Proliferator-Activated Receptors (PPARs) PPARA and PPARD are regulators of lipid metabolism with important roles in energy release through lipid breakdown, while PPARG plays a key role in lipid storage and adipogenesis. The aim of this review is to describe the role of PPARs in lipid metabolism, adipogenesis, and obesity and evaluate the zebrafish as an emerging vertebrate model to study the function of PPARs. Zebrafish are an appropriate model to study human diseases, including obesity and related metabolic diseases, as pathways important for adipogenesis and lipid metabolism which are conserved between mammals and fish. This review synthesizes knowledge on the role of PPARs in zebrafish and focuses on the putative function of PPARs in zebrafish adipogenesis. Using in silico analysis, we confirm the presence of five PPARs (pparaa, pparab, pparda, ppardb, and pparg) in the zebrafish genome with 67-74% identity to human and mouse PPARs. During development, pparda/b paralogs and pparg show mRNA expression around the swim bladder and pancreas, the region where adipocytes first develop, whereas pparg is detectable in adipocytes at 15 days post fertilization (dpf). This review indicates that the zebrafish is a promising model to investigate the specific functions of PPARs in adipogenesis and obesity.

  16. Zebrafish as a Model to Study the Role of Peroxisome Proliferating-Activated Receptors in Adipogenesis and Obesity

    PubMed Central

    Den Broeder, Marjo J.; Kopylova, Victoria A.; Kamminga, Leonie M.; Legler, Juliette

    2015-01-01

    The Peroxisome Proliferator-Activated Receptors (PPARs) PPARA and PPARD are regulators of lipid metabolism with important roles in energy release through lipid breakdown, while PPARG plays a key role in lipid storage and adipogenesis. The aim of this review is to describe the role of PPARs in lipid metabolism, adipogenesis, and obesity and evaluate the zebrafish as an emerging vertebrate model to study the function of PPARs. Zebrafish are an appropriate model to study human diseases, including obesity and related metabolic diseases, as pathways important for adipogenesis and lipid metabolism which are conserved between mammals and fish. This review synthesizes knowledge on the role of PPARs in zebrafish and focuses on the putative function of PPARs in zebrafish adipogenesis. Using in silico analysis, we confirm the presence of five PPARs (pparaa, pparab, pparda, ppardb, and pparg) in the zebrafish genome with 67–74% identity to human and mouse PPARs. During development, pparda/b paralogs and pparg show mRNA expression around the swim bladder and pancreas, the region where adipocytes first develop, whereas pparg is detectable in adipocytes at 15 days post fertilization (dpf). This review indicates that the zebrafish is a promising model to investigate the specific functions of PPARs in adipogenesis and obesity. PMID:26697060

  17. Xmrk, kras and myc transgenic zebrafish liver cancer models share molecular signatures with subsets of human hepatocellular carcinoma.

    PubMed

    Zheng, Weiling; Li, Zhen; Nguyen, Anh Tuan; Li, Caixia; Emelyanov, Alexander; Gong, Zhiyuan

    2014-01-01

    Previously three oncogene transgenic zebrafish lines with inducible expression of xmrk, kras or Myc in the liver have been generated and these transgenic lines develop oncogene-addicted liver tumors upon chemical induction. In the current study, comparative transcriptomic approaches were used to examine the correlation of the three induced transgenic liver cancers with human liver cancers. RNA profiles from the three zebrafish tumors indicated relatively small overlaps of significantly deregulated genes and biological pathways. Nevertheless, the three transgenic tumor signatures all showed significant correlation with advanced or very advanced human hepatocellular carcinoma (HCC). Interestingly, molecular signature from each oncogene-induced zebrafish liver tumor correlated with only a small subset of human HCC samples (24-29%) and there were conserved up-regulated pathways between the zebrafish and correlated human HCC subgroup. The three zebrafish liver cancer models together represented nearly half (47.2%) of human HCCs while some human HCCs showed significant correlation with more than one signature defined from the three oncogene-addicted zebrafish tumors. In contrast, commonly deregulated genes (21 up and 16 down) in the three zebrafish tumor models generally showed accordant deregulation in the majority of human HCCs, suggesting that these genes might be more consistently deregulated in a broad range of human HCCs with different molecular mechanisms and thus serve as common diagnosis markers and therapeutic targets. Thus, these transgenic zebrafish models with well-defined oncogene-induced tumors are valuable tools for molecular classification of human HCCs and for understanding of molecular drivers in hepatocarcinogenesis in each human HCC subgroup.

  18. How mitochondrial dysfunction affects zebrafish development and cardiovascular function: an in vivo model for testing mitochondria-targeted drugs

    PubMed Central

    Pinho, Brígida R; Santos, Miguel M; Fonseca-Silva, Anabela; Valentão, Patrícia; Andrade, Paula B; Oliveira, Jorge M A

    2013-01-01

    Background and Purpose Mitochondria are a drug target in mitochondrial dysfunction diseases and in antiparasitic chemotherapy. While zebrafish is increasingly used as a biomedical model, its potential for mitochondrial research remains relatively unexplored. Here, we perform the first systematic analysis of how mitochondrial respiratory chain inhibitors affect zebrafish development and cardiovascular function, and assess multiple quinones, including ubiquinone mimetics idebenone and decylubiquinone, and the antimalarial atovaquone. Experimental Approach Zebrafish (Danio rerio) embryos were chronically and acutely exposed to mitochondrial inhibitors and quinone analogues. Concentration-response curves, developmental and cardiovascular phenotyping were performed together with sequence analysis of inhibitor-binding mitochondrial subunits in zebrafish versus mouse, human and parasites. Phenotype rescuing was assessed in co-exposure assays. Key Results Complex I and II inhibitors induced developmental abnormalities, but their submaximal toxicity was not additive, suggesting active alternative pathways for complex III feeding. Complex III inhibitors evoked a direct normal-to-dead transition. ATP synthase inhibition arrested gastrulation. Menadione induced hypochromic anaemia when transiently present following primitive erythropoiesis. Atovaquone was over 1000-fold less lethal in zebrafish than reported for Plasmodium falciparum, and its toxicity partly rescued by the ubiquinone precursor 4-hydroxybenzoate. Idebenone and decylubiquinone delayed rotenone- but not myxothiazol- or antimycin-evoked cardiac dysfunction. Conclusion and Implications This study characterizes pharmacologically induced mitochondrial dysfunction phenotypes in zebrafish, laying the foundation for comparison with future studies addressing mitochondrial dysfunction in this model organism. It has relevant implications for interpreting zebrafish disease models linked to complex I/II inhibition. Further

  19. How mitochondrial dysfunction affects zebrafish development and cardiovascular function: an in vivo model for testing mitochondria-targeted drugs.

    PubMed

    Pinho, Brígida R; Santos, Miguel M; Fonseca-Silva, Anabela; Valentão, Patrícia; Andrade, Paula B; Oliveira, Jorge M A

    2013-07-01

    Mitochondria are a drug target in mitochondrial dysfunction diseases and in antiparasitic chemotherapy. While zebrafish is increasingly used as a biomedical model, its potential for mitochondrial research remains relatively unexplored. Here, we perform the first systematic analysis of how mitochondrial respiratory chain inhibitors affect zebrafish development and cardiovascular function, and assess multiple quinones, including ubiquinone mimetics idebenone and decylubiquinone, and the antimalarial atovaquone. Zebrafish (Danio rerio) embryos were chronically and acutely exposed to mitochondrial inhibitors and quinone analogues. Concentration-response curves, developmental and cardiovascular phenotyping were performed together with sequence analysis of inhibitor-binding mitochondrial subunits in zebrafish versus mouse, human and parasites. Phenotype rescuing was assessed in co-exposure assays. Complex I and II inhibitors induced developmental abnormalities, but their submaximal toxicity was not additive, suggesting active alternative pathways for complex III feeding. Complex III inhibitors evoked a direct normal-to-dead transition. ATP synthase inhibition arrested gastrulation. Menadione induced hypochromic anaemia when transiently present following primitive erythropoiesis. Atovaquone was over 1000-fold less lethal in zebrafish than reported for Plasmodium falciparum, and its toxicity partly rescued by the ubiquinone precursor 4-hydroxybenzoate. Idebenone and decylubiquinone delayed rotenone- but not myxothiazol- or antimycin-evoked cardiac dysfunction. This study characterizes pharmacologically induced mitochondrial dysfunction phenotypes in zebrafish, laying the foundation for comparison with future studies addressing mitochondrial dysfunction in this model organism. It has relevant implications for interpreting zebrafish disease models linked to complex I/II inhibition. Further, it evidences zebrafish's potential for in vivo efficacy or toxicity screening of

  20. Xmrk, Kras and Myc Transgenic Zebrafish Liver Cancer Models Share Molecular Signatures with Subsets of Human Hepatocellular Carcinoma

    PubMed Central

    Zheng, Weiling; Li, Zhen; Nguyen, Anh Tuan; Li, Caixia; Emelyanov, Alexander; Gong, Zhiyuan

    2014-01-01

    Previously three oncogene transgenic zebrafish lines with inducible expression of xmrk, kras or Myc in the liver have been generated and these transgenic lines develop oncogene-addicted liver tumors upon chemical induction. In the current study, comparative transcriptomic approaches were used to examine the correlation of the three induced transgenic liver cancers with human liver cancers. RNA profiles from the three zebrafish tumors indicated relatively small overlaps of significantly deregulated genes and biological pathways. Nevertheless, the three transgenic tumor signatures all showed significant correlation with advanced or very advanced human hepatocellular carcinoma (HCC). Interestingly, molecular signature from each oncogene-induced zebrafish liver tumor correlated with only a small subset of human HCC samples (24–29%) and there were conserved up-regulated pathways between the zebrafish and correlated human HCC subgroup. The three zebrafish liver cancer models together represented nearly half (47.2%) of human HCCs while some human HCCs showed significant correlation with more than one signature defined from the three oncogene-addicted zebrafish tumors. In contrast, commonly deregulated genes (21 up and 16 down) in the three zebrafish tumor models generally showed accordant deregulation in the majority of human HCCs, suggesting that these genes might be more consistently deregulated in a broad range of human HCCs with different molecular mechanisms and thus serve as common diagnosis markers and therapeutic targets. Thus, these transgenic zebrafish models with well-defined oncogene-induced tumors are valuable tools for molecular classification of human HCCs and for understanding of molecular drivers in hepatocarcinogenesis in each human HCC subgroup. PMID:24633177

  1. Perspectives on Zebrafish Models of Hallucinogenic Drugs and Related Psychotropic Compounds

    PubMed Central

    2013-01-01

    Among different classes of psychotropic drugs, hallucinogenic agents exert one of the most prominent effects on human and animal behaviors, markedly altering sensory, motor, affective, and cognitive responses. The growing clinical and preclinical interest in psychedelic, dissociative, and deliriant hallucinogens necessitates novel translational, sensitive, and high-throughput in vivo models and screens. Primate and rodent models have been traditionally used to study cellular mechanisms and neural circuits of hallucinogenic drugs’ action. The utility of zebrafish (Danio rerio) in neuroscience research is rapidly growing due to their high physiological and genetic homology to humans, ease of genetic manipulation, robust behaviors, and cost effectiveness. Possessing a fully characterized genome, both adult and larval zebrafish are currently widely used for in vivo screening of various psychotropic compounds, including hallucinogens and related drugs. Recognizing the growing importance of hallucinogens in biological psychiatry, here we discuss hallucinogenic-induced phenotypes in zebrafish and evaluate their potential as efficient preclinical models of drug-induced states in humans. PMID:23883191

  2. Cancer Cell Dissemination and Homing to the Bone Marrow in a Zebrafish Model.

    PubMed

    Sacco, Antonio; Roccaro, Aldo M; Ma, Dongdong; Shi, Jiantao; Mishima, Yuji; Moschetta, Michele; Chiarini, Marco; Munshi, Nikhil; Handin, Robert I; Ghobrial, Irene M

    2016-01-15

    Advancement of many solid tumors and hematologic malignancies is frequently characterized by dissemination and homing of cancer cells to the bone marrow (BM). Methods to quantitatively characterize these key steps of the metastatic cascade in mammalian models are currently limited and do not offer opportunities to perform rapid, large-scale genomic, or drug screening. Because of their optical clarity, we used zebrafish to develop an in vivo model of cancer cell dissemination and homing to the BM. We performed intracardiac injection of multiple myeloma (MM) cells derived from human BM or cell lines and monitored their migration to the caudal hematopoietic tissue (CHT), the region where hematopoiesis occurs in the zebrafish embryo, which recapitulates a BM-like niche. Transcriptomic analyses confirmed that MM cells homing to the CHT displayed gene-expression differences compared with MM cells outside of the CHT, including significant enrichment for genes known to regulate interleukin-6 (IL6) signaling, cell adhesion, and angiogenesis. Collectively, our findings point to the zebrafish as a valuable model in which to study cancer cell homing to the hematopoietic niche and to establish a screening platform for the identification of factors and mechanisms contributing to the early steps of bone metastasis. ©2016 American Association for Cancer Research.

  3. Using zebrafish as a model to study the role of epigenetics in hearing loss.

    PubMed

    He, Yingzi; Bao, Beier; Li, Huawei

    2017-09-01

    The rapid progress of bioinformatics and high-throughput screening techniques in recent years has led to the identification of many candidate genes and small-molecule drugs that have the potential to make significant contributions to our understanding of the developmental and pathological processes of hearing, but it remains unclear how these genes and regulatory factors are coordinated. Increasing evidence suggests that epigenetic mechanisms are essential for establishing gene expression profiles and likely play an important role in the development of inner ear and in the pathology of hearing-associated diseases. Zebrafish are a valuable and tractable in vivo model organism for monitoring changes in the epigenome and for identifying new epigenetic processes and drug molecules that can influence vertebrate development. Areas covered: In this review, the authors focus on zebrafish as a model to summarize recent findings concerning the roles of epigenetics in the development, regeneration, and protection of hair cells. Expert opinion: Using the zebrafish model in combination with high-throughput screening and genome-editing technologies to investigate the function of epigenetics in hearing is crucial to help us better understand the molecular and genetic mechanisms of auditory development and function. It will also contribute to the development of new strategies to restore hearing loss.

  4. Invasiveness and metastasis of retinoblastoma in an orthotopic zebrafish tumor model.

    PubMed

    Chen, Xiaoyun; Wang, Jian; Cao, Ziquan; Hosaka, Kayoko; Jensen, Lasse; Yang, Huasheng; Sun, Yuping; Zhuang, Rujie; Liu, Yizhi; Cao, Yihai

    2015-07-14

    Retinoblastoma is a highly invasive malignant tumor that often invades the brain and metastasizes to distal organs through the blood stream. Invasiveness and metastasis of retinoblastoma can occur at the early stage of tumor development. However, an optimal preclinical model to study retinoblastoma invasiveness and metastasis in relation to drug treatment has not been developed. Here, we developed an orthotopic zebrafish model in which retinoblastoma invasion and metastasis can be monitored at a single cell level. We took the advantages of immune privilege and transparent nature of developing zebrafish embryos. Intravitreal implantation of color-coded retinoblastoma cells allowed us to kinetically monitor tumor cell invasion and metastasis. Further, interactions between retinoblastoma cells and surrounding microvasculatures were studied using a transgenic zebrafish that exhibited green fluorescent signals in blood vessels. We discovered that tumor cells invaded neighboring tissues and blood stream when primary tumors were at the microscopic sizes. These findings demonstrate that retinoblastoma metastasis occurs at the early stage and antiangiogenic drugs such as Vegf morpholino and sunitinib could potentially interfere with tumor invasiveness and metastasis. Thus, this orthotopic retinoblastoma model offers a new and unique opportunity to study the early events of tumor invasion, metastasis and drug responses.

  5. Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia

    PubMed Central

    Liu, Chao; Gates, Keith P.; Fang, Longhou; Amar, Marcelo J.; Schneider, Dina A.; Geng, Honglian; Huang, Wei; Kim, Jungsu; Pattison, Jennifer; Zhang, Jian; Witztum, Joseph L.; Remaley, Alan T.; Dong, P. Duc; Miller, Yury I.

    2015-01-01

    ABSTRACT Apolipoprotein C-II (APOC2) is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases. PMID:26044956

  6. Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia.

    PubMed

    Liu, Chao; Gates, Keith P; Fang, Longhou; Amar, Marcelo J; Schneider, Dina A; Geng, Honglian; Huang, Wei; Kim, Jungsu; Pattison, Jennifer; Zhang, Jian; Witztum, Joseph L; Remaley, Alan T; Dong, P Duc; Miller, Yury I

    2015-08-01

    Apolipoprotein C-II (APOC2) is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases. © 2015. Published by The Company of Biologists Ltd.

  7. Molecular psychiatry of zebrafish

    PubMed Central

    Stewart, Adam Michael; Ullmann, Jeremy F.P.; Norton, William H.J.; Brennan, Caroline H.; Parker, Matthew O.; Gerlai, Robert; Kalueff, Allan V.

    2014-01-01

    Due to their well-characterized neural development and high genetic homology to mammals, zebrafish (Danio rerio) have emerged as a powerful model organism in the field of biological psychiatry. Here, we discuss the molecular psychiatry of zebrafish, and its implications for translational neuroscience research and modeling CNS disorders. In particular, we outline recent genetic and technological developments allowing for in-vivo examinations, high-throughput screening and whole-brain analyses in larval and adult zebrafish. We also summarize the application of these molecular techniques to the understanding of neuropsychiatric disease, outlining the potential of zebrafish for modeling complex brain disorders, including attention-deficit/hyperactivity disorder (ADHD), aggression, post-traumatic stress and substance abuse. Critically evaluating the advantages and limitations of larval and adult fish tests, we suggest that zebrafish models become a rapidly emerging new field in modern biological psychiatry research. PMID:25349164

  8. Model of voluntary ethanol intake in zebrafish: Effect on behavior and hypothalamic orexigenic peptides

    PubMed Central

    Sterling, M.E.; Karatayev, O.; Chang, G.-Q.; Algava, D.B.; Leibowitz, S.F

    2014-01-01

    Recent studies in zebrafish have shown that exposure to ethanol in tank water affects various behaviors, including locomotion, anxiety and aggression, and produces changes in brain neurotransmitters, such as serotonin and dopamine. Building on these investigations, the present study had two goals: first, to develop a method for inducing voluntary ethanol intake in individual zebrafish, which can be used as a model in future studies to examine how this behavior is affected by various manipulations, and second, to characterize the effects of this ethanol intake on different behaviors and the expression of hypothalamic orexigenic peptides, galanin (GAL) and orexin (OX), which are known in rodents to stimulate consumption of ethanol and alter behaviors associated with alcohol abuse. Thus, we first developed a new model of voluntary intake of ethanol in fish by presenting this ethanol mixed with gelatin, which they readily consume. Using this model, we found that individual zebrafish can be trained in a short period of time to consume stable levels of 10% or 20% ethanol (v/v) mixed with gelatin and that their intake of this ethanol-gelatin mixture leads to pharmacologically-relevant blood ethanol concentrations which are strongly, positively correlated with the amount ingested. Intake of this ethanol-gelatin mixture increased locomotion, reduced anxiety, and stimulated aggressive behavior, while increasing expression of GAL and OX in specific hypothalamic areas. These findings, confirming results in rats, provide a method in zebrafish for investigating with forward genetics and pharmacological techniques the role of different brain mechanisms in controlling ethanol intake. PMID:25257106

  9. Operant models of relapse in zebrafish (Danio rerio): Resurgence, renewal, and reinstatement.

    PubMed

    Kuroda, Toshikazu; Mizutani, Yuto; Cançado, Carlos R X; Podlesnik, Christopher A

    2017-09-29

    Zebrafish are a widely used animal model in biomedical research, as an alternative to mammals, for having features such as a fully sequenced genome, high fecundity, and low-cost maintenance, but behavioral research with these fish remains scarce. The present study investigated whether zebrafish could be a new animal model for studies on the relapse of behavior (e.g., addiction and overeating) after the behavior has been extinguished. Specifically, we examined whether zebrafish would show three different types of relapse commonly studied with other species: resurgence, renewal, and reinstatement. For resurgence, a target response (i.e., approaching a sensor) was established by presenting a reinforcer (i.e., shrimp eggs) contingent upon the response in Phase 1; the target response was extinguished while introducing reinforcement for an alternative response in Phase 2; neither response produced the reinforcer in Phase 3. For renewal, a target response was established under Context A in Phase 1 and was extinguished under Context B in Phase 2; the fish were placed back in Context A in Phase 3, where extinction remained in effect. For reinstatement, a target response was established in Phase 1 and was extinguished in Phase 2; the reinforcer was presented independently of responding in Phase 3. Each type of relapse occurred in Phase 3. These results replicate and extend previous findings on relapse to a new species and suggest that zebrafish can be a useful animal model for studying the interactions of biological and environmental factors that lead to relapse. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Zebrafish as a visual and dynamic model to study the transport of nanosized drug delivery systems across the biological barriers.

