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Sample records for rerio oryzias latipes

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

    PubMed

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

    2015-05-01

    Oryzias latipes, Danio rerio, Cyprinus carpio, and Zacco platypus are useful indicator species for CYP1A biomarker studies; however, comparative studies have not been performed. To compare susceptibility, dose- and time-dependent CYP1A induction at the mRNA and protein levels in response to benzo(a)pyrene (BaP) exposure was analyzed. At the mRNA level, a statistically significant difference was found among the four species; however, such was not observed at the protein level. C. carpio showed the highest CYP1A induction level and the steepest slope in the dose-response curve. To assess susceptibility, the difference in CYP1A mRNA induction among species must be considered, and C. carpio was the most sensitive species of the four evaluated in terms of CYP1A expression. PMID:25863331

  2. XENOBIOTIC INDUCED ORGAN-SPECIFIC GENE EXPRESSION AND MACRO/MICROARRAY DEVELOPMENT IN MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    As part of an ongoing effort to understand and address the short and long-term consequences of increasing levels of environmental contaminants, we used suppressive subtractive hydridization (SSH) to develop gene expression profiles from Japanese medaka (Oryzias latipes) exposed ...

  3. Chlorpyrifos-induced biomarkers in Japanese medaka (Oryzias latipes).

    PubMed

    Jeon, Hwang-Ju; Lee, Yong-Ho; Mo, Hyoung-ho; Kim, Myoung-Jin; Al-Wabel, Mohammad I; Kim, Yongeun; Cho, Kijong; Kim, Tae-Wan; Ok, Yong Sik; Lee, Sung-Eun

    2016-01-01

    Chlorpyrifos (CHL) is an organophosphate compound that is widely used as an insecticide. Due to its repeated use and high environmental residual property, CHL is frequently passed into aquatic environments by runoff. Consequently, there may be an adverse effect on aquatic vertebrate animals, including fish. Therefore, in this study, we assessed how CHL affected Japanese medaka (Oryzias latipes). The acute toxicity of CHL in adult fish after 96 h of exposure was determined to be 212.50, 266.79, and 412.28 μg L(-1) (LC25, LC50, and LC95, respectively). Acetylcholinesterase (AChE), glutathione S-transferase (GST), and carboxylesterase (CE) activities were obtained from the livers of dead or surviving fish, and the results showed 4.8-fold lower, 4.5-fold higher, and 18.6-fold lower activities for the AChE, GST, and CE, respectively, for 64-h exposure at a concentration of 400 μg L(-1) of CHL. In the embryo toxicity test, curved spines were observed in embryos that were exposed to CHL for 48 h in a concentration-dependent manner. With identification of biomarkers for CHL in the fish, two protein peaks, 5550.86 and 5639.79 m/z, were found to be upregulated. These two proteins can be used as protein biomarkers for CHL contamination in aquatic systems. A phosphatidyl choline with an m/z ratio of 556.32 dramatically decreased after CHL exposure in the fish; thus, it may be considered as a lipid biomarker for CHL. It is assumed as the first report to identify a phospholipid biomarker using a lipidomics approach in fish toxicology. Taken together, these results demonstrated the adverse effects of CHL on Japanese medaka and reveal several candidate biomarkers that can be used as diagnostic tools for determining CHL.

  4. Functional characterization of visual opsin repertoire in Medaka (Oryzias latipes).

    PubMed

    Matsumoto, Yoshifumi; Fukamachi, Shoji; Mitani, Hiroshi; Kawamura, Shoji

    2006-04-26

    A variety of visual pigment repertoires present in fish species is believed due to the great variation under the water of light environment. A complete set of visual opsin genes has been isolated and characterized for absorption spectra and expression in the retina only in zebrafish. Medaka (Oryzias latipes) is a fish species phylogenetically distant from zebrafish and has served as an important vertebrate model system in molecular and developmental genetics. We previously isolated a medaka rod opsin gene (RH1). In the present study we isolated all the cone opsin genes of medaka by genome screening of a lambda-phage and bacterial artificial chromosome (BAC) libraries. The medaka genome contains two red, LWS-A and LWS-B, three green, RH2-A, RH2-B and RH2-C, and two blue, SWS2-A and SWS2-B, subtype opsin genes as well as a single-copy of the ultraviolet, SWS1, opsin gene. Previously only one gene was believed present for each opsin type as reported in a cDNA-based study. These subtype opsin genes are closely linked and must be the products of local gene duplications but not of a genome-wide duplication. Peak absorption spectra (lambda(max)) of the reconstituted photopigments with 11-cis retinal varied greatly among the three green opsins, 452 nm for RH2-A, 516 nm for RH2-B and 492 nm for RH2-C, and between the two blue opsins, 439 nm for SWS2-A and 405 nm for SWS2-B. Zebrafish also has multiple opsin subtypes, but phylogenetic analysis revealed that medaka and zebrafish gained the subtype opsins independently. The lambda and BAC DNA clones isolated in this study could be useful for investigating the regulatory mechanisms and evolutionary diversity of fish opsin genes.

  5. PROLIFERATIVE LESIONS IN SWIMBLADDER OF JAPANESE MEDAKA ORYZIAS LATIPES AND GUPPY POECILIA RETICULATA

    EPA Science Inventory

    Thirteen cases of proliferative lesions of the swimbladder were encountered in Japanese medaka Oryzias latipes and guppy Poecilia reticulata from about 10,000 medaka and 5,000 guppies used in carcinogenicity tests and histologically examined. Two of the four cases from medaka and...

  6. NOVEL ASSAY TO ASSESS CYP-2E1-LIKE ACTIVITY IN THE JAPANESE MEDAKA (ORYZIAS LATIPES).

    EPA Science Inventory

    Liver microsomes and S-9 fraction of Japanese medaka (Oryzias latipes) metabolized the CYP2E1 specific substrate, p-nitrophenol (PNP), to a single hydroxylated product, 4-nitrocatechol. The use of liver S-9 fraction proved to be a viable alternative to liver microsomes and allowe...

  7. GENDER-SPECIFIC GROWTH AND HEPATIC NEOPLASIA IN MEDAKA (ORYZIAS LATIPES). (R825433)

    EPA Science Inventory

    Brief exposure of hatchling medaka (Oryzias latipes), to diethylnitrosamine (DEN), resulted in hepatic tumor formation in female medaka at an incidence of 2–3-fold higher than that of their male cohorts. Spontaneous liver tumor incidence was reported in unexposed...

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

    EPA Science Inventory

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

  9. 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...

  10. 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).

  11. Expression of plzfa in embryo and adult of medaka Oryzias latipes.

    PubMed

    Zhao, H B; Zhang, X Y; Feng, G Q; Guo, M M; Chang, P; Qi, C; Zhong, X P; Zhou, Q C; Wang, J L

    2015-08-01

    In this study, a homologous gene named plzfa was identified and characterized in medaka Oryzias latipes. Oryzias latipes plzfa was detected in all the tissues including brain, gill, muscle, liver, intestine, kidney, spleen, testis and ovary using reverse transcriptase (RT)-PCR. plzfa was detected in the oocytes of the ovary and in the spermatogonia and somitic cells of the testis by in situ hybridization. plzfa had a maternal origin with continuous and dynamic expression during embryonic development. plzfa was observed in the brain, neural rod and sensor organs including the eyes, ears and nose during embryogenesis. plzfa was also detected in the neural crest, somite, pectoral fin, intestine and skin. These results indicate that plzfa is a pleiotropic gene that may play major roles in various tissues. PMID:26077174

  12. Intrinsically disordered and pliable Starmaker-like protein from medaka (Oryzias latipes) controls the formation of calcium carbonate crystals.

    PubMed

    Różycka, Mirosława; Wojtas, Magdalena; Jakób, Michał; Stigloher, Christian; Grzeszkowiak, Mikołaj; Mazur, Maciej; Ożyhar, Andrzej

    2014-01-01

    Fish otoliths, biominerals composed of calcium carbonate with a small amount of organic matrix, are involved in the functioning of the inner ear. Starmaker (Stm) from zebrafish (Danio rerio) was the first protein found to be capable of controlling the formation of otoliths. Recently, a gene was identified encoding the Starmaker-like (Stm-l) protein from medaka (Oryzias latipes), a putative homologue of Stm and human dentine sialophosphoprotein. Although there is no sequence similarity between Stm-l and Stm, Stm-l was suggested to be involved in the biomineralization of otoliths, as had been observed for Stm even before. The molecular properties and functioning of Stm-l as a putative regulatory protein in otolith formation have not been characterized yet. A comprehensive biochemical and biophysical analysis of recombinant Stm-l, along with in silico examinations, indicated that Stm-l exhibits properties of a coil-like intrinsically disordered protein. Stm-l possesses an elongated and pliable structure that is able to adopt a more ordered and rigid conformation under the influence of different factors. An in vitro assay of the biomineralization activity of Stm-l indicated that Stm-l affected the size, shape and number of calcium carbonate crystals. The functional significance of intrinsically disordered properties of Stm-l and the possible role of this protein in controlling the formation of calcium carbonate crystals is discussed.

  13. Intrinsically Disordered and Pliable Starmaker-Like Protein from Medaka (Oryzias latipes) Controls the Formation of Calcium Carbonate Crystals

    PubMed Central

    Różycka, Mirosława; Wojtas, Magdalena; Jakób, Michał; Stigloher, Christian; Grzeszkowiak, Mikołaj; Mazur, Maciej; Ożyhar, Andrzej

    2014-01-01

    Fish otoliths, biominerals composed of calcium carbonate with a small amount of organic matrix, are involved in the functioning of the inner ear. Starmaker (Stm) from zebrafish (Danio rerio) was the first protein found to be capable of controlling the formation of otoliths. Recently, a gene was identified encoding the Starmaker-like (Stm-l) protein from medaka (Oryzias latipes), a putative homologue of Stm and human dentine sialophosphoprotein. Although there is no sequence similarity between Stm-l and Stm, Stm-l was suggested to be involved in the biomineralization of otoliths, as had been observed for Stm even before. The molecular properties and functioning of Stm-l as a putative regulatory protein in otolith formation have not been characterized yet. A comprehensive biochemical and biophysical analysis of recombinant Stm-l, along with in silico examinations, indicated that Stm-l exhibits properties of a coil-like intrinsically disordered protein. Stm-l possesses an elongated and pliable structure that is able to adopt a more ordered and rigid conformation under the influence of different factors. An in vitro assay of the biomineralization activity of Stm-l indicated that Stm-l affected the size, shape and number of calcium carbonate crystals. The functional significance of intrinsically disordered properties of Stm-l and the possible role of this protein in controlling the formation of calcium carbonate crystals is discussed. PMID:25490041

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. The genomic and genetic toolbox of the teleost medaka (Oryzias latipes).

    PubMed

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

    2015-04-01

    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.

  16. 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

  17. Circus movement in dissociated embryonic cells of a teleost, Oryzias latipes.

    PubMed

    Fujinami, N; Kageyama, T

    1975-10-01

    The dissociated early embryonic cells of the fresh water fish, Oryzias latipes, protrude hyaline lobopodia, which tend to rotate around the cell circumference in a propagating wave. Cells from late blastula or gastrula continuously show this "circus movement", while most cells up to early blastula are rounded. The linear velocity of the lobopodium was estimated by means of time-lapse cinemicrography. The velocity increases slightly as cell diameter increases. The effects of pH, temperature and osmotic pressure of the immersion media on the movement were also quantitatively investigated. Cells become rounded and do not form lobopodial blebs when immersed in media below pH 5. The velocity is reduced by decreasing temperature, but the movement continues even at 5 degrees C. Cells placed in hypertonic salt solutions become crenated and do not continuously demonstrate the circus movement.

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

    PubMed

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

    2008-01-01

    Cartap and cypermethrin, which are among the most widely used pesticides in many countries, are considered safe because of their low mammalian toxicity and their low persistence in the environment. However, recent findings of endocrine-disrupting effects and developmental neurotoxicity have raised concerns about the potential ecological impacts of these pesticides. We evaluated the aquatic toxicity of cartap [S,S'-(2-dimethylaminotrimethylene) bis(thiocarbamate), unspecified hydrochloride] and cypermethrin [(RS)-alpha-cyano-3-phenoxybenzyl-(1RS,3RS,1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate], both individually and combined, on different life stages of the freshwater cladoceran Daphnia magna and a freshwater teleost, Japanese medaka (Oryzias latipes). The 96-hr Daphnia median effective concentrations (EC50s) for cartap and cypermethrin were 91.0 microg/L and 0.00061 microg/L, respectively. Rapid recovery of Daphnia was observed after short-term pulsed exposure to cartap and cypermethrin; there were no adverse effects on reproduction or survival 20 d after a 24 hr exposure to cartap up to 1240 microg/L and cypermethrin up to 1.9 microg/L. Chronic continuous exposure (for 21 d) of 7-d-old Daphnia to cypermethrin significantly reduced the intrinsic population growth rate in a concentration-dependent manner. However, because the intrinsic population growth rates were all above zero, populations did not decrease even at the highest experimental concentration of 200 ng/L. Exposure of Daphnia neonates (< 24 hr old) to cypermethrin for 21 d caused significant, sub-lethal reproduction-related problems, such as increased time to first brood, reduced brood size, and reduced total brood number, at 0.0002, 0.002, and 0.2 ng/L cypermethrin, but the intrinsic population growth rate was not significantly affected. Oryzias latipes was relatively more resistant to both pesticides. In particular, embryos appeared to be more resistant than juveniles or adults

  19. Effects of the isoflavones genistein and equol on the gonadal development of Japanese medaka Oryzias latipes.

    PubMed Central

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

    2003-01-01

    The estrogenic isoflavone compound genistein recently has been found in the effluents of sewage treatment plants and pulp mills, and the related compound equol has been detected in the runoff from agricultural fields treated with hog manure. Waterborne exposures of Japanese medaka (Oryzias latipes) to equol from soon after hatch to approximately 100 days posthatch induced gonadal intersex (i.e., testis-ova) in males at incidences of 10 and 87% in equol treatments of 0.4 and 0.8 micro g/L, respectively. Exposure to the highest test concentration of genistein, 1,000 micro g/L, also caused a low incidence (i.e., 12%) of gonadal intersex in male medaka. The ovaries of female medaka from both equol and genistein treatments showed delayed oocyte maturation, atretic oocytes, an enlarged ovarian lumen, proliferation of somatic stromal tissue, and primordial germ cells; responses were concentration dependent. Alterations to externally visible secondary sex characteristics occurred in medaka exposed to both equol and genistein. In treatments with 1,000 micro g/L genistein, 72% of male medaka (as identified by the gonadal phenotype) showed feminized secondary sex characteristics. Gonadal intersex and alterations to secondary sex characteristics have been noted in several fish populations around the world. This laboratory study indicates that isoflavone compounds should be considered candidate estrogenic compounds that may be involved in the alteration of sexual development in feral fish populations. PMID:12842767

  20. 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.

  1. Disruption of dmc1 Produces Abnormal Sperm in Medaka (Oryzias latipes)

    PubMed Central

    Chen, Ji; Cui, Xiaojuan; Jia, Shaoting; Luo, Daji; Cao, Mengxi; Zhang, Yunsheng; Hu, Hongling; Huang, Kaiyao; Zhu, Zuoyan; Hu, Wei

    2016-01-01

    DMC1 is a recombinase that is essential for meiotic synapsis. Experiments in extensive species of eukaryotes have indicated the independent role of DMC1 in repairing double strand breaks (DSBs) produced during meiosis I. Mutation of dmc1 in mice and human often leads to obstacles in spermatogenesis and male sterility. Here, we report on the disruption of dmc1 in male medaka (Oryzias latipes). Synapsis was disturbed in the mutant medaka testis nuclei, as observed in mice and other organisms. Unexpectedly, the mutant medaka could produce a few sperm and, although most of these had multiple tail or multiple head malformations, some of them could swim, and few of them even had insemination ability. Our transcriptome analysis showed that there was not a remarkable change in the expression of most of the genes involved in the pathways associated with the meiotic DNA repair and flagella assembly. Our results provided an indication of the accessory mechanisms that might be involved in the repair of DSBs during meiosis. In a species besides humans, we provided evidence that disorders in meiosis recombination might lead to the malformation of sperm. PMID:27480068

  2. Hertwig effect caused by UV-irradiation of sperm of Oryzias latipes (teleost) and its photoreactivation.

    PubMed

    Ijiri, K; Egami, N

    1980-02-01

    When sperm of the fish Oryzias latipes were irradiated with ultraviolet light and allowed to fertilize normal eggs, the so-called "Hertwig effect" was observed, with a dose-dependent decrease in survival rate at low doses (0-27 J . m-2) but a better survival rate at higher dose ranges. Illumination with visible light after fertilization (10-70 min after insemination) showed the existence of photoreactivation (PR), demonstrating that pyrimidine dimers are a lesion in sperm DNA that is mainly responsible for the UV-caused Hertwig effect. Genetic analysis, in which sperm from a wild-type of this fish was used, showed that, after UV-irradiation at the high dose range, male nuclei did not participate in embryonic development (a gynogenetic haploid condition). Embryos having only a maternal set of chromosomes could develop no further than stage 27. Only the visible light during the early part (until around 20-30 min after insemination, at 25 degrees C) of the single-cell stage was effective for PR; illumination thereafter was not. PMID:7360147

  3. The effects of methyltestosterone on the sexual development and reproduction of adult medaka (Oryzias latipes).

    PubMed

    Kang, Ik Joon; Yokota, Hirofumi; Oshima, Yuji; Tsuruda, Yukinari; Shimasaki, Yohei; Honjo, Tsuneo

    2008-04-01

    We examined the effects of methyltestosterone (MT) on the reproduction of medaka (Oryzias latipes). Six mating pairs of medaka were exposed for 3 weeks to MT at the measured concentrations of 22.5, 46.8, 88.1, 188, and 380 ng/L. The fecundity and fertility of paired medaka were significantly decreased in the 46.8, 88.1, 188, and 380 ng/L MT groups compared with those of controls. The gonadosomatic indices of female fish exposed to >or=46.8 ng/L were increased significantly. Gonadal histology showed degeneration of oocytes in the ovaries of fish in all MT treatment groups. Hepatic vitellogenin concentrations were significantly decreased in female fish treated with MT at 188 and 380 ng/L, and the hatchability and survival rate of the offspring were decreased in all MT treatment groups. These results clearly demonstrate that MT at >or=46.8 ng/L inhibited gonadal development and adversely affected the reproduction of medaka.

  4. The toxicity of titanium dioxide nanopowder to early life stages of the Japanese medaka (Oryzias latipes).

    PubMed

    Paterson, Gordon; Ataria, Jamie M; Hoque, M Ehsanul; Burns, Darcy C; Metcalfe, Chris D

    2011-02-01

    In this study, fertilized Japanese medaka (Oryzias latipes) embryos were exposed from fertilization to 5 d post-hatch using static non-renewal assays to aqueous suspensions of titanium dioxide nanoparticles (nTiO₂) ranging in nominal concentrations between 0 and 14 μg mL⁻¹. The average size of the nTiO₂ in the stock solution before addition to the test treatments was 87 nm (±14 nm). TiO₂ materials accumulated in a concentration dependent manner on the chorionic filaments of developing medaka embryos with evidence of pericardial edema occurring during embryo development. However, no significant (p > 0.05) increases in mortality relative to control treatments were observed for the nTiO₂ exposed embryos. A concentration dependent increase in cumulative percent hatch was observed at 11 d, indicating that exposure to increasing concentrations of nTiO₂ resulted in the premature hatch of medaka embryos. Post-hatch, a significant proportion of sac fry from the nTiO₂ exposure groups exhibited moribund swimming behavior and these individuals also experienced greater mortality at 15 d post-hatch. Combined, these results demonstrate that exposure to nTiO₂ can impact the development of early life stages of fish. PMID:21074241

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

    PubMed

    Dong, Wu; Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity. PMID:27635309

  6. Avoidance by olfaction in a fish, medaka (Oryzias latipes), to aquatic contaminants.

    PubMed

    Hidaka, H; Tatsukawa, R

    1989-01-01

    Behavioral tests using a fish, medaka (Oryzias latipes), from which the olfactory organs were resected confirmed that fish avoid aquatic contaminants such as surfactants and pesticides mainly by olfaction. Control medaka (non-resected) exhibited significant avoidance to 10, 20 and 30 microg liter(-1) of LAS (sodium linear laurylbenzene sulfonate), 90 and 100 microg liter(-1) of fenitrothion (dimethyl 4-nitro-m-toryl phosphorothionate), and 500 microg liter(-1) of POE-ether (polyoxyethylene lauryl ether). By contrast, medaka with bilateral nose resections (BNRM) exhibited no avoidance to 10-50 microg liter(-1) of LAS, 90 and 100 microg liter(-1) of fenitrothion, and 500 microg liter(-1) of POE-ether. Although medaka with unilateral nose resection (UNRM) avoided some concentrations of these toxicants, the UNRM exhibited no avoidance to 10 and 40 microg liter(-1) of LAS and 90 microg liter(-1) of fenitrothion. That is, the avoidance response of the UNRM was less distinct than that of the controls. This difference may have been caused by the deterioration of detecting ability and the paralyzation or adaptation of olfaction.

  7. Alterations in social behavior of Japanese medaka (Oryzias latipes) in response to sublethal chlorpyrifos exposure.

    PubMed

    Khalil, Fatma; Kang, Ik Joon; Undap, Suzanne; Tasmin, Rumana; Qiu, Xuchun; Shimasaki, Yohei; Oshima, Yuji

    2013-06-01

    The behavioral and biochemical responses of Japanese medaka (Oryzias latipes) to acute and subacute (sublethal) levels of chlorpyrifos were studied. In the acute exposure test, medaka were exposed to 0.018, 0.055, 0.166, or 0.500 mg L(-1) chlorpyrifos for 4 d. As a result, fish showed hypoactivity compared to the control (at 0.018, 0.055, and 0.166 mg L(-1), swimming speeds were 55.6%, 39.0%, and 27.3% those of the control), Brain acetylcholinesterase activity and swimming speed were significantly correlated. In the subacute toxicity test, medaka were exposed to 0.012 mg L(-1) chlorpyrifos (10% of LC(50)) for 8 d. On day 4, there were no significant differences in behavioral and biochemical endpoints in exposed fish as compared to the control. On day 8, exposed fish became hyperactive, and the swimming speed of the social group increased to 2 times that of the control, whereas acetylcholinesterase activity was decreased to 68% that of the control. In addition, fish exhibited significant alterations in social behavior (schooling duration increased to 2.6 times and solitary duration decreased to 28% that of the control). Our findings clearly demonstrate a subacute effect of chlorpyrifos on the social behavior of medaka, which may pose a risk at population level because of the disturbance of social behavior. In addition, the recorded behavioral alterations may provide a useful tool for assessing the toxicity of organophosphorous pesticides to aquatic organisms.

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

    USGS Publications Warehouse

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

    2000-01-01

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

  9. Disruption of dmc1 Produces Abnormal Sperm in Medaka (Oryzias latipes).

    PubMed

    Chen, Ji; Cui, Xiaojuan; Jia, Shaoting; Luo, Daji; Cao, Mengxi; Zhang, Yunsheng; Hu, Hongling; Huang, Kaiyao; Zhu, Zuoyan; Hu, Wei

    2016-01-01

    DMC1 is a recombinase that is essential for meiotic synapsis. Experiments in extensive species of eukaryotes have indicated the independent role of DMC1 in repairing double strand breaks (DSBs) produced during meiosis I. Mutation of dmc1 in mice and human often leads to obstacles in spermatogenesis and male sterility. Here, we report on the disruption of dmc1 in male medaka (Oryzias latipes). Synapsis was disturbed in the mutant medaka testis nuclei, as observed in mice and other organisms. Unexpectedly, the mutant medaka could produce a few sperm and, although most of these had multiple tail or multiple head malformations, some of them could swim, and few of them even had insemination ability. Our transcriptome analysis showed that there was not a remarkable change in the expression of most of the genes involved in the pathways associated with the meiotic DNA repair and flagella assembly. Our results provided an indication of the accessory mechanisms that might be involved in the repair of DSBs during meiosis. In a species besides humans, we provided evidence that disorders in meiosis recombination might lead to the malformation of sperm. PMID:27480068

  10. Bioaccumulation, subcellular distribution, and acute effects of chromium in Japanese medaka (Oryzias latipes).

    PubMed

    Li, Lixia; Chen, Hongxing; Bi, Ran; Xie, Lingtian

    2015-11-01

    Chromium (Cr) is an essential element but is toxic to aquatic organisms at elevated concentrations. In the present study, adult Japanese medaka (Oryzias latipes) were exposed to a sublethal hexavalent chromium (Cr(VI)) concentration via dissolved and dietary exposures for 6 d. Various measurements of Cr were made: bioaccumulation in different tissues, subcellular distribution in the liver, effects on antioxidants and acetylcholinesterase (AChE), and Cr-induced lipid peroxidation. The results showed that bioaccumulation increased dramatically in all tested tissues from dissolved exposure but only significantly in the intestine from dietary treatment, implying that dissolved exposure may be predominant for Cr accumulation in medaka. Subcellular distribution revealed that Cr accumulated in the liver was mainly (46%) associated with the heat-stable protein fraction. Among the antioxidants examined, catalase (CAT) responded to dissolved Cr exposure in most tissues whereas superoxide dismutase (SOD) was less responsive. Malondialdehyde concentrations were significantly elevated in most tissues examined in the dissolved Cr-exposed fish, but were only elevated in the liver and intestine in the dietary Cr-exposed fish. The AChE activity in the brain was stimulated by 49% in the dissolved Cr-exposed fish. Reductions in condition factor and gonadosomatic index were also observed. These data help in an understanding of Cr tissue distribution and the acute effects of Cr in Japanese medaka.

  11. Natural allelic variations of xenobiotic-metabolizing enzymes affect sexual dimorphism in Oryzias latipes

    PubMed Central

    Katsumura, Takafumi; Oda, Shoji; Nakagome, Shigeki; Hanihara, Tsunehiko; Kataoka, Hiroshi; Mitani, Hiroshi; Kawamura, Shoji; Oota, Hiroki

    2014-01-01

    Sexual dimorphisms, which are phenotypic differences between males and females, are driven by sexual selection. Interestingly, sexually selected traits show geographical variations within species despite strong directional selective pressures. This paradox has eluded many evolutionary biologists for some time, and several models have been proposed (e.g. ‘indicator model’ and ‘trade-off model’). However, disentangling which of these theories explains empirical patterns remains difficult, because genetic polymorphisms that cause variation in sexual differences are still unknown. In this study, we show that polymorphisms in cytochrome P450 (CYP) 1B1, which encodes a xenobiotic-metabolizing enzyme, are associated with geographical differences in sexual dimorphism in the anal fin morphology of medaka fish (Oryzias latipes). Biochemical assays and genetic cross experiments show that high- and low-activity CYP1B1 alleles enhanced and declined sex differences in anal fin shapes, respectively. Behavioural and phylogenetic analyses suggest maintenance of the high-activity allele by sexual selection, whereas the low-activity allele possibly has experienced positive selection due to by-product effects of CYP1B1 in inferred ancestral populations. The present data can elucidate evolutionary mechanisms behind genetic variations in sexual dimorphism and indicate trade-off interactions between two distinct mechanisms acting on the two alleles with pleiotropic effects of xenobiotic-metabolizing enzymes. PMID:25377463

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

    PubMed Central

    Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E.

    2016-01-01

    This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001–10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6–7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity. PMID:27635309

  13. Trenbolone acetate metabolites promote ovarian growth and development in adult Japanese medaka (Oryzias latipes).

    PubMed

    Forsgren, Kristy L; Qu, Shen; Lavado, Ramon; Cwiertny, David; Schlenk, Daniel

    2014-06-01

    Trenbolone acetate, a synthetic androgen, has been used as a growth promoter in beef cattle in the US since 1987. While several teleost studies have investigated the masculinization effects of the metabolite 17β-trenbolone, few have focused on the reproductive impacts of all three trenbolone acetate (TBA) metabolites including trendione. Adult female medaka (Oryzias latipes) were exposed to TBA metabolites (10, 100, and 1000ng/L) for 14days (n=3). Histological examination revealed that TBA metabolites (1000ng/L) significantly reduced the percentage of primary ovarian follicles and increased the percentage of vitellogenic follicles compared to control fish. 17α-Trenbolone significantly increased whereas trendione reduced whole body levels of estradiol-17β. Testosterone was significantly reduced by trendione treatment and only the highest dose of 17β-trenbolone and lowest dose of trendione altered 11-ketotestosterone. Additionally, TBA metabolites may be further broken down and/or metabolized or converted by the animal influencing both sex steroid levels and ovarian development. PMID:24780119

  14. Histopathology of Japanese medaka (Oryzias latipes) chronically exposed to a complex environmental mixture.

    PubMed

    Toussaint, M W; Wolfe, M J; Burton, D T; Hoffmann, F J; Shedd, T R; Gardner, H S

    1999-01-01

    Japanese medaka (Oryzias latipes) were used to evaluate the carcinogenicity of a complex groundwater that contained 5 U.S. Environmental Protection Agency priority pollutant heavy metals and 13 chlorinated aliphatic hydrocarbons. A test protocol that used 10 mg/L diethylnitrosamine (DEN) prior to groundwater exposure was designed to assess both initiation and promotion. The fish were exposed continuously for 9 mo with 0, 1, 5, or 25% groundwater, by volume, with either West Branch of Canal Creek water (Aberdeen Proving Ground-Edgewood Area, Aberdeen Proving Ground, MD) or dechlorinated tap water as the diluent, while concurrent controls were run in the laboratory. Incidental findings included various neoplasms in the nares, ovary, skeletal muscle, skin, swim bladder, testis, thymus, and thyroid. Factors evaluated during statistical analyses of fish neoplasm prevalence included diluent type, groundwater percentage, fish gender, and DEN initiation. Liver neoplasm prevalence was higher in DEN-initiated fish and was frequently higher in males. Concentrations of up to 25% groundwater, by volume, showed no evidence of being a complete carcinogen and showed no consistent, conclusive evidence of being a promoter.

  15. 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.

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

    PubMed Central

    Liu, Jie; Wei, Lixin; Jingfeng, Yang; Chernick, Melissa; Hinton, David E.

    2016-01-01

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

  17. Genotoxicity of oxy-PAHs to Japanese medaka (Oryzias latipes) embryos assessed using the comet assay.

    PubMed

    Dasgupta, Subham; Cao, Austin; Mauer, Brittany; Yan, Beizhan; Uno, Seiichi; McElroy, Anne

    2014-12-01

    Polycyclic aromatic hydrocarbons (PAHs) have long been recognized as important environmental toxicants. Despite a plethora of information on the fate and effects of parent PAHs, relatively little is known about the environmental fate and toxicity of ketone- and quinone-substituted PAH oxidation products (termed oxy-PAHs), particularly in the aquatic environment. This study begins to fill that gap using embryos of the Japanese medaka (Oryzias latipes) as a model species. The genotoxic potential of two environmentally relevant oxy-PAHs, acenaphthenequinone and 7,12-benz[a]anthracenquinone, was assessed using the comet assay. We found that both oxy-PAHs could cause significant increases in DNA damage after only 48 h of exposure at the lowest concentrations tested (5 μg/L). Comparisons of the genotoxic potential between these oxy-PAHs and their corresponding parent PAHs (acenaphthene and benz[a]anthracene) and a well-known mutagenic PAH, benzo[a]pyrene, indicated similar potencies among all five of these compounds, particularly after longer (7 day) exposures. This study demonstrates the mutagenic potential of oxy-PAHs to an in vivo fish embryo model and points out the need for further study of their environmental occurrence and biologic effects.

  18. 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. PMID:26821288

  19. Natural allelic variations of xenobiotic-metabolizing enzymes affect sexual dimorphism in Oryzias latipes.

    PubMed

    Katsumura, Takafumi; Oda, Shoji; Nakagome, Shigeki; Hanihara, Tsunehiko; Kataoka, Hiroshi; Mitani, Hiroshi; Kawamura, Shoji; Oota, Hiroki

    2014-12-22

    Sexual dimorphisms, which are phenotypic differences between males and females, are driven by sexual selection. Interestingly, sexually selected traits show geographical variations within species despite strong directional selective pressures. This paradox has eluded many evolutionary biologists for some time, and several models have been proposed (e.g. 'indicator model' and 'trade-off model'). However, disentangling which of these theories explains empirical patterns remains difficult, because genetic polymorphisms that cause variation in sexual differences are still unknown. In this study, we show that polymorphisms in cytochrome P450 (CYP) 1B1, which encodes a xenobiotic-metabolizing enzyme, are associated with geographical differences in sexual dimorphism in the anal fin morphology of medaka fish (Oryzias latipes). Biochemical assays and genetic cross experiments show that high- and low-activity CYP1B1 alleles enhanced and declined sex differences in anal fin shapes, respectively. Behavioural and phylogenetic analyses suggest maintenance of the high-activity allele by sexual selection, whereas the low-activity allele possibly has experienced positive selection due to by-product effects of CYP1B1 in inferred ancestral populations. The present data can elucidate evolutionary mechanisms behind genetic variations in sexual dimorphism and indicate trade-off interactions between two distinct mechanisms acting on the two alleles with pleiotropic effects of xenobiotic-metabolizing enzymes.

  20. Tooth replacement and putative odontogenic stem cell niches in pharyngeal dentition of medaka (Oryzias latipes).

    PubMed

    Abduweli, Dawud; Baba, Otto; Tabata, Makoto J; Higuchi, Kazunori; Mitani, Hiroshi; Takano, Yoshiro

    2014-04-01

    The small-sized teleost fish medaka, Oryzias latipes, has as many as 1000 pharyngeal teeth undergoing continuous replacement. In this study, we sought to identify the tooth-forming units and determine its replacement cycles, and further localize odontogenic stem cell niches in the pharyngeal dentition of medaka to gain insights into the mechanisms whereby continuous tooth replacement is maintained. Three-dimensional reconstruction of pharyngeal epithelium and sequential fluorochrome labeling of pharyngeal bones and teeth indicated that the individual functional teeth and their successional teeth were organized in families, each comprising up to five generations of teeth and successional tooth germs, and that the replacement cycle of functional teeth was approximately 4 weeks. BrdU label/chase experiments confirmed the existence of clusters of label-retaining epithelial cells at the posterior end of each tooth family where the expression of pluripotency marker Sox2 was confirmed by in situ hybridization. Label-retaining cells were also identified in the mesoderm immediately adjacent to the posterior end of each tooth family. These data suggest the importance of existence of slow-cycling dental epithelial cells and Sox2 expressions at the posterior end of each tooth family to maintain continuous tooth formation and replacement in the pharyngeal dentition of medaka.

  1. Quantifiable Biomarkers of Normal Aging in the Japanese Medaka Fish (Oryzias latipes)

    PubMed Central

    Ding, Lingling; Kuhne, Wendy W.; Hinton, David E.; Song, Jian; Dynan, William S.

    2010-01-01

    Background Small laboratory fish share many anatomical and histological characteristics with other vertebrates, yet can be maintained in large numbers at low cost for lifetime studies. Here we characterize biomarkers associated with normal aging in the Japanese medaka (Oryzias latipes), a species that has been widely used in toxicology studies and has potential utility as a model organism for experimental aging research. Principal Findings The median lifespan of medaka was approximately 22 months under laboratory conditions. We performed quantitative histological analysis of tissues from age-grouped individuals representing young adults (6 months old), mature adults (16 months old), and adults that had survived beyond the median lifespan (24 months). Livers of 24-month old individuals showed extensive morphologic changes, including spongiosis hepatis, steatosis, ballooning degeneration, inflammation, and nuclear pyknosis. There were also phagolysosomes, vacuoles, and residual bodies in parenchymal cells and congestion of sinusoidal vessels. Livers of aged individuals were characterized by increases in lipofuscin deposits and in the number of TUNEL-positive apoptotic cells. Some of these degenerative characteristics were seen, to a lesser extent, in the livers of 16-month old individuals, but not in 6-month old individuals. The basal layer of the dermis showed an age-dependent decline in the number of dividing cells and an increase in senescence-associated β-galactosidase. The hearts of aged individuals were characterized by fibrosis and lipofuscin deposition. There was also a loss of pigmented cells from the retinal epithelium. By contrast, age-associated changes were not apparent in skeletal muscle, the ocular lens, or the brain. Significance The results provide a set of markers that can be used to trace the process of normal tissue aging in medaka and to evaluate the effect of environmental stressors. PMID:20949019

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

    PubMed

    Lee, Wenjau; Wang, Yun-Chi

    2015-01-01

    The use of artificial sweeteners (ASWs) has increased and become more widespread, and consequently ASWs have appeared in aquatic environments around the world. However, their safety to the health of humans and wildlife remains inconclusive. In this study, using medaka embryos (Oryzias latipes), we investigated developmental toxicity of aspartame (ASP) and saccharin (SAC). Since ASWs are often consumed with caffeine (CAF) and CAF with sucrose (SUC), we tested biological activities of these four substances and the mixtures of CAF with each sweetener. The embryos were exposed to ASP at 0.2 and 1.0 mM, SAC at 0.005 and 0.050 mM, CAF at 0.05 and 0.5 mM, or SUC at 29 and 146 mM, starting from less than 5 h post fertilization until hatch. Control embryos were treated with embryo solution only. Several endpoints were used to evaluate embryonic development. Some of the hatchlings were also tested for anxiety-like behavior with the white preference test. The results showed that all four substances and the mixtures of CAF with the sweeteners affected development. The most sensitive endpoints were the heart rate, eye density, and hatchling body length. The hatchlings of several treatment groups also exhibited anxiety-like behavior. We then used the Integrated Biological Response (IBR) as an index to evaluate the overall developmental toxicity of the substances. We found that the ranking of developmental toxicity was SAC > CAF > ASP > SUC, and there was a cumulative effect when CAF was combined with the sweeteners. PMID:26380162

  3. Differential developmental toxicity of naphthoic acid isomers in medaka (Oryzias latipes) embryos

    PubMed Central

    Carney, Michael W.; Erwin, Kyle; Hardman, Ron; Yuen, Bonny; Volz, David C.; Hinton, David E.; Kullman, Seth W.

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent pollutants that readily undergo biotic and abiotic conversion to numerous transformation products in rivers, lakes and estuarine sediments. Here we characterize the developmental toxicity of four PAH transformation products each structural isomers of hydroxynaphthoic acid: 1H2NA, 2H1NA, 2H3NA, and 6H2NA. Medaka fish (Oryzias latipes) embryos and eleutheroembryos were used to determine toxicity. A 96-well micro-plate format was used to establish a robust, statistically significant platform for assessment of early life stages. Individual naphthoic acid isomers demonstrated a rank order of toxicity with 1H2NA > 2H1NA > 2H3NA > 6H2NA being more toxic. Abnormalities of circulatory system were most pronounced including pericardial edema and tube heart. To determine if HNA isomers were AhR ligands, spatial-temporal expression and activity of CYP1A was measured via in vivo EROD assessments. qPCR measurement of CYP1A induction proved different between isomers dosed at respective concentrations affecting 50% of exposed individuals (EC50s). In vitro, all ANH isomers transactivated mouse AhR using a medaka CYP1A promoter specific reporter assay. Circulatory abnormalities followed P450 induction and response was consistent with PAH toxicity. A 96-well micro-plates proved suitable as exposure chambers and provided statistically sound evaluations as well as efficient toxicity screens. Our results demonstrate the use of medaka embryos for toxicity analysis thereby achieving REACH objectives for the reduction of adult animal testing in toxicity evaluations. PMID:18433798

  4. Stage-dependent ethoxyresorufin-O-deethylase (EROD) in vivo activity in medaka (Oryzias latipes) embryos.

    PubMed

    González-Doncel, Miguel; Carbonell, Gregoria; San Segundo, Laura; Sastre, Salvador; Beltrán, Eulalia M; Fernández-Torija, Carlos

    2015-09-01

    Using medaka (Oryzias latipes) embryos, this study aimed to quantitatively characterize the stage-dependent in vivo ethoxyresorufin-O-deethylase (EROD) as indicator of cytochrome P4501A (CYP1A) activity. Embryos were challenged for 24-h to an agonist (β-naphthoflavone [BNF], 2.5, 5, 10, and 20 μg L(-1)) or to its combination (2.5 μg L(-1)) with an antagonist (α-naphthoflavone [ANF], 25, 50, 100, and 200 μg L(-1)), initiated at four different developmental time points (1, 3, 6, and 9 d post-fertilization [dpf]). Respective induction and competitive inhibition were evaluated over fluorescent images of whole embryo (nonorgan-specific [NOS] EROD activity) and gallbladder (organ-specific [OS] EROD activity). Both flavonoids showed signs of stability in solution. Generally speaking, the mean fluorescence intensity (MFI) values for NOS EROD increased with BNF concentration and exposure challenge. BNF co-exposure with ⩾50 μg ANF L(-1) during the 1-2 and 3-4 dpf challenges lowered NOS EROD to undetectably induced levels. Significant increments in MFIs for OS-EROD were seen from exposures to ⩾2.5 μg BNF L(-1), peaking during the 6-7 dpf challenge regardless of BNF concentration. The simultaneous BNF/ANF incubation showed competitive inhibition for OS EROD activity, although levels were generally detectably induced during all challenges and at all ANF concentrations. The morphometric in vivo gallbladder analysis indicated significant dilation in the 10 dpf-old embryos co-exposed to BNF and 200 μg ANF L(-1). This quantitative approach can be used successfully at 4 dpf at the NOS-EROD or OS-EROD levels, although the NOS-EROD response was sensitive enough to induction or inhibition, even at 2 dpf.

  5. p53 Mutation suppresses adult neurogenesis in medaka fish (Oryzias latipes)

    SciTech Connect

    Isoe, Yasuko; Okuyama, Teruhiro; Taniguchi, Yoshihito; Kubo, Takeo; Takeuchi, Hideaki

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Progenitor migration is accompanied by an increase in their numbers in the adult brain. Black-Right-Pointing-Pointer p53 Mutation suppressed an increase in the number of the migrated progenitors. Black-Right-Pointing-Pointer The decreased progenitor number is not due to enhanced cell death. Black-Right-Pointing-Pointer p53 Mutation did not affect proliferation of stem cells. -- Abstract: Tumor suppressor p53 negatively regulates self-renewal of neural stem cells in the adult murine brain. Here, we report that the p53 null mutation in medaka fish (Oryzias latipes) suppressed neurogenesis in the telencephalon, independent of cell death. By using 5-bromo-29-deoxyuridine (BrdU) immunohistochemistry, we identified 18 proliferation zones in the brains of young medaka fish; in situ hybridization showed that p53 was expressed selectively in at least 12 proliferation zones. We also compared the number of BrdU-positive cells present in the whole telencephalon of wild-type (WT) and p53 mutant fish. Immediately after BrdU exposure, the number of BrdU-positive cells did not differ significantly between them. One week after BrdU-exposure, the BrdU-positive cells migrated from the proliferation zone, which was accompanied by an increased number in the WT brain. In contrast, no significant increase was observed in the p53 mutant brain. Terminal deoxynucleotidyl transferase (dUTP) nick end-labeling revealed that there was no significant difference in the number of apoptotic cells in the telencephalon of p53 mutant and WT medaka, suggesting that the decreased number of BrdU-positive cells in the mutant may be due to the suppression of proliferation rather than the enhancement of neural cell death. These results suggest that p53 positively regulates neurogenesis via cell proliferation.

  6. Rspo1-activated signalling molecules are sufficient to induce ovarian differentiation in XY medaka (Oryzias latipes)

    PubMed Central

    Zhou, Linyan; Charkraborty, Tapas; Zhou, Qian; Mohapatra, Sipra; Nagahama, Yoshitaka; Zhang, Yueguang

    2016-01-01

    In contrast to our understanding of testicular differentiation, ovarian differentiation is less well understood in vertebrates. In mammals, R-spondin1 (Rspo1), an activator of Wnt/β-catenin signaling pathway, is located upstream of the female sex determination pathway. However, the functions of Rspo1 in ovarian differentiation remain unclear in non-mammalian species. In order to elucidate the detailed functions of Rspo/Wnt signaling pathway in fish sex determination/differentiation, the ectopic expression of the Rspo1 gene was performed in XY medaka (Oryzias latipes). The results obtained demonstrated that the gain of Rspo1 function induced femininity in XY fish. The overexpression of Rspo1 enhanced Wnt4b and β-catenin transcription, and completely suppressed the expression of male-biased genes (Dmy, Gsdf, Sox9a2 and Dmrt1) as well as testicular differentiation. Gonadal reprograming of Rspo1-over-expressed-XY (Rspo1-OV-XY) fish, induced the production of female-biased genes (Cyp19a1a and Foxl2), estradiol-17β production and further female type secondary sexuality. Moreover, Rspo1-OV-XY females were fertile and produced successive generations. Promoter analyses showed that Rspo1 transcription was directly regulated by DM domain genes (Dmy, the sex-determining gene, and Dmrt1) and remained unresponsive to Foxl2. Taken together, our results strongly suggest that Rspo1 is sufficient to activate ovarian development and plays a decisive role in the ovarian differentiation in medaka. PMID:26782368

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

    PubMed

    Lee, Wenjau; Wang, Yun-Chi

    2015-01-01

    The use of artificial sweeteners (ASWs) has increased and become more widespread, and consequently ASWs have appeared in aquatic environments around the world. However, their safety to the health of humans and wildlife remains inconclusive. In this study, using medaka embryos (Oryzias latipes), we investigated developmental toxicity of aspartame (ASP) and saccharin (SAC). Since ASWs are often consumed with caffeine (CAF) and CAF with sucrose (SUC), we tested biological activities of these four substances and the mixtures of CAF with each sweetener. The embryos were exposed to ASP at 0.2 and 1.0 mM, SAC at 0.005 and 0.050 mM, CAF at 0.05 and 0.5 mM, or SUC at 29 and 146 mM, starting from less than 5 h post fertilization until hatch. Control embryos were treated with embryo solution only. Several endpoints were used to evaluate embryonic development. Some of the hatchlings were also tested for anxiety-like behavior with the white preference test. The results showed that all four substances and the mixtures of CAF with the sweeteners affected development. The most sensitive endpoints were the heart rate, eye density, and hatchling body length. The hatchlings of several treatment groups also exhibited anxiety-like behavior. We then used the Integrated Biological Response (IBR) as an index to evaluate the overall developmental toxicity of the substances. We found that the ranking of developmental toxicity was SAC > CAF > ASP > SUC, and there was a cumulative effect when CAF was combined with the sweeteners.

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

    EPA Science Inventory

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

  9. Effects of antimony on aquatic organisms (Larva and embryo of Oryzias latipes, Moina macrocopa, Simocephalus mixtus, and Pseudokirchneriella subcapitata).

    PubMed

    Nam, Sun-Hwa; Yang, Chang-Yong; An, Youn-Joo

    2009-05-01

    Antimony is widespread in aquatic environment. Trivalent forms of antimony are known to be more toxic than other chemical species of antimony. In the present study, antimony potassium tartrate (APT), the trivalent inorganic forms of antimony, was selected as a test antimony compound due to its high water solubility. The effects of antimony on Japanese medaka (Oryzias latipes), planktonic crustacea (Moina macrocopa and Simocephalus mixtus), and green algae (Pseudokirchneriella subcapitata) were evaluated. Larval survival and the embryonic development were measured for fish assay. APT was less toxic to larval medaka (24-h LC50, 261; 48-h LC50, 238 mg L(-1)). Simocephalus mixtus was killed by very low concentrations of APT (24-h LC50, 4.92 mg L(-1)), and antimony was also toxic to Moina macrocopa (24-h LC50, 12.83 mg L(-1)). Toxicities of APT to S. mixtus and Moina macrocopa were about 50 and 20 times more toxic to Oryzias latipes larvae, respectively, in terms of 24-h LC50 value. Growth inhibition of Pseudokirchneriella subcapitata was observed in the presence of APT (72-h EC50, 206 mg L(-1)). This study demonstrated that APT is more toxic to planktonic crustacea than fish and green algae, and planktonic crustacea appears a better indicator of antimony pollution in aquatic environment. PMID:19264343

  10. Early life-stage mortalities of Japanese medaka (Oryzias latipes) exposed to polychlorinated diphenyl ethers

    SciTech Connect

    Metcalfe, C.D.; Metcalfe, T.L.; Cormier, J.A.; Huestis, S.Y.; Niimi, A.J.

    1997-08-01

    Polychlorinated diphenyl ethers (PCDEs) are a group of compounds that resemble polychlorinated dibenzofurans in structure that have been detected at ppb concentrations in fish from the Great Lakes. The objective of this project was to determine the toxicological significance of PCDE residues in fish. PCDE congener 77 (3,3{prime},4,4{prime}-tetrachlorodiphenyl ether), congener 71 (2,3{prime},4{prime},6-tetrachlorodiphenyl ether), congener 118 (2,3{prime}4,4{prime},5-pentachlorodiphenyl ether), and congener 105 (2,3,3{prime},4,4{prime}-pentachlorodiphenyl) were tested for toxicity with early life stages (ELS) of Japanese medaka, Oryzias latipes. These embryotoxicity data showed that the mono-ortho congeners 105 and 118 and the non-ortho congener 77 were embryotoxic to medaka. However, the toxic equivalency factors (TEFs) estimated for congeners 105, 77, and 118 relative to 2,3,7,8-TCDD were relatively low at 0.00056, 0.00003, and 0.00001, respectively. PCDE compounds were isolated in a fraction prepared from a bulk extract of Lake Ontario lake trout. In this fraction, congeners 99 (2,2{prime},4,4{prime},5-pentaCDE), 153 (2,2{prime},4,m4{prime},5,5{prime}-hexaCDE), 154 (2,2{prime},4,4{prime},5,6{prime}-hexaCDE), and 163 (2,3,3{prime},4{prime},5,6-hexaCDE) comprised 81.3% of total PCDEs, while congeners 77, 71, 118, and 105 comprised only 1.1% of total PCDEs. The LC50 for embryotoxicity of this fraction was equivalent to 15.5 ng/ml of total PCDEs. Toxicopathic lesions noted in medaka embryos exposed to either individual PCDEs or the lake trout extract included vascular hemorrhage but no edematous lesions. Medaka fry did not exhibit symptoms of hyperexcitability prior to death, as has been noted for ELS of lake trout exhibiting swim-up syndrome. These data indicate that PCDEs in Lake Ontario lake trout have the potential to induce toxic effects in early life stages of fish.

  11. Stage sensitivity of eggs of the teleost Oryzias latipes to cadmium exposure

    SciTech Connect

    Michibata, H.; Nojima, Y.; Kojima, M.K.

    1987-04-01

    The stage sensitivity of eggs of the teleost Oryzias latipes to cadmium exposure was examined. First, using eggs at the blastula stage, the proper concentration of cadmium to which the eggs should be exposed was estimated. The eggs were, therefore, exposed to cadmium solutions ranging from 10.0 to 300.0 mg Cd/liter for 1 hr, and then they were transferred to cadmium-free medium. The cumulative mortality of the eggs was estimated by counting dead eggs within 24 hr. Mortality (1.1 +/- 0.7%) indistinguishable from that of the control (1.0 +/- 0.2%) was obtained in the solution of 10.0 mg Cd/liter. Relatively higher mortalities of 13.2 +/- 1.5, 18.0 +/- 1.0, and 20.7 +/- 3.1% could be seen in the solutions containing 50.0, 100.0, and 150.0 mg Cd/liter, respectively. Moreover, the exposure of the eggs to 200.0 and 300.0 mg Cd/liter increased mortality rates to 32.0 +/- 0.8 and 34.7 +/- 2.4%, respectively. Consequently, the concentration of 200.0 mg Cd/liter was selected for examining the stage sensitivity. Eggs at 11 different developmental stages were exposed to cadmium at a concentration of 200.0 mg Cd/liter for 1 hr. The mortalities obtained at the 4- to 16-cell stage, 32-cell stage, and morula stage were 99.2 +/- 1.0, 97.4 +/- 2.6, and 89.6 +/- 10.6%, respectively. With the progress of embryonic development, the eggs became more resistant to cadmium toxicity. After the morula stage, the mortalities decreased abruptly. In order to ascertain whether the change in mortalities of the eggs with development was related to the amount of cadmium combined with the eggs, the cadmium content was determined. In contrast to the remarkable change in the stage sensitivity to cadmium, the curve of cadmium content in the eggs remained constant at about 520 ng/egg throughout the experimental period.

  12. Development of the steroidogenic capacity of medaka (Oryzias latipes) ovarian follicles during vitellogenesis and oocyte maturation.

    PubMed

    Sakai, N; Iwamatsu, T; Yamauchi, K; Nagahama, Y

    1987-06-01

    Developmental changes in the steroidogenic capacity of medaka, Oryzias latipes, ovarian follicles at 12 different stages during vitellogenesis and oocyte maturation were examined using 18-hr incubations. Medaka were acclimated to conditions of 26 degrees on a lighting regime of 14 hr light and 10 hr dark. Under these conditions, females usually spawn daily within 1 hr of the onset of light. The process of vitellogenesis and oocyte maturation occurs within 72 hr, the breakdown of the germinal vesicle (GVBD) and ovulation being completed at 6 and 1 hr, respectively, before the expected time of spawning. Vitellogenic follicles between 32 and 16 hr before spawning produced large amounts of estradiol-17 beta spontaneously and in response to partially purified chum salmon gonadotropin (SGA) or pregnant mare's serum gonadotropin (PMSG). However, postvitellogenic follicles between 12 and 4 hr before spawning showed very little evidence of estradiol-17 beta production. By contrast, basal concentrations of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-diOHprog) remained very low in follicles during vitellogenesis and were elevated in those collected during oocyte maturation; there was a close relationship between the medium concentration of 17 alpha,20 beta-diOH-prog and the percentage GVBD in the oocytes. 17 alpha,20 beta-DiOHprog production in response to PMSG was very low in follicles during early and mid-vitellogenesis and increased in those collected at 28 hr before spawning, a time which coincided with the first acquisition of the ability of the follicles to undergo maturation in response to gonadotropin. These results clearly demonstrate that a distinct shift from the secretion of predominantly estradiol-17 beta to the secretion of 17 alpha,20 beta-diOHprog occurs in the medaka ovarian follicle immediately prior to oocyte maturation. Considering the potency of 17 alpha,20 beta-diOHprog for the induction of oocyte maturation in vitro, these results

  13. Glycoprotein from the liver constitutes the inner layer of the egg envelope (zona pellucida interna) of the fish, Oryzias latipes

    SciTech Connect

    Hamazaki, T.S.; Nagahama, Y.; Iuchi, I.; Yamagami, K.

    1989-05-01

    A glycoprotein from the liver, which shares epitopes with chorion (egg envelope or zona pellucida) glycoproteins, is present only in the spawning female fish, Oryzias latipes, under natural conditions. This spawning female-specific (SF) substance is distinct from vitellogenin but closely resembles a major glycoprotein component, ZI-3, of the inner layer (zona radiata interna) of the ovarian egg envelope with respect to some biochemical and immunochemical characteristics. Here we report that the (/sup 125/I)SF substance, injected into the abdominal cavity of the spawning female fish, was rapidly transported by the blood circulation into the ovary and incorporated into the inner layer of egg envelope of the growing oocytes. The result strongly suggests that the SF substance from the liver is a precursor substance of the major component, ZI-3, of the inner layer of egg envelope in the fish.

  14. Studies on the mechanism of circus movement in dissociated embryonic cells of a teleost, Oryzias latipes: fine-structural observations.

    PubMed

    Fujinami, N

    1976-10-01

    The fine structure of lobopodia in dissociated embryonic cells of the freshwater fish, Oryzias latipes, was observed with the electron microscope in order to understand the mechanism of the circus movements which they display. Dense material (grandular or fibrillar) is present in the zone between the lobopodium and the endoplasm, as well as in the cortical layer around the cell circumference. The direction of lobopodial movement is related to the distribution of this dense material. The band between the lobopodium and the endoplasm is conspicuous and is connected to the cortical dense layer around the cell periphery at the advancing front of the lobopodium, while the dense material is usually almost absent beneath the cell membrane in the anterior region of the lobopodium. The band between lobopodium and endoplasm is blurred or disrupted near the hind end of the lobopodiu, where the peripheral dense layer is well developed. In situ localization of actin/heavy meromyosin complexes in the cell showed that the dense material has actin-like properties. Cytochalasin B(0-5 mug/ml) induced constriction of the neck of the bleb, shrinkage of the endoplasm, and herniation of the endoplasmic contents to the enlarged hemispherical bleb, and thus arrested the circus movement. On the basis of these results, an hypothesis concerning the mechanism of circus movement is proposed and discussed.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  16. 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.

  17. Toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid on freshwater macroinvertebrates (Daphnia magna and Moina macrocopa) and fish (Oryzias latipes).

    PubMed

    Ji, Kyunghee; Kim, Younghee; Oh, Sorin; Ahn, Byeongwoo; Jo, Hyunye; Choi, Kyungho

    2008-10-01

    Because of their global distribution, persistence, and tendency to bioaccumulate, concerns about perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are growing. We determined the toxicity of PFOS and PFOA in several freshwater organisms, including two cladocerans, Daphnia magna and Moina macrocopa, and the teleost Oryzias latipes. In general, PFOS is approximately 10 times more toxic than PFOA in these organisms. In M. macrocopa, the median lethal concentration (LC50) was 17.95 mg/L for PFOS and 199.51 mg/L for PFOA. Moina macrocopa exhibited greater sensitivity than D. magna to both perfluorinated compounds in both acute and chronic exposures. In the 48-h acute toxicity test, M. macrocopa was approximately two times more sensitive than D. magna. In the 7-d chronic toxicity test, M. macrocopa showed significant reproductive changes at 0.31 mg/L for PFOS, which was approximately seven times lower than the effect concentrations observed over the 21-d exposure in D. magna. Two-generation fish toxicity tests showed that parental exposure to both compounds affected the performance of offspring. Unexposed progeny-generation (F1) fish exhibited elevated mortality and histopathological changes that were correlated with exposure in the parental generation (F0). Continuous exposure from F0 through F1 generations increased the extent of adverse effects. Considering the persistent nature of PFOS and PFOA, more research is required to determine potential consequences of long-term exposure to these compounds in aquatic ecosystems. PMID:18593212

  18. Developmental toxicity and DNA damage from exposure to parking lot runoff retention pond samples in the Japanese Medaka (Oryzias latipes)

    PubMed Central

    Colton, Meryl D.; Kwok, Kevin W.H.; Brandon, Jennifer A.; Warren, Isaac H.; Ryde, Ian T.; Cooper, Ellen M.; Hinton, David E.; Rittschof, Daniel; Meyer, Joel N.

    2015-01-01

    Parking lot runoff retention ponds (PLRRP) receive significant chemical input, but the biological effects of parking lot runoff are not well understood. We used the Japanese medaka (Oryzias latipes) as a model to study the toxicity of water and sediment samples from a PLRRP in Morehead City, NC. Medaka exposed in ovo to a dilution series of PLRRP water had increased odds of death before hatching, but not teratogenesis or delayed hatching. Next, we adapted a long-amplicon quantitative PCR (LA-QPCR) assay for DNA damage for use with the Japanese medaka. We employed LA-QPCR to test the hypotheses that PLRRP water and sediments would cause nuclear and mitochondrial DNA damage with and without full-spectrum, natural solar radiation. Fluoranthene with and without natural sunlight was a positive control for phototoxic polycyclic aromatic hydrocarbon-induced DNA damage. Fluoranthene exposure did not result in detectable DNA damage by itself, but in combination with sunlight caused significant DNA damage to both genomes. PLRRP samples caused DNA damage to both genomes, and this was not increased by sunlight exposure, suggesting the DNA damage was unlikely the result of PAH phototoxicity. We report for the first time that PLRRP-associated pollutants cause both nuclear and mitochondrial DNA damage, and that fluoranthene-mediated phototoxicity results in similar levels of damage to the nuclear and mitochondrial genomes. These effects may be especially significant in sensitive marine ecosystems. PMID:24816191

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

    NASA Astrophysics Data System (ADS)

    Shimomura, S.; Ijiri, K.

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

  20. Use of the Japanese medaka (Oryzias latipes) and guppy (Poecilia reticulata) in carcinogenesis testing under national toxicology program protocols.

    PubMed

    Hawkins, William E; Walker, William W; Fournie, John W; Manning, C Steve; Krol, Rena M

    2003-01-01

    A need exists for whole animal toxicity, mutagenesis, and carcinogenesis models that are alternative to the traditional rodent test models and 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 used, is valuable as a comparison species. Both species are easy to maintain and handle in the laboratory and there is a large body of background information on their responsiveness to a range of classes of carcinogens. There are considerable data on the occurrence of background diseases and on spontaneous neoplastic lesions, both of which occur relatively rarely. With few modifications, the medaka and guppy are amenable to carcinogenicity testing under the rigid standards established by the National Toxicology Program (NTP) for rodent tests. The advantages of the small fish in carcinogenesis studies are best realized in long-term studies that involve environmentally realistic exposures. Studies to identify chronic effects can be conducted in about 12 months, near the life span of medaka in our laboratory. Practically, 9-month studies are optimal but shorter study cycles and a variety of exposure/growout and initiation/promotion scenarios are available. Studies on 3 compounds tested in medaka under NTP protocols are under review and preliminary analysis indicates that chronic carcinogenicity bioassays with medaka, guppy, and potentially with other small fish species are feasible and scientifically valid. PMID:12597435

  1. Multiwall Carbon Nanotube-Induced Apoptosis and Antioxidant Gene Expression in the Gills, Liver, and Intestine of Oryzias latipes

    PubMed Central

    Lee, Jin Wuk; Choi, Young Chul; Kim, Rosa; Lee, Sung Kyu

    2015-01-01

    Multiwall carbon nanotubes (MWCNTs) have many attractive properties with potential applications in various fields. Despite their usefulness, however, the associated waste can be hazardous to the environment. To examine adverse effects in aquatic environments, Oryzias latipes were exposed to MWCNTs dispersed in water for 14 days and apoptosis and antioxidant gene expression were observed. This work showed that in gills exposed to 100 mg/L MWCNTs for 4 days, there was significant p53, caspase-3 (Cas3), caspase-8 (Cas8), and caspase-9 (Cas9) gene expression relative to the controls, while catalase (CAT) and glutathione-S-transferase (GST) expression were reduced. At 14 days, CAT, GST, and metallothionein (MT) were induced significantly in the gills and Cas3, Cas8, and Cas9 were induced in the liver. No significant gene induction was seen in intestine. Intracellular reactive oxygen species (ROS) were increased significantly only at 14 days. Histologically, no apoptosis was observed with exposure to 100 mg/L MWCNTs for 21 days. The gills were more sensitive to MWCNT toxicity than the other organs. Males had higher apoptosis gene induction than females. These results demonstrated that MWCNTs could cause apoptosis in a manner influenced by tissue and gender in aqueous environments. PMID:26146619

  2. Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.

    PubMed

    Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

    2011-02-01

    Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity. PMID:21072839

  3. Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.

    PubMed

    Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

    2011-02-01

    Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity.

  4. Effects of post-Hurricane Katrina New Orleans (LA, USA) sediments on early development of the Japanese medaka (Oryzias latipes).

    PubMed

    Liebl, Andrea L; Granados, Lisa H; Zhang, Qiang; Wang, Guangdi; Mielke, Howard W; Gonzales, Christopher R; Ennis, Don G; Rees, Bernard B

    2008-12-01

    When Hurricane Katrina struck the U.S. Gulf Coast, levees surrounding New Orleans, Louisiana, USA, were breached, leading to widespread flooding of the city and potential contamination from industrial spills, residential sources, and redistribution of pre-existing pollutants. We chemically characterized sediment samples from five New Orleans locations and used early development and mutagenesis in Japanese medaka (Oryzias latipes) as metrics of the toxic effects of these sediments. Sediment samples were analyzed for organohalogen pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and metals. One month after Hurricane Katrina, four of the five sites had unsafe concentrations of arsenic and one or more pesticides, pesticide metabolites, or polycyclic aromatic hydrocarbons. Medaka embryonic mortality and time to hatching both increased during exposure to aqueous extracts of sediments, with the greatest toxicity observed for the most heavily contaminated sediment. Exposure to sediment extracts did not, however, result in significantly elevated rates of mutagenesis. When the most contaminated site was resampled 4.5 months later, the sediment had lower contaminant concentrations and fewer deleterious effects on medaka development. Using the medaka bioassay, therefore, we demonstrate toxic effects of post-Hurricane Katrina sediments immediately following the storm, with some amelioration over time of contaminant concentrations and their negative biological effects.

  5. [{sup 3}H]-2,3,7,8-TCDD uptake and elimination kinetics of medaka (Oryzias latipes)

    SciTech Connect

    Schmieder, P.; Lothenbach, D.; Tietge, J.; Erickson, R.; Johnson, R.

    1995-10-01

    Uptake and elimination rate constants for [{sup 3}H]-2,3,7,8-tetrachlorodibenzo-p-dioxin ([{sup 3}H]TCDD) were estimated by exposing medaka (Oryzias latipes) to [{sup 3}H]TCDD in flowing water with no solvent carriers. Uptake was determined from body-burdens measured on exposure days 0, 2, 4, 6, 10, and 12. Elimination was quantified for whole fish after 28, 90, and 175 d in uncontaminated water. Medaka accumulated [{sup 3}H]TCDD at a rapid rate, achieving residues 24,000 times the water concentration after 12 d, with no indication of approach to steady state. After 6 months in uncontaminated water, the pg TCDD/g decreased by 69%, much of the decrease due to growth dilution as evidenced by only a 47% decrease in the pg TCDD/fish. Uptake and elimination rate constant (2,300 ml/g/d and 0.0045/d, respectively) were estimated by fitting a one-compartment, linear, mass-balance model to the data, adjusting for growth rate. The experimental design, including solvent-free delivery of [{sup 3}H]TCDD, exposure at concentrations below maximum water solubility, and measurement of fish growth and lipid content during a 6-month elimination phase, resulted in a predicted steady-state bioconcentration factor (BCF) for medaka of 510,000, a number considerably higher than previously reported for dioxin BCFs. Kinetic parameters were used to successfully predict TCDD BCF in medaka exposed independently.

  6. Quantitative analysis of fish schooling behavior with different numbers of medaka ( Oryzias latipes) and goldfish ( Carassius auratus)

    NASA Astrophysics Data System (ADS)

    Leem, Joo-Baek; Jeon, Wonju; Yun, Chi-Young; Lee, Sang-Hee

    2012-12-01

    Fish form schools of various sizes, according to species or environmental conditions, to attain several advantages, such as protection from predators or to improve efficiency in searching for prey. Thus, quantifying the mechanisms of how group size affects schooling behavior may contribute to better understanding fish biology and the evolution of the collective behavior of fishes. In the present study, we explored how school size affected the behavior of medaka ( Oryzias latipes) and goldfish ( Carassius auratus). Size groups of 10 to 40 individuals were placed in a circular aquarium (100 cm diameter, 30 cm height, 5 cm water depth) and videoed for 4 hours. Eight to 10 video clips of 3 seconds in length for each group size were evaluated for 6 physical parameters of fish schooling behavior. Regardless of species, the mean distance among individuals increased with increasing school size. However, due to variations in certain physical parameters, the schooling pattern of goldfish was more elongated than medaka, possibly related to body size, or indicating species-specific differences in schooling characteristics. Our experimental datasets could be incorporated into theoretical mathematical models of fish schooling behavior, by contributing new information about school size and species differences.

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

    PubMed

    Richter, Catherine A; Papoulias, Diana M; Whyte, Jeffrey J; Tillitt, Donald E

    2016-09-01

    Atrazine has been implicated in reproductive dysfunction of exposed organisms, and previous studies documented decreased egg production in Japanese medaka (Oryzias latipes) and fathead minnows (Pimephales promelas) during 30-d to 38-d exposures to 0.5 µg/L, 5 µg/L, and 50 µg/L atrazine. The authors evaluated possible mechanisms underlying the reduction in egg production. Gene expression in steroidogenesis pathways and the hypothalamus-pituitary-gonad axis of male and female fish was measured. Atrazine did not significantly induce gonad aromatase (cyp19a1a) expression. An atrazine-induced shift in the number of females in an active reproductive state was observed. Expression of the egg maturation genes vitellogenin 1 (vtg1) and zona pellucida glycoprotein 3.1 (zp3.1) in medaka females was correlated and had a bimodal distribution. In both species, females with low vtg1 or zp3.1 expression also had low expression of steroidogenesis genes in the gonad, estrogen receptor in the liver, and gonadotropins in the brain. In the medaka, the number of females per tank that had high expression of zp3.1 was significantly correlated with egg production per tank. The number of medaka females with low expression of zp3.1 increased significantly with atrazine exposure. Thus, the decline in egg production observed in response to atrazine exposure may be the result of a coordinated downregulation of genes required for reproduction in a subset of females. Environ Toxicol Chem 2016;35:2230-2238. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. PMID:26792394

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

    SciTech Connect

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

    2008-10-15

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

  9. Insight into the transgenerational effect of benzo[a]pyrene on bone formation in a teleost fish (Oryzias latipes).

    PubMed

    Seemann, Frauke; Peterson, Drew R; Witten, P Eckhard; Guo, Bao-Sheng; Shanthanagouda, Adamane H; Ye, Rui R; Zhang, Ge; Au, Doris W T

    2015-12-01

    Recent cross-generational studies in teleost fish have raised the awareness that high levels of benzo[a]pyrene (BaP) could affect skeletal integrity in the directly exposed F0 and their F1-F2. However, no further details were provided about the causes for abnormalities on the molecular and cellular level and the persistence of such sub-organismal impairments at the transgenerational scale (beyond F2). Adult Oryzias latipes were exposed to 1μg/L BaP for 21days. The F1-F3 were examined for skeletal deformities, histopathological alterations of vertebral bodies and differential expression of key genes of bone metabolism. Significant increase of dorsal-ventral vertebral compression was evident in ancestrally exposed larvae. Histopathological analysis revealed abnormal loss of notochord sheath, a lack of notochord epithelial integrity, reduced bone tissue and decreased osteoblast abundance. A significant downregulation of ATF4 and/or osterix and a high biological variability of COL10, coupled with a significant deregulation of SOX9a/b in the F1-F3 suggest that ancestral BaP exposure most likely perturbed chordoblasts, chondroblast and osteoblast differentiation, resulting in defective notochord sheath repair and rendering the vertebral column more vulnerable to compression. The present findings provide novel molecular and cellular insights into BaP-induced transgenerational bone impairment in the unexposed F3. From the ecological risk assessment perspective, BaP needs to be regarded as a transgenerational skeletal toxicant, which exerts a far-reaching impact on fish survival and fitness. Given that basic mechanisms of cartilage/bone formation are conserved between medaka and mammals, the results may also shed light on the potential transgenerational effect of BaP on the genesis of skeletal diseases in humans. PMID:26456900

  10. 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.

  11. Transcriptional responses in Japanese medaka (Oryzias latipes) exposed to binary mixtures of an estrogen and anti-estrogens.

    PubMed

    Sun, Liwei; Shao, Xiaolu; Hu, Xinhua; Chi, Jian; Jin, Yuanxiang; Ye, Weihong; Fu, Zhengwei

    2011-10-01

    Determining ecotoxicological risks of exposure to mixtures of endocrine disrupting chemicals (EDCs) remains a daunting challenge in environmental toxicology. Recently, some studies have illustrated that transcriptional profiling of genes offers the potential to identify the chemical causation of effects that are induced by exposure to complex mixtures. In the present study, the transcriptional responses of a set of genes involved in the hypothalamic-pituitary-gonadal (HPG, or HPG[L]-liver) axis of Japanese medaka (Oryzias latipes) were systematically examined after treatment with a combination of an estrogen (17α-ethinylestradiol [EE2], 20 ng/L) and two model anti-estrogens, the aromatase inhibitor (AI) letrozole (LET) and the selective estrogen-receptor modulator (SERM) tamoxifen (TAM), at three concentrations (30, 100 and 300 μg/L) for 72 h. The data presented demonstrate that although gene transcription analyses increase our mechanistic understanding of the modes of action (MOAs) of EDCs, the characteristic of most genes altered by a certain single chemical exposure may not be useful for diagnostic chemical causation in a mixture exposure situation. For example, the induction of one vitellogenin gene (VTG1) transcription caused by EE2 in male fish was effectively blocked after exposure to a combination of EE2 and LET but not EE2 and TAM. Moreover, the responses in gene transcription to coexposure were elicited partially in a nonmonotonic concentration-dependent manner. Therefore, the application of transcriptional profiling of genes for screening complex environmental samples should be further evaluated until biomarker gene responses are robust and sensitive enough to properly assess the complex interactions.

  12. Alteration of gene expression profiles in the brain of Japanese medaka (Oryzias latipes) exposed to KC-400 or PCB126.

    PubMed

    Nakayama, Kei; Sei, Naomi; Oshima, Yuji; Tashiro, Kosuke; Shimasaki, Yohei; Honjo, Tsuneo

    2008-01-01

    Polychlorinated biphenyls (PCBs) are known as neurotoxic chemicals and possibly alter animal behavior. We previously reported that PCB-exposure induced abnormal schooling behavior in Japanese medaka (Oryzias latipes). This abnormal behavior might be caused by the functional alteration of central or terminal nervous system. To understand the mechanism(s) of behavioral change by PCB-exposure, we analyzed the gene expression profiles in the brain of medaka exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB126) or a PCB mixture (Kanechlor-400: KC-400) using a cDNA microarray that we constructed. Twelve FLF-II strain medaka (six individuals per treatment) were dietary exposed to PCB126 (0.01 microg/g b.w./day) or KC-400 (1 microg/g b.w./day) for three weeks. For the control, six fish were fed a control diet. After the exposure period, fish were dissected, and the brain samples were collected. The samples from control fish were pooled and used as a common reference in the microarray experiment. Microarray data were normalized by the LOWESS method, and we screened the genes whose expression levels were altered more than 1.5-fold. Gene expression profiling showed 97 down-regulated and 379 up-regulated genes in the brain of medaka exposed to PCB126. KC-400 exposure suppressed 15 genes and induced 266 genes in medaka brain. Among these genes, the expression levels of 7 and 188 genes were commonly down- or up-regulated, respectively in both treatment groups. On the other hand, 31 gene expressions were significantly different between PCB126 and KC-400 treatment groups, and three out of 31 genes were received opposite effects. In addition, the microarray data showed that thyroid hormone-responsive genes were up-regulated by PCB-exposure, which may imply that PCBs or their metabolites mimic thyroid hormone effects in the brain of PCB-exposed medaka. PMID:18374953

  13. Fish multigeneration test with preliminary short-term reproduction assay for estrone using Japanese medaka (Oryzias latipes).

    PubMed

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

    2015-01-01

    The most potent chemicals potentially causing adverse effects on fish species are estrogens in human waste.Sewage is a source of these estrogens and it is difficult to reduce. In particular, although the bioactivity of estrone is estimated to be about half of that of estradiol, multiple studies report that more than 100 ng l(–1) of estrone can be detected in urban rivers, including discharges from sewage treatment works; approximately two times as high as estradiol. Few studies have been conducted to investigate the long-term effects of estrone on wildlife; therefore, we conducted fish multigeneration test using Japanese medaka (Oryzias latipes). Medaka were exposed to estrone for 27 weeks across three generations in environmentally relevant concentrations, being 5.74, 11.4, 24.0, 47.1 and 91.4 ng l(–1). No effects on reproduction were observed in the first generation; however, a decline in egg production and fertility was observed in the second generation exposed to 91.4 ng l(–1) estrone, which is lower than some known environmental concentrations in urban environments. Furthermore, histopathological abnormalities were observed in the third generation exposed to both 47.1 and 91.4 ng l(–1), suggesting that estrone possibly exerts severe effects on the third or later generations. However, appearances of testis–ova were observed in the second and third generation they were not consistent with actual effects on reproduction, notwithstanding the testis-ovais regarded as the key evidence for endocrine disruption. Accordingly, we consider that qualitative measurement of abnormalities using histopathological observations is required for appropriate evaluation of endocrine disruption. PMID:25580481

  14. Adduct formation of 7,12-dimethylbenz(a)anthracene in the embryo of the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Liu, H.; Cooper, K.R.

    1995-12-31

    DNA adduct formation of 7,1 2-dimethylbenz(a)anthracene (DMBA) in vivo in the Japanese medaka embryo were investigated using {sup 32}P-postlabeling analysis. 1-compounds (endogenous adducts) were not observed in the Japanese medaka embryo on days 4 (prior to liver formation), 6 (liver/swim bladder) or 10 (prior to hatch) of development. The level of DMBA:DNA adducts were concentration-dependent over the range of 0.625 ppm (Total Adducts 0.05707 pmol/mg of DNA) to 2.50 ppm (0.43341 pmol/mg of DNA) and decreased at 5.00 ppm (0.25338 pmol/mg of DNA) after medaka embryos were exposed to DMBA for 6 days from the day of fertilization. The decrease in DMBA:DNA adducts at 5.00 ppm was probably due to embryo toxicity (78% death). The level of DMBA:DNA adducts formed from the embryos exposed to DMBA for 24 hr decreased as the stage of development increased: day 4 > day 6 > day 10; 0.0262, 0.0179, 0.0129 pmol/mg of DNA, respectively. The level of DMBA:DNA adducts increased as the length of exposure increased: 4 day < 6 day < 10 day; 0.0233, 0.0614, 0.1502, respectively. There was both a time and dose dependence to the number of adducts detected. The data presented demonstrated the development of DM BA-DNA adducts in the developing Japanese medaka (Oryzias latipes) and the lack of I-compounds.

  15. Non invasive in vivo investigation of hepatobiliary structure and function in STII medaka (Oryzias latipes): methodology and applications

    PubMed Central

    Hardman, Ron C; Kullman, Seth W; Hinton, David E

    2008-01-01

    Background A novel transparent stock of medaka (Oryzias latipes; STII), recessive for all pigments found in chromatophores, permits transcutaneous imaging of internal organs and tissues in living individuals. Findings presented describe the development of methodologies for non invasive in vivo investigation in STII medaka, and the successful application of these methodologies to in vivo study of hepatobiliary structure, function, and xenobiotic response, in both 2 and 3 dimensions. Results Using brightfield, and widefield and confocal fluorescence microscopy, coupled with the in vivo application of fluorescent probes, structural and functional features of the hepatobiliary system, and xenobiotic induced toxicity, were imaged at the cellular level, with high resolution (< 1 μm), in living individuals. The findings presented demonstrate; (1) phenotypic response to xenobiotic exposure can be investigated/imaged in vivo with high resolution (< 1 μm), (2) hepatobiliary transport of solutes from blood to bile can be qualitatively and quantitatively studied/imaged in vivo, (3) hepatobiliary architecture in this lower vertebrate liver can be studied in 3 dimensions, and (4) non invasive in vivo imaging/description of hepatobiliary development in this model can be investigated. Conclusion The non-invasive in vivo methodologies described are a unique means by which to investigate biological structure, function and xenobiotic response with high resolution in STII medaka. In vivo methodologies also provide the future opportunity to integrate molecular mechanisms (e.g., genomic, proteomic) of disease and toxicity with phenotypic changes at the cellular and system levels of biological organization. While our focus has been the hepatobiliary system, other organ systems are equally amenable to in vivo study, and we consider the potential for discovery, within the context of in vivo investigation in STII medaka, as significant. PMID:18838008

  16. The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

    PubMed Central

    Colman, Jamie R; Ramsdell, John S

    2003-01-01

    Brevetoxins are produced by the red tide dinoflagellate Karenia brevis. The toxins are lipophilic polyether toxins that elicit a myriad of effects depending on the route of exposure and the target organism. Brevetoxins are therefore broadly toxic to marine and estuarine animals. By mimicking the maternal route of exposure to the oocytes in finfish, we characterized the adverse effects of the type B brevetoxin brevetoxin-3 (PbTx-3) on embryonic fish development and survival. The Japanese rice fish, medaka (Oryzias latipes), was used as the experimental model in which individual eggs were exposed via microinjection to various known concentrations of PbTx-3 dissolved in an oil vehicle. Embryos injected with doses exceeding 1.0 ng/egg displayed tachycardia, hyperkinetic twitches in the form of sustained convulsions, spinal curvature, clumping of the erythrocytes, and decreased hatching success. Furthermore, fish dosed with toxin were often unable to hatch in the classic tail-first fashion and emerged head first, which resulted in partial hatches and death. We determined that the LD(50) (dose that is lethal to 50% of the fish) for an injected dose of PbTx-3 is 4.0 ng/egg. The results of this study complement previous studies of the developmental toxicity of the type A brevetoxin brevetoxin-1 (PbTx-1), by illustrating in vivo the differing affinities of the two congeners for cardiac sodium channels. Consequently, we observed differing cardiovascular responses in the embryos, wherein embryos exposed to PbTx-3 exhibited persistent tachycardia, whereas embryos exposed to PbTx-1 displayed bradycardia, the onset of which was delayed. PMID:14644667

  17. Gene-specific of endocannabinoid receptor 1 (cnr1a) by ethanol probably leads to the development of fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish (Oryzias latipes) embryogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Developmental ethanol exposure is able to induce Fetal Alcohol Spectrum Disorder (FASD) phenotypes in Japanese rice fish (Oryzias latipes). This study investigated possible differential expression of cannabinoid receptor (cnr) mRNAs during Japanese rice fish embryogenesis and variability to ethanol-...

  18. P-NITROPHENOL METABOLISM BY JAPANESE MEDAKA (ORYZIAS LATIPES) LIVER MICROSOMES AND S-9 FRACTION: ADDITIONAL EVIDENCE FOR THE EXISTENCE OF A CYP2E1-LIKE ISOFORM IN TELEOSTS

    EPA Science Inventory

    Liver microsomes and S-9 fraction of Japanese medaka (Oryzias latipes) metabolized the CYP2E1 specific substrate, p-nitrophenol (PNP), to a single hydroxylated product, 4-nitrocatechol. The use of liver S-9 fraction proved to be a viable alternative to liver microsomes and allowe...

  19. Analysis of the Ush2a Gene in Medaka Fish (Oryzias latipes)

    PubMed Central

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

    2013-01-01

    Patients suffering from Usher syndrome (USH) exhibit sensorineural hearing loss, retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. USH is the most common genetic disorder affecting hearing and vision and is included in a group of hereditary pathologies associated with defects in ciliary function known as ciliopathies. This syndrome is clinically classified into three types: USH1, USH2 and USH3. USH2 accounts for well over one-half of all Usher cases and mutations in the USH2A gene are responsible for the majority of USH2 cases, but also for atypical Usher syndrome and recessive non-syndromic RP. Because medaka fish (Oryzias latypes) is an attractive model organism for genetic-based studies in biomedical research, we investigated the expression and function of the USH2A ortholog in this teleost species. Ol-Ush2a encodes a protein of 5.445 aa codons, containing the same motif arrangement as the human USH2A. Ol-Ush2a is expressed during early stages of medaka fish development and persists into adulthood. Temporal Ol-Ush2a expression analysis using whole mount in situ hybridization (WMISH) on embryos at different embryonic stages showed restricted expression to otoliths and retina, suggesting that Ol-Ush2a might play a conserved role in the development and/or maintenance of retinal photoreceptors and cochlear hair cells. Knockdown of Ol-Ush2a in medaka fish caused embryonic developmental defects (small eyes and heads, otolith malformations and shortened bodies with curved tails) resulting in late embryo lethality. These embryonic defects, observed in our study and in other ciliary disorders, are associated with defective cell movement specifically implicated in left-right (LR) axis determination and planar cell polarity (PCP). PMID:24086419

  20. Endocrine disruption and consequences of chronic exposure to ibuprofen in Japanese medaka (Oryzias latipes) and freshwater cladocerans Daphnia magna and Moina macrocopa.

    PubMed

    Han, Sunyoung; Choi, Kyungho; Kim, Jungkon; Ji, Kyunghee; Kim, Sunmi; Ahn, Byeongwoo; Yun, Junheon; Choi, Kyunghee; Khim, Jong Seong; Zhang, Xiaowei; Giesy, John P

    2010-07-01

    Despite frequent detection of ibuprofen in aquatic environments, the hazards associated with long-term exposure to ibuprofen have seldom been investigated. Ibuprofen is suspected of influencing sex steroid hormones through steroidogenic pathways in both vertebrates and invertebrates. In this study, the effect of ibuprofen on sex hormone balance and the associated mechanisms was investigated in vitro by use of H295R cells. We also conducted chronic toxicity tests using freshwater fish, Oryzias latipes, and two freshwater cladocerans, Daphnia magna and Moina macrocopa, for up to 144 and 21d of exposure, respectively. Ibuprofen exposure increased 17beta-estradiol (E2) production and aromatase activity in H295R cells. Testosterone (T) production decreased in a dose-dependent manner. For D. magna, the 48 h immobilization EC50 was 51.4 mg/L and the 21 d reproduction NOEC was <1.23 mg/L; for M. macrocopa, the 48 h immobilization EC50 was 72.6 mg/L and the 7d reproduction NOEC was 25mg/L. For O. latipes, 120 d survival NOEC was 0.0001 mg/L. In addition, ibuprofen affected several endpoints related to reproduction of the fish, including induction of vitellogenin in male fish, fewer broods per pair, and more eggs per brood. Parental exposure to as low as 0.0001 mg/L ibuprofen delayed hatching of eggs even when they were transferred to and cultured in clean water. Delayed hatching is environmentally relevant because this may increase the risk of being predated. For O. latipes, the acute-to-chronic ratio of ibuprofen was estimated to be greater than 1000. Overall, relatively high acute-to-chronic ratio and observation of reproduction damage in medaka fish at environmentally relevant ranges of ibuprofen warrant the need for further studies to elucidate potential ecological consequences of ibuprofen contamination in the aquatic environment. PMID:20236711

  1. Medaka (Oryzias latipes) as a sentinel species for aquatic animals: Medaka cells exhibit a similar genotoxic response as North Atlantic right whale cells★

    PubMed Central

    Wise, John Pierce; Wise, Sandra S.; Goodale, Britton C.; Shaffiey, Fariba; Kraus, Scott; Walter, Ronald B.

    2015-01-01

    Hexavalent chromium (Cr(VI)) is emerging as a major concern for aquatic environments, particularly marine environments. Medaka (Oryzias latipes) has been used as a model species for human and aquatic health, including the marine environment, though few studies have directly compared toxicological responses in medaka to humans or other aquatic species. We used a medaka fin cell line to compare the genotoxic response of medaka to Cr(VI) to the response observed in North Atlantic right whale cells to see if responses in medaka were similar to those of other aquatic species, particularly aquatic mammals. We used the production of chromosomal aberrations as a measure of genotoxicity. We found that in medaka cells, concentrations of 1, 5 and 10 μM sodium chromate damaged 17, 32 and 43% of metaphases, respectively and these same concentrations 1, 2.5, 5 and 10 μM sodium chromate damaged 14, 24 and 49% of metaphases, respectively, in North Atlantic right whale lung cells and 11, 32 and 41% of metaphases, respectively, in North Atlantic right whale testes cells. These data show that genotoxic responses in medaka are comparable to those seen in North Atlantic right whale cells, consistent with the hypothesis that medaka are a useful model for other aquatic species. PMID:18930840

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

    PubMed

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

    2013-12-01

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

  3. Effect of chronic exposure to acetaminophen and lincomycin on Japanese medaka (Oryzias latipes) and freshwater cladocerans Daphnia magna and Moina macrocopa, and potential mechanisms of endocrine disruption.

    PubMed

    Kim, PanGyi; Park, Yena; Ji, Kyunghee; Seo, Jihyun; Lee, Sangwoo; Choi, Kyunghee; Kho, Younglim; Park, Jeongim; Choi, Kyungho

    2012-09-01

    Chronic toxicity of acetaminophen and lincomycin were evaluated using freshwater organisms including two crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). H295R, a human adrenal cell was also used to understand the effects on steroidogenesis. In 21 d D. magna exposure, survival NOEC was found at 5.72 mg L(-1) and no reproduction related effects were noted at this level of exposure to acetaminophen, while 21 d survival or growth effects were not observed even at the highest exposure levels (153 mg L(-1)) for lincomycin. In the chronic fish toxicity test, significant reduction in juvenile survival was observed at 30 d post-hatch (dph) at 95 mg L(-1) of acetaminophen, and 0.42 mg L(-1) of lincomycin. After the exposure to both pharmaceuticals, vitellogenin levels tended to increase in male fish at 90 dph. In the eggs which were prenatally exposed to 9.5 mg L(-1) of acetaminophen, reduced hatchability was observed. The results of H295R cell assay showed that both pharmaceuticals could alter steroidogenic pathway and increase estrogenicity. Endocrine disruption potentials and their ecological implication may deserve further studies. Our observations suggest however that ecological risks of both pharmaceuticals are negligible at the concentrations currently found in the environment. PMID:22560975

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

    PubMed

    Li, Shibin; Pan, Xuan; Wallis, Lindsay K; Fan, Zhaoyang; Chen, ZuLiang; Diamond, Stephen A

    2014-10-01

    With a dramatic rise in complexity, needs of nanotoxicology research go beyond simple forms of nanomaterials. This study compared the phototoxicity of nano-TiO2 and graphene-TiO2 nanocomposite (GNP). GNP was synthesized based on a hydrothermal method, which simultaneously performed the reduction of graphene oxide and nano-TiO2 loading. A series of acute toxicity tests of nano-TiO2, graphene and GNP was performed on two aquatic organisms, Daphnia magna and Oryzias latipes. Fast and substantial agglomeration and sedimentation of nanoparticles in test media and surface attachment of nano-TiO2 and GNP on D. magna surface was observed. Similar phototoxicity of nano-TiO2 and GNP for both species existed, though compared with nano-TiO2, GNP had a 2.3-fold increase in visible light photocatalytic ROS generation. In summary, this study demonstrated the significance of illumination spectrum, particle behavior, and species sensitivity on nanophototoxicity, and the needs for research on increasingly sophisticated functional materials.

  5. Effect of hypergravity on expression of the immediate early gene, c-fos, in central nervous system of medaka (Oryzias latipes)

    NASA Astrophysics Data System (ADS)

    Sayaka, Shimomura-Umemura; Ijiri, Kenichi

    2006-01-01

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

  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. Exposure to the synthetic FXR agonist GW4064 causes alterations in gene expression and sublethal hepatotoxicity in eleutheroembryo medaka (Oryzias latipes).

    PubMed

    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.

  8. Developmental regulation of neuroligin genes in Japanese ricefish (Oryzias latipes) embryogenesis maintains the rhythm during ethanol-induced fetal alcohol spectrum disorder.

    PubMed

    Haron, Mona H; Khan, Ikhlas A; Dasmahapatra, Asok K

    2014-01-01

    Although prenatal alcohol exposure is the potential cause of fetal alcohol spectrum disorder (FASD) in humans, the molecular mechanism(s) of FASD is yet unknown. We have used Japanese ricefish (Oryzias latipes) embryogenesis as an animal model of FASD and reported that this model has effectively generated several phenotypic features in the cardiovasculature and neurocranial cartilages by developmental ethanol exposure which is analogous to human FASD phenotypes. As FASD is a neurobehavioral disorder, we are searching for a molecular target of ethanol that alters neurological functions. In this communication, we have focused on neuroligin genes (nlgn) which are known to be active at the postsynaptic side of both excitatory and inhibitory synapses of the central nervous system. There are six human NLGN homologs of Japanese ricefish reported in public data bases. We have partially cloned these genes and analyzed their expression pattern during normal development and also after exposing the embryos to ethanol. Our data indicate that the expression of all six nlgn genes in Japanese ricefish embryos is developmentally regulated. Although ethanol is able to induce developmental abnormalities in Japanese ricefish embryogenesis comparable to the FASD phenotypes, quantitative real-time PCR (qPCR) analysis of nlgn mRNAs indicate unresponsiveness of these genes to ethanol. We conclude that the disruption of the developmental rhythm of Japanese ricefish embryogenesis by ethanol that leads to FASD may not affect the nlgn gene expression at the message level.

  9. Combined Transcriptomic and Proteomic Approach to Identify Toxicity Pathways in Early Life Stages of Japanese Medaka (Oryzias latipes) Exposed to 1,2,5,6-Tetrabromocyclooctane (TBCO).

    PubMed

    Sun, Jianxian; Tang, Song; Peng, Hui; Saunders, David M V; Doering, Jon A; Hecker, Markus; Jones, Paul D; Giesy, John P; Wiseman, Steve

    2016-07-19

    Currently, the novel brominated flame retardant 1,2,5,6-tetrabromocyclooctane (TBCO) is considered a potential replacement for hexabromocyclododecane (HBCD). Therefore, use of TBCO could increase in the near future. To assess potential toxicological risks to aquatic organisms, embryos of Japanese medaka (Oryzias latipes) were exposed to 10, 100, or 1000 μg/L TBCO from 2 h postfertilization until 1 day post-hatch. TBCO accumulated in embryos in the order of 0.43-1.3 × 10(4)-fold, and the rate constant of accumulation was 1.7-1.8 per day. The number of days to hatch and the hatching success of embryos exposed to the medium and the greatest concentrations of TBCO were impaired. Responses of the transcriptome (RNA-seq) and proteome were characterized in embryos exposed to 100 μg/L TBCO because this was the least concentration of TBCO that caused an effect on hatching. Consistent with effects on hatching, proteins whose abundances were reduced by exposure to TBCO were enriched in embryo development and hatching pathways. Also, on the basis of the responses of transcriptome and proteome, it was predicted that TBCO might impair vision and contraction of cardiac muscle, respectively, and these effects were confirmed by targeted bioassays. This study provided a comprehensive understanding of effects of TBCO on medaka at early life stages and illustrated the power of "omics" to explain and predict phenotypic responses to chemicals. PMID:27322799

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

    PubMed

    Li, Shibin; Pan, Xuan; Wallis, Lindsay K; Fan, Zhaoyang; Chen, ZuLiang; Diamond, Stephen A

    2014-10-01

    With a dramatic rise in complexity, needs of nanotoxicology research go beyond simple forms of nanomaterials. This study compared the phototoxicity of nano-TiO2 and graphene-TiO2 nanocomposite (GNP). GNP was synthesized based on a hydrothermal method, which simultaneously performed the reduction of graphene oxide and nano-TiO2 loading. A series of acute toxicity tests of nano-TiO2, graphene and GNP was performed on two aquatic organisms, Daphnia magna and Oryzias latipes. Fast and substantial agglomeration and sedimentation of nanoparticles in test media and surface attachment of nano-TiO2 and GNP on D. magna surface was observed. Similar phototoxicity of nano-TiO2 and GNP for both species existed, though compared with nano-TiO2, GNP had a 2.3-fold increase in visible light photocatalytic ROS generation. In summary, this study demonstrated the significance of illumination spectrum, particle behavior, and species sensitivity on nanophototoxicity, and the needs for research on increasingly sophisticated functional materials. PMID:25048889

  11. Telomere attrition and restoration in the normal teleost Oryzias latipes are linked to growth rate and telomerase activity at each life stage

    PubMed Central

    Hatakeyama, Hitoshi; Yamazaki, Hiromi; Nakamura, Ken-Ichi; Izumiyama-Shimomura, Naotaka; Aida, Junko; Suzuki, Hiroetsu; Tsuchida, Shuichi; Matsuura, Masaaki; Takubo, Kaiyo; Ishikawa, Naoshi

    2016-01-01

    Telomere shortening occurs when cells divide, both in vitro and in vivo. On the other hand, telomerase is able to maintain telomere length in cells by adding TTAGGG repeats to the ends of telomeres. However, the interrelationships existing among telomere length, telomerase activity and growth in vertebrates remain to be clarified. In the present study we measured telomere length (terminal restriction fragment length), telomerase activity and body growth of Oryzias latipes from the embryo stage until senescence. During the rapid growth stage (age 0–7 months), telomeres shortened in parallel with decreasing telomerase activity. Then, during adolescence (age 7 months – 1 year), telomeres lengthened quickly as growth slowed and telomerase activity increased. In the adult stage (age 1–4 years) characterized by little growth, telomerase activity decreased gradually and telomeres shortened. Our data indicate that telomere attrition and restoration are linked to growth and telomerase activity, and suggest that critical loss of telomere homeostasis is associated with mortality in this animal. PMID:26789258

  12. Sublethal exposure of extracted sediments induces hepatic cellular alterations in Medaka, Oryzias latipes: An assay for testing the presence of carcinogens

    SciTech Connect

    Chai, D.; Cormier, S.M. )

    1988-09-01

    Small aquarium fish species and embryos have many positive attributes as test animals. They require little space and therefore, generate less toxic waste especially when coupled with single, short term exposures. In addition to these advantages, Oryzias latipes, the medaka, offers additional benefits. The medakas genetics and biology have been well studied, reproduction can be easily controlled with an appropriate light cycle, embryos mature rapidly and the species has been shown to be sensitive to carcinogens. For these reasons the medaka was selected for these experiments to determine the relative toxicity and carcinogenicity of contaminated sediments via a single, short term exposure. Two known carcinogens, Aflatoxin B{sub 1} (AFB{sub 1}) and Aroclor 1254 (PCB), and six environmental samples were tested. The selection of sediment sampling sites was based on a report generated from the Pittsburgh District Dredged Material Analysis Program. Four sites along the Monogahela River and two on the Ohio River where sampled with an Eckman dredge. The chemical analyses conducted by the Corps have shown the presence of various toxic chemicals including polyaromatic hydrocarbons and heavy metals.

  13. 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.

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

    PubMed

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

    2016-01-01

    Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations. PMID:26606134

  15. Oral Exposure of PBDE-47 in Fish: Toxicokinetics and Reproductive Effects in Japanese Medaka (Oryzias latipes) and Fathead Minnows (Pimephales promelas)

    SciTech Connect

    Muirhead, Elisabeth K.; Skillman, Ann D.; Hook, Sharon E.; Schultz, Irv R.

    2006-01-15

    The toxicokinetics of 2,2,4,4-tetrabromodipohenyl ether (PBDE-47) was studied in the Japanese Medaka (Oryzias latipes) after a single oral exposure followed by termination at specific time points. The effects of repeated oral exposure to PBDE-47 on reproductive performance was assessed using a pair breeding experimental design with fathead minnows (Pimephales promelas) given daily PBDE-47 exposures for 25 days, during which fecundity was measured as an indicator of reproductive performance. Medaka and fathead minnows were orally exposed to PBDE-47 by bioencapsulation in brine shrimp, Artemia sp. In the medaka studies, measurable levels of PBDE-47 were detected in the carcass within 0.25 hr with peak levels occurring at 8 hrs. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 hrs after dosing. Assimilation of the bioencapsulated dose was at least 80% and may well approach 100 %. The PBDE-47 concentration-time profile was fitted to a one-compartment clearance-volume toxicokinetic model and the model-predicted values for elimination half-life was determined to be 281 hrs and the first order absorption rate constant was (Ka) = 0.26 hr 1. In the fathead minnow study, egg laying in the PBDE-treated breeding pairs stopped after 10 days. The condition factor of PBDE-treated males was significantly reduced (P < 0.011) compared with control males, whereas no significant difference was observed in females. Histological examination revealed a greater than 50% reduction in mature sperm in PBDE-47 exposed minnows compared to controls. Collectively, these results suggest PBDE-47 is selectively toxic to sexually mature male fathead minnows.

  16. Temperature-dependent sex determination in Hd-rR medaka Oryzias latipes: gender sensitivity, thermal threshold, critical period, and DMRT1 expression profile.

    PubMed

    Hattori, R S; Gould, R J; Fujioka, T; Saito, T; Kurita, J; Strüssmann, C A; Yokota, M; Watanabe, S

    2007-01-01

    The developmental time and thermal threshold for temperature-dependent sex determination (TSD), gender differences in temperature sensitivity, the fertility of thermally sex reversed fish, and the effect of temperature on the expression of two major sex determination/differentiation genes (DMY/DMRT1bY and DMRT1) were examined in the Hd-rR strain of medaka, Oryzias latipes. Fertilized eggs were exposed from either shortly after fertilization (8-16 cells; embryonic stages 5-6) or from middle embryogenesis (heart development stage; stage 36) until hatching to temperatures ranging from 17 degrees C to 34 degrees C. Secondary sexual characteristics, gonadal histology, progeny testing, sex-linked body coloration and gene expression were used to determine phenotypic and genotypic sex. Sex determination was unaffected by low or high temperatures in genotypic (XY) males. In contrast, genotypic (XX) females treated from stages 5-6 showed increasing rates of sex reversal into phenotypic males at temperatures above 27 degrees C up to 100% at 34 degrees C. Thermal manipulation of sex was ineffective after stage 36, indicating that gonadal fate in medaka is determined considerably earlier than histological differentiation (stage 39). High temperature induced DMRT1 expression in genotypic females, which was observed already from stage 36. Sex-reversed males had histologically normal testes, were capable of sexual courtship and, with the exception of fish from 34 degrees C, sired viable progeny when mating with fertile females. These results clarify the pattern of TSD in medaka and provide important clues to understand the mechanism of sex determination in this species. They also suggest that a brief exposure to high temperature early in life could impair the fertility of medaka as adults.

  17. Time-dependent transcriptional profiles of genes of the hypothalamic-pituitary-gonadal axis in medaka (Oryzias latipes) exposed to fadrozole and 17beta-trenbolone.

    PubMed

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

    2008-12-01

    Both the anabolic androgen 17beta-trenbolone (TRB) and the aromatase inhibitor fadrozole (FAD) can cause decreased plasma concentrations of estrogen (E2) and reduce fecundity of fish. However, the underlying mechanisms and the molecular pathways involved are largely unknown. The present study was designed to assess time-dependent effects of FAD and TRB on the transcriptional responses of the hypothalamic-pituitary-gonadal (HPG) axis of Japanese medaka (Oryzias latipes). Fourteen-week-old Japanese medaka were exposed to 50 microg FAD/L or 2 microg TRB/L in a 7-d static renewal test, and the expression profiles of 36 HPG axis genes were measured by means of a medaka HPG real-time reverse-transcription polymerase chain reaction array after 8 h, 32 h, or 7 d of exposure. Exposure to TRB or FAD caused lesser fecundity of Japanese medaka and down-regulated transcription of vitellogenin and choriogenin (CHG) gene expression in the liver of females. Exposure to FAD for 8 h resulted in an 8-fold and 71-fold down-regulation of expression of estrogen receptor alpha and choriogenin L (CHG L), respectively, in female liver. 17beta-Trenbolone caused similar down-regulation of these genes, but the effects were not observed until 32 h of exposure. These results support the hypothesis that FAD reduces plasma E2 more quickly by inhibiting aromatase enzyme activity than does TRB, which inhibits the production of the E2 precursor testosterone. Exposure to FAD and TRB resulted in rapid (after 8 h) down-regulation of luteinizing hormone receptor and low-density-lipoprotein receptor in the testis to compensate for excessive androgen levels. Overall, the molecular responses observed in the present study differentiate the mechanisms of the reduced fecundity by TRB and FAD.

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

    PubMed

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

    2015-02-01

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

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

    PubMed

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

    2010-10-15

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

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

    USGS Publications Warehouse

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

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X?? ?? SD) at log I=1.96 (photopic) varied from 37.2 ?? 1.6 cycles/s in young adults to 18.6 ?? 1.6 cycles/s in young larvae 10 days posthatch. At log I= - 2.54 (scotopic), flicker fusion thresholds varied from 5.8 ?? 0.7 cycles/s in young adults to 1.7 ?? 0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche. ?? 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

  1. High efficiency production of germ-line transgenic Japanese medaka (Oryzias latipes) by electroporation with direct current-shifted radio frequency pulses.

    PubMed

    Hostetler, Heather A; Peck, Stephanie L; Muir, William M

    2003-08-01

    Although there have been several studies showing the production of transgenic fish through electroporation techniques, success rates have been low and few studies show germ-line integration and expression. When electroporation has been successful, the device used is no longer commercially available. The goal of this experiment was to find an alternative efficient method of generating transgenic Japanese medaka (Oryzias latipes) using a commercially available electroporation device. The Gene Pulser II and RF module (Bio-Rad Laboratories, USA), along with two reporter gene constructs, were used. In contrast to other electroporation devices, which are based on a single pulse with exponential decay or square wave technology, the Gene Pulser II incorporates a direct current (DC)-shifted radio frequency (RF) signal. With this technique, over 1000 embryos can be electroporated in less than 30 min. The plasmid pCMV-SPORT-beta-gal (Invitrogen, USA) was used in the supercoiled form to optimize parameters for gene transfer into single-celled embryos, and resulted in up to 100% somatic gene transfer. Similar conditions were used to generate fish transgenic for both the pCMV-EGFP plasmid (Clontech, USA) and a cytomegalovirus (CMV) driven phytase-EGFP construct. The conditions used were a voltage of 25 V, a percent modulation of 100%, a radio frequency of 35 kHz, a burst duration of 10 ms, 3 bursts, and a burst interval of 1.0 s. Seventy percent of the embryos electroporated with the pCMV-EGFP construct survived to sexual maturity, and of those, 85% were capable of passing the transgene on to their offspring. Transgenic second generation back-crossed (BC2) fry were subjected to Southern blot analysis, which confirmed germ-line integration, and observation for green fluorescence protein, which confirmed protein expression. DC-shifted RF pulses are effective and efficient in the production of transgenic medaka, and germ-line integration and expression can be achieved without

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

    PubMed

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

    2016-01-01

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

  3. Two states of active spermatogenesis switch between reproductive and non-reproductive seasons in the testes of the medaka, Oryzias latipes.

    PubMed

    Iwasaki, Yuko; Ohkawa, Keiko; Sadakata, Hisato; Kashiwadate, Akiko; Takayama-Watanabe, Eriko; Onitake, Kazuo; Watanabe, Akihiko

    2009-08-01

    Seasonal change in spermatogenesis was examined in the restricted spermatogonium-type testes of a teleost, Oryzias latipes. Histological observation revealed that the number of each stage of germ cells during most of the non-reproductive season, from October to January (O-J period) was nearly half of that during the reproductive season, from May to July (M-J period), except for type B spermatogonia (B-gonia), which was actually equal. As a result, the ratio of primary spermatocytes (P-cytes) to B-gonia was remarkably small in the O-J period. Despite the differences between both time periods, the proliferative activity of type A spermatogonia (A-gonia), B-gonia, or P-cytes was at a similar level in both periods. Moreover, in cultured testes treated with bromodeoxyuridine as a cell-lineage tracer, P-cytes differentiated to spermatids in 11-15 days in both M-J and O-J periods. These indicate that spermatogenesis is active in each period at a different state. In the spermatogenic testis, A-gonial proliferation was maintained by human follicle stimulating hormone/luteinizing hormone in culture. Whereas cell death of B-gonia and/or P-cytes gradually increased in the M-J period in spite of those cells being constant in population sizes. In transition to the O-J period, A-gonia and P-cytes first decreased, which was accompanied by a decrease in proliferative activity of A-gonia and relative increase of dead cells from B-gonia and/or P-cytes against live P-cytes. These suggest that A-gonial proliferation and cell death of B-gonia and/or P-cytes that is induced coordinately with B-gonial differentiation are critical for the spermatogenic control.

  4. Endocrine-disrupting potentials of equine estrogens equilin, equilenin, and their metabolites, in the medaka Oryzias latipes: in silico and DNA microarray studies.

    PubMed

    Uchida, Masaya; Ishibashi, Hiroshi; Yamamoto, Ryoko; Koyanagi, Akiko; Kusano, Teruhiko; Tominaga, Nobuaki; Ishibashi, Yasuhiro; Arizono, Koji

    2015-09-01

    Although several previous studies have demonstrated the presence of equine estrogens in the aquatic environment, limited data are currently available on the endocrine-disrupting potentials in fish and the risks they pose to aquatic organisms. To investigate the interactions of major equine estrogens equilin (Eq) and equilenin (Eqn), as well as their metabolites 17α-dihydroequilin, 17β-dihydroequilin, 17α-dihydroequilenin and 17β-dihydroequilenin, with the estrogen receptor α (ERα) of medaka (Oryzias latipes), a three-dimensional model of the ligand-binding domain (LBD) of ERα was built in silico, and docking simulations were performed. The docking simulation analysis indicated that the interaction of 17β-dihydroequilenin with the ERα LBD is the most potent, followed by those of 17α-dihydroequilin and 17β-dihydroequilin, whereas those of Eq and Eqn were least potent. We further analyzed gene expression profiles in the livers of male medaka exposed to Eq and Eqn. A DNA microarray representing 6000 genes revealed that 24-h exposure to Eq and Eqn (100 ng/L) upregulated the expression of 6 and 34 genes in the livers of males, respectively. Genes upregulated by Eq included the estrogenic biomarker genes vitellogenins and choriogenins, suggesting the estrogenic potential of Eq. In contrast, Eqn exposure upregulated several cancer-related genes, such as mediator complex subunit 16 and RAS oncogene family members, suggesting a carcinogenic potential for Eqn. These results suggest that equine estrogens may have not only endocrine-disrupting potentials via the ERα signaling pathway but also carcinogenic potency in male medaka.

  5. Japanese medaka (Oryzias latipes) embryo assay for developmental toxicity incorporating individual embryo incubations: Evaluations of controls, a pure compound (BaP), soil extracts, and stream effluents

    SciTech Connect

    Hull, C.G.

    1993-01-01

    A non-indigenous, but useful fish species has been largely overlooked by organizations preparing protocols for toxicity testing in research and environmental regulation. The Japanese medaka (Oryzias latipes) has been used in basic and applied research in the United States and Japan for many years. All life-history stages have been used and studied, including numerous different types of embryo and embryo-larval assays. However, a medaka embryo assay has yet to be recommended by the American Society for Testing and Materials, the United States Environmental Protection Agency or the American Public Health Association for use as a test species in water quality control. The authors have developed and refined methods for evaluating toxicity and abnormalities in embryos exposed to contaminants in a variety of media. Individual embryos exposed to benzo[a]pyrene showed both increased mortalities and abnormalities. In the two field applications, individual embryos were exposed to: (1) soil extracts from two hydrocarbon-contaminated sites on U.S. Army Kwajalein Atoll, in the General Republic of the Marshall Islands, or (2) water samples from ten sites on East Fork Poplar Creek, in Oak Ridge, TN, a stream that originates inside the DOE Y-12 Plant. The two soil extracts were from diesel fuel-contaminated soil; treated embryos showed significant responses ranging from increased mortalities to abnormalities and developmental delays. The stream has a history of industrial contamination, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and heavy metals, (particularly mercury); other typical industrial discharges (i.e. chlorine, ammonia, and nitrates) are also present at some sites. Treatment groups showed high mortality and dose-dependent mortality in diluted samples compared to control and reference water samples. This study demonstrates the flexibility of this medaka embryo assay for assessing the toxicity of complex environmental sites.

  6. Influence of sediment composition on PAH toxicity using zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes) embryo-larval assays.

    PubMed

    Perrichon, Prescilla; Le Bihanic, Florane; Bustamante, Paco; Le Menach, Karyn; Budzinski, Hélène; Cachot, Jérôme; Cousin, Xavier

    2014-12-01

    Due to hydrophobic and persistent properties, polycyclic aromatic hydrocarbons (PAHs) have a high capacity to accumulate in sediment. Sediment quality criteria, for the assessment of habitat quality and risk for aquatic life, include understanding the fate and effects of PAHs. In the context of European regulation (REACH and Water Framework Directive), the first objective was to assess the influence of sediment composition on the toxicity of two model PAHs, benzo[a]pyrene and fluoranthene using 10-day zebrafish embryo-larval assay. This procedure was undertaken with an artificial sediment in order to limit natural sediment variability. A suitable sediment composition might be then validated for zebrafish and proposed in a new OECD guideline for chemicals testing. Second, a comparative study of toxicity responses from this exposure protocol was then performed using another OECD species, the Japanese medaka. The potential toxicity of both PAHs was assessed through lethal (e.g., survival, hatching success) and sublethal endpoints (e.g., abnormalities, PMR, and EROD) measured at different developmental stages, adapted to the embryonic development time of both species. Regarding effects observed for both species, a suitable artificial sediment composition for PAH toxicity testing was set at 92.5 % dry weight (dw) silica of 0.2-0.5-mm grain size, 5 % dw kaolin clay without organic matter for zebrafish, and 2.5 % dw blond peat in more only for Japanese medaka. PAH bioavailability and toxicity were highly dependent on the fraction of organic matter in sediment and of the K ow coefficients of the tested compounds. The biological responses observed were also dependent of the species under consideration. Japanese medaka embryos appeared more robust than zebrafish embryos for understanding the toxicity of PAHs following a sediment contact test, due to the longer exposure duration and lower sensitivity of sediment physical properties.

  7. Photoactivated polycyclic aromatic hydrocarbon toxicity in medaka (Oryzias latipes) embryos: relevance to environmental risk in contaminated sites.

    PubMed

    Diamond, Stephen A; Mount, David R; Mattson, Vincent R; Heinis, Larry J; Highland, Terry L; Adams, Andy D; Simcik, Matthew F

    2006-11-01

    The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoactivated toxicity in medaka (Orvzias latipes) embryos was determined experimentally and then compared with ultraviolet-A (UV-A; 320-400 nm) radiation exposures in a PAH-contaminated field site. The dose metric, J/cm2/ microg fluoranthene/g egg wet weight, provided the means to estimate risk as the depth where the LD50 level would be exceeded at realistic field PAH concentrations, based on estimates of UV-A exposure. The estimates were made using 30 years of solar radiation data for Duluth (MN, USA) and measurements of water-column UV-A transmittance in a PAH-contaminated field site. Medaka embryo failure was strongly related to tissue PAH concentration and UV-A exposure. The LD50 was estimated to be 12.64 J/cm2/ microg fluoranthene/g egg wet weight; the 95% confidence interval was 8.46 to 19.7 J/cm2/microg fluoranthene/g egg wet weight. Embryo failures were characterized by undifferentiated cell proliferation that occurred very early in development. No partial effects or embryo/larval malformations were observed. Estimates of the depth at which the LD50 would be exceeded in the contaminated field site ranged from 10.7 cm (clear-sky conditions and lowest attenuation) to 0.0 cm (cloudy conditions and highest attenuation). Similar calculations were done using water-column attenuation estimates from 12 sites across the Great Lakes (USA). For these, the depths at which the LD50 would be exceeded ranged from 0.00 to 271.6 cm under the conditions described above. These results suggest that PAH phototoxicity may be a risk factor in specific contaminated sites, and they provide a framework for assessing that risk. PMID:17089726

  8. Toxicity of C{sub 10}-, C{sub 11}-, C{sub 12}-, and C{sub 14}-polychlorinated alkanes to Japanese medaka (Oryzias latipes) embryos

    SciTech Connect

    Fisk, A.T.; Tomy, G.T.; Muir, D.C.G.

    1999-12-01

    Japanese medaka (Oryzias latipes) eggs were exposed to aqueous concentrations of six polychlorinated n-alkane (PCA) standards (C{sub 10}H{sub 15.5}Cl{sub 6.5}, C{sub 10}H{sub 15.3}Cl{sub 6.7}, C{sub 11}H{sub 18.4}Cl{sub 5.6}, C{sub 12}H{sub 19.5}Cl{sub 6.5}, C{sub 14}H{sub 24.9}Cl{sub 5.1}, and C{sub 14}H{sub 23.3}Cl{sub 6.7}) of known carbon chain length and chlorine content to assess their toxicity. Eggs were also exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to act as a positive control. Chlorinated paraffins are complex industrial products for which there is a lack of toxicological data on individual congeners. High aqueous concentrations of C{sub 10}H{sub 15.5}Cl{sub 6.5} and C{sub 10}H{sub 15.3}Cl{sub 6.7} caused 100% mortality in eggs, but no other significant mortalities or lesions were observed at lower concentrations or in any eggs exposed to the other PCAs. Larvae from eggs exposed to high concentrations of the C{sub 10}-, C{sup 11}- and C{sub 12}-PCAs were extremely lethargic or did not move, although a heart beat was present. The concentrations in these exposures and the tissue concentrations of the larvae were at levels that should elicit narcosis. Concentrations of the C{sub 14}-PCAs in larvae did not reach narcotic levels, and larvae in these exposures appeared normal with no signs of narcosis. The TCDD was found to be extremely embryotoxic, consistent with past work using Japanese medaka eggs. The ratio of LC50 to TCDD to the LC50 of the PCAs, based on acute toxicity and TCDD results, were all <0.0001, and most were <0.000001. These results suggest that the acute mechanism of toxicity of lower chlorinated, short (C{sub 10--13}) and medium (C{sub 14--18}) carbon chain PCAs is narcosis and that chlorine substitution on the terminal carbons of PCAs does not significantly increase nor decrease the toxicity of C{sub 10} and C{sub 14}-PCAs. However, additional work is needed to assess a greater range of PCAs as well as their sublethal effects and

  9. Isomer-specific accumulation of perfluorooctanesulfonate from (N-ethyl perfluorooctanesulfonamido)ethanol-based phosphate diester in Japanese Medaka (Oryzias latipes).