    PubMed

    Li, Ye; Miao, Xiaoqing; Chen, Tongkai; Yi, Xiang; Wang, Ruibing; Zhao, Haitao; Lee, Simon Ming-Yuen; Wang, Xueqing; Zheng, Ying

    2017-08-01

    With the wide application of nanotechnology to drug delivery systems, a simple, dynamic and visual in vivo model for high-throughput screening of novel formulations with fluorescence markers across biological barriers is desperately needed. In vitro cell culture models have been widely used, although they are far from a complimentary in vivo system. Mammalian animal models are common predictive models to study transport, but they are costly and time consuming. Zebrafish (Danio rerio), a small vertebrate model, have the potential to be developed as an "intermediate" model for quick evaluations. Based on our previously established coumarin 6 nanocrystals (C6-NCs), which have two different sizes, the present study investigates the transportation of C6-NCs across four biological barriers, including the chorion, blood brain barrier (BBB), blood retinal barrier (BRB) and gastrointestinal (GI) barrier, using zebrafish embryos and larvae as in vivo models. The biodistribution and elimination of C6 from different organs were quantified in adult zebrafish. The results showed that compared to 200nm C6-NCs, 70nm C6-NCs showed better permeability across these biological barriers. A FRET study suggested that intact C6-NCs together with the free dissolved form of C6 were absorbed into the larval zebrafish. More C6 was accumulated in different organs after incubation with small sized NCs via lipid raft-mediated endocytosis in adult zebrafish, which is consistent with the findings from in vitro cell monolayers and the zebrafish larvae model. C6-NCs could be gradually eliminated in each organ over time. This study demonstrated the successful application of zebrafish as a simple and dynamic model to simultaneously assess the transport of nanosized drug delivery systems across several biological barriers and biodistribution in different organs, especially in the brain, which could be used for central nervous system (CNS) drug and delivery system screening. Copyright © 2017 Elsevier B

  11. Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model.

    PubMed

    Littleton, Robert M; Miller, Matthew; Hove, Jay R

    2012-07-23

    Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4-30 days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P < 0.05, Student's t-test). We also established that zebrafish cardiac output declines as cholesterol dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P < 0.05, 1-way ANOVA). Using this model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P < 0.05, 1-way ANOVA) and interact with cholesterol to impact cardiac output in hypercholesterolemic fish (2-way ANOVA, P < 0.05 for interaction effect). The results of this study demonstrate that the larval zebrafish has the potential to become a powerful

  12. Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model

    PubMed Central

    2012-01-01

    Background Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4–30 days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. Methods Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. Results In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P < 0.05, Student’s t-test). We also established that zebrafish cardiac output declines as cholesterol dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P < 0.05, 1-way ANOVA). Using this model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P < 0.05, 1-way ANOVA) and interact with cholesterol to impact cardiac output in hypercholesterolemic fish (2-way ANOVA, P < 0.05 for interaction effect). Conclusions The results of this study demonstrate

  13. Zebrafish models of idiopathic scoliosis link cerebrospinal fluid flow defects to spine curvature.

    PubMed

    Grimes, D T; Boswell, C W; Morante, N F C; Henkelman, R M; Burdine, R D; Ciruna, B

    2016-06-10

    Idiopathic scoliosis (IS) affects 3% of children worldwide, yet the mechanisms underlying this spinal deformity remain unknown. Here we show that ptk7 mutant zebrafish, a faithful developmental model of IS, exhibit defects in ependymal cell cilia development and cerebrospinal fluid (CSF) flow. Transgenic reintroduction of Ptk7 in motile ciliated lineages prevents scoliosis in ptk7 mutants, and mutation of multiple independent cilia motility genes yields IS phenotypes. We define a finite developmental window for motile cilia in zebrafish spine morphogenesis. Notably, restoration of cilia motility after the onset of scoliosis blocks spinal curve progression. Together, our results indicate a critical role for cilia-driven CSF flow in spine development, implicate irregularities in CSF flow as an underlying biological cause of IS, and suggest that noninvasive therapeutic intervention may prevent severe scoliosis.

  14. Use of TSHβ:EGFP transgenic zebrafish as a rapid in vivo model for assessing thyroid-disrupting chemicals

    SciTech Connect

    Ji, Cheng; Jin, Xia; He, Jiangyan; Yin, Zhan

    2012-07-15

    Accumulating evidence indicates that a wide range of chemicals have the ability to interfere with the hypothalamic–pituitary–thyroid (HPT) axis. Novel endpoints should be evaluated in addition to existing methods in order to effectively assess the effects of these chemicals on the HPT axis. Thyroid-stimulating hormone subunit β (TSHβ) plays central regulatory roles in the HPT system. We identified the regulatory region that determines the expression level of zebrafish TSHβ in the anterior pituitary. In the transgenic zebrafish with EGFP driven by the TSHβ promoter, the similar responsive patterns between the expression levels of TSHβ:EGFP and endogenous TSHβ mRNA in the pituitary are observed following treatments with goitrogen chemicals and exogenous thyroid hormones (THs). These results suggest that the TSHβ:EGFP transgenic reporter zebrafish may be a useful alternative in vivo model for the assessment of chemicals interfering with the HPT system. Highlights: ► The promoter of zebrafish TSHβ gene has been identified. ► The stable TSHβ:EGFP transgenic zebrafish reporter germline has been generated. ► The EGFP in the transgenic fish recapitulated the pattern of pituitary TSHβ mRNA. ► The transgenic zebrafish may be an in vivo model for EDC assessment.

  15. Embryonic fate map of first pharyngeal arch structures in the sox10: kaede zebrafish transgenic model.

    PubMed

    Dougherty, Max; Kamel, George; Shubinets, Valeriy; Hickey, Graham; Grimaldi, Michael; Liao, Eric C

    2012-09-01

    Cranial neural crest cells follow stereotypic patterns of migration to form craniofacial structures. The zebrafish is a powerful vertebrate genetic model where transgenics with reporter proteins under the transcriptional regulation of lineage-specific promoters can be generated. Numerous studies demonstrate that the zebrafish ethmoid plate is embryologically analogous to the mammalian palate. A fate map correlating embryonic cranial neural crest to defined jaw structures would provide a useful context for the morphogenetic analysis of craniofacial development. To that end, the sox10:kaede transgenic was generated, where sox10 provides lineage restriction to the neural crest. Specific regions of neural crest were labeled at the 10-somite stage by photoconversion of the kaede reporter protein. Lineage analysis was carried out during pharyngeal development in wild-type animals, after miR140 injection, and after estradiol treatment. At the 10-somite stage, cranial neural crest cells anterior of the eye contributed to the median ethmoid plate, whereas cells medial to the eye formed the lateral ethmoid plate and trabeculae and a posterior population formed the mandible. miR-140 overexpression and estradiol inhibition of Hedgehog signaling resulted in cleft development, with failed migration of the anterior cell population to form the median ethmoid plate. The sox10:kaede transgenic line provides a useful tool for neural crest lineage analysis. These studies illustrate the advantages of the zebrafish model for application in morphogenetic studies of vertebrate craniofacial development.

  16. Polyclonal anti-Candida antibody improves phagocytosis and overall outcome in zebrafish model of disseminated candidiasis.

    PubMed

    Bergeron, Audrey C; Barker, Sarah E; Brothers, Kimberly M; Prasad, Brinda C; Wheeler, Robert T

    2017-03-01

    Fungal infections are a major cause of animal and plant morbidity and mortality worldwide. Effective biological therapeutics could complement current antifungal drugs, but understanding of their in vivo mechanisms has been hampered by technical barriers to intravital imaging of host-pathogen interactions. Here we characterize the fungal infection of zebrafish as a model to understand the mechanism-of-action for biological antifungal therapeutics through intravital imaging of these transparent animals. We find that non-specific human IgG enhances phagocytosis by zebrafish phagocytes in vivo. Polyclonal anti-Candida antibodies enhance containment of fungi in vivo and promote survival. Analysis suggests that early phagocytic containment is a strong prognostic indicator for overall survival. Although polyclonal anti-Candida antibodies protect against disease, this is not necessarily the case for individual monoclonal anti-Candida antibodies. Thus, the zebrafish appears to provide a useful model host for testing if a biological therapeutic promotes phagocytosis in vivo and enhances protection against candidemia.

  17. Zebrafish as a Model to Assess the Teratogenic Potential of Nitrite.

    PubMed

    Keshari, Vishal; Adeeb, Basma; Simmons, Alison E; Simmons, Thomas W; Diep, Cuong Q

    2016-02-16

    High nitrate levels in the environment may result in congenital defects or miscarriages in humans. Presumably, this is due to the conversion of nitrate to nitrite by gut and salivary bacteria. However, in other mammalian studies, high nitrite levels do not cause birth defects, although they can lead to poor reproductive outcomes. Thus, the teratogenic potential of nitrite is not clear. It would be useful to have a vertebrate model system to easily assess teratogenic effects of nitrite or any other chemical of interest. Here, we demonstrate the utility of zebrafish (Danio rerio) to screen compounds for toxicity and embryonic defects. Zebrafish embryos are fertilized externally and have rapid development, making them a good model for teratogenic studies. We show that increasing the time of exposure to nitrite negatively affects survival. Increasing the concentration of nitrite also adversely affects survival, whereas nitrate does not. For embryos that survive nitrite exposure, various defects can occur, including pericardial and yolk sac edema, swim bladder noninflation, and craniofacial malformation. Our results indicate that the zebrafish is a convenient system for studying the teratogenic potential of nitrite. This approach can easily be adapted to test other chemicals for their effects on early vertebrate development.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Behavioral and synaptic circuit features in a zebrafish model of fragile X syndrome.

    PubMed

    Ng, Ming-Chong; Yang, Yi-Ling; Lu, Kwok-Tung

    2013-01-01

    Fragile X syndrome (FXS) is the most frequent inherited form of human mental retardation. It is characterized by cognitive impairment and physical and behavioral problems and is caused by the silencing of fmr1 transcription and the absence of the fmr1 protein (FMRP). Recently, animal models of FXS have greatly facilitated the investigation of the molecular and cellular mechanisms of this loss-of-function disorder. The present study was aimed to further characterize the role of FMRP in behavior and synaptic function by using fmr1 knockout zebrafish. In adult zebrafish, we found that fmr1 knockout produces the anxiolytic-like responses of increased exploratory behavior in light/dark and open-field tests and avoidance learning impairment. Furthermore, electrophysiological recordings from telencephalic slice preparations of knockout fish displayed markedly reduced long-term potentiation and enhanced long-term depression compared to wild-type fish; however, basal glutamatergic transmission and presynaptic function at the lateral (Dl) and medial (Dm) division of the dorsal telencephalon synapse remained normal. Taken together, our study not only evaluates the mechanism of FRMP but also suggests that zebrafish have valuable potential as a complementary vertebrate model in studying the molecular pathogenesis of human fragile X syndrome.

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

    PubMed

    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.

  1. Macrophage-pathogen interactions in infectious diseases: new therapeutic insights from the zebrafish host model.

    PubMed

    Torraca, Vincenzo; Masud, Samrah; Spaink, Herman P; Meijer, Annemarie H

    2014-07-01

    Studying macrophage biology in the context of a whole living organism provides unique possibilities to understand the contribution of this extremely dynamic cell subset in the reaction to infections, and has revealed the relevance of cellular and molecular processes that are fundamental to the cell-mediated innate immune response. In particular, various recently established zebrafish infectious disease models are contributing substantially to our understanding of the mechanisms by which different pathogens interact with macrophages and evade host innate immunity. Transgenic zebrafish lines with fluorescently labeled macrophages and other leukocyte populations enable non-invasive imaging at the optically transparent early life stages. Furthermore, there is a continuously expanding availability of vital reporters for subcellular compartments and for probing activation of immune defense mechanisms. These are powerful tools to visualize the activity of phagocytic cells in real time and shed light on the intriguing paradoxical roles of these cells in both limiting infection and supporting the dissemination of intracellular pathogens. This Review will discuss how several bacterial and fungal infection models in zebrafish embryos have led to new insights into the dynamic molecular and cellular mechanisms at play when pathogens encounter host macrophages. We also describe how these insights are inspiring novel therapeutic strategies for infectious disease treatment.

  2. The common neural parasite Pseudoloma neurophilia is associated with altered startle response habituation in adult zebrafish (Danio rerio): Implications for the zebrafish as a model organism

    PubMed Central

    Spagnoli, Sean; Xue, Lan; Kent, Michael L.

    2015-01-01

    The zebrafish’s potential as a model for human neurobehavioral research appears nearly limitless despite its relatively recent emergence as an experimental organism. Since the zebrafish has only been part of the research community for a handful of decades, pathogens from its commercial origins continue to plague laboratory stocks. One such pathogen is Pseudoloma neurophilia, a common microparasite in zebrafish laboratories world-wide that generally produces subclinical infections. Given its high prevalence, its predilection for the host’s brain and spinal cord, and the delicate nature of neurobehavioral research, the behavioral consequences of subclinical P. neurophilia infection must be explored. Fish infected via cohabitation were tested for startle response habituation in parallel with controls in a device that administered ten taps over ten minutes along with taps at 18 and 60 minutes to evaluate habituation extinction. After testing, fish were euthanized and evaluated for infection via histopathology. Infected fish had a significantly smaller reduction in startle velocity during habituation compared to uninfected tankmates and controls. Habituation was eliminated in infected and control fish at 18 minutes, whereas exposed negative fish retained partial habituation at 18 minutes. Infection was also associated with enhanced capture evasion: Despite the absence of external symptoms, infected fish tended to be caught later than uninfected fish netted from the same tank. The combination of decreased overall habituation, early extinction of habituation compared to uninfected cohorts, and enhanced netting evasion indicates that P. neurophilia infection is associated with a behavioral phenotype distinct from that of controls and uninfected cohorts. Because of its prevalence in zebrafish facilities, P. neurophilia has the potential to insidiously influence a wide range of neurobehavioral studies if these associations are causative. Rigorous health screening is

  3. Simplex PCR assay for positive identification of genetic sex in the Japanese medaka, Oryzias latipes.

    PubMed

    Patil, Jawahar G; Hinze, Susan J

    2008-01-01

    The medaka, Oryzias latipes, is a very popular model in biomedical research, particularly for elucidating sex differentiation and determination mechanisms and effects of endocrine disruptors among others. These studies require a sensitive, accurate, rapid, and reliable technique for genetic sexing of eggs, larvae, and adults. In this study, we report a simplex polymerase chain reaction approach that uses a single pair of primers for simultaneous amplification of sex-specific amplicons. Males and females yield a single diagnostic band of 933 and 1,906 bp, respectively, in three different strains of medaka tested, permitting gender identification accurately of both immature and adult fish. This technique will be useful in both ecological and biomedical researches that employ medaka and rely on genetic sexing.

  4. Biochemical characterization of the medaka (Oryzias latipes) orthologue for mammalian tissue-type transglutaminase (TG2).

    PubMed

    Takada, Yuki; Watanabe, Yuko; Okuya, Kazuho; Tatsukawa, Hideki; Hashimoto, Hisashi; Hitomi, Kiyotaka

    2017-03-01

    Transglutaminase is an enzyme family responsible for post-translational modification such as protein cross-linking and the attachment of primary amine and/or deamidation of glutamine-residue in proteins. Medaka (Oryzias latipes), a recently established model fish, has similar functional proteins to those characterized in mammals. Previously, we found the apparent orthologues that correspond to human transglutaminases in medaka. In this study, regarding the medaka orthologue of human tissue-type transglutaminase (OlTGT), recombinant protein was expressed in an active form in bacteria cultured at low temperature. Using the recombinant protein, we biochemically characterized the enzymatic activity and also obtained a monoclonal antibody that specifically recognized OlTGT. Immunochemical analysis revealed that OlTGT was not expressed ubiquitously, unlike its mammalian orthologue, but in primarily limited tissues such as the eye, brain, spinal cord, and gas gland.

  5. Using Zebrafish Models of Human Influenza A Virus Infections to Screen Antiviral Drugs and Characterize Host Immune Cell Responses.

    PubMed

    Sullivan, Con; Jurcyzszak, Denise; Goody, Michelle F; Gabor, Kristin A; Longfellow, Jacob R; Millard, Paul J; Kim, Carol H

    2017-01-20

    Each year, seasonal influenza outbreaks profoundly affect societies worldwide. In spite of global efforts, influenza remains an intractable healthcare burden. The principle strategy to curtail infections is yearly vaccination. In individuals who have contracted influenza, antiviral drugs can mitigate symptoms. There is a clear and unmet need to develop alternative strategies to combat influenza. Several animal models have been created to model host-influenza interactions. Here, protocols for generating zebrafish models for systemic and localized human influenza A virus (IAV) infection are described. Using a systemic IAV infection model, small molecules with potential antiviral activity can be screened. As a proof-of-principle, a protocol that demonstrates the efficacy of the antiviral drug Zanamivir in IAV-infected zebrafish is described. It shows how disease phenotypes can be quantified to score the relative efficacy of potential antivirals in IAV-infected zebrafish. In recent years, there has been increased appreciation for the critical role neutrophils play in the human host response to influenza infection. The zebrafish has proven to be an indispensable model for the study of neutrophil biology, with direct impacts on human medicine. A protocol to generate a localized IAV infection in the Tg(mpx:mCherry) zebrafish line to study neutrophil biology in the context of a localized viral infection is described. Neutrophil recruitment to localized infection sites provides an additional quantifiable phenotype for assessing experimental manipulations that may have therapeutic applications. Both zebrafish protocols described faithfully recapitulate aspects of human IAV infection. The zebrafish model possesses numerous inherent advantages, including high fecundity, optical clarity, amenability to drug screening, and availability of transgenic lines, including those in which immune cells such as neutrophils are labeled with fluorescent proteins. The protocols detailed here

  6. A TALEN-Exon Skipping Design for a Bethlem Myopathy Model in Zebrafish

    PubMed Central

    Elipot, Yannick; Bretaud, Sandrine; Arnould, Sylvain; Duchateau, Philippe; Ruggiero, Florence; Joly, Jean-Stéphane; Sohm, Frédéric

    2015-01-01

    Presently, human collagen VI-related diseases such as Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM) remain incurable, emphasizing the need to unravel their etiology and improve their treatments. In UCMD, symptom onset occurs early, and both diseases aggravate with ageing. In zebrafish fry, morpholinos reproduced early UCMD and BM symptoms but did not allow to study the late phenotype. Here, we produced the first zebrafish line with the human mutation frequently found in collagen VI-related disorders such as UCMD and BM. We used a transcription activator-like effector nuclease (TALEN) to design the col6a1ama605003-line with a mutation within an essential splice donor site, in intron 14 of the col6a1 gene, which provoke an in-frame skipping of exon 14 in the processed mRNA. This mutation at a splice donor site is the first example of a template-independent modification of splicing induced in zebrafish using a targetable nuclease. This technique is readily expandable to other organisms and can be instrumental in other disease studies. Histological and ultrastructural analyzes of homozygous and heterozygous mutant fry and 3 months post-fertilization (mpf) fish revealed co-dominantly inherited abnormal myofibers with disorganized myofibrils, enlarged sarcoplasmic reticulum, altered mitochondria and misaligned sarcomeres. Locomotion analyzes showed hypoxia-response behavior in 9 mpf col6a1 mutant unseen in 3 mpf fish. These symptoms worsened with ageing as described in patients with collagen VI deficiency. Thus, the col6a1ama605003-line is the first adult zebrafish model of collagen VI-related diseases; it will be instrumental both for basic research and drug discovery assays focusing on this type of disorders. PMID:26221953

  7. Embryonic Zebrafish Model - A Well-Established Method for Rapidly Assessing the Toxicity of Homeopathic Drugs

    PubMed Central

    Gupta, Himanshu R; Patil, Yogesh; Singh, Dipty

    2016-01-01

    in this study. The embryonic zebrafish model is recommended as a well-established method for rapidly assessing the toxicity of homeopathic drugs. PMID:28127503

  8. Tanshinone IIA Exhibits Anticonvulsant Activity in Zebrafish and Mouse Seizure Models

    PubMed Central

    2013-01-01

    Danshen or Chinese red sage (Salvia miltiorrhiza, Bunge) is used by traditional Chinese medicine (TCM) practitioners to treat neurological, cardiovascular, and cerebrovascular disorders and is included in some TCM formulations to control epileptic seizures. In this study, acetonic crude extracts of danshen inhibited pentylenetetrazol (PTZ)-induced seizure activity in zebrafish larvae. Subsequent zebrafish bioassay-guided fractionation of the extract resulted in the isolation of four major tanshinones, which suppressed PTZ-induced activity to varying degrees. One of the active tanshinones, tanshinone IIA, also reduced c-fos expression in the brains of PTZ-exposed zebrafish larvae. In rodent seizure models, tanshinone IIA showed anticonvulsive activity in the mouse 6-Hz psychomotor seizure test in a biphasic manner and modified seizure thresholds in a complex manner for the mouse i.v. PTZ seizure assay. Interestingly, tanshinone IIA is used as a prescription drug in China to address cerebral ischemia in patients. Here, we provide the first in vivo evidence demonstrating that tanshinone IIA has anticonvulsant properties as well. PMID:23937066

  9. Mind the fish: zebrafish as a model in cognitive social neuroscience

    PubMed Central

    Oliveira, Rui F.