    PubMed

    Peng, Hui; Zhang, Shiyi; Sun, Jianxian; Zhang, Zhong; Giesy, John P; Hu, Jianying

    2014-01-21

    While (N-ethyl perfluorooctanesulfonamido)ethanol (FOSE) -based phosphate diester (diSPAP) has been proposed as a candidate precursor of perfluorooctanesulfonate (PFOS), its potential biotransformation to PFOS has not been verified. Metabolism of diSPAP was investigated in Japanese medaka ( Oryzias latipes ) after exposure in water for 10 days, followed by 10 days of depuration. Branched isomers of diSPAP (B-diSPAP) were preferentially enriched in medaka exposed to diSPAP, with the proportion of branched isomers (BF) ranging from 0.56 to 0.80, which was significantly greater than that in the water to which the medaka were exposed (0.36) (p < 0.001). This enrichment was due primarily to preferential uptake of B-diSPAP. PFOS together with perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (NEtFOSA), 2-(perfluorooctanesulfonamido)acetic acid (FOSAA), NEtFOSAA, FOSE, and NEtFOSE were detected in medaka exposed to diSPAP, which indicated the potential for biotransformation of diSPAP to PFOS via multiple intermediates. Due to preferential metabolism of branched isomers, FOSAA and PFOSA exhibited greater BF values (>0.5) than those of NEtFOSA, NEtFOSAA, and NEtFOSE (<0.2). Such preferential metabolism of branched isomers along the primary pathway of metabolism and preferential accumulation of B-diSPAP led to enrichment of branched PFOS (B-PFOS) in medaka. Enrichment of B-PFOS was greater for 3-, 4-, and 5-perfluoromethyl PFOS (P3MPFOS, P4MPFOS, and P5MPFOS), for which values of BF were 0.58 ± 0.07, 0.62 ± 0.06, and 0.61 ± 0.05 (day 6), respectively; these values are 5.8-, 7.8-, and 6.4-fold greater than those of technical PFOS. This work provides evidence on the isomer-specific accumulation of PFOS from diSPAP and will be helpful to track indirect sources of PFOS in the future.

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

    SciTech Connect

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

    2012-12-14

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

  11. Effect of oil sands process-affected water on toxicity of retene to early life-stages of Japanese medaka (Oryzias latipes).

    PubMed

    Alharbi, Hattan A; Morandi, Garrett; Giesy, John P; Wiseman, Steve B

    2016-07-01

    Toxicity of oil sands process-affected water (OSPW) to aquatic organisms has been studied, but effects of co-exposure to OSPW and polycyclic-aromatic hydrocarbons (PAHs), which are an important class of chemicals in tailings ponds used to store OSPW, has not been investigated. The goal of the current study was to determine if organic compounds extracted from the aqueous phase of relatively fresh OSPW from Base-Mine Lake (BML-OSPW) or aged OSPW from Pond 9 experimental reclamation pond (P9-OSPW) modulated toxic potency of the model alkyl-PAH, retene, to early life-stages of Japanese medaka (Oryzias latipes). Embryos were exposed to retene by use of a partition controlled delivery (PCD) system made of polydimethylsiloxane (PDMS) until day of hatch. Incidences of pericardial edema and expression of CYP1A were not significantly greater in larvae exposed only to dissolved organic compounds from either OSPW but were significantly greater in larvae exposed only to retene. Expression of CYP1A and incidences of pericardial edema were significantly greater in larvae co-exposed to retene and 5×equivalent of dissolved organic compounds from BML-OSPW compared to retene alone. However, there was no effect of co-exposure to retene and either a 1×equivalent of dissolved organic compounds from BML-OSPW or 5×equivalent of dissolved organic compounds from P9-OSPW. While there was evidence that exposure to 5×equivalent of dissolved organic compounds from BML-OSPW caused oxidative stress, there was no evidence of this effect in larvae exposed only to retene or co-exposed to retene and a 5×equivalent of dissolved organic compounds from BML-OSPW. These results suggest that oxidative stress is not a mechanism of pericardial edema in early-life stages of Japanese medaka. Relatively fresh OSPW from Base Mine Lake might influence toxicity of alkylated-PAHs to early life stages of fishes but this effect would not be expected to occur at current concentrations of OSPW and is attenuated by

  12. Effect of chronic exposure to two components of Tritan copolyester on Daphnia magna, Moina macrocopa, and Oryzias latipes, and potential mechanisms of endocrine disruption using H295R cells.

    PubMed

    Jang, Sol; Ji, Kyunghee

    2015-11-01

    Tritan copolyester is a novel plastic form from Eastman Company utilizing three main monomers, 1,4-cyclohexanedimethanol (CHDM), dimethyl terephthalate (DMT), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Despite Tritan has been widely applied for plastic bottles, the effects of long-term exposure to these compounds have seldom been investigated. We investigated chronic effects and endocrine disruption potential of CHDM and terephthalic acid (TPA), main mammalian metabolite formed from DMT, using crustacean Daphnia magna and Moina macrocopa, and freshwater fish (Oryzias latipes). The effects on sex hormone balance and the associated mechanisms were also investigated by use of H295R cells. In chronic toxicity test, D. magna showed significant decrease in reproduction (number of young per female) after exposure to 10 mg/L TPA. In early life stage exposure using O. latipes, significant decrease of juvenile survival and weight were observed in fish exposed to 10 mg/L and ≥1 mg/L CHDM, respectively. Expressions of vtg2 mRNA in fish exposed to CHDM and those of cyp19b, star, cyp17, and cyp19a mRNAs in fish exposed to TPA were significantly up-regulated. The results of H295R cell assay also showed that both chemicals at high concentrations could alter sex hormone production in steroidogenic pathway. The effective concentrations of the tested compounds were several orders of magnitude greater than the concentrations can be detected in ambient waters. Further in vivo and in vitro studies will be needed to investigate the effect of co-polymer on endocrine disruption. PMID:26289545

  13. Toxicity to early life stages and an estrogenic effect of a bisphenol A metabolite, 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene on the medaka (Oryzias latipes).

    PubMed

    Ishibashi, Hiroshi; Watanabe, Naoko; Matsumura, Naomi; Hirano, Masashi; Nagao, Yukiko; Shiratsuchi, Hideki; Kohra, Shinya; Yoshihara, Shin-Ichi; Arizono, Koji

    2005-10-01

    In a recent study, it was reported that 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), a metabolite of bisphenol A (BPA; 2,2-bis(4-hydroxyphenyl)propane), showed estrogenic activity in several in vitro assays, and the estrogenic activity of MBP was higher than that of BPA. In this study, we have investigated the early life stage toxicity and estrogenic effect of MBP on medaka (Oryzias latipes). The 96-h median lethal concentration value of MBP and BPA with 24-h-old larvae was estimated to be 1,640 and 13,900 microg/l, respectively. The hatchability of fertilized eggs exposed to MBP and BPA over 14 days was significantly decreased at doses of 2,500 microg/l and 12,500 microg/l, respectively. Moreover, to compare the potency of estrogenic activity in vivo, male medaka were exposed to various concentrations of MBP and BPA for 21 days. The lowest-observed-effect concentrations of MBP and BPA for hepatic vitellogenin induction in male medaka were estimated to be 4.1 and 1,000 microg/l, respectively. These results suggest that MBP has high toxicity for early life stages of the medaka, and that the estrogenic activity of MBP was about 250-fold higher than that of BPA to male medaka.

  14. Silver toxicity across salinity gradients: the role of dissolved silver chloride species (AgCl x ) in Atlantic killifish (Fundulus heteroclitus) and medaka (Oryzias latipes) early life-stage toxicity.

    PubMed

    Matson, Cole W; Bone, Audrey J; Auffan, Mélanie; Lindberg, T Ty; Arnold, Mariah C; Hsu-Kim, Heileen; Wiesner, Mark R; Di Giulio, Richard T

    2016-08-01

    The influence of salinity on Ag toxicity was investigated in Atlantic killifish (Fundulus heteroclitus) early life-stages. Embryo mortality was significantly reduced as salinity increased and Ag(+) was converted to AgCl(solid). However, as salinity continued to rise (>5 ‰), toxicity increased to a level at least as high as observed for Ag(+) in deionized water. Rather than correlating with Ag(+), Fundulus embryo toxicity was better explained (R(2) = 0.96) by total dissolved Ag (Ag(+), AgCl2 (-), AgCl3 (2-), AgCl4 (3-)). Complementary experiments were conducted with medaka (Oryzias latipes) embryos to determine if this pattern was consistent among evolutionarily divergent euryhaline species. Contrary to Fundulus data, medaka toxicity data were best explained by Ag(+) concentrations (R(2) = 0.94), suggesting that differing ionoregulatory physiology may drive observed differences. Fundulus larvae were also tested, and toxicity did increase at higher salinities, but did not track predicted silver speciation. Alternatively, toxicity began to increase only at salinities above the isosmotic point, suggesting that shifts in osmoregulatory strategy at higher salinities might be an important factor. Na(+) dysregulation was confirmed as the mechanism of toxicity in Ag-exposed Fundulus larvae at both low and high salinities. While Ag uptake was highest at low salinities for both Fundulus embryos and larvae, uptake was not predictive of toxicity. PMID:27170044

  15. Synergistic effect of high charge and energy particle radiation and chronological age on biomarkers of oxidative stress and tissue degeneration: a ground-based study using the vertebrate laboratory model organism Oryzias latipes.

    PubMed

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R; Weinberger, Paul M; Dynan, William S

    2014-01-01

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration. PMID:25375139

  16. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    PubMed Central

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-01-01

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration. PMID:25375139

  17. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    SciTech Connect

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZE particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.

  18. Ethanol induced attenuation of oxidative stress is unable to alter mRNA expression pattern of catalase, glutathione reductase, glutathione-S- transferase (GST1A), and superoxide dismutase (SOD3) enzymes in Japanese rice fish (Oryzias latipes) embryogenesis

    PubMed Central

    Wu, Minghui; Shariat-Madar, Bahbak; Haron, Mona H.; Wu, Mengmeng; Khan, Ikhlas A.; Dasmahapatra, Asok K.

    2010-01-01

    Although the mechanism of ethanol toxicity during embryogenesis is unknown, our earlier studies on Japanese rice fish (Oryzias latipes) embryos indicated that the effects might be mediated through oxidative stress. In this study we have determined the oxidative stress and the mRNA content of four antioxidant enzymes (catalase, glutathione reductase, glutathione-S-transferase, and superoxide dismutase) during Japanese rice fish embryogenesis (from 0 day post-fertilization to hatching) and after exposing the embryos to ethanol (100 and 300 mM) for 48 h at three stages (0–2, 1–3 and 4–6 day post fertilization, dpf) of organogenesis. We observed that oxidative stress was minimal in blastula, gastrula or neurula stages, increased gradually with the advancement of morphogenesis and reached its maximum level in hatchlings. The antioxidant enzyme mRNAs were constitutively expressed throughout development; however, the expression pattern was not identical among the enzymes. Catalase and superoxide dismutase (SOD) mRNAs were minimal in the fertilized eggs, but increased significantly in 1 dpf and then either sharply dropped (SOD) or maintained a steady-state (catalase). Glutathione S-transferase (GST) was very high in fertilized eggs and sharply dropped 1 dpf and then gradually increased thereafter. Glutathione reductase (GR) maintained a steady-state throughout the development. Ethanol was able to attenuate oxidative stress in embryos exposed only to 300 mM 1–3 dpf; no significant difference with controls was observed in other ethanol-treated groups. The antioxidant enzyme mRNAs also remained unaltered after ethanol treatment. From these data we conclude that the attenuation of oxidative stress by ethanol is probably due to the inhibition of normal growth of the embryos rather than by inhibiting catalase, GST, GR or SOD- dependent activities. PMID:20965276

  19. Gene-specific disruption of endocannabinoid receptor 1 (cnr1a) by ethanol probably leads to the development of fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish (Oryzias latipes) embryogenesis.

    PubMed

    Dasmahapatra, Asok K; Khan, Ikhlas A

    2015-01-01

    The present study was designed to investigate the probable roles played by cannabinoid (CB) receptors in fetal alcohol spectrum disorder (FASD) induction in Japanese rice fish (Oryzias latipes). Searching of public databases (GenBank, Ensembl) indicated that the Japanese rice fish genome includes three human ortholog CB receptor genes (cnr1a, cnr1b and cnr2). Quantitative real-time PCR (qPCR) and whole mount in situ hybridization (WMISH) techniques were used to analyze the expression of these cnr genes during Japanese rice fish embryogenesis and also in response to developmental ethanol exposure. qPCR analyses showed that the expression of all three CB receptor genes were developmentally regulated and only cnr2 showed maternal expression. The mRNA concentrations of these genes were found to be enhanced after 3 dpf and attained maximal levels either prior to or after hatching. WMISH technique indicated that all three cnr genes were expressed in the head region of hatchlings. During development, ethanol selectively attenuated the expression of cnr1a mRNA only. Blocking of cnr1a mRNA by CB1 receptor antagonists rimonabant (10-20 μM) or AM251 (0.2-1 μM) 0-2 dpf were unable to induce any FASD-related phenotypic features in embryos or in hatchlings. However, continuous exposure of the embryos (0-6 dpf) to AM251 (1 μM) was able to reduce the hatching efficiency of the embryos. Our data indicated that in Japanese rice fish, ethanol disrupted the expression of only cnr1a in a concentration-dependent manner that induced delay in hatching and might be responsible for the development of FASD phenotypes.

  20. Synergistic Effect of High Charge and Energy Particle Radiation and Chronological Age on Biomarkers of Oxidative Stress and Tissue Degeneration: A Ground-Based Study Using the Vertebrate Laboratory Model Organism Oryzias latipes

    DOE PAGES

    Zheng, Xuan; Zhang, Xinyan; Ding, Lingling; Lee, Jeffrey R.; Weinberger, Paul M.; Dynan, William S.

    2014-11-06

    High charge and energy (HZE) particles are a main hazard of the space radiation environment. Uncertainty regarding their health effects is a limiting factor in the design of human exploration-class space missions, that is, missions beyond low earth orbit. Previous work has shown that HZE exposure increases cancer risk and elicits other aging-like phenomena in animal models. Here, we investigate how a single exposure to HZE particle radiation, early in life, influences the subsequent age-dependent evolution of oxidative stress and appearance of degenerative tissue changes. Embryos of the laboratory model organism, Oryzias latipes (Japanese medaka fish), were exposed to HZEmore » particle radiation at doses overlapping the range of anticipated human exposure. A separate cohort was exposed to reference γ-radiation. Survival was monitored for 750 days, well beyond the median lifespan. The population was also sampled at intervals and liver tissue was subjected to histological and molecular analysis. HZE particle radiation dose and aging contributed synergistically to accumulation of lipid peroxidation products, which are a marker of chronic oxidative stress. This was mirrored by a decline in PPARGC1A mRNA, which encodes a transcriptional co-activator required for expression of oxidative stress defense genes and for mitochondrial maintenance. Consistent with chronic oxidative stress, mitochondria had an elongated and enlarged ultrastructure. Livers also had distinctive, cystic lesions. Depending on the endpoint, effects of γ-rays in the same dose range were either lesser or not detected. Results provide a quantitative and qualitative framework for understanding relative contributions of HZE particle radiation exposure and aging to chronic oxidative stress and tissue degeneration.« less

  1. In Vivo Monitoring of the Growth of Fertilized Eggs of Medaka Fish (Oryzias latipes) by Near-Infrared Spectroscopy and Near-Infrared Imaging-A Marked Change in the Relative Content of Weakly Hydrogen-Bonded Water in Egg Yolk Just before Hatching.

    PubMed

    Ishigaki, Mika; Yasui, Yui; Puangchit, Paralee; Kawasaki, Shoya; Ozaki, Yukihiro

    2016-08-01

    The present study develops further our previous study of in vivo monitoring at the molecular level of the embryonic development in Japanese medaka fish (Oryzias latipes) using near-infrared (NIR) spectroscopy and NIR imaging. NIR spectra were measured nondestructively for three major parts of fertilized medaka eggs (the embryonic body, oil droplets, and egg yolk) from the first day after fertilization to the day just before hatching (JBH). Changes in the contents of chemical components such as proteins, water, and lipids were monitored in situ during embryonic development. A marked change in the relative content of weakly hydrogen-bonded water was observed in the egg yolk JBH. Principal component analysis (PCA) was carried out using the NIR spectra data of the egg yolk and embryo on the fifth day after fertilization. The PCA clearly separates the egg yolk data from the embryo body parts. Principal component PC1 and PC2 loading plots suggest that the hydrogen bonding structure of water in the egg yolk is considerably different to those of the other parts and the fraction of weakly hydrogen-bonded water in the egg yolk is smaller than that in the embryonic body. NIR images developed from the intensities of peaks of second derivative spectra owing to water and proteins show their different distribution patterns. Images of the ratio of strongly and weakly hydrogen-bonded water confirmed that oil droplets and embryonic body parts have higher and lower ratios, respectively, of strongly hydrogen-bonded water than do the other parts. The images developed from the intensity of the peaks at 4864 and 4616 cm(-1) related to the proteins indicated that the egg yolk contains a higher concentration of protein than do the other parts. The peaks at 5756 and 4530 cm(-1) caused by the protein secondary structures of α-helix and β-sheet showed the configuration of the egg cell membrane. The present study might lead to new understanding at the molecular level regarding the growth of

  2. In Vivo Monitoring of the Growth of Fertilized Eggs of Medaka Fish (Oryzias latipes) by Near-Infrared Spectroscopy and Near-Infrared Imaging-A Marked Change in the Relative Content of Weakly Hydrogen-Bonded Water in Egg Yolk Just before Hatching.

    PubMed

    Ishigaki, Mika; Yasui, Yui; Puangchit, Paralee; Kawasaki, Shoya; Ozaki, Yukihiro

    2016-01-01

    The present study develops further our previous study of in vivo monitoring at the molecular level of the embryonic development in Japanese medaka fish (Oryzias latipes) using near-infrared (NIR) spectroscopy and NIR imaging. NIR spectra were measured nondestructively for three major parts of fertilized medaka eggs (the embryonic body, oil droplets, and egg yolk) from the first day after fertilization to the day just before hatching (JBH). Changes in the contents of chemical components such as proteins, water, and lipids were monitored in situ during embryonic development. A marked change in the relative content of weakly hydrogen-bonded water was observed in the egg yolk JBH. Principal component analysis (PCA) was carried out using the NIR spectra data of the egg yolk and embryo on the fifth day after fertilization. The PCA clearly separates the egg yolk data from the embryo body parts. Principal component PC1 and PC2 loading plots suggest that the hydrogen bonding structure of water in the egg yolk is considerably different to those of the other parts and the fraction of weakly hydrogen-bonded water in the egg yolk is smaller than that in the embryonic body. NIR images developed from the intensities of peaks of second derivative spectra owing to water and proteins show their different distribution patterns. Images of the ratio of strongly and weakly hydrogen-bonded water confirmed that oil droplets and embryonic body parts have higher and lower ratios, respectively, of strongly hydrogen-bonded water than do the other parts. The images developed from the intensity of the peaks at 4864 and 4616 cm(-1) related to the proteins indicated that the egg yolk contains a higher concentration of protein than do the other parts. The peaks at 5756 and 4530 cm(-1) caused by the protein secondary structures of α-helix and β-sheet showed the configuration of the egg cell membrane. The present study might lead to new understanding at the molecular level regarding the growth of

  3. Comparative genomics of duplicate γ-glutamyl transferase genes in teleosts: medaka (Oryzias latipes), stickleback (Gasterosteus aculeatus), green spotted pufferfish (Tetraodon nigroviridis), fugu (Takifugu rubripes) and zebrafish (Danio rerio)

    PubMed Central

    LAW, Sheran Hiu Wan; REDELINGS, Benjamin David; KULLMAN, Seth William

    2011-01-01

    The availability of multiple teleost (bony fish) genomes is providing unprecedented opportunities to understand the diversity and function of gene duplication events using comparative genomics. Here we examine multiple paralogous genes of γ-glutamyl transferase (GGT) in several distantly related teleost species including medaka, stickleback, green spotted pufferfish, fugu and zebrafish. Through mining genome databases, we have identified multiple GGT orthologs. Duplicate (paralogous) GGT sequences for GGT1 (GGT1 a and b), GGTL1 (GGTL1 a and b) and GGTL3 (GGTL3 a and b) were identified for each species. Phylogenetic analysis suggests that GGTs are ancient proteins conserved across most metazoan phyla and those paralogous GGTs in teleosts likely arose from the serial 3R genome duplication events. A third GGTL1 gene (GGTL1c) was found in green spotted pufferfish; however this gene is not present in medaka, stickleback or fugu. Similarly, one or both paralogs of GGTL3 appear to have been lost in green spotted pufferfish, fugu and zebrafish. Syntenic relationships were highly maintained between duplicated teleost chromosomes, among teleosts and across ray-finned (Actinopterygii) and lobe-finned (Sarcopterygii) species. To assess subfunction partitioning, six medaka GGT genes were cloned and assessed for developmental and tissue specific expression. Based upon these data, we propose a modification of the “duplication-degeneration-complementation” (DDC) model of subfunction partitioning where quantitative differences rather than absolute differences in gene expression are observed between gene paralogs. Our results demonstrate that multiple GGT genes have been retained within teleost genomes. Questions remain however regarding the functional roles of multiple GGTs in these species. PMID:21898790

  4. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes)

    USGS Publications Warehouse

    Papoulias, Diana M.; Tillitt, Donald E.; Talyknia, Melaniya G.; Whyte, Jeffrey J.; Richter, Catherine A.

    2014-01-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus–pituitary–gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36–42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  5. Atrazine reduces reproduction in Japanese medaka (Oryzias latipes).

    PubMed

    Papoulias, Diana M; Tillitt, Donald E; Talykina, Melaniya G; Whyte, Jeffrey J; Richter, Catherine A

    2014-09-01

    Atrazine is an effective broadleaf herbicide and the second most heavily used herbicide in the United States. Effects along the hypothalamus-pituitary-gonad axis in a number of vertebrate taxa have been demonstrated. Seasonally elevated concentrations of atrazine in surface waters may adversely affect fishes, but only a few studies have examined reproductive effects of this chemical. The present study was designed to evaluate a population endpoint (egg production) in conjunction with histological (reproductive stage, gonad pathology) and biochemical (aromatase activity, sex hormone production) phenotypes associated with atrazine exposure in Japanese medaka. Adult virgin breeding groups of one male and four females were exposed to nominal concentrations of 0, 0.5, 5.0, and 50 μg/L (0, 2.3, 23.2, 231 nM) of atrazine in a flow-through diluter for 14 or 38 days. Total egg production was lower (36-42%) in all atrazine-exposed groups as compared to the controls. The decreases in cumulative egg production of atrazine-treated fish were significant by exposure day 24. Reductions in total egg production in atrazine treatment groups were most attributable to a reduced number of eggs ovulated by females in atrazine-treated tanks. Additionally, males exposed to atrazine had a greater number of abnormal germ cells. There was no effect of atrazine on gonadosomatic index, aromatase protein, or whole body 17 β-estradiol or testosterone. Our results suggest that atrazine reduces egg production through alteration of final maturation of oocytes. The reduced egg production observed in this study was very similar to our previously reported results for fathead minnow. This study provides further information with which to evaluate atrazine's risk to fish populations.

  6. Circadian variations in the liver metabolites of medaka (Oryzias latipes)

    PubMed Central

    Fujisawa, Koichi; Takami, Taro; Kimoto, Yoshitaka; Matsumoto, Toshihiko; Yamamoto, Naoki; Terai, Shuji; Sakaida, Isao

    2016-01-01

    Circadian rhythms are biological rhythms with a period of around 24 hours. In this study, we compared the metabolome of the liver of medaka during the day and night. To comprehensively analyze the circadian variations in the levels of metabolites in the liver, livers were isolated from Zeitgeber time (ZT)4 and ZT16, and the variations in metabolite levels were evaluated. Inosinemonophosphate (IMP) and uridinemonophosphate (UMP) were found to be increased at night, indicating that nucleotide synthesis is most active during the night. Furthermore, the levels of metabolites of the tricarboxylic acid cycle were also reduced at night. In addition, the levels of many amino acids were reduced during the night, suggesting that the amino acids had been degraded. Moreover, the citrulline/ornithine ratio, which is related to arginine consumption, was lower during the day than at night. This pattern suggests that the urea cycle is activated during the day, whereas large amounts of nitric oxide and citrulline may be produced from arginine via nitric oxide synthase during the night. The results of this metabolomic analysis may be useful in future fundamental research to provide insight into chronobiology as well as applied research on drug evaluations using medaka as a model species. PMID:26862003

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

    EPA Science Inventory

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

  8. Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes).

    PubMed

    Schultz, I R; Reed, S; Pratt, A; Skillman, A D

    2007-02-01

    Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400-500 nauplii in less than 5 min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorption with peak body levels occurring within 1-2 h, then rapidly declining with elimination half-life of 0.3-3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h. PMID:17188578

  9. EARLY LIFESTAGE EFFECTS OF PAH PHOTOACTIVATED TOXICITY IN MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    Two critical questions have yet to be sufficiently addressed for risk assessments of photoactived PAH toxicity to be completed. These include standrdized methods for quantifying the dose of activating radiation received by target organisms, and the potential for early lifestage e...

  10. Early Life Exposure to Ractopamine Causes Endocrine-Disrupting Effects in Japanese Medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Wang, Sisi; Lin, Xia; Tan, Hana; Fu, Zhengwei

    2016-02-01

    β-Agonists, which are used as human pharmaceuticals or feed additives, have been detected in aquatic environments. β-Agonists have also been proposed for use in aquaculture. However, there are limited data available regarding the adverse effects of β-agonists in aquatic organisms. In this study, ractopamine was selected as the representative β-agonist, and medaka embryos were exposed at concentrations ranging from 5 to 625 μg/L for 44 days. In contrast to what has been found in mammals, ractopamine caused no growth response in medaka. However, the transcriptional changes of genes related to the hypothalamic-pituitary-gonadal (HPG) axis, especially in females, suggested that β-agonists may have the potential to disrupt the endocrine system. Moreover, genes involved in anti-oxidative activity or detoxification were affected in a gender-specific manner. These findings, particularly the effects on the endocrine system of fish, will advance our understanding of the ecotoxicity of β-agonists.

  11. Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Schultz, Irv; Reed, Stacey M.; Pratt, Amanda V.; Skillman, Ann D.

    2007-02-01

    Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400–500 nauplii in less than 5min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorptionwith peak body levels occurringwithin 1–2 h, then rapidly declining with elimination half-life of 0.3–3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h.

  12. Toxic effects of bisphenol A on early life stages of Japanese medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Lin, Xia; Jin, Rong; Peng, Tao; Peng, Zuhua; Fu, Zhengwei

    2014-08-01

    The toxic effects of bisphenol A (BPA) in aquatic organisms have attracted global attention. However, few studies have investigated its effects at the gene transcription level. In this study, we measured the transcriptional response of a set of genes associated with the hypothalamic-pituitary-gonadal axis following BPA exposure during the early life stage of Japanese medaka. Transcription of vitellogenin genes was induced in both sexes, indicating estrogenic disruption. However, changes in transcription of the steroid hormone receptor gene and steroidogenesis-regulating genes suggest that BPA also acts as an androgen receptor antagonist. BPA exposure also decreased the hatchability of medaka embryos and increased the growth of female larvae. These pronounced gender-specific effects observed in this study demonstrate that it is important to identify the sex of fish in the early life stage.

  13. EFFECTS OF DIETARY EXPOSURE TO THE PYRETHROID PESTICIDE ESFENVALERATE ON MEDAKA (ORYZIAS LATIPES). (R826940)

    EPA Science Inventory

    Abstract

    The pyrethroid insecticide esfenvalerate is widely used on orchard crops throughout California. In the aquatic environment, this compound is likely to accumulate in sediments, food particles and benthic organisms due to its lipophilicity and environmental pers...

  14. Toxicity of 17 {beta}-estradiol and dibutyl-n-phthalate to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Patvna, P.J.; Cooper, K.R. |

    1995-12-31

    Phthalate esters are ubiquitous environmental contaminants that are hypothesized to cause developmental toxicity in aquatic organisms via an estrogenic mechanism. Japanese medaka embryos and larvae provide an excellent model for the study of toxicant effects on embryonic development. The following groups were examined (N = 10--20): a non-treatment control, a vehicle control, 17 {beta}-estradiol and Dibutyl-n-phthalate, in individual glass vials. The medaka embryos were treated beginning at the blastula stage, for ten days. At day 10, embryos were changed into fresh rearing solution. The embryos were observed daily, until three days post-hatching, for toxic developmental effects. Exposure to 17 {beta}-estradiol caused urinary bladder lesions at the lowest doses tested. At concentrations {le} 3 {micro}M/0.82 ppm, 17 {beta}-estradiol caused inhibition of swim bladder inflation, pericardial edema, and marked cachexia. Dibutyl-n-phthalate caused pronounced enlargement of the urinary bladder. No other gross lesions were observed. Both 17 {beta}-estradiol and Dibutyl-n-phthalate caused effects on the urinary tract which will be characterized at the light microscopic level. The lesions observed in the embryo medaka following Dibutyl-n-phthalate exposure were at or below water solubility and are in agreement with previously reported toxic levels.

  15. Medaka fish, Oryzias latipes, as a model for human obesity-related glomerulopathy.

    PubMed

    Ichimura, Koichiro; Kawashima, Yusuke; Nakamura, Tomomi; Powell, Rebecca; Hidoh, Yuya; Terai, Shuji; Sakaida, Isao; Kodera, Yoshio; Tsuji, Takashi; Ma, Jian-Xing; Sakai, Tatsuo; Matsumoto, Hiroyuki; Obara, Tomoko

    2013-02-22

    Obesity, an ongoing significant public health problem, is a part of complex disease characterized as metabolic syndrome. Medaka and zebrafish are useful aquatic experimental animals widely used in the field of toxicology and environmental health sciences and as a human disease models. In medaka, simple feeding of a high fat diet (HFD) can induce body weight gain, excessive accumulation of visceral adipose tissue, hyperglycemia, hyperlipidemia, and steatohepatitis, which mimics human metabolic syndrome. In the present study, to explore the possibility that the adult medaka fed with HFD (HFD-medaka) can be used as an animal model for human metabolic syndrome-associated glomerular disease, including obesity-related glomerulopathy (ORG), we analyzed structural alterations and protein expression in the mesonephric kidney of HFD-medaka. We found that the histopathology was consistent with glomerulomegaly accompanied by the dilation of glomerular capillaries and proliferative expansion of the mesangium, a condition partially comparable to human ORG. Moreover, expressions of several kinds of kidney disease-related proteins (such as MYH9, SM22α) were significantly elevated. Thus, the HFD-medaka has a high potential as an animal model useful for exploring the mechanism underling human ORG.

  16. The chronic effects of lignin-derived bisphenol and bisphenol A in Japanese medaka Oryzias latipes.

    PubMed

    Li, Dan; Chen, Qin; Cao, Jinling; Chen, Hongxing; Li, Lixia; Cedergreen, Nina; Xie, Haibo; Xie, Lingtian

    2016-01-01

    One of the ultimate goals of green chemistry is to produce greener and more environmentally friendly chemicals to replace the existing toxic chemicals. In this study, Japanese medaka were exposed to 1.5mg/L of bisphenol A or lignin-derived bisphenol for 60 days, and the expressions of various biochemical markers, effects on reproduction, and histopathology were evaluated. The results showed that concentrations of liver vitellogenin of LD-BP exposed males were approximately 125% higher compared to the control males. Total number of eggs from the BPA and LD-BP exposed fish was approximately 47% (p<0.001) and 25% (p<0.05) less than the control fish, respectively. Total number of brood was lower from the BPA (46%, p<0.05) and LD-BP (17%, p<0.05) exposed fish than that of the control fish. Relative to the control fish, catalase and glutathione-S-transferase were significantly affected by the two chemicals in all tested tissues. BPA and LD-BP caused lipid peroxidation in all the tested tissues. Furthermore, acetylcholinesterase and α-glucosidase activity were significantly inhibited. Histopathological analysis showed that both the testis and ovary were mildly damaged by both chemicals. LD-BP affected medaka slightly more severe than BPA except on the reproduction, which was most likely due to different uptake, translocation, binding to targets and metabolism. Our results demonstrated that chronic exposure to both chemicals caused several adverse effects to medaka. Further research on the toxicity of LD-BP to other aquatic organisms is needed before substitution of traditional BPA with LD-BP can be recommended. PMID:26674368

  17. Development of the pancreas in medaka, Oryzias latipes, from embryo to adult.

    PubMed

    Otsuka, Takayoshi; Tsukahara, Tatsuya; Takeda, Hiroyuki

    2015-10-01

    To address conserved and unique features of fish pancreas development, we performed extensive analyses of pancreatic development in medaka embryos and adults using pdx1- and ptf1a-transgenic medaka, in situ hybridization and immunohistochemistry. The markers used in these analyses included pdx1, nkx6.1, nkx6.2, nkx2.2, Islet1, insulin, Somatostatin, glucagon, ptf1a, ela3l, trypsin, and amylase. The double transgenic (Tg) fish produced in the present study visualizes the development of endocrine (pdx1+) and exocrine (ptf1a+) parts simultaneously in living fishes. Like other vertebrates, the medaka pancreas develops as two (dorsal and ventral) buds in the anterior gut tube, which soon fuse into a single anlagen. The double Tg fish demonstrates that the differential property between the two buds is already established at the initial phase of bud development as indicated by strong pdx1 expression in the dorsal one. This Tg fish also allowed us to examine the gross morphology and the structure of adult pancreas and revealed unique characters of medaka pancreas such as broad and multiple connections with the gut tube along the anterior-posterior axis.

  18. Effects of Silver Nanoparticles on Japanese Medaka (Oryzias latipes) and Daphnia magna

    EPA Science Inventory

    The introduction of nanoparticles into a variety of consumer products has raised questions about the potential effects of environmental release, and particularly whether the presence of materials at the nano-scale creates potential risks not associated with the bulk materials. C...

  19. 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...

  20. Mechanistic studies of pericardial edema in early life stages (ELS) of medaka (Oryzias latipes)

    SciTech Connect

    Villalobos, S.A.; Fan, T.W.M.; Higashi, R.M.; Hinton, D.E.

    1995-12-31

    Pericardial edema (PE), a manifestation of developmental toxicity in fish ELS, may compromise stock recruitment and survival. However, the mechanism underlying this common lesion is unknown. Possible mechanisms for PE in ELS of medaka were studied by metabolic and morphologic methods. In the laboratory, medaka embryos readily develop PE after brief exposure to dioxin, trichloroethylene (TCE) soot extract, or thiobencarb. Histopathological analyses, regardless of agent, indicated widespread edema without cellular infiltrates in pericardial and peritoneal cavities and in subepithelial spaces of skin. Additionally, endothelia of sinus venosus and adjacent atrium were enlarged. Walls of dilated sinoatrial compartments showed subendothelial fluid accumulation. Ethoxyresorufin O-deethylase activity (indicator of CYPL A induction), considerably higher in embryos exposed to dioxin and TCE soot, was suppressed by thiobencarb. In vivo {sup 31}P nuclear magnetic resonance (NMR) spectroscopy of living embryos (pregastrula through hatching) previously treated with thiobencarb, showed a temporary depression of ATP and phosphocreatine levels, with an apparent transient alkalinization in intracellular (possibly yolk sac) pH. Results indicate that induction of CYP1A is not a requirement for development of PE, and that ionic imbalances and/or metabolic disorders following exposure may be causative factor(s).

  1. The chronic effects of lignin-derived bisphenol and bisphenol A in Japanese medaka Oryzias latipes.

    PubMed

    Li, Dan; Chen, Qin; Cao, Jinling; Chen, Hongxing; Li, Lixia; Cedergreen, Nina; Xie, Haibo; Xie, Lingtian

    2016-01-01

    One of the ultimate goals of green chemistry is to produce greener and more environmentally friendly chemicals to replace the existing toxic chemicals. In this study, Japanese medaka were exposed to 1.5mg/L of bisphenol A or lignin-derived bisphenol for 60 days, and the expressions of various biochemical markers, effects on reproduction, and histopathology were evaluated. The results showed that concentrations of liver vitellogenin of LD-BP exposed males were approximately 125% higher compared to the control males. Total number of eggs from the BPA and LD-BP exposed fish was approximately 47% (p<0.001) and 25% (p<0.05) less than the control fish, respectively. Total number of brood was lower from the BPA (46%, p<0.05) and LD-BP (17%, p<0.05) exposed fish than that of the control fish. Relative to the control fish, catalase and glutathione-S-transferase were significantly affected by the two chemicals in all tested tissues. BPA and LD-BP caused lipid peroxidation in all the tested tissues. Furthermore, acetylcholinesterase and α-glucosidase activity were significantly inhibited. Histopathological analysis showed that both the testis and ovary were mildly damaged by both chemicals. LD-BP affected medaka slightly more severe than BPA except on the reproduction, which was most likely due to different uptake, translocation, binding to targets and metabolism. Our results demonstrated that chronic exposure to both chemicals caused several adverse effects to medaka. Further research on the toxicity of LD-BP to other aquatic organisms is needed before substitution of traditional BPA with LD-BP can be recommended.

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

    PubMed

    Dasmahapatra, Asok K; Khan, Ikhlas A

    2015-01-01

    We aimed to investigate the impact of the epigenome in inducting fetal alcohol spectrum disorder (FASD) phenotypes in Japanese rice fish embryogenesis. One of the significant events in epigenome is DNA methylation which is catalyzed by DNA methyltransferase (DNMT) enzymes. We analyzed DNMT enzyme mRNA expressions in Japanese rice fish development starting from fertilized eggs to hatching and also in embryos exposed for first 48h of development either to ethanol (300mM) or to 5-azacytidine (5-azaC; 2mM), an inhibitor of DNMT enzyme activity. As observed in FASD phenotypes, 5-azaC exposure was able to induce microcephaly and craniofacial cartilage deformities in Japanese rice fish. Moreover, we have observed that expression of DNMTs (dnmt1, dnmt3aa, and dnmt3bb.1) are developmentally regulated; high mRNA copies were found in early stages (1-2day-post-fertilization, dpf), followed by gradual reduction until hatched. In ethanol-treated embryos, compared to controls, dnmt1 mRNA is in reduced level in 2dpf and in enhanced level in 6dpf embryos. While dnmt3aa and 3bb.1 remained unaltered. In contrast, embryos exposed to 5-azaC have an enhanced level of dnmt1 and dnmt3bb.1 mRNAs both in 2 and 6dpf embryos while dnmt3aa is enhanced only in 6dpf embryos. Moreover, endocannabinoid receptor 1a (cnr1a) mRNA which was found to be reduced by ethanol remained unaltered and cnr1b and cnr2 mRNAs, which were remained unaltered by ethanol, were increased significantly by 5-azaC in 6dpf embryos. This study indicates that the craniofacial defects observed in FASD phenotypes are the results of dysregulations in DNMT expressions.

  3. Accumulation and effects of Cr(VI) in Japanese medaka (Oryzias latipes) during chronic dissolved and dietary exposures.

    PubMed

    Chen, Hongxing; Mu, Lei; Cao, Jinling; Mu, Jingli; Klerks, Paul L; Luo, Yongju; Guo, Zhongbao; Xie, Lingtian

    2016-07-01

    Chromium (Cr) is an essential metal and a nutritional supplement for both human and agricultural uses. It is also a pollutant from a variety of industrial uses. These uses can lead to elevated Cr levels in aquatic environments, where it can enter and affect aquatic organisms. Its accumulation and subsequent effects in fish have received relatively little attention, especially for chronic exposure. In the present study, Japanese medaka were chronically exposed to dissolved or dietary Cr(VI) for 3 months. Cr accumulation in liver, gills, intestine, and brain was evaluated. Effects on the antioxidant system, nervous system (acetylcholinesterase, AChE), digestive system (α-glucosidase, α-Glu), and tissue histology (liver and gills) were also assessed. Cr accumulation was observed in the intestine and liver of fish exposed to Cr-contaminated brine shrimp. However, chronic dissolved Cr exposure led to significant Cr accumulation in all organs tested. Analysis of the subcellular distribution of Cr in medaka livers revealed that 37% of the Cr was present in the heat stable protein fraction. The dissolved Cr exposure had pronounced effects on the antioxidant system in the liver, with an elevated ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and decreases in GSH and glutathione S-transferase (GST). The α-Glu activity in the intestine was significantly inhibited. In addition, Cr exposure caused histopathological alterations in the gills and liver. In general, the effects of dietary Cr were relatively minor, possible due to the much lower accumulation in the fish. Our results imply that Japanese medaka accumulate Cr mainly via uptake of dissolved Cr(VI).

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

    PubMed Central

    Papoulias, Diana M; Villalobos, Sergio A; Meadows, John; Noltie, Douglas B; Giesy, John P; Tillitt, Donald E

    2003-01-01

    Despite being banned in many countries, dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) continue to be found in fish tissues at concentrations of concern. Like o,p -DDT, o,p -DDE is estrogenic and is believed to exert its effects through binding to the estrogen receptor. The limited toxicologic data for o,p -DDE suggest that it decreases fecundity and fertility of fishes. We conducted an egg injection study using the d-rR strain of medaka and environmentally relevant concentrations of o,p -DDE to examine its effects on sexual differentiation and development. The gonads of exposed fish showed no evidence of sex reversal or intersex. However, other gonad abnormalities occurred in exposed individuals. Females exhibited few vitellogenic oocytes and increased atresia. Male testes appeared morphologically normal but were very small. Gonadosomatic index values for both sexes were lower for exposed fish. Our observations of abnormal female and very small male gonads after in ovo o,p -DDE exposure may be indicative of effects on early endocrine processes important for normal ovarian and testicular development. PMID:12515675

  5. P-NITROPHENOL AND GLUTATHIONE RESPONSE IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO MX, A DRINKING WATER CARCINOGEN.

    EPA Science Inventory

    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 cytochr...

  6. Transcriptional responses in the brain, liver and gonad of Japanese ricefish (Oryzias latipes) exposed to two anti-estrogens.

    PubMed

    Sun, Liwei; Shao, Xiaolu; Chi, Jian; Hu, Xinhua; Jin, Yuanxiang; Fu, Zhengwei

    2011-05-01

    The study of endocrine disruption is being increasingly conducted at the mRNA level of genes, as this approach might yield insight into the modes of action and mechanisms of toxicity. In this study, the transcriptional responses of a set of functionally relevant genes associated with the pathways of the hypothalamic-pituitary-gonadal (HPG; or HPG[L]-liver) axis of Japanese ricefish were examined after treatment with two model anti-estrogens, letrozole (LET) and tamoxifen (TAM), at three concentrations (30, 100 and 300μg/L) for 72h. The results showed that LET and TAM produced distinct expression profiles in a complex tissue- and gender-specific manner, confirming that they exert their anti-estrogenic effects via different molecular mechanisms. For example, the transcriptional levels of hepatic vitellogenin were significantly downregulated in females exposed to either LET or TAM, while they were significantly upregulated in TAM-exposed males and did not exhibit any change in LET-treated males. The expression of genes involved in steroidogenesis was also modulated by these two anti-estrogens in a way that corresponded with their anticipated mode of action. Overall, the data not only provide mechanistic information of anti-estrogenic chemicals but also demonstrate the potential of investigation of gene expression in the HPG(L) axis of model fish for diagnostic and predictive assessments of the risks associated with chemical exposure.

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

    USGS Publications Warehouse

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

    2015-01-01

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

  8. PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES

    EPA Science Inventory

    The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

  9. Effects of trilostane and fipronil on the reproductive axis in an early life stage of the Japanese medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Jin, Rong; Peng, Zuhua; Zhou, Qiwei; Qian, Haifeng; Fu, Zhengwei

    2014-08-01

    Given the critical role of the hypothalamic-pituitary-gonadal (HPG) axis, it is conceivable that perturbations at any point along this axis can potentially affect reproduction in fish and other vertebrates. We investigated the effects of a 3β-hydroxysteroid dehydrogenase (3β-HSD) inhibitor, trilostane (TRI), and a gamma-aminobutyric acid (GABA)-receptor antagonist, fipronil (FIP), on the HPG axis using an early life stage of the Japanese medaka. The newly hatched larvae were exposed to TRI (100, 300 and 1000 μg/L) and FIP (3, 10 and 30 μg/L), respectively, until 28 days post-hatching. Exposure to TRI decreased the body length in males, whereas FIP inhibited growth in both sexes. The induction of steroidogenesis-regulating genes (including 3β-hsd) in males exposed to TRI, accompanied by increased vtg and er transcription, indicating a compensatory response to the presumed 3β-HSD inhibition. These compensatory responses were not observed in TRI-treated females. Regarding FIP exposure, the GABA blocker resulted in the down-regulation of fshr and lhr. A compensatory up-regulation of steroidogenesis-regulating genes partially explained the elevated transcripts of vtg genes in both males and females after FIP exposure. These results suggest that both the inhibition of 3β-HSD and the antagonism of GABA receptors are relevant modes of endocrine disruption that could impact the normal regulation of the HPG axis.

  10. Dmy initiates masculinity by altering Gsdf/Sox9a2/Rspo1 expression in medaka (Oryzias latipes)

    PubMed Central

    Chakraborty, Tapas; Zhou, Lin Yan; Chaudhari, Aparna; Iguchi, Taisen; Nagahama, Y.

    2016-01-01

    Despite identification of several sex-determining genes in non-mammalian vertebrates, their detailed molecular cascades of sex determination/differentiation are not known. Here, we used a novel RNAi to characterise the molecular mechanism of Dmy (the sex-determining gene of medaka)-mediated masculinity in XY fish. Dmy knockdown (Dmy-KD) suppressed male pathway (Gsdf, Sox9a2, etc.) and favoured female cascade (Rspo1, etc.) in embryonic XY gonads, resulting in a fertile male-to-female sex-reversal. Gsdf, Sox9a2, and Rspo1 directly interacted with Dmy, and co-injection of Gsdf and Sox9a2 re-established masculinity in XY-Dmy-KD transgenics, insinuating that Dmy initiates masculinity by stimulating and suppressing Gsdf/Sox9a2 and Rspo1 expression, respectively. Gonadal expression of Wt1a starts prior to Dmy and didn’t change upon Dmy-KD. Furthermore, Wt1a stimulated the promoter activity of Dmy, suggesting Wt1a as a regulator of Dmy. These findings provide new insights into the role of vertebrate sex-determining genes associated with the molecular interplay between the male and female pathways. PMID:26806354

  11. Effects of Madagascar yam extracts, Dioscorea antaly, on embryo-larval development of medaka fish, Oryzias latipes.

    PubMed

    Rakotobe, Lolona; Berkal, Miassa; Huet, Hélène; Djediat, Chakib; Jeannoda, Victor; Bodo, Bernard; Mambu, Lengo; Crespeau, François; Edery, Marc

    2010-01-01

    The yams edible starchy tubers, are of cultural, economic and nutritional importance in tropical and subtropical regions. The present study concerns the analysis at different levels of Dioscorea antaly toxicity to medaka embryo-larval development. The incubation of medaka fish embryos in a medium containing Dioscorea antaly extract resulted in a dose dependent reduction in survival rate. Survival rates were reduced up to 100% with extract concentrations of 4mg mL(-1). The LD(50) was estimated to be 0.86mg mL(-1)Dioscorea antaly. Anatomopathological studies did not show any caustic effects, irritation to mouth, throat or intestinal tract in surviving embryos but rather an inflammatory reaction in the liver. The data presented in this paper thus extends the use of medaka embryos as a valuable model to analyze the effects of food toxins.

  12. Accumulation and effects of Cr(VI) in Japanese medaka (Oryzias latipes) during chronic dissolved and dietary exposures.

    PubMed

    Chen, Hongxing; Mu, Lei; Cao, Jinling; Mu, Jingli; Klerks, Paul L; Luo, Yongju; Guo, Zhongbao; Xie, Lingtian

    2016-07-01

    Chromium (Cr) is an essential metal and a nutritional supplement for both human and agricultural uses. It is also a pollutant from a variety of industrial uses. These uses can lead to elevated Cr levels in aquatic environments, where it can enter and affect aquatic organisms. Its accumulation and subsequent effects in fish have received relatively little attention, especially for chronic exposure. In the present study, Japanese medaka were chronically exposed to dissolved or dietary Cr(VI) for 3 months. Cr accumulation in liver, gills, intestine, and brain was evaluated. Effects on the antioxidant system, nervous system (acetylcholinesterase, AChE), digestive system (α-glucosidase, α-Glu), and tissue histology (liver and gills) were also assessed. Cr accumulation was observed in the intestine and liver of fish exposed to Cr-contaminated brine shrimp. However, chronic dissolved Cr exposure led to significant Cr accumulation in all organs tested. Analysis of the subcellular distribution of Cr in medaka livers revealed that 37% of the Cr was present in the heat stable protein fraction. The dissolved Cr exposure had pronounced effects on the antioxidant system in the liver, with an elevated ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and decreases in GSH and glutathione S-transferase (GST). The α-Glu activity in the intestine was significantly inhibited. In addition, Cr exposure caused histopathological alterations in the gills and liver. In general, the effects of dietary Cr were relatively minor, possible due to the much lower accumulation in the fish. Our results imply that Japanese medaka accumulate Cr mainly via uptake of dissolved Cr(VI). PMID:27162070

  13. A Trial to Cryopreserve Immature Medaka (Oryzias latipes) Oocytes after Enhancing Their Permeability by Exogenous Expression of Aquaporin 3

    PubMed Central

    VALDEZ JR, Delgado M.; TSUCHIYA, Ryoma; SEKI, Shinsuke; SAIDA, Naoya; NIIMI, Saori; KOSHIMOTO, Chihiro; MATSUKAWA, Kazutsugu; KASAI, Magosaburo; EDASHIGE, Keisuke

    2013-01-01

    Abstract Fish oocytes have not been cryopreserved successfully, probably because it is difficult to prevent intracellular ice from forming. Previously, we have shown in medaka that immature oocytes are more suitable for cryopreservation than mature oocytes or embryos, in terms of permeability. We have also shown in immature medaka oocytes that the exogenous expression of aquaporin 3 (AQP3), a water/cryoprotectant channel, promotes the movement of water and cryoprotectants through the plasma membrane. In the present study, we attempted to cryopreserve immature medaka oocytes expressing AQP3. We first examined effects of hypertonic stress and the chemical toxicity of cryoprotectants on the survival of the AQP3-expressing oocytes. Exposure to hypertonic solutions containing sucrose decreased the survival of oocytes, but the expression of AQP3 did not affect sensitivity to hypertonic stress. Also, AQP3 expression did not markedly increase sensitivity to the toxicity of cryoprotectants. Of the four cryoprotectants tested, propylene glycol was the least toxic. Using a propylene glycol-based solution, therefore, we tried to cryopreserve immature oocytes by vitrification. During cooling with liquid nitrogen, all intact oocytes became opaque, but many AQP3-expressing oocytes remained transparent. This indicates that the expression of AQP3 is effective in preventing intracellular ice from forming during cooling. During warming, however, all the AQP3-expressing oocytes became opaque, indicating that intracellular ice formed. Therefore, the dehydration and permeation by propylene glycol were still insufficient. Further studies are necessary to realize the cryopreservation of fish oocytes. PMID:23337101

  14. VISUALIZATION OF TISSUE DISTRIBUTION AND METABOLISM OF BENZO[A]PYRENE IN EARLY EMBRYONIC MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    Fish early life stages are highly sensitive to exposure to persistent bioaccumulative toxicants (PBTs). The factors that contribute to this are unknown, but may include the distribution of PBTs to sensitive tissues during critical stages of development. Multiphoton laser scannin...

  15. p-Nitrophenol and glutathione response in medaka (Oryzias latipes)exposed to MX, a drinking water carcinogen

    EPA Science Inventory

    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 ...

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

    PubMed

    Dasmahapatra, Asok K; Khan, Ikhlas A

    2016-01-01

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

  17. The Effect of Estradiol-17(beta), Goitrogen (T3), and Flutamide on Gene Expression in Medaka, Oryzias latipes

    SciTech Connect

    E.Haut, J

    2005-09-06

    Concern has been generated over the discovery of endocrine disrupting chemicals in rivers near sewage outflows. The presence of endocrine disrupting chemicals such as estradiol-17{beta} has been associated with a reduction of reproductive success in fish and an increase in the female phenotype and gonadal intersex in fish downstream of sewage treatment facilities. Such effects are believed to result from a disruption in the normal estrogenic pathways since estrogen plays a vital role in reproduction, sexual differentiation, the developments of secondary sex characteristics, and ovulation. Most studies have focused on the effect of a single endocrine disruptor on a single gene which does not provide for the interaction between genes. Microarray technology has made it possible to put an entire genome on a single chip so that researchers can get a clearer picture of the interaction of genes expressed in a cell and changes of said interactions when those cells are exposed to various conditions. Medaka males were exposed to known endocrine disruptors, estradial-17{beta} and goitrogen, and medaka females were exposed to flutamide. All treatments were then compared to controls. Total RNA was extracted from the livers of both treated and untreated males and hybridized to a microarray chip designed to have EST sequences specific to medaka. ESTs were identified through two-channel microarray analysis and compared to GenBank using blastn searches to identify up regulated genes. Choriogenins H and L, zona radiata, and vitellogenin, previously shown to be estrogen-induced in male fish were identified. Heat shock proteins (hsp70, hsp90, and hsp8) were also induced by estradiol-17{beta}, as was choriogenin Hminor. Exposure to goitrogen (T3) resulted in the induced expression of glutathione S-transferase and a GABA receptor protein in male medaka. Treatment with flutamide, an antiandrogen, caused the up regulation of choriogenin L, choriogenin Hminor, and zona radiata-2 in female medaka. Further study of the genes identified in this study may serve as possible biomarkers to signal the effects caused by the presence of endocrine disruptors and provide a screening mechanism for the presence of estrogens in the environment. Microarray technology may provide a means to screen multiple biomarkers simultaneously and provide a more rapid and accurate tool for assessing endocrine disruption due to environmental pollutants.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Toxicity test using medaka (Oryzias latipes) early fry and concentrated sample water as an index of aquatic habitat condition.

    PubMed

    Yamashita, H; Haribowo, R; Sekine, M; Oda, N; Kanno, A; Shimono, Y; Shitao, W; Higuchi, T; Imai, T; Yamamoto, K

    2011-08-01

    The aim of the present study was to show a relationship between toxicity of 100-fold concentrated water and aquatic habitat conditions. Environmental waters are 100-fold concentrated with solid-phase extraction. Medaka early fry was exposed in these waters for 48 h. The number of death and disorder was counted at 1, 2, 3, 6, 12, 24, and 48 h; toxicity was expressed using inverse median effect time and median lethal time (ET (50)(-1), LT (50)(-1)). Average score per taxon (ASPT) for benthic animals and Index of Biotic Integrity (IBI) for fish were applied as indices of aquatic habitat conditions. The results of toxicity test were compared using ASPT and IBI. The different levels of toxicity were detected in the seawater of Japan. At the Husino River area, toxicity cannot be detected. In rivers, high toxicity appeared at urban districts without sewerage. By Spearman coefficient, the relationship between toxicity and high biochemical oxygen demand (BOD) were obtained. BOD household wastewater contains hydrophobic toxic matters; otherwise, seawater in industrial area does not show clear relationship between toxicity and chemical oxygen demand. Gas chromatography to mass spectrometry simultaneous analysis database may give an answer for the source of toxicity, but further test is required. Ratio of clear stream benthic animal sharply decreased over 0.25 of LT (50)(-1) or 0.5 of ET (50)(-1). Tolerant fish becomes dominant over 0.3 of LT (50)(-1) or 0.5-1.0 of ET (50)(-1). By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and ASPT was obtained at -0.773 (ET (50)(-1)) and -0.742 (LT (50)(-1)) at 1 % level of significance with a high negative correlation. Toxicity (LT (50)(-1) ) has strong correlation with the ratio of tolerant species. By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and IBI obtained were -0.155 (ET (50)(-1)) and -0.190 (LT (50)(-1)) at 1 % level of significance and has a low or no correlation between toxicity and IBI. Even with low toxic environmental waters, toxicity test using 100-fold concentrated and medaka early fly could detect acute toxicity. The detected toxicity seemed to limit the inhabiting aquatic species in the water body. PMID:22828886

  1. INCREASING UPTAKE AND BIOACTIVATION WITH DEVELOPMENT POSITIVELY MODULATE DIAZINON TOXICITY IN EARLY LIFE STAGE MEDAKA (ORYZIAS LATIPES). (R825433)

    EPA Science Inventory

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

  2. ORGANOPHOSPHATE-INDUCED ACETYLCHOLINESTERASE INHIBITION AND EMBRYONIC RETINAL CELL NECROSIS IN VIVO IN THE TELEOST (ORYZIAS LATIPES). (R825433)

    EPA Science Inventory

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

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

    EPA Science Inventory

    Abstract

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

  4. Uptake of silver nanoparticles and toxicity to early life stages of Japanese medaka (Oryzias latipes): effect of coating materials.

    PubMed

    Kwok, Kevin W H; Auffan, Melanie; Badireddy, Appala R; Nelson, Clay M; Wiesner, Mark R; Chilkoti, Ashutosh; Liu, Jie; Marinakos, Stella M; Hinton, David E

    2012-09-15

    Silver nanoparticles (AgNPs) with antimicrobial properties are perhaps the most deployed engineered nanomaterials in consumer products. Almost all AgNPs are coated with organic materials to enhance their dispersion in water. Contributions of coatings to the toxicity of NPs have received little attention. Studies using AgNPs with one of three different coating materials (citrate (Cit), gum arabic (GA), and polyvinylpyrrolidone (PVP)) showed significantly different toxicity. GA AgNP proved to be the most toxic, while PVP and Cit AgNP exhibited similar and lower toxicity. However, all AgNPs were about three to ten times less toxic than AgNO(3) when their toxicities were compared on a mass-concentration basis. Evidence for NP-specific toxicity was observed with longer time for initiation of toxicity and increased incidence of resultant spinal flexure of medaka exposed to AgNPs, compared to AgNO(3). Hyperspectral imaging of 6 μm paraffin sections of fish exposed to AgNPs revealed AgNPs and their aggregates in tissues of fish. Gill distribution was ubiquitous, while small amounts were found in other organs, including the liver and brain. AgNPs were observed regularly in the gut lumen, but rarely in mural elements and mesentery. These results suggest that while ingestion was common, gills were the principal sites of AgNP uptake. In conclusion, AgNPs is a source of toxic Ag ions, while itself contribute partially to its toxicity to fish, and which interact with skin surface and were taken up via the gills.