    2013-01-01

    Understanding how the brain implements social behavior on one hand, and how social processes feedback on the brain to promote fine-tuning of behavioral output according to changes in the social environment is a major challenge in contemporary neuroscience. A critical step to take this challenge successfully is finding the appropriate level of analysis when relating social to biological phenomena. Given the enormous complexity of both the neural networks of the brain and social systems, the use of a cognitive level of analysis (in an information processing perspective) is proposed here as an explanatory interface between brain and behavior. A conceptual framework for a cognitive approach to comparative social neuroscience is proposed, consisting of the following steps to be taken across different species with varying social systems: (1) identification of the functional building blocks of social skills; (2) identification of the cognitive mechanisms underlying the previously identified social skills; and (3) mapping these information processing mechanisms onto the brain. Teleost fish are presented here as a group of choice to develop this approach, given the diversity of social systems present in closely related species that allows for planned phylogenetic comparisons, and the availability of neurogenetic tools that allows the visualization and manipulation of selected neural circuits in model species such as the zebrafish. Finally, the state-of-the art of zebrafish social cognition and of the tools available to map social cognitive abilities to neural circuits in zebrafish are reviewed. PMID:23964204

  10. Mind the fish: zebrafish as a model in cognitive social neuroscience.

    PubMed

    Oliveira, Rui F

    2013-01-01

    Understanding how the brain implements social behavior on one hand, and how social processes feedback on the brain to promote fine-tuning of behavioral output according to changes in the social environment is a major challenge in contemporary neuroscience. A critical step to take this challenge successfully is finding the appropriate level of analysis when relating social to biological phenomena. Given the enormous complexity of both the neural networks of the brain and social systems, the use of a cognitive level of analysis (in an information processing perspective) is proposed here as an explanatory interface between brain and behavior. A conceptual framework for a cognitive approach to comparative social neuroscience is proposed, consisting of the following steps to be taken across different species with varying social systems: (1) identification of the functional building blocks of social skills; (2) identification of the cognitive mechanisms underlying the previously identified social skills; and (3) mapping these information processing mechanisms onto the brain. Teleost fish are presented here as a group of choice to develop this approach, given the diversity of social systems present in closely related species that allows for planned phylogenetic comparisons, and the availability of neurogenetic tools that allows the visualization and manipulation of selected neural circuits in model species such as the zebrafish. Finally, the state-of-the art of zebrafish social cognition and of the tools available to map social cognitive abilities to neural circuits in zebrafish are reviewed.

  11. Zebrafish as a model organism to study host-pathogen interactions.

    PubMed

    Medina, Carlos; Royo, Jose Luis

    2013-08-15

    Zebrafish have been extensively used in biomedical research as a model to study vertebrate development but it is only recently that it has also been adopted into varied fields such as immunology and host-pathogen interactions. Zebrafish have a rapid life cycle, small size and the adults exhibit no territorial behavior in relatively dense cages. Under standard conditions each female lays an average of a hundred eggs per clutch, providing a large number of larvae per week. Their transparency during early life stages allows real time visualization of the different organs, which makes them especially suitable for the study of bacterial host-pathogen interactions. Traditionally, these studies have been technically challenging in higher organisms, given the loss of control over the bacteria once the pathogen infects its host. Here we describe an emerging approach to monitor Salmonella typhimurium infection progression using in vivo fluorescence upon parenteral infection. We have engineered Salmonella with the Cascade expression system; an efficient method to voluntarily activate bacterial heterologous gene expression at any point during infection once inside the Zebrafish macrophages, using a non-toxic inducer. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Susceptibility of zebrafish (Danio rerio) to a model pathogen, spring viremia of carp virus

    USGS Publications Warehouse

    Sanders, George E.; Batts, William N.; Winton, James R.

    2003-01-01

    To improve our understanding of the genetic basis of fish disease, we developed a pathogen model, using zebrafish (Danio rerio) and spring virema of carp virus (SVCV). Replicate groups of 10 fish were acclimated to 20 or 24°C, then were exposed to SVCV concentrations of 103 to 105 plaque-forming units per milliliter (PFU/ml) of water and observed daily. In a second trial, fish were acclimated to 15°C, and replicate groups of 10 fish were exposed to SVCV at a concentration of 105 PFU/ml; however, the temperature was raised 1°C/wk. Moribund fish were collected for histologic examination, and dead fish were assayed for virus by use of cell culture and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Mortality exceeded 50% in fish exposed to 105 PFU of SVCV/ml at the lower temperatures. Clinical signs of disease became evident seven days after viral exposure and were observed most consistently in fish of the 105 PFU/ml groups. Affected zebrafish were anorectic and listless, with epidermal petechial hemorrhages followed by death. Use of plaque assays and RT-PCR analysis confirmed presence of SVCV at titers ≥ 104 PFU/g of tissue. Histologic lesions included multifocal brachial necrosis and melanomacrophage proliferation in gills, liver, and kidneys. These results indicate that zebrafish are susceptible to infection by SVCV under conditions that mimic a natural route of exposure.

  13. Identification of compounds with anti-convulsant properties in a zebrafish model of epileptic seizures

    PubMed Central

    Baxendale, Sarah; Holdsworth, Celia J.; Meza Santoscoy, Paola L.; Harrison, Michael R. M.; Fox, James; Parkin, Caroline A.; Ingham, Philip W.; Cunliffe, Vincent T.

    2012-01-01

    SUMMARY The availability of animal models of epileptic seizures provides opportunities to identify novel anticonvulsants for the treatment of people with epilepsy. We found that exposure of 2-day-old zebrafish embryos to the convulsant agent pentylenetetrazole (PTZ) rapidly induces the expression of synaptic-activity-regulated genes in the CNS, and elicited vigorous episodes of calcium (Ca2+) flux in muscle cells as well as intense locomotor activity. We then screened a library of ∼2000 known bioactive small molecules and identified 46 compounds that suppressed PTZ-inducedtranscription of the synaptic-activity-regulated gene fos in 2-day-old (2 dpf) zebrafish embryos. Further analysis of a subset of these compounds, which included compounds with known and newly identified anticonvulsant properties, revealed that they exhibited concentration-dependent inhibition of both locomotor activity and PTZ-induced fos transcription, confirming their anticonvulsant characteristics. We conclude that this in situ hybridisation assay for fos transcription in the zebrafish embryonic CNS is a robust, high-throughput in vivo indicator of the neural response to convulsant treatment and lends itself well to chemical screening applications. Moreover, our results demonstrate that suppression of PTZ-induced fos expression provides a sensitive means of identifying compounds with anticonvulsant activities. PMID:22730455

  14. Vaccination with outer membrane vesicles from Francisella noatunensis reduces development of francisellosis in a zebrafish model.

    PubMed

    Brudal, Espen; Lampe, Elisabeth O; Reubsaet, Léon; Roos, Norbert; Hegna, Ida K; Thrane, Ida Marie; Koppang, Erling O; Winther-Larsen, Hanne C

    2015-01-01

    Infection of fish with the facultative intracellular bacterium Francisella noatunensis remains an unresolved problem for aquaculture industry worldwide as it is difficult to vaccinate against without using live attenuated vaccines. Outer membrane vesicles (OMVs) are biological structures shed by Gram-negative bacteria in response to various environmental stimuli. OMVs have successfully been used to vaccinate against both intracellular and extracellular pathogens, due to an ability to stimulate innate, cell-mediated and humoral immune responses. We show by using atomic force and electron microscopy that the fish pathogenic bacterium F. noatunensis subspecies noatunensis (F.n.n.) shed OMVs both in vitro into culture medium and in vivo in a zebrafish infection model. The main protein constituents of the OMV are IglC, PdpD and PdpA, all known Francisella virulence factors, in addition to the outer membrane protein FopA and the chaperonin GroEL, as analyzed by mass spectrometry. The vesicles, when used as a vaccine, reduced proliferation of the bacterium and protected zebrafish when subsequently challenged with a high dose of F.n.n. without causing adverse effects for the host. Also granulomatous responses were reduced in F.n.n.-challenged zebrafish after OMV vaccination. Taken together, the data support the possible use of OMVs as vaccines against francisellosis in fish. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Zebrafish fetal alcohol syndrome model: effects of ethanol are rescued by retinoic acid supplement.

    PubMed

    Marrs, James A; Clendenon, Sherry G; Ratcliffe, Don R; Fielding, Stephen M; Liu, Qin; Bosron, William F

    2010-01-01

    This study was designed to develop a zebrafish experimental model to examine defects in retinoic acid (RA) signaling caused by embryonic ethanol exposure. RA deficiency may be a causative factor leading to a spectrum of birth defects classified as fetal alcohol spectrum disorder (FASD). Experimental support for this hypothesis using Xenopus showed that effects of treatment with ethanol could be partially rescued by adding retinoids during ethanol treatment. Previous studies show that treating zebrafish embryos during gastrulation and somitogenesis stages with a pathophysiological concentration of ethanol (100mM) produces effects that are characteristic features of FASD. We found that treating zebrafish embryos with RA at a low concentration (10(-9)M) and 100mM ethanol during gastrulation and somitogenesis stages significantly rescued a spectrum of defects produced by treating embryos with 100mM ethanol alone. The rescued phenotype that we observed was quantitatively more similar to embryos treated with 10(-9)M RA alone (RA toxicity) than to untreated or 100mM ethanol-treated embryos. RA rescued defects caused by 100mM ethanol treatment during gastrulation and somitogenesis stages that include early gastrulation cell movements (anterior-posterior axis), craniofacial cartilage formation, and ear development. Morphological evidence also suggests that other characteristic features of FASD (e.g., neural axis patterning) are rescued by RA supplement.

  16. Assessment of Toxicological Perturbations and Variants of Pancreatic Islet Development in the Zebrafish Model.

    PubMed

    Sant, Karilyn E; Jacobs, Haydee M; Xu, Jiali; Borofski, Katrina A; Moss, Larry G; Moss, Jennifer B; Timme-Laragy, Alicia R

    2016-09-01

    The pancreatic islets, largely comprised of insulin-producing beta cells, play a critical role in endocrine signaling and glucose homeostasis. Because they have low levels of antioxidant defenses and a high perfusion rate, the endocrine islets may be a highly susceptible target tissue of chemical exposures. However, this endpoint, as well as the integrity of the surrounding exocrine pancreas, is often overlooked in studies of developmental toxicology. Disruption of development by toxicants can alter cell fate and migration, resulting in structural alterations that are difficult to detect in mammalian embryo systems, but that are easily observed in the zebrafish embryo model (Danio rerio). Using endogenously expressed fluorescent protein markers for developing zebrafish beta cells and exocrine pancreas tissue, we documented differences in islet area and incidence rates of islet morphological variants in zebrafish embryos between 48 and 96 h post fertilization (hpf), raised under control conditions commonly used in embryotoxicity assays. We identified critical windows for chemical exposures during which increased incidences of endocrine pancreas abnormalities were observed following exposure to cyclopamine (2-12 hpf), Mono-2-ethylhexyl phthalate (MEHP) (3-48 hpf), and Perfluorooctanesulfonic acid (PFOS) (3-48 hpf). Both islet area and length of the exocrine pancreas were sensitive to oxidative stress from exposure to the oxidant tert-butyl hydroperoxide during a highly proliferative critical window (72 hpf). Finally, pancreatic dysmorphogenesis following developmental exposures is discussed with respect to human disease.

  17. LARGE SCALE CARCINOGEN DOSE RESPONSE STUDIES WITH JAPANESE MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    To investigate the responses to low carcinogen doses in animal models, large sample sizes are needed and it is an advantage if the model has a low spontaneous tumor rate. Three large scale dose response studies were conducted using Japanese medaka and the carcinogen diethylnitros...

  18. LARGE SCALE CARCINOGEN DOSE RESPONSE STUDIES WITH JAPANESE MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    To investigate the responses to low carcinogen doses in animal models, large sample sizes are needed and it is an advantage if the model has a low spontaneous tumor rate. Three large scale dose response studies were conducted using Japanese medaka and the carcinogen diethylnitros...

  19. Development of a Novel and Robust Pharmacological Model of Okadaic Acid-induced Alzheimer's Disease in Zebrafish.

    PubMed

    Nada, Shadia E; Williams, Frederick E; Shah, Zahoor A

    2016-01-01

    Alzheimer's disease (AD) is the leading neurodegenerative disorder affecting the world's elderly population. Most experimental models of AD are transgenic or pharmacological in nature, and do not simulate the entire pathophysiology. In the present study, we developed a pharmacologically induced AD using the zebrafish, a species that can recapitulate most of the phenotypes of the disease. The pharmacological agent being used, okadaic acid (OKA) has also been utilized to study AD in other species. In this model, the immunohistochemistry of phosphorylated glycogen synthase-3α/β, Aβ, p-tau, tau protein, and senile plaque formation in zebrafish brain were all significantly increased with increasing exposure to OKA. These represent the majority of the histological hallmarks of AD pathophysiology. The observed changes were also accompanied by learning and memory deficits which are also important components in AD pathophysiology. Zebrafish disease models are gaining popularity mostly due to their economic cost and relevance to human disease pathophysiology. Current pharmacological methods of inducing AD in zebrafish are not adequately developed and do not represent all the features of the disease. OKA-induced AD in zebrafish can become a cost efficient model to study drug discovery for AD. It may also be used to unravel the molecular mechanisms underlying the complex pathophysiology that leads to AD using relatively economical species.

  20. Cross-species pharmacological characterization of the allylglycine seizure model in mice and larval zebrafish.

    PubMed

    Leclercq, Karine; Afrikanova, Tatiana; Langlois, Melanie; De Prins, An; Buenafe, Olivia E; Rospo, Chiara C; Van Eeckhaut, Ann; de Witte, Peter A M; Crawford, Alexander D; Smolders, Ilse; Esguerra, Camila V; Kaminski, Rafal M

    2015-04-01

    Treatment-resistant seizures affect about a third of patients suffering from epilepsy. To fulfill the need for new medications targeting treatment-resistant seizures, a number of rodent models offer the opportunity to assess a variety of potential treatment approaches. The use of such models, however, has proven to be time-consuming and labor-intensive. In this study, we performed pharmacological characterization of the allylglycine (AG) seizure model, a simple in vivo model for which we demonstrated a high level of treatment resistance. (d,l)-Allylglycine inhibits glutamic acid decarboxylase (GAD) - the key enzyme in γ-aminobutyric acid (GABA) biosynthesis - leading to GABA depletion, seizures, and neuronal damage. We performed a side-by-side comparison of mouse and zebrafish acute AG treatments including biochemical, electrographic, and behavioral assessments. Interestingly, seizure progression rate and GABA depletion kinetics were comparable in both species. Five mechanistically diverse antiepileptic drugs (AEDs) were used. Three out of the five AEDs (levetiracetam, phenytoin, and topiramate) showed only a limited protective effect (mainly mortality delay) at doses close to the TD50 (dose inducing motor impairment in 50% of animals) in mice. The two remaining AEDs (diazepam and sodium valproate) displayed protective activity against AG-induced seizures. Experiments performed in zebrafish larvae revealed behavioral AED activity profiles highly analogous to those obtained in mice. Having demonstrated cross-species similarities and limited efficacy of tested AEDs, we propose the use of AG in zebrafish as a convenient and high-throughput model of treatment-resistant seizures. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Switching to zebrafish neurobehavioral models: The obsessive-compulsive disorder paradigm.

    PubMed

    D'Amico, Davide; Estivill, Xavier; Terriente, Javier

    2015-07-15

    Obsessive-compulsive disorder (OCD) is the tenth most disabling illness of any kind. OCD stands as a paradigm for complex neurobehavioral disorders due to its polygenic origin. It presents heterogenic clinical presentation, variable disease onset, progression and treatment responses, what makes its understanding a major neuropsychiatric challenge. Like with other neurobehavioral disorders, animal models are essential tools for decoding OCD genetic complexity, understanding its biological base and discovering novel treatments and diagnostic methods. 20 years of rodent OCD modeling have helped to understand the disease better, but multiple questions remain regarding OCD. Innovative whole genome sequencing (WGS) approaches might provide important answers on OCD risk associated genes. However, exploiting those large data sets through the use of traditional animal models is costly and time consuming. Zebrafish might be an appropriate animal model to streamline the pipeline of gene functional validation. This animal model shows several advantages versus rodent models, such as faster and cheaper genetic manipulation, strong impact on the 3Rs implementation, behavioral phenotypic reproducibility of OCD-like behaviors (obsessions and compulsions) and feasibility to develop high-throughput assays for novel OCD drug therapies discovery. In conclusion, zebrafish could be an innovative and relevant model for understanding OCD.

  2. A GCSFR/CSF3R zebrafish mutant models the persistent basal neutrophil deficiency of severe congenital neutropenia

    PubMed Central

    Pazhakh, Vahid; Clark, Sharon; Keightley, M. Cristina; Lieschke, Graham J.

    2017-01-01

    Granulocyte colony-stimulating factor (GCSF) and its receptor (GCSFR), also known as CSF3 and CSF3R, are required to maintain normal neutrophil numbers during basal and emergency granulopoiesis in humans, mice and zebrafish. Previous studies identified two zebrafish CSF3 ligands and a single CSF3 receptor. Transient antisense morpholino oligonucleotide knockdown of both these ligands and receptor reduces neutrophil numbers in zebrafish embryos, a technique widely used to evaluate neutrophil contributions to models of infection, inflammation and regeneration. We created an allelic series of zebrafish csf3r mutants by CRISPR/Cas9 mutagenesis targeting csf3r exon 2. Biallelic csf3r mutant embryos are viable and have normal early survival, despite a substantial reduction of their neutrophil population size, and normal macrophage abundance. Heterozygotes have a haploinsufficiency phenotype with an intermediate reduction in neutrophil numbers. csf3r mutants are viable as adults, with a 50% reduction in tissue neutrophil density and a substantial reduction in the number of myeloid cells in the kidney marrow. These csf3r mutants are a new animal model of human CSF3R-dependent congenital neutropenia. Furthermore, they will be valuable for studying the impact of neutrophil loss in the context of other zebrafish disease models by providing a genetically stable, persistent, reproducible neutrophil deficiency state throughout life. PMID:28281657

  3. A privileged intraphagocyte niche is responsible for disseminated infection of Staphylococcus aureus in a zebrafish model

    PubMed Central

    Prajsnar, Tomasz K; Hamilton, Ruth; Garcia-Lara, Jorge; McVicker, Gareth; Williams, Alexander; Boots, Michael; Foster, Simon J; Renshaw, Stephen A

    2012-01-01

    The innate immune system is the primary defence against the versatile pathogen, Staphylococcus aureus. How this organism is able to avoid immune killing and cause infections is poorly understood. Using an established larval zebrafish infection model, we have shown that overwhelming infection is due to subversion of phagocytes by staphylococci, allowing bacteria to evade killing and found foci of disease. Larval zebrafish coinfected with two S. aureus strains carrying different fluorescent reporter gene fusions (but otherwise isogenic) had bacterial lesions, at the time of host death, containing predominantly one strain. Quantitative data using two marked strains revealed that the strain ratios, during overwhelming infection, were often skewed towards the extremes, with one strain predominating. Infection with passaged bacterial clones revealed the phenomenon not to bedue to adventitious mutations acquired by the pathogen. After infection of the host, all bacteria are internalized by phagocytes and the skewing of population ratios is absolutely dependent on the presence of phagocytes. Mathematical modelling of pathogen population dynamics revealed the data patterns are consistent with the hypothesis that a small number of infected phagocytes serve as an intracellular reservoir for S. aureus, which upon release leads to disseminated infection. Strategies to specifically alter neutrophil/macrophage numbers were used to map the potential subpopulation of phagocytes acting as a pathogen reservoir, revealing neutrophils as the likely ‘niche’. Subsequently in a murine sepsis model, S. aureus abscesses in kidneys were also found to be predominantly clonal, therefore likely founded by an individual cell, suggesting a potential mechanism analogous to the zebrafish model with few protected niches. These findings add credence to the argument that S. aureus control regimes should recognize both the intracellular as well as extracellular facets of the S. aureus life cycle

  4. A privileged intraphagocyte niche is responsible for disseminated infection of Staphylococcus aureus in a zebrafish model.

    PubMed

    Prajsnar, Tomasz K; Hamilton, Ruth; Garcia-Lara, Jorge; McVicker, Gareth; Williams, Alexander; Boots, Michael; Foster, Simon J; Renshaw, Stephen A

    2012-10-01

    The innate immune system is the primary defence against the versatile pathogen, Staphylococcus aureus. How this organism is able to avoid immune killing and cause infections is poorly understood. Using an established larval zebrafish infection model, we have shown that overwhelming infection is due to subversion of phagocytes by staphylococci, allowing bacteria to evade killing and found foci of disease. Larval zebrafish coinfected with two S. aureus strains carrying different fluorescent reporter gene fusions (but otherwise isogenic) had bacterial lesions, at the time of host death, containing predominantly one strain. Quantitative data using two marked strains revealed that the strain ratios, during overwhelming infection, were often skewed towards the extremes, with one strain predominating. Infection with passaged bacterial clones revealed the phenomenon not to bedue to adventitious mutations acquired by the pathogen. After infection of the host, all bacteria are internalized by phagocytes and the skewing of population ratios is absolutely dependent on the presence of phagocytes. Mathematical modelling of pathogen population dynamics revealed the data patterns are consistent with the hypothesis that a small number of infected phagocytes serve as an intracellular reservoir for S. aureus, which upon release leads to disseminated infection. Strategies to specifically alter neutrophil/macrophage numbers were used to map the potential subpopulation of phagocytes acting as a pathogen reservoir, revealing neutrophils as the likely 'niche'. Subsequently in a murine sepsis model, S. aureus abscesses in kidneys were also found to be predominantly clonal, therefore likely founded by an individual cell, suggesting a potential mechanism analogous to the zebrafish model with few protected niches. These findings add credence to the argument that S. aureus control regimes should recognize both the intracellular as well as extracellular facets of the S. aureus life

  5. 3640 unique EST clusters from the medaka testis and their potential use for identifying conserved testicular gene expression in fish and mammals.

    PubMed

    Lo, Lijan; Zhang, Zhenhai; Hong, Ni; Peng, Jinrong; Hong, Yunhan

    2008-01-01

    The fish medaka is the first vertebrate capable of full spermatogenesis in vitro from self-renewing spermatogonial stem cells to motile test-tube sperm. Precise staging and molecular dissection of this process has been hampered by the lack of suitable molecular markers. We have generated a normalized medaka testis cDNA library and obtained 7040 high quality sequences representing 3641 unique gene clusters. Among these, 1197 unique clusters are homologous to known genes, and 2444 appear to be novel genes. Ontology analysis shows that the 1197 gene products are implicated in diverse molecular and cellular processes. These genes include markers for all major types of testicular somatic and germ cells. Furthermore, markers were identified for major spermatogenic stages ranging from spermatogonial stem cell self-renewal to meiosis entry, progression and completion. Intriguingly, the medaka testis expresses at least 13 homologs of the 33 mouse X-chromosomal genes that are enriched in the testis. More importantly, we show that key components of several signaling pathways known to be important for testicular function in mammals are well represented in the medaka testicular EST collection. Medaka exhibits a considerable similarity in testicular gene expression to mammals. The medaka testicular EST collection we obtained has wide range coverage and will not only consolidate our knowledge on the comparative analysis of known genes' functions in the testis but also provide a rich resource to dissect molecular events and mechanism of spermatogenesis in vivo and in vitro in medaka as an excellent vertebrate model.

  6. Exposure to the synthetic FXR agonist GW4064 causes alterations in gene expression and sublethal hepatotoxicity in eleutheroembryo medaka (Oryzias latipes)

    SciTech Connect

    Howarth, Deanna L.; Law, Sheran H.W.; Law, J. McHugh; Mondon, J.A.; Kullman, Seth W.; Hinton, David E.

    2010-02-15

    The small freshwater teleost, medaka (Oryzias latipes), has a history of usage in studies of chronic toxicity of liver and biliary system. Recent progress with this model has focused on defining the medaka hepatobiliary system. Here we investigate critical liver function and toxicity by examining the in vivo role and function of the farnesoid X receptor alpha (FXRalpha, NR1H4), a member of the nuclear receptor superfamily that plays an essential role in the regulation of bile acid homeostasis. Quantitative mRNA analysis of medaka FXRalpha demonstrates differential expression of two FXRalpha isoforms designated Fxralpha1 and Fxralpha2, in both free swimming medaka embryos with remaining yolk (eleutheroembryos, EEs) and adults. Activation of medaka Fxralpha in vivo with GW4064 (a strong FXRalpha agonist) resulted in modification of gene expression for defined FXRalpha gene targets including the bile salt export protein, small heterodimer partner, and cytochrome P450 7A1. Histological examination of medaka liver subsequent to GW4064 exposure demonstrated significant lipid accumulation, cellular and organelle alterations in both hepatocytes and biliary epithelial cells of the liver. This report of hepatobiliary injury following GW4064 exposure extends previous investigations of the intrahepatic biliary system in medaka, reveals sensitivity to toxicant exposure, and illustrates the need for added resolution in detection and interpretation of toxic responses in this vertebrate.

  7. New insights into the pathogenesis of tuberculosis revealed by Mycobacterium marinum: the zebrafish model from the systems biology perspective.

    PubMed

    Deng, Wanyan; Tang, Xiemei; Hou, Manmei; Li, Chunmei; Xie, Jianping

    2011-01-01

    Tuberculosis remains a worldwide health concern, largely due to the emergence of multi-drug-resistant (MDR) and extensive-drug-resistant (XDR) Mycobacterium tuberculosis co-infection with HIV. The exact mechanism of Mycobacterium virulence, pathogenesis, and persistence is not fully understood. The hallmark of tuberculosis, granulomas are promoted by Mycobacterium virulence factors, and they have long been considered a structural advantage to the host. However, this traditional view has been challenged recently, largely due to the evidence originating from the M. marinum-zebrafish model. As a genetically tractable model, zebrafish provide unprecedented opportunities to address the pathogenesis of tuberculosis from a systems biology perspective. The latest data from this model are summarized in this review, special attention is given to the shared pathway and network between zebrafish and humans. This research serves to deepen our understanding of this complex process and to promote the discovery of better countermeasures against tuberculosis.

  8. A Zebrafish Model for Chlamydia Infection with the Obligate Intracellular Pathogen Waddlia chondrophila

    PubMed Central

    Fehr, Alexander G. J.; Ruetten, Maja; Seth-Smith, Helena M. B.; Nufer, Lisbeth; Voegtlin, Andrea; Lehner, Angelika; Greub, Gilbert; Crosier, Philip S.; Neuhauss, Stephan C. F.; Vaughan, Lloyd

    2016-01-01

    Obligate intracellular chlamydial bacteria of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) superphylum are important pathogens of terrestrial and marine vertebrates, yet many features of their pathogenesis and host specificity are still unknown. This is particularly true for families such as the Waddliacea which, in addition to epithelia, cellular targets for nearly all Chlamydia, can infect and replicate in macrophages, an important arm of the innate immune system or in their free-living amoebal counterparts. An ideal pathogen model system should include both host and pathogen, which led us to develop the first larval zebrafish model for chlamydial infections with Waddlia chondrophila. By varying the means and sites of application, epithelial cells of the swim bladder, endothelial cells of the vasculature and phagocytosing cells of the innate immune system became preferred targets for infection in zebrafish larvae. Through the use of transgenic zebrafish, we could observe recruitment of neutrophils to the infection site and demonstrate for the first time that W. chondrophila is taken up and replicates in these phagocytic cells and not only in macrophages. Furthermore, we present evidence that myeloid differentiation factor 88 (MyD88) mediated signaling plays a role in the innate immune reaction to W. chondrophila, eventually by Toll-like receptor (TLRs) recognition. Infected larvae with depleted levels of MyD88 showed a higher infection load and a lower survival rate compared to control fish. This work presents a new and potentially powerful non-mammalian experimental model to study the pathology of chlamydial virulence in vivo and opens up new possibilities for investigation of other members of the PVC superphylum. PMID:27917158

  9. Zebrafish as a Vertebrate Model System to Evaluate Effects of Environmental Toxicants on Cardiac Development and Function

    PubMed Central

    Sarmah, Swapnalee; Marrs, James A.

    2016-01-01

    Environmental pollution is a serious problem of the modern world that possesses a major threat to public health. Exposure to environmental pollutants during embryonic development is particularly risky. Although many pollutants have been verified as potential toxicants, there are new chemicals in the environment that need assessment. Heart development is an extremely sensitive process, which can be affected by environmentally toxic molecule exposure during embryonic development. Congenital heart defects are the most common life-threatening global health problems, and the etiology is mostly unknown. The zebrafish has emerged as an invaluable model to examine substance toxicity on vertebrate development, particularly on cardiac development. The zebrafish offers numerous advantages for toxicology research not found in other model systems. Many laboratories have used the zebrafish to study the effects of widespread chemicals in the environment on heart development, including pesticides, nanoparticles, and various organic pollutants. Here, we review the uses of the zebrafish in examining effects of exposure to external molecules during embryonic development in causing cardiac defects, including chemicals ubiquitous in the environment and illicit drugs. Known or potential mechanisms of toxicity and how zebrafish research can be used to provide mechanistic understanding of cardiac defects are discussed. PMID:27999267

  10. Zebrafish as a Vertebrate Model System to Evaluate Effects of Environmental Toxicants on Cardiac Development and Function.

    PubMed

    Sarmah, Swapnalee; Marrs, James A

    2016-12-16

    Environmental pollution is a serious problem of the modern world that possesses a major threat to public health. Exposure to environmental pollutants during embryonic development is particularly risky. Although many pollutants have been verified as potential toxicants, there are new chemicals in the environment that need assessment. Heart development is an extremely sensitive process, which can be affected by environmentally toxic molecule exposure during embryonic development. Congenital heart defects are the most common life-threatening global health problems, and the etiology is mostly unknown. The zebrafish has emerged as an invaluable model to examine substance toxicity on vertebrate development, particularly on cardiac development. The zebrafish offers numerous advantages for toxicology research not found in other model systems. Many laboratories have used the zebrafish to study the effects of widespread chemicals in the environment on heart development, including pesticides, nanoparticles, and various organic pollutants. Here, we review the uses of the zebrafish in examining effects of exposure to external molecules during embryonic development in causing cardiac defects, including chemicals ubiquitous in the environment and illicit drugs. Known or potential mechanisms of toxicity and how zebrafish research can be used to provide mechanistic understanding of cardiac defects are discussed.

  11. A first generation physical map of the medaka genome in BACs essential for positional cloning and clone-by-clone based genomic sequencing.

    PubMed

    Khorasani, Maryam Zadeh; Hennig, Steffen; Imre, Gabriele; Asakawa, Shuichi; Palczewski, Stefanie; Berger, Anja; Hori, Hiroshi; Naruse, Kiyoshi; Mitani, Hiroshi; Shima, Akihiro; Lehrach, Hans; Wittbrodt, Jochen; Kondoh, Hisato; Shimizu, Nobuyoshi; Himmelbauer, Heinz

    2004-07-01

    In order to realize the full potential of the medaka as a model system for developmental biology and genetics, characterized genomic resources need to be established, culminating in the sequence of the medaka genome. To facilitate the map-based cloning of genes underlying induced mutations and to provide templates for clone-based genomic sequencing, we have created a first-generation physical map of the medaka genome in bacterial artificial chromosome (BAC) clones. In particular, we exploited the synteny to the closely related genome of the pufferfish, Takifugu rubripes, by marker content mapping. As a first step, we clustered 103,144 public medaka EST sequences to obtain a set of 21,121 non-redundant sequence entities. Avoiding oversampling of gene-dense regions, 11,254 of EST clusters were successfully matched against the draft sequence of the fugu genome, and 2363 genes were selected for the BAC map project. We designed 35mer oligonucleotide probes from the selected genes and hybridized them against 64,500 BAC clones of strains Cab and Hd-rR, representing 14-fold coverage of the medaka genome. Our data set is further supplemented with 437 results generated from PCR-amplified inserts of medaka cDNA clones and BAC end-fragment markers. Our current, edited, first generation medaka BAC map consists of 902 map segments that cover about 74% of the medaka genome. The map contains 2721 markers. Of these, 2534 are from expressed sequences, equivalent to a non-redundant set of 2328 loci. The 934 markers (724 different) are anchored to the medaka genetic map. Thus, genetic map assignments provide immediate access to underlying clones and contigs, simplifying molecular access to candidate gene regions and their characterization.

  12. Gene knockdown by morpholino-modified oligonucleotides in the zebrafish (Danio rerio) model: applications for developmental toxicology.

    PubMed

    Timme-Laragy, Alicia R; Karchner, Sibel I; Hahn, Mark E

    2012-01-01

    The zebrafish (Danio rerio) has long been used as a model for developmental biology, making it an excellent model to use also in developmental toxicology. The many advantages of zebrafish include their small size, prolific spawning, rapid development, and transparent embryos. They can be easily manipulated genetically through the use of transgenic technology and gene knockdown via morpholino-modified antisense oligonucleotides (MOs). Knocking down specific genes to assess their role in the response to toxicant exposure provides a way to further our knowledge of how developmental toxicants work on a molecular and mechanistic level while establishing a relationship between these molecular events and morphological, behavioral, and/or physiological effects (i.e., phenotypic anchoring). In this chapter, we address important considerations for using MOs to study developmental toxicology in zebrafish embryos and provide a protocol for their use.

  13. Breaking symmetry: the zebrafish as a model for understanding left-right asymmetry in the developing brain.

    PubMed

    Roussigne, Myriam; Blader, Patrick; Wilson, Stephen W

    2012-03-01

    How does left-right asymmetry develop in the brain and how does the resultant asymmetric circuitry impact on brain function and lateralized behaviors? By enabling scientists to address these questions at the levels of genes, neurons, circuitry and behavior,the zebrafish model system provides a route to resolve the complexity of brain lateralization. In this review, we present the progress made towards characterizing the nature of the gene networks and the sequence of morphogenetic events involved in the asymmetric development of zebrafish epithalamus. In an attempt to integrate the recent extensive knowledge into a working model and to identify the future challenges,we discuss how insights gained at a cellular/developmental level can be linked to the data obtained at a molecular/genetic level. Finally, we present some evolutionary thoughts and discuss how significant discoveries made in zebrafish should provide entry points to better understand the evolutionary origins of brain lateralization.

  14. A zebrafish model of manganism reveals reversible and treatable symptoms that are independent of neurotoxicity

    PubMed Central

    Bakthavatsalam, Subha; Das Sharma, Shreya; Sonawane, Mahendra; Thirumalai, Vatsala; Datta, Ankona

    2014-01-01

    Manganese (manganese ion; referred to as Mn) is essential for neuronal function, yet it is toxic at high concentrations. Environmental and occupational exposure to high concentrations of Mn causes manganism, a well-defined movement disorder in humans, with symptoms resembling Parkinson’s disease (PD). However, manganism is distinct from PD and the neural basis of its pathology is poorly understood. To address this issue, we generated a zebrafish model of manganism by incubating larvae in rearing medium containing Mn. We find that Mn-treated zebrafish larvae exhibit specific postural and locomotor defects. Larvae begin to float on their sides, show a curved spine and swim in circles. We discovered that treatment with Mn causes postural defects by interfering with mechanotransduction at the neuromasts. Furthermore, we find that the circling locomotion could be caused by long-duration bursting in the motor neurons, which can lead to long-duration tail bends in the Mn-treated larvae. Mn-treated larvae also exhibited fewer startle movements. Additionally, we show that the intensity of tyrosine hydroxylase immunoreactivity is reversibly reduced after Mn-treatment. This led us to propose that reduced dopamine neuromodulation drives the changes in startle movements. To test this, when we supplied an external source of dopamine to Mn-treated larvae, the larvae exhibited a normal number of startle swims. Taken together, these results indicate that Mn interferes with neuronal function at the sensory, motor and modulatory levels, and open avenues for therapeutically targeted studies on the zebrafish model of manganism. PMID:25261567

  15. An inducible krasV12 transgenic zebrafish model for liver tumorigenesis and chemical drug screening

    PubMed Central

    Nguyen, Anh Tuan; Emelyanov, Alexander; Koh, Chor Hui Vivien; Spitsbergen, Jan M.; Parinov, Serguei; Gong, Zhiyuan

    2012-01-01

    SUMMARY Because Ras signaling is frequently activated by major hepatocellular carcinoma etiological factors, a transgenic zebrafish constitutively expressing the krasV12 oncogene in the liver was previously generated by our laboratory. Although this model depicted and uncovered the conservation between zebrafish and human liver tumorigenesis, the low tumor incidence and early mortality limit its use for further studies of tumor progression and inhibition. Here, we employed a mifepristone-inducible transgenic system to achieve inducible krasV12 expression in the liver. The system consisted of two transgenic lines: the liver-driver line had a liver-specific fabp10 promoter to produce the LexPR chimeric transactivator, and the Ras-effector line contained a LexA-binding site to control EGFP-krasV12 expression. In double-transgenic zebrafish (driver-effector) embryos and adults, we demonstrated mifepristone-inducible EGFP-krasV12 expression in the liver. Robust and homogeneous liver tumors developed in 100% of double-transgenic fish after 1 month of induction and the tumors progressed from hyperplasia by 1 week post-treatment (wpt) to carcinoma by 4 wpt. Strikingly, liver tumorigenesis was found to be ‘addicted’ to Ras signaling for tumor maintenance, because mifepristone withdrawal led to tumor regression via cell death in transgenic fish. We further demonstrated the potential use of the transparent EGFP-krasV12 larvae in inhibitor treatments to suppress Ras-driven liver tumorigenesis by targeting its downstream effectors, including the Raf-MEK-ERK and PI3K-AKT-mTOR pathways. Collectively, this mifepristone-inducible and reversible krasV12 transgenic system offers a novel model for understanding hepatocarcinogenesis and a high-throughput screening platform for anti-cancer drugs. PMID:21903676

  16. Ethanol teratogenesis in Japanese medaka: effects at the cellular level.

    PubMed

    Wu, Minghui; Chaudhary, Amit; Khan, Ikhlas A; Dasmahapatra, Asok K

    2008-01-01

    The adverse effects of alcohol on the developing humans represent a spectrum of structural and neurobehavioral abnormalities, most appropriately termed as fetal alcohol spectrum disorder (FASD). The mechanism by which ethanol induces FASD is unknown. Human studies of FASD are very limited due to ethical constraints; however, several animal models from nematodes to mammals are utilized to understand the molecular mechanism of this disorder. We have used Japanese medaka (Oryzias latipes) embryo-larval development as a unique non-mammalian model to study the molecular mechanism of FASD. Fertilized medaka eggs were exposed to ethanol (0-400 mM) for 48 h post fertilization (hpf) and then maintained in regular embryo rearing medium without ethanol. Viable embryos were harvested on 0, 2, 4 and 6 day post fertilization (dpf) and analyzed for DNA, RNA and protein contents of the embryos. By applying semi-quantitative RT-PCR (rRT-PCR) and quantitative real-time RT-PCR (qRT-PCR), RNA samples were further analyzed for seven transcription factors, emx2, en2, iro3, otx2, shh, wnt1 and zic5 which are expressed in the neural tube of medaka embryo during early phase of development. RNA and protein contents of the embryos were significantly reduced by ethanol at 400 mM dose on 4 and 6 dpf compared to the control (no ethanol), and 100 mM ethanol treated embryos. However, significant reduction of DNA was observed only in 4 dpf embryos. Total protein contents of yolk remained unaltered after ethanol treatment. Expression pattern of emx2, en2, iro3, otx2, shh, wnt1, and zic5 mRNAs were found to be developmentally regulated, however, remained unaltered after ethanol treatment. It is therefore concluded that alteration of nucleic acid and protein contents of medaka embryo by ethanol could be used as an indicator of embryonic growth retardation which might be the result of disruption of specific gene function during development.

  17. The Zebrafish Brain in Research and Teaching: A Simple in Vivo and in Vitro Model for the Study of Spontaneous Neural Activity

    ERIC Educational Resources Information Center

    Vargas, R.; Johannesdottir, I. P.; Sigurgeirsson, B.; Porsteinsson, H.; Karlsson, K. AE.

    2011-01-01

    Recently, the zebrafish ("Danio rerio") has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits.…

  18. The Zebrafish Brain in Research and Teaching: A Simple in Vivo and in Vitro Model for the Study of Spontaneous Neural Activity

    ERIC Educational Resources Information Center

    Vargas, R.; Johannesdottir, I. P.; Sigurgeirsson, B.; Porsteinsson, H.; Karlsson, K. AE.