  5. EFFECTS OF CADMIUM ON THE HYPOTHALAMUS-PITUITARY-GONADAL AXIS IN JAPANESE MEDAKA (ORYZIAS LATIPES): CONSEQUENCES FOR REPRODUCTION AND DEVELOPMENT

    EPA Science Inventory

    Cadmium (Cd) is an important inorganic pollutant that exists from both natural and anthropogenic emission. Concentrations measured in the aquatic environment vary considerably from 0.05 to 1,000 ppb depending on contamination, but even range in drinking water from 1 to 10 ppb. C...

  6. Dmy initiates masculinity by altering Gsdf/Sox9a2/Rspo1 expression in medaka (Oryzias latipes).

    PubMed

    Chakraborty, Tapas; Zhou, Lin Yan; Chaudhari, Aparna; Iguchi, Taisen; Nagahama, Y

    2016-01-01

    Despite identification of several sex-determining genes in non-mammalian vertebrates, their detailed molecular cascades of sex determination/differentiation are not known. Here, we used a novel RNAi to characterise the molecular mechanism of Dmy (the sex-determining gene of medaka)-mediated masculinity in XY fish. Dmy knockdown (Dmy-KD) suppressed male pathway (Gsdf, Sox9a2, etc.) and favoured female cascade (Rspo1, etc.) in embryonic XY gonads, resulting in a fertile male-to-female sex-reversal. Gsdf, Sox9a2, and Rspo1 directly interacted with Dmy, and co-injection of Gsdf and Sox9a2 re-established masculinity in XY-Dmy-KD transgenics, insinuating that Dmy initiates masculinity by stimulating and suppressing Gsdf/Sox9a2 and Rspo1 expression, respectively. Gonadal expression of Wt1a starts prior to Dmy and didn't change upon Dmy-KD. Furthermore, Wt1a stimulated the promoter activity of Dmy, suggesting Wt1a as a regulator of Dmy. These findings provide new insights into the role of vertebrate sex-determining genes associated with the molecular interplay between the male and female pathways. PMID:26806354

  7. Molecular and phenotypic responses of Japanese medaka (Oryzias latipes) early life stages to environmental concentrations of cadmium in sediment.

    PubMed

    Barjhoux, Iris; Gonzalez, Patrice; Baudrimont, Magalie; Cachot, Jérôme

    2016-09-01

    Japanese medaka embryos were exposed to environmental concentrations of cadmium (Cd) to investigate adverse and adaptive responses in fish early life stages. Embryos were exposed during their whole development by static sediment-contact to environmental Cd concentrations (2 and 20 μg/g dry weight). Cd bioaccumulation, developmental defects, biochemical and biomolecular (qRT-PCR) responses were analyzed in embryos and hatchlings. A dose-dependent increase of Cd bioaccumulation and developmental defects was observed at hatching. Cd had clear impacts on heartbeat and cardiac morphogenesis and also induced to spinal deformities. The profile and the level of gene transcription were differentially modulated according to the Cd concentration, the duration of exposure and/or the developmental stage of fish. Pro-apoptotic bax and DNA repair rad51 transcripts were significantly repressed in embryos exposed to the highest Cd concentration. Repression of these genes was correlated to the increase of heart rate in 6-day-old embryos. NADH-dehydrogenase nd5 gene transcription was inhibited in larvae at the lowest concentration suggesting mitochondrial respiratory chain impairment, in association with Cd-induced teratogenicity. Finally, wnt1 gene was overexpressed indicating putative deregulation of Wnt signaling pathway, and suggested to be implied in the occurrence of some spinal and cardiac deformities. Results of this study permitted to propose some promising markers at the transcriptional and phenotypical level, responding to environmental concentrations of Cd. The present work also highlights the usefulness of the modified version of the medaka embryo-larval assay with sediment-contact exposure (MELAc) to investigate the toxicity and the modes of action of sediment-bound pollutants. PMID:27255318

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

    USGS Publications Warehouse

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

    2003-01-01

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

  9. Effect of long real space flight on the whole genome mRNA expression properties in medaka Oryzias latipes

    NASA Astrophysics Data System (ADS)

    Kozlova, Olga; Gusev, Oleg; Levinskikh, Margarita; Sychev, Vladimir; Poddubko, Svetlana

    The current study is addressed to the complex analysis of whole genome mRNA expression profile and properties of splicing variants formation in different organs of medaka fish exposed to prolonged space flight in the frame of joint Russia-Japan research program “Aquarium-AQH”. The fish were kept in the AQH joint-aquariums system in October-December 2013, followed by fixation in RNA-preserving buffers and freezing during the space flight. The samples we returned to the Earth frozen in March 2013 and mRNAs from four fish were sequenced in organ-specific manner using HiSeq Illumina sequencing platform. The ground group fish treated in the same way was used as a control. The comparison between the groups revealed space group-specific specific mRNA expression pattern. More than 50 genes (including several types of myosins) were down-regulated in the space group. Moreover, we found an evidence for formation of space group-specific splicing variants of mRNA. Taking together, the data suggest that in spite of aquatic environment, space flight-associated factors have a strong effect on the activity of fish genome. This work was supported in part by subsidy of the Russian Government to support the Program of competitive growth of Kazan Federal University among world class academic centres and universities.

  10. Effects of dietary 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47) exposure in growing medaka fish (Oryzias latipes).

    PubMed

    González-Doncel, Miguel; Carbonell, Gregoria; García-Mauriño, José Enrique; Sastre, Salvador; Beltrán, Eulalia María; Fernàndez Torija, Carlos

    2016-09-01

    In this research work, we addressed the effects of a diet fortified with BDE-47 (0, 10, 100, 1000ng/g) dosed to 4-7 day-old post-hatch medaka fish for 40 days, followed by an 80-day depuration period. BDE-47 accumulation and overall growth were evaluated throughout the dosing period, and its elimination was quantified over the following 60 days. The histological condition of the thyroid gland, liver and gonads from the 1000ng BDE-47-treated fish were assessed 5 and 70days after exposures finished. The phenotypic males to females ratio was also quantified 70days after treatments finished. Sixty days after the BDE-47 exposures, reproductive capacity (i.e. fecundity, fertility and hatchability) was evaluated in mating groups for a 20-day period. BDE-47 exposure via food from larval through juvenile life stages of medaka fish resulted in steady accumulation with time dose-dependently. This accumulation tendency rapidly decreased after dosing ended. The growth rates showed a significant increase only at the highest concentration 70days after exposures finished. The histological survey did not reveal BDE-47-related alterations in the condition of the potential target organs. However, a morphometrical approach suggested BDE-47-related differences in the thickness of the epithelium that lines thyroid follicles. The reproduction studies showed comparable values for the fecundity, fertility and hatching rates. Dietary BDE-47 dosed for 40days to growing medaka fish did not alter the phenotypic sex ratios at maturity. The dietary approach used herein could not provide conclusive evidence of effects on medaka development and thriving despite the fact that BDE-47 underwent rapid accumulation in whole fish during the 40-day treatment. PMID:27497303

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

    PubMed Central

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

    2015-01-01

    The transgenerational consequences of environmental contaminant exposures of aquatic vertebrates have the potential for broad ecological impacts, yet are largely uninvestigated. Bisphenol A (BPA) and 17α-ethinylestradiol (EE2) are two ubiquitous estrogenic chemicals present in aquatic environments throughout the United States and many other countries. Aquatic organisms, including fish, are exposed to varying concentrations of these chemicals at various stages of their life history. Here, we tested the ability of embryonic exposure to BPA or EE2 to cause adverse health outcomes at later life stages and transgenerational abnormalities in medaka fish. Exposures of F0 medaka to either BPA (100 μg/L) or EE2 (0.05 μg/L) during the first 7 days of embryonic development, when germ cells are differentiating, did not cause any apparent phenotypic abnormalities in F0 or F1 generations, but led to a significant reduction in the fertilization rate in offspring two generations later (F2) as well as a reduction of embryo survival in offspring three generations later (F3). Our present observations suggest that BPA or EE2 exposure during development induces transgenerational phenotypes of reproductive impairment and compromised embryonic survival in fish of subsequent generations. These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments. PMID:25790734

  12. Androgen induces gonadal soma-derived factor, Gsdf, in XX gonads correlated to sex-reversal but not Dmrt1 directly, in the teleost fish, northern medaka (Oryzias sakaizumii).

    PubMed

    Horie, Yoshifumi; Myosho, Taijun; Sato, Tadashi; Sakaizumi, Mitsuru; Hamaguchi, Satoshi; Kobayashi, Tohru

    2016-11-15

    In the inbred HNI-II strain of Oryzias sakaizumii, Dmy and Gsdf are expressed in XY gonads from Stages 35 and 36, respectively, similarly to the inbred Hd-rR strain of Oryzias latipes. However, Dmrt1 respectively becomes detectable at Stage 36 and 5 days post hatching (dph) in the two strains. In XX HNI-II embryos, 17α-methyltestosterone (MT) induces Gsdf mRNA from Stage 36, accompanied by complete sex-reversal in all treated individuals (MT, 10 ng/mL), while Dmrt1 mRNA was first detectable at 5 dph. In XX d-rR, MT induced Gsdf mRNA expression and sex-reversal in only some of the treated individuals. Together, these results suggest the testis differentiation cascade in XY individuals differs between the HNI-II and Hd-rR strains. In addition, it is suggested that androgen-induced XX sex-reversal proceeds via an androgen-Gsdf-Dmrt1 cascade and that Gsdf plays an important role in sex-reversal in medaka. PMID:27452797

  13. Androgen induces gonadal soma-derived factor, Gsdf, in XX gonads correlated to sex-reversal but not Dmrt1 directly, in the teleost fish, northern medaka (Oryzias sakaizumii).

    PubMed

    Horie, Yoshifumi; Myosho, Taijun; Sato, Tadashi; Sakaizumi, Mitsuru; Hamaguchi, Satoshi; Kobayashi, Tohru

    2016-11-15

    In the inbred HNI-II strain of Oryzias sakaizumii, Dmy and Gsdf are expressed in XY gonads from Stages 35 and 36, respectively, similarly to the inbred Hd-rR strain of Oryzias latipes. However, Dmrt1 respectively becomes detectable at Stage 36 and 5 days post hatching (dph) in the two strains. In XX HNI-II embryos, 17α-methyltestosterone (MT) induces Gsdf mRNA from Stage 36, accompanied by complete sex-reversal in all treated individuals (MT, 10 ng/mL), while Dmrt1 mRNA was first detectable at 5 dph. In XX d-rR, MT induced Gsdf mRNA expression and sex-reversal in only some of the treated individuals. Together, these results suggest the testis differentiation cascade in XY individuals differs between the HNI-II and Hd-rR strains. In addition, it is suggested that androgen-induced XX sex-reversal proceeds via an androgen-Gsdf-Dmrt1 cascade and that Gsdf plays an important role in sex-reversal in medaka.

  14. 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

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

    EPA Science Inventory

    Abstract

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

  16. An essential role of the arginine vasotocin system in mate-guarding behaviors in triadic relationships of medaka fish (Oryzias latipes).

    PubMed

    Yokoi, Saori; Okuyama, Teruhiro; Kamei, Yasuhiro; Naruse, Kiyoshi; Taniguchi, Yoshihito; Ansai, Satoshi; Kinoshita, Masato; Young, Larry J; Takemori, Nobuaki; Kubo, Takeo; Takeuchi, Hideaki

    2015-01-01

    To increase individual male fitness, males of various species remain near a (potential) mating partner and repel their rivals (mate-guarding). Mate-guarding is assumed to be mediated by two different types of motivation: sexual motivation toward the opposite sex and competitive motivation toward the same sex. The genetic/molecular mechanisms underlying how mate presence affects male competitive motivation in a triadic relationship has remained largely unknown. Here we showed that male medaka fish prominently exhibit mate-guarding behavior. The presence of a female robustly triggers male-male competition for the female in a triadic relationship (2 males and 1 female). The male-male competition resulted in one male occupying a dominant position near the female while interfering with the other male's approach of the female. Paternity testing revealed that the dominant male had a significantly higher mating success rate than the other male in a triadic relationship. We next generated medaka mutants of arginine-vasotocin (avt) and its receptors (V1a1, V1a2) and revealed that two genes, avt and V1a2, are required for normal mate-guarding behavior. In addition, behavioral analysis of courtship behaviors in a dyadic relationship and aggressive behaviors within a male group revealed that avt mutant males displayed decreased sexual motivation but showed normal aggression. In contrast, heterozygote V1a2 mutant males displayed decreased aggression, but normal mate-guarding and courtship behavior. Thus, impaired mate-guarding in avt and V1a2 homozygote mutants may be due to the loss of sexual motivation toward the opposite sex, and not to the loss of competitive motivation toward rival males. The different behavioral phenotypes between avt, V1a2 heterozygote, and V1a2 homozygote mutants suggest that there are redundant systems to activate V1a2 and that endogenous ligands activating the receptor may differ according to the social context.

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

    EPA Science Inventory

    In: Environmental Sciences in the 21st Century: Paradigms, Opportunities, and Challenges: Abstract Book: SETAC 21st Annual Meeting, 12-16 November 2000, Nashville, TN. Society of Environmental Toxicology and Chemistry, Pensacola, FL. Pp. p. 262. (ERL,GB R816).

    Various i...

  18. A New Data-Mining Method to Search for Behavioral Properties That Induce Alignment and Their Involvement in Social Learning in Medaka Fish (Oryzias Latipes)

    PubMed Central

    Ochiai, Takashi; Suehiro, Yuji; Nishinari, Katsuhiro; Kubo, Takeo; Takeuchi, Hideaki

    2013-01-01

    Background Coordinated movement in social animal groups via social learning facilitates foraging activity. Few studies have examined the behavioral cause-and-effect between group members that mediates this social learning. Methodology/Principal Findings We first established a behavioral paradigm for visual food learning using medaka fish and demonstrated that a single fish can learn to associate a visual cue with a food reward. Grouped medaka fish (6 fish) learn to respond to the visual cue more rapidly than a single fish, indicating that medaka fish undergo social learning. We then established a data-mining method based on Kullback-Leibler divergence (KLD) to search for candidate behaviors that induce alignment and found that high-speed movement of a focal fish tended to induce alignment of the other members locally and transiently under free-swimming conditions without presentation of a visual cue. The high-speed movement of the informed and trained fish during visual cue presentation appeared to facilitate the alignment of naïve fish in response to some visual cues, thereby mediating social learning. Compared with naïve fish, the informed fish had a higher tendency to induce alignment of other naïve fish under free-swimming conditions without visual cue presentation, suggesting the involvement of individual recognition in social learning. Conclusions/Significance Behavioral cause-and-effect studies of the high-speed movement between fish group members will contribute to our understanding of the dynamics of social behaviors. The data-mining method used in the present study is a powerful method to search for candidates factors associated with inter-individual interactions using a dataset for time-series coordinate data of individuals. PMID:24039720

  19. An Essential Role of the Arginine Vasotocin System in Mate-Guarding Behaviors in Triadic Relationships of Medaka Fish (Oryzias latipes)

    PubMed Central

    Yokoi, Saori; Okuyama, Teruhiro; Kamei, Yasuhiro; Naruse, Kiyoshi; Taniguchi, Yoshihito; Ansai, Satoshi; Kinoshita, Masato; Young, Larry J.; Takemori, Nobuaki; Kubo, Takeo; Takeuchi, Hideaki

    2015-01-01

    To increase individual male fitness, males of various species remain near a (potential) mating partner and repel their rivals (mate-guarding). Mate-guarding is assumed to be mediated by two different types of motivation: sexual motivation toward the opposite sex and competitive motivation toward the same sex. The genetic/molecular mechanisms underlying how mate presence affects male competitive motivation in a triadic relationship has remained largely unknown. Here we showed that male medaka fish prominently exhibit mate-guarding behavior. The presence of a female robustly triggers male-male competition for the female in a triadic relationship (2 males and 1 female). The male-male competition resulted in one male occupying a dominant position near the female while interfering with the other male's approach of the female. Paternity testing revealed that the dominant male had a significantly higher mating success rate than the other male in a triadic relationship. We next generated medaka mutants of arginine-vasotocin (avt) and its receptors (V1a1, V1a2) and revealed that two genes, avt and V1a2, are required for normal mate-guarding behavior. In addition, behavioral analysis of courtship behaviors in a dyadic relationship and aggressive behaviors within a male group revealed that avt mutant males displayed decreased sexual motivation but showed normal aggression. In contrast, heterozygote V1a2 mutant males displayed decreased aggression, but normal mate-guarding and courtship behavior. Thus, impaired mate-guarding in avt and V1a2 homozygote mutants may be due to the loss of sexual motivation toward the opposite sex, and not to the loss of competitive motivation toward rival males. The different behavioral phenotypes between avt, V1a2 heterozygote, and V1a2 homozygote mutants suggest that there are redundant systems to activate V1a2 and that endogenous ligands activating the receptor may differ according to the social context. PMID:25719383

  20. An essential role of the arginine vasotocin system in mate-guarding behaviors in triadic relationships of medaka fish (Oryzias latipes).

    PubMed

    Yokoi, Saori; Okuyama, Teruhiro; Kamei, Yasuhiro; Naruse, Kiyoshi; Taniguchi, Yoshihito; Ansai, Satoshi; Kinoshita, Masato; Young, Larry J; Takemori, Nobuaki; Kubo, Takeo; Takeuchi, Hideaki

    2015-01-01

    To increase individual male fitness, males of various species remain near a (potential) mating partner and repel their rivals (mate-guarding). Mate-guarding is assumed to be mediated by two different types of motivation: sexual motivation toward the opposite sex and competitive motivation toward the same sex. The genetic/molecular mechanisms underlying how mate presence affects male competitive motivation in a triadic relationship has remained largely unknown. Here we showed that male medaka fish prominently exhibit mate-guarding behavior. The presence of a female robustly triggers male-male competition for the female in a triadic relationship (2 males and 1 female). The male-male competition resulted in one male occupying a dominant position near the female while interfering with the other male's approach of the female. Paternity testing revealed that the dominant male had a significantly higher mating success rate than the other male in a triadic relationship. We next generated medaka mutants of arginine-vasotocin (avt) and its receptors (V1a1, V1a2) and revealed that two genes, avt and V1a2, are required for normal mate-guarding behavior. In addition, behavioral analysis of courtship behaviors in a dyadic relationship and aggressive behaviors within a male group revealed that avt mutant males displayed decreased sexual motivation but showed normal aggression. In contrast, heterozygote V1a2 mutant males displayed decreased aggression, but normal mate-guarding and courtship behavior. Thus, impaired mate-guarding in avt and V1a2 homozygote mutants may be due to the loss of sexual motivation toward the opposite sex, and not to the loss of competitive motivation toward rival males. The different behavioral phenotypes between avt, V1a2 heterozygote, and V1a2 homozygote mutants suggest that there are redundant systems to activate V1a2 and that endogenous ligands activating the receptor may differ according to the social context. PMID:25719383

  1. The Japanese medaka (Oryzias latipes) model: applicability for investigating the immunosuppressive effects of the aquatic pollutant benzo[a]pyrene (BaP).

    PubMed

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

    2002-01-01

    Despite the fact that BaP is a carcinogen, mammalian immunosuppressant, and ubiquitous aquatic pollutant, knowledge regarding the effects of BaP on the immune system of fish is still lacking. To begin to fill this gap, studies were conducted in medaka to examine the effects and mechanisms by which BaP exposure might alter host immunocompetence. Fish, exposed by IP injection of BaP (2-600 microg/g BW), were examined after 48 h for effects upon immune function and CYP1A expression/activity. Benzo[a]pyrene, at a concentration below that which increased levels of CYPIA expression/activity (2 microg BaP/g BW) suppressed lymphocyte proliferation. Concentrations of BaP at 20 and 200 microg/g BW. suppressed antibody-forming cell (AFC) numbers, superoxide production, and host resistance against bacteria. In contrast, exposure to the low affinity aryl hydrocarbon receptor (AhR) agonist, benzo[e]pyrene (BeP), neither induced CYP1A expression nor altered immune function. Given the lack of immunosuppressive effects produced by BeP, and the fact that exposure to the AhR antagonist (and CYP1A inhibitor) alpha-naphthoflavone (ANF) ameliorated the suppressive effects of BaP upon AFC numbers, the AhR pathway (including CYP1A-mediated production of reactive BaP metabolites) appears important in mediating BaP-induced immunotoxicity in fish, as in mammals. In the past, the medaka has proven a successful model for assessing carcinogenic agents. These studies have demonstrated its utility for also determining the immunosuppressive effects of an important aquatic contaminant.

  2. Higher susceptibility to N-methyl-N'-nitro-N-nitrosoguanidine-induced tumorigenesis in an interstrain hybrid of the fish, Oryzias latipes (medaka).

    PubMed

    Hyodo-Taguchi, Y; Matsudaira, H

    1987-05-01

    Adult fish of an interstrain hybrid (F1) of inbred medaka, obtained from crosses between HO4C and HB32C, were exposed for 2 hr to an aqueous solution of the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine at concentrations of 15, 20, 25, 30, and 35 ppm. Survival and neoplastic changes were examined over a 6-month period. A large variety of neoplasms were induced, including melanoma, papilloma, ovarian tumors, olfactory epithelioma, branchioblastoma and fibroma. More than 60% of the tumors were classified as melanoma on the basis of histological examinations. A markedly higher cumulative incidence of the melanoma with a dose-related response was demonstrated in the F1 hybrid fish compared to the parental strains. The latent period for melanoma development, however, remained unchanged in F1 compared to the parents. The variety of tumors induced in the F1 fish was greater than in the parental strains. The results indicate the usefulness of F1 hybrid fish in testing the carcinogenicity of certain water-soluble chemicals, due to their high sensitivity. PMID:3112060

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

    EPA Science Inventory

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

  4. COMPARATIVE SENSITIVITY OF DIFFERENT LIFE-STAGES OF MEDAKA (ORYZIAS LATIPES) AND BROOK TROUT (SALVELINUS FONTINALIS) TO 2,3,7,8-TCDD

    EPA Science Inventory

    The early life stages of fish are known to be more sensitive than the adults to the toxicological effects of 2,3,7,8-tetrachlorodibenzo(p)dioxide (TCDD). TCDD concentrations in surface waters are sufficiently low that direct exposure of the developing embryo is unlikely to be o...

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    SciTech Connect

    Cooke, J.B.; Hinton, D.E.

    1994-12-31

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

  9. A method for real-time measurement of respiratory rhythms in medaka (Oryzias latipes) using computer vision for water quality monitoring.

    PubMed

    Zheng, Hongyuan; Liu, Rong; Zhang, Rong; Hu, Yanqing

    2014-02-01

    The respiratory rhythms of Japanese medaka is considered to be an efficient indicator for monitoring water quality since they are sensitive to chemicals and can be measured directly from the movement of fish gill tissue generated by their breathe. However, few methods have been established to measure the feature of small free-swimming fish intuitively. In this article, a method is proposed to measure the influence of the pollution to the Japanese medaka's respiratory rhythms with computer vision technology in real time. In order to get the images which contains the complete gill tissue remotely and steadily, a special object container and an experiment platform are designed. With the aim of capturing Japanese medaka's respiratory rhythms in real time, a set of image processing algorithms such as the color distribution table, Support Vector Machine (SVM), adaptive boosting (Adaboost) and mathematical morphology are applied. Then, in order to verify the effectiveness and accuracy of the whole method, fourteen groups of Japanese medakas are respectively exposed to copper ions solutions with different concentrations of 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 mg/L for 48 h. The comparison between the human eyes observation and the above method indicates that the data obtained through the method is generally accurate. We found that the respiratory rate of Japanese medaka showed a downward trend initially when exposed in the copper ions solution, afterwards fluctuated repeatly arounding the lower rate, before death, the respiratory rate rised slowly for a while. With the increase of concentration, this trend will be more obvious. But the above phenomenon is absolutely different from that in the standard dilution water. Moreover, the two kinds of special respiratory rhythm of medakas poisoning were discovered. This method can be widely applied to study some toxic substances' effects on Japanese medaka's respiratory rhythms and to assess the degree of risk of the water environment.

  10. Identification of p53-target genes in Danio rerio.

    PubMed

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  11. Identification of p53-target genes in Danio rerio

    PubMed Central

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M. Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species. PMID:27581768

  12. Identification of p53-target genes in Danio rerio.

    PubMed

    Mandriani, Barbara; Castellana, Stefano; Rinaldi, Carmela; Manzoni, Marta; Venuto, Santina; Rodriguez-Aznar, Eva; Galceran, Juan; Nieto, M Angela; Borsani, Giuseppe; Monti, Eugenio; Mazza, Tommaso; Merla, Giuseppe; Micale, Lucia

    2016-01-01

    To orchestrate the genomic response to cellular stress signals, p53 recognizes and binds to DNA containing specific and well-characterized p53-responsive elements (REs). Differences in RE sequences can strongly affect the p53 transactivation capacity and occur even between closely related species. Therefore, the identification and characterization of a species-specific p53 Binding sistes (BS) consensus sequence and of the associated target genes may help to provide new insights into the evolution of the p53 regulatory networks across different species. Although p53 functions were studied in a wide range of species, little is known about the p53-mediated transcriptional signature in Danio rerio. Here, we designed and biochemically validated a computational approach to identify novel p53 target genes in Danio rerio genome. Screening all the Danio rerio genome by pattern-matching-based analysis, we found p53 RE-like patterns proximal to 979 annotated Danio rerio genes. Prioritization analysis identified a subset of 134 candidate pattern-related genes, 31 of which have been investigated in further biochemical assays. Our study identified runx1, axin1, traf4a, hspa8, col4a5, necab2, and dnajc9 genes as novel direct p53 targets and 12 additional p53-controlled genes in Danio rerio genome. The proposed combinatorial approach resulted to be highly sensitive and robust for identifying new p53 target genes also in additional animal species.

  13. Ethylnitrosourea induces neoplasia in zebrafish (Danio rerio).

    PubMed

    Beckwith, L G; Moore, J L; Tsao-Wu, G S; Harshbarger, J C; Cheng, K C

    2000-03-01

    The zebrafish (Danio rerio) has been successfully used to discover hundreds of genes involved in development and organogenesis. To address the potential of zebrafish as a cancer model, it is important to determine the susceptibility of zebrafish to tumors. Germ line mutations are most commonly induced for zebrafish mutant screens by exposing adult male zebrafish to the alkylating agent, ethylnitrosourea (ENU). To determine whether ENU induces tumors, we compared the incidence of tumors in ENU-treated fish with untreated controls. Interestingly, 18 of 18 (100%) fish mutagenized with either 2.5 or 3.0 mM ENU developed epidermal papillomas, which numbered 1 to 22 per fish, within 1 year of treatment. The induced epidermal lesions included epidermal hyperplasia, flat papillomas (0.2 to 1.2 mm), and pedunculated papillomas (1.2 to 8 mm in greatest dimension), but no skin cancers. Angiogenesis was evident in papillomas larger than approximately 1 mm. All but two papillomas contained the three cell types (keratinocytes, club, and mucous cells) of normal zebrafish epidermis; histologic variants lacked either club cells or mucous cells. Two cavernous hemangiomas and a single malignant peripheral nerve sheath tumor were also found in the treated fish. None of five untreated controls developed tumors. These studies establish the feasibility of the zebrafish as an experimental model for the study of skin tumors. PMID:10744073

  14. Desert Springs: Deep Phylogeographic Structure in an Ancient Endemic Crustacean (Phreatomerus latipes)

    PubMed Central

    Guzik, Michelle T.; Adams, Mark A.; Murphy, Nicholas P.; Cooper, Steven J. B.; Austin, Andrew D.

    2012-01-01

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

  15. 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.

  16. Natural history of zebrafish (Danio rerio) in India.

    PubMed

    Arunachalam, Muthukumarasamy; Raja, Manickam; Vijayakumar, Chinnian; Malaiammal, Punniyam; Mayden, Richard L

    2013-03-01

    The Zebrafish, Danio rerio, is a well-known vertebrate model species widely used in research associated with biomedical areas and comparative and evolutionary biology. Interestingly, despite the importance of this species, little is known about the natural history, habitats, and native distribution. In our study of the species, we collected individuals from twenty-one wild populations from within the species' natural distribution, ranging from streams/rivers of the Western Ghats of Peninsular India to those of the Western and North-Eastern Himalayas. Habitat types are identified from various geographic locations. Danio rerio is largely confined to and most frequently associated with habitats of low flow and with a sandy substrate in secondary and tertiary channels connected with the main channel of a stream/river, or habitats adjacent to wetlands and paddy fields. These connections can be natural channels or man-made irrigation canals, beels, or culture ponds. Among the 21 populations, individuals from two populations (one from Orissa and another from Arunachal Pradesh) were much larger in size (total length) when compared to other populations. The general habitats of Danio rerio vary from small to large mountainous and lowland streams/rivers, wetlands, and paddy fields. PMID:23590398

  17. Developmental toxicity of three hexabromocyclododecane diastereoisomers in embryos of the marine medaka Oryzias melastigma.

    PubMed

    Hong, Haizheng; Shen, Rong; Liu, Wanxin; Li, Dongmei; Huang, Lingming; Shi, Dalin

    2015-12-15

    The composition of major hexabromocyclododecane (HBCD) diastereoisomers, i.e. α-, β-, and γ-HBCDs, in marine biota is different from that of the commercially available form (technical HBCD), which is used extensively for toxicological studies. To properly evaluate the impact of HBCDs, the embryos of Oryzias melastigma were used to examine the developmental toxicity of the individual diastereoisomers. Results showed that HBCD diastereoisomers at the environmentally realistic concentrations in the embryos induced malformation rate and heartbeat, and caused the appearance of apoptotic heart. In addition, α-, β-, and γ-HBCDs had similar potency to stimulate the generation of reactive oxygen species, consequently leading to apoptosis in O. melastigma embryos. The order of the developmental toxicity of α-, β-, and γ-HBCDs in O. melastigma embryos was different from that in zebrafish embryos studied previously, which highlighted the importance of using species from both fresh and salt water for toxicity assessment. PMID:26563546

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

    PubMed

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

    2013-12-01

    A preliminary study was conducted on the efficacy of Oryzias melastigma in consuming mosquito larva so as to control mosquito and mosquito borne diseases, and enhancing its reproductive success using supplementary feed. Oryzias melastigma is a larvivore fish and widely distributed in the shallow water, wetlands of Gangetic plains and peninsular India. These studies indicate that O. melastigma is a prolific breeder and gregarious feeder of mosquito larvae. Increased reproduction by providing different supplementary feed, of which Ulothrix acted remarkably, may aid in wide spread use of this fish as a biological control measure against mosquitoes. One adult fish of any sex can consume 87.1% first instars mosquito larvae/day. So, early stages of mosquito larvae are effectively controlled, as compared to other successive stages. Ulothrix has considerable effect on egg production, successful hatching and regaining reproductive maturity of female in surprisingly quicker interval. PMID:23807913

  19. Leptin receptor-deficient (knockout) medaka, Oryzias latipes, show chronical up-regulated levels of orexigenic neuropeptides, elevated food intake and stage specific effects on growth and fat allocation.

    PubMed

    Chisada, Shin-ichi; Kurokawa, Tadahide; Murashita, Koji; Rønnestad, Ivar; Taniguchi, Yoshihito; Toyoda, Atsushi; Sakaki, Yoshiyuki; Takeda, Shunichi; Yoshiura, Yasutoshi

    2014-01-01

    The first studies that identified leptin and its receptor (LepR) in mammals were based on mutant animals that displayed dramatic changes in body-weight and regulation of energy homeostasis. Subsequent studies have shown that a deficiency of leptin or LepR in homoeothermic mammals results in hyperphagia, obesity, infertility and a number of other abnormalities. The physiological roles of leptin-mediated signaling in ectothermic teleosts are still being explored. Here, we produced medaka with homozygous LepR gene mutation using the targeting induced local lesions in a genome method. This knockout mutant had a point mutation of cysteine for stop codon at the 357th amino acid just before the leptin-binding domain. The evidence for loss of function of leptin-mediated signaling in the mutant is based on a lack of response to feeding in the expression of key appetite-related neuropeptides in the diencephalon. The mutant lepr−/− medaka expressed constant up-regulated levels of mRNA for the orexigenic neuropeptide Ya and agouti-related protein and a suppressed level of anorexigenic proopiomelanocortin 1 in the diencephalon independent of feeding, which suggests that the mutant did not possess functional LepR. Phenotypes of the LepR-mutant medaka were analyzed in order to understand the effects on food intake, growth, and fat accumulation in the tissues. The food intake of the mutant medaka was higher in post-juveniles and adult stages than that of wild-type (WT) fish. The hyperphagia led to a high growth rate at the post-juvenile stage, but did not to significant alterations in final adult body size. There was no additional deposition of fat in the liver and muscle in the post-juvenile and adult mutants, or in the blood plasma in the adult mutant. However, adult LepR mutants possessed large deposits of visceral fat, unlike in the WT fish, in which there were none. Our analysis confirms that LepR in medaka exert a powerful influence on the control on food intake. Further analyses using the mutant will contribute to a better understanding of the role of leptin in fish. This is the first study to produce fish with leptin receptor deficiency.

  20. MX [3-Chloro-4-(Dichloromethyl)-5-Hydroxy-2[5H]-Furanone], A Drinking-Water Carcinogen, Does Not Induce Mutations in the Liver of Cii Transgenic Medaka (Oryzias latipes)

    EPA Science Inventory

    Mutagenicity assays with Salmonella have shown that 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX), a drinking water disinfection by-product is a potent mutagen, accounting for about one third of the mutagenic potency/potential of chlorinated drinking water. The abilit...

  1. Calsequestrins in skeletal and cardiac muscle from adult Danio rerio.

    PubMed

    Furlan, Sandra; Mosole, Simone; Murgia, Marta; Nagaraj, Nagarjuna; Argenton, Francesco; Volpe, Pompeo; Nori, Alessandra

    2016-04-01

    Calsequestrin (Casq) is a high capacity, low affinity Ca(2+)-binding protein, critical for Ca(2+)-buffering in cardiac and skeletal muscle sarcoplasmic reticulum. All vertebrates have multiple genes encoding for different Casq isoforms. Increasing interest has been focused on mammalian and human Casq genes since mutations of both cardiac (Casq2) and skeletal muscle (Casq1) isoforms cause different, and sometime severe, human pathologies. Danio rerio (zebrafish) is a powerful model for studying function and mutations of human proteins. In this work, expression, biochemical properties cellular and sub-cellular localization of D. rerio native Casq isoforms are investigated. By quantitative PCR, three mRNAs were detected in skeletal muscle and heart with different abundances. Three zebrafish Casqs: Casq1a, Casq1b and Casq2 were identified by mass spectrometry (Data are available via ProteomeXchange with identifier PXD002455). Skeletal and cardiac zebrafish calsequestrins share properties with mammalian Casq1 and Casq2. Skeletal Casqs were found primarily, but not exclusively, at the sarcomere Z-line level where terminal cisternae of sarcoplasmic reticulum are located. PMID:26585961

  2. Reconstruction of Danio rerio Metabolic Model Accounting for Subcellular Compartmentalisation

    PubMed Central

    Bekaert, Michaël

    2012-01-01

    Plant and microbial metabolic engineering is commonly used in the production of functional foods and quality trait improvement. Computational model-based approaches have been used in this important endeavour. However, to date, fish metabolic models have only been scarcely and partially developed, in marked contrast to their prominent success in metabolic engineering. In this study we present the reconstruction of fully compartmentalised models of the Danio rerio (zebrafish) on a global scale. This reconstruction involves extraction of known biochemical reactions in D. rerio for both primary and secondary metabolism and the implementation of methods for determining subcellular localisation and assignment of enzymes. The reconstructed model (ZebraGEM) is amenable for constraint-based modelling analysis, and accounts for 4,988 genes coding for 2,406 gene-associated reactions and only 418 non-gene-associated reactions. A set of computational validations (i.e., simulations of known metabolic functionalities and experimental data) strongly testifies to the predictive ability of the model. Overall, the reconstructed model is expected to lay down the foundations for computational-based rational design of fish metabolic engineering in aquaculture. PMID:23166792

  3. 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.

  4. 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.

  5. Heavy metal-induced differential gene expression of metallothionein in Javanese medaka, Oryzias javanicus.

    PubMed

    Woo, Seonock; Yum, Seungshic; Jung, Jee Hyun; Shim, Won Joon; Lee, Chang-Hoon; Lee, Taek-Kyun

    2006-01-01

    A metallothionein (MT) gene was isolated for the first time from Javanese medaka, Oryzias javanicus, which shows high adaptability from freshwater to seawater. The full-length cDNA of MT from O. javanicus (OjaMT) comprises 349 bp, excluding the poly(A)+ stretch, and codes for a total of 60 amino acids. The positions of cysteine residues are highly conserved. The pattern of OjaMT expression induced by six heavy metals was analyzed via real-time quantitative polymerase chain reaction (PCR). The level of hepatic OjaMT mRNA was increased in a dose-dependent manner by Ag, Cd, Cu, and Zn after 24 h of exposure. However, after Cr and Ni exposure, a significant decrease in OjaMT levels was observed. Cadmium-induced OjaMT expression was detectable in fishes as young as 3 months. After Cd exposure, OjaMT induction was prominent in intestine and liver and moderate in muscle and gill. OjaMT mRNA levels could represent a good biomarker for monitoring heavy metals in seawater. PMID:16967182

  6. Effects of CO2-driven ocean acidification on early life stages of marine medaka (Oryzias melastigma)

    NASA Astrophysics Data System (ADS)

    Mu, J.; Jin, F.; Wang, J.; Zheng, N.; Cong, Y.

    2015-06-01

    The potential effects of high CO2 and associated ocean acidification (OA) in marine fishes and other non-calcified organisms are less well understood. In this study, we investigated the responses of early life stages (ELS) of marine medaka (Oryzias melastigma) exposed to a series of experimental manipulation of CO2 levels. Results showed that CO2-driven seawater acidification (pH 7.6 and pH 7.2) had no detectable effect on hatching time, hatching rate, or heart rate of embryos. However, the deformity rate of larvae in the pH 7.2 treatment was significantly higher than that in the control treatment. There is no significant difference between the left and right otolith areas in each treatment. However, the average otolith area of larvae in the pH 7.6 treatment was significantly smaller than that in the control. Such alterations in the developmental abnormalities and otolith size of marine medaka larvae due to elevated-CO2 levels suggests that this species will be increasingly challenged by future OA. Further studies of the impacts of OA on marine fish to assess whether or not the environmental influence in one generation can affect the later life history and the phenotype of subsequent generations are needed.

  7. Effects of CO2-driven ocean acidification on early life stages of marine medaka (Oryzias melastigma)

    NASA Astrophysics Data System (ADS)

    Mu, J.; Jin, F.; Wang, J.; Zheng, N.; Cong, Y.

    2015-01-01

    The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of ocean acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in early life stage of marine medaka.

  8. The behaviour and ecology of the zebrafish, Danio rerio.

    PubMed

    Spence, Rowena; Gerlach, Gabriele; Lawrence, Christian; Smith, Carl

    2008-02-01

    The zebrafish Danio rerio, is an important model organism in developmental genetics, neurophysiology and biomedicine, but little is known about its natural ecology and behaviour. It is a small, shoaling cyprinid, native to the flood-plains of the Indian subcontinent, where it is found in shallow, slow-flowing waters. Zebrafish are group spawners and egg scatterers, although females are choosy with respect to sites for oviposition and males defend territories around such sites. Laboratory studies of zebrafish behaviour have encompassed shoaling, foraging, reproduction, sensory perception and learning. These studies are reviewed in relation to the suitability of the zebrafish as a model for studies on cognition and learning, development, behavioural and evolutionary ecology, and behavioural genetics.

  9. Salinity influences on the uptake of silver nanoparticles and silver nitrate by marine medaka (Oryzias melastigma).

    PubMed

    Wang, Jian; Wang, Wen-Xiong

    2014-03-01

    With increasing use of silver nanoparticles (AgNPs), concerns about their potential deleterious effects on aquatic ecosystems have increased. Most previous studies have focused on the toxicity of AgNPs while their bioavailability has been seldom investigated. The present study examined the effects of salinity on the aggregation kinetics as well as the bioavailability of commercial 80-nm citrate-coated AgNPs (c-AgNPs) in the presence or absence of a nonionic surfactant (Tween 20) to marine medaka (Oryzias melastigma). In addition, the uptake of soluble Ag was quantified for comparison and for deducting the uptake of soluble Ag during AgNP exposure by applying a biokinetic model. The authors found that the addition of Tween 20 immediately slowed down the process of aggregation of AgNPs, and an elevated amount of Tween 20 (20 µM) kept AgNPs well dispersed, even in the 30-psu salinity medium. Uptake rate constants (ku ) of AgNPs were less than half the soluble Ag at low salinities (1 psu and 5 psu), while limited bioavailability of c-AgNPs was observed at high salinities (15 psu and 30 psu). However, the Tween 20-stabilized AgNPs (t-AgNPs) were accumulated by medaka at comparable rates as the soluble Ag, indicating the importance of dispersion for bioavailability of AgNPs in a highly ionic environment. The present study provided the first insight of the bioavailability of AgNPs to fish in a high-ionic environment. More studies are needed to gain a full understanding of bioavailability of AgNPs in marine environments.

  10. Prochloraz causes irreversible masculinization of zebrafish (Danio rerio).

    PubMed

    Baumann, Lisa; Knörr, Susanne; Keiter, Susanne; Nagel, Tina; Segner, Helmut; Braunbeck, Thomas

    2015-11-01

    The aim of the present study was to investigate the persistence of endocrine effects by prochloraz, a fungicide known to have multiple effects on the endocrine system of vertebrates. Since discontinuous exposure is particularly relevant in aquatic ecosystems, an exposure scenario with an exposure phase and a subsequent recovery period was chosen to assess the potential for reversibility of effects by prochloraz on the sexual development of zebrafish (Danio rerio). Zebrafish were exposed to different concentrations of prochloraz (10-300 μg/L) until 60 days post hatch (dph), which includes the period of sexual differentiation. For the subsequent 40 days, fish were either held in clean water for depuration or under further continuous exposure. Histological investigations of the gonads revealed persistent effects on sexual differentiation. The sex ratio was skewed towards males and significantly more intersex individuals were found after exposure to prochloraz at 60 dph. No intersex fish, but masculinized sex ratios were still present after the depuration period, documenting that prochloraz irreversibly affects the sexual development of zebrafish. PMID:25163568

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

    PubMed

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

    2015-11-01

    The adult zebrafish (Danio rerio) were exposed to treated-effluent concentration of bisphenol A (BPA) or 17β-estradiol (E2) for 6 months to evaluate their effects on behavioral characteristics: motor behavior, aggression, group preference, novel tank test and light/dark preference. E2 exposure evidently dampened fish locomotor activity, while BPA exposure had no marked effect. Interestingly, BPA-exposed fish reduced their aggressive behavior compared with control or E2. Both BPA and E2 exposure induced a significant decrease in group preference, as well as a weaker adaptability to new environment, exhibiting lower latency to reach the top, more entries to the top, longer time spent in the top, fewer frequent freezing, and fewer erratic movements. Furthermore, the circadian rhythmicity of light/dark preference was altered by either BPA or E2 exposure. Our results suggest that chronic exposure of treated-effluent concentration BPA or E2 induced various behavioral anomalies in adult fish and enhanced ecological risk to wildlife. PMID:26204572

  12. Pleistophora hyphessobryconis (Microsporidia) infecting zebrafish Danio rerio in research facilities.

    PubMed

    Sanders, Justin L; Lawrence, Christian; Nichols, Donald K; Brubaker, Jeffrey F; Peterson, Tracy S; Murray, Katrina N; Kent, Michael L

    2010-07-26

    Zebrafish Danio rerio are important models for biomedical research, and thus, there is an increased concern about diseases afflicting them. Here we describe infections by Pleistophora hyphessobryconis (Microsporidia) in zebrafish from 3 laboratories. As reported in other aquarium fishes, affected zebrafish exhibited massive infections in the skeletal muscle, with no involvement of smooth or cardiac muscle. In addition, numerous spores within macrophages were observed in the visceral organs, including the ovaries. Transmission studies and ribosomal RNA (rRNA) gene sequence comparisons confirmed that the parasite from zebrafish was P. hyphessobryconis as described from neon tetra Paracheirodon innesi. Ten 15 d old zebrafish were exposed to P. hyphessobryconis collected from 1 infected neon tetra, and 7 of 10 fish became infected. Comparison of P. hyphessobryconis small subunit rRNA gene sequence from neon tetra with that obtained from zebrafish was nearly identical, with < 1% difference. Given the severity of infections, P. hyphessobryconis should be added to the list of pathogens that should be avoided in zebrafish research facilities, and it would be prudent to avoid mixing zebrafish used in research with other aquarium fishes. PMID:20853741

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

    NASA Astrophysics Data System (ADS)

    Muller, M.; Aceto, J.; Dalcq, J.; Alestrom, P.; Nourizadeh-Lillabadi, R.; Goerlich, R.; Schiller, V.; Winkler, C.; Renn, J.; Eberius, M.; Slenzka, K.

    2008-06-01

    Small fish models, mainly zebrafish (Danio rerio) and medaka (Oryzias latipes), have been used for many years as powerful model systems for vertebrate developmental biology. Moreover, these species are increasingly recognized as valuable systems to study vertebrate physiology, pathology, pharmacology and toxicology, including in particular bone physiology. The biology of small fishes presents many advantages, such as transparency of the embryos, external and rapid development, small size and easy reproduction. Further characteristics are particularly useful for space research or for large scale screening approaches. Finally, many technologies for easily characterizing bones are available. Our objective is to investigate the changes induced by microgravity in small fish. By combining whole genome analysis (microarray, DNA methylation, chromatin modification) with live imaging of selected genes in transgenic animals, a comprehensive and integrated characterization of physiological changes in space could be gained, especially concerning bone physiology.

  14. Infrared laser-mediated local gene induction in medaka, zebrafish and Arabidopsis thaliana.

    PubMed

    Deguchi, Tomonori; Itoh, Mariko; Urawa, Hiroko; Matsumoto, Tomohiro; Nakayama, Sohei; Kawasaki, Takashi; Kitano, Takeshi; Oda, Shoji; Mitani, Hiroshi; Takahashi, Taku; Todo, Takeshi; Sato, Junichi; Okada, Kiyotaka; Hatta, Kohei; Yuba, Shunsuke; Kamei, Yasuhiro

    2009-12-01

    Heat shock promoters are powerful tools for the precise control of exogenous gene induction in living organisms. In addition to the temporal control of gene expression, the analysis of gene function can also require spatial restriction. Recently, we reported a new method for in vivo, single-cell gene induction using an infrared laser-evoked gene operator (IR-LEGO) system in living nematodes (Caenorhabditis elegans). It was demonstrated that infrared (IR) irradiation could induce gene expression in single cells without incurring cellular damage. Here, we report the application of IR-LEGO to the small fish, medaka (Japanese killifish; Oryzias latipes) and zebrafish (Danio rerio), and a higher plant (Arabidopsis thaliana). Using easily observable reporter genes, we successfully induced gene expression in various tissues in these living organisms. IR-LEGO has the potential to be a useful tool in extensive research fields for cell/tissue marking or targeted gene expression in local tissues of small fish and plants.

  15. PCR-based analysis of mitochondrial DNA copy number, mitochondrial DNA damage, and nuclear DNA damage

    PubMed Central

    Gonzalez-Hunt, Claudia P.; Rooney, John P.; Ryde, Ian T.; Anbalagan, Charumathi; Joglekar, Rashmi

    2016-01-01

    Because of the role DNA damage and depletion play in human disease, it is important to develop and improve tools to assess these endpoints. This unit describes PCR-based methods to measure nuclear and mitochondrial DNA damage and copy number. Long amplicon quantitative polymerase chain reaction (LA-QPCR) is used to detect DNA damage by measuring the number of polymerase-inhibiting lesions present based on the amount of PCR amplification; real-time PCR (RT-PCR) is used to calculate genome content. In this unit we provide step-by-step instructions to perform these assays in Homo sapiens, Mus musculus, Rattus norvegicus, Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, Oryzias latipes, Fundulus grandis, and Fundulus heteroclitus, and discuss the advantages and disadvantages of these assays. PMID:26828332

  16. The taste system of small fish species.

    PubMed

    Okada, Shinji

    2015-01-01

    Small fish species such as the zebrafish (Danio rerio) and medaka fish (Oryzias latipes) are advantageous animal models and have been used as model organisms in many research areas. However, they have not been utilized for studying the taste system, primarily because of a dearth of molecular biological knowledge. Quantitative methods for analyzing the taste preferences of fish species have also been lacking. Recent progress of the fish genome project has enabled the elucidation of the molecular mechanisms of taste sensation. Taste receptors and a number of signal transduction molecules have been identified. Additionally, the development of quantitative methods of feeding using fluorescently labeled artificial foods has demonstrated taste preferences in small fish species. Comparisons between these results in fish and reports on mammals have proposed a general logic and evolution of vertebrate taste systems. Analysis on the transsynaptic tracer-expressing transgenic medaka fish also suggests the usefulness of small fish in the research of neural circuits for taste.

  17. SalmonDB: a bioinformatics resource for Salmo salar and Oncorhynchus mykiss

    PubMed Central

    Di Génova, Alex; Aravena, Andrés; Zapata, Luis; González, Mauricio; Maass, Alejandro; Iturra, Patricia

    2011-01-01

    SalmonDB is a new multiorganism database containing EST sequences from Salmo salar, Oncorhynchus mykiss and the whole genome sequence of Danio rerio, Gasterosteus aculeatus, Tetraodon nigroviridis, Oryzias latipes and Takifugu rubripes, built with core components from GMOD project, GOPArc system and the BioMart project. The information provided by this resource includes Gene Ontology terms, metabolic pathways, SNP prediction, CDS prediction, orthologs prediction, several precalculated BLAST searches and domains. It also provides a BLAST server for matching user-provided sequences to any of the databases and an advanced query tool (BioMart) that allows easy browsing of EST databases with user-defined criteria. These tools make SalmonDB database a valuable resource for researchers searching for transcripts and genomic information regarding S. salar and other salmonid species. The database is expected to grow in the near feature, particularly with the S. salar genome sequencing project. Database URL: http://genomicasalmones.dim.uchile.cl/ PMID:22120661

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

    PubMed

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

    2016-02-01

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect thyroid endocrine system, but little is known of such effects or underlying mechanisms in fish. In the present study, we evaluated the effects of fluoride on growth performance, thyroid histopathology, thyroid hormone levels, and gene expressions in the HPT axis in male zebrafish (Danio rerio) exposed to different determined concentrations of 0.1, 0.9, 2.0 and 4.1 M of fluoride to investigate the effects of fluoride on thyroid endocrine system and the potential toxic mechanisms caused by fluoride. The results indicated that the growth of the male zebrafish used in the experiments was significantly inhibited, the thyroid microtrastructure was changed, and the levels of T3 and T4 were disturbed in fluoride-exposed male fish. In addition, the expressional profiles of genes in HPT axis displayed alteration. The expressions of all studied genes were significantly increased in all fluoride-exposed male fish after exposure for 45 days. The transcriptional levels of corticotrophin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroglobulin (TG), sodium iodide symporter (NIS), iodothyronine I (DIO1), and thyroid hormone receptor alpha (TRα) were also elevated in all fluoride-exposed male fish after 90 days of exposure, while the inconsistent expressions were found in the mRNA of iodothyronineⅡ (DIO2), UDP glucuronosyltransferase 1 family a, b (UGT1ab), transthyretin (TTR), and thyroid hormone receptor beta (TRβ). These results demonstrated that fluoride could notably inhibit the growth of zebrafish, and significantly affect thyroid endocrine system by changing the microtrastructure of thyroid, altering thyroid hormone levels and endocrine-related gene expressions in male zebrafish. All above indicated that fluoride could pose a great threat to thyroid endocrine system, thus detrimentally affected the normal function of thyroid of male zebrafish. PMID:26748264

  19. Vascular toxicity of silver nanoparticles to developing zebrafish (Danio rerio).

    PubMed

    Gao, Jiejun; Mahapatra, Cecon T; Mapes, Christopher D; Khlebnikova, Maria; Wei, Alexander; Sepúlveda, Marisol S

    2016-11-01

    Nanoparticles (NPs, 1-100 nm) can enter the environment and result in exposure to humans and other organisms leading to potential adverse health effects. The aim of the present study is to evaluate the effects of early life exposure to polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs, 50 nm), particularly with respect to vascular toxicity on zebrafish embryos and larvae (Danio rerio). Previously published data has suggested that PVP-AgNP exposure can inhibit the expression of genes within the vascular endothelial growth factor (VEGF) signaling pathway, leading to delayed and abnormal vascular development. Here, we show that early acute exposure (0-12 h post-fertilization, hpf) of embryos to PVP-AgNPs at 1 mg/L or higher results in a transient, dose-dependent induction in VEGF-related gene expression that returns to baseline levels at hatching (72 hpf). Hatching results in normoxia, negating the effects of AgNPs on vascular development. Interestingly, increased gene transcription was not followed by the production of associated proteins within the VEGF pathway, which we attribute to NP-induced stress in the endoplasmic reticulum (ER). The impaired translation may be responsible for the observed delays in vascular development at later stages, and for smaller larvae size at hatching. Silver ion (Ag(+)) concentrations were < 0.001 mg/L at all times, with no significant effects on the VEGF pathway. We propose that PVP-AgNPs temporarily delay embryonic vascular development by interfering with oxygen diffusion into the egg, leading to hypoxic conditions and ER stress.

  20. Simvastatin effects on detoxification mechanisms in Danio rerio embryos.

    PubMed

    Cunha, V; Santos, M M; Moradas-Ferreira, P; Ferreira, M

    2016-06-01

    The transcription and protein activity of defence mechanisms such as ABC transporters, phase I and II of cellular detoxification and antioxidant enzymes can be altered in the presence of emerging contaminants such as pharmaceuticals impacting the overall detoxification mechanism. The present work aimed to characterise the effects of simvastatin on the detoxification mechanisms of embryonic stages of Danio rerio. In a first approach, constitutive transcription of key genes involved in detoxification was determined. Embryos were collected at different developmental stages, and transcription patterns of genes coding for ABC transporters, phase I and II and oxidative stress were analysed. With exception of abcc2, all genes seem to be from maternal transfer (0-2 hpf). Embryos were then exposed to different concentrations of simvastatin (5 and 50 μg/L), verapamil and MK571 (10 μM; ABC protein inhibitors) and a combination of simvastatin and ABC inhibitors. mRNA expression levels of abcb4, abcc1, abcc2, abcg2, cyp1a, cyp3a65, gst, sod, cat was evaluated. Accumulation assays to measure ABC proteins activity and activity of EROD, GST, CAT and Cu/ZnSOD, were also undertaken. Simvastatin acted as a weak inhibitor of ABC proteins and increased EROD and GST activity, whereas Cu/ZnSOD and CAT activity were decreased. Simvastatin up-regulated abcb4 and cyp3a65 transcription (both concentrations), as well as abcc1 and abcc2 at 50 μg/L, and down-regulated gst, sod, cat at 5 μg/L. In conclusion, our data revealed the interaction of simvastatin with detoxification mechanisms highlighting the importance of monitoring the presence of this emerging contaminant in aquatic environments.

  1. Husbandry of zebrafish, Danio rerio, and the cortisol stress response.

    PubMed

    Pavlidis, Michail; Digka, Nikoletta; Theodoridi, Antonia; Campo, Aurora; Barsakis, Konstantinos; Skouradakis, Gregoris; Samaras, Athanasios; Tsalafouta, Alexandra

    2013-12-01

    The effect of common husbandry conditions (crowding, social environment, water quality, handling, and background color) on the cortisol stress response in adult zebrafish, Danio rerio, was investigated to check the usefulness of zebrafish as a model organism in aquaculture research. In addition, a noninvasive methodology for assessing stress was evaluated. Zebrafish showed a fast cortisol response with high values at 30 min that returned to basal levels within 2 h of poststress. There was a significant positive correlation between trunk cortisol concentrations and the free water cortisol rate (r(2)=0.829-0.850, p<0.001), indicating that measurement of the water-borne cortisol release rate may serve as a noninvasive and reliable stress indicator at the population level. Crowding resulted in 13- to 21-fold greater mean trunk cortisol concentrations compared with controls. However, even at low stocking density (2-5 fish/L), the maintenance cost was higher than the one at higher densities (10 fish/L) due to the formation of dominance hierarchies. The background color affected trunk cortisol concentrations, with fish exposed to brighter backgrounds (green and white) showing 3- to 8-fold greater mean trunk cortisol concentrations than fish exposed to a black background or transparent aquaria. Fish exposed to high stocking densities for 2 h or 5 days had similar high mean trunk cortisol levels, indicating that exposure of fish for the period of 2 h to a specific stressor may represent a chronic situation in zebrafish. It is concluded that adult laboratory zebrafish had a preference for a transparent or black background aquarium, at a number of 10 individuals per 2 L of available water volume, to express their normal behavior and avoid increased cortisol stress reaction.

  2. Vascular toxicity of silver nanoparticles to developing zebrafish (Danio rerio).

    PubMed

    Gao, Jiejun; Mahapatra, Cecon T; Mapes, Christopher D; Khlebnikova, Maria; Wei, Alexander; Sepúlveda, Marisol S

    2016-11-01

    Nanoparticles (NPs, 1-100 nm) can enter the environment and result in exposure to humans and other organisms leading to potential adverse health effects. The aim of the present study is to evaluate the effects of early life exposure to polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs, 50 nm), particularly with respect to vascular toxicity on zebrafish embryos and larvae (Danio rerio). Previously published data has suggested that PVP-AgNP exposure can inhibit the expression of genes within the vascular endothelial growth factor (VEGF) signaling pathway, leading to delayed and abnormal vascular development. Here, we show that early acute exposure (0-12 h post-fertilization, hpf) of embryos to PVP-AgNPs at 1 mg/L or higher results in a transient, dose-dependent induction in VEGF-related gene expression that returns to baseline levels at hatching (72 hpf). Hatching results in normoxia, negating the effects of AgNPs on vascular development. Interestingly, increased gene transcription was not followed by the production of associated proteins within the VEGF pathway, which we attribute to NP-induced stress in the endoplasmic reticulum (ER). The impaired translation may be responsible for the observed delays in vascular development at later stages, and for smaller larvae size at hatching. Silver ion (Ag(+)) concentrations were < 0.001 mg/L at all times, with no significant effects on the VEGF pathway. We propose that PVP-AgNPs temporarily delay embryonic vascular development by interfering with oxygen diffusion into the egg, leading to hypoxic conditions and ER stress. PMID:27499207

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

    PubMed

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

    2016-02-01

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

  4. Cytoskeletal and cellular adhesion proteins in zebrafish (Danio rerio) myogenesis.

    PubMed

    Costa, M L; Escaleira, R; Manasfi, M; de Souza, L F; Mermelstein, C S

    2003-08-01

    The current myogenesis and myofibrillogenesis model has been based mostly on in vitro cell culture studies, and, to a lesser extent, on in situ studies in avian and mammalian embryos. While the more isolated artificial conditions of cells in culture permitted careful structural analysis, the actual in situ cellular structures have not been described in detail because the embryos are more difficult to section and manipulate. To overcome these difficulties, we used the optically clear and easy to handle embryos of the zebrafish Danio rerio. We monitored the expression of cytoskeletal and cell-adhesion proteins (actin, myosin, desmin, alpha-actinin, troponin, titin, vimentin and vinculin) using immunofluorescence microscopy and video-enhanced, background-subtracted, differential interference contrast of 24- to 48-h zebrafish embryos. In the mature myotome, the mononucleated myoblasts displayed periodic striations for all sarcomeric proteins tested. The changes in desmin distribution from aggregates to perinuclear and striated forms, although following the same sequence, occurred much faster than in other models. All desmin-positive cells were also positive for myofibrillar proteins and striated, in contrast to that which occurs in cell cultures. Vimentin appeared to be striated in mature cells, while it is developmentally down-regulated in vitro. The whole connective tissue septum between the somites was positive for adhesion proteins such as vinculin, instead of the isolated adhesion plaques observed in cell cultures. The differences in the myogenesis of zebrafish in situ and in cell culture in vitro suggest that some of the previously observed structures and protein distributions in cultures could be methodological artifacts.

  5. Characterization of snakehead rhabdovirus infection in zebrafish (Danio rerio).

    PubMed

    Phelan, Peter E; Pressley, Meagan E; Witten, P Eckhard; Mellon, Mark T; Blake, Sharon; Kim, Carol H

    2005-02-01

    The zebrafish, Danio rerio, has become recognized as a valuable model for the study of development, genetics, and toxicology. Recently, the zebrafish has been recognized as a useful model for infectious disease and immunity. In this study, the pathogenesis and antiviral immune response of zebrafish to experimental snakehead rhabdovirus (SHRV) infection was characterized. Zebrafish 24 h postfertilization to 30 days postfertilization were susceptible to infection by immersion in 10(6) 50% tissue culture infective doses (TCID50) of SHRV/ml, and adult zebrafish were susceptible to infection by intraperitoneal (i.p.) injection of 10(5) TCID50 of SHRV/ml. Mortalities exceeded 40% in infected fish, and clinical presentation of infection included petechial hemorrhaging, redness of the abdomen, and erratic swim behavior. Virus reisolation and reverse transcription-PCR analysis of the viral nucleocapsid gene confirmed the presence of SHRV. Histological sections of moribund embryonic and juvenile fish revealed necrosis of the pharyngeal epithelium and liver, in addition to congestion of the swim bladder by cell debris. Histopathology in adult fish injected i.p. was confined to the site of injection. The antiviral response in zebrafish was monitored by quantitative real-time PCR analysis of zebrafish interferon (IFN) and Mx expression. IFN and Mx levels were elevated in zebrafish exposed to SHRV, although expression and intensity differed with age and route of infection. This study is the first to examine the pathogenesis of SHRV infection in zebrafish. Furthermore, this study is the first to describe experimental infection of zebrafish embryos with a viral pathogen, which will be important for future experiments involving targeted gene disruption and forward genetic screens.

  6. LPS response and tolerance in the zebrafish (Danio rerio)

    PubMed Central

    Novoa, B.; Bowman, TV.; Zon, L.; Figueras, A

    2009-01-01

    Zebrafish (Danio rerio) has been used in the present work to study the fish response to bacterial lipopolysaccharide (LPS) exposure and LPS tolerance. These mechanisms are not completely understood in mammals and, presently, are totally unknown in fish. Zebrafish larval survival was assessed following treatment with various types of LPS at a variety of concentrations to determine the sensitivity of zebrafish to LPS-induced immune activation. In addition, fish pre-treated with a sublethal concentration of LPS did not die after exposure to a lethal concentration of LPS demonstrating, for the first time, that LPS tolerance also happens in fish. The time interval between pretreatment and secondary exposure as well as the type of pretreatment dictated the strength of protection. Since zebrafish are in intimate contact with microorganisms, the high resistance of fish to LPS suggests that there must be a tight control of the LPS receptor cluster in order to avoid an excess of inflammation. One of these components is CXCR4, which has previously been shown to regulate the signal transduced by TLR4. Treating fish with AMD 3100, a specific inhibitor of CXCR4, increased LPS treatment associated mortality. Blocking CXCR4 via chemical or genetic inhibition resulted in a reversion of LPS tolerance, thus further supporting the negative regulatory role of CXCR4 in this inflammatory response. In support of an inhibitory role for CXCR4 in the inflammatory cascade, IL1 transcript levels were elevated in both unstimulated and LPS stimulated zebrafish Odysseus (CXCR4 deficient mutant) larvae. PMID:19110060

  7. Development of a Promising Fish Model (Oryzias melastigma) for Assessing Multiple Responses to Stresses in the Marine Environment

    PubMed Central

    Dong, Sijun; Kang, Mei; Wu, Xinlong; Ye, Ting

    2014-01-01

    With the increasing number of contaminants in the marine environment, various experimental organisms have been “taken into labs” by investigators to find the most suitable environmentally relevant models for toxicity testing. The marine medaka, Oryzias melastigma, has a number of advantages that make it a prime candidate for these tests. Recently, many studies have been conducted on marine medaka, especially in terms of their physiological, biochemical, and molecular responses after exposure to contaminants and other environmental stressors. This review provides a literature survey highlighting the steady increase of ecotoxicological research on marine medaka, summarizes the advantages of using O. melastigma as a tool for toxicological research, and promotes the utilization of this organism in future studies. PMID:24724087

  8. Comparison of Cell and Nuclear Size Difference between Diploid and Induced Triploid in Marine Medaka, Oryzias dancena

    PubMed Central

    Goo, In Bon; Im, Jae Hyun; Gil, Hyun Woo; Lim, Sang Gu; Park, In-Seok

    2015-01-01

    The influence of triploidization on cell and nucleus size characteristics of the same tissues of erythrocyte, retina, kidney, hepatocyte and midgut epithelium in marine medaka, Oryzias dancena has been determined histologically. Induced triploid fish are produced by cold shock treatments. Likewise, the size of horizontal cell nucleus in inner nuclear layer of retina, ganglion cell nucleus in ganglion cell layer of retina, proximal tubule cell of kidney, hepatocytes and nuclear height of midgut epithelium all appear to be significantly larger than diploid (p<0.05). On the other hand, retina thickness is larger in diploid than induced triploid (p<0.05). Induced triploid shows low density of cell number. Results of this study suggest that same characteristics in the induced triploid exhibiting larger cells and nucleus sizes with fewer number of cells than the diploid can be useful criteria for the distinction between diploid and induced triploid, and also the ploidy level in marine medaka. PMID:27004269

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  11. An Inexpensive Method to Simulate a Monohybrid Cross Using Wild-Type Zebrafish ("Danio rerio")

    ERIC Educational Resources Information Center

    Lassiter, Christopher S.

    2010-01-01

    Monohybrid crosses are taught in biology labs across the country using peas and corn. Students studying monohybrid crosses using zebrafish ("Danio rerio") would encounter a new model organism, and those interested in human or veterinary medicine would have increased interest. To this end, our college has implemented a laboratory exercise at the…

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

    SciTech Connect

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

    2012-04-18

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

  13. Characterization of glutathione-S-transferases in zebrafish (Danio rerio).

    PubMed

    Glisic, Branka; Mihaljevic, Ivan; Popovic, Marta; Zaja, Roko; Loncar, Jovica; Fent, Karl; Kovacevic, Radmila; Smital, Tvrtko

    2015-01-01

    Glutathione-S-transferases (GSTs) are one of the key enzymes that mediate phase II of cellular detoxification. The aim of our study was a comprehensive characterization of GSTs in zebrafish (Danio rerio) as an important vertebrate model species frequently used in environmental research. A detailed phylogenetic analysis of GST superfamily revealed 27 zebrafish gst genes. Further insights into the orthology relationships between human and zebrafish GSTs/Gsts were obtained by the conserved synteny analysis. Expression of gst genes in six tissues (liver, kidney, gills, intestine, brain and gonads) of adult male and female zebrafish was determined using qRT-PCR. Functional characterization was performed on 9 cytosolic Gst enzymes after overexpression in E. coli and subsequent protein purification. Enzyme kinetics was measured for GSH and a series of model substrates. Our data revealed ubiquitously high expression of gstp, gstm (except in liver), gstr1, mgst3a and mgst3b, high expression of gsto2 in gills and ovaries, gsta in intestine and testes, gstt1a in liver, and gstz1 in liver, kidney and brain. All zebrafish Gsts catalyzed the conjugation of GSH to model GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and monochlorobimane (MCB), apart from Gsto2 and Gstz1 that catalyzed GSH conjugation to dehydroascorbate (DHA) and dichloroacetic acid (DCA), respectively. Affinity toward CDNB varied from 0.28 mM (Gstp2) to 3.69 mM (Gstm3), while affinity toward MCB was in the range of 5 μM (Gstt1a) to 250 μM (Gstp1). Affinity toward GSH varied from 0.27 mM (Gstz1) to 4.45 mM (Gstt1a). Turnover number for CDNB varied from 5.25s(-1) (Gstt1a) to 112s(-1) (Gstp2). Only Gst Pi enzymes utilized ethacrynic acid (ETA). We suggest that Gstp1, Gstp2, Gstt1a, Gstz1, Gstr1, Mgst3a and Mgst3b have important role in the biotransformation of xenobiotics, while Gst Alpha, Mu, Pi, Zeta and Rho classes are involved in the crucial physiological processes. In summary, this study provides the

  14. Assessment of diclofenac LC50 reference values in juvenile and embryonic stages of the zebrafish (Danio rerio).

    PubMed

    Praskova, E; Voslarova, E; Siroka, Z; Plhalova, L; Macova, S; Marsalek, P; Pistekova, V; Svobodova, Z

    2011-01-01

    The aim of the study was to compare the acute toxicity of diclofenac to juvenile and embryonic stages of the zebrafish (Danio rerio). Acute toxicity tests were performed on the aquarium fish Danio rerio, which is one of the model organisms most commonly used in toxicity testing. The tests were performed using a semi-static method according to OECD guideline No. 203 (Fish, acute toxicity test). Embryo toxicity tests were performed in zebrafish embryos (Danio rerio) in compliance with OECD No. 212 methodology (Fish, short-term toxicity test on embryo and sac-fry stages). The results were subjected to a probit analysis using the EKO-TOX 5.2 programme to determine 96hLC50 and 144hLC50 (median lethal concentration, 50% mortality after a 96 h or 144 h interval, respectively) values of diclofenac. The statistical significance of the difference between LC50 values in juvenile and embryonic stages of Danio rerio was tested using the Mann-Whitney non-parametric test implemented in the Unistat 5.1 programme. The LC50 mean value of diclofenac was 166.6 +/- 9.8 mg/L in juvenile Danio rerio, and 6.11 +/- 2.48 mg/L in embryonic stages of Danio rerio. The study demonstrated a statistically higher sensitivity to diclofenac (P < 0.05) in embryonic stages compared to the juvenile fish.

  15. ASSESSMENT OF THE REPRODUCTIVE AXIS: COMPARING CRITICAL PERIODS OF HORMONE SENSITIVITY.

    EPA Science Inventory

    Japanese medaka (Oryzias latipes) have been developed as a model species to compare the effects of endocrine active chemicals at critical life-stage periods of hormonal sensitivity, specifically as reproductively active adults, during the developmental period of differentiation, ...

  16. ISSUES IN ENDOCRINE DISRUPTION: COMPARING CRITICAL PERIODS OF HORMONE SENSITIVITY

    EPA Science Inventory

    Japanese medaka (Oryzias latipes) have been developed as a model species to compare the effects of endocrine active chemicals at critical life-stage periods of hormonal sensitivity, specifically as reproductively active adults, during the developmental period of differentiation, ...

  17. Toxic Effects of Zinc Chloride on the Bone Development in Danio rerio (Hamilton, 1822)

    PubMed Central

    Salvaggio, Antonio; Marino, Fabio; Albano, Marco; Pecoraro, Roberta; Camiolo, Giuseppina; Tibullo, Daniele; Bramanti, Vincenzo; Lombardo, Bianca M.; Saccone, Salvatore; Mazzei, Veronica; Brundo, Maria V.

    2016-01-01

    The increase of heavy metals in the environment involves a high exposure of aquatic organisms to these pollutants. The present study is planned to investigate the effects of zinc chloride (ZnCl2) on the bone embryonic development of Danio rerio and confirm the use of zebrafish as a model organism to study the teratogenic potential of this pollutant. Zebrafish embryos were exposed to different ZnCl2 concentrations and analyzed by ICP-MS. The skeletal anomalies were evaluated to confocal microscope after staining with calcein solution and RhodZinTM-3,AM. The data show a delay in hatching compared with the controls, malformations in the process of calcification and significant defects in growth. In conclusion, the current work demonstrates for the first time the Zn toxic effects on calcification process and confirm zebrafish (Danio rerio) as suitable alternative vertebrate model to study the causes and the mechanisms of the skeletal malformations. PMID:27199768

  18. Toxic Effects of Zinc Chloride on the Bone Development in Danio rerio (Hamilton, 1822).

    PubMed

    Salvaggio, Antonio; Marino, Fabio; Albano, Marco; Pecoraro, Roberta; Camiolo, Giuseppina; Tibullo, Daniele; Bramanti, Vincenzo; Lombardo, Bianca M; Saccone, Salvatore; Mazzei, Veronica; Brundo, Maria V

    2016-01-01

    The increase of heavy metals in the environment involves a high exposure of aquatic organisms to these pollutants. The present study is planned to investigate the effects of zinc chloride (ZnCl2) on the bone embryonic development of Danio rerio and confirm the use of zebrafish as a model organism to study the teratogenic potential of this pollutant. Zebrafish embryos were exposed to different ZnCl2 concentrations and analyzed by ICP-MS. The skeletal anomalies were evaluated to confocal microscope after staining with calcein solution and RhodZin(TM)-3,AM. The data show a delay in hatching compared with the controls, malformations in the process of calcification and significant defects in growth. In conclusion, the current work demonstrates for the first time the Zn toxic effects on calcification process and confirm zebrafish (Danio rerio) as suitable alternative vertebrate model to study the causes and the mechanisms of the skeletal malformations. PMID:27199768

  19. Global DNA methylation in gonads of adult zebrafish Danio rerio under bisphenol A exposure.

    PubMed

    Liu, Yan; Zhang, Yingying; Tao, Shiyu; Guan, Yongjing; Zhang, Ting; Wang, Zaizhao

    2016-08-01

    Altered DNA methylation is pervasively associated with changes in gene expression and signal transduction after exposure to a wide range of endocrine disrupting chemicals. As a weak estrogenic chemical, bisphenol A (BPA) has been extensively studied for reproductive toxicity. In order to explore the effects of BPA on epigenetic modification in gonads of zebrafish Danio rerio, we measured the global DNA methylation together with the gene expression of DNA methyltransferase (dnmts), glycine N-methyltransferase (gnmt), and ten-eleven translocation (tets) in gonads of D. rerio under BPA exposure by ELISA and quantitative real-time PCR method, respectively. The global level of DNA methylation was significantly decreased in ovaries after exposed to BPA for 7 days, and testes following 35-day exposure. Moreover, the global level of DNA methylation was also significantly reduced in testes after exposed to 15μg/L BPA for 7 days. Besides the alteration of the global level of DNA methylation, varying degrees of transcriptional changes of dnmts, gnmt and tets were detected in gonads of D. rerio under BPA exposure. The present study suggested that BPA might cause the global DNA demethylation in gonads of zebrafish by regulating the transcriptional changes of the DNA methylation/demethylation-associated genes (dnmts, gnmt, and tets). PMID:27101439

  20. Endocrine disrupting effects of domestic wastewater on reproduction, sexual behavior, and gene expression in the brackish medaka Oryzias melastigma.

    PubMed

    Chen, Te-Hao; Chou, Shi-Ming; Tang, Cheng-Hao; Chen, Chia-Yang; Meng, Pei-Jie; Ko, Fung-Chi; Cheng, Jing-O

    2016-05-01

    The objective of this study was to investigate the endocrine disrupting effects of domestic wastewater on fish using the brackish medaka Oryzias melastigma as the animal model. Estuarine water samples were collected from Sihchong Creek and Baoli Creek estuaries, Taiwan, in March of 2012 to assess the whole effluent toxicity (WET) of domestic wastewater produced by the local residents and tourists. Chemical analysis detected various pharmaceuticals and personal care products (PPCPs) in the field water samples. Some of these PPCPs are endocrine disrupting chemicals. In the laboratory-based bioassay, breeding pairs were exposed to the water samples (Sihchong, Baoli, and control) for 21 days. Cumulative number of eggs spawned was significantly higher in the Sihchong group. While fish swimming activity was not affected, sexual behavior of the male fish was significantly induced in both Sihchong and Baoli groups. Male and female gonad histology was not affected. Expression level of biomarker genes CYP1A1, HSP70, and VTG was significantly induced in the Sihchong group. This study indicates that the mixture of contaminants contained in the estuarine water may cause endocrine disrupting effects in fish.

  1. Accumulation of di(2-ethylhexyl) phthalate causes endocrine-disruptive effects in marine medaka (Oryzias melastigma) embryos.

    PubMed

    Ye, Ting; Kang, Mei; Huang, Qiansheng; Fang, Chao; Chen, Yajie; Liu, Liangpo; Dong, Sijun

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is extensively distributed in marine environments. However, limited research on the toxicological and molecular effects of DEHP on marine organisms has been conducted. Our study investigated the accumulation, elimination, and endocrine-disruptive effects of DEHP on embryonic marine medaka (Oryzias melastigma). The medaka embryos were continuously exposed to DEHP (0.01, 0.1, and 1 mg/L) or 17β-estradiol (E2, 0.01 mg/L) until hatching, and the newly hatched larvae were then transferred to clean sea water for 12 days of depuration. DEHP and E2 appeared to have no significant effects on the mortality and hatching rates of medaka embryos, but E2 exposure significantly delayed the hatching. Significantly higher DEHP embryonic burdens were detected in the group treated with higher DEHP (0.1 and 1 mg/L) at 10 dpf (days post fertilization). The recovered larvae showed an elimination tendency of DEHP during the recovery period. DEHP had no significant effects on the transcriptional responses of endocrine-disrupting biomarker genes in the 3-dpf embryos. Treatment with 0.1 and 1 mg/L DEHP elicited a significant induction of transcriptional responses of ER, PPAR, and the CYP19 genes in a concentration-dependent manner at 10 dpf, indicating endocrine disruption may be due to bioaccumulation of DEHP. With the elimination of DEHP during the depuration period, all of the effects on these genes showed no significant effects. However, 0.1 mg/L E2 significantly affected the expression of ER, PPAR, and the CYP19 genes in the exposed embryos at both 3 and 10 dpf and recovered larvae. Therefore, these results demonstrate that accumulation of DEHP caused endocrine disruption in medaka embryos and that recovery in clean sea water may weaken the endocrine-disrupting effects. PMID:25066029

  2. Size-dependent reproductive success of wild zebrafish Danio rerio in the laboratory.

    PubMed

    Uusi-Heikkilä, S; Wolter, C; Meinelt, T; Arlinghaus, R

    2010-08-01

    Size-dependent reproductive success of wild zebrafish Danio rerio was studied under controlled conditions in the laboratory to further understand the influence of spawner body size on reproductive output and egg and larval traits. Three different spawner size categories attained by size-selective harvesting of the F(1)-offspring of wild D. rerio were established and their reproductive performance compared during a 5 day period. As to be expected, large females spawned more frequently and had significantly greater clutch sizes than small females. Contrary to expectations, small females produced larger eggs when measured as egg diameter with similar amounts of yolk compared to eggs spawned by large spawners. Eggs from small fish, however, suffered from higher egg mortality than the eggs of large individuals. Embryos from small-sized spawners also hatched later than offspring from eggs laid by large females. Larval standard length (L(S))-at-hatch did not differ between the size categories, but the offspring of the large fish had significantly larger area-at-hatch and greater yolk-sac volume indicating better condition. Offspring growth rates were generally similar between offspring from all size categories, but they were significantly higher for offspring spawned by small females in terms of L(S) between days 60 and 90 post-fertilization. Despite temporarily higher growth rates among the small fish offspring, the smaller energy reserves at hatching translated into lower condition later in ontogeny. It appeared that the influence of spawner body size on egg and larval traits was relatively pronounced early in development and seemed to remain in terms of condition, but not in growth, after the onset of exogenous feeding. Further studies are needed to explore the mechanisms behind the differences in offspring quality between large- and small-sized spawners by disentangling size-dependent maternal and paternal effects on reproductive variables in D. rerio.

  3. Expression of sclerostin in the developing zebrafish (Danio rerio) brain and skeleton.

    PubMed

    McNulty, Melissa S; Bedell, Victoria M; Greenwood, Tammy M; Craig, Theodore A; Ekker, Stephen C; Kumar, Rajiv

    2012-01-01

    Sclerostin is a highly conserved, secreted, cystine-knot protein which regulates osteoblast function. Humans with mutations in the sclerostin gene (SOST), manifest increased axial and appendicular skeletal bone density with attendant complications. In adult bone, sclerostin is expressed in osteocytes and osteoblasts. Danio rerio sclerostin-like protein is closely related to sea bass sclerostin, and is related to chicken and mammalian sclerostins. Little is known about the expression of sclerostin in early developing skeletal or extra-skeletal tissues. We assessed sclerostin (sost) gene expression in developing zebrafish (D. rerio) embryos with whole mount is situ hybridization methods. The earliest expression of sost mRNA was noted during 12h post-fertilization (hpf). At 15 hpf, sost mRNA was detected in the developing nervous system and in Kupffer's vesicle. At 18, 20 and 22 hpf, expression in rhombic lip precursors was seen. By 24 hpf, expression in the upper and lower rhombic lip and developing spinal cord was noted. Expression in the rhombic lip and spinal cord persisted through 28 hpf and then diminished in intensity through 44 hpf. At 28 hpf, sost expression was noted in developing pharyngeal cartilage; expression in pharyngeal cartilage increased with time. By 48 hpf, sost mRNA was clearly detected in the developing pharyngeal arch cartilage. Sost mRNA was abundantly expressed in the pharyngeal arch cartilage, and in developing pectoral fins, 72, 96 and 120 hpf. Our study is the first detailed analysis of sost gene expression in early metazoan development.

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

    PubMed

    Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P < 0,05) on both concentrations and exposure times were observed in experimental groups. DNA damage was highest at 96 h and 24 h for all BX and BA concentrations, respectively in peripheral blood of D. rerio. For the first time, our study demonstrates the effect of waterborne BA and BX exposure on genotoxicity at the molecular level, which may contribute to understanding the mechanism of boric acid and borax-induced genotoxicity in fish. PMID:26862320

  5. Trophic transfer of amphiphilic polymer coated CdSe/ZnS quantum dots to Danio rerio

    NASA Astrophysics Data System (ADS)

    Lewinski, Nastassja A.; Zhu, Huiguang; Ouyang, Clare R.; Conner, George P.; Wagner, Daniel S.; Colvin, Vicki L.; Drezek, Rebekah A.

    2011-08-01

    To investigate the trophic transfer of nanomaterials along the food chain, we examined the potential trophic transfer and biomagnification of CdSe/ZnS quantum dots (QDs) in a simple freshwater food chain. Our results indicate that QDs can transfer from zooplankton to Danio rerio (zebrafish) by dietary exposure. No significant biomagnification of QDs was observed and the biomagnification factors for both adult and juvenile zebrafish were both less than one (0.04 and 0.004 respectively). The assimilation efficiency was 8% and 4% for adult and juvenile zebrafish respectively. This study is the first to examine the potential food chain transfer and biomagnification of QDs from zooplankton to zebrafish.To investigate the trophic transfer of nanomaterials along the food chain, we examined the potential trophic transfer and biomagnification of CdSe/ZnS quantum dots (QDs) in a simple freshwater food chain. Our results indicate that QDs can transfer from zooplankton to Danio rerio (zebrafish) by dietary exposure. No significant biomagnification of QDs was observed and the biomagnification factors for both adult and juvenile zebrafish were both less than one (0.04 and 0.004 respectively). The assimilation efficiency was 8% and 4% for adult and juvenile zebrafish respectively. This study is the first to examine the potential food chain transfer and biomagnification of QDs from zooplankton to zebrafish. Electronic supplementary information (ESI) available. See DOI: 10.1039/c1nr10319a

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

    PubMed Central

    Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P < 0,05) on both concentrations and exposure times were observed in experimental groups. DNA damage was highest at 96 h and 24 h for all BX and BA concentrations, respectively in peripheral blood of D. rerio. For the first time, our study demonstrates the effect of waterborne BA and BX exposure on genotoxicity at the molecular level, which may contribute to understanding the mechanism of boric acid and borax-induced genotoxicity in fish. PMID:26862320

  7. Effect of glyphosate on the sperm quality of zebrafish Danio rerio.

    PubMed

    Lopes, Fernanda Moreira; Varela Junior, Antonio Sergio; Corcini, Carine Dahl; da Silva, Alessandra Cardoso; Guazzelli, Vitória Gasperin; Tavares, Georgia; da Rosa, Carlos Eduardo

    2014-10-01

    Glyphosate is a systemic, non-selective herbicide widely used in agriculture worldwide. It acts as an inhibitor of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase by interrupting the synthesis of essential aromatic amino acids. This pathway is not present in animals, although some studies have shown that the herbicide glyphosate can affect fish reproduction. In this study, the effect of glyphosate on sperm quality of the fish Danio rerio was investigated after 24 and 96 h of exposure at concentrations of 5mg/L and 10mg/L. The spermatic cell concentration, sperm motility and motility period were measured employing conventional microscopy. The mitochondrial functionality, membrane integrity and DNA integrity were measured by fluorescence microscopy using specific probes. No significant differences in sperm concentration were observed; however, sperm motility and the motility period were reduced after exposure to both glyphosate concentrations during both exposure periods. The mitochondrial functionality and membrane and DNA integrity were also reduced at the highest concentration during both exposure periods. The results showed that glyphosate can induce harmful effects on reproductive parameters in D. rerio and that this change would reduce the fertility rate of these animals. PMID:25089920

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

    PubMed

    Gülsoy, Nagihan; Yavas, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and Olive tail moment. Genotoxicity was found for BA as concentration-dependent and BX as concentration and time dependent manner. In general, significant effects (P < 0,05) on both concentrations and exposure times were observed in experimental groups. DNA damage was highest at 96 h and 24 h for all BX and BA concentrations, respectively in peripheral blood of D. rerio. For the first time, our study demonstrates the effect of waterborne BA and BX exposure on genotoxicity at the molecular level, which may contribute to understanding the mechanism of boric acid and borax-induced genotoxicity in fish.

  9. Characterization, cDNA cloning and expression pattern of relaxin gene during embryogenesis of Danio rerio.

    PubMed

    Fiengo, Marcella; Donizetti, Aldo; del Gaudio, Rosanna; Minucci, Sergio; Aniello, Francesco

    2012-06-01

    We report the identification, the cDNA cloning, the temporal and spatial expression pattern analysis of the rln gene in the zebrafish Danio rerio. The deduced Rln B and A domains show different evolutionary conservation. Rln B domain shows higher similarity when compared to zebrafish and human RLN3 B domain than human RLN1 and RLN2 B domain. Differently, the zebrafish Rln A domain shows relatively low amino acid sequence similarity when compared with the same sequences. The rln gene is transcribed both during embryogenesis and in adult organism, where higher transcript level has been particularly evidenced in the brain. Moreover, we provide the first description of rln spatial expression pattern during embryonic development. In particular, we show restricted transcript localization starting at the pharyngula stage in olfactory placode, branchial arch region, and in a cell cluster near to otic vesicle. In larval stage, new transcription territories have been detected in both neural and non-neural regions. In particular, in the brain, rln expression has been revealed in telencephalic region around anterior commissure, in the preoptic area, and in restricted rombencephalic cell clusters. Expression of rln gene in extra-neural territories has been detected in the pancreatic and thyroid gland regions. Danio rerio rln expression pattern analysis reveals shared features with the mammalian RLN gene, particularly in the brain, where it might have a role in the neurophysiological processes. In addition, expression in the thyroid and pancreas region suggests a function as a paracrine and endocrine hormone.

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

    EPA Science Inventory

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

  11. Uptake of platinum by zebrafish (Danio rerio) and ramshorn snail (Marisa cornuarietis) and resulting effects on early embryogenesis.

    PubMed

    Osterauer, Raphaela; Haus, Nadine; Sures, Bernd; Köhler, Heinz-R

    2009-11-01

    Platinum group elements (PGEs), platinum, palladium and rhodium are widely used in automobile catalytic converters. PGEs are emitted into the environment and enter the aquatic ecosystem via runoff rainwater. The present study investigated the bioavailability of platinum chloride for the zebrafish (Danio rerio) and the ramshorn snail (Marisa cornuarietis) and determined the bioaccumulation rate of platinum. Applying the fish early life stage assay for D. rerio (DarT) and the Marisa embryo toxicity test ("Mariett") for M. cornuarietis, effects of platinum chloride on the embryonic development were investigated. Platinum concentrations tested in this study ranged from environmentally relevant concentrations of 38 ng L(-1) up to a concentration of 74.2 microg L(-1) for D. rerio and of 200 ngL(-1) up to 98.7 microg L(-1) for M. cornuarietis. Platinum was found to be accumulated in both organisms. Bioaccumulation factors (BAFs) were in the range of 5-55 for D. rerio and of 218.4-723.9 for M. cornuarietis, depending on the tested Pt concentrations. During the embryonic development, platinum was shown to alter the heart rate of both organisms already at the lowest tested concentration. At higher concentrations, platinum decelerated the hatching rate of the embryos of both species. Additionally, a retardation of the general development and a loss of weight due to platinum exposure was observed in M. cornuarietis. Results of this study contribute important data on the ecotoxicity of a rarely studied element.

  12. Exposure to DEHP and MEHP from hatching to adulthood causes reproductive dysfunction and endocrine disruption in marine medaka (Oryzias melastigma).

    PubMed

    Ye, Ting; Kang, Mei; Huang, Qiansheng; Fang, Chao; Chen, Yajie; Shen, Heqing; Dong, Sijun

    2014-01-01

    Concern has increased regarding the adverse effects of di-(2-ethylhexyl)-phthalate (DEHP) on reproduction. However, limited information is available on the effects of DEHP in marine organisms. The aim of the present study was to examine whether long-term exposure to DEHP and its active metabolite mono-(2-ethylhexyl)-phthalate (MEHP) disrupts endocrine function in marine medaka (Oryzias melastigma). Marine medaka larvae were exposed to either DEHP (0.1 and 0.5mg/L) or MEHP (0.1 and 0.5mg/L) for 6 months, and the effects on reproduction, sex steroid hormones, liver vitellogenin (VTG), gonad histology and the expression of genes involved in the hypothalamic-pituitary-gonad (HPG) axis were investigated. Exposure to DEHP, but not MEHP, from hatching to adulthood accelerated the start of spawning and decreased the egg production of exposed females. Moreover, exposure to both DEHP and MEHP resulted in a reduction in the fertilization rate of oocytes spawned by untreated females paired with treated males. A significant increase in plasma 17β-estradiol (E2) along with a significant decrease in testosterone (T)/E2 ratios was observed in males, which was accompanied by the upregulation of ldlr, star, cyp17a1, 17βhsd, and cyp19a transcription in the testis. Increased concentrations of T and E2 were observed in females, which was consistent with the upregulation of ldlr. The expression of brain gnrhr2, fshβ, cyp19b and steroid hormone receptor genes also corresponded well with hormonal and reproductive changes. The liver VTG level was significantly increased after DEHP and MEHP exposure in males. DEHP induced histological changes in the testes and ovaries: the testes displayed a reduced number of spermatozoa, and the ovaries displayed an increased number of atretic follicles. In addition, the tissue concentrations of MEHP, MEHHP and MEOHP in DEHP-exposed groups were much higher than those in MEHP-exposed groups, and there were no dose- or sex-specific effects. Thus, DEHP

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

    EPA Science Inventory

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

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

    PubMed

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

    2016-02-01

    Understanding the nanomaterial potential to the food conversion of two food chain levels is important in the ecosystem assessment as manufactured nanomaterials are being released into the environment. In this investigation, the food conversion from Daphnia magna (D. magna) (prey) to Danio rerio (D. rerio) (predator) was used as the study object of aqueous stable fullerene nanocrystals (nC60). Accumulated nC60 of D. magna was determined as the nominal initial exposure concentration for D. rerio. The results of 21-d dietary exposure experiment demonstrate that nC60 in D. magna decreased the body weight growths and condition factors of D. rerio, and reduced the food conversion ratio by 20% (from D. magna to D. rerio). Further, the experiments present that nC60 decrease three digestive enzymes activities of trypsinase, lipase, and amylase by 30, 29, and 55% in vivo, and by 60, 90, and 42% in vitro, respectively. Both in vivo and in vitro experiments indicated that nC60 was involved with the decrements of digestive enzymes activities. These decrements in digestive enzymes activities may be due to the deactivation caused by the adsorption of nC60 particles onto the surface or active center of digestive enzymes. Sum up, these results not only describe the nC60 deleterious effects on the food conversion from D. magna to D. rerio, but also provide some information regarding a probable food conversion inhibition mechanism of nC60. PMID:26688252

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

    PubMed

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

    2016-02-01

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

  16. Genetic variation in strains of zebrafish (Danio rerio) and the implications for ecotoxicology studies.

    PubMed

    Coe, T S; Hamilton, P B; Griffiths, A M; Hodgson, D J; Wahab, M A; Tyler, C R

    2009-01-01

    There is substantial evidence that genetic variation, at both the level of the individual and population, has a significant effect on behaviour, fitness and response to toxicants. Using DNA microsatellites, we examined the genetic variation in samples of several commonly used laboratory strains of zebrafish, Danio rerio, a model species in toxicological studies. We compared the genetic variation to that found in a sample of wild fish from Bangladesh. Our findings show that the wild fish were significantly more variable than the laboratory strains for several measures of genetic variability, including allelic richness and expected heterozygosity. This lack of variation should be given due consideration for any study which attempts to extrapolate the results of ecotoxicological laboratory tests to wild populations.

  17. Identification of Novel Transcribed Regions in Zebrafish (Danio rerio) Using RNA-Sequencing

    PubMed Central

    Wang, Jingwen; Vesterlund, Liselotte; Kere, Juha; Jiao, Hong

    2016-01-01

    Zebrafish (Danio rerio) has emerged as a model organism to investigate vertebrate development and human genetic diseases. However, the zebrafish genome annotation is still ongoing and incomplete, and there are still new gene transcripts to be found. With the introduction of massive parallel sequencing, whole transcriptome studies became possible. In the present study, we aimed to discover novel transcribed regions (NTRs) using developmental transcriptome data from RNA sequencing. In order to achieve this, we developed an in-house bioinformatics pipeline for NTR discovery. Using the pipeline, we detected 152 putative NTRs that at the time of discovery were not annotated in Ensembl and NCBI gene database. Four randomly selected NTRs were successfully validated using RT-PCR, and expression profiles of 10 randomly selected NTRs were evaluated using qRT-PCR. The identification of these 152 NTRs provide new information for zebrafish genome annotation as well as new candidates for studies of zebrafish gene function. PMID:27462902

  18. A Fluorescence-Based Assay for Proteinuria Screening in Larval Zebrafish (Danio rerio).

    PubMed

    Hanke, Nils; King, Benjamin L; Vaske, Bernhard; Haller, Hermann; Schiffer, Mario

    2015-10-01

    Analysis of genes compromising the glomerular filtration barrier in rodent models using transgenic or knockdown approaches is time- and resource-consuming and often leads to unsatisfactory results. Therefore, it would be beneficial to have a selection tool indicating that your gene of interest is in fact associated with proteinuria. Zebrafish (Danio rerio) is a rapid screening tool to study effects in glomerular filtration barrier integrity after genetic manipulation. We use either injection of high-molecular-weight dextrans or a transgenic fluorescent fish line [Tg(l-fabp:DBP:EGFP)] expressing a vitamin D-binding protein fused with eGFP for indirect detection of proteinuria. A loss of high-molecular-weight proteins from the circulation of the fish into the urine can be identified by monitoring fluorescence intensity in the zebrafish eye. Paired with an optimized analysis method, this assay provides an effective screening solution to detect filtration barrier damage with proteinuria before moving to a mammalian system.

  19. The genetic basis of cardiac function: dissection by zebrafish (Danio rerio) screens.

    PubMed Central

    Warren, K S; Wu, J C; Pinet, F; Fishman, M C

    2000-01-01

    The vertebrate heart differs from chordate ancestors both structurally and functionally. Genetic units of form, termed 'modules', are identifiable by mutation, both in zebrafish and mouse, and correspond to features recently acquired in evolution, such as the ventricular chamber or endothelial lining of the vessels and heart. Zebrafish (Danio rerio) genetic screens have provided a reasonably inclusive set of such genes. Normal cardiac function may also be disrupted by single-gene mutations in zebrafish. Individual mutations may perturb contractility or rhythm generation. The zebrafish mutations which principally disturb cardiac contractility fall into two broad phenotypic categories, 'dilated' and 'hypertrophic'. Interestingly, these correspond to the two primary types of heart failure in humans. These disorders of early cardiac function provide candidate genes to be examined in complex human heart diseases, including arrhythmias and heart failure. PMID:11128987

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

    PubMed Central

    Kovrižnych, Jevgenij A.; Zeljenková, Dagmar; Rollerová, Eva; Szabová, Elena

    2014-01-01

    Nickel oxide in the form of nanoparticles (NiO NPs) is extensively used in different industrial branches. In a test on adult zebrafish, the acute toxicity of NiO NPs was shown to be low, however longlasting contact with this compound can lead to its accumulation in the tissues and to increased toxicity. In this work we determined the 30-day toxicity of NiO NPs using a static test for zebrafish Danio rerio. We found the 30-day LC50 value to be 45.0 mg/L, LC100 (minimum concentration causing 100% mortality) was 100.0 mg/L, and LC0 (maximum concentration causing no mortality) was 6.25 mg/L for adult individuals of zebrafish. Considering a broad use of Ni in the industry, NiO NPs chronic toxicity may have a negative impact on the population of aquatic organisms and on food web dynamics in aquatic systems. PMID:26038672

  1. Influence of kinship and MHC class II genotype on visual traits in zebrafish larvae (Danio rerio).

    PubMed

    Hinz, Cornelia; Gebhardt, Katharina; Hartmann, Alexander K; Sigman, Lauren; Gerlach, Gabriele

    2012-01-01

    Kin recognition can drive kin selection and the evolution of social behaviour. In zebrafish (Danio rerio, Hamilton 1822), kin recognition is based on olfactory and visual imprinting processes. If larvae are exposed to visual and chemical cues of kin at day 5 and 6 post fertilization they will recognize kin throughout life, while exposure to non-kin fails to trigger any recognition. Chemical imprinting signals are transcribed by polymorphic genes of the major histocompatibility complex (MHC) code; however, the underlying mechanism for visual imprinting remains unclear. Here we provide evidence for the existence of family-specific differences in morphometry and pigmentation pattern of six day old zebrafish larvae. While rump, tail and body pigmentation were dependent on relatedness, iris pigmentation and morphometry were also influenced by MHC class II genotype. Our study revealed that the MHC not only influences the chemical signature of individuals, but also their visual appearance. PMID:23251449

  2. In vivo analysis of effects of venom from the jellyfish Chrysaora sp. in zebrafish (Danio rerio).

    PubMed

    Becerra-Amezcua, Mayra P; Guerrero-Legarreta, Isabel; González-Márquez, Humberto; Guzmán-García, Xochitl

    2016-04-01

    The jellyfishes of the genus Chrysaora are present in all of the world's oceans, but the toxicity of their venoms has not yet been thoroughly characterized. The zebrafish as a toxicology model can be used for general toxicity testing of drugs and the investigation of toxicological mechanisms. The aim of this study was to evaluate the effect of crude venom from jellyfish Chrysaora sp., a species of jellyfish observed in the tropical lagoons of the Gulf of Mexico, on the zebrafish Danio rerio. Juvenile zebrafish were injected with different concentrations of venom from Chrysaora sp. via intraperitoneal and subcutaneous injections. The effects of the venom were determined by histopathological analysis and through the measurement of hemolytic and phospholipase A2 activities. The crude venom was examined by SDS-PAGE. The effect of sublethal concentrations of crude venom from Chrysaora sp. on D. rerio was hemorrhaging in the eyes, while the histopathological analysis demonstrated that the primary organs targeted were the pseudobranch, which displayed hyperemia, and the gill, which displayed hyperplasia and hypertrophy. The blood analysis exhibited hemolysis, nuclear abnormalities, and echinocytes by the action of phospholipase A2, which was determined to have 596 units of activity/mg of protein in the venom. The crude venom has proteins with molecular weights ranging from 250 to 6 kDa, with more density in the bands corresponding to 70, 20 and 15 kDa. The venom of Chysaora sp. caused disturbances in circulation associated with vascular dilation due to the localized release of inflammatory mediators. The hemolysis of erythrocytes was caused by the action of phospholipase A2. These findings not only provide an excellent study model but also have a great pharmacological potential for designing new drugs and for the elucidation of the mechanisms of action of and treatment against stings. PMID:26876134

  3. Avoidance response of Danio rerio to a fungicide in a linear contamination gradient.

    PubMed

    Araújo, Cristiano V M; Shinn, Cândida; Mendes, Lucas B; Delello-Schneider, Danieli; Sanchez, André L; Espíndola, Evaldo L G

    2014-06-15

    The present study examines the ability of juvenile Danio rerio to avoid pyrimethanil-contaminated water. An avoidance assay system was used with a contamination gradient formed by seven compartments, through which the fish could move and choose the preferred compartment(s). Additionally, the influence of fish movements in promoting the mixing between compartments and thus disruption of the gradient over time was also examined by testing sodium chloride (NaCl) at sublethal concentrations. Samples with pyrimethanil were obtained from the commercial formulation Mythos®, which was applied to mesocosm systems. Samples of the pyrimethanil-contaminated mesocosms water were collected and a series of seven concentrations (0.2 to 1.4mgL(-1) plus a control) diluted with reference (uncontaminated) mesocosm water were added to the system to form the gradient. After 4h exposure, fish avoidance in the three highest pyrimethanil concentrations ranged from 29 to 66%. The 4h-AC50 (concentration at which 50% of the fish avoided pyrimethanil after 4h exposure) was 1.10 (confidence interval: 1.07 to 1.12)mgL(-1). However, the avoidance pattern after 12h was strongly reduced and it was not possible to calculate the AC50. This is explained by the results of the NaCl experiment, which showed that the movement of fish in the system accelerates the mixing of the solutions between compartments. As pyrimethanil can trigger avoidance response in D. rerio, this fungicide, even at non-lethal concentrations, could be considered an environmental disturber.

  4. In vivo analysis of effects of venom from the jellyfish Chrysaora sp. in zebrafish (Danio rerio).

    PubMed

    Becerra-Amezcua, Mayra P; Guerrero-Legarreta, Isabel; González-Márquez, Humberto; Guzmán-García, Xochitl

    2016-04-01

    The jellyfishes of the genus Chrysaora are present in all of the world's oceans, but the toxicity of their venoms has not yet been thoroughly characterized. The zebrafish as a toxicology model can be used for general toxicity testing of drugs and the investigation of toxicological mechanisms. The aim of this study was to evaluate the effect of crude venom from jellyfish Chrysaora sp., a species of jellyfish observed in the tropical lagoons of the Gulf of Mexico, on the zebrafish Danio rerio. Juvenile zebrafish were injected with different concentrations of venom from Chrysaora sp. via intraperitoneal and subcutaneous injections. The effects of the venom were determined by histopathological analysis and through the measurement of hemolytic and phospholipase A2 activities. The crude venom was examined by SDS-PAGE. The effect of sublethal concentrations of crude venom from Chrysaora sp. on D. rerio was hemorrhaging in the eyes, while the histopathological analysis demonstrated that the primary organs targeted were the pseudobranch, which displayed hyperemia, and the gill, which displayed hyperplasia and hypertrophy. The blood analysis exhibited hemolysis, nuclear abnormalities, and echinocytes by the action of phospholipase A2, which was determined to have 596 units of activity/mg of protein in the venom. The crude venom has proteins with molecular weights ranging from 250 to 6 kDa, with more density in the bands corresponding to 70, 20 and 15 kDa. The venom of Chysaora sp. caused disturbances in circulation associated with vascular dilation due to the localized release of inflammatory mediators. The hemolysis of erythrocytes was caused by the action of phospholipase A2. These findings not only provide an excellent study model but also have a great pharmacological potential for designing new drugs and for the elucidation of the mechanisms of action of and treatment against stings.

  5. A Subtracted cDNA Library from the Zebrafish (Danio rerio) Embryonic Inner Ear

    PubMed Central

    Coimbra, Roney S.; Weil, Dominique; Brottier, Phillipe; Blanchard, Stéphane; Levi, Michael; Hardelin, Jean-Pierre; Weissenbach, Jean; Petit, Christine

    2002-01-01

    A database was built that consists of 4694 sequence contigs of ∼18,000 reads of cDNAs isolated from the microdissected otocysts of zebrafish embryos at 20–30 hour postfertilization, following subtraction with a pool of liver cDNAs from adult fish. These sequences were compared with those of public databanks. Significant similarity were recorded and organized in a relational database at http://www.genoscope.cns.fr/zie. A first group of 2067 sequences correspond to 1428 known zebrafish genes or ESTs present in the Danio rerio section of UniGene. A second group of 302 sequences encode putative proteins that showed significant similarity (50%–100%) with 302 nonzebrafish proteins in the nr databank, a public databank containing an exhaustive nonredundant collection of protein sequences from different species (ftp://ftp.ncbi.nlm.nih.gov/blast/db/nr). The remaining 2325 (49.5%) sequence contigs or singletons showed no significant similarity with sequences available in public databanks. Several genes known to be expressed in the developing inner ear were represented in the present database, in particular genes involved in hair cell differentiation or innervation The occurrence of these genes validates the outcome of this study as the first collection of ESTs preferentially expressed in the zebrafish inner ear during the period of hair cell differentiation and neuroblast delamination from the otic vesicle epithelium. Novel zebrafish genes also involved in these processes are thus likely to be represented among the sequences obtained herein, for which no homology was found in the D. rerio section of UniGene. [The sequence data from this study have been submitted to EMBL under accession nos. AL714032–AL731531]. PMID:12045154

  6. In vivo effects of 17-β-estradiol on plasma immunoglobulin levels and leukocyte density in zebrafish Danio rerio

    NASA Astrophysics Data System (ADS)

    Li, Lei; Zhang, Shicui; Tong, Zhou; Liu, Jia

    2010-05-01

    Estradiol, or 17-β-estradiol (E2), the most potent naturally occurring estrogen, is involved in the hormone-immune system interaction in both mammals and fish. However, in vivo studies are largely limited, and little is known about whether E2 exerts similar effects on both female and male zebrafish ( Danio rerio). Here, we show exposure of both sexes of D. rerio to 20 nmol/L E2 resulted in a significant increase in Vg1 expression, but caused little damage to the hepatocytes, suggesting that this is the optimum E2 concentration. Also, exposure to 20 nmol/L E2 for 20 days caused a marked increase in plasma IgM levels, but had little influence on the peripheral leukocyte density, providing the first evidence of a hormone-immune system interaction in this species.

  7. Effect of hunger level and time of day on boldness and aggression in the zebrafish Danio rerio.

    PubMed

    Ariyomo, T O; Watt, P J

    2015-06-01

    The effect of two environmental variables, hunger level (fed or not fed before behavioural assays) and time of day (morning or afternoon), on the boldness and aggressiveness of male and female zebrafish Danio rerio, was tested. The results showed that neither hunger level nor time of testing influenced boldness in males and females, but hunger level significantly affected aggression in females when compared with males.

  8. Effects of subchronic exposure of diclofenac on growth, histopathological changes, and oxidative stress in zebrafish (Danio rerio).

    PubMed

    Praskova, Eva; Plhalova, Lucie; Chromcova, Lucie; Stepanova, Stanislava; Bedanova, Iveta; Blahova, Jana; Hostovsky, Martin; Skoric, Misa; Maršálek, Petr; Voslarova, Eva; Svobodova, Zdenka

    2014-01-01

    The aim of this study was to investigate effects of subchronic exposure to sublethal levels of diclofenac on growth, oxidative stress, and histopathological changes in Danio rerio. The juvenile growth tests were performed on Danio rerio according to OECD method number 215. Fish at the age of 20 days were exposed to the diclofenac environmental concentration commonly detected in the Czech rivers (0.02 mg L(-1)) and the range of sublethal concentrations of diclofenac (5, 15, 30, and 60 mg L(-1)) for 28 days. A significant decrease (P < 0.01) in the fish growth caused by diclofenac was observed in the concentrations of 30 and 60 mg L(-1). The identified value of LOEC (lowest observed effect concentration) was 15 mg L(-1) of diclofenac and NOEC (no observed effect concentration) value was 5 mg L(-1) of diclofenac. We did not find histopathological changes and changes of selected parameters of oxidative stress (glutathione S-transferase, glutathione reductase) in tested fish. The environmental concentration of diclofenac in Czech rivers did not have any effect on growth, selected oxidative stress parameters (glutathione S-transferase, glutathione reductase), or histopathological changes in Danio rerio but it could have an influence on lipid peroxidation.

  9. Impairment of the immune system in GH-overexpressing transgenic zebrafish (Danio rerio).

    PubMed

    Batista, Carolina R; Figueiredo, Márcio A; Almeida, Daniela V; Romano, Luis A; Marins, Luis F

    2014-02-01

    Growth hormone (GH) is an important regulator of immune functions in vertebrates, and it has been intensively reported a series of stimulatory actions of this hormone over on the immune system. Within aquaculture, overexpression of GH has been considered a promising alternative for promoting higher growth rates in organisms of commercial interest. Considering the various pleiotropic effects of GH, there are still few studies that aim to understand the consequences of the excess of GH on the physiological systems. In this context, our goal was to present the effects of the overexpression of GH on immune parameters using a model of zebrafish (Danio rerio) that overexpress this hormone. The results showed that GH transgenic zebrafish had 100% of mortality when immunosuppressed with dexamethasone, revealing a prior weakening of the immune system in this lineage. Morphometric analysis of thymus and head kidney revealed a reduction in the area of these structures in transgenic zebrafish. Moreover, the phenotypic expression of CD3 and CD4 thymocytes was also depreciated in transgenic zebrafish. Furthermore, a decrease was noted in the expression of genes RAG-1 (60%), IKAROS (50%), IL-1β (55%), CD4 (60%) and CD247 (40%), indicating that development parameters, of innate and acquired immunity, are being harmed. Based on these results, it can be concluded that the excess of GH impairs the immune functions in GH transgenic zebrafish, indicating that the maintenance of normal levels of this hormone is essential for the functioning of immunological activities.

  10. Pharmacological study of the light/dark preference test in zebrafish (Danio rerio): Waterborne administration.

    PubMed

    Magno, Lílian Danielle Paiva; Fontes, Aldo; Gonçalves, Beatriz Maria Necy; Gouveia, Amauri

    2015-08-01

    Anxiety is a complex disorder; thus, its mechanisms remain unclear. Zebrafish (Danio rerio) are a promising pharmacological model for anxiety research. Light/dark preference test is a behaviorally validated measure of anxiety in zebrafish; however, it requires pharmacological validation. We sought to evaluate the sensitivity of the light/dark preference test in adult zebrafish by immersing them in drug solutions containing clonazepam, buspirone, imipramine, fluoxetine, paroxetine, haloperidol, risperidone, propranolol, or ethanol. The time spent in the dark environment, the latency time to first crossing, and the number of midline crossings were analyzed. Intermediate concentrations of clonazepam administered for 600s decreased the time spent in the dark and increased locomotor activity. Buspirone reduced motor activity. Imipramine and fluoxetine increased time spent in the dark and the first latency, and decreased the number of alternations. Paroxetine did not alter the time in the dark; however, it increased the first latency time and decreased locomotor activity. Haloperidol decreased the time spent in the dark at low concentrations. Risperidone and propranolol did not change any parameters. Ethanol reduced the time spent in the dark and increased the number of crossings at intermediate concentrations. These results corroborate the previous work using intraperitoneal drug administration in zebrafish and rodents, suggesting that water drug delivery in zebrafish can effectively be used as an animal anxiety model.

  11. Uptake and biotransformation of structurally diverse brominated flame retardants in zebrafish (Danio rerio) after dietary exposure.

    PubMed

    Nyholm, Jenny Rattfelt; Norman, Anna; Norrgren, Leif; Haglund, Peter; Andersson, Patrik L

    2009-05-01

    Zebrafish (Danio rerio) were fed a diet containing a mixture of 11 structurally diverse brominated flame retardants (BFRs) at nominal concentrations of either 1 or 100 nmol/g for up to 42 d, followed by an elimination period of 14 d. Uptake rates and elimination constants for five of the BFRs were calculated from measurements of their concentrations in the male fish during the exposure and elimination phases. Observed uptake efficiencies were highest for 2,4,4'-tribromodiphenyl ether (BDE 28) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) and were lowest for decabromodiphenyl ether (BDE 209). Estimated half-lives for TBECH and 2,4,6-tribromophenol were short (<2 d). Four BFR metabolites were identified in the fish: 2,2',3,4',5',6-Hexabromodiphenyl ether (BDE 149), 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE 154), 2,4,6-tribromoanisole, and 1,2,4,5-hexabromobenzene. These metabolites were still present in the zebrafish after the 14-d elimination period. No relationship between the BFR concentrations in the zebrafish and their log octanol-water partition coefficient (Kow) values was found. Generally, low tendencies to bioaccumulate were observed for perbrominated and hydroxylated compounds. The observed accumulation of BFR metabolites in fish, however, shows that low concentration of a BFR does not provide, in isolation, a sound indication that the BFR poses low risks. PMID:19049262

  12. Evaluation of oxidative stress and genetic damage caused by detergents in the zebrafish Danio rerio (Cyprinidae).

    PubMed

    Sobrino-Figueroa, Alma S

    2013-08-01

    Detergents are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the toxicity (lipid peroxidation) and genotoxic (frequency of DNA strand breaks) effects were evaluated in the gill and liver tissues of zebrafish (Danio rerio), exposed for 16days to a sublethal concentration (CL10) of two commercial detergents (laundry and dishwasher use) and an anionic surfactant: alkyl lauryl sulfonate (LAS). The results demonstrated high toxicity with dishwasher detergent, resulting in high lipid peroxidation levels (MDA malondialdehyde evaluation). No differences in MDA concentrations were found among fish exposed to laundry detergent and organisms exposed to LAS. In the genetic damage evaluation, significant differences in the number of cells with DNA strand breaks (comets) were observed: the fish exposed to dishwasher detergent presented the highest number of damaged cells (79%), in comparison with those exposed to other products (laundry and LAS) and the control group (8% damaged cells). The toxicity of dishwasher detergent (biological detergent containing enzymes and perfume) was higher than the value observed with LAS. Laundry detergent does not contain enzymes or perfume and its toxicity was similar to LAS. Since detergents are complex mixtures of different substances, in which additive and/or synergistic effects may occur, the deleterious effect caused by the dishwasher detergent was probably due to the combined effects of the ingredients of detergent.

  13. Effect of rearing temperatures during embryonic development on the phenotypic sex in zebrafish (Danio rerio).

    PubMed

    Abozaid, H; Wessels, S; Hörstgen-Schwark, G

    2011-01-01

    In zebrafish, Danio rerio, a polygenic pattern of sex determination or a female heterogamety with possible influences of environmental factors is assumed. The present study focuses on the effects of an elevated water temperature (35° C) during the embryonic development on sex determination in zebrafish. Eggs derived from 3 golden females were fertilized by the same mitotic gynogenetic male and exposed to a water temperature of 35° C, applied from 5 to 10 h post fertilization (hpf), from 5 to 24 hpf, and from 5 to 48 hpf, which correspond to the following developmental stages: gastrula, gastrula to segmentation, and gastrula to pharyngula stage, respectively. Hatching and survival rates decreased with increasing exposure to high water temperatures. Reductions in the hatching and survival rates were not responsible for differences in sex ratios. Accordingly, exposition of the fertilized eggs to a high temperature (35° C) leads to an increase of the male proportion from 22.0% in the controls to a balanced sex ratio (48.3, 47.5, and 52.6%) in the gastrula, segmentation, and pharyngula groups, respectively. These results prove the possibility to change the pathway of sexual determination during early embryonic stages in zebrafish by exposure to a high water temperature.

  14. The secreted factor Ag1 missing in higher vertebrates regulates fins regeneration in Danio rerio

    PubMed Central

    Ivanova, Anastasiya S.; Shandarin, Igor N.; Ermakova, Galina V.; Minin, Andrey A.; Tereshina, Maria B.; Zaraisky, Andrey G.