    2011-01-01

    Recently, the zebrafish ("Danio rerio") has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits.…

  19. Zebrafish erythropoiesis and the utility of fish as models of anemia

    PubMed Central

    2012-01-01

    Erythrocytes contain oxygen-carrying hemoglobin to all body cells. Impairments in the generation of erythrocytes, a process known as erythropoiesis, or in hemoglobin synthesis alter cell function because of decreased oxygen supply and lead to anemic diseases. Thus, understanding how erythropoiesis is regulated during embryogenesis and adulthood is important to develop novel therapies for anemia. The zebrafish, Danio rerio, provides a powerful model for such study. Their small size and the ability to generate a large number of embryos enable large-scale analysis, and their transparency facilitates the visualization of erythroid cell migration. Importantly, the high conservation of hematopoietic genes among vertebrates and the ability to successfully transplant hematopoietic cells into fish have enabled the establishment of models of human anemic diseases in fish. In this review, we summarize the current progress in our understanding of erythropoiesis on the basis of zebrafish studies and highlight fish models of human anemias. These analyses could enable the discovery of novel drugs as future therapies. PMID:23257067

  20. Zebrafish erythropoiesis and the utility of fish as models of anemia.

    PubMed

    Kulkeaw, Kasem; Sugiyama, Daisuke

    2012-12-20

    Erythrocytes contain oxygen-carrying hemoglobin to all body cells. Impairments in the generation of erythrocytes, a process known as erythropoiesis, or in hemoglobin synthesis alter cell function because of decreased oxygen supply and lead to anemic diseases. Thus, understanding how erythropoiesis is regulated during embryogenesis and adulthood is important to develop novel therapies for anemia. The zebrafish, Danio rerio, provides a powerful model for such study. Their small size and the ability to generate a large number of embryos enable large-scale analysis, and their transparency facilitates the visualization of erythroid cell migration. Importantly, the high conservation of hematopoietic genes among vertebrates and the ability to successfully transplant hematopoietic cells into fish have enabled the establishment of models of human anemic diseases in fish. In this review, we summarize the current progress in our understanding of erythropoiesis on the basis of zebrafish studies and highlight fish models of human anemias. These analyses could enable the discovery of novel drugs as future therapies.

  1. Toxicogenomics to Evaluate Endocrine Disrupting Effects of Environmental Chemicals Using the Zebrafish Model

    PubMed Central

    Caballero-Gallardo, Karina; Olivero-Verbel, Jesus; Freeman, Jennifer L.

    2016-01-01

    The extent of our knowledge on the number of chemical compounds related to anthropogenic activities that can cause damage to the environment and to organisms is increasing. Endocrine disrupting chemicals (EDCs) are one group of potentially hazardous substances that include natural and synthetic chemicals and have the ability to mimic endogenous hormones, interfering with their biosynthesis, metabolism, and normal functions. Adverse effects associated with EDC exposure have been documented in aquatic biota and there is widespread interest in the characterization and understanding of their modes of action. Fish are considered one of the primary risk organisms for EDCs. Zebrafish (Danio rerio) are increasingly used as an animal model to study the effects of endocrine disruptors, due to their advantages compared to other model organisms. One approach to assess the toxicity of a compound is to identify those patterns of gene expression found in a tissue or organ exposed to particular classes of chemicals, through new technologies in genomics (toxicogenomics), such as microarrays or whole-genome sequencing. Application of these technologies permit the quantitative analysis of thousands of gene expression changes simultaneously in a single experiment and offer the opportunity to use transcript profiling as a tool to predict toxic outcomes of exposure to particular compounds. The application of toxicogenomic tools for identification of chemicals with endocrine disrupting capacity using the zebrafish model system is reviewed. PMID:28217008

  2. Use of the Zebrafish Larvae as a Model to Study Cigarette Smoke Condensate Toxicity

    PubMed Central

    Ellis, Lee D.; Soo, Evelyn C.; Achenbach, John C.; Morash, Michael G.; Soanes, Kelly H.

    2014-01-01

    The smoking of tobacco continues to be the leading cause of premature death worldwide and is linked to the development of a number of serious illnesses including heart disease, respiratory diseases, stroke and cancer. Currently, cell line based toxicity assays are typically used to gain information on the general toxicity of cigarettes and other tobacco products. However, they provide little information regarding the complex disease-related changes that have been linked to smoking. The ethical concerns and high cost associated with mammalian studies have limited their widespread use for in vivo toxicological studies of tobacco. The zebrafish has emerged as a low-cost, high-throughput, in vivo model in the study of toxicology. In this study, smoke condensates from 2 reference cigarettes and 6 Canadian brands of cigarettes with different design features were assessed for acute, developmental, cardiac, and behavioural toxicity (neurotoxicity) in zebrafish larvae. By making use of this multifaceted approach we have developed an in vivo model with which to compare the toxicity profiles of smoke condensates from cigarettes with different design features. This model system may provide insights into the development of smoking related disease and could provide a cost-effective, high-throughput platform for the future evaluation of tobacco products. PMID:25526262

  3. Toxicogenomics to Evaluate Endocrine Disrupting Effects of Environmental Chemicals Using the Zebrafish Model.

    PubMed

    Caballero-Gallardo, Karina; Olivero-Verbel, Jesus; Freeman, Jennifer L

    2016-12-01

    The extent of our knowledge on the number of chemical compounds related to anthropogenic activities that can cause damage to the environment and to organisms is increasing. Endocrine disrupting chemicals (EDCs) are one group of potentially hazardous substances that include natural and synthetic chemicals and have the ability to mimic endogenous hormones, interfering with their biosynthesis, metabolism, and normal functions. Adverse effects associated with EDC exposure have been documented in aquatic biota and there is widespread interest in the characterization and understanding of their modes of action. Fish are considered one of the primary risk organisms for EDCs. Zebrafish (Danio rerio) are increasingly used as an animal model to study the effects of endocrine disruptors, due to their advantages compared to other model organisms. One approach to assess the toxicity of a compound is to identify those patterns of gene expression found in a tissue or organ exposed to particular classes of chemicals, through new technologies in genomics (toxicogenomics), such as microarrays or whole-genome sequencing. Application of these technologies permit the quantitative analysis of thousands of gene expression changes simultaneously in a single experiment and offer the opportunity to use transcript profiling as a tool to predict toxic outcomes of exposure to particular compounds. The application of toxicogenomic tools for identification of chemicals with endocrine disrupting capacity using the zebrafish model system is reviewed.

  4. Hypoxia-Induced Retinal Neovascularization in Zebrafish Embryos: A Potential Model of Retinopathy of Prematurity

    PubMed Central

    Kao, Alex; Hsi, Brian; Lee, Shwu-Huey; Chen, Yau-Hung; Wang, I-Jong

    2015-01-01

    Retinopathy of prematurity, formerly known as a retrolental fibroplasia, is a leading cause of infantile blindness worldwide. Retinopathy of prematurity is caused by the failure of central retinal vessels to reach the retinal periphery, creating a nonperfused peripheral retina, resulting in retinal hypoxia, neovascularization, vitreous hemorrhage, vitreoretinal fibrosis, and loss of vision. We established a potential retinopathy of prematurity model by using a green fluorescent vascular endothelium zebrafish transgenic line treated with cobalt chloride (a hypoxia-inducing agent), followed by GS4012 (a vascular endothelial growth factor inducer) at 24 hours postfertilization, and observed that the number of vascular branches and sprouts significantly increased in the central retinal vascular trunks 2–4 days after treatment. We created an angiography method by using tetramethylrhodamine dextran, which exhibited severe vascular leakage through the vessel wall into the surrounding retinal tissues. The quantification of mRNA extracted from the heads of the larvae by using real-time quantitative polymerase chain reaction revealed a twofold increase in vegfaa and vegfr2 expression compared with the control group, indicating increased vascular endothelial growth factor signaling in the hypoxic condition. In addition, we demonstrated that the hypoxic insult could be effectively rescued by several antivascular endothelial growth factor agents such as SU5416, bevacizumab, and ranibizumab. In conclusion, we provide a simple, highly reproducible, and clinically relevant retinopathy of prematurity model based on zebrafish embryos; this model may serve as a useful platform for clarifying the mechanisms of human retinopathy of prematurity and its progression. PMID:25978439

  5. Neurodegeneration and Epilepsy in a Zebrafish Model of CLN3 Disease (Batten Disease)

    PubMed Central

    Fu, Sonia; Cooper, Jonathan D.; Harvey, Robert J.

    2016-01-01

    The neuronal ceroid lipofuscinoses are a group of lysosomal storage disorders that comprise the most common, genetically heterogeneous, fatal neurodegenerative disorders of children. They are characterised by childhood onset, visual failure, epileptic seizures, psychomotor retardation and dementia. CLN3 disease, also known as Batten disease, is caused by autosomal recessive mutations in the CLN3 gene, 80–85% of which are a ~1 kb deletion. Currently no treatments exist, and after much suffering, the disease inevitably results in premature death. The aim of this study was to generate a zebrafish model of CLN3 disease using antisense morpholino injection, and characterise the pathological and functional consequences of Cln3 deficiency, thereby providing a tool for future drug discovery. The model was shown to faithfully recapitulate the pathological signs of CLN3 disease, including reduced survival, neuronal loss, retinopathy, axonopathy, loss of motor function, lysosomal storage of subunit c of mitochondrial ATP synthase, and epileptic seizures, albeit with an earlier onset and faster progression than the human disease. Our study provides proof of principle that the advantages of the zebrafish over other model systems can be utilised to further our understanding of the pathogenesis of CLN3 disease and accelerate drug discovery. PMID:27327661

  6. Hypoxia-induced retinal neovascularization in zebrafish embryos: a potential model of retinopathy of prematurity.

    PubMed

    Wu, Yu-Ching; Chang, Chao-Yuan; Kao, Alex; Hsi, Brian; Lee, Shwu-Huey; Chen, Yau-Hung; Wang, I-Jong

    2015-01-01

    Retinopathy of prematurity, formerly known as a retrolental fibroplasia, is a leading cause of infantile blindness worldwide. Retinopathy of prematurity is caused by the failure of central retinal vessels to reach the retinal periphery, creating a nonperfused peripheral retina, resulting in retinal hypoxia, neovascularization, vitreous hemorrhage, vitreoretinal fibrosis, and loss of vision. We established a potential retinopathy of prematurity model by using a green fluorescent vascular endothelium zebrafish transgenic line treated with cobalt chloride (a hypoxia-inducing agent), followed by GS4012 (a vascular endothelial growth factor inducer) at 24 hours postfertilization, and observed that the number of vascular branches and sprouts significantly increased in the central retinal vascular trunks 2-4 days after treatment. We created an angiography method by using tetramethylrhodamine dextran, which exhibited severe vascular leakage through the vessel wall into the surrounding retinal tissues. The quantification of mRNA extracted from the heads of the larvae by using real-time quantitative polymerase chain reaction revealed a twofold increase in vegfaa and vegfr2 expression compared with the control group, indicating increased vascular endothelial growth factor signaling in the hypoxic condition. In addition, we demonstrated that the hypoxic insult could be effectively rescued by several antivascular endothelial growth factor agents such as SU5416, bevacizumab, and ranibizumab. In conclusion, we provide a simple, highly reproducible, and clinically relevant retinopathy of prematurity model based on zebrafish embryos; this model may serve as a useful platform for clarifying the mechanisms of human retinopathy of prematurity and its progression.

  7. Role of the endocannabinoid system in vertebrates: Emphasis on the zebrafish model.

    PubMed

    Oltrabella, Francesca; Melgoza, Adam; Nguyen, Brian; Guo, Su

    2017-05-01

    The endocannabinoid system (eCBs), named after the plant Cannabis sativa, comprises cannabinoid receptors, endogenous ligands known as "endocannabinoids", and enzymes involved in the biosynthesis and degradation of these ligands, as well as putative transporters for these ligands. ECBs proteins and small molecules have been detected in early embryonic stages of many vertebrate models. As a result, cannabinoid receptors and endogenous as well as exogenous cannabinoids influence development and behavior in many vertebrate species. Understanding the precise mechanisms of action for the eCBs will provide an invaluable guide towards elucidation of vertebrate development and will also help delineate how developmental exposure to marijuana might impact health and cognitive/executive functioning in adulthood. Here we review the developmental roles of the eCBs in vertebrates, focusing our attention on the zebrafish model. Since little is known regarding the eCBs in zebrafish, we provide new data on the expression profiles of eCBs genes during development and in adult tissue types of this model organism. We also highlight exciting areas for future investigations, including the synaptic regulation of eCBs, its role in reward and addiction, and in nervous system development and plasticity. © 2017 Japanese Society of Developmental Biologists.

  8. Fetal Origins of Life Stage Disease: A Zebrafish Model for the ...

    EPA Pesticide Factsheets

    In the U.S., childhood obesity has more than doubled in children and quadrupled in adolescents in the past 30 years, affects 35% of adults, and costs the U.S. healthcare industry >$200 billion annually. The chemical environment in the womb may cause susceptibility to different life-stage and life-long metabolic diseases including obesity. The challenge is to understand if exposures during developmentally sensitive windows impact life-stage disease, such as obesity, by increasing adipose tissue mass. In vitro models lack the integrated systems approach needed to assess adipose development, while mammalian models are impractical in a screen of thousands of chemicals. Therefore, an obesogen screening method was developed to interrogate bioactivity using a full systems approach, in a vertebrate zebrafish model with complete metabolic activity, at a time when the full signaling repertoire is expressed and active, to optimally examine how chemical dose and duration impact life-stage adipose mass. A time-line for adipose depot formation was mapped in zebrafish 6−14 days post fertilization (dpf) using the lipophilic dye, Nile Red, in combination with fluorescent microscopy. Those time points were then used to investigate the impact of embryonic tributyltin chloride (TBT, a known obesogen) exposure (10nM daily renewal, 0−5dpf) on adipose mass. Fluorescent microscopy revealed adipose depots that were larger and appeared 2 days earlier in TBT treated compared to contro

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

    PubMed

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

    2016-04-15

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

  10. A Zebrafish Model for Uremic Toxicity: Role of the Complement Pathway

    PubMed Central

    Thurman, Josh; Reinecke, James; Raff, Amanda C.; Melamed, Michal L.; Reinecke, James; Quan, Zhe; Evans, Todd; Meyer, Timothy W.; Hostetter, Thomas H

    2016-01-01

    Many organic solutes accumulate in ESRD and some are poorly removed removed with urea based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients pre-dialysis or from normal subjects. Zebrafish embryos 24 hours post fertilization were exposed to experimental media at a ratio of 3:1 water:human serum. Those exposed to serum from uremic subjects had significantly reduced survival at 8 hours (19% +/− 18% vs. 94% +/− 6%; p < 0.05, uremic serum vs control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50kD showed significantly greater toxicity with the larger molecular weight fraction (83% +/− 11% vs 7% +/−17% survival, p < 0.05, <50kD vs >50 kD, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96%+/− 5% vs 28%+/− 20% survival, p < 0.016, chelated vs non chelated serum respectively). Anti- factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98% +/− 6% vs. 3% +/− 9% survival, p < 0.016, anti- factor B treated vs non treated, respectively).Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and non-specific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. PMID:23689420

  11. A zebrafish model for uremic toxicity: role of the complement pathway.

    PubMed

    Berman, Nathaniel; Lectura, Melisa; Thurman, Joshua M; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

    2013-01-01

    Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p < 0.05, uremic serum vs. control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50 kDa showed significantly greater toxicity with the larger molecular weight fraction (83 ± 11 vs. 7 ± 17% survival, p < 0.05, <50 vs. >50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement.

  12. The genetic heterogeneity and mutational burden of engineered melanomas in zebrafish models

    PubMed Central

    2013-01-01

    Background Melanoma is the most deadly form of skin cancer. Expression of oncogenic BRAF or NRAS, which are frequently mutated in human melanomas, promote the formation of nevi but are not sufficient for tumorigenesis. Even with germline mutated p53, these engineered melanomas present with variable onset and pathology, implicating additional somatic mutations in a multi-hit tumorigenic process. Results To decipher the genetics of these melanomas, we sequence the protein coding exons of 53 primary melanomas generated from several BRAFV600E or NRASQ61K driven transgenic zebrafish lines. We find that engineered zebrafish melanomas show an overall low mutation burden, which has a strong, inverse association with the number of initiating germline drivers. Although tumors reveal distinct mutation spectrums, they show mostly C > T transitions without UV light exposure, and enrichment of mutations in melanogenesis, p53 and MAPK signaling. Importantly, a recurrent amplification occurring with pre-configured drivers BRAFV600E and p53-/- suggests a novel path of BRAF cooperativity through the protein kinase A pathway. Conclusion This is the first analysis of a melanoma mutational landscape in the absence of UV light, where tumors manifest with remarkably low mutation burden and high heterogeneity. Genotype specific amplification of protein kinase A in cooperation with BRAF and p53 mutation suggests the involvement of melanogenesis in these tumors. This work is important for defining the spectrum of events in BRAF or NRAS driven melanoma in the absence of UV light, and for informed exploitation of models such as transgenic zebrafish to better understand mechanisms leading to human melanoma formation. PMID:24148783

  13. Gucy2f zebrafish knockdown – a model for Gucy2d-related leber congenital amaurosis

    PubMed Central

    Stiebel-Kalish, Hadas; Reich, Ehud; Rainy, Nir; Vatine, Gad; Nisgav, Yael; Tovar, Anna; Gothilf, Yoav; Bach, Michael

    2012-01-01

    Mutations in retinal-specific guanylate cyclase (Gucy2d) are associated with Leber congenital amaurosis-1 (LCA1). Zebrafish offer unique advantages relative to rodents, including their excellent color vision, precocious retinal development, robust visual testing strategies, low cost, relatively easy transgenesis and shortened experimental times. In this study we will demonstrate the feasibility of using gene-targeting in the zebrafish as a model for the photoreceptor-specific GUCY2D-related LCA1, by reporting the visual phenotype and retinal histology resulting from Gucy2f knockdown. Gucy2f zebrafish LCA-orthologous cDNA was identified and isolated by PCR amplification. Its expression pattern was determined by whole-mount in-situ hybridization and its function was studied by gene knockdown using two different morpholino-modified oligos (MO), one that blocks translation of Gucy2f and one that blocks splicing of Gucy2f. Visual function was assessed with an optomotor assay on 6-days-post-fertilization larvae, and by analyzing changes in retinal histology. Gucy2f knockdown resulted in significantly lower vision as measured by the optomotor response compared with uninjected and control MO-injected zebrafish larvae. Histological changes in the Gucy2f-knockdown larvae included loss and shortening of cone and rod outer segments. A zebrafish model of Gucy2f-related LCA1 displays early visual dysfunction and photoreceptor layer dystrophy. This study serves as proof of concept for the use of zebrafish as a simple, inexpensive model with excellent vision on which further study of LCA-related genes is possible. PMID:22378290

  14. Unique and potent effects of acute ibogaine on zebrafish: the developing utility of novel aquatic models for hallucinogenic drug research.

    PubMed

    Cachat, Jonathan; Kyzar, Evan J; Collins, Christopher; Gaikwad, Siddharth; Green, Jeremy; Roth, Andrew; El-Ounsi, Mohamed; Davis, Ari; Pham, Mimi; Landsman, Samuel; Stewart, Adam Michael; Kalueff, Allan V

    2013-01-01

    An indole alkaloid, ibogaine is the principal psychoactive component of the iboga plant, used by indigenous peoples in West Africa for centuries. Modulating multiple neurotransmitter systems, the drug is a potent hallucinogen in humans, although its psychotropic effects remain poorly understood. Expanding the range of model species is an important strategy for translational neuroscience research. Here we exposed adult zebrafish (Danio rerio) to 10 and 20mg/L of ibogaine, testing them in the novel tank, light-dark box, open field, mirror stimulation, social preference and shoaling tests. In the novel tank test, the zebrafish natural diving response (geotaxis) was reversed by ibogaine, inducing initial top swimming followed by bottom dwelling. Ibogaine also attenuated the innate preference for dark environments (scototaxis) in the light-dark box test. While it did not exert overt locomotor or thigmotaxic responses in the open field test, the drug altered spatiotemporal exploration of novel environment, inducing clear preference of some areas over others. Ibogaine also promoted 'mirror' exploration in the mirror stimulation test, disrupted group cohesion in the shoaling test, and evoked strong coloration responses due to melanophore aggregation, but did not alter brain c-fos expression or whole-body cortisol levels. Overall, our results support the complex pharmacological profile of ibogaine and its high sensitivity in zebrafish models, dose-dependently affecting multiple behavioral domains. While future investigations in zebrafish may help elucidate the mechanisms underlying these unique behavioral effects, our study strongly supports the developing utility of aquatic models in hallucinogenic drug research. High sensitivity of three-dimensional phenotyping approaches applied here to behavioral effects of ibogaine in zebrafish provides further evidence of how 3D reconstructions of zebrafish swimming paths may be useful for high-throughput pharmacological screening.