    2015-01-01

    Agr family includes three groups of genes, Ag1, Agr2 and Agr3, which encode the thioredoxin domain-containing secreted proteins and have been shown recently to participate in regeneration of the amputated body appendages in amphibians. By contrast, higher vertebrates have only Agr2 and Agr3, but lack Ag1, and have low ability to regenerate the body appendages. Thus, one may hypothesize that loss of Ag1 in evolution could be an important event that led to a decline of the regenerative capacity in higher vertebrates. To test this, we have studied now the expression and role of Ag1 in the regeneration of fins of a representative of another large group of lower vertebrates, the fish Danio rerio. As a result, we have demonstrated that amputation of the Danio fins, like amputation of the body appendages in amphibians, elicits an increase of Ag1 expression in cells of the stump. Furthermore, down-regulation of DAg1 by injections of Vivo-morpholino antisense oligonucleotides resulted in a retardation of the fin regeneration. These data are in a good agreement with the assumption that the loss of Ag1 in higher vertebrates ancestors could lead to the reduction of the regenerative capacity in their modern descendants. PMID:25630240

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

    PubMed

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

    2016-03-01

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

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

    PubMed Central

    Bilberg, Katrine; Hovgaard, Mads Bruun; Besenbacher, Flemming; Baatrup, Erik

    2012-01-01

    The influence of water chemistry on characterised polyvinyl pyrrolidone- (PVP-) coated silver nanoparticles (81 nm) was investigated. NaCl solution series of 100–800 mg L−1 lead to initial and temporal increase in nanoparticles size, but agglomeration was limited. pH variation (5–8) had only minor influence on the hydrodynamic particle size. Acute toxicity of nanosivler to zebrafish (Danio rerio) was investigated in a 48-hour static renewal study and compared with the toxicity of silver ions (AgNO3). The nanosilver and silver ion 48-hour median lethal concentration (LC50) values were 84 μg L−1 and 25 μg L−1, respectively. To investigate exposure-related stress, the fish behaviour was observed visually after 0, 3, 6, 12, 24, 27, 30, and 48 hours of both nanosilver and ionic silver treatments. These observations revealed increased rate of operculum movement and surface respiration after nanosilver exposure, suggesting respiratory toxicity. The present study demonstrates that silver nanoparticles are lethal to zebrafish. PMID:22174711

  17. The Effects of Salicylic Acid on Juvenile Zebrafish Danio rerio Under Flow-Through Conditions.

    PubMed

    Zivna, Dana; Blahova, Jana; Siroka, Zuzana; Plhalova, Lucie; Marsalek, Petr; Doubkova, Veronika; Zelinska, Gabriela; Vecerek, Vladimir; Tichy, Frantisek; Sehonova, Pavla; Svobodova, Zdenka

    2016-09-01

    The aquatic environment is becoming increasingly contaminated with pharmaceuticals. Salicylic acid (SA), which can be used individually or appear as a degradation product of the widely used acetylsalicylic acid was chosen for testing. Juvenile zebrafish Danio rerio were subjected to OECD test No. 215 (fish, juvenile growth test) with salicylic acid concentrations of 0.004; 0.04; 0.4; 4 and 40 mg/L. Specific growth rate (SGR), histological changes, and parameters of oxidative stress were evaluated. SA had no effects on histological changes, SGR, glutathione reductase, and lipid peroxidation. Increased catalytic activity of GPx was found at 0.04 mg/L compared to control, increased catalytic activity of catalase was found at 0.04 and 4 mg/L compared to control, and increased catalytic activity of glutathione-S-transferase was found at 0.004 and 0.04 mg/L compared to control (P < 0.05). Juvenile zebrafish turned out to be relatively insensitive to both environmentally relevant (0.004 mg/L) and higher concentrations of salicylic acid. PMID:27385367

  18. Evaluation of oxidative stress and genetic damage caused by detergents in the zebrafish Danio rerio (Cyprinidae).

    PubMed

    Sobrino-Figueroa, Alma S

    2013-08-01

    Detergents are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the toxicity (lipid peroxidation) and genotoxic (frequency of DNA strand breaks) effects were evaluated in the gill and liver tissues of zebrafish (Danio rerio), exposed for 16days to a sublethal concentration (CL10) of two commercial detergents (laundry and dishwasher use) and an anionic surfactant: alkyl lauryl sulfonate (LAS). The results demonstrated high toxicity with dishwasher detergent, resulting in high lipid peroxidation levels (MDA malondialdehyde evaluation). No differences in MDA concentrations were found among fish exposed to laundry detergent and organisms exposed to LAS. In the genetic damage evaluation, significant differences in the number of cells with DNA strand breaks (comets) were observed: the fish exposed to dishwasher detergent presented the highest number of damaged cells (79%), in comparison with those exposed to other products (laundry and LAS) and the control group (8% damaged cells). The toxicity of dishwasher detergent (biological detergent containing enzymes and perfume) was higher than the value observed with LAS. Laundry detergent does not contain enzymes or perfume and its toxicity was similar to LAS. Since detergents are complex mixtures of different substances, in which additive and/or synergistic effects may occur, the deleterious effect caused by the dishwasher detergent was probably due to the combined effects of the ingredients of detergent. PMID:23542746

  19. Hormetic Responses of Food-Supplied Pcb 31 to Zebrafish (Danio Rerio) Growth

    PubMed Central

    Hashmi, Muhammad Zaffar; Naveedullah; Yu, Chunna

    2015-01-01

    Hormesis is commonly defined as a beneficial or stimulatory effect caused by exposure to low doses of a chemical known to be toxic at high doses. Hormetic responses of food-supplied PCB 31 (2, 4’, 5-Trichlorobiphenyl) was studied by using zebrafish (Danio rerio) growth as an end point. The results in general followed the hormesis hypothesis, PCB 31 at lower concentrations (0.042 μg/g and 0.084 μg/g) exhibited beneficial effects on the growth of zebrafish by weight and length while higher concentrations (10μg/g and 20μg/g) revealed inhibitory effects. The magnitude of stimulatory responses of zebrafish growth by weight and length at lower concentrations (0.01-0.084 μg/g) on days 14 and 21 were in the range 9.09-18.18%; 10-38.09% and 4-14.4%; 6.25-10.93%, respectively as compared to control. Growth and conditions indices also suggested that the zebrafish was healthier at lower concentrations as compared to those at higher concentrations. The results of the present study will elaborate fish toxicological evaluation regarding the hormetic model. PMID:26673801

  20. Ultraviolet B radiation alters movement and thermal selection of zebrafish (Danio rerio).

    PubMed

    Seebacher, Frank; Kazerouni, Ensiyeh Ghanizadeh; Franklin, Craig E

    2016-08-01

    Temperature and ultraviolet B (UV-B) interact in causing cellular damage and impairing locomotor performance. Here, we test the hypothesis that movement and thermal selection of zebrafish (Danio rerio) change in the presence of UV-B, and in particular, that fish which were chronically exposed to UV-B avoid high and low temperature extremes to maximize activities of antioxidant enzymes. Fish chronically (two to three weeks) exposed to UV-B had increased reactive oxygen species (ROS)-induced damage to proteins and membranes, and reduced swimming performance at high (more than 26°C) temperatures. In an open field arena with a thermal gradient, chronically exposed fish avoided high and low temperature extremes compared with control fish. Additionally, both control and chronically exposed fish showed slower voluntary swimming speeds in the presence of UV-B. We suggest that in the presence of UV-B fish may reduce muscular activity to minimize intrinsic ROS production. Our data show that the interaction between UV-B and temperature determines movement and microhabitat selection of fish, which is therefore of ecological importance particularly in anthropogenically modified environments. PMID:27531156

  1. Effects of butachlor on reproduction and hormone levels in adult zebrafish (Danio rerio).

    PubMed

    Chang, Juhua; Liu, Shaoying; Zhou, Shengli; Wang, Minghua; Zhu, Guonian

    2013-01-01

    Butachlor, a chloracetamide herbicide, is widely used in China. In the present study, paired adult male and female zebrafish (Danio rerio) were exposed to various concentrations of butachlor (0, 25, 50 and 100 μg/L) for 30 days, and the effects on reproduction and endocrine disruption were evaluated using fecundity, condition factor (CF), gonadosomatic index (GSI), liver somatic index (LSI), plasma vitellogenin (VTG), sex steroids and thyroid hormone levels as endpoints. Our results showed that the mean fecundity rates were significantly decreased at 50 and 100 μg/L butachlor during the 30-day exposure period. At the end of the exposure period, no significant changes were observed in CF and LSI in both females and males, while GSI was significantly reduced in males at 50 and 100 μg/L butachlor. At 100 μg/L butachlor, plasma testosterone (T) and 17β-estradiol (E2) levels were significantly decreased in females, while plasma VTG level was significantly increased in males. Plasma thyroxine (T4) and triiodothyronine (T3) levels were significantly increased at 50 and 100 μg/L butachlor in males, and at 100 μg/L in females. This work demonstrated that butachlor adversely affected the normal reproductive success of zebrafish, and disrupted the thyroid and sex steroid endocrine systems, which provides the basis for the estimated ecological risk during butachlor exposure.

  2. Behavioral Plasticity in Response to Environmental Manipulation among Zebrafish (Danio rerio) Populations

    PubMed Central

    Bhat, Anuradha; Greulich, Melissa M.; Martins, Emília P.

    2015-01-01

    Plastic responses can have adaptive significance for organisms occurring in unpredictable environments, migratory species and organisms occupying novel environments. Zebrafish (Danio rerio) occur in a wide range of habitats and environments that fluctuate frequently across seasons and habitats. We expect wild populations of fish to be behaviorally more flexible than fish reared in conventional laboratory and hatchery environments. We measured three behavioral traits among 2 wild (U and PN) and 1 laboratory bred (SH) zebrafish populations in four environments differing in water flow and vegetation regimes. We found that the degree of plasticity varied with the type of behavior and also among populations. In general, vegetation increased aggression and water flow decreased latency to feed after a disturbance, but the patterns were population dependent. For example, while wild U fish fed more readily after a disturbance in vegetated and/or flowing habitats, fish from the wild PN population and lab-reared SH strain showed little variation in foraging across different environmental conditions. Zebrafish from all the three populations were more aggressive when tested in an arena with vegetation. In contrast, while there was an inter- population difference in shoaling distances, variation in shoaling distance across environmental conditions within populations was not significant. These results suggest that both foraging and aggression in zebrafish are more plastic and influenced by immediate context than is shoaling distance, which may have a stronger genetic basis. Our findings point to different underlying mechanisms influencing the expression of these traits and warrants further investigations. PMID:25927838

  3. A Fluorescence-Based Assay for Proteinuria Screening in Larval Zebrafish (Danio rerio).

    PubMed

    Hanke, Nils; King, Benjamin L; Vaske, Bernhard; Haller, Hermann; Schiffer, Mario

    2015-10-01

    Analysis of genes compromising the glomerular filtration barrier in rodent models using transgenic or knockdown approaches is time- and resource-consuming and often leads to unsatisfactory results. Therefore, it would be beneficial to have a selection tool indicating that your gene of interest is in fact associated with proteinuria. Zebrafish (Danio rerio) is a rapid screening tool to study effects in glomerular filtration barrier integrity after genetic manipulation. We use either injection of high-molecular-weight dextrans or a transgenic fluorescent fish line [Tg(l-fabp:DBP:EGFP)] expressing a vitamin D-binding protein fused with eGFP for indirect detection of proteinuria. A loss of high-molecular-weight proteins from the circulation of the fish into the urine can be identified by monitoring fluorescence intensity in the zebrafish eye. Paired with an optimized analysis method, this assay provides an effective screening solution to detect filtration barrier damage with proteinuria before moving to a mammalian system. PMID:26125680

  4. Toxicological Assessment of Trace β-Diketone Antibiotic Mixtures on Zebrafish (Danio rerio) by Proteomic Analysis

    PubMed Central

    Yin, Xiaohan; Wang, Huili; Zhang, Yuna; Dahlgren, Randy A.; Zhang, Hongqin; Shi, Mengru; Gao, Ming; Wang, Xuedong

    2014-01-01

    β-Diketone antibiotics (DKAs) can produce chronic toxicity in aquatic ecosystems due to their pseudo-persistent in the environment. In this study, after long-term DKA exposure to zebrafish (Danio rerio), 47 protein spots had greater than 2-fold differential expression as compared to the control; there were 26 positive proteins with 14 up-regulated and 12 down-regulated. The main functions of the differentially expressed proteins were related to signal transduction mechanisms and the cytoskeleton. Of the 26 target genes, 11 genes were consistent between their transcriptional and translational levels. Low dose DKA exposure (4.69 and 9.38 mg/L) stimulated spontaneous movement in zebrafish. Changes in both creatine kinase activity and creatine concentration showed a similar trend to zebrafish activity. There was no obvious change in SV-BA after DKA exposure, while a reduction of heart rate was concomitant with increasing DKA concentrations. DKAs also induced severe histopathological changes in zebrafish heart tissue, such as dissolution of cristae and vacuolation of mitochondria. These results demonstrated that trace-level DKA exposure affects a variety of cellular and biological processes in zebrafish. PMID:25062015

  5. Subacute microcystin-LR exposure alters the metabolism of thyroid hormones in juvenile zebrafish (Danio Rerio).

    PubMed

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-02-01

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs. PMID:25647779

  6. Circadian clock mediates light/dark preference in zebrafish (Danio rerio).

    PubMed

    Wang, Ju; Liu, Changhong; Ma, Fei; Chen, Wei; Liu, Jian; Hu, Bing; Zheng, Lei

    2014-04-01

    Zebrafish (Danio rerio) has been a widely used vertebrate animal model in developmental biology and behavioral neuroscience, but knowledge about some of its basic behaviors, for example, light/dark preference, is still controversial. Appropriate preference for light or dark environments can be crucial for an animal's survival, so we hypothesize that zebrafish may have its light/dark preference varied with the circadian clock. In this present work, we tested the hypothesis by recording the light/dark preference in a two-compartment tank continuously for over 60 h. We found that the light avoidance of fish generally increases with time from morning (8:00am) to midnight (2:00am), and then decreases with time from midnight (2:00am) to morning (8:00am), exhibiting a clear circadian-like trend in the light/dark preference. As melatonin can mediate circadian clock output and promote sleep in zebrafish, by adding extra melatonin at around 9:00am on the third day, the mean proportion of time fish spent in the dark area was increased significantly. Our results demonstrate that the circadian clock plays a significant role in regulating the light/dark preference in zebrafish, which provides valuable insights into understanding the metabolism mechanism underlying the neurobehavior, and facilitate further studies related to the neurobiology of normal and pathological behavior.

  7. The influence of probiotics on zebrafish Danio rerio innate immunity and hepatic stress.

    PubMed

    Gioacchini, Giorgia; Giorgini, Elisabetta; Olivotto, Ike; Maradonna, Francesca; Merrifield, Daniel L; Carnevali, Oliana

    2014-04-01

    In this study, the effects of probiotic administration on zebrafish Danio rerio intestinal innate immunity and hepatic stress were evaluated. Zebrafish adults were treated for 10 days with the probiotic Lactobacillus rhamnosus IMC 501(®). To assess the effects at the molecular level, the mRNA levels of genes involved in the innate immune system, stress response, oxidative stress, and apoptosis were quantified by real-time polymerase chain reaction. An increase of biomarkers related to innate immune responses was observed in intestinal tissue from the probiotic-treated fish compared with the control fish. In addition, a decrease in the abundance of stress and apoptotic-related genes was observed in the liver of the probiotic-fed fish. Finally, imaging Fourier transform infrared analysis was conducted on liver sections and the data obtained confirmed that probiotic administration decreased oxidative stress levels, decreased DNA damage, and increased lipid saturation levels. Overall, the results show that probiotic administration may enhance zebrafish welfare by modulating the innate immune response and improving hepatic stress tolerance.

  8. Temporal dynamics of oocyte growth and vitellogenin gene expression in zebrafish (Danio rerio).

    PubMed

    Connolly, Michelle H; Dutkosky, Rachel M; Heah, Tze P; Sayler, Gary S; Henry, Theodore B

    2014-04-01

    Little is known about how hepatic vitellogenin gene (vtg) expression relates to oogenesis in fish, especially among fractional spawners. The objective of this study was to relate hepatic vtg 1A/B expression to stage-specific oocyte development in zebrafish (Danio rerio), an asynchronous spawning fish. Liver samples were collected at seven time points postspawning (1-32 days) and fish were preserved for subsequent histological analyses. Relative vtg 1A/B expression among liver samples was quantified by reverse transcription-quantitative PCR and oogenesis was evaluated following standard hematoxylin and eosin staining of serial ovarian sections. Histological analyses indicate that a subset of previtellogenic oocytes (stages 1-2) transitioned into postvitellogenic oocytes (stages 3-4) within 4 days (96 h) postspawning. By 8 days postspawning (192 h), the majority of the ovary was occupied by mature (stage 4) oocytes, a trend that continued through 32 days postspawning. Hepatic vtg 1A/B gene expression was upregulated 3.89-fold 1-h postspawning relative to the average gene expression across all time points, but was not correlated to stage-specific oogenesis. Follicular atresia among fish sampled 32 days postspawning highlights the importance of regular spawning in zebrafish and suggests that the event of spawning itself may be integral to the regulation of oocyte development.

  9. A retrospective study of the prevalence and classification of intestinal neoplasia in zebrafish (Danio rerio).

    PubMed

    Paquette, Colleen E; Kent, Michael L; Buchner, Cari; Tanguay, Robert L; Guillemin, Karen; Mason, Timothy J; Peterson, Tracy S

    2013-06-01

    For over a decade, spontaneous intestinal neoplasia has been observed in zebrafish (Danio rerio) submitted to the ZIRC (Zebrafish International Resource Center) diagnostic service. In addition, zebrafish displayed preneoplastic intestinal changes including hyperplasia, dysplasia, and enteritis. A total of 195 zebrafish, representing 2% of the total fish submitted to the service, were diagnosed with these lesions. Neoplastic changes were classified either as adenocarcinoma or small cell carcinoma, with a few exceptions (carcinoma not otherwise specified, tubular adenoma, and tubulovillous adenoma). Tumor prevalence appeared similarly distributed between sexes and generally occurred in zebrafish greater than 1 year of age, although neoplastic changes were observed in fish 6 months of age. Eleven lines displayed these preneoplastic and neoplastic changes, including wild-types and mutants. Affected zebrafish originated from 18 facilities, but the majority of fish were from a single zebrafish research facility (hereafter referred to as the primary facility) that has submitted numerous samples to the ZIRC diagnostic service. Zebrafish from the primary facility submitted as normal sentinel fish demonstrate that these lesions are most often subclinical. Fish fed the diet from the primary facility and held at another location did not develop intestinal lesions, indicating that diet is not the etiologic agent.

  10. Alcohol-induced morphological deficits in the development of octavolateral organs of the zebrafish (Danio rerio).

    PubMed

    Zamora, Lilliann Y; Lu, Zhongmin

    2013-03-01

    Prenatal alcohol exposure is known to have many profound detrimental effects on human fetal development (fetal alcohol spectrum disorders), which may manifest as lifelong disabilities. However, how alcohol affects the auditory/vestibular system is still largely unknown. This is the first study to investigate morphological effects of alcohol on the developing octavolateral system (the inner ear and lateral line) using the zebrafish, Danio rerio. Zebrafish embryos of 2 hours post fertilization (hpf) were treated in 2% alcohol for 48 hours and screened at 72 hpf for morphological defects of the inner ear and lateral line. Octavolateral organs from both alcohol-treated and control zebrafish were examined using light, confocal, and scanning electron microscopy. We observed several otolith phenotypes for alcohol-treated zebrafish including zero, one, two abnormal, two normal, and multiple otoliths. Results of this study show that alcohol treatment during early development impairs the inner ear (smaller ear, abnormal otoliths, and fewer sensory hair cells) and the lateral line (smaller neuromasts, fewer neuromasts and hair cells per neuromast, and shorter kinocilia of hair cells). Early embryonic alcohol exposure may also result in defects in hearing, balance, and hydrodynamic function of zebrafish.

  11. Effects of glyphosate and its formulation, roundup, on reproduction in zebrafish (Danio rerio).

    PubMed

    Uren Webster, Tamsyn M; Laing, Lauren V; Florance, Hannah; Santos, Eduarda M

    2014-01-21

    Roundup and its active ingredient glyphosate are among the most widely used herbicides worldwide and may contaminate surface waters. Research suggests both Roundup and glyphosate induce oxidative stress in fish and may also cause reproductive toxicity in mammalian systems. We aimed to investigate the reproductive effects of Roundup and glyphosate in fish and the potential associated mechanisms of toxicity. To do this, we conducted a 21-day exposure of breeding zebrafish (Danio rerio) to 0.01, 0.5, and 10 mg/L (glyphosate acid equivalent) Roundup and 10 mg/L glyphosate. 10 mg/L glyphosate reduced egg production but not fertilization rate in breeding colonies. Both 10 mg/L Roundup and glyphosate increased early stage embryo mortalities and premature hatching. However, exposure during embryogenesis alone did not increase embryo mortality, suggesting that this effect was caused primarily by exposure during gametogenesis. Transcript profiling of the gonads revealed 10 mg/L Roundup and glyphosate induced changes in the expression of cyp19a1 and esr1 in the ovary and hsd3b2, cat, and sod1 in the testis. Our results demonstrate that these chemicals cause reproductive toxicity in zebrafish, although only at high concentrations unlikely to occur in the environment, and likely mechanisms of toxicity include disruption of the steroidogenic biosynthesis pathway and oxidative stress.

  12. Subacute microcystin-LR exposure alters the metabolism of thyroid hormones in juvenile zebrafish (Danio Rerio).

    PubMed

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-01-30

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs.

  13. Combined toxicity of silica nanoparticles and methylmercury on cardiovascular system in zebrafish (Danio rerio) embryos.

    PubMed

    Duan, Junchao; Hu, Hejing; Li, Qiuling; Jiang, Lizhen; Zou, Yang; Wang, Yapei; Sun, Zhiwei

    2016-06-01

    This study was to investigate the combined toxicity of silica nanoparticles (SiNPs) and methylmercury (MeHg) on cardiovascular system in zebrafish (Danio rerio) embryos. Ultraviolet absorption analysis showed that the co-exposure system had high absorption and stability. The dosages used in this study were based on the NOAEL level. Zebrafish embryos exposed to the co-exposure of SiNPs and MeHg did not show any cardiovascular malformation or atrioventricular block, but had an inhibition effect on bradycardia. Using o-Dianisidine for erythrocyte staining, the cardiac output of zebrafish embryos was decreased gradually in SiNPs, MeHg, co-exposure groups, respectively. Co-exposure of SiNPs and MeHg enhanced the vascular endothelial damage in Tg(fli-1:EGFP) transgenic zebrafish line. Moreover, the co-exposure significantly activated the oxidative stress and inflammatory response in neutrophils-specific Tg(mpo:GFP) transgenic zebrafish line. This study suggested that the combined toxic effects of SiNPs and MeHg on cardiovascular system had more severe toxicity than the single exposure alone.

  14. The zebrafish anatomy and stage ontologies: representing the anatomy and development of Danio rerio

    PubMed Central

    2014-01-01

    Background The Zebrafish Anatomy Ontology (ZFA) is an OBO Foundry ontology that is used in conjunction with the Zebrafish Stage Ontology (ZFS) to describe the gross and cellular anatomy and development of the zebrafish, Danio rerio, from single cell zygote to adult. The zebrafish model organism database (ZFIN) uses the ZFA and ZFS to annotate phenotype and gene expression data from the primary literature and from contributed data sets. Results The ZFA models anatomy and development with a subclass hierarchy, a partonomy, and a developmental hierarchy and with relationships to the ZFS that define the stages during which each anatomical entity exists. The ZFA and ZFS are developed utilizing OBO Foundry principles to ensure orthogonality, accessibility, and interoperability. The ZFA has 2860 classes representing a diversity of anatomical structures from different anatomical systems and from different stages of development. Conclusions The ZFA describes zebrafish anatomy and development semantically for the purposes of annotating gene expression and anatomical phenotypes. The ontology and the data have been used by other resources to perform cross-species queries of gene expression and phenotype data, providing insights into genetic relationships, morphological evolution, and models of human disease. PMID:24568621

  15. Effects of glyphosate and its formulation, roundup, on reproduction in zebrafish (Danio rerio).

    PubMed

    Uren Webster, Tamsyn M; Laing, Lauren V; Florance, Hannah; Santos, Eduarda M

    2014-01-21

    Roundup and its active ingredient glyphosate are among the most widely used herbicides worldwide and may contaminate surface waters. Research suggests both Roundup and glyphosate induce oxidative stress in fish and may also cause reproductive toxicity in mammalian systems. We aimed to investigate the reproductive effects of Roundup and glyphosate in fish and the potential associated mechanisms of toxicity. To do this, we conducted a 21-day exposure of breeding zebrafish (Danio rerio) to 0.01, 0.5, and 10 mg/L (glyphosate acid equivalent) Roundup and 10 mg/L glyphosate. 10 mg/L glyphosate reduced egg production but not fertilization rate in breeding colonies. Both 10 mg/L Roundup and glyphosate increased early stage embryo mortalities and premature hatching. However, exposure during embryogenesis alone did not increase embryo mortality, suggesting that this effect was caused primarily by exposure during gametogenesis. Transcript profiling of the gonads revealed 10 mg/L Roundup and glyphosate induced changes in the expression of cyp19a1 and esr1 in the ovary and hsd3b2, cat, and sod1 in the testis. Our results demonstrate that these chemicals cause reproductive toxicity in zebrafish, although only at high concentrations unlikely to occur in the environment, and likely mechanisms of toxicity include disruption of the steroidogenic biosynthesis pathway and oxidative stress. PMID:24364672

  16. The role of hydrogen sulphide in the control of breathing in hypoxic zebrafish (Danio rerio)

    PubMed Central

    Porteus, Cosima S; Abdallah, Sara J; Pollack, Jacob; Kumai, Yusuke; Kwong, Raymond W M; Yew, Hong M; Milsom, William K; Perry, Steve F

    2014-01-01

    The current study investigated the role of hydrogen sulphide (H2S) in oxygen sensing, intracellular signalling and promotion of ventilatory responses to hypoxia in adult and larval zebrafish (Danio rerio). Both larval and adult zebrafish exhibited a dose-dependent increase in ventilation to sodium sulphide (Na2S), an H2S donor. In vertebrates, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are enzymes that catalyse the endogenous production of H2S. In adult zebrafish, inhibition of both CBS and CSE with aminooxyacetate (AOA) and propargyl glycine (PPG) blunted or abolished the hypoxic hyperventilation, and the addition of Na2S to the water partially rescued the effects of inhibiting endogenous H2S production. In zebrafish larvae (4 days post-fertilization), gene knockdown of either CBS or CSE using morpholinos attenuated the hypoxic ventilatory response. Furthermore, the intracellular calcium concentration of isolated neuroepithelial cells (NECs), which are putative oxygen chemoreceptors, increased significantly when these cells were exposed to 50 μm Na2S, supporting a role for H2S in Ca2+-evoked neurotransmitter release in these cells. Finally, immunohistochemical labelling showed that NECs dissociated from adult gill contained CBS and CSE, whereas cutaneous NECs in larval zebrafish expressed only CSE. Taken together, these data show that H2S can be produced in the putative oxygen-sensing cells of zebrafish, the NECs, in which it appears to play a pivotal role in promoting the hypoxic ventilatory response. PMID:24756639

  17. Danio rerio: the Janus of the bone from embryo to scale

    PubMed Central

    Mariotti, Massimo; Carnovali, Marta; Banfi, Giuseppe

    2015-01-01

    Summary Danio rerio (zebrafish), like the Roman god Janus, is an old animal model which is recently emerged and looks to the future with an increasing scientific success. Unlike other traditional animal models, zebrafish represents a versatile way to approach the study of the skeleton. Transparency of the larval stage, genetic manipulability and unique anatomical structures (scales) makes zebrafish a powerful and versatile instrument to investigate the bone tissue in terms of structure and function. Like Janus, zebrafish offers two different faces, or better, two models in one animal: larval and adult stage. The embryo can be used to isolate new genes involved in osteogenesis by large-scale mutagenesis screenings. The behavior of bone cells and genes in osteogenesis can be investigate by using transgenic lines, vital dyes, mutants and traditional molecular biology techniques. The adult zebrafish represents an important resource to study the pathways related to the bone metabolism and turnover. In particular, the properties of the caudal fin allow to study mechanisms of bone regeneration and reparation whereas the elasmoid scale represents an unique tool to investigate the bone metabolism under physiological or pathological conditions. PMID:26604948

  18. Bis-GMA affects craniofacial development in zebrafish embryos (Danio rerio).

    PubMed

    Kramer, Alexander G; Vuthiganon, Jompobe; Lassiter, Christopher S

    2016-04-01

    Estrogen is a steroid hormone that is vital in vertebrate development and plays a role in a variety of developmental processes including cartilage and craniofacial formation. The effects of estrogen can be mimicked by other compounds found in the environment known as xenoestrogens. Bisphenol-A (BPA) is a known xenoestrogen and is combined with glycidyl methacrylate to make Bisphenol A glycidyl methacrylate (Bis-GMA), a major component in dental resin based composites (RBCs). Bis-GMA based RBCs can release their components into the saliva and bloodstream. Exposure to 1μM and 10μM Bis-GMA in Danio rerio embryos results in increased mortality of approximately 30% and 45% respectively. Changes to gross morphology, specifically craniofacial abnormalities, were seen at concentrations as low as 10nM. While the molecular pathways of Bis-GMA effects have not been studied extensively, more is known about one of the components, BPA. Further research of Bis-GMA could lead to a better understanding of xenoestrogenic activity resulting in improved public and environmental health. PMID:26994444

  19. Behavioral and proteomic analysis of stress response in zebrafish (Danio rerio).

    PubMed

    Magdeldin, Sameh; Blaser, Rachel E; Yamamoto, Tadashi; Yates, John R

    2015-02-01

    The purpose of this study is to determine the behavioral and proteomic consequences of shock-induced stress in zebrafish (Danio rerio) as a vertebrate model. Here we describe the behavioral effects of exposure to predictable and unpredictable electric shock, together with quantitative tandem mass tag isobaric labeling workflow to detect altered protein candidates in response to shock exposure. Behavioral results demonstrate a hyperactivity response to electric shock and a suppression of activity to a stimulus predicting shock. On the basis of the quantitative changes in protein abundance following shock exposure, eight proteins were significantly up-regulated (HADHB, hspa8, hspa5, actb1, mych4, atp2a1, zgc:86709, and zgc:86725). These proteins contribute crucially in catalytic activities, stress response, cation transport, and motor activities. This behavioral proteomic driven study clearly showed that besides the rapid induction of heat shock proteins, other catalytic enzymes and cation transporters were rapidly elevated as a mechanism to counteract oxidative stress conditions resulting from elevated fear/anxiety levels.

  20. Roles of selenoprotein antioxidant protection in zebrafish, Danio rerio, subjected to dietary oxidative stress.

    PubMed

    Betancor, M B; Almaida-Pagán, P F; Sprague, M; Hernández, A; Tocher, D R

    2015-06-01

    In vertebrates, selenium (Se) is an essential micronutrient for vertebrates that is involved in antioxidant protection and thyroid hormone regulation among other roles and functions through its incorporation into proteins, the selenoproteins. Long-chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are essential nutrients for fish although high dietary levels may lead to increased oxidative stress due to the high degree of unsaturation. The present study investigated the effects of Se supplementation on zebrafish, Danio rerio, oxidative status together with selenoprotein expression profiles when subjected to a high-DHA diet. Fish were fed for 8 weeks with one of the four experimental diets, containing high or low DHA in combination with or without organic Se (7 mg/kg). Fish performance, Se content, fatty acid composition and TBARS of zebrafish were determined, as well as gene expression of selected selenoproteins in liver and muscle. The Se levels in whole fish reflected dietary content. High dietary DHA increased oxidative stress as indicated by reduced growth and high TBARS content, although Se supplementation reduced oxidation. The expression patterns of selenoproteins varied between liver and muscle with only deiodinase type II displaying a transcriptional response when high dietary Se was supplied. High dietary DHA decreased selenoprotein W expression in muscle and sps2 expression in liver regardless of the dietary Se content. These data suggest that oxidative stress protection associated with a high dietary intake of Se may not be solely mediated by transcriptional changes in teleost selenoprotein expression.

  1. Modulatory effects of dopamine receptors on associative learning performance in zebrafish (Danio rerio).

    PubMed

    Naderi, Mohammad; Jamwal, Ankur; Chivers, Douglas P; Niyogi, Som

    2016-04-15

    The zebrafish (Danio rerio) has been shown to be an insatiable rival for mammalian model organisms, in many research areas including behavioral neuroscience. Despite a growing body of evidence on successful performance of zebrafish in learning paradigms, little progress has been made toward elucidating the role of neuromodulatory systems in regulation of cognitive functions in this species. Here, we investigated the modulatory effect of dopamine, one of the major neurotransmitters of importance in the brain, on cognitive performance of zebrafish. To this end, a plus maze associative learning paradigm was employed where fish trained to associate a conditioned visual stimulus with the sight of conspecifics as the rewarding unconditioned stimulus. Experimental fish were exposed to dopaminergic agonists (SKF-38393 and quinpirole) and antagonists (SCH-23390 and eticlopride) immediately before training, after training, and just before probe. Pre- and post-training administration of SKF-38393 and SCH-23390 enhanced learning and memory performance of zebrafish in the maze but not when given immediately before the probe trial. Quinpirole also enhanced probe trial performance when administered immediately before training and before the probe but not when given after training. Furthermore, fish that received eticlopride before training, after training or before the probe showed impairment in associative learning performance. Taken together, our results shed first light on modulatory role of dopamine receptors in different aspects of learning and memory in zebrafish. PMID:26801827

  2. 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.

  3. OCCURRENCE OF A MYXOZOAN PARASITE MYXIDIUM STREISINGERI N. SP. IN LABORATORY ZEBRAFISH DANIO RERIO

    PubMed Central

    Whipps, Christopher M.; Murray, Katrina N.; Kent, Michael L.

    2015-01-01

    Over several years of screening diagnostic cases, the Zebrafish International Resource Center Health Services have encountered a myxozoan parasite of the ducts associated with the kidney in zebrafish Danio rerio from and average of 21% of facilities submitting specimens over 5 yr. The parasite is coelozoic and is associated with no appreciable histological changes. Plasmodia bear ovoid spores with 3 sutural ridges. Spores are consistent with the genus Myxidium, but are distinct from any known species, and are thus described as Myxidium streisingeri n. sp. Phylogenetically, this parasite is a member of the polyphyletic urinary bladder clade, which is consistent with the site of infection. The common occurrence of a myxozoan in this closed husbandry system is unexpected because these parasites are known to have complex life cycles, alternating between a vertebrate and invertebrate host. It may be that biofilters provide habitat for suitable invertebrate hosts or perhaps M. streisingeri n. sp. can be transmitted directly. Future control of this parasite in zebrafish research laboratories depends on a better understanding of this life cycle. PMID:25277837

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

    USGS Publications Warehouse

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

    2009-01-01

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

  5. Behavioral and biochemical adjustments of the zebrafish Danio rerio exposed to the β-blocker propranolol.

    PubMed

    Mitchell, Kimberly M; Moon, Thomas W

    2016-09-01

    Propranolol (PROP) is a β-blocker prescribed mainly to treat human cardiovascular diseases and as a result of its wide usage and persistence, it is reported in aquatic environments. This study examined whether PROP alters developmental patterns and catecholamine (CA)-regulated processes in the zebrafish (Danio rerio) and if exposure during early life alters the stress response and behaviors of adults. The calculated 48h larva LC50 was 21.6mg/L, well above reported environmental levels (0.01-0.59μg/L). Stressed and PROP-exposed adult zebrafish had reduced testosterone and estradiol levels and exhibited behaviors indicating less anxiety than control fish. Furthermore, adults previously PROP-exposed as embryos/larvae had decreased growth in terms of body length and mass. Finally, these adults showed increased cholesterol and a dose-dependent decrease in testosterone levels compared with unexposed zebrafish. Thus PROP-exposure of zebrafish embryos/larvae alters developmental patterns and CA-regulated processes that may affect normal behaviors and responses to stressors, and at least some of these changes persist in the adult zebrafish. PMID:26520238

  6. X-RAY STRUCTURE OF DANIO RERIO SECRETAGOGIN, A HEXA-EF-HAND CALCIUM SENSOR

    PubMed Central

    Bitto, Eduard; Bingman, Craig A.; Bittova, Lenka; Frederick, Ronnie O.; Fox, Brian G.; Phillips, George N.

    2009-01-01

    Many essential physiological processes are regulated by the modulation of calcium concentration in the cell. The EF-hand proteins represent a superfamily of calcium-binding proteins involved in calcium signaling and homeostasis. Secretagogin is a hexa-EF-hand protein that is highly expressed in pancreatic islet of Langerhans and neuroendocrine cells and may play a role in the trafficking of secretory granules. We present the X-ray structure of Danio rerio secretagogin, which is 73% identical to human secretagogin, in calcium-free form at 2.1-Å resolution. Secretagogin consists of the three globular domains each of which contains a pair of EF-hand motifs. The domains are arranged into a V-shaped molecule with a distinct groove formed at the interface of the domains. Comparison of the secretagogin structure with the solution structure of calcium-loaded calbindin D28K revealed a striking difference in the spatial arrangement of their domains, which involves approximately a 180-degree rotation of the first globular domain with respect to the module formed by the remaining domains. PMID:19241471

  7. Alcohol-Induced Morphological Deficits in the Development of Octavolateral Organs of the Zebrafish (Danio rerio)

    PubMed Central

    Zamora, Lilliann Y.

    2013-01-01

    Abstract Prenatal alcohol exposure is known to have many profound detrimental effects on human fetal development (fetal alcohol spectrum disorders), which may manifest as lifelong disabilities. However, how alcohol affects the auditory/vestibular system is still largely unknown. This is the first study to investigate morphological effects of alcohol on the developing octavolateral system (the inner ear and lateral line) using the zebrafish, Danio rerio. Zebrafish embryos of 2 hours post fertilization (hpf) were treated in 2% alcohol for 48 hours and screened at 72 hpf for morphological defects of the inner ear and lateral line. Octavolateral organs from both alcohol-treated and control zebrafish were examined using light, confocal, and scanning electron microscopy. We observed several otolith phenotypes for alcohol-treated zebrafish including zero, one, two abnormal, two normal, and multiple otoliths. Results of this study show that alcohol treatment during early development impairs the inner ear (smaller ear, abnormal otoliths, and fewer sensory hair cells) and the lateral line (smaller neuromasts, fewer neuromasts and hair cells per neuromast, and shorter kinocilia of hair cells). Early embryonic alcohol exposure may also result in defects in hearing, balance, and hydrodynamic function of zebrafish. PMID:23461415

  8. Immunohistochemical Characterization of Intestinal Neoplasia in Zebrafish (Danio rerio) Indicates Epithelial Origin

    PubMed Central

    Paquette, Colleen E.; Kent, Michael L.; Peterson, Tracy S.; Wang, Rong; Dashwood, Roderick H.; Löhr, Christiane V.

    2015-01-01

    Spontaneous neoplasia of the intestinal tract in sentinel and moribund zebrafish (Danio rerio) is common in some zebrafish facilities. We previously classified these tumors as adenocarcinoma, small-cell carcinoma, or carcinoma otherwise unspecified based on histomorphologic characteristics. Based on histological presentation, the primary differential diagnosis for the intestinal carcinomas was tumor of neuroendocrine cells (e.g., carcinoids). To further characterize the phenotype of the neoplastic cells, select tissue sections were stained with a panel of antibodies directed toward human epithelial (Cytokeratin Wide Spectrum Screening [WSS], AE1/AE3) or neuroendocrine (S100, chromogranin A) markers. We also investigated antibody specificity by Western blot analysis, using a human cell line and zebrafish tissues. Nine of the intestinal neoplasms (64%) stained for AE1/AE3, seven (50%) also stained for WSS. None of the intestinal neoplastic cells were stained for chromogranin A or S100. Endocrine cells of the pituitary gland and neurons and axons of peripheral nerves and ganglia stained for Chromogranin A, whereas perineural and periaxonal cells of peripheral intestinal ganglia, and glial and ependymal cells of the brain stained for S100. Immunohistochemistry for cytokeratins confirmed the majority of intestinal neoplasms in this cohort of zebrafish as carcinomas. PMID:26503773

  9. Fin-mutant female zebrafish (Danio rerio) exhibit differences in association preferences for male fin length

    PubMed Central

    Gumm, Jennifer M.; Snekser, Jennifer L.; Iovine, M. Kathryn

    2009-01-01

    Females often choose to associate with males that have exaggerated traits. In fishes, this may reflect an overall preference for larger size in a potential mate. Female zebrafish (Danio rerio) prefer males with larger bodies but not longer fins. The availability of mutant and transgenic strains of zebrafish make this a unique model system in which to study the role of phenotypic variation in social and sexual behavior. We used mutant strains of zebrafish with truncated (short fin) and exaggerated (long fin) fins to further examine female preferences for fin length in dichotomous association tests. Wild type females showed no preferences between wild type males and short fin mutant males or between wild type males and long fin mutant males. short fin females also showed no preference for short fin males or wild type males while long fin females preferred to associate with long fin males over wild type males. These results suggest that the single gene long fin mutation that results in altered fin morphological may also be involved in a related female association preference. PMID:18848866

  10. Subacute Microcystin-LR Exposure Alters the Metabolism of Thyroid Hormones in Juvenile Zebrafish (Danio Rerio)

    PubMed Central

    Liu, Zidong; Tang, Rong; Li, Dapeng; Hu, Qing; Wang, Ying

    2015-01-01

    Microcystin-LR (MC-LR) has been detected extensively in the aquatic environment and has the potential to disturb the thyroid endocrine system. However, limited information is available on the effects of subacute MC-LR exposure on fish thyroid hormone (TH) metabolism. In the present study, juvenile zebrafish (Danio rerio) were exposed to MC-LR at environmentally relevant concentrations (0, 1, 5, and 25 μg/L) for 28 days. Whole-body TH content and thyroid follicle histology were used as direct endpoints to assess thyroid disruption. The activities of iodothyronine deiodinases (IDs) and the transcription of selected genes associated with TH synthesis were also investigated to study the underlying mechanisms of endocrine disruption. Exposure of zebrafish to MC-LR significantly increased whole-body thyroxine (T4) content but decreased whole-body triiodothyronine (T3) content. We also observed hypertrophy and hyperplasia of the thyroid follicle epithelial cells, as well as up-regulation of corticotropin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroid peroxidase (TPO), and transthyretin (TTR) genes. The decreases in ID1 and ID2 activities coupled with an increase in ID3 activity were observed in MC-LR treatment groups. These results demonstrate that exposure to MC-LR at environmental concentrations results in the disturbance of TH homeostasis by disrupting the synthesis and conversion of THs. PMID:25647779

  11. The Effects of Salicylic Acid on Juvenile Zebrafish Danio rerio Under Flow-Through Conditions.

    PubMed

    Zivna, Dana; Blahova, Jana; Siroka, Zuzana; Plhalova, Lucie; Marsalek, Petr; Doubkova, Veronika; Zelinska, Gabriela; Vecerek, Vladimir; Tichy, Frantisek; Sehonova, Pavla; Svobodova, Zdenka

    2016-09-01

    The aquatic environment is becoming increasingly contaminated with pharmaceuticals. Salicylic acid (SA), which can be used individually or appear as a degradation product of the widely used acetylsalicylic acid was chosen for testing. Juvenile zebrafish Danio rerio were subjected to OECD test No. 215 (fish, juvenile growth test) with salicylic acid concentrations of 0.004; 0.04; 0.4; 4 and 40 mg/L. Specific growth rate (SGR), histological changes, and parameters of oxidative stress were evaluated. SA had no effects on histological changes, SGR, glutathione reductase, and lipid peroxidation. Increased catalytic activity of GPx was found at 0.04 mg/L compared to control, increased catalytic activity of catalase was found at 0.04 and 4 mg/L compared to control, and increased catalytic activity of glutathione-S-transferase was found at 0.004 and 0.04 mg/L compared to control (P < 0.05). Juvenile zebrafish turned out to be relatively insensitive to both environmentally relevant (0.004 mg/L) and higher concentrations of salicylic acid.

  12. A Fluorescence-Based Assay for Proteinuria Screening in Larval Zebrafish (Danio rerio)

    PubMed Central

    King, Benjamin L.; Vaske, Bernhard; Haller, Hermann

    2015-01-01

    Abstract Analysis of genes compromising the glomerular filtration barrier in rodent models using transgenic or knockdown approaches is time- and resource-consuming and often leads to unsatisfactory results. Therefore, it would be beneficial to have a selection tool indicating that your gene of interest is in fact associated with proteinuria. Zebrafish (Danio rerio) is a rapid screening tool to study effects in glomerular filtration barrier integrity after genetic manipulation. We use either injection of high-molecular-weight dextrans or a transgenic fluorescent fish line [Tg(l-fabp:DBP:EGFP)] expressing a vitamin D-binding protein fused with eGFP for indirect detection of proteinuria. A loss of high-molecular-weight proteins from the circulation of the fish into the urine can be identified by monitoring fluorescence intensity in the zebrafish eye. Paired with an optimized analysis method, this assay provides an effective screening solution to detect filtration barrier damage with proteinuria before moving to a mammalian system. PMID:26125680

  13. Screening and identification of potential sex-associated sequences in Danio rerio.

    PubMed

    Luzio, Ana; Coimbra, Ana M; Benito, César; Fontaínhas-Fernandes, António A; Matos, Manuela

    2015-10-01

    Current knowledge on zebrafish (Danio rerio) suggests that sex determination has a polygenic genetic basis in this species, although environmental factors may also be involved. This study aimed to identify sex-associated genomic regions using two different marker systems: inter-simple sequence repeats (ISSRs) and random-amplified polymorphic DNA (RAPDs). Two bulks were constructed: one with DNA from zebrafish females and the other from males; then, a total of 100 ISSR and 280 RAPD primers were tested. Three DNA fragments presenting sexual dimorphism (female-linked: OPA17436 and OPQ191027 ; male-linked: OPQ19951 ) were determined from sequential analysis of the bulks followed by assessment in individuals. These fragments were cloned and convert into the following sequenced characterized amplified regions (SCAR): DrSM_F1, DrSM_F2, and DrSM_M, which share identities with sequences located in chromosomes 2, 3, and 11 (Zv9), respectively. Using these potential markers in zebrafish samples it was possible to correctly identify 80% of the males (DrSM_M) and 100% of the females (DrSM_F1 + DrSM_F2) in the analyzed population.

  14. Copper induced upregulation of apoptosis related genes in zebrafish (Danio rerio) gill.

    PubMed

    Luzio, Ana; Monteiro, Sandra M; Fontaínhas-Fernandes, António A; Pinto-Carnide, Olinda; Matos, Manuela; Coimbra, Ana M

    2013-03-15

    Copper (Cu) is an essential micronutrient that, when present in high concentrations, becomes toxic to aquatic organisms. It is known that Cu toxicity may induce apoptotic cell death. However, the precise mechanism and the pathways that are activated, in fish, are still unclear. Thus, this study aimed to assess which apoptotic pathways are triggered by Cu, in zebrafish (Danio rerio) gill, the main target of waterborne pollutants. Fish where exposed to 12.5 and 100 μg/L of Cu during 6, 12, 24 and 48 h. Fish gills were collected to TUNEL assay and mRNA expression analysis of selected genes by real time PCR. An approach to different apoptosis pathways was done selecting p53, caspase-8, caspase-9 and apoptosis inducing factor (AIF) genes. The higher incidence of TUNEL-positive cells, in gill epithelia of the exposed fish, proved that Cu induced apoptosis. The results suggest that different apoptosis pathways are triggered by Cu at different time points of the exposure period, as the increase in transcripts was sequential, instead of simultaneous. Apoptosis seems to be initiated via intrinsic pathway (caspase-9), through p53 activation; then followed by the extrinsic pathway (caspase-8) and finally by the caspase-independent pathway (AIF). A possible model for Cu-induce apoptosis pathways is proposed.

  15. DNA damage and effects on antioxidative enzymes in zebra fish (Danio rerio) induced by atrazine.

    PubMed

    Zhu, Lu-Sheng; Shao, Bo; Song, Yan; Xie, Hui; Wang, Jun; Wang, Jin-Hua; Liu, Wei; Hou, Xin-Xin

    2011-01-01

    The effect of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1, 3, 5-triazine) on the activity of some antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT; and guaiacol peroxidase, POD) and DNA damage induced by atrazine were investigated in zebra fish (Danio rerio). Zebra fish were exposed to four different concentrations of atrazine (0, 2.5, 5, and 10 mg/L) for 7, 14, and 21 days, with three replicates of 10 fishes per treatment. Compared to the controls, the SOD activity in the 2.5 mg/L treatment was markedly stimulated in 21 days, while the SOD activities in the 5 mg/L treatment was stimulated at first and then inhibited. The change of CAT activity at 2.5 mg/L was similar to the SOD activity at 2.5 mg/L. The POD activities in the 2.5, 5, and 10 mg/L treatment were markedly higher on days 14 and 21 compared with the controls. The olive tail moments of single-cell gel electrophoresis (SCGE) of zebra fish enhanced after treatment of different doses on days 7, 14, and 21, and significant differences were found compared to the controls. In conclusion, these findings showed the effect regularity of atrazine to zebra fish, and also provide the basis for the future research of adverse effects induced by atrazine in aquatic ecosystems.

  16. Indole Alkaloids from Fischerella Inhibit Vertebrate Development in the Zebrafish (Danio rerio) Embryo Model

    PubMed Central

    Walton, Katherine; Gantar, Miroslav; Gibbs, Patrick D. L.; Schmale, Michael C.; Berry, John P.

    2014-01-01

    Cyanobacteria are recognized producers of toxic or otherwise bioactive metabolite associated, in particular, with so-called “harmful algal blooms” (HABs) and eutrophication of freshwater systems. In the present study, two apparently teratogenic indole alkaloids from a freshwater strain of the widespread cyanobacterial genus, Fischerella (Stigonemataceae), were isolated by bioassay-guided fractionation, specifically using the zebrafish (Danio rerio) embryo, as a model of vertebrate development. The two alkaloids include the previously known 12-epi-hapalindole H isonitrile (1), and a new nitrile-containing variant, 12-epi-ambiguine B nitrile (2). Although both compounds were toxic to developing embryos, the former compound was shown to be relatively more potent, and to correlate best with the observed embryo toxicity. Related indole alkaloids from Fischerella, and other genera in the Stigonemataceae, have been widely reported as antimicrobial compounds, specifically in association with apparent allelopathy. However, this is the first report of their vertebrate toxicity, and the observed teratogenicity of these alkaloids supports a possible contribution to the toxicity of this widespread cyanobacterial family, particularly in relation to freshwater HABs and eutrophication. PMID:25533520

  17. Identification and Expression Analysis of Zebrafish (Danio rerio) E-Selectin during Embryonic Development.

    PubMed

    Sun, Guijin; Liu, Kechun; Wang, Xue; Liu, Xiuhe; He, Qiuxia; Hsiao, Chung-Der

    2015-01-01

    In this study, we cloned the full-length cDNA of E-selectin of zebrafish (Danio rerio), analyzed its expression pattern and preliminarily explored its biological function. Zebrafish E-selectin cDNA is 3146 bp and encodes a putative 871 amino acid protein. All structural domains involved in E-selectin function are conserved in the putative protein. Whole-mount in situ hybridization of zebrafish at 24 and 48 h post-fertilization (hpf) revealed E-selectin expression mainly in vascular/endothelial progenitor cells in the posterior trunk and blood cells in the intermediate cell mass and posterior cardinal vein regions. Real-time quantitative RT-PCR analysis detected E-selectin expression at 0.2, 24 and 48 hpf and significantly decreased from 48 to 72 hpf. The expression of E-selectin, tumor necrosis factor-α and interleukin-1β was significantly upregulated at 22 to 72 h after induction with bacterial lipopolysaccharide. Thus, the structure of E-selectin protein is highly conserved among species, and E-selectin may be involved in embryonic development and essential for hematopoiesis and angiogenesis during embryonic development in zebrafish. Furthermore, we provide the first evidence of inflammatory mediators inducing E-selectin expression in non-mammalian vertebrates, which suggests that zebrafish E-selectin may be involved in inflammation and probably has similar biological function to mammalian E-selectin. PMID:26473817

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

    PubMed

    Bilberg, Katrine; Hovgaard, Mads Bruun; Besenbacher, Flemming; Baatrup, Erik

    2012-01-01

    The influence of water chemistry on characterised polyvinyl pyrrolidone- (PVP-) coated silver nanoparticles (81 nm) was investigated. NaCl solution series of 100-800 mg L(-1) lead to initial and temporal increase in nanoparticles size, but agglomeration was limited. pH variation (5-8) had only minor influence on the hydrodynamic particle size. Acute toxicity of nanosivler to zebrafish (Danio rerio) was investigated in a 48-hour static renewal study and compared with the toxicity of silver ions (AgNO(3)). The nanosilver and silver ion 48-hour median lethal concentration (LC(50)) values were 84 μg L(-1) and 25 μg L(-1), respectively. To investigate exposure-related stress, the fish behaviour was observed visually after 0, 3, 6, 12, 24, 27, 30, and 48 hours of both nanosilver and ionic silver treatments. These observations revealed increased rate of operculum movement and surface respiration after nanosilver exposure, suggesting respiratory toxicity. The present study demonstrates that silver nanoparticles are lethal to zebrafish.

  19. Uptake and depuration of polycyclic aromatic hydrocarbons from sediment by the zebrafish (Brachydanio rerio)

    SciTech Connect

    Djomo, J.E.; Garrigues, P.; Narbonne, J.F.

    1996-07-01

    Zebrafish (Brachydanio rerio) were exposed for 30 d to individual {sup 14}C-labeled polycyclic aromatic hydrocarbons (PAHs) (anthracene, phenanthrene, pyrene, or benzo[a]pyrene) adsorbed on sediment. The uptake and depuration rate constants were measured. Rate of radioactivity release was measured under both contaminated (experiment 1) and clean (experiment 2) conditions. The results confirm that uptake and depuration rate constants were strongly related to physicochemical properties. However, the uptake from the water compartment was rapidly decreased in the microcosm system ({minus}83% for anthracene and phenanthrene, {minus}71% for pyrene, and {minus}59% for benzo[a]pyrene within the first 2 d). For depuration in clean water, the half-lives of radioactivity loss from whole body were 63, 97, 115, and 138 h for anthracene, phenanthrene, pyrene, and benzo[a]pyrene, respectively, and were positively correlated with log K{sub ow}. In experiment 1 after 10 d, the remaining PAH concentrations were only about 16% of the maximum concentrations measured at time 24 h for anthracene, 12% for phenanthrene, 30% for pyrene, and 46% for benzo[a]pyrene. K{sub ow} appears to be a determining factor for partitioning constants for sorption to sediment, uptake, and release in aquatic organisms.

  20. Molecular cloning and expression analysis of an apoptosis-associated gene Daxx from zebrafish, Danio rerio.

    PubMed

    Qi, Lin; Xiang, Zhiming

    2015-07-01

    The death domain-associated protein Daxx exerts many functions including the induction and inhibition of apoptosis, regulation of chromatin remodeling and gene transcription. In this report, we have cloned and characterized a Daxx ortholog from the zebrafish, Danio rerio. The bioinformatics analysis results indicated that the open reading frame (ORF) of zebrafish Daxx is 2,151bp long and encodes a putative protein of 716 amino acids containing Daxx domain. Though quantitative PCR analyses, Daxx mRNA was detected in embryonic development from 6 h to 120 h and in all 11 selected zebrafish tissues, and the expression of Daxx was increased first and then decreased during megalocytivirus infectious spleen and kidney necrosis virus (ISKNV) infection. Fluorescence microscopy indicated that the full-length protein was located in the nuclei of the tested Hela cells uniformly but punctiform distribution in HEK293T. In the luciferase report assays, the GAL4-Daxx fusion protein inhibited the transcriptional activity of L8G5-Luc reporter gene showed that Daxx might act as a transcriptional repressor, following the over-expression in HEK293T, the activation of NF-κB-Luc and p53/p21-Luc reporter genes were repressed by the protein. These results suggested that Daxx might play definite role in apoptosis and innate immunity in zebrafish.

  1. Comparative analysis of the acute response of zebrafish Danio rerio skin to two different bacterial infections.

    PubMed

    Lü, Aijun; Hu, Xiucai; Wang, Yi; Shen, Xiaojing; Zhu, Aihua; Shen, Lulu; Ming, Qinglei; Feng, Zhaojun

    2013-12-01

    Skin is an important innate immune organ in fish; however, little is known about the skin's immune response to infectious pathogens. We conducted a comparative analysis of the acute immune response of Zebrafish Danio rerio skin against gram-positive (Staphylococcus chromogenes) and gram-negative (Citrobacter freundii) bacterial infections. Gene expression profiles induced from the two different infections were identified by microarray hybridization, with many genes demonstrating an acute immune response in the skin. Differentially expressed genes were mainly involved in response to stress and stimulus, complement activation, acute-phase response, and defense and immune response. Compared with transcription patterns of skin from the two infections, a similar innate immunity (e.g., transferrin, coagulation factor, complements, and lectins) was observed but with different acute-phase genes (e.g., ceruloplasmin, alpha-1-microglobulin, vitellogenin, and heat shock protein). These results suggest that the skin of fish plays an important role in the innate immune responses to bacterial infection. PMID:24341765

  2. Comparative effects of biological and chemical dispersants on the bioavailability and toxicity of crude oil to early life stages of marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jingli; Jin, Fei; Ma, Xindong; Lin, Zhongsheng; Wang, Juying

    2014-11-01

    The authors assessed the bioavailability and chronic toxicity of water-accommodated fractions of crude oil (WAFs) and 2 dispersants plus dispersed crude oil (chemical dispersant + crude oil [CE-WAF] and biological dispersant + crude oil [BE-WAF]) on the early life stages of marine medaka, Oryzias melastigma. The results showed that the addition of the 2 dispersants caused a 3- and 4-fold increase in concentrations of summed priority polycyclic aromatic hydrocarbons (PAHs) and high-molecular-weight PAHs with 3 or more benzene rings. The chemical and biological dispersants increased the bioavailability (as measured by ethoxyresorufin-O-dethylase activity) of crude oil 6-fold and 3-fold, respectively. Based on nominal concentrations, chronic toxicity (as measured by deformity) in WAFs exhibited a 10-fold increase in CE-WAF and a 3-fold increase in BE-WAF, respectively. When total petroleum hydrocarbon was measured, the differences between WAF and CE-WAF treatments disappeared, and CE-WAF was approximately 10 times more toxic than BE-WAF. Compared with the chemical dispersant, the biological dispersant possibly modified the toxicity of oil hydrocarbons because of the increase in the proportion of 2- and 3-ringed PAHs in water. The chemical and biological dispersants enhanced short-term bioaccumulation and toxicity, through different mechanisms. These properties should be considered in addition to their efficacy in degrading oil when oil spill management strategies are selected. PMID:25113786

  3. Comparative effects of biological and chemical dispersants on the bioavailability and toxicity of crude oil to early life stages of marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jingli; Jin, Fei; Ma, Xindong; Lin, Zhongsheng; Wang, Juying

    2014-11-01

    The authors assessed the bioavailability and chronic toxicity of water-accommodated fractions of crude oil (WAFs) and 2 dispersants plus dispersed crude oil (chemical dispersant + crude oil [CE-WAF] and biological dispersant + crude oil [BE-WAF]) on the early life stages of marine medaka, Oryzias melastigma. The results showed that the addition of the 2 dispersants caused a 3- and 4-fold increase in concentrations of summed priority polycyclic aromatic hydrocarbons (PAHs) and high-molecular-weight PAHs with 3 or more benzene rings. The chemical and biological dispersants increased the bioavailability (as measured by ethoxyresorufin-O-dethylase activity) of crude oil 6-fold and 3-fold, respectively. Based on nominal concentrations, chronic toxicity (as measured by deformity) in WAFs exhibited a 10-fold increase in CE-WAF and a 3-fold increase in BE-WAF, respectively. When total petroleum hydrocarbon was measured, the differences between WAF and CE-WAF treatments disappeared, and CE-WAF was approximately 10 times more toxic than BE-WAF. Compared with the chemical dispersant, the biological dispersant possibly modified the toxicity of oil hydrocarbons because of the increase in the proportion of 2- and 3-ringed PAHs in water. The chemical and biological dispersants enhanced short-term bioaccumulation and toxicity, through different mechanisms. These properties should be considered in addition to their efficacy in degrading oil when oil spill management strategies are selected.