  15. Inactivation of Myosin Binding Protein C Homolog in Zebrafish as a Model for Human Cardiac Hypertrophy and Diastolic Dysfunction

    PubMed Central

    Chen, Yau‐Hung; Pai, Chiung‐Wen; Huang, Shu‐Wei; Chang, Sheng‐Nan; Lin, Lian‐Yu; Chiang, Fu‐Tien; Lin, Jiunn‐Lee; Hwang, Juey‐Jen; Tsai, Chia‐Ti

    2013-01-01

    Background Sudden cardiac death due to malignant ventricular arrhythmia is a devastating manifestation of cardiac hypertrophy. Sarcomere protein myosin binding protein C is functionally related to cardiac diastolic function and hypertrophy. Zebrafish is a better model to study human electrophysiology and arrhythmia than rodents because of the electrophysiological characteristics similar to those of humans. Methods and Results We established a zebrafish model of cardiac hypertrophy and diastolic dysfunction by genetic knockdown of myosin binding protein C gene (mybpc3) and investigated the electrophysiological phenotypes in this model. We found expression of zebrafish mybpc3 restrictively in the heart and slow muscle, and mybpc3 gene was evolutionally conservative with sequence homology between zebrafish and human mybpc3 genes. Zebrafish with genetic knockdown of mybpc3 by morpholino showed ventricular hypertrophy with increased myocardial wall thickness and diastolic heart failure, manifesting as decreased ventricular diastolic relaxation velocity, pericardial effusion, and dilatation of the atrium. In terms of electrophysiological phenotypes, mybpc3 knockdown fish had a longer ventricular action potential duration and slower ventricular diastolic calcium reuptake, both of which are typical electrophysiological features in human cardiac hypertrophy and heart failure. Impaired calcium reuptake resulted in increased susceptibility to calcium transient alternans and action potential duration alternans, which have been proved to be central to the genesis of malignant ventricular fibrillation and a sensitive marker of sudden cardiac death. Conclusions mybpc3 knockdown in zebrafish recapitulated the morphological, mechanical, and electrophysiological phenotypes of human cardiac hypertrophy and diastolic heart failure. Our study also first demonstrated arrhythmogenic cardiac alternans in cardiac hypertrophy. PMID:24047589

  16. Use of TSHβ:EGFP transgenic zebrafish as a rapid in vivo model for assessing thyroid-disrupting chemicals.

    PubMed

    Ji, Cheng; Jin, Xia; He, Jiangyan; Yin, Zhan

    2012-07-15

    Accumulating evidence indicates that a wide range of chemicals have the ability to interfere with the hypothalamic-pituitary-thyroid (HPT) axis. Novel endpoints should be evaluated in addition to existing methods in order to effectively assess the effects of these chemicals on the HPT axis. Thyroid-stimulating hormone subunit β (TSHβ) plays central regulatory roles in the HPT system. We identified the regulatory region that determines the expression level of zebrafish TSHβ in the anterior pituitary. In the transgenic zebrafish with EGFP driven by the TSHβ promoter, the similar responsive patterns between the expression levels of TSHβ:EGFP and endogenous TSHβ mRNA in the pituitary are observed following treatments with goitrogen chemicals and exogenous thyroid hormones (THs). These results suggest that the TSHβ:EGFP transgenic reporter zebrafish may be a useful alternative in vivo model for the assessment of chemicals interfering with the HPT system.

  17. Binding difference of fipronil with GABAARs in fruitfly and zebrafish: insights from homology modeling, docking, and molecular dynamics simulation studies.

    PubMed

    Zheng, Nan; Cheng, Jiagao; Zhang, Wei; Li, Weihua; Shao, Xusheng; Xu, Zhiping; Xu, Xiaoyong; Li, Zhong

    2014-11-05

    Fipronil, which targets GABAA receptors (GABAARs), is the first phenylpyrazole insecticide widely used in crop protection and public hygiene. However, its high toxicity on fishes greatly limited its applications. In the present study, a series of computational methods including homology modeling, docking, and molecular dynamics simulation studies were integrated to explore the binding difference of fipronil with GABAARs from fruitfly and zebrafish systems. It was found that, in the zebrafish system, the H-bond between 6'Thr and fipronil exerted key effects on the recognition of fipronil, which was absent in the fruitfly system. On the other hand, in the fruitfly system, strong electrostatic interaction between 2'Ala and fipronil was favorable to the binding of fipronil but detrimental to the binding in the zebrafish system. These findings marked the binding difference of fipronil with different GABAARs, which might be helpful in designing selective insecticides against pests instead of fishes.

  18. Nicotinic involvement in memory function in zebrafish.

    PubMed

    Levin, Edward D; Chen, Elaine

    2004-01-01

    Zebrafish are an emerging model for the study of the molecular mechanisms of brain function. To conduct studies of the neural bases of behavior in zebrafish, we must understand the behavioral function of zebrafish and how it is altered by perturbations of brain function. This study determined nicotine actions on memory function in zebrafish. With the methods that we have developed to assess memory in zebrafish using delayed spatial alternation (DSA), we determined the dose effect function of acute nicotine on memory function in zebrafish. As in rodents and primates, low nicotine doses improve memory in zebrafish, while high nicotine doses have diminished effect and can impair memory. This study shows that nicotine affects memory function in zebrafish much like in rats, mice, monkeys and humans. Now, zebrafish can be used to help understand the molecular mechanisms crucial to nicotine effects on memory.

  19. Adult zebrafish intestine resection: a novel model of short bowel syndrome, adaptation, and intestinal stem cell regeneration.

    PubMed

    Schall, K A; Holoyda, K A; Grant, C N; Levin, D E; Torres, E R; Maxwell, A; Pollack, H A; Moats, R A; Frey, M R; Darehzereshki, A; Al Alam, D; Lien, C; Grikscheit, T C

    2015-08-01

    Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation.

  20. RAP-011 improves erythropoiesis in zebrafish model of Diamond-Blackfan anemia through antagonizing lefty1.

    PubMed

    Ear, Jason; Huang, Haigen; Wilson, Tianna; Tehrani, Zahra; Lindgren, Anne; Sung, Victoria; Laadem, Abderrahmane; Daniel, Thomas O; Chopra, Rajesh; Lin, Shuo

    2015-08-13

    Diamond-Blackfan Anemia (DBA) is a bone marrow failure disorder characterized by low red blood cell count. Mutations in ribosomal protein genes have been identified in approximately half of all DBA cases. Corticosteriod therapy and bone marrow transplantation are common treatment options for patients; however, significant risks and complications are associated with these treatment options. Therefore, novel therapeutic approaches are needed for treating DBA. Sotatercept (ACE-011, and its murine ortholog RAP-011) acts as an activin receptor type IIA ligand trap, increasing hemoglobin and hematocrit in pharmacologic models, in healthy volunteers, and in patients with β-thalassemia, by expanding late-stage erythroblasts through a mechanism distinct from erythropoietin. Here, we evaluated the effects of RAP-011 in zebrafish models of RPL11 ribosome deficiency. Treatment with RAP-011 dramatically restored hemoglobin levels caused by ribosome stress. In zebrafish embryos, RAP-011 likely stimulates erythropoietic activity by sequestering lefty1 from erythroid cells. These findings identify lefty1 as a signaling component in the development of erythroid cells and rationalize the use of sotatercept in DBA patients. © 2015 by The American Society of Hematology.

  1. Polymethoxy-1-alkenes from Aphanizomenon ovalisporum Inhibit Vertebrate Development in the Zebrafish (Danio rerio) Embryo Model

    PubMed Central

    Jaja-Chimedza, Asha; Gantar, Miroslav; Gibbs, Patrick D. L.; Schmale, Michael C.; Berry, John P.

    2012-01-01

    Cyanobacteria are recognized producers of a wide array of toxic or otherwise bioactive secondary metabolites. The present study utilized the zebrafish (Danio rerio) embryo as an aquatic animal model of vertebrate development to identify, purify and characterize lipophilic inhibitors of development (i.e., developmental toxins) from an isolate of the freshwater cyanobacterial species, Aphanizomenon ovalisporum.Bioassay-guided fractionation led to the purification, and subsequent chemical characterization, of an apparent homologous series of isotactic polymethoxy-1-alkenes (1–6), including three congeners (4–6) previously identified from the strain, and two variants previously identified from other species (2 and 3), as well as one apparently novel member of the series (1). Five of the PMAs in the series (1–5) were purified in sufficient quantity for comparative toxicological characterization, and toxicity in the zebrafish embryo model was found to generally correlate with relative chain length and/or methoxylation. Moreover, exposure of embryos to a combination of variants indicates an apparent synergistic interaction between the congeners. Although PMAs have been identified previously in cyanobacteria, this is the first report of their apparent toxicity. These results, along with the previously reported presence of the PMAs from several cyanobacterial species, suggest a possibly widespread distribution of the PMAs as toxic secondary metabolites and warrants further chemical and toxicological investigation. PMID:23170087

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

    PubMed

    Stoyek, Matthew R; Quinn, T Alexander; Croll, Roger P; Smith, Frank M

    2016-09-01

    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. Copyright © 2016 the American Physiological Society.

  3. Altered Chondrocyte Differentiation and Extracellular Matrix Homeostasis in a Zebrafish Model for Mucolipidosis II

    PubMed Central

    Flanagan-Steet, Heather; Sias, Christina; Steet, Richard

    2009-01-01

    Mucolipidosis II (ML-II) is a pediatric disorder caused by defects in the biosynthesis of mannose 6-phosphate, the carbohydrate recognition signal responsible for targeting certain acid hydrolases to lysosomes. The mechanisms underlying the developmental defects of ML-II are largely unknown due in part to the lack of suitable animal models. To overcome these limitations, we developed a model for ML-II in zebrafish by inhibiting the expression of N-acetylglucosamine-1-phosphotransferase, the enzyme that initiates mannose 6-phosphate biosynthesis. Morphant embryos manifest craniofacial defects, impaired motility, and abnormal otolith and pectoral fin development. Decreased mannose phosphorylation of several lysosomal glycosidases was observed in morphant lysates, consistent with the reduction in phosphotransferase activity. Investigation of the craniofacial defects in the morphants uncovered striking changes in the timing and localization of both type II collagen and Sox9 expression, suggestive of an accelerated chondrocyte differentiation program. Accumulation of type II collagen was also noted within misshapen cartilage elements at later stages of development. Furthermore, we observed abnormal matrix formation and calcium deposition in morphant otoliths. Collectively, these data provide new insight into the developmental pathology of ML-II and suggest that altered production and/or homeostasis of extracellular matrix proteins are integral to the disease process. These findings highlight the potential of the zebrafish system in studying lysosomal disease pathogenesis. PMID:19834066

  4. Zebrafish as a Model System for Environmental Health Studies in the Grade 9–12 Classroom

    PubMed Central

    Hesselbach, Renee; Carvan, Michael John; Goldberg, Barbara; Berg, Craig A.; Petering, David H.

    2014-01-01

    Abstract Developing zebrafish embryos were used as a model system for high school students to conduct scientific investigations that reveal features of normal development and to test how different environmental toxicants impact the developmental process. The primary goal of the module was to engage students from a wide range of socio-economic backgrounds, with particular focus on underserved inner-city high schools, in inquiry-based learning and hands-on experimentation. In addition, the module served as a platform for both teachers and students to design additional inquiry-based experiments. In this module, students spawned adult zebrafish to generate developing embryos, exposed the embryos to various toxicants, then gathered, and analyzed data obtained from control and experimental embryos. The module provided a flexible, experimental framework for students to test the effects of numerous environmental toxicants, such as ethanol, caffeine, and nicotine, on the development of a model vertebrate organism. Students also observed the effects of dose on experimental outcomes. From observations of the effects of the chemical agents on vertebrate embryos, students drew conclusions on how these chemicals could impact human development and health. Results of pre-tests and post-tests completed by participating students indicate statistically significant changes in awareness of the impact of environmental agents on fish and human beings In addition, the program's evaluator concluded that participation in the module resulted in significant changes in the attitude of students and teachers toward science in general and environmental health in particular. PMID:24941301

  5. Ethanol exposure alters zebrafish development: a novel model of fetal alcohol syndrome.

    PubMed

    Bilotta, Joseph; Barnett, Jalynn A; Hancock, Laura; Saszik, Shannon

    2004-01-01

    Prenatal exposure to alcohol has been shown to produce the overt physical and behavioral symptoms known as fetal alcohol syndrome (FAS) in humans. Also, it is believed that low concentrations and/or short durations of alcohol exposure can produce more subtle effects. The purpose of this study was to investigate the effects of embryonic ethanol exposure on the zebrafish (Danio rerio) in order to determine whether this species is a viable animal model for studying FAS. Fertilized embryos were reared in varying concentrations of ethanol (1.5% and 2.9%) and exposure times (e.g., 0-8, 6-24, 12-24, and 48-72 h postfertilization; hpf); anatomical measures including eye diameter and heart rate were compared across groups. Results found that at the highest concentration of ethanol (2.9%), there were more abnormal physical distortions and significantly higher mortality rates than any other group. Embryos exposed to ethanol for a shorter duration period (0-8 hpf) at a concentration of 1.5% exhibited more subtle effects such as significantly smaller eye diameter and lower heart rate than controls. These results indicate that embryonic alcohol exposure affects external and internal physical development and that the severity of these effects is a function of both the amount of ethanol and the timing of ethanol exposure. Thus, the zebrafish represents a useful model for examining basic questions about the effects of embryonic exposure to ethanol on development.

  6. MYBPC1 mutations impair skeletal muscle function in zebrafish models of arthrogryposis.

    PubMed

    Ha, Kyungsoo; Buchan, Jillian G; Alvarado, David M; McCall, Kevin; Vydyanath, Anupama; Luther, Pradeep K; Goldsmith, Matthew I; Dobbs, Matthew B; Gurnett, Christina A

    2013-12-15

    Myosin-binding protein C1 (MYBPC1) is an abundant skeletal muscle protein that is expressed predominantly in slow-twitch muscle fibers. Human MYBPC1 mutations are associated with distal arthrogryposis type 1 and lethal congenital contracture syndrome type 4. As MYBPC1 function is incompletely understood, the mechanism by which human mutations result in contractures is unknown. Here, we demonstrate using antisense morpholino knockdown, that mybpc1 is required for embryonic motor activity and survival in a zebrafish model of arthrogryposis. Mybpc1 morphant embryos have severe body curvature, cardiac edema, impaired motor excitation and are delayed in hatching. Myofibril organization is selectively impaired in slow skeletal muscle and sarcomere numbers are greatly reduced in mybpc1 knockdown embryos, although electron microscopy reveals normal sarcomere structure. To evaluate the effects of human distal arthrogryposis mutations, mybpc1 mRNAs containing the corresponding human W236R and Y856H MYBPC1 mutations were injected into embryos. Dominant-negative effects of these mutations were suggested by the resultant mild bent body curvature, decreased motor activity, as well as impaired overall survival compared with overexpression of wild-type RNA. These results demonstrate a critical role for mybpc1 in slow skeletal muscle development and establish zebrafish as a tractable model of human distal arthrogryposis.

  7. MYBPC1 mutations impair skeletal muscle function in zebrafish models of arthrogryposis

    PubMed Central

    Ha, Kyungsoo; Buchan, Jillian G.; Alvarado, David M.; Mccall, Kevin; Vydyanath, Anupama; Luther, Pradeep K.; Goldsmith, Matthew I.; Dobbs, Matthew B.; Gurnett, Christina A.

    2013-01-01

    Myosin-binding protein C1 (MYBPC1) is an abundant skeletal muscle protein that is expressed predominantly in slow-twitch muscle fibers. Human MYBPC1 mutations are associated with distal arthrogryposis type 1 and lethal congenital contracture syndrome type 4. As MYBPC1 function is incompletely understood, the mechanism by which human mutations result in contractures is unknown. Here, we demonstrate using antisense morpholino knockdown, that mybpc1 is required for embryonic motor activity and survival in a zebrafish model of arthrogryposis. Mybpc1 morphant embryos have severe body curvature, cardiac edema, impaired motor excitation and are delayed in hatching. Myofibril organization is selectively impaired in slow skeletal muscle and sarcomere numbers are greatly reduced in mybpc1 knockdown embryos, although electron microscopy reveals normal sarcomere structure. To evaluate the effects of human distal arthrogryposis mutations, mybpc1 mRNAs containing the corresponding human W236R and Y856H MYBPC1 mutations were injected into embryos. Dominant-negative effects of these mutations were suggested by the resultant mild bent body curvature, decreased motor activity, as well as impaired overall survival compared with overexpression of wild-type RNA. These results demonstrate a critical role for mybpc1 in slow skeletal muscle development and establish zebrafish as a tractable model of human distal arthrogryposis. PMID:23873045

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

    PubMed Central

    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

  9. Pten mediates Myc oncogene dependence in a conditional zebrafish model of T cell acute lymphoblastic leukemia

    PubMed Central

    Grebliunaite, Ruta; Feng, Hui; Kozakewich, Elena; Zhu, Shizhen; Guo, Feng; Payne, Elspeth; Mansour, Marc; Dahlberg, Suzanne E.; Neuberg, Donna S.; den Hertog, Jeroen; Prochownik, Edward V.; Testa, Joseph R.; Harris, Marian; Kanki, John P.

    2011-01-01

    The MYC oncogenic transcription factor is overexpressed in most human cases of T cell acute lymphoblastic leukemia (T-ALL), often downstream of mutational NOTCH1 activation. Genetic alterations in the PTEN–PI3K–AKT pathway are also common in T-ALL. We generated a conditional zebrafish model of T-ALL in which 4-hydroxytamoxifen (4HT) treatment induces MYC activation and disease, and withdrawal of 4HT results in T-ALL apoptosis and tumor regression. However, we found that loss-of-function mutations in zebrafish pten genes, or expression of a constitutively active Akt2 transgene, rendered tumors independent of the MYC oncogene and promoted disease progression after 4HT withdrawal. Moreover, MYC suppresses pten mRNA levels, suggesting that Akt pathway activation downstream of MYC promotes tumor progression. Our findings indicate that Akt pathway activation is sufficient for tumor maintenance in this model, even after loss of survival signals driven by the MYC oncogene. PMID:21727187

  10. Zebrafish as a model system for environmental health studies in the grade 9-12 classroom.

    PubMed

    Tomasiewicz, Henry G; Hesselbach, Renee; Carvan, Michael John; Goldberg, Barbara; Berg, Craig A; Petering, David H

    2014-08-01

    Developing zebrafish embryos were used as a model system for high school students to conduct scientific investigations that reveal features of normal development and to test how different environmental toxicants impact the developmental process. The primary goal of the module was to engage students from a wide range of socio-economic backgrounds, with particular focus on underserved inner-city high schools, in inquiry-based learning and hands-on experimentation. In addition, the module served as a platform for both teachers and students to design additional inquiry-based experiments. In this module, students spawned adult zebrafish to generate developing embryos, exposed the embryos to various toxicants, then gathered, and analyzed data obtained from control and experimental embryos. The module provided a flexible, experimental framework for students to test the effects of numerous environmental toxicants, such as ethanol, caffeine, and nicotine, on the development of a model vertebrate organism. Students also observed the effects of dose on experimental outcomes. From observations of the effects of the chemical agents on vertebrate embryos, students drew conclusions on how these chemicals could impact human development and health. Results of pre-tests and post-tests completed by participating students indicate statistically significant changes in awareness of the impact of environmental agents on fish and human beings In addition, the program's evaluator concluded that participation in the module resulted in significant changes in the attitude of students and teachers toward science in general and environmental health in particular.

  11. Cholinergic System and Oxidative Stress Changes in the Brain of a Zebrafish Model Chronically Exposed to Ethanol.

    PubMed

    Agostini, Jotele Fontana; Toé, Helena Cristina Zuehl Dal; Vieira, Karine Medeiros; Baldin, Samira Leila; Costa, Naithan Ludian Fernandes; Cruz, Carolina Uribe; Longo, Larisse; Machado, Marcel Marcos; da Silveira, Themis Reverbel; Schuck, Patrícia Fernanda; Rico, Eduardo Pacheco

    2017-09-23

    Ethanol is a widely used drug, and excess or even moderate consumption of ethanol is associated with changes in several neurotransmitter systems, including the cholinergic system. The incidence of alcoholic dementia and its insults are well supported by multiple studies, although the mechanisms of neurotoxicity are still poorly understood. Considering that zebrafish have a complete central nervous system (CNS) and that several signaling systems have already been identified in zebrafish, this neurotoxicological model has become useful. In the present study, we investigated the long-term effects of ethanol consumption on the cholinergic system, on oxidative stress, and on inflammatory parameters in the zebrafish brain. Animals were exposed to 0.5% (v/v) ethanol for 7, 14, and 28 days. Ethanol inhibited choline acetyltransferase activity after 7 and 14 days but not after 28 days. Acetylcholinesterase activity did not change after any of the exposure periods. When compared to the control group, thiobarbituric acid reactive species and dichlorodihydrofluorescein levels were increased after chronic ethanol exposure. Antioxidant activity promoted by the CAT/SOD ratio was altered after chronic ethanol exposure, suggesting that EtOH can induce oxidative damage in the zebrafish brain. In contrast, nitrate and nitrite levels and sulfhydryl content were not altered. Ethanol did not modify gene expression of the inflammatory cytokines il-1b, il-10, or tnf-α in the zebrafish brain. Therefore, the cholinergic system and the oxidative balance were targeted by chronic ethanol toxicity. This neurochemical regulatory mechanism may play an important role in understanding the effects of long-term ethanol consumption and tolerance in zebrafish model studies.