  4. Assessment of multiple hormone activities of a UV-filter (octocrylene) in zebrafish (Danio rerio).

    PubMed

    Zhang, Qiuya Y; Ma, Xiaoyan Y; Wang, Xiaochang C; Ngo, Huu Hao

    2016-09-01

    In this study, zebrafish (Danio rerio) were exposed to a UV-filter-octocrylene (OCT) with elevated concentrations for 28 d. The total body accumulation of OCT in zebrafish was found to reach 2321.01 ("L" level), 31,234.80 ("M" level), and 70,593.38 ng g(-1) ("H" level) when the average OCT exposure concentration was controlled at 28.61, 505.62, and 1248.70 μg L(-1), respectively. Gross and histological observations as well as RT-qPCR analysis were conducted to determine the effects of OCT accumulation on zebrafish. After exposure, the gonad-somatic index and percentage of vitellogenic oocytes were found to increase significantly in the ovaries of female zebrafish at the H accumulation level. Significant up-regulation of esr1 and cyp19b were observed in the gonads, as well as vtg1 in the livers for both female and male zebrafish. At M and H accumulation levels, apparent down-regulation of ar was observed in the ovaries and testis of the female and male zebrafish, respectively. Although the extent of the effects on zebrafish differed at different accumulation levels, the induction of vtg1 and histological changes in the ovaries are indications of estrogenic activity and the inhibition of esr1 and ar showed antiestrogenic and antiandrogenic activity, respectively. Thus, as OCT could easily accumulate in aquatic life such as zebrafish, one of its most of concern hazards would be the disturbance of the histological development and its multiple hormonal activities. PMID:27337435

  5. Molecular cloning and biochemical characterization of sialidases from zebrafish (Danio rerio)

    PubMed Central

    Manzoni, Marta; Colombi, Paolo; Papini, Nadia; Rubaga, Luana; Tiso, Natascia; Preti, Augusto; Venerando, Bruno; Tettamanti, Guido; Bresciani, Roberto; Argenton, Francesco; Borsani, Giuseppe; Monti, Eugenio

    2007-01-01

    Sialidases remove sialic acid residues from various sialo-derivatives. To gain further insights into the biological roles of sialidases in vertebrates, we exploited zebrafish (Danio rerio) as an animal model. A zebrafish transcriptome- and genome-wide search using the sequences of the human NEU polypeptides as templates revealed the presence of seven different genes related to human sialidases. neu1 and neu4 are the putative orthologues of the mammalian sialidases NEU1 and NEU4 respectively. Interestingly, the remaining genes are organized in clusters located on chromosome 21 and are all more closely related to mammalian sialidase NEU3. They were thus named neu3.1, neu3.2, neu3.3, neu3.4 and neu3.5. Using RT–PCR (reverse transcription–PCR) we detected transcripts for all genes, apart from neu3.4, and whole-mount in situ hybridization experiments show a localized expression pattern in gut and lens for neu3.1 and neu4 respectively. Transfection experiments in COS7 (monkey kidney) cells demonstrate that Neu3.1, Neu3.2, Neu3.3 and Neu4 zebrafish proteins are sialidase enzymes. Neu3.1, Neu3.3 and Neu4 are membrane-associated and show a very acidic pH optimum below 3.0, whereas Neu3.2 is a soluble sialidase with a pH optimum of 5.6. These results were further confirmed by subcellular localization studies carried out using immunofluorescence. Moreover, expression in COS7 cells of these novel zebrafish sialidases (with the exception of Neu3.2) induces a significant modification of the ganglioside pattern, consistent with the results obtained with membrane-associated mammalian sialidases. Overall, the redundancy of sialidases together with their expression profile and their activity exerted on gangliosides of living cells indicate the biological relevance of this class of enzymes in zebrafish. PMID:17708749

  6. The effects of henna (hair dye) on the embryonic development of zebrafish (Danio rerio).

    PubMed

    Manjunatha, Bangeppagari; Wei-bing, Peng; Ke-chun, Liu; Marigoudar, Shambanagouda R; Xi-qiang, Chen; Xi-min, Wang; Xue, Wang

    2014-09-01

    The powder of henna is extensively used as decorative skin paint for nail coloring and as a popular hair dye in Asian countries. Its human health risk is extensive, and it is frequently released as waste into the aquatic environment raising the concerns. Zebrafish (Danio rerio) embryos were employed to study the developmental effects of henna. Normal fertilized zebrafish embryos under standard water were selected for the control and test chambers. Three predetermined sublethal concentrations (100, 200, and 275 μM) of henna in 24-well cell culture plates were tested on 1-h postfertilized embryo (pfe) for 96 h. Observation for rates of survival and mortality was recorded; digital camera was used to image morphological anomalies of embryos with a stereomicroscope; and functional abnormalities at 24, 48, 72, and 96 h were performed. The hatching rates of embryos were reduced significantly when treated with 200 and 275 μM or higher concentrations of henna. Slow blood circulation in the whole body was observed with a median effect on hatching exposed to 200 and 275 μM of henna at 48-h pfe. At 72- and 96-h pfe, blood circulation was ceased in the whole body but still had a heartbeat. At 96-h pfe, pericardial sac edema, yolk sac edema, head deformation, spine crooked malformation, and tail malformation (bent tails or hook-like tails) were observed in the surviving larvae at 100 μM. In summary, exposure to henna at 100, 200, and 275 μM causes some altered morphological and physiological abnormalities including increased mortality, hatching delay, slow blood circulation, pericardial sac edema, yolk sac edema, abnormal body axes, twisted notochord, tail deformation, weak heartbeat, and growth retardation and was also detected in some treated embryos and groups having adverse effects on embryonic development of zebrafish provoking potential human developmental risk studies. PMID:24859694

  7. Effect-directed analysis of Elizabeth River porewater: developmental toxicity in zebrafish (Danio rerio).

    PubMed

    Fang, Mingliang; Getzinger, Gordon J; Cooper, Ellen M; Clark, Bryan W; Garner, Lindsey V T; Di Giulio, Richard T; Ferguson, P Lee; Stapleton, Heather M

    2014-12-01

    In the present study, effect-directed analysis was used to identify teratogenic compounds in porewater collected from a Superfund site along the Elizabeth River estuary (VA, USA). Zebrafish (Danio rerio) exposed to the porewater displayed acute developmental toxicity and cardiac teratogenesis, presumably because of elevated sediment levels of polycyclic aromatic hydrocarbons (PAHs) from historical creosote use. Pretreatment of porewater with several physical and chemical particle removal methods revealed that colloid-bound chemicals constituted the bulk of the observed toxicity. Size-exclusive chromatography and normal-phase high-performance liquid chromatography were used to fractionate Elizabeth River porewater. Acute toxicity of porewater extracts and extract fractions was assessed as the pericardial area in embryonic zebrafish. The most toxic fraction contained several known aryl hydrocarbon receptor (AhR) agonists (e.g., 1,2-benzofluorene and 1,2-benzanthracene) and cytochrome P450 A1 (CPY1A) inhibitors (e.g., dibenzothiophene and fluoranthene). The second most toxic fraction contained known AhR agonists (e.g., benzo[a]pyrene and indeno[1,2,3-cd]pyrene). Addition of a CYP1A inhibitor, fluoranthene, increased toxicity in all active porewater fractions, suggesting synergism between several contaminants present in porewaters. The results indicate that the observed acute toxicity associated with Elizabeth River porewater results from high concentrations of AhR agonistic PAHs and mixture effects related to interactions between compounds co-occurring at the Elizabeth River site. However, even after extensive fractionation and chemical characterization, it remains plausible that some active compounds in Elizabeth River porewater remain unidentified.

  8. Copper acutely impairs behavioral function and muscle acetylcholinesterase activity in zebrafish (Danio rerio).

    PubMed

    Haverroth, Gabriela M B; Welang, Chariane; Mocelin, Riciéri N; Postay, Daniela; Bertoncello, Kanandra T; Franscescon, Francini; Rosemberg, Denis B; Dal Magro, Jacir; Dalla Corte, Cristiane L

    2015-12-01

    Copper is a heavy metal found at relatively high concentrations in surface waters around the world. Copper is a micronutrient at low concentrations and is essential to several organisms. At higher concentrations copper can become toxic, which reveal the importance of studying the toxic effects of this metal on the aquatic life. Thus, the objective of this study was to evaluate the toxic effects of copper on the behavior and biochemical parameters of zebrafish (Danio rerio). Zebrafish were exposed for 24h at a concentration of 0.006 mg/L Cu. After the exposure period, behavioral profile of animals was recorded through 6 min using two different apparatuses tests: the Novel Tank and the Light-Dark test. After behavioral testing, animals were euthanized with a solution of 250 mg/L of tricaine (MS-222). Brain, muscle, liver and gills were extracted for analysis of parameters related to oxidative stress and accumulation of copper in these tissues. Acetylcholinesterase (AChE) activity was determined in brain and muscle. Results showed acute exposure to copper induces significant changes in behavioral profile of zebrafish by changing locomotion and natural tendency to avoid brightly lit area. On the other hand, there were no significant effects on parameters related to oxidative stress. AChE activity decreased significantly in zebrafish muscle, but there were no significant changes in cerebral AChE activity. Copper levels in tissues did not increase significantly compared to the controls. Taken together, these results indicate that a low concentration of copper can acutely affect behavioral profile of adult zebrafish which could be partially related to an inhibition on muscle AChE activity. These results reinforce the need of additional tests to establishment of safe copper concentrations to aquatic organisms and the importance of behavioral parameters in ecotoxicological studies.

  9. Effects of the number of subjects on the dark/light preference of Zebrafish (Danio rerio).

    PubMed

    Mansur, Bruno de Matos; Dos Santos, Bruno Rodrigues; Dias, Cláudio Alberto Gellis de Mattos; Pinheiro, Marcelo de Sena; Gouveia, Amauri

    2014-12-01

    This research aims to describe the effects of a variable number of Danio rerio fish subjects, ranging from one to eight, in the light/dark box preference test. Four hundred eighty adult male short-finned phenotype zebrafish were tested in the light/dark box. There were four groups in this experiment and a different number of subjects was used in each group: the control group had only one subject, whereas the experimental groups had either two, four, or eight subjects simultaneously inside the apparatus in every session. The average occurrence (AO) of subjects in the white side of the aquarium and the first choice average (FC) were recorded. The AO revealed no difference between the control group and test groups with two and four subjects. The results for the test group with eight subjects showed significant difference when compared to the control group and from the test group with two subjects. The FC also showed no difference between the control group and test groups with two and four subjects. There was significant variation between the control and the test group with eight subjects. The results reflect a conflict between the animal's preference for dark places and the innate drive to explore new environments. Zebrafish are highly social animals, exhibiting preference for swimming in groups and other patterns of social cohesion. The reduced white avoidance behavior in the test group of eight subjects may possibly reflect the role of shoaling, which is a defensive behavior, in reducing anxiety and stress. On the other hand, the absence of difference between the control group and test groups with two and four subjects suggest that it is feasible to run the light/dark test with up to four subjects, becoming an alternative to streamline and simplify data collection and test analysis.

  10. Embryonic Stage-Dependent Teratogenicity of Ketamine in Zebrafish (Danio rerio).

    PubMed

    Félix, Luís M; Serafim, Cindy; Valentim, Ana M; Antunes, Luís M; Campos, Sónia; Matos, Manuela; Coimbra, Ana M

    2016-08-15

    Ketamine, a widely used anesthetic, has been shown to have NMDA receptor dependent and independent actions during zebrafish (Danio rerio) embryogenesis. Notwithstanding, the effects of developmental toxicity and the mechanisms of ketamine action on fish embryos are still not well understood, and its implications for early vertebrate development remains to be clarified. In this work, zebrafish embryos were exposed to ketamine (0.2, 0.4, and 0.8 mg mL(-1)) in order to study the stage-developmental toxicity of this pharmaceutical. During 256-cell (2.5 h post-fertilization, hpf), 50% epiboly (5.5 hpf) and 1-4 somites (10.5 hpf), embryos were exposed to the referred ketamine concentrations for a period of 20 min and were allowed to grow until 144 hpf. Both lethal and nonlethal parameters were evaluated. Skeletal development was assessed by alcian blue and calcein staining. Additionally, the expression of the developmental genes sonic hedgehog a (shh a) and noggin 3 (nog3) was evaluated. Similar to our previous work, bone and cartilage malformations were observed after 256-cell exposure. During 50% epiboly, ketamine exposure induced concentration-dependent mortality and malformations, such as lordosis and/or kyphosis and microcephaly, namely, at higher concentrations. Conversely, exposure during 1-4 somites showed the induction of nonspecific effects with no rise in mortality. The quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed differences in shh a and nog3 expressions comparatively to the control group. Overall, this study shows that the ketamine toxic profile is developmental phase-dependent with 256-cell being the most susceptible phase. The effects observed may result from ketamine interaction with cellular signaling pathways that merits further investigation. PMID:27359275

  11. Effects of β-diketone antibiotic mixtures on behavior of zebrafish (Danio rerio).

    PubMed

    Wang, Xuedong; Zheng, Yuansi; Zhang, Yuna; Li, Jieyi; Zhang, Hongqin; Wang, Huili

    2016-02-01

    To date, few data are available on neurotoxicity of β-diketone antibiotics (DKAs) from the perspective of animal behavior. Herein, the effects of long-term DKAs exposure on zebrafish (Danio rerio) behavior were assessed for locomotor activity, anxiety, social interaction and their related molecular mechanisms. DKAs exposure to zebrafish consisted of six DKA species, including ofloxacin, ciprofloxacin, enrofloxacin, doxycycline, chlortetracycline and oxytetracycline, with equal weight concentration and equal volume. DKAs at 6.25 mg/L significantly increased the time spent in the upper portion of the test tank (+40%) and the number of line crossings (±42%), indicating occurrence of anxiolytic behavior. For conditioned place preference test, long-term DKAs exposure at 6.25 mg/L increased the number of motionless positions in the non-preferred white side (+31%), number of transitions to the white side (+221%) and time spent in the white side (+35%) in relation to the control. DKAs at 6.25 mg/L significantly increased zebrafish shoaling behavior (+38%) resulting from an anxiety-like state, but 25 mg/L DKAs exposure decreased zebrafish social cohesion (-41%) possibly due to an autism-like state. With increasing DKAs-exposure concentration, the signal intensity of (1)O2 gradually decreased, leading to insufficient energy supply and movement functional disorders. Based on GO functional annotation and metabolic pathway analysis, 11 genes closely associated with locomotor behavior were identified. Using qRT-PCR, we confirmed that DKAs exposure led to changes in the transcriptional levels of 11 locomotor-related genes. These results suggest that behavior is a potential strategy for evaluating mechanisms underlying the neurochemical basis triggered by stress in zebrafish. PMID:26595314

  12. Copper acutely impairs behavioral function and muscle acetylcholinesterase activity in zebrafish (Danio rerio).

    PubMed

    Haverroth, Gabriela M B; Welang, Chariane; Mocelin, Riciéri N; Postay, Daniela; Bertoncello, Kanandra T; Franscescon, Francini; Rosemberg, Denis B; Dal Magro, Jacir; Dalla Corte, Cristiane L

    2015-12-01

    Copper is a heavy metal found at relatively high concentrations in surface waters around the world. Copper is a micronutrient at low concentrations and is essential to several organisms. At higher concentrations copper can become toxic, which reveal the importance of studying the toxic effects of this metal on the aquatic life. Thus, the objective of this study was to evaluate the toxic effects of copper on the behavior and biochemical parameters of zebrafish (Danio rerio). Zebrafish were exposed for 24h at a concentration of 0.006 mg/L Cu. After the exposure period, behavioral profile of animals was recorded through 6 min using two different apparatuses tests: the Novel Tank and the Light-Dark test. After behavioral testing, animals were euthanized with a solution of 250 mg/L of tricaine (MS-222). Brain, muscle, liver and gills were extracted for analysis of parameters related to oxidative stress and accumulation of copper in these tissues. Acetylcholinesterase (AChE) activity was determined in brain and muscle. Results showed acute exposure to copper induces significant changes in behavioral profile of zebrafish by changing locomotion and natural tendency to avoid brightly lit area. On the other hand, there were no significant effects on parameters related to oxidative stress. AChE activity decreased significantly in zebrafish muscle, but there were no significant changes in cerebral AChE activity. Copper levels in tissues did not increase significantly compared to the controls. Taken together, these results indicate that a low concentration of copper can acutely affect behavioral profile of adult zebrafish which could be partially related to an inhibition on muscle AChE activity. These results reinforce the need of additional tests to establishment of safe copper concentrations to aquatic organisms and the importance of behavioral parameters in ecotoxicological studies. PMID:26386335

  13. Ultraviolet-B radiation effects on antioxidant status and survival in the zebrafish, Brachydanio rerio.

    PubMed

    Charron, R A; Fenwick, J C; Lean, D R; Moon, T W

    2000-09-01

    Direct impact of ambient (1.95 W/m2) and subambient doses of UV-B radiation on muscle/skin tissue antioxidant status was assessed in mature zebrafish (Brachydanio rerio). The influence of these doses on hatching success and survival in earlier life stages was also examined. Subambient doses of UV-B radiation in the presence (1.28 W/m2) and absence (1.72 W/m2) of a cellulose acetate filter significantly depressed muscle/skin total glutathione (TGSH) levels compared with controls (0.15 W/m2) and low (0.19 W/m2) UV-B-treated fish after 6 and 12 h cumulative exposure. Ambient UV-B exposure significantly decreased muscle/skin glutathione peroxidase (GPx) activity after a 6 h exposure; activities of glutathione reductase (GR) were unchanged over this exposure period. Superoxide dismutase (SOD) and catalase activities peaked after 6 and 12 h cumulative exposure, respectively, but fell back to control levels by the end of the exposure period. The changes in tissue antioxidant status suggested UV-B-mediated increases in cytosolic superoxide anion radicals (O2-) and hydrogen peroxide (H2O2). This apparent UV-B-mediated increase in oxidative stress is further supported by a significant increase in muscle/skin thiobarbituric acid reactive substances (TBARS). Hatching success of newly fertilized eggs continuously exposed to ambient UV-B was only 2% of the control value. Even at 30 and 50% of ambient UV-B, hatching success was only 80 and 20%, respectively, of the control. Newly hatched larvae exposed to an ambient dose of UV-B, experienced 100% mortality after a 12 h cumulative exposure period. This study supports a major impact of UV-B on both the mature and embryonic zebrafish. PMID:10989602

  14. Sexual dimorphisms in swimming behavior, cerebral metabolic activity and adrenoceptors in adult zebrafish (Danio rerio).

    PubMed

    Ampatzis, Konstantinos; Dermon, Catherine R

    2016-10-01

    Sexually dimorphic behaviors and brain sex differences, not only restricted to reproduction, are considered to be evolutionary preserved. Specifically, anxiety related behavioral repertoire is suggested to exhibit sex-specific characteristics in rodents and primates. The present study investigated whether behavioral responses to novelty, have sex-specific characteristics in the neurogenetic model organism zebrafish (Danio rerio), lacking chromosomal sex determination. For this, aspects of anxiety-like behavior (including reduced exploration, increased freezing behavior and erratic movement) of male and female adult zebrafish were tested in a novel tank paradigm and after habituation. Male and female zebrafish showed significant differences in their swimming activity in response to novelty, with females showing less anxiety spending more time in the upper tank level. When fish have habituated, regional cerebral glucose uptake, an index of neuronal activity, and brain adrenoceptors' (ARs) expression (α2-ARs and β-ARs) were determined using in vivo 2-[(14)C]-deoxyglucose methodology and in vitro neurotransmitter receptors quantitative autoradiography, respectively. Intriguingly, females exhibited higher glucose utilization than males in hypothalamic brain areas. Adrenoceptor's expression pattern was dimorphic in zebrafish telencephalic, preoptic, hypothalamic nuclei, central gray, and cerebellum, similarly to birds and mammals. Specifically, the lateral zone of dorsal telencephalon (Dl), an area related to spatial cognition, homologous to the mammalian hippocampus, showed higher α2-AR densities in females. In contrast, male cerebellum included higher densities of β-ARs in comparison to female. Taken together, our data demonstrate a well-defined sex discriminant cerebral metabolic activity and ARs' pattern in zebrafish, possibly contributing to male-female differences in the swimming behavior.

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

    PubMed

    Kinnberg, Karin L; Petersen, Gitte I; Albrektsen, Mette; Minghlani, Mita; Awad, Suad Mohamud; Holbech, Bente F; Green, John W; Bjerregaard, Poul; Holbech, Henrik

    2015-12-01

    The chemical ultraviolet (UV) filter benzophenone-3 (BP-3) is suspected to be an endocrine disruptor based on results from in vitro and in vivo testing. However, studies including endpoints of endocrine adversity are lacking. The present study investigated the potential endocrine-disrupting effects of BP-3 in zebrafish (Danio rerio) in the Fish Sexual Development Test (Organisation for Economic Co-operation and Development TG 234) and a 12-d adult male zebrafish study. In TG 234, exposure from 0 d to 60 d posthatch caused a monotone dose-dependent skewing of the phenotypic sex ratio toward fewer males and more female zebrafish (no observed effect concentration [NOEC]: 191 μg/L, lowest observed effect concentration [LOEC]: 388 μg/L). Besides, gonad maturation was affected in both female fish (NOEC 191 μg/L, LOEC 388 μg/L) and male fish (NOEC 388 μg/L, LOEC 470 μg/L). Exposure to BP-3 did not affect the vitellogenin concentration in TG 234. After 12 d exposure of adult male zebrafish, a slight yet significant increase in the vitellogenin concentration was observed at 268 μg/L but not at 63 μg/L and 437 μg/L BP-3. Skewing of the sex ratio is a marker of an endocrine-mediated mechanism as well as a marker of adversity, and therefore the conclusion of the present study is that BP-3 is an endocrine-disrupting chemical in accordance with the World Health Organization's definition.

  16. PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.

    PubMed

    Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

    2014-10-01

    As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. PMID:25048891

  17. Thyroid hormone actions are temperature-specific and regulate thermal acclimation in zebrafish (Danio rerio)

    PubMed Central

    2013-01-01

    Background Thyroid hormone (TH) is best known for its role in development in animals, and for its control of metabolic heat production (thermogenesis) during cold acclimation in mammals. It is unknown whether the regulatory role of TH in thermogenesis is derived in mammals, or whether TH also mediates thermal responses in earlier vertebrates. Ectothermic vertebrates show complex responses to temperature variation, but the mechanisms mediating these are poorly understood. The molecular mechanisms underpinning TH action are very similar across vertebrates, suggesting that TH may also regulate thermal responses in ectotherms. We therefore aimed to determine whether TH regulates thermal acclimation in the zebrafish (Danio rerio). We induced hypothyroidism, followed by supplementation with 3,5-diiodothyronine (T2) or 3,5,3′-triiodothyronine (T3) in zebrafish exposed to different chronic temperatures. We measured whole-animal responses (swimming performance and metabolic rates), tissue-specific regulatory enzyme activities, gene expression, and free levels of T2 and T3. Results We found that both T3 and the lesser-known T2, regulate thermal acclimation in an ectotherm. To our knowledge, this is the first such study to show this. Hypothyroid treatment impaired performance measures in cold-acclimated but not warm-acclimated individuals, whereas supplementation with both TH metabolites restored performance. TH could either induce or repress responses, depending on the actual temperature and thermal history of the animal. Conclusions The low sensitivity to TH at warm temperatures could mean that increasing temperatures (that is, global warming) will reduce the capacity of animals to regulate their physiologies to match demands. We suggest that the properties that underlie the role of TH in thermal acclimation (temperature sensitivity and metabolic control) may have predisposed this hormone for a regulatory role in the evolution of endothermy. PMID:23531055

  18. Edwardsiellosis Caused by Edwardsiella ictaluri in Laboratory Populations of Zebrafish Danio rerio

    PubMed Central

    Hawke, John P.; Kent, Michael; Rogge, Matt; Baumgartner, Wes; Wiles, Judy; Shelley, Johnny; Savolainen, L. Christine; Wagner, Robert; Murray, Katy; Peterson, Tracy S.

    2014-01-01

    We report the first cases of Edwardsiella ictaluri causing epizootics in laboratory populations of Zebrafish Danio rerio. Edwardsiella ictaluri is primarily recognized as a disease of catfish species and is known to cause an economically important bacterial disease of farm-raised catfish in the USA and abroad; however, it has been isolated on occasion from 10 other genera of nonictalurid fishes. We isolated E. ictaluri from moribund Zebrafish held in quarantine at two different universities in two states and from a research facility in a third state between February 23 and December 6, 2011. Edwardsiellosis in Zebrafish can be described as a severe systemic disease characterized by tissue necrosis and the presence of large numbers of extracellular and intracellular bacteria, often within macrophages. The kidneys (pronephros and mesonephros), spleen, nares, and forebrain were the most commonly and severely affected tissues. In outbreaks, mortality was acute and numerous fish died over a 1–2 week period. Mortality continued until the majority of the population was lost, at which time the remaining fish were euthanized. In addition to these cases, four cultures of bacteria isolated from Zebrafish by another diagnostic laboratory were submitted to the Louisiana Aquatic Diagnostic Laboratory for identification and were confirmed as E. ictaluri. In total, eight cultures of E. ictaluri from Zebrafish from Louisiana, Massachusetts, Pennsylvania, and Florida were identified. The isolates were confirmed as E. ictaluri by biochemical phenotype, API 20E (bioMérieux), and amplification and sequencing of a portion of the 16S rRNA gene. Edwardsiella ictaluri isolates from Zebrafish are believed to comprise a unique group and were differentiated from catfish isolates by exhibiting weaker motility, autoaggregation in broth, a different plasmid profile (two plasmids of 4.0 and 3.5 kb), a different API 20E code (4204000), and lack of lipopolysaccharide recognition with Mab Ed9

  19. Pseudoloma neurophilia infections in zebrafish Danio rerio: effects of stress on survival, growth, and reproduction.

    USGS Publications Warehouse

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

    2009-01-01

    Pseudoloma neurophilia (Microsporidia) is a common disease of zebrafish Danio rerio, including those used as research models. We conducted a study comprised of 4 separate experiments to determine the effects of husbandry stress on preexisting and experimental P. neurophilia infections and the subsequent effects on survival, infection onset and intensity, fish growth, and reproduction. In fish (AB strain) with preexisting infections, stress or feeding cortisol significantly increased mortality over 7 wk compared to no stress or cortisol treatment. In contrast, no mortality was observed in fish (TL strain) experimentally exposed to P. neurophilia over 10 wk. A third experiment involved experimental exposure of AB fish to P. neurophilia and exposure to crowding and handling stressors. No mortality was associated with P. neurophilia regardless of stress treatment over a period of 20 wk. However, the onset of infection occurred sooner in stress-treated fish. Stress significantly increased the mean intensity of infection (described as xenoma area/spinal cord area in histological sections) at Week 20 post-exposure (PE). In fish with preexisting infections, myositis was significantly greater in stressed and cortisol-treated fish than those not stressed. With experimental exposure of AB fish, stressed and infected groups weighed significantly less than the control group at Week 20 PE. Regarding fecundity, the number of larvae hatched at 5 d post fertilization was negatively associated with mean infection intensity among P. neurophilia-infected and stressed AB fish. These experiments are the first to show empirically that P. neurophilia can be associated with reduced weight and fecundity, and that stress can exacerbate the severity of the infection.

  20. Life-cycle exposure to the estrogenic mycotoxin zearalenone affects zebrafish (Danio rerio) development and reproduction.

    PubMed

    Schwartz, Patrick; Bucheli, Thomas D; Wettstein, Felix E; Burkhardt-Holm, Patricia

    2013-05-01

    Zearalenone (ZON) is one of the worldwide most common mycotoxin and exhibits estrogenic activity in the range of natural steroid estrogens. The occurrence of ZON has been reported in soil, drainage water, wastewater effluents, and rivers, but its ecotoxicological effects on fish have hardly been investigated. The consequences of continuous long-term ZON exposure, including a subsequent depuration period, as well as transgenerational effects of F0 short-term exposure on F1 generation were investigated. Effects on growth, reproduction activity, physiology, and morphology of zebrafish (Danio rerio) were examined in a 182 day live-cycle experiment. Life-long exposure to ZON for 140 days increased wet weight, body length, and condition factor of female fish at 1000 ng/L, and sex ratio was shifted toward female from 320 ng/L ZON. Only females at 1000 ng/L ZON revealed a 1.5-fold induction of plasma vitellogenin (VTG). Relative fecundity at 1000 ng/L recovered significantly during the depuration period. An increased condition factor in adult female F1 fish implies that exposure of F0 generation to 1000 ng/L ZON affected growth of F1 generation. A negative correlation between relative fecundity in the F1 generation (all groups exposed to 320 ng/L ZON) and the nominal ZON concentrations of the F0 exposure might indicate an influence of F0 exposure on reproductive performance of F1 generation. No exposure scenario affected fertility, hatch, embryo survival, and gonad morphology of zebrafish. Evaluating the environmental relevance of this data, the risk for fish to be harmed by exposure to ZON solely seems rather marginal, but ZON might contribute to the overall estrogenicity in the environment. © 2011 Wiley Periodicals, Inc. Environ Toxicol 2013.

  1. Zinc oxide nanoparticles alter hatching and larval locomotor activity in zebrafish (Danio rerio).

    PubMed

    Chen, Te-Hao; Lin, Chia-Chi; Meng, Pei-Jie

    2014-07-30

    Zinc oxide nanoparticles (ZnO NP) are extensively used in various consumer products such as sunscreens and cosmetics, with high potential of being released into aquatic environments. In this study, fertilized zebrafish (Danio rerio) eggs were exposed to various concentrations of ZnO NP suspensions (control, 0.1, 0.5, 1, 5, and 10mg/L) or their respective centrifuged supernatants (0.03, 0.01, 0.08, 0.17, 0.75, and 1.21mg/L dissolved Zn ions measured) until reaching free swimming stage. Exposure to ZnO NP suspensions and their respective centrifuged supernatants caused similar hatching delay, but did not cause larval mortality or malformation. Larval activity level, mean velocity, and maximum velocity were altered in the groups exposed to high concentrations of ZnO NP (5-10mg/L) but not in the larvae exposed to the supernatants. To evaluate possible mechanism of observed effects caused by ZnO NP, we also manipulated the antioxidant environment by co-exposure to an antioxidant compound (N-acetylcysteine, NAC) or an antioxidant molecule suppressor (buthionine sulfoximine, BSO) with 5mg/L ZnO NP. Co-exposure to NAC did not alter the effects of ZnO NP on hatchability, but co-exposure to BSO caused further hatching delay. For larval locomotor activity, co-exposure to NAC rescued the behavioral effect caused by ZnO NP, but co-exposure to BSO did not exacerbate the effect. Our data indicated that toxicity of ZnO NP cannot be solely explained by dissolved Zn ions, and oxidative stress may involve in ZnO NP toxicity. PMID:24424259

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

    PubMed

    Kinnberg, Karin L; Petersen, Gitte I; Albrektsen, Mette; Minghlani, Mita; Awad, Suad Mohamud; Holbech, Bente F; Green, John W; Bjerregaard, Poul; Holbech, Henrik

    2015-12-01

    The chemical ultraviolet (UV) filter benzophenone-3 (BP-3) is suspected to be an endocrine disruptor based on results from in vitro and in vivo testing. However, studies including endpoints of endocrine adversity are lacking. The present study investigated the potential endocrine-disrupting effects of BP-3 in zebrafish (Danio rerio) in the Fish Sexual Development Test (Organisation for Economic Co-operation and Development TG 234) and a 12-d adult male zebrafish study. In TG 234, exposure from 0 d to 60 d posthatch caused a monotone dose-dependent skewing of the phenotypic sex ratio toward fewer males and more female zebrafish (no observed effect concentration [NOEC]: 191 μg/L, lowest observed effect concentration [LOEC]: 388 μg/L). Besides, gonad maturation was affected in both female fish (NOEC 191 μg/L, LOEC 388 μg/L) and male fish (NOEC 388 μg/L, LOEC 470 μg/L). Exposure to BP-3 did not affect the vitellogenin concentration in TG 234. After 12 d exposure of adult male zebrafish, a slight yet significant increase in the vitellogenin concentration was observed at 268 μg/L but not at 63 μg/L and 437 μg/L BP-3. Skewing of the sex ratio is a marker of an endocrine-mediated mechanism as well as a marker of adversity, and therefore the conclusion of the present study is that BP-3 is an endocrine-disrupting chemical in accordance with the World Health Organization's definition. PMID:26118430

  3. Characterization of Snakehead Rhabdovirus Infection in Zebrafish (Danio rerio)†

    PubMed Central

    Phelan, Peter E.; Pressley, Meagan E.; Witten, P. Eckhard; Mellon, Mark T.; Blake, Sharon; Kim, Carol H.

    2005-01-01

    The zebrafish, Danio rerio, has become recognized as a valuable model for the study of development, genetics, and toxicology. Recently, the zebrafish has been recognized as a useful model for infectious disease and immunity. In this study, the pathogenesis and antiviral immune response of zebrafish to experimental snakehead rhabdovirus (SHRV) infection was characterized. Zebrafish 24 h postfertilization to 30 days postfertilization were susceptible to infection by immersion in 106 50% tissue culture infective doses (TCID50) of SHRV/ml, and adult zebrafish were susceptible to infection by intraperitoneal (i.p.) injection of 105 TCID50 of SHRV/ml. Mortalities exceeded 40% in infected fish, and clinical presentation of infection included petechial hemorrhaging, redness of the abdomen, and erratic swim behavior. Virus reisolation and reverse transcription-PCR analysis of the viral nucleocapsid gene confirmed the presence of SHRV. Histological sections of moribund embryonic and juvenile fish revealed necrosis of the pharyngeal epithelium and liver, in addition to congestion of the swim bladder by cell debris. Histopathology in adult fish injected i.p. was confined to the site of injection. The antiviral response in zebrafish was monitored by quantitative real-time PCR analysis of zebrafish interferon (IFN) and Mx expression. IFN and Mx levels were elevated in zebrafish exposed to SHRV, although expression and intensity differed with age and route of infection. This study is the first to examine the pathogenesis of SHRV infection in zebrafish. Furthermore, this study is the first to describe experimental infection of zebrafish embryos with a viral pathogen, which will be important for future experiments involving targeted gene disruption and forward genetic screens. PMID:15650208

  4. Novel function of vitamin E in regulation of zebrafish (Danio rerio) brain lysophospholipids discovered using lipidomics.

    PubMed

    Choi, Jaewoo; Leonard, Scott W; Kasper, Katherine; McDougall, Melissa; Stevens, Jan F; Tanguay, Robert L; Traber, Maret G

    2015-06-01

    We hypothesized that brains from vitamin E-deficient (E-) zebrafish (Danio rerio) would undergo increased lipid peroxidation because they contain highly polyunsaturated fatty acids, thus susceptible lipids could be identified. Brains from zebrafish fed for 9 months defined diets without (E-) or with (E+) added vitamin E (500 mg RRR-α-tocopheryl acetate per kilogram diet) were studied. Using an untargeted approach, 1-hexadecanoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine [DHA-PC 38:6, PC 16:0/22:6]was the lipid that showed the most significant and greatest fold-differences between groups. DHA-PC concentrations were approximately 1/3 lower in E- (4.3 ± 0.6 mg/g) compared with E+ brains (6.5 ± 0.9 mg/g, mean ± SEM, n = 10 per group, P = 0.04). Using lipidomics, 155 lipids in brain extracts were identified. Only four phospholipids (PLs) were different (P < 0.05) between groups; they were lower in E- brains and contained DHA with DHA-PC 38:6 at the highest abundances. Moreover, hydroxy-DHA-PC 38:6 was increased in E- brains (P = 0.0341) supporting the hypothesis of DHA peroxidation. More striking was the depletion in E- brains of nearly 60% of 19 different lysophospholipids (lysoPLs) (combined P = 0.0003), which are critical for membrane PL remodeling. Thus, E- brains contained fewer DHA-PLs, more hydroxy-DHA-PCs, and fewer lysoPLs, suggesting that lipid peroxidation depletes membrane DHA-PC and homeostatic mechanisms to repair the damage resulting in lysoPL depletion. PMID:25855633

  5. Molecular cloning and functional analysis of zebrafish (Danio rerio) chemokine genes.

    PubMed

    Chen, Li-Chen; Chen, Jyh-Yih; Hour, Ai-Ling; Shiau, Chyuan-Yuan; Hui, Cho-Fat; Wu, Jen-Leih

    2008-12-01

    Chemokines control leukocyte trafficking which plays important roles in resistance to pathogenic infection. Five CXC chemokines have been reported in the zebrafish (Danio rerio) in GenBank, and herein we named them CXC-46, -56, -64, -66, and scyba. Through RT-PCR for cloning and sequencing these chemokines, the cDNA sequences of CXC-46, -56, -64, and -66 of zebrafish were determined, and it was found that the cDNA sequences were the same as those published in GenBank. Phylogenetic analysis revealed that zebrafish scyba is closest to the CXCL14 subgroup, CXC-46 is closest to the human CCL25 and catfish CXCL-2-like gene, and CXC-56, -64, and -66 are closest to the catfish CXCL10 subgroup. Further study of the tissue-specific, lipopolysaccharide (LPS) stimulation-specific, and polyinosinic-polycytidylic acid (poly I:C) stimulation-specific expressions of these five zebrafish CXC chemokine messenger (m)RNAs were determined by a comparative reverse-transcription polymerase chain reaction (RT-PCR). The RT-PCR revealed a high level of constitutive expression of CXC-56 in many tissues including the eyes, fins, heart, liver, muscles, and skin. Starvation had significant effects on the gene expressions of several zebrafish CXC chemokines including CXC-56, -64, -66, and scyba compared to the control group. Zebrafish CXC chemokines showed a concave pattern of expression after stimulation with LPS. Following poly I:C treatment of between 0.1 and 10 g/fish, dose-dependent effects were revealed. Temperature and acid-base conditions affected these zebrafish chemokines by increasing their induction compared to the control group, except for CXC-64 which exhibited no significant differences in either condition. Furthermore, these novel research results indicate that chemokines can be markers of different experimental conditions. PMID:18778789

  6. Cloning of a functional 25-hydroxyvitamin D-1α-hydroxylase in zebrafish (Danio rerio)

    PubMed Central

    Chun, Rene F.; Blatter, Elizabeth; Elliott, Stephanie; Fitz-Gibbon, Sorel; Rieger, Sandra; Sagasti, Alvaro; Adams, John S.; Hewison, Martin

    2015-01-01

    Activation of precursor 25-hydroxyvitamin D3 (25D) to hormonal 1,25-dihydroxyvitamin D3 (1,25D) is a pivotal step in vitamin D physiology, catalyzed by the enzyme 25-hydroxyvitamin D-1α-hydroxylase (1α-hydroxylase). To establish new models for assessing the physiological importance of the 1α-hydroxylase-25D-axis, we used Danio rerio (zebrafish) to characterize expression and biological activity of the gene for 1α-hydroxylase (cyp27b1). Treatment of day 5 zebrafish larvae with inactive 25D (5-150 nM) or active 1,25D (0.1-10 nM) induced dose responsive expression (15-95 fold) of the vitamin D-target gene cyp24a1 relative to larvae treated with vehicle, suggesting the presence of Cyp27b1 activity. A full-length zebrafish cyp27b1 cDNA was then generated using RACE and RT-PCR methods. Sequencing of the resulting clone revealed an open reading frame encoding a protein of 505 amino acids with 54% identity to human CYP27B1. Transfection of a cyp27b1 expression vector into HKC-8, a human kidney proximal tubular epithelial cell line, enhanced intracrine metabolism of 25D to 1,25D resulting in greater than 2-fold induction of CYP24A1 mRNA expression and a 25-fold increase in 1,25D production compared to empty vector. These data indicate that we have cloned a functional zebrafish CYP27B1, representing a phylogenetically distant branch from mammals of this key enzyme in vitamin D metabolism. Further analysis of cyp27b1 expression and activity in zebrafish may provide new perspectives on the biological importance of 25D metabolism. PMID:25290078

  7. The flexural stiffness of superficial neuromasts in the zebrafish (Danio rerio) lateral line.

    PubMed

    McHenry, Matthew J; van Netten, Sietse M

    2007-12-01

    Superficial neuromasts are structures that detect water flow on the surface of the body of fish and amphibians. As a component of the lateral line system, these receptors are distributed along the body, where they sense flow patterns that mediate a wide variety of behaviors. Their ability to detect flow is governed by their structural properties, yet the micromechanics of superficial neuromasts are not well understood. The aim of this study was to examine these mechanics in zebrafish (Danio rerio) larvae by measuring the flexural stiffness of individual neuromasts. Each neuromast possesses a gelatinous cupula that is anchored to hair cells by kinocilia. Using quasi-static bending tests of the proximal region of the cupula, we found that flexural stiffness is proportional to the number of hair cells, and consequently the number of kinocilia, within a neuromast. From this relationship, the flexural stiffness of an individual kinocilium was found to be 2.4 x 10(-20) N m2. Using this value, we estimate that the 11 kinocilia in an average cupula generate more than four-fifths of the total flexural stiffness in the proximal region. The relatively minor contribution of the cupular matrix may be attributed to its highly compliant material composition (Young's modulus of approximately 21 Pa). The distal tip of the cupula is entirely composed of this material and is consequently predicted to be at least an order of magnitude more flexible than the proximal region. These findings suggest that the transduction of flow by a superficial neuromast depends on structural dynamics that are dominated by the number and height of kinocilia.

  8. Selenium status affects selenoprotein expression, reproduction, and F₁ generation locomotor activity in zebrafish (Danio rerio).

    PubMed

    Penglase, Sam; Hamre, Kristin; Rasinger, Josef D; Ellingsen, Staale

    2014-06-14

    Se is an essential trace element, and is incorporated into selenoproteins which play important roles in human health. Mammalian selenoprotein-coding genes are often present as paralogues in teleost fish, and it is unclear whether the expression patterns or functions of these fish paralogues reflect their mammalian orthologues. Using the model species zebrafish (Danio rerio; ZF), we aimed to assess how dietary Se affects key parameters in Se metabolism and utilisation including glutathione peroxidase (GPX) activity, the mRNA expression of key Se-dependent proteins (gpx1a, gpx1b, sepp1a and sepp1b), oxidative status, reproductive success and F1 generation locomotor activity. From 27 d until 254 d post-fertilisation, ZF were fed diets with graded levels of Se ranging from deficient ( < 0·10 mg/kg) to toxic (30 mg/kg). The mRNA expression of gpx1a and gpx1b and GPX activity responded in a similar manner to changes in Se status. GPX activity and mRNA levels were lowest when dietary Se levels (0·3 mg/kg) resulted in the maximum growth of ZF, and a proposed bimodal mechanism in response to Se status below and above this dietary Se level was identified. The expression of the sepp1 paralogues differed, with only sepp1a responding to Se status. High dietary Se supplementation (30 mg/kg) decreased reproductive success, while the offspring of ZF fed above 0·3 mg Se/kg diet had lower locomotor activity than the other groups. Overall, the novel finding of low selenoprotein expression and activity coinciding with maximum body growth suggests that even small Se-induced variations in redox status may influence cellular growth rates. PMID:24666596

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

    PubMed

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

    2016-01-01

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

  10. EFFECT-DIRECTED ANALYSIS OF ELIZABETH RIVER POREWATER: DEVELOPMENTAL TOXICITY IN ZEBRAFISH (DANIO RERIO)

    PubMed Central

    Fang, Mingliang; Getzinger, Gordon J.; Cooper, Ellen M.; Clark, Bryan W.; Garner, Lindsey V.T.; Di Giulio, Richard T.; Ferguson, P. Lee; Stapleton, Heather M.

    2015-01-01

    In the present study, effect-directed analysis was used to identify teratogenic compounds in porewater collected from a Superfund site along the Elizabeth River estuary (VA, USA). Zebrafish (Danio rerio) exposed to the porewater displayed acute developmental toxicity and cardiac teratogenesis, presumably because of elevated sediment levels of polycyclic aromatic hydrocarbons (PAHs) from historical creosote use. Pretreatment of porewater with several physical and chemical particle removal methods revealed that colloid-bound chemicals constituted the bulk of the observed toxicity. Size-exclusive chromatography and normal-phase high-performance liquid chromatography were used to fractionate Elizabeth River porewater. Acute toxicity of porewater extracts and extract fractions was assessed as the pericardial area in embryonic zebrafish. The most toxic fraction contained several known aryl hydrocarbon receptor (AhR) agonists (e.g., 1,2-benzofluorene and 1,2-benzanthracene) and cytochrome P450 A1 (CPY1A) inhibitors (e.g., dibenzothiophene and fluoranthene). The second most toxic fraction contained known AhR agonists (e.g., benzo[a]pyrene and indeno[1,2,3-cd]pyrene). Addition of a CYP1A inhibitor, fluoranthene, increased toxicity in all active porewater fractions, suggesting synergism between several contaminants present in porewaters. The results indicate that the observed acute toxicity associated with Elizabeth River porewater results from high concentrations of AhR agonistic PAHs and mixture effects related to interactions between compounds co-occurring at the Elizabeth River site. However, even after extensive fractionation and chemical characterization, it remains plausible that some active compounds in Elizabeth River porewater remain unidentified. PMID:25196082

  11. Novel function of vitamin E in regulation of zebrafish (Danio rerio) brain lysophospholipids discovered using lipidomics

    PubMed Central

    Choi, Jaewoo; Leonard, Scott W.; Kasper, Katherine; McDougall, Melissa; Stevens, Jan F.; Tanguay, Robert L.; Traber, Maret G.

    2015-01-01

    We hypothesized that brains from vitamin E-deficient (E−) zebrafish (Danio rerio) would undergo increased lipid peroxidation because they contain highly polyunsaturated fatty acids, thus susceptible lipids could be identified. Brains from zebrafish fed for 9 months defined diets without (E−) or with (E+) added vitamin E (500 mg RRR-α-tocopheryl acetate per kilogram diet) were studied. Using an untargeted approach, 1-hexadecanoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine [DHA-PC 38:6, PC 16:0/22:6]was the lipid that showed the most significant and greatest fold-differences between groups. DHA-PC concentrations were approximately 1/3 lower in E− (4.3 ± 0.6 mg/g) compared with E+ brains (6.5 ± 0.9 mg/g, mean ± SEM, n = 10 per group, P = 0.04). Using lipidomics, 155 lipids in brain extracts were identified. Only four phospholipids (PLs) were different (P < 0.05) between groups; they were lower in E− brains and contained DHA with DHA-PC 38:6 at the highest abundances. Moreover, hydroxy-DHA-PC 38:6 was increased in E− brains (P = 0.0341) supporting the hypothesis of DHA peroxidation. More striking was the depletion in E− brains of nearly 60% of 19 different lysophospholipids (lysoPLs) (combined P = 0.0003), which are critical for membrane PL remodeling. Thus, E− brains contained fewer DHA-PLs, more hydroxy-DHA-PCs, and fewer lysoPLs, suggesting that lipid peroxidation depletes membrane DHA-PC and homeostatic mechanisms to repair the damage resulting in lysoPL depletion. PMID:25855633

  12. Presenilin1 regulates histamine neuron development and behavior in zebrafish, danio rerio.

    PubMed

    Sundvik, Maria; Chen, Yu-Chia; Panula, Pertti

    2013-01-23

    Modulatory neurotransmitters, including the histaminergic system, are essential in mediating cognitive functions affected in Alzheimer's disease (AD). The roles of disease genes associated with AD, most importantly the presenilin1 gene (psen1), are poorly understood. We studied the role of psen1 in plasticity of the brain histaminergic system using a novel psen1 mutant zebrafish, Danio rerio. We found that in psen1(-/-) zebrafish, the histaminergic system is altered throughout life. At 7 d postfertilization (dpf) the histamine neuron number was reduced in psen1(-/-) compared with wild-type (WT) fish; at 2 months of age the histamine neuron number was at the same level as that in WT fish. In 1-year-old zebrafish, the histamine neuron number was significantly increased in psen1(-/-) fish compared with WT fish. These changes in histamine neuron number were accompanied by changes in histamine-driven behaviors. Treatment with DAPT, a γ-secretase inhibitor, similarly interfered with the development of the histaminergic neurons. We also assessed the expression of γ-secretase-regulated Notch1a mRNA and β-catenin at different time points. Notch1a mRNA level was reduced in psen1(-/-) compared with WT fish, whereas β-catenin was slightly upregulated in the hypothalamus of psen1(-/-) compared with WT fish at 7 dpf. The results reveal a life-long brain plasticity in both the structure of the histaminergic system and its functions induced by altered Notch1a activity as a consequence of psen1 mutation. The new histaminergic neurons in aging zebrafish brain may arise as a result of phenotypic plasticity or represent newly differentiated stem cells.

  13. Embryonic Stage-Dependent Teratogenicity of Ketamine in Zebrafish (Danio rerio).

    PubMed

    Félix, Luís M; Serafim, Cindy; Valentim, Ana M; Antunes, Luís M; Campos, Sónia; Matos, Manuela; Coimbra, Ana M

    2016-08-15

    Ketamine, a widely used anesthetic, has been shown to have NMDA receptor dependent and independent actions during zebrafish (Danio rerio) embryogenesis. Notwithstanding, the effects of developmental toxicity and the mechanisms of ketamine action on fish embryos are still not well understood, and its implications for early vertebrate development remains to be clarified. In this work, zebrafish embryos were exposed to ketamine (0.2, 0.4, and 0.8 mg mL(-1)) in order to study the stage-developmental toxicity of this pharmaceutical. During 256-cell (2.5 h post-fertilization, hpf), 50% epiboly (5.5 hpf) and 1-4 somites (10.5 hpf), embryos were exposed to the referred ketamine concentrations for a period of 20 min and were allowed to grow until 144 hpf. Both lethal and nonlethal parameters were evaluated. Skeletal development was assessed by alcian blue and calcein staining. Additionally, the expression of the developmental genes sonic hedgehog a (shh a) and noggin 3 (nog3) was evaluated. Similar to our previous work, bone and cartilage malformations were observed after 256-cell exposure. During 50% epiboly, ketamine exposure induced concentration-dependent mortality and malformations, such as lordosis and/or kyphosis and microcephaly, namely, at higher concentrations. Conversely, exposure during 1-4 somites showed the induction of nonspecific effects with no rise in mortality. The quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed differences in shh a and nog3 expressions comparatively to the control group. Overall, this study shows that the ketamine toxic profile is developmental phase-dependent with 256-cell being the most susceptible phase. The effects observed may result from ketamine interaction with cellular signaling pathways that merits further investigation.

  14. Sexual dimorphisms in swimming behavior, cerebral metabolic activity and adrenoceptors in adult zebrafish (Danio rerio).

    PubMed

    Ampatzis, Konstantinos; Dermon, Catherine R

    2016-10-01

    Sexually dimorphic behaviors and brain sex differences, not only restricted to reproduction, are considered to be evolutionary preserved. Specifically, anxiety related behavioral repertoire is suggested to exhibit sex-specific characteristics in rodents and primates. The present study investigated whether behavioral responses to novelty, have sex-specific characteristics in the neurogenetic model organism zebrafish (Danio rerio), lacking chromosomal sex determination. For this, aspects of anxiety-like behavior (including reduced exploration, increased freezing behavior and erratic movement) of male and female adult zebrafish were tested in a novel tank paradigm and after habituation. Male and female zebrafish showed significant differences in their swimming activity in response to novelty, with females showing less anxiety spending more time in the upper tank level. When fish have habituated, regional cerebral glucose uptake, an index of neuronal activity, and brain adrenoceptors' (ARs) expression (α2-ARs and β-ARs) were determined using in vivo 2-[(14)C]-deoxyglucose methodology and in vitro neurotransmitter receptors quantitative autoradiography, respectively. Intriguingly, females exhibited higher glucose utilization than males in hypothalamic brain areas. Adrenoceptor's expression pattern was dimorphic in zebrafish telencephalic, preoptic, hypothalamic nuclei, central gray, and cerebellum, similarly to birds and mammals. Specifically, the lateral zone of dorsal telencephalon (Dl), an area related to spatial cognition, homologous to the mammalian hippocampus, showed higher α2-AR densities in females. In contrast, male cerebellum included higher densities of β-ARs in comparison to female. Taken together, our data demonstrate a well-defined sex discriminant cerebral metabolic activity and ARs' pattern in zebrafish, possibly contributing to male-female differences in the swimming behavior. PMID:27363927

  15. Identification and biochemical characterization of two functional CMP-sialic acid synthetases in Danio rerio.

    PubMed

    Schaper, Wiebke; Bentrop, Joachim; Ustinova, Jana; Blume, Linda; Kats, Elina; Tiralongo, Joe; Weinhold, Birgit; Bastmeyer, Martin; Münster-Kühnel, Anja-K

    2012-04-13

    Sialic acids (Sia) form the nonreducing end of the bulk of cell surface-expressed glycoconjugates. They are, therefore, major elements in intercellular communication processes. The addition of Sia to glycoconjugates requires metabolic activation to CMP-Sia, catalyzed by CMP-Sia synthetase (CMAS). This highly conserved enzyme is located in the cell nucleus in all vertebrates investigated to date, but its nuclear function remains elusive. Here, we describe the identification and characterization of two Cmas enzymes in Danio rerio (dreCmas), one of which is exclusively localized in the cytosol. We show that the two cmas genes most likely originated from the third whole genome duplication, which occurred at the base of teleost radiation. cmas paralogues were maintained in fishes of the Otocephala clade, whereas one copy got subsequently lost in Euteleostei (e.g. rainbow trout). In zebrafish, the two genes exhibited a distinct spatial expression pattern. The products of these genes (dreCmas1 and dreCmas2) diverged not only with respect to subcellular localization but also in substrate specificity. Nuclear dreCmas1 favored N-acetylneuraminic acid, whereas the cytosolic dreCmas2 showed highest affinity for 5-deamino-neuraminic acid. The subcellular localization was confirmed for the endogenous enzymes in fractionated zebrafish lysates. Nuclear entry of dreCmas1 was mediated by a bipartite nuclear localization signal, which seemed irrelevant for other enzymatic functions. With the current demonstration that in zebrafish two subfunctionalized cmas paralogues co-exist, we introduce a novel and unique model to detail the roles that CMAS has in the nucleus and in the sialylation pathways of animal cells.

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

    PubMed Central

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

    2016-01-01

    The combined effects of low-dose or high-dose alpha particles and depleted uranium (DU) in Zebrafish (Danio rerio) embryos were studied. Three schemes were examined—(i) [ILUL]: 0.44 mGy alpha-particle dose + 10 µg/l DU exposure, (ii) [IHUH]: 4.4 mGy alpha-particle dose + 100 µg/l DU exposure and (iii) [IHUL]: 4.4 mGy alpha-particle dose + 10 µg/l DU exposure—in which Zebrafish embryos were irradiated with alpha particles at 5 h post fertilization (hpf) and/or exposed to uranium at 5–6 hpf. The results were also compared with our previous work, which studied the effects of [ILUH]: 0.44 mGy alpha-particle dose + 100 µg/l DU exposure. When the Zebrafish embryos developed to 24 hpf, the apoptotic signals in the entire embryos, used as the biological endpoint for this study, were quantified. Our results showed that [ILUL] and [IHUL] led to antagonistic effects, whereas [IHUH] led to an additive effect. The effect found for the previously studied case of [ILUH] was difficult to define because it was synergistic with reference to the 100 µg/l DU exposure, but it was antagonistic with reference to the 0.44 mGy alpha-particle dose. All the findings regarding the four different schemes showed that the combined effects critically depended on the dose response to each individual stressor. We also qualitatively explained these findings in terms of promotion of early death of cells predisposed to spontaneous transformation by alpha particles, interacting with the delay in cell death resulting from various concentrations of DU exposure. PMID:26937024

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

    PubMed

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

    2016-03-01

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

  18. FXYD11 mediated modulation of Na(+)/K(+)-ATPase activity in gills of the brackish medaka (Oryzias dancena) when transferred to hypoosmotic or hyperosmotic environments.

    PubMed

    Chang, Chia-Hao; Yang, Wen-Kai; Lin, Chia-Hao; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

    2016-04-01

    FXYD proteins regulate Na(+)/K(+)-ATPase (NKA), which is a primary active pump that provides the driving force that triggers osmoregulatory systems in teleosts. To explore the regulatory mechanisms between FXYD and NKA in euryhaline teleosts, the expression of NKA (mRNA, protein, and activity) and FXYD11 and their interaction were examined in the gills of brackish medaka (Oryzias dancena) when transferred from brackish water (BW; 15‰) to fresh water (FW) or seawater (SW; 35‰). The mRNA expression of Odfxyd11 and Odnka-α was elevated 48h post-hypoosmotic transfer. Moreover, FXYD11 protein and NKA activity were upregulated 12h after transfer to FW. When transferred to SW, the protein abundance of FXYD11 and the NKA α-subunit did not show apparent changes, while Odfxyd11 and Odnka-α mRNA expression and NKA activity increased significantly 12h and 1h post-transfer, respectively. To clarify the FXYD11 mechanisms involved in modulating NKA activity via their interaction, co-immunoprecipitation was further applied to O. dancena gills. The results revealed that the levels of protein-protein interaction between branchial NKA and FXYD11 increased acutely 12h after the transfer from BW to FW. However, immediate upregulation of NKA activity 1h following post-exposure to SW, without the elevation of protein-protein interaction levels, was found. Hence, branchial NKA activity of O. dancena was suggested to be rapidly regulated by FXYD11 interaction with NKA when acclimated to hypoosmotic environments. To the best of our knowledge, this is the first study that focuses on the efficacy of interactions between FXYD11 and NKA in the gills of euryhaline teleosts.