  12. Technology with High-Speed Movies to Analyze the Movement of Internal Organs in Medaka

    NASA Astrophysics Data System (ADS)

    Watanabe-Asaka, Tomomi; Niihori, Maki; Terada, Masahiro; Oda, Shoji; Iwasaki, Ken-Ichi; Sudoh, Masamichi; Yamada, Shin; Ohshima, Hiroshi; Mukai, Chiaki

    Living organisms are always exposed and respond to various stresses from the external world - the environment, such as temperature, gravity, radiation or circadian. Understanding and addressing the effects of the environment on human health is a major issue. To clarify this issue, we are studying both human and medaka. Medaka is a good model organism to verify the effects of the space environment for their features including their short life cycle, productivity, mapped whole genome sequences, and transparency even in adults. We are trying to evaluate the heartbeat using transparent medaka with live imaging. Despite the importance of functions of internal organs, its observation has been difficult. Imaging technologies has developed remarkably in a decade. With the retirement of the space shuttle, experimental procedures without sample collection will be required. We established an approach to acquire the images and the methodology of the analysis from high-speed movies. We are subsequently going to introduce a method of verifying the movement of internal organs in medaka experiments using high-speed movies.

  13. Proteasome inhibition in medaka brain induces the features of Parkinson's disease.

    PubMed

    Matsui, Hideaki; Ito, Hidefumi; Taniguchi, Yoshihito; Inoue, Haruhisa; Takeda, Shunichi; Takahashi, Ryosuke

    2010-10-01

    Recent findings suggest that a defect in the ubiquitin-proteasome system plays an important role in the pathogenesis of Parkinson's disease (PD). A previous report (McNaught et al. 2004) demonstrated that rats systemically injected with proteasome inhibitors exhibited PD-like clinical symptoms and pathology. However, because these findings have not been consistently replicated, this model is not commonly used to study PD. We used medaka fish to test the effect of systemic administration of proteasome inhibitors because of the high level of accessibility of the cerebrospinal fluid in fish. We injected lactacystin or epoxomicin into the CSF of medaka. With proteasome inhibition in the medaka brain, selective dopaminergic and noradrenergic cell loss was observed. Furthermore, treated fish exhibited reduced spontaneous movement. Treatment with proteasome inhibitors also induced the formation of inclusion bodies resembling Lewy bodies, which are characteristic of PD. Treatment with 6-OHDA also induced dopaminergic cell loss but did not produce inclusion bodies. These findings in medaka are consistent with previous results reporting that non-selective proteasome inhibition replicates the cardinal features of PD: locomotor dysfunction, selective dopaminergic cell loss, and inclusion body formation.

  14. Discovery and functional characterization of novel miRNAs in the marine medaka Oryzias melastigma.

    PubMed

    Li, Jing-Woei; Lin, Xiao; Tse, Anna; Cheung, Angela; Chan, Ting Fung; Kong, Richard Yuen Chong; Lai, Keng Po; Wu, Rudolf Shiu Sun

    2016-06-01

    The marine medaka Oryzias melastigma has often been used as a marine fish model to investigate the biological responses to environmental stresses and pollutants in marine environments. miRNAs are post-transcriptional regulators of many biological processes in a variety of organisms, and have been shown to be affected by environmental stresses, but the novel miRNA profile of marine medaka has not been reported. Using both genome and small RNA sequencings coupled with different bioinformatics analyses, we have discovered 58, 82, 234, and 201 unannotated miRNAs in the brain, liver, ovary and testis tissues of marine medaka, respectively. Furthermore, these novel miRNAs were found to target genes with tissue-specific roles such as neuron development and synaptic transmission in the brain, glucose and fat metabolism in the liver and steroidogenesis in the gonads. We here report, for the first time, novel miRNA profile of marine medaka, which will provide a foundation for future biomarkers and transgenerational studies for the assessment of environmental stresses and pollutions in the marine environments. In a boarder context, our data will provide novel insight into our knowledge of miRNome and miR research.

  15. Principal function of mineralocorticoid signaling suggested by constitutive knockout of the mineralocorticoid receptor in medaka fish

    PubMed Central

    Sakamoto, Tatsuya; Yoshiki, Madoka; Takahashi, Hideya; Yoshida, Masayuki; Ogino, Yukiko; Ikeuchi, Toshitaka; Nakamachi, Tomoya; Konno, Norifumi; Matsuda, Kouhei; Sakamoto, Hirotaka

    2016-01-01

    As in osmoregulation, mineralocorticoid signaling is implicated in the control of brain-behavior actions. Nevertheless, the understanding of this role is limited, partly due to the mortality of mineralocorticoid receptor (MR)-knockout (KO) mice due to impaired Na+ reabsorption. In teleost fish, a distinct mineralocorticoid system has only been identified recently. Here, we generated a constitutive MR-KO medaka as the first adult-viable MR-KO animal, since MR expression is modest in osmoregulatory organs but high in the brain of adult medaka as for most teleosts. Hyper- and hypo-osmoregulation were normal in MR-KO medaka. When we studied the behavioral phenotypes based on the central MR localization, however, MR-KO medaka failed to track moving dots despite having an increase in acceleration of swimming. These findings reinforce previous results showing a minor role for mineralocorticoid signaling in fish osmoregulation, and provide the first convincing evidence that MR is required for normal locomotor activity in response to visual motion stimuli, but not for the recognition of these stimuli per se. We suggest that MR potentially integrates brain-behavioral and visual responses, which might be a conserved function of mineralocorticoid signaling through vertebrates. Importantly, this fish model allows for the possible identification of novel aspects of mineralocorticoid signaling. PMID:27897263

  16. Establishing Zebrafish as a Novel Exercise Model: Swimming Economy, Swimming-Enhanced Growth and Muscle Growth Marker Gene Expression

    PubMed Central

    Rovira, Mireia; Brittijn, Sebastiaan A.; Burgerhout, Erik; van den Thillart, Guido E. E. J. M.; Spaink, Herman P.; Planas, Josep V.

    2010-01-01

    Background Zebrafish has been largely accepted as a vertebrate multidisciplinary model but its usefulness as a model for exercise physiology has been hampered by the scarce knowledge on its swimming economy, optimal swimming speeds and cost of transport. Therefore, we have performed individual and group-wise swimming experiments to quantify swimming economy and to demonstrate the exercise effects on growth in adult zebrafish. Methodology/Principal Findings Individual zebrafish (n = 10) were able to swim at a critical swimming speed (Ucrit) of 0.548±0.007 m s−1 or 18.0 standard body lengths (BL) s−1. The optimal swimming speed (Uopt) at which energetic efficiency is highest was 0.396±0.019 m s−1 (13.0 BL s−1) corresponding to 72.26±0.29% of Ucrit. The cost of transport at optimal swimming speed (COTopt) was 25.23±4.03 µmol g−1 m−1. A group-wise experiment was conducted with zebrafish (n = 83) swimming at Uopt for 6 h day−1 for 5 days week−1 for 4 weeks vs. zebrafish (n = 84) that rested during this period. Swimming zebrafish increased their total body length by 5.6% and body weight by 41.1% as compared to resting fish. For the first time, a highly significant exercise-induced growth is demonstrated in adult zebrafish. Expression analysis of a set of muscle growth marker genes revealed clear regulatory roles in relation to swimming-enhanced growth for genes such as growth hormone receptor b (ghrb), insulin-like growth factor 1 receptor a (igf1ra), troponin C (stnnc), slow myosin heavy chain 1 (smyhc1), troponin I2 (tnni2), myosin heavy polypeptide 2 (myhz2) and myostatin (mstnb). Conclusions/Significance From the results of our study we can conclude that zebrafish can be used as an exercise model for enhanced growth, with implications in basic, biomedical and applied sciences, such as aquaculture. PMID:21217817

  17. Heritable T Cell Malignancy Models Established in a Zebrafish Phenotypic Screen

    PubMed Central

    Frazer, J. Kimble; Meeker, Nathan; Rudner, Lynnie; Bradley, Diana F.; Smith, Alexandra C. H.; Demarest, Bradley; Joshi, Deepa; Locke, Erin E.; Hutchinson, Sarah A.; Tripp, Sheryl; Perkins, Sherrie L.; Trede, Nikolaus S.

    2009-01-01

    T cell neoplasias are common in pediatric oncology, and include acute lymphoblastic leukemia (T-ALL) and lymphoblastic lymphoma (T-LBL). These cancers have worse prognoses than their B cell counterparts, and their treatments carry significant morbidity. While many pediatric malignancies have characteristic translocations, most T lymphocyte-derived diseases lack cytogenetic hallmarks. Lacking these informative lesions, insight into their molecular pathogenesis is less complete. Although dysregulation of the NOTCH1 pathway occurs in a substantial fraction of cases, many other genetic lesions of T cell malignancy have not yet been determined. To address this deficiency, we pioneered a phenotype-driven forward-genetic screen in zebrafish (Danio rerio). Using transgenic fish with T lymphocyte-specific expression of enhanced green fluorescent protein (EGFP), we performed chemical mutagenesis, screened animals for GFP+ tumors, and identified multiple lines with a heritable predisposition to T cell malignancy. In each line, patterns of infiltration and morphologic appearance resembled human T-ALL and T-LBL. T cell receptor analyses confirmed their clonality. Malignancies were transplantable and contained leukemia-initiating cells (LIC), like their human correlates. In summary, we have identified multiple zebrafish mutants that recapitulate human T cell neoplasia and show heritable transmission. These vertebrate models provide new genetic platforms for the study of these important human cancers. PMID:19516274

  18. Defective neural crest migration revealed by a Zebrafish model of Alx1-related frontonasal dysplasia.

    PubMed

    Dee, Chris T; Szymoniuk, Christoph R; Mills, Peter E D; Takahashi, Tokiharu

    2013-01-15

    Frontonasal dysplasia (FND) refers to a class of midline facial malformations caused by abnormal development of the facial primordia. The term encompasses a spectrum of severities but characteristic features include combinations of ocular hypertelorism, malformations of the nose and forehead and clefting of the facial midline. Several recent studies have drawn attention to the importance of Alx homeobox transcription factors during craniofacial development. Most notably, loss of Alx1 has devastating consequences resulting in severe orofacial clefting and extreme microphthalmia. In contrast, mutations of Alx3 or Alx4 cause milder forms of FND. Whilst Alx1, Alx3 and Alx4 are all known to be expressed in the facial mesenchyme of vertebrate embryos, little is known about the function of these proteins during development. Here, we report the establishment of a zebrafish model of Alx-related FND. Morpholino knock-down of zebrafish alx1 expression causes a profound craniofacial phenotype including loss of the facial cartilages and defective ocular development. We demonstrate for the first time that Alx1 plays a crucial role in regulating the migration of cranial neural crest (CNC) cells into the frontonasal primordia. Abnormal neural crest migration is coincident with aberrant expression of foxd3 and sox10, two genes previously suggested to play key roles during neural crest development, including migration, differentiation and the maintenance of progenitor cells. This novel function is specific to Alx1, and likely explains the marked clinical severity of Alx1 mutation within the spectrum of Alx-related FND.

  19. Caffeic acid and hydroxytyrosol have anti-obesogenic properties in zebrafish and rainbow trout models

    PubMed Central

    Lutfi, Esmail; Babin, Patrick J.; Gutiérrez, Joaquim; Capilla, Encarnación

    2017-01-01

    Some natural products, known sources of bioactive compounds with a wide range of properties, may have therapeutic values in human health and diseases, as well as agronomic applications. The effect of three compounds of plant origin with well-known dietary antioxidant properties, astaxanthin (ATX), caffeic acid (CA) and hydroxytyrosol (HT), on zebrafish (Danio rerio) larval adiposity and rainbow trout (Onchorynchus mykiss) adipocytes was assessed. The zebrafish obesogenic test (ZOT) demonstrated the anti-obesogenic activity of CA and HT. These compounds were able to counteract the obesogenic effect produced by the peroxisome proliferator-activated receptor gamma (PPARγ) agonist, rosiglitazone (RGZ). CA and HT suppressed RGZ-increased PPARγ protein expression and lipid accumulation in primary-cultured rainbow trout adipocytes. HT also significantly reduced plasma triacylglycerol concentrations, as well as mRNA levels of the fasn adipogenic gene in the adipose tissue of HT-injected rainbow trout. In conclusion, in vitro and in vivo approaches demonstrated the anti-obesogenic potential of CA and HT on teleost fish models that may be relevant for studying their molecular mode of action. Further studies are required to evaluate the effect of these bioactive components as food supplements for modulating adiposity in farmed fish. PMID:28570659

  20. Interaction of mercury and selenium in the larval stage zebrafish vertebrate model.

    PubMed

    MacDonald, Tracy C; Korbas, Malgorzata; James, Ashley K; Sylvain, Nicole J; Hackett, Mark J; Nehzati, Susan; Krone, Patrick H; George, Graham N; Pickering, Ingrid J

    2015-08-01

    The compounds of mercury can be more toxic than those of any other non-radioactive heavy element. Despite this, environmental mercury pollution and human exposure to mercury are widespread, and are increasing. While the unusual ability of selenium to cancel the toxicity of mercury compounds has been known for nearly five decades, only recently have some aspects of the molecular mechanisms begun to be understood. We report herein a study of the interaction of mercury and selenium in the larval stage zebrafish, a model vertebrate system, using X-ray fluorescence imaging. Exposure of larval zebrafish to inorganic mercury shows nano-scale structures containing co-localized mercury and selenium. No such co-localization is seen with methylmercury exposure under similar conditions. Micro X-ray absorption spectra support the hypothesis that the co-localized deposits are most likely comprised of highly insoluble mixed chalcogenide HgSxSe(1-x) where x is 0.4-0.9, probably with the cubic zincblende structure.

  1. The in vitro zebrafish heart as a model to investigate the chronotropic effects of vapor anesthetics.

    PubMed

    Stoyek, Matthew R; Schmidt, Michael K; Wilfart, Florentin M; Croll, Roger P; Smith, Frank M

    2017-09-06

    In addition to their intended clinical actions, all general anesthetic agents in common use have detrimental intra- and post-surgical side effects on organs and systems including the heart. The major cardiac side effect of anesthesia is bradycardia, which increases the probability of insufficient systemic perfusion during surgery. These side effects also occur in all vertebrate species so far examined, but the underlying mechanisms are not clear. The zebrafish heart is a powerful model for studying cardiac electrophysiology, employing the same pacemaker system and neural control as do mammalian hearts. In this study isolated zebrafish hearts were significantly bradycardic during exposure to the vapor anesthetics sevoflurane (SEVO), desflurane (DES) and isoflurane (ISO). Bradycardia induced by DES and ISO continued during pharmacological blockade of the intracardiac portion of the autonomic nervous system, but the chronotropic effect of SEVO was eliminated during blockade. Bradycardia evoked by vagosympathetic nerve stimulation was augmented during DES and ISO exposure; nerve stimulation during SEVO exposure had no effect. Together these results support the hypothesis that the cardiac chronotropic effect of SEVO occurs via a neurally mediated mechanism while DES and ISO act directly upon cardiac pacemaker cells via an as yet unknown mechanism. Copyright © 2017, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.

  2. Prey capture in zebrafish larvae serves as a model to study cognitive functions

    PubMed Central

    Muto, Akira; Kawakami, Koichi

    2013-01-01

    Prey capture in zebrafish larvae is an innate behavior which can be observed as early as 4~days postfertilization, the day when they start to swim. This simple behavior apparently involves several neural processes including visual perception, recognition, decision-making, and motor control, and, therefore, serves as a good model system to study cognitive functions underlying natural behaviors in vertebrates. Recent progresses in imaging techniques provided us with a unique opportunity to image neuronal activity in the brain of an intact fish in real-time while the fish perceives a natural prey, paramecium. By expanding this approach, it would be possible to image entire brain areas at a single-cell resolution in real-time during prey capture, and identify neuronal circuits important for cognitive functions. Further, activation or inhibition of those neuronal circuits with recently developed optogenetic tools or neurotoxins should shed light on their roles. Thus, we will be able to explore the prey capture in zebrafish larvae more thoroughly at cellular levels, which should establish a basis of understanding of the cognitive function in vertebrates. PMID:23781176

  3. Analysis of RNAseq datasets from a comparative infectious disease zebrafish model using GeneTiles bioinformatics.

    PubMed

    Veneman, Wouter J; de Sonneville, Jan; van der Kolk, Kees-Jan; Ordas, Anita; Al-Ars, Zaid; Meijer, Annemarie H; Spaink, Herman P

    2015-03-01

    We present a RNA deep sequencing (RNAseq) analysis of a comparison of the transcriptome responses to infection of zebrafish larvae with Staphylococcus epidermidis and Mycobacterium marinum bacteria. We show how our developed GeneTiles software can improve RNAseq analysis approaches by more confidently identifying a large set of markers upon infection with these bacteria. For analysis of RNAseq data currently, software programs such as Bowtie2 and Samtools are indispensable. However, these programs that are designed for a LINUX environment require some dedicated programming skills and have no options for visualisation of the resulting mapped sequence reads. Especially with large data sets, this makes the analysis time consuming and difficult for non-expert users. We have applied the GeneTiles software to the analysis of previously published and newly obtained RNAseq datasets of our zebrafish infection model, and we have shown the applicability of this approach also to published RNAseq datasets of other organisms by comparing our data with a published mammalian infection study. In addition, we have implemented the DEXSeq module in the GeneTiles software to identify genes, such as glucagon A, that are differentially spliced under infection conditions. In the analysis of our RNAseq data, this has led to the possibility to improve the size of data sets that could be efficiently compared without using problem-dedicated programs, leading to a quick identification of marker sets. Therefore, this approach will also be highly useful for transcriptome analyses of other organisms for which well-characterised genomes are available.

  4. A zebrafish melanoma model reveals emergence of neural crest identity during melanoma initiation

    PubMed Central

    Kaufman, Charles K.; Mosimann, Christian; Fan, Zi Peng; Yang, Song; Thomas, Andrew; Ablain, Julien; Tan, Justin L.; Fogley, Rachel D.; van Rooijen, Ellen; Hagedorn, Elliott; Ciarlo, Christie; White, Richard; Matos, Dominick; Puller, Ann-Christin; Santoriello, Cristina; Liao, Eric; Young, Richard A.; Zon, Leonard I.

    2016-01-01

    The “cancerized field” concept posits that cells in a given tissue share an oncogenic mutation or insult and are thus cancer-prone, yet only discreet clones within the field initiate tumors. Nearly all benign nevi carry oncogenic BRAFV600E mutations, but they only rarely become melanoma. The zebrafish crestin gene is expressed embryonically in neural crest progenitors (NCP’s) and is specifically re-expressed in melanoma. We show by live imaging of transgenic zebrafish crestin reporters that, within a cancerized field (BRAFV600E-mutant; p53-deficient), a single melanocyte reactivates the NCP state, and this establishes that a fate change occurs at melanoma initiation in this model. We show the crestin element is regulated by NCP transcription factors, including sox10. Forced sox10 overexpression in melanocytes accelerated melanoma formation, consistent with activation of a NCP gene signature and super-enhancers leading to melanoma. Our work highlights the importance of NCP state reemergence as a key event in melanoma initiation. PMID:26823433

  5. Dietary sodium propionate affects mucosal immune parameters, growth and appetite related genes expression: Insights from zebrafish model.

    PubMed

    Hoseinifar, Seyed Hossein; Safari, Roghieh; Dadar, Maryam

    2017-03-01

    Propionate is a short-chain fatty acid (SCFA) that improves physiological and pathophysiological properties. However, there is limited information available about the effects of SCFAs on mucosal immune parameters as well as growth and appetite related genes expression. The aim of the present study was to evaluate the effect of sodium propionate (SP) intake on the mucosal immune parameters, growth and appetite related genes expression using zebrafish (Danio rerio) as model organism. Zebrafish fed control or diet supplemented with different levels (0.5, 1 and 2%) of SP for 8weeks. At the end of feeding trial, the expression of the key genes related to growth and appetite (GH, IGF1, MYSTN and Ghrl) was evaluated. Also, mucosal immune parameters (Total Ig, lysozyme and protease activity) were studied in skin mucus of zebrafish. The results showed that dietary administration of SP significantly (P<0.05) up-regulated the expression of GH, IGF1 and down-regulated MYSTN gene. Also, feeding zebrafish with SP supplemented diet significantly increased appetite related gene expression (P<0.05) with a more pronounced effect in higher inclusion levels. Compared with control group, the expression of appetite related gene (Ghrl) was remarkably (P<0.05) higher in SP fed zebrafish. Also, elevated mucosal immune parameters was observed in zebrafish fed SP supplemented diet. The present results revealed beneficial effects of dietary SP on mucosal immune response and growth and appetite related genes expression. These results also highlighted the potential use of SP as additive in human diets. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Retinoic acid expands the evolutionarily reduced dentition of zebrafish

    PubMed Central

    Seritrakul, Pawat; Samarut, Eric; Lama, Tenzing T. S.; Gibert, Yann; Laudet, Vincent; Jackman, William R.

    2012-01-01

    Zebrafish lost anterior teeth during evolution but retain a posterior pharyngeal dentition that requires retinoic acid (RA) cell-cell signaling for its development. The purposes of this study were to test the sufficiency of RA to induce tooth development and to assess its role in evolution. We found that exposure of embryos to exogenous RA induces a dramatic anterior expansion of the number of pharyngeal teeth that later form and shifts anteriorly the expression patterns of genes normally expressed in the posterior tooth-forming region, such as pitx2 and dlx2b. After RA exposure, we also observed a correlation between cartilage malformations and ectopic tooth induction, as well as abnormal cranial neural crest marker gene expression. Additionally, we observed that the RA-induced zebrafish anterior teeth resemble in pattern and number the dentition of fish species that retain anterior pharyngeal teeth such as medaka but that medaka do not express the aldh1a2 RA-synthesizing enzyme in tooth-forming regions. We conclude that RA is sufficient to induce anterior ectopic tooth development in zebrafish where teeth were lost in evolution, potentially by altering neural crest cell development, and that changes in the location of RA synthesis correlate with evolutionary changes in vertebrate dentitions.—Seritrakul, P., Samarut, E., Lama, T. T. S., Gibert, Y., Laudet, V., Jackman, W. R. Retinoic acid expands the evolutionarily reduced dentition of zebrafish. PMID:22942074

  7. Efficient targeted mutagenesis in medaka using custom-designed transcription activator-like effector nucleases.

    PubMed

    Ansai, Satoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Ariga, Hiroyoshi; Uemura, Norihito; Takahashi, Ryosuke; Kinoshita, Masato

    2013-03-01

    Transcription activator-like effector nucleases (TALENs) have become powerful tools for targeted genome editing. Here we demonstrate efficient targeted mutagenesis in medaka (Oryzias latipes), which serves as an excellent vertebrate model for genetics and genomics. We designed and constructed a pair of TALENs targeting the medaka DJ-1 gene, a homolog of human DJ-1 (PARK7). These TALENs induced a number of insertions and deletions in the injected embryos with extremely high efficiency. This induction of mutations occurred in a dose-dependent manner. All screened G0 fish injected with the TALENs transmitted the TALEN-induced mutations to the next generation with high efficiency (44-100%). We also confirmed that these TALENs induced site-specific mutations because none of the mutations were found at potential off-target sites. In addition, the DJ-1 protein was lost in DJ-1(Δ7/Δ7) fish that carried a TALEN-induced frameshift mutation in both alleles. We also investigated the effect of the N- and C-terminal regions of the transcription activator-like (TAL) effector domain on the gene-disrupting activity of DJ1-TALENs and found that 287 amino acids at the N terminus and 63 amino acids at the C terminus of the TAL domain exhibited the highest disrupting activity in the injected embryos. Our results suggest that TALENs enable us to rapidly and efficiently establish knockout medaka strains. This is the first report of targeted mutagenesis in medaka using TALENs. The TALEN technology will expand the potential of medaka as a model system for genetics and genomics.

  8. Efficient Targeted Mutagenesis in Medaka Using Custom-Designed Transcription Activator-Like Effector Nucleases

    PubMed Central

    Ansai, Satoshi; Sakuma, Tetsushi; Yamamoto, Takashi; Ariga, Hiroyoshi; Uemura, Norihito; Takahashi, Ryosuke; Kinoshita, Masato

    2013-01-01

    Transcription activator-like effector nucleases (TALENs) have become powerful tools for targeted genome editing. Here we demonstrate efficient targeted mutagenesis in medaka (Oryzias latipes), which serves as an excellent vertebrate model for genetics and genomics. We designed and constructed a pair of TALENs targeting the medaka DJ-1 gene, a homolog of human DJ-1 (PARK7). These TALENs induced a number of insertions and deletions in the injected embryos with extremely high efficiency. This induction of mutations occurred in a dose-dependent manner. All screened G0 fish injected with the TALENs transmitted the TALEN-induced mutations to the next generation with high efficiency (44–100%). We also confirmed that these TALENs induced site-specific mutations because none of the mutations were found at potential off-target sites. In addition, the DJ-1 protein was lost in DJ-1Δ7/Δ7 fish that carried a TALEN-induced frameshift mutation in both alleles. We also investigated the effect of the N- and C-terminal regions of the transcription activator-like (TAL) effector domain on the gene-disrupting activity of DJ1-TALENs and found that 287 amino acids at the N terminus and 63 amino acids at the C terminus of the TAL domain exhibited the highest disrupting activity in the injected embryos. Our results suggest that TALENs enable us to rapidly and efficiently establish knockout medaka strains. This is the first report of targeted mutagenesis in medaka using TALENs. The TALEN technology will expand the potential of medaka as a model system for genetics and genomics. PMID:23288935

  9. Leadership emergence in a data-driven model of zebrafish shoals with speed modulation

    NASA Astrophysics Data System (ADS)

    Zienkiewicz, A.; Barton, D. A. W.; Porfiri, M.; Di Bernardo, M.

    2015-11-01

    Models of collective animal motion can greatly aid in the design and interpretation of behavioural experiments that seek to unravel, isolate, and manipulate the determinants of leader-follower relationships. Here, we develop an initial model of zebrafish social behaviour, which accounts for both speed and angular velocity regulatory interactions among conspecifics. Using this model, we analyse the macroscopic observables of small shoals influenced by an "informed" agent, showing that leaders which actively modulate their speed with respect to their neighbours can entrain and stabilise collective dynamics of the naïve shoal. Supplementary material in the form of two mp4 files available from the Journal web page at http://dx.doi.org/10.1140/epjst/e2015-50093-5

  10. Acute stress disrupts performance of zebrafish in the cued and spatial memory tests: the utility of fish models to study stress-memory interplay.

    PubMed

    Gaikwad, Siddharth; Stewart, Adam; Hart, Peter; Wong, Keith; Piet, Valerie; Cachat, Jonathan; Kalueff, Allan V

    2011-06-01

    The zebrafish (Danio rerio) has emerged as a promising model organism for affective or cognitive neuroscience research, and may be useful to study the interplay between memory and anxiety-related states. To assess the effects of acute psychological stress on spatial and cued memory, adult zebrafish were trained in an aquatic plus-maze for 14 days using food bait as a reward. Two ecologically relevant stressors (alarm pheromone or Indian leaf fish exposure) were applied to acutely stress zebrafish immediately prior to the final (testing) trial. Overall, acute single inescapable stress markedly impaired spatial and cued memory in zebrafish plus-maze test, reducing the number of correct arm entries and time spent in the target arm. This observation parallels rodent and clinical literature on memory-impairing effects of acute stress, strongly supporting the utility of zebrafish in neurobehavioral research. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. A Novel Zebrafish Model to Provide Mechanistic Insights into the Inflammatory Events in Carrageenan-Induced Abdominal Edema

    PubMed Central

    Huang, Shi-Ying; Feng, Chien-Wei; Hung, Han-Chun; Chakraborty, Chiranjib; Chen, Chun-Hong; Chen, Wu-Fu; Jean, Yen-Hsuan; Wang, Hui-Min David; Sung, Chun-Sung; Sun, Yu-Min; Wu, Chang-Yi; Liu, Wangta; Hsiao, Chung-Der; Wen, Zhi-Hong

    2014-01-01

    A suitable small animal model may help in the screening and evaluation of new drugs, especially those from natural products, which can be administered at lower dosages, fulfilling an urgent worldwide need. In this study, we explore whether zebrafish could be a model organism for carrageenan-induced abdominal edema. The research results showed that intraperitoneal (i.p.) administration of 1.5% λ-carrageenan in a volume of 20 µL significantly increased abdominal edema in adult zebrafish. Levels of the proinflammatory proteins tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) were increased in carrageenan-injected adult zebrafish during the development of abdominal edema. An associated enhancement was also observed in the leukocyte marker, myeloperoxidase (MPO). To support these results, we further observed that i.p. methylprednisolone (MP; 1 µg), a positive control, significantly inhibited carrageenan-induced inflammation 24 h after carrageenan administration. Furthermore, i.p. pretreatment with either an anti-TNF-α antibody (1∶5 dilution in a volume of 20 µL) or the iNOS-selective inhibitor aminoguanidine (AG; 1 µg) inhibited carrageenan-induced abdominal edema in adult zebrafish. This new animal model is uncomplicated, easy to develop, and involves a straightforward inducement of inflammatory edema for the evaluation of small volumes of drugs or test compounds. PMID:25141004

  12. The Zebrafish as a New Model for the In Vivo Study of Shigella flexneri Interaction with Phagocytes and Bacterial Autophagy

    PubMed Central

    Mostowy, Serge; Boucontet, Laurent; Mazon Moya, Maria J.; Sirianni, Andrea; Boudinot, Pierre; Hollinshead, Michael; Cossart, Pascale; Herbomel, Philippe; Levraud, Jean-Pierre; Colucci-Guyon, Emma

    2013-01-01

    Autophagy, an ancient and highly conserved intracellular degradation process, is viewed as a critical component of innate immunity because of its ability to deliver cytosolic bacteria to the lysosome. However, the role of bacterial autophagy in vivo remains poorly understood. The zebrafish (Danio rerio) has emerged as a vertebrate model for the study of infections because it is optically accessible at the larval stages when the innate immune system is already functional. Here, we have characterized the susceptibility of zebrafish larvae to Shigella flexneri, a paradigm for bacterial autophagy, and have used this model to study Shigella-phagocyte interactions in vivo. Depending on the dose, S. flexneri injected in zebrafish larvae were either cleared in a few days or resulted in a progressive and ultimately fatal infection. Using high resolution live imaging, we found that S. flexneri were rapidly engulfed by macrophages and neutrophils; moreover we discovered a scavenger role for neutrophils in eliminating infected dead macrophages and non-immune cell types that failed to control Shigella infection. We observed that intracellular S. flexneri could escape to the cytosol, induce septin caging and be targeted to autophagy in vivo. Depletion of p62 (sequestosome 1 or SQSTM1), an adaptor protein critical for bacterial autophagy in vitro, significantly increased bacterial burden and host susceptibility to infection. These results show the zebrafish larva as a new model for the study of S. flexneri interaction with phagocytes, and the manipulation of autophagy for anti-bacterial therapy in vivo. PMID:24039575

  13. p-Nitrophenol and glutathione response in medaka (Oryzias latipes) exposed to MX, a drinking water carcinogen.

    PubMed

    Geter, David R; Fournie, John W; Brouwer, Marius H; DeAngelo, Anthony B; Hawkins, William E

    2003-03-01

    When chlorine is introduced into public drinking water for disinfection, it can react with organic compounds in surface waters to form toxic by-products such as 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX). We investigated the effect of exposure to MX on cytochrome P450 2E1 (CYP2E1)-like activity and total glutathione (GSH) in the liver of the small fish model, medaka (Oryzias latipes). The multi-site carcinogen methylazoxymethanol acetate (MAMAc) was the positive control compound. Both medaka liver microsome preparations and S-9 fractions catalyzed the hydroxylation of p-nitrophenol (PNP), suggesting CYP2E1-like activity in the medaka. Male medaka exposed for 96 h to the CYP2E1 inducers ethanol and acetone under fasted conditions showed significant increases in PNP-hydroxylation activity. Furthermore, total reduced hepatic GSH was reduced in fish fasted for 96 h, indicating that normal feeding is a factor in maintaining xenobiotic defenses. Exposure to MX and MAMAc induced significant increases in hepatic CYP2E1-like activity, however MX exposure did not alter hepatic GSH levels. These data strengthen the role of the medaka as a suitable species for examining cytochrome P450 and GSH detoxification processes and the role these systems play in chemical carcinogenesis.

  14. A zebrafish larval model reveals early tissue-specific innate immune responses to Mucor circinelloides.

    PubMed

    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. ptk7 mutant zebrafish models of congenital and idiopathic scoliosis implicate dysregulated Wnt signalling in disease

    PubMed Central

    Hayes, Madeline; Gao, Xiaochong; Yu, Lisa X; Paria, Nandina; Henkelman, R. Mark; Wise, Carol A.; Ciruna, Brian

    2014-01-01

    Scoliosis is a complex genetic disorder of the musculoskeletal system, characterized by three-dimensional rotation of the spine. Curvatures caused by malformed vertebrae (congenital scoliosis (CS)) are apparent at birth. Spinal curvatures with no underlying vertebral abnormality (idiopathic scoliosis (IS)) most commonly manifest during adolescence. The genetic and biological mechanisms responsible for IS remain poorly understood due largely to limited experimental models. Here we describe zygotic ptk7 (Zptk7) mutant zebrafish, deficient in a critical regulator of Wnt signalling, as the first genetically defined developmental model of IS. We identify a novel sequence variant within a single IS patient that disrupts PTK7 function, consistent with a role for dysregulated Wnt activity in disease pathogenesis. Furthermore, we demonstrate that embryonic loss-of-gene function in maternal-zygotic ptk7 mutants (MZptk7) leads to vertebral anomalies associated with CS. Our data suggest novel molecular origins of, and genetic links between, congenital and idiopathic forms of disease. PMID:25182715

  16. ptk7 mutant zebrafish models of congenital and idiopathic scoliosis implicate dysregulated Wnt signalling in disease.

    PubMed

    Hayes, Madeline; Gao, Xiaochong; Yu, Lisa X; Paria, Nandina; Henkelman, R Mark; Wise, Carol A; Ciruna, Brian

    2014-09-03

    Scoliosis is a complex genetic disorder of the musculoskeletal system, characterized by three-dimensional rotation of the spine. Curvatures caused by malformed vertebrae (congenital scoliosis (CS)) are apparent at birth. Spinal curvatures with no underlying vertebral abnormality (idiopathic scoliosis (IS)) most commonly manifest during adolescence. The genetic and biological mechanisms responsible for IS remain poorly understood due largely to limited experimental models. Here we describe zygotic ptk7 (Zptk7) mutant zebrafish, deficient in a critical regulator of Wnt signalling, as the first genetically defined developmental model of IS. We identify a novel sequence variant within a single IS patient that disrupts PTK7 function, consistent with a role for dysregulated Wnt activity in disease pathogenesis. Furthermore, we demonstrate that embryonic loss-of-gene function in maternal-zygotic ptk7 mutants (MZptk7) leads to vertebral anomalies associated with CS. Our data suggest novel molecular origins of, and genetic links between, congenital and idiopathic forms of disease.

  17. From Omics to Drug Metabolism and High Content Screen of Natural Product in Zebrafish: A New Model for Discovery of Neuroactive Compound

    PubMed Central

    Hung, Ming Wai; Zhang, Zai Jun; Li, Shang; Lei, Benson; Yuan, Shuai; Cui, Guo Zhen; Man Hoi, Pui; Chan, Kelvin; Lee, Simon Ming Yuen

    2012-01-01

    The zebrafish (Danio rerio) has recently become a common model in the fields of genetics, environmental science, toxicology, and especially drug screening. Zebrafish has emerged as a biomedically relevant model for in vivo high content drug screening and the simultaneous determination of multiple efficacy parameters, including behaviour, selectivity, and toxicity in the content of the whole organism. A zebrafish behavioural assay has been demonstrated as a novel, rapid, and high-throughput approach to the discovery of neuroactive, psychoactive, and memory-modulating compounds. Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs. Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches. Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed. PMID:22919414

  18. Intrinsic regulation of sinoatrial node function and the zebrafish as a model of stretch effects on pacemaking.

    PubMed

    MacDonald, Eilidh A; Stoyek, Matthew R; Rose, Robert A; Quinn, T Alexander

    2017-07-22

    Excitation of the heart occurs in a specialised region known as the sinoatrial node (SAN). Tight regulation of SAN function is essential for the maintenance of normal heart rhythm and the response to (patho-)physiological changes. The SAN is regulated by extrinsic (central nervous system) and intrinsic (neurons, peptides, mechanics) factors. The positive chronotropic response to stretch in particular is essential for beat-by-beat adaptation to changes in hemodynamic load. Yet, the mechanism of this stretch response is unknown, due in part to the lack of an appropriate experimental model for targeted investigations. We have been investigating the zebrafish as a model for the study of intrinsic regulation of SAN function. In this paper, we first briefly review current knowledge of the principal components of extrinsic and intrinsic SAN regulation, derived primarily from experiments in mammals, followed by a description of the zebrafish as a novel experimental model for studies of intrinsic SAN regulation. This mini-review is followed by an original investigation of the response of the zebrafish isolated SAN to controlled stretch. Stretch causes an immediate and continuous increase in beating rate in the zebrafish isolated SAN. This increase reaches a maximum part way through a period of sustained stretch, with the total change dependent on the magnitude and direction of stretch. This is comparable to what occurs in isolated SAN from most mammals (including human), suggesting that the zebrafish is a novel experimental model for the study of mechanisms involved in the intrinsic regulation of SAN function by mechanical effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Mutation of zebrafish dihydrolipoamide branched-chain transacylase E2 results in motor dysfunction and models maple syrup urine disease.

    PubMed

    Friedrich, Timo; Lambert, Aaron M; Masino, Mark A; Downes, Gerald B

    2012-03-01

    Analysis of zebrafish mutants that demonstrate abnormal locomotive behavior can elucidate the molecular requirements for neural network function and provide new models of human disease. Here, we show that zebrafish quetschkommode (que) mutant larvae exhibit a progressive locomotor defect that culminates in unusual nose-to-tail compressions and an inability to swim. Correspondingly, extracellular peripheral nerve recordings show that que mutants demonstrate abnormal locomotor output to the axial muscles used for swimming. Using positional cloning and candidate gene analysis, we reveal that a point mutation disrupts the gene encoding dihydrolipoamide branched-chain transacylase E2 (Dbt), a component of a mitochondrial enzyme complex, to generate the que phenotype. In humans, mutation of the DBT gene causes maple syrup urine disease (MSUD), a disorder of branched-chain amino acid metabolism that can result in mental retardation, severe dystonia, profound neurological damage and death. que mutants harbor abnormal amino acid levels, similar to MSUD patients and consistent with an error in branched-chain amino acid metabolism. que mutants also contain markedly reduced levels of the neurotransmitter glutamate within the brain and spinal cord, which probably contributes to their abnormal spinal cord locomotor output and aberrant motility behavior, a trait that probably represents severe dystonia in larval zebrafish. Taken together, these data illustrate how defects in branched-chain amino acid metabolism can disrupt nervous system development and/or function, and establish zebrafish que mutants as a model to better understand MSUD.

  20. Modeling interactions and toxicity of Cu-Zn mixtures to zebrafish larvae.

    PubMed

    Gao, Yongfei; Feng, Jianfeng; Wang, Cancan; Zhu, Lin

    2017-04-01

    Quantitative predictions of metal-metal interactions and toxicity in aquatic organisms meet a unique challenge. Accumulation and toxicity of Cu and Zn mixtures in zebrafish larvae has been quantified in binary metal system with variable combinatorial concentrations in order to understand the interactions between essential trace metals and assess availability of the toxicokinetic-toxicodynamic (TK-TD) model which simulated the uptake of metals over time as well as metal toxicity after 24h of exposure. Competitive uptake experiments showed a straightforward antagonistic competition, as would be predicted by Michaelis-Menten competitive equilibrium model. Zn uptake decreased significantly in the presence of Cu(2+) concentrations higher than 10(-6)M. Cu(2+) was shown to compete strongly with Zn for uptake, having a higher affinity constant to biotic ligand (BL) sites (KCuBL=10(5.42)M(-1)) than Zn (KZnBL=10(4.13)M(-1)). TK-TD model considering potential metal-metal antagonism interactions showed good predictive power in predicting accumulation and toxicity of Cu-Zn mixtures