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

    PubMed

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

    2016-05-01

    Magnetic exfoliated vermiculite is a synthetic nanocomposite that quickly and efficiently absorbs organic compounds such as oil from water bodies. It was developed primarily to mitigate pollution, but the possible adverse impacts of its application have not yet been evaluated. In this context, the acute toxicity of magnetic exfoliated vermiculite and exfoliated vermiculite was herein assessed by genotoxic and histopathological biomarkers in zebrafish (Danio rerio). DNA fragmentation was statistically significant for all groups exposed to the magnetic exfoliated vermiculite and for fish exposed to the highest concentration (200mg/L) of exfoliated vermiculite, whereas the micronucleus frequency, nuclear abnormalities and histopathological alterations were not statistically significant for the fish exposed to these materials. In the intestinal lumen, epithelial cells and goblet cells, we found the presence of magnetic exfoliated vermiculite and exfoliated vermiculite, but no alterations or presence of the materials-test in the gills or liver were observed. Our findings suggest that the use of magnetic exfoliated vermiculite and exfoliated vermiculite during standard ecotoxicological assays caused DNA damage in D. rerio, whose alterations may be likely to be repaired, indicating that the magnetic nanoparticles have the ability to promote genotoxic damage, such as DNA fragmentation, but not mutagenic effects. PMID:26878635

  20. Cardiovascular and respiratory developmental plasticity under oxygen depleted environment and in genetically hypoxic zebrafish (Danio rerio).

    PubMed

    Yaqoob, Nadeem; Schwerte, Thorsten

    2010-08-01

    Known vertebrate response to low oxygen concentration include change in carbohydrate metabolism, increase in nitric oxide, stimulation of red blood cell and hemoglobin production and induction of gene expression for glycolytic enzymes and hormones. Also, extreme hypoxia plays main role in pathological studies of cardiac dysfunction. The morphological and physiological developmental studies of the cardiovascular system under low oxygen are important as it is directly related to oxygen supply and consumption. Furthermore, cardiac function demands high energy during system development and thus it is most likely to be affected by hypoxia. Zebrafish (Danio rerio) can act as a model organism for oxygen demand management study as in natural environment, due to ecological disturbances, it is exposed to changes in oxygen concentrations routinely and thus would have natural ability to cope with it for survival. We have studied, in zebrafish, i) cardiovascular flexibility under extreme hypoxia (PO(2)=20 Torr, 3 kPa) at 3-10 dpf (days post-fertilization), ii) cardiac re-animation in normoxia (PO(2)=152 Torr, 20 kPa) after 90 min of anoxia (PO(2)=0 Torr, 0 kPa)-induced suspended animation at 4 dpf and iii) oxygen consumption in 8 dpf von Hippel-Lindau (vhl(-)(/)(-)) mutant that exhibits an artificial hypoxic response under normoxic conditions. In hypoxic fish, cardiac output, stroke volume and end-diastolic volume were elevated while intersegmental blood vessels vascularization index at 6 dpf and at 10 dpf was 22% and 11% higher respectively as compared to the normoxic fish. The heart rate in hypoxic fish was lower until 6 dpf and then showed an elevated trend. There was no significant difference in body length between the hypoxic and normoxic individuals. The observed changes may have enhanced the performance of the cardiovascular system for oxygen uptake. We also report for the first time that the post-anoxia re-animated heart rate returns to normal after 48h. Measurement of

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

    PubMed

    Gore, Matthew; Burggren, Warren W

    2012-01-01

    Swimming stamina in adult fish is heritable, it is unknown if inherited traits that support enhanced swimming stamina in offspring appear only in juveniles and/or adults, or if these traits actually appear earlier in the morphologically quite different larvae. To answer this question, mature adult zebrafish (Danio rerio) were subjected to a swimming performance test that allowed separation into low swimming stamina or high swimming stamina groups. Adults were then bred within their own performance groups. Larval offspring from each of the two groups, designated high (L(HSD)) and low stamina-derived larvae (L(LSD)), were then reared at 27°C in aerated water (21% O(2)). Routine (f(H),r) and active (f(H),a) heart rate, and routine [Formula: see text] and active [Formula: see text] mass-specific oxygen consumption were recorded from 5 days post fertilization (dpf) through 21 dpf, and gross cost of transport and factorial aerobic metabolic scope were derived from [Formula: see text] measurements. Heart rate generally ranged between 150 and 225 bpm in both L(HSD) and L(LSD) populations. However, significant (P < 0.05) differences existed between the L(LSD) and L(HSD) populations at 5 and 14 dpf in f(H),r and at days 10 and 15 dpf in f(H),a. [Formula: see text] was 0.04-0.32 μmol mg(-1) h(-1), while [Formula: see text] was 0.2-1.2 μmol mg(-1) h(-1). Significant (P < 0.05) differences between the L(LSD) and L(HSD) populations in [Formula: see text] occurred at 7, 10, and 21 dpf and in [Formula: see text] at 7 dpf. Gross cost of transport was ∼6-10 μmol O(2)·μg(-1) m(-1) at 5 dpf, peaking at 14-19 μmol O(2) μg(-1) m(-1) at 7-10 dpf, before falling again to 5-6 μmol O(2) μg(-1) m(-1) at 21 dpf, with gross cost of transport significantly higher in the L(LSD) population at 7 dpf. Collectively, these data indicate that inherited physiological differences known to contribute to enhanced stamina in adult

  2. Trophic transfer of differently functionalized zinc oxide nanoparticles from crustaceans (Daphnia magna) to zebrafish (Danio rerio).

    PubMed

    Skjolding, L M; Winther-Nielsen, M; Baun, A

    2014-12-01

    The potential uptake and trophic transfer of nanoparticles (NP) is not well understood so far and for ZnO NP the data presented in peer-reviewed literature is limited. In this paper the influence of surface functionalization on the uptake and depuration behavior of ZnO NP, ZnO-OH NP and ZnO-octyl NP in D. magna was studied. Bulk ZnO particles (≤5 μm) and ZnCl2 were used as references for uptake of particles and dissolved species of Zn, respectively. Furthermore, the trophic transfer of ZnO NP and ZnO-octyl NP from daphnids (Daphnia magna) to zebra fish (Danio rerio) was studied. For ZnO NP and ZnO-octyl NP fast uptakes in D. magna were observed, whereas no measurable uptake took place for ZnO-OH NP. Lower body burden of ZnCl2 was found compared to both ZnO NP and ZnO-octyl. Contrary, the body burden for bulk ZnO was higher than that of ZnO NP but lower than ZnO-octyl. The higher body burdens found for functionalized ZnO-octyl NP than for non-functionalized ZnO NP showed that that the functionalization of the NP has a high influence on the uptake and depuration behavior. Though no mortality was observed, the resulting body burdens were 9.6 times (ZnO NP) and 47 times (ZnO-octyl NP) higher than toxic levels reported for zinc in D. magna. Consequently, the zinc recovered in the animals was not solely due to soluble zinc, but agglomerates/aggregates of ZnO NP or ZnO-octyl NP contributed to the body burdens. The trophic transfer study showed uptake of both ZnO NP and ZnO-octyl NP reaching more than tenfold higher levels than those obtained through aqueous exposure in other studies. This study contributes to expand the available data on uptake behavior of differently functionalized ZnO NP in D. magna and the potential trophic transfer from zooplankton to fish.

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

    SciTech Connect

    Blüthgen, Nancy; Zucchi, Sara; Fent, Karl

    2012-09-01

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

  4. Danio rerio embryos on Prozac - Effects on the detoxification mechanism and embryo development.

    PubMed

    Cunha, V; Rodrigues, P; Santos, M M; Moradas-Ferreira, P; Ferreira, M

    2016-09-01

    In the past decade the presence of psychopharmaceuticals, including fluoxetine (FLU), in the aquatic environment has been associated with the increasing trend in human consumption of these substances. Aquatic organisms are usually exposed to chronic low doses and, therefore, risk assessments should evaluate the effects of these compounds in non-target organisms. Teleost fish possess an array of active defence mechanisms to cope with the deleterious effects of xenobiotics. These include ABC transporters, phase I and II of cellular detoxification and oxidative stress enzymes. Hence, the present study aimed at characterising the effect of FLU on embryo development of the model teleost zebrafish (Danio rerio) concomitantly with changes in the detoxification mechanisms during early developmental phases. Embryos were exposed to different concentrations of FLU (0.0015, 0.05, 0.1, 0.5 and 0.8μM) for 80hours post fertilization. Development was screened and the impact in the transcription of key genes, i.e., abcb4, abcc1, abcc2, abcg2, cyp1a, cyp3a65, gst, sod, cat, ahr, pxr, pparα, pparβ, pparγ, rxraa, rxrab, rxrbb, rxrga, rxrgb, raraa, rarab, rarga evaluated. In addition, accumulation assays were performed to measure the activity of ABC proteins and antioxidant enzymes (CAT and Cu/ZnSOD) after exposure to FLU. Embryo development was disrupted at the lowest FLU concentration tested (0.0015μM), which is in the range of concentrations found in WWTP effluents. Embryos exposed to higher concentrations of FLU decreased Cu/Zn SOD, and increased CAT (0.0015 and 0.5μM) enzymatic activity. Exposure to higher concentrations of FLU decreased the expression of most genes belonging to the detoxification system and upregulated cat at 0.0015μM of FLU. Most of the tested concentrations downregulated pparα, pparβ, pparγ, and raraa, rxraa, rxrab, rxrbb rxrgb and ahr gene expression while pxr was significantly up regulated at all tested concentrations. In conclusion, this study

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

    PubMed Central

    Gore, Matthew; Burggren, Warren W.

    2012-01-01

    Swimming stamina in adult fish is heritable, it is unknown if inherited traits that support enhanced swimming stamina in offspring appear only in juveniles and/or adults, or if these traits actually appear earlier in the morphologically quite different larvae. To answer this question, mature adult zebrafish (Danio rerio) were subjected to a swimming performance test that allowed separation into low swimming stamina or high swimming stamina groups. Adults were then bred within their own performance groups. Larval offspring from each of the two groups, designated high (LHSD) and low stamina-derived larvae (LLSD), were then reared at 27°C in aerated water (21% O2). Routine (fH,r) and active (fH,a) heart rate, and routine (Ṁo2,r) and active (Ṁo2,a) mass-specific oxygen consumption were recorded from 5 days post fertilization (dpf) through 21 dpf, and gross cost of transport and factorial aerobic metabolic scope were derived from Ṁo2 measurements. Heart rate generally ranged between 150 and 225 bpm in both LHSD and LLSD populations. However, significant (P < 0.05) differences existed between the LLSD and LHSD populations at 5 and 14 dpf in fH,r and at days 10 and 15 dpf in fH,a. Ṁo2,r was 0.04–0.32 μmol mg−1 h−1, while Ṁo2,a was 0.2–1.2 μmol mg−1 h−1. Significant (P < 0.05) differences between the LLSD and LHSD populations in Ṁo2,r occurred at 7, 10, and 21 dpf and in Ṁo2,a at 7 dpf. Gross cost of transport was ∼6–10 μmol O2·μg−1 m−1 at 5 dpf, peaking at 14–19 μmol O2 μg−1 m−1 at 7–10 dpf, before falling again to 5–6 μmol O2 μg−1 m−1 at 21 dpf, with gross cost of transport significantly higher in the LLSD population at 7 dpf. Collectively, these data indicate that inherited physiological differences known to contribute to enhanced stamina in adult parents also appear in their larval offspring well before attainment of juvenile or adult features. PMID

  6. 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 . PMID:26859625

  7. Small fish models for identifying and assessing the effects of endocrine-disrupting chemicals.

    PubMed

    Ankley, Gerald T; Johnson, Rodney D

    2004-01-01

    Endocrine-disrupting chemicals (EDCs), particularly those that affect the hypothalamic-pituitary-gonadal (HPG) axis of vertebrates, have become a focus of regulatory screening and testing throughout the world. Small fish species, principally the fathead minnow (Pimephales promelas), Japanese medaka (Oryzias latipes), and zebrafish (Danio rerio), are used as model organisms for several of these testing programs. Fish are appropriate models for testing EDCs, not only from the perspective of existing ecological impacts, but also in terms of species extrapolation. Specifically, there is a significant degree of conservation of basic aspects of the HPG axis across vertebrates, which provides a technically robust basis for using results from fish tests to predict likely modes/mechanisms of action of potential EDCs in other vertebrates. Different experimental designs/endpoints for partial- and full-life cycle tests with fish that enable a consideration of a broad range of EDCs are described. Examples of results with specific chemicals in tests with the fathead minnow, medaka, and zebrafish are presented and discussed in terms of sensitivity and specificity for different classes of EDCs.

  8. Comparative epigenomics in distantly related teleost species identifies conserved cis-regulatory nodes active during the vertebrate phylotypic period.

    PubMed

    Tena, Juan J; González-Aguilera, Cristina; Fernández-Miñán, Ana; Vázquez-Marín, Javier; Parra-Acero, Helena; Cross, Joe W; Rigby, Peter W J; Carvajal, Jaime J; Wittbrodt, Joachim; Gómez-Skarmeta, José L; Martínez-Morales, Juan R

    2014-07-01

    The complex relationship between ontogeny and phylogeny has been the subject of attention and controversy since von Baer's formulations in the 19th century. The classic concept that embryogenesis progresses from clade general features to species-specific characters has often been revisited. It has become accepted that embryos from a clade show maximum morphological similarity at the so-called phylotypic period (i.e., during mid-embryogenesis). According to the hourglass model, body plan conservation would depend on constrained molecular mechanisms operating at this period. More recently, comparative transcriptomic analyses have provided conclusive evidence that such molecular constraints exist. Examining cis-regulatory architecture during the phylotypic period is essential to understand the evolutionary source of body plan stability. Here we compare transcriptomes and key epigenetic marks (H3K4me3 and H3K27ac) from medaka (Oryzias latipes) and zebrafish (Danio rerio), two distantly related teleosts separated by an evolutionary distance of 115-200 Myr. We show that comparison of transcriptome profiles correlates with anatomical similarities and heterochronies observed at the phylotypic stage. Through comparative epigenomics, we uncover a pool of conserved regulatory regions (≈700), which are active during the vertebrate phylotypic period in both species. Moreover, we show that their neighboring genes encode mainly transcription factors with fundamental roles in tissue specification. We postulate that these regulatory regions, active in both teleost genomes, represent key constrained nodes of the gene networks that sustain the vertebrate body plan.

  9. Whole genome data for omics-based research on the self-fertilizing fish Kryptolebias marmoratus.

    PubMed

    Rhee, Jae-Sung; Lee, Jae-Seong

    2014-08-30

    Genome resources have advantages for understanding diverse areas such as biological patterns and functioning of organisms. Omics platforms are useful approaches for the study of organs and organisms. These approaches can be powerful screening tools for whole genome, proteome, and metabolome profiling, and can be used to understand molecular changes in response to internal and external stimuli. This methodology has been applied successfully in freshwater model fish such as the zebrafish Danio rerio and the Japanese medaka Oryzias latipes in research areas such as basic physiology, developmental biology, genetics, and environmental biology. However, information is still scarce about model fish that inhabit brackish water or seawater. To develop the self-fertilizing killifish Kryptolebias marmoratus as a potential model species with unique characteristics and research merits, we obtained genomic information about K. marmoratus. We address ways to use these data for genome-based molecular mechanistic studies. We review the current state of genome information on K. marmoratus to initiate omics approaches. We evaluate the potential applications of integrated omics platforms for future studies in environmental science, developmental biology, and biomedical research. We conclude that information about the K. marmoratus genome will provide a better understanding of the molecular functions of genes, proteins, and metabolites that are involved in the biological functions of this species. Omics platforms, particularly combined technologies that make effective use of bioinformatics, will provide powerful tools for hypothesis-driven investigations and discovery-driven discussions on diverse aspects of this species and on fish and vertebrates in general.

  10. Comparative epigenomics in distantly related teleost species identifies conserved cis-regulatory nodes active during the vertebrate phylotypic period

    PubMed Central

    Tena, Juan J.; González-Aguilera, Cristina; Fernández-Miñán, Ana; Vázquez-Marín, Javier; Parra-Acero, Helena; Cross, Joe W.; Rigby, Peter W.J.; Carvajal, Jaime J.; Wittbrodt, Joachim; Gómez-Skarmeta, José L.; Martínez-Morales, Juan R.

    2014-01-01

    The complex relationship between ontogeny and phylogeny has been the subject of attention and controversy since von Baer’s formulations in the 19th century. The classic concept that embryogenesis progresses from clade general features to species-specific characters has often been revisited. It has become accepted that embryos from a clade show maximum morphological similarity at the so-called phylotypic period (i.e., during mid-embryogenesis). According to the hourglass model, body plan conservation would depend on constrained molecular mechanisms operating at this period. More recently, comparative transcriptomic analyses have provided conclusive evidence that such molecular constraints exist. Examining cis-regulatory architecture during the phylotypic period is essential to understand the evolutionary source of body plan stability. Here we compare transcriptomes and key epigenetic marks (H3K4me3 and H3K27ac) from medaka (Oryzias latipes) and zebrafish (Danio rerio), two distantly related teleosts separated by an evolutionary distance of 115–200 Myr. We show that comparison of transcriptome profiles correlates with anatomical similarities and heterochronies observed at the phylotypic stage. Through comparative epigenomics, we uncover a pool of conserved regulatory regions (≈700), which are active during the vertebrate phylotypic period in both species. Moreover, we show that their neighboring genes encode mainly transcription factors with fundamental roles in tissue specification. We postulate that these regulatory regions, active in both teleost genomes, represent key constrained nodes of the gene networks that sustain the vertebrate body plan. PMID:24709821

  11. Description of Embryonic Development of Spotted Green Pufferfish (Tetraodon nigroviridis)

    PubMed Central

    Zaucker, Andreas; Bodur, Türker; Roest Crollius, Hugues; Hadzhiev, Yavor; Gehrig, Jochen; Loosli, Felix; Watson, Craig

    2014-01-01

    Abstract Pufferfish species of the Tetraodontidae family carry the smallest genomes among vertebrates. Their compressed genomes are thought to be enriched for functional DNA compared to larger vertebrate genomes, and they are important models for comparative genomics. The significance of pufferfish as model organisms in comparative genomics is due to the availability of two sequenced genomes, that of spotted green pufferfish (Tetraodon nigroviridis) and fugu (Takifugu rubripes). However, there is only a very limited utilization of pufferfish as an experimental model organism, due to the lack of established husbandry and developmental genetics protocols. In this study, we provide the first description of the normal embryonic development of Tetraodon nigroviridis. Embryos were obtained by in vitro fertilization of eggs, and subsequent development was monitored by brightfield microscopy at constant temperature. Tetraodon development was divided into distinct stages based on diagnostic morphological features, which were adopted from published literature on normal development of other fish species like medaka (Oryzias latipes), zebrafish (Danio rerio), and fugu. Tetraodon embryos show more similar morphologies to medaka than to zebrafish, reflecting its phylogenetic position. The early developmental stage series described in this study forms the foundation for the utilization of tetraodon as an experimental model organism for comparative developmental studies. PMID:25243591

  12. Concentration-dependent toxicity effect of SDBS on swimming behavior of freshwater fishes.

    PubMed

    Zhang, Ying; Ma, Jing; Zhou, Siyun; Ma, Fang

    2015-07-01

    Sodium dodecyl benzene sulfonate (SDBS) is a kind of widely used anionic surfactant and its discharge may pose potential risk to the receiving aquatic ecosystem. The aim of our study is to investigate the toxic effect of SDBS on fish swimming behavior quantitatively, followed by examination whether there are significant differences of swimming behavior among applied fish species (i.e. zebra fish (Danio rerio), Japanese medaka (Oryzias latipes) and red carp (Cyprinus carpio)). The swimming speed and vertical position were analyzed after the fish exposed to SDBS aiming to reflect the toxicity of SDBS on fish. Our results showed that the swimming behavior of three fishes was significantly affected by SDBS, although there were slight differences of swimming pattern changes among three fish species when they exposed to the same concentration of SDBS. It could be seen that red carp, one of the native fish species in China, can be used as a model fish to reflect the water quality changes as well as zebra fish and Japanese medaka which are commonly used as model fishes. Our study also illustrated that the swimming behavior monitoring may have a good application prospect in pre-warning of water quality.

  13. Gender-specific modulation of immune system complement gene expression in marine medaka Oryzias melastigma following dietary exposure of BDE-47.

    PubMed

    Ye, Roy R; Lei, Elva N Y; Lam, Michael H W; Chan, Alice K Y; Bo, Jun; van de Merwe, Jason P; Fong, Amy C C; Yang, Michael M S; Lee, J S; Segner, Helmut E; Wong, Chris K C; Wu, Rudolf S S; Au, Doris W T

    2011-08-01

    BDE-47 is one of the most widely found congeners of PBDEs in marine environments. The potential immunomodulatory effects of BDE-47 on fish complement system were studied using the marine medaka Oryzias melastigma as a model fish. Three-month-old O. melastigma were subjected to short-term (5 days) and long-term (21 days) exposure to two concentrations of BDE-47 (low dose at 290 ± 172 ng/day; high dose at 580 ± 344 ng/day) via dietary uptake of BDE-47 encapsulated in Artemia nauplii. Body burdens of BDE-47 and other metabolic products were analyzed in the exposed and control fish. Only a small amount of debrominated product, BDE-28, was detected, while other metabolic products were all under detection limit. Transcriptional expression of six major complement system genes involved in complement activation: C1r/s (classical pathway), MBL-2 (lectin pathway), CFP (alternative pathway), F2 (coagulation pathway), C3 (the central component of complement system), and C9 (cell lysis) were quantified in the liver of marine medaka. Endogenous expression of all six complement system genes was found to be higher in males than in females (p < 0.05). Upon dietary exposure of marine medaka to BDE-47, expression of all six complement genes were downregulated in males at day 5 (or longer), whereas in females, MBl-2, CFP, and F2 mRNAs expression were upregulated, but C3 and C9 remained stable with exposure time and dose. A significant negative relationship was found between BDE-47 body burden and mRNA expression of C1r/s, CFP, and C3 in male fish (r = -0.8576 to -0.9447). The above findings on changes in complement gene expression patterns indicate the complement system may be compromised in male O. melastigma upon dietary exposure to BDE-47. Distinct gender difference in expression of six major complement system genes was evident in marine medaka under resting condition and dietary BDE-47 challenge. The immunomodulatory effects of BDE-47 on transcriptional

  14. Gender-specific modulation of immune system complement gene expression in marine medaka Oryzias melastigma following dietary exposure of BDE-47.

    PubMed

    Ye, Roy R; Lei, Elva N Y; Lam, Michael H W; Chan, Alice K Y; Bo, Jun; van de Merwe, Jason P; Fong, Amy C C; Yang, Michael M S; Lee, J S; Segner, Helmut E; Wong, Chris K C; Wu, Rudolf S S; Au, Doris W T

    2011-08-01

    BDE-47 is one of the most widely found congeners of PBDEs in marine environments. The potential immunomodulatory effects of BDE-47 on fish complement system were studied using the marine medaka Oryzias melastigma as a model fish. Three-month-old O. melastigma were subjected to short-term (5 days) and long-term (21 days) exposure to two concentrations of BDE-47 (low dose at 290 ± 172 ng/day; high dose at 580 ± 344 ng/day) via dietary uptake of BDE-47 encapsulated in Artemia nauplii. Body burdens of BDE-47 and other metabolic products were analyzed in the exposed and control fish. Only a small amount of debrominated product, BDE-28, was detected, while other metabolic products were all under detection limit. Transcriptional expression of six major complement system genes involved in complement activation: C1r/s (classical pathway), MBL-2 (lectin pathway), CFP (alternative pathway), F2 (coagulation pathway), C3 (the central component of complement system), and C9 (cell lysis) were quantified in the liver of marine medaka. Endogenous expression of all six complement system genes was found to be higher in males than in females (p < 0.05). Upon dietary exposure of marine medaka to BDE-47, expression of all six complement genes were downregulated in males at day 5 (or longer), whereas in females, MBl-2, CFP, and F2 mRNAs expression were upregulated, but C3 and C9 remained stable with exposure time and dose. A significant negative relationship was found between BDE-47 body burden and mRNA expression of C1r/s, CFP, and C3 in male fish (r = -0.8576 to -0.9447). The above findings on changes in complement gene expression patterns indicate the complement system may be compromised in male O. melastigma upon dietary exposure to BDE-47. Distinct gender difference in expression of six major complement system genes was evident in marine medaka under resting condition and dietary BDE-47 challenge. The immunomodulatory effects of BDE-47 on transcriptional

  15. Early life-stage mortality in zebrafish (Danio rerio) following maternal exposure to polychlorinated biphenyls and estrogen

    SciTech Connect

    Westerlund, L.; Billsson, K.; Andersson, P.L.; Tysklind, M.; Olsson, P.E.

    2000-06-01

    In the present study, specific polychlorinated biphenyl (PCB) congeners were examined for embryo and early life stage mortality in zebrafish (Danio rerio). A set of eight PCBs and two hydroxylated PCBs and 17{beta}-estradiol were tested. Of the compounds tested, 4{prime}-OH-PCB30 (hydroxylated polychlorinated biphenyl) and PCB104 were found to be highly toxic to embryos following maternal exposure and transfer to the oocyte. It was also observed that 17{beta}-estradiol exposure resulted in a high incidence of embryo mortality. Analysis of estrogen receptor levels during embryonic development showed increased mRNA (ribonucleic acid) levels from the 1K stage to 50% epiboly. Following injection of the different compounds, the estrogen receptor mRNA levels were also analyzed in adult male fish to determine if there was a correlation between embryo mortality and estrogenicity of the studied PCBs. The two PCBs that were highly embryo toxic were observed to be estrogenic.

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

    PubMed Central

    Bluhm, Kerstin; Otte, Jens C.; Yang, Lixin; Zinsmeister, Christian; Legradi, Jessica; Keiter, Steffen; Kosmehl, Thomas; Braunbeck, Thomas; Strähle, Uwe; Hollert, Henner

    2014-01-01

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

  17. Inhibitory avoidance learning in zebrafish (Danio rerio): effects of shock intensity and unraveling differences in task performance.

    PubMed

    Manuel, Remy; Gorissen, Marnix; Roca, Carme Piza; Zethof, Jan; van de Vis, Hans; Flik, Gert; van den Bos, Ruud

    2014-08-01

    The zebrafish (Danio rerio) is increasingly used as a model in neurobehavioral and neuroendocrine studies. The inhibitory avoidance paradigm has been proposed as tool to study mechanisms underlying learning and memory in zebrafish. In this paradigm subjects receive a shock after entering the black compartment of a black-white box. On the next day, latency to enter the black compartment is assessed; higher latencies are indicative of increased avoidance learning. Here, we aimed to understand the effects of different shock intensities (0, 1, 3, and 9 V) and to unravel variation in inhibitory avoidance learning in an in-house reared Tuebingen Long-Fin zebrafish (D. rerio) strain. While median latencies had increased in the 1, 3, and 9 V groups, no increase in median latency was found in the 0 V group. In addition, higher shock intensities resulted in a higher number of avoiders (latency ≥180 s) over nonavoiders (latency <60 s). Both changes are indicative of increased avoidance learning. We assessed whole-body cortisol content and the expression levels of genes relevant to stress, anxiety, fear, and learning 2 h after testing. Shock intensity was associated with whole-body cortisol content and the expression of glucocorticoid receptor alpha [nr3c1(alpha)], cocaine- and amphetamine-regulated transcript (cart4), and mineralocorticoid receptor (nr3c2), while avoidance behavior was associated with whole-body cortisol content only. The inhibitory avoidance paradigm in combination with measuring whole-body cortisol content and gene expression is suitable to unravel (genetic) mechanisms of fear avoidance learning. Our data further show differences in brain-behavior relationships underlying fear avoidance learning and memory in zebrafish. These findings serve as starting point for further unraveling differences in brain-behavior relationships underlying (fear avoidance) learning and memory in zebrafish.

  18. Inhibitory Avoidance Learning in Zebrafish (Danio Rerio): Effects of Shock Intensity and Unraveling Differences in Task Performance

    PubMed Central

    Gorissen, Marnix; Piza Roca, Carme; Zethof, Jan; van de Vis, Hans; Flik, Gert; van den Bos, Ruud

    2014-01-01

    Abstract The zebrafish (Danio rerio) is increasingly used as a model in neurobehavioral and neuroendocrine studies. The inhibitory avoidance paradigm has been proposed as tool to study mechanisms underlying learning and memory in zebrafish. In this paradigm subjects receive a shock after entering the black compartment of a black-white box. On the next day, latency to enter the black compartment is assessed; higher latencies are indicative of increased avoidance learning. Here, we aimed to understand the effects of different shock intensities (0, 1, 3, and 9 V) and to unravel variation in inhibitory avoidance learning in an in-house reared Tuebingen Long-Fin zebrafish (D. rerio) strain. While median latencies had increased in the 1, 3, and 9 V groups, no increase in median latency was found in the 0 V group. In addition, higher shock intensities resulted in a higher number of avoiders (latency ≥180 s) over nonavoiders (latency <60 s). Both changes are indicative of increased avoidance learning. We assessed whole-body cortisol content and the expression levels of genes relevant to stress, anxiety, fear, and learning 2 h after testing. Shock intensity was associated with whole-body cortisol content and the expression of glucocorticoid receptor alpha [nr3c1(alpha)], cocaine- and amphetamine-regulated transcript (cart4), and mineralocorticoid receptor (nr3c2), while avoidance behavior was associated with whole-body cortisol content only. The inhibitory avoidance paradigm in combination with measuring whole-body cortisol content and gene expression is suitable to unravel (genetic) mechanisms of fear avoidance learning. Our data further show differences in brain-behavior relationships underlying fear avoidance learning and memory in zebrafish. These findings serve as starting point for further unraveling differences in brain-behavior relationships underlying (fear avoidance) learning and memory in zebrafish. PMID:25004302

  19. Dietary selenomethionine influences the accumulation and depuration of dietary methylmercury in zebrafish (Danio rerio).

    PubMed

    Amlund, Heidi; Lundebye, Anne-Katrine; Boyle, David; Ellingsen, Ståle

    2015-01-01

    Methylmercury (MeHg) is a toxicant of concern for aquatic food chains. In the present study, the assimilation and depuration of dietary MeHg and the influence of dietary selenium on MeHg toxicokinetics was characterised in zebrafish (Danio rerio). In a triplicate tank experimental design (n=3 tanks per treatment group), adult zebrafish were exposed to dietary MeHg (as methylmercury-cysteine) at 5 and 10 μg/g and with or without selenium (as selenomethionine) supplemented to the diets at a concentration of 5 μg/g for 8 weeks followed by a 4-week depuration period. Methylmercury accumulated in muscle, liver and brain of zebrafish; with higher mercury concentrations in liver and brain than in muscle following 8 weeks of exposure. In muscle, the mercury concentrations were 3.4±0.2 and 6.4±0.1 μg/g ww (n=3) in zebrafish fed the 5 and 10 μg Hg/g diets, respectively. During the depuration period, mercury concentrations were significantly reduced in muscle in both the 5 and 10 μg Hg/g diet groups with a greater reduction in the high dose group. After depuration, the mercury concentrations were 2.4±0.1 and 4.0±0.3 μg/g ww (n=3) for zebrafish fed the 5 and 10 μg Hg/g diets, respectively. Data also indicated that supplemented dietary selenium reduced accumulation of MeHg and enhanced the elimination of MeHg. Lower levels of mercury were found in muscle of zebrafish fed MeHg and SeMet compared with fish fed only MeHg after 8 weeks exposure; the mercury concentrations in muscle were 5.8±0.2 and 6.4±0.1 μg/g ww (n=3) for zebrafish fed the 10 μg Hg/g+5 μg Se/g diet and the 10 μg Hg/g diet, respectively. Furthermore, the elimination of MeHg from muscle during the 4-week depuration period was significantly greater in the fish fed the diet containing SeMet compared to a control diet; the mercury concentrations were 3.3±0.1 and 4.0±0.3 μg/g ww (n=3) for zebrafish fed the 5 μg Se/g and the control diets, respectively. In summary, dietary SeMet reduces the

  20. Genome-wide identification of suitable zebrafish Danio rerio reference genes for normalization of gene expression data by RT-qPCR.

    PubMed

    Xu, H; Li, C; Zeng, Q; Agrawal, I; Zhu, X; Gong, Z

    2016-06-01

    In this study, to systematically identify the most stably expressed genes for internal reference in zebrafish Danio rerio investigations, 37 D. rerio transcriptomic datasets (both RNA sequencing and microarray data) were collected from gene expression omnibus (GEO) database and unpublished data, and gene expression variations were analysed under three experimental conditions: tissue types, developmental stages and chemical treatments. Forty-four putative candidate genes were identified with the c.v. <0·2 from all datasets. Following clustering into different functional groups, 21 genes, in addition to four conventional housekeeping genes (eef1a1l1, b2m, hrpt1l and actb1), were selected from different functional groups for further quantitative real-time (qrt-)PCR validation using 25 RNA samples from different adult tissues, developmental stages and chemical treatments. The qrt-PCR data were then analysed using the statistical algorithm refFinder for gene expression stability. Several new candidate genes showed better expression stability than the conventional housekeeping genes in all three categories. It was found that sep15 and metap1 were the top two stable genes for tissue types, ube2a and tmem50a the top two for different developmental stages, and rpl13a and rp1p0 the top two for chemical treatments. Thus, based on the extensive transcriptomic analyses and qrt-PCR validation, these new reference genes are recommended for normalization of D. rerio qrt-PCR data respectively for the three different experimental conditions.

  1. [Joint locus of a/b-globin genes in Danio rerio is segregated into structural subdomains active at different stages of development].

    PubMed

    Dolgushin, K V; Petrova, N V; Iudinkova, E S; Razin, S V; Iarovaia, O V

    2015-01-01

    In the domain model of eukaryotic genome organization, the functional unit of the genome, along with the relevant regulatory elements, is considered to be a gene or a gene family. In hot-blooded vertebrate animals, the domains of a- and b-globin genes are positioned at different chromosomes and are organized and regulated in different fashion. In cold-blooded animals, in particular in tropical fish Danio rerio, a- and b globin genes are located in a common gene cluster. However, the joint a/b-globin gene cluster is subdivided into two development stage-specific subdomains, the adult one and the embryonic-larval one. In an attempt to find out whether this functional segregation correlates with structural segregation of the domain we compared the DNase I sensitivity and profiles of histone modifications of adult and embryonic-larval segments of the domain in cultured D. rerio fibroblasts. We have demonstrated that, in these nonerythroid cells, adult and embryonic- larval subdomains possess different DNase I sensitivities and different profiles of H3K27me3, a histone modification introduced by PRC2 complex. These observations suggest that joint a/b globin gene domain of Danio rerio is segregated into two structural subdomain harboring adult and embryonic-larval globin genes. PMID:26107904

  2. Decision Processes During Development of Molecular Biomarkers for Gonadal Phenotypic Sex

    EPA Science Inventory

    Molecular biomarkers for determination of gonadal phenotypic sex in the Japanese medaka (Oryzias latipes), will serve as a case study. The medaka has unique features that aid in the development of appropriate molecular biomarkers of gonad phenotype, a) genetic sex can be determin...

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

    ERIC Educational Resources Information Center

    Tang, Sherry

    2012-01-01

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

  4. Synthesis and biological evaluation of alkoxycoumarins as novel nematicidal constituents.

    PubMed

    Takaishi, Kazuto; Izumi, Minoru; Baba, Naomichi; Kawazu, Kazuyoshi; Nakajima, Shuhei

    2008-10-15

    We synthesized all of the monomethoxycoumarins, 5-alkoxycoumarins and their derivatives, and investigated their nematicidal activity against the phytopathogenic nematode, Bursaphelenchus xylophilus. Among the compounds, 5-ethoxycoumarin showed the highest nematicidal activity. Furthermore, 5-ethoxycoumarin was comparatively harmless against both the brine shrimps, Artemia salina, and the Japanese killifish, Oryzias latipes. PMID:18793855

  5. Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking.

    PubMed

    Makarova, Katerina; Siudem, Pawel; Zawada, Katarzyna; Kurkowiak, Justyna

    2016-10-01

    Bisphenol A (BPA) acts as an endocrine-disrupting compound even at a low concentration. Degradation of BPA could lead to the formation of toxic products. In this study, we compare the toxicity of BPA and seven intermediate products of its degradation. The accuracy of three molecular docking programs (Surflex, Autodock, and Autodock Vina) in predicting the binding affinities of selected compounds to human (ERα, ERβ, and ERRγ) and zebrafish (ERα, ERRγA, and ERRγB) estrogen and estrogen-related receptors was evaluated. The docking experiments showed that 4-isopropylphenol could have similar toxicity to that of BPA due to its high affinity to ERRγ and ERRγB and high octanol-water partitioning coefficient. The least toxic compounds were hydroquinone and phenol. Those compounds as well as BPA were screened in the zebrafish (Danio rerio) embryo test. 4-isopropylphenol had the strongest toxic effect on zebrafish embryos and caused 100% lethality shortly after exposure. BPA caused the delay in development, multiple deformations, and low heartbeats (30 bps), whereas hydroquinone had no impact on the development of the zebrafish embryo. Thus, the results of zebrafish screening are in good agreement with our docking experiment. The molecular docking could be used to screen the toxicity of other xenoestrogens and their products of degradation. PMID:27486708

  6. Growth hormone (GH) increases cognition and expression of ionotropic glutamate receptors (AMPA and NMDA) in transgenic zebrafish (Danio rerio).

    PubMed

    Studzinski, Ana Lupe Motta; Barros, Daniela Martí; Marins, Luis Fernando

    2015-11-01

    The growth hormone/insulin-like factor I (GH/IGF-I) somatotropic axis is responsible for somatic growth in vertebrates, and has important functions in the nervous system. Among these, learning and memory functions related to the neural expression of ionotropic glutamate receptors, mainly types AMPA (α-amino-3hydroxy-5methylisoxazole-4propionic) and NMDA (N-methyl-d-aspartate) can be highlighted. Studies on these mechanisms have been almost exclusively conducted on mammal models, with little information available on fish. Consequently, this study aimed at evaluating the effects of the somatotropic axis on learning and memory of a GH-transgenic zebrafish (Danio rerio) model (F0104 strain). Long-term memory (LTM) was tested in an inhibitory avoidance apparatus, and brain expression of igf-I and genes that code for the main subunits of the AMPA and NMDA receptors were evaluated. Results showed a significant increase in LTM for transgenic fish. Transgenic animals also showed a generalized pattern of increase in the expression of AMPA and NMDA genes, as well as a three-fold induction in igf-I expression in the brain. When analyzed together, these results indicate that GH, mediated by IGF-I, has important effects on the brain, with improvement in LTM as a result of increased glutamate receptors. The transgenic strain F0104 was shown to be an interesting model for elucidating the intricate mechanisms related to the effect of the somatotropic axis on learning and memory in vertebrates.

  7. Toxicity of cylindrospermopsin, and other apparent metabolites from Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum, to the zebrafish (Danio rerio) embryo

    PubMed Central

    Berry, John P.; Gibbs, Patrick D.L.; Schmale, Michael C.; Saker, Martin L.

    2012-01-01

    Cyanobacteria produce a diverse array of toxic or otherwise bioactive compounds that pose growing threats to human and environmental health. We utilized the zebrafish (Danio rerio) embryo, as a model of vertebrate development, to investigate the inhibition of development pathways (i.e. developmental toxicity) by the cyanobacterial toxin, cylindrospermopsin (CYN), as well as extracts from various isolates of Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum. CYN was toxic only when injected directly into embryos, but not by direct immersion at doses up to 50 μg/ml. Despite the dose dependency of toxicity observed following injection of CYN, no consistent patterns of developmental defects were observed, suggesting that toxic effects of CYN may not target specific developmental pathways. In contrast, direct immersion of embryos in all of the extracts resulted in both increased mortality and reproducible, consistent, developmental dysfunctions. Interestingly, there was no correlation of developmental toxicity observed for these extracts with the presence of CYN or with previously reported toxicity for these strains. These results suggest that CYN is lethal to zebrafish embryos, but apparently inhibits no specific developmental pathways, whereas other apparent metabolites from C. raciborskii and A. ovalisporum seem to reproducibly inhibit development in the zebrafish model. Continued investigation of these apparent, unknown metabolites is needed. PMID:19087885

  8. Lagos lagoon sediment organic extracts and polycyclic aromatic hydrocarbons induce embryotoxic, teratogenic and genotoxic effects in Danio rerio (zebrafish) embryos.

    PubMed

    Sogbanmu, Temitope O; Nagy, Eszter; Phillips, David H; Arlt, Volker M; Otitoloju, Adebayo A; Bury, Nic R

    2016-07-01

    An expansion of anthropogenic activity around Lagos lagoon, Nigeria, has raised concerns over increasing contaminants entering the lagoon's ecosystem. The embryotoxicity, teratogenicity and genotoxicity of sediment organic extracts from four sampling zones around Lagos lagoon, Ilaje, Iddo, Atlas Cove and Apapa, as well as the dominant polycyclic aromatic hydrocarbons (PAHs) identified in water measured during the wet season (naphthalene, phenanthrene, pyrene, benzo[a]pyrene and a mixture of these), were assessed with Danio rerio embryos. Embryos were exposed to varying concentrations of toxicants from 0-72 h post-fertilization (hpf). Embryotoxicity at 72 hpf showed a dose-dependent increase in mortality upon exposure to extracts from all zones, except Atlas Cove. Similarly, higher levels of teratogenic effects, such as increased oedema, and haemorrhage and developmental abnormalities resulted from exposure to extracts from Ilaje, Iddo and Apapa zones. Treatment with single PAHs revealed that significant levels of detrimental effects were obtained only for phenanthrene. The modified comet assay revealed that the oxidative damage to DNA was generally low (<12 %) overall for all sediment extracts, but was significantly elevated with Ilaje and Iddo sediment extracts when compared with solvent controls. Oxidative damage was observed with the single PAHs, phenanthrene and benzo[a]pyrene, as well as with the PAH mixture. This study highlights that Lagos lagoon sediment extracts have teratogenic, embryotoxic and genotoxic properties, which are likely due to the high molecular weight PAHs present in the extracts, some of which are known or are suspected human carcinogens. PMID:27068906

  9. Growth hormone (GH) increases cognition and expression of ionotropic glutamate receptors (AMPA and NMDA) in transgenic zebrafish (Danio rerio).

    PubMed

    Studzinski, Ana Lupe Motta; Barros, Daniela Martí; Marins, Luis Fernando

    2015-11-01

    The growth hormone/insulin-like factor I (GH/IGF-I) somatotropic axis is responsible for somatic growth in vertebrates, and has important functions in the nervous system. Among these, learning and memory functions related to the neural expression of ionotropic glutamate receptors, mainly types AMPA (α-amino-3hydroxy-5methylisoxazole-4propionic) and NMDA (N-methyl-d-aspartate) can be highlighted. Studies on these mechanisms have been almost exclusively conducted on mammal models, with little information available on fish. Consequently, this study aimed at evaluating the effects of the somatotropic axis on learning and memory of a GH-transgenic zebrafish (Danio rerio) model (F0104 strain). Long-term memory (LTM) was tested in an inhibitory avoidance apparatus, and brain expression of igf-I and genes that code for the main subunits of the AMPA and NMDA receptors were evaluated. Results showed a significant increase in LTM for transgenic fish. Transgenic animals also showed a generalized pattern of increase in the expression of AMPA and NMDA genes, as well as a three-fold induction in igf-I expression in the brain. When analyzed together, these results indicate that GH, mediated by IGF-I, has important effects on the brain, with improvement in LTM as a result of increased glutamate receptors. The transgenic strain F0104 was shown to be an interesting model for elucidating the intricate mechanisms related to the effect of the somatotropic axis on learning and memory in vertebrates. PMID:26235327

  10. Reprint of "Pharmacological study of the light/dark preference test in zebrafish (Danio rerio): Waterborne administration".

    PubMed

    Magno, Lílian Danielle Paiva; Fontes, Aldo; Gonçalves, Beatriz Maria Necy; Gouveia, Amauri

    2015-12-01

    Anxiety is a complex disorder; thus, its mechanisms remain unclear. Zebrafish (Danio rerio) are a promising pharmacological model for anxiety research. Light/dark preference test is a behaviorally validated measure of anxiety in zebrafish; however, it requires pharmacological validation. We sought to evaluate the sensitivity of the light/dark preference test in adult zebrafish by immersing them in drug solutions containing clonazepam, buspirone, imipramine, fluoxetine, paroxetine, haloperidol, risperidone, propranolol, or ethanol. The time spent in the dark environment, the latency time to first crossing, and the number of midline crossings were analyzed. Intermediate concentrations of clonazepam administered for 600s decreased the time spent in the dark and increased locomotor activity. Buspirone reduced motor activity. Imipramine and fluoxetine increased time spent in the dark and the first latency, and decreased the number of alternations. Paroxetine did not alter the time in the dark; however, it increased the first latency time and decreased locomotor activity. Haloperidol decreased the time spent in the dark at low concentrations. Risperidone and propranolol did not change any parameters. Ethanol reduced the time spent in the dark and increased the number of crossings at intermediate concentrations. These results corroborate the previous work using intraperitoneal drug administration in zebrafish and rodents, suggesting that water drug delivery in zebrafish can effectively be used as an animal anxiety model.

  11. Toxicity of urban highway runoff in Shanghai to Zebrafish (Danio rerio ) embryos and luminous bacteria (Vibrio qinghaiensis.Q67).

    PubMed

    Wu, Lingling; Jiang, Yue; Zhang, Lili; Chen, Ling; Zhang, Haiping

    2014-02-01

    Pollution from urban highway runoff has been identified as one of the major causes of the deterioration of receiving water quality. The purpose of this study is to assess the toxicity of urban storm water samples in Shanghai using the zebrafish (Danio rerio ) embryo test and the bacterial luminescence (Vibrio qinghaiensis ) assay. The toxicity of highway runoff from seventeen storm events was investigated in both grab and composite samples. Zebrafish embryos were exposed to the runoff samples and development parameters including lethality, spontaneous movements in 20 s, heart beat rate, hatching rate, and abnormality of zebrafish embryos were observed after 24, 48, 72, and 96 h of exposure. Inhibition rates of luminescence intensity were also recorded. The results showed that in the zebrafish embryo toxicity tests, both grab and composite samples increased the lethality, reduced the percentage with spontaneous movements and heart beats, inhibited the hatching of embryos, and induced morphological abnormalities. In the Vibrio qinghaiensis toxicity test, all the grab samples inhibited the luminescence, while some of the composite samples promoted it, which indicated that different types of toxicants might have been affecting the species. The multivariate statistics analysis indicated that heavy metal (zinc, manganese, and copper) and PAHs might mainly contribute to the toxicity of runoff samples.

  12. Effects of dietary biotin and avidin on growth, survival, feed conversion, biotin status and gene expression of zebrafish Danio rerio.

    PubMed

    Yossa, Rodrigue; Sarker, Pallab K; Karanth, Santhosh; Ekker, Marc; Vandenberg, Grant W

    2011-12-01

    A study was conducted to investigate the effects of dietary avidin on growth, survival, food conversion, biotin status and gene expression of zebrafish (Danio rerio Hamilton-Buchanan) juveniles (average wet mass 0.178 g) fed 7 purified diets for 12 weeks. Experimental diets were formulated to provide 0×, 1×, 15×, 30×, 60× and 120× excess avidin versus biotin kg(-1) diet, on a molar basis; a control diet contained neither supplemental biotin nor avidin. Fish fed the control diet had the lowest percentage weight gain and the highest mortality, while the highest percentage weight gain and the lowest mortality was observed with the 0× diet (P<0.05). A linear relationship was observed between feed conversion ratio (FCR) and dietary avidin (r=0.876; P<0.0001). Fish fed diets with 120× more avidin than biotin had the highest whole-body biotin content, while the lowest value was obtained with the control and avidin-free diets (P<0.05). Elevated levels of acetyl CoA carboxylase-A (acca), methylcrotonyl CoA carboxylase (mcc) and propionyl CoA carboxylase-A (pcca) transcripts were recorded in fish fed the control diet, in comparison to the other diets. A broken-line analysis indicated that feeding zebrafish a diet with 60 times more avidin than the dietary biotin requirement level will cause biotin deficiency signs.

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

    PubMed Central

    Kist, Luiza Wilges; Piato, Angelo Luis; da Rosa, João Gabriel Santos; Koakoski, Gessi; Barcellos, Leonardo José Gil; Yunes, João Sarkis; Bonan, Carla Denise; Bogo, Maurício Reis

    2011-01-01

    Microcystins (MCs) are toxins produced by cyanobacteria (blue-green algae), primarily Microcystis aeruginosa, forming water blooms worldwide. When an organism is exposed to environmental perturbations, alterations in normal behavioral patterns occur. Behavioral repertoire represents the consequence of a diversity of physiological and biochemical alterations. In this study, we assessed behavioral patterns and whole-body cortisol levels of adult zebrafish (Danio rerio) exposed to cell culture of the microcystin-producing cyanobacterium M. aeruginosa (MC-LR, strain RST9501). MC-LR exposure (100 μg/L) decreased by 63% the distance traveled and increased threefold the immobility time when compared to the control group. Interestingly, no significant alterations in the number of line crossings were found at the same MC-LR concentration and time of exposure. When animals were exposed to 50 and 100 μg/L, MC-LR promoted a significant increase (around 93%) in the time spent in the bottom portion of the tank, suggesting an anxiogenic effect. The results also showed that none of the MC-LR concentrations tested promoted significant alterations in absolute turn angle, path efficiency, social behavior, or whole-body cortisol level. These findings indicate that behavior is susceptible to MC-LR exposure and provide evidence for a better understanding of the ecological consequences of toxic algal blooms. PMID:22253623

  14. Effects of Tributyltin and Other Retinoid Receptor Agonists in Reproductive-Related Endpoints in the Zebrafish (Danio rerio).

    PubMed

    Lima, Daniela; Castro, L Filipe C; Coelho, Inês; Lacerda, Ricardo; Gesto, Manuel; Soares, Joana; André, Ana; Capela, Ricardo; Torres, Tiago; Carvalho, António Paulo; Santos, Miguel M

    2015-01-01

    Both field and experimental data examined the influence of exposure to environmental contaminant tributyltin (TBT) on marine organisms. Although most attention focused on the imposex phenomenon in gastropods, adverse effects were also observed in other taxonomic groups. It has been shown that imposex induction involves modulation of retinoid signaling in gastropods. Whether TBT influences similar pathways in fish is yet to be addressed. In this study, larvae of the model teleost Danio rerio were exposed to natural retinoids, all-trans-retinoic acid, 9-cis-retinoic acid, and all-trans-retinol, as well as to the RXR synthetic pan-agonist methoprene acid (MA) and to TBT. Larvae were exposed to TBT from 5 days post fertilization (dpf) to adulthood, and reproductive capacity was assessed and correlated with mode of action. TBT significantly decreased fecundity at environmentally relevant levels at 1 μg TBT Sn/g in diet. Interestingly, in contrast to previous reports, TBT altered zebrafish sex ratio toward females, whereas MA exposure biased sex toward males. Since fecundity was significantly altered in the TBT-exposed group with up to 62% decrease, the potentially affected pathways were investigated. Significant downregulation was observed in brain mRNA levels of aromatase b (CYP19a1b) in females and peroxisome proliferator activated receptor gamma (PPARg) in both males and females, suggesting an involvement of these pathways in reproductive impairment associated with TBT. PMID:26090559

  15. Effects of simulated microgravity on the development of the swimbladder and buoyancy control in larval zebrafish (Danio rerio).

    PubMed

    Lindsey, Benjamin W; Dumbarton, Tristan C; Moorman, Stephen J; Smith, Frank M; Croll, Roger P

    2011-06-01

    The gas-filled swimbladder of teleost fishes provides hydrodynamic lift which counteracts the high density of other body tissues, and thereby allows the fish to achieve neutral buoyancy with minimal energy expenditure. In this study, we examined whether the absence of a constant direction gravitational vector affects the ontogeny of the swimbladder and buoyancy control in zebrafish (Danio rerio). We exposed fertilized eggs to simulated microgravity (SMG) in a closed rotating wall vessel with control eggs placed in a similar but nonrotating container. All eggs hatched in both groups. At 96 hr of postfertilization (hpf), all larvae were removed from the experimental and control vessels. At this point, 62% of the control larvae, but only 14% of SMG-exposed larvae, were observed to have inflated their swimbladder. In addition, the mean volume of the inflated swimbladders was significantly greater in the control larvae compared with larvae raised in SMG. After transfer to open stationary observation tanks, larvae with uninflated swimbladders in both groups swam to the surface to complete inflation, but this process was significantly delayed in larvae exposed to SMG. Initial differences in swimbladder inflation and volume between groups disappeared by 144 hpf. Furthermore, there were no apparent changes in patterns of development and maturation of swimbladder musculature, vasculature, or innervation resulting from SMG exposure at later stages of ontogeny. These data indicate that, despite a transient delay in swimbladder inflation in zebrafish larvae exposed to SMG, subsequent swimbladder development in these animals proceeded similarly to that in normal larvae. PMID:21394929

  16. Developmental toxicity and endocrine disruption of naphthenic acids on the early life stage of zebrafish (Danio rerio).

    PubMed

    Wang, Jie; Cao, Xiaofeng; Huang, Yi; Tang, Xiaoyan

    2015-12-01

    Oil sands process-affected water (OSPW) has been reported to exhibit adverse effects on the environment and wildlife. Although the compounds responsible are unknown, naphthenic acids (NAs) have been considered to be implicated. The current study was designed to investigate whether NAs might cause developmental toxicity and endocrine disruption on the early life stage of zebrafish (Danio rerio). The success of embryo hatch was inhibited by 2.5 mg l(-1) oil sands NAs (OS-NAs) exposure, and both OSPW NAs and commercial NAs (C-NAs) exposure resulted in a variety of developmental lesions in the fish larvae, such as yolk sac edema, pericardial edema and spinal malformation. The transcription of genes involved cytochrome P450 aromatase (CYP19a and CYP19b), estrogen receptors (ERα, ERβ1 and ERβ2), and vitellogenin (VTG) was analyzed to evaluate the endocrine disrupting effects of NAs. Significant up-regulated gene expressions of CYP19b, ERα and VTG were observed in both OS-NAs and C-NAs groups, which indicated the deleteriously estrogenic potential of NAs. These results confirmed that NAs derived from crude petroleum could negatively impact the development and endocrine function of zebrafish, and be primarily responsible for the toxicity of OSPW.

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

    PubMed Central

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

    2016-01-01

    Abstract Background An attractive approach in the study of human cancers is the use of transparent zebrafish (Danio rerio) embryos, which enable the visualization of cancer progression in a living animal. Materials and methods We implanted mixtures of fluorescently labeled glioblastoma (GBM) cells and bonemarrow-derived mesenchymal stem cells (MSCs) into zebrafish embryos to study the cellular pathways of their invasion and the interactions between these cells in vivo. Results By developing and applying a carbocyanine-dye-compatible clearing protocol for observation of cells in deep tissues, we showed that U87 and U373 GBM cells rapidly aggregated into tumor masses in the ventricles and midbrain hemispheres of the zebrafish embryo brain, and invaded the central nervous system, often using the ventricular system and the central canal of the spinal cord. However, the GBM cells did not leave the central nervous system. With co-injection of differentially labeled cultured GBM cells and MSCs, the implanted cells formed mixed tumor masses in the brain. We observed tight associations between GBM cells and MSCs, and possible cell-fusion events. GBM cells and MSCs used similar invasion routes in the central nervous system. Conclusions This simple model can be used to study the molecular pathways of cellular processes in GBM cell invasion, and their interactions with various types of stromal cells in double or triple cell co-cultures, to design anti-GBM cell therapies that use MSCs as vectors. PMID:27247548

  18. Back to basics: searching for a comprehensive framework for exploring individual differences in zebrafish (Danio rerio) behavior.

    PubMed

    Toms, Christina N; Echevarria, David J

    2014-08-01

    Individual differences (IDs) in behavior among nonhuman animals have been documented in a wide range of taxa. Although traditionally considered noise around an average, other potentially adaptive sources of phenotypic variation exist. IDs in behavior that are consistent across time and context are more recently recognized as expressions of underlying personality traits, which may even be heritable. Unfortunately, despite the rapid advances that have been made in animal personality research utilizing fish the last decade, a few have detailed the groundwork necessary to document consistency in behavior across time and context. This foundation is required, by definition, before one can draw conclusions about personality traits. Here, we examine whether IDs in behavior are consistent over time and across contexts and explore the construct validity of six commonly used behavioral assays for examining four personality traits: aggression, boldness, fear, and exploration. Thirty zebrafish (Danio rerio) were exposed twice each to a small open field, large open field, mirror, emergence, novel object, and predator response test. Results revealed consistency in most behavioral measures across both time and context. There was mixed evidence for the construct validity of these assays in capturing the targeted personality traits. PMID:24921670

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

    PubMed Central

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

    2016-01-01

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

  20. The first characterization of multidrug and toxin extrusion (MATE/SLC47) proteins in zebrafish (Danio rerio)

    PubMed Central

    Lončar, Jovica; Popović, Marta; Krznar, Petra; Zaja, Roko; Smital, Tvrtko

    2016-01-01

    Multidrug and toxin extrusion (MATE) proteins are involved in the extrusion of endogenous compounds and xenobiotics across the plasma membrane. They are conserved from bacteria to mammals, with different numbers of genes within groups. Here, we present the first data on identification and functional characterization of Mate proteins in zebrafish (Danio rerio). Phylogenetic analysis revealed six Mates in teleost fish, annotated as Mate3–8, which form a distinct cluster separated from the tetrapod MATEs/Mates. Synteny analysis showed that zebrafish mate genes are orthologous to human MATEs. Gene expression analysis revealed that all the mate transcripts were constitutively and differentially expressed during embryonic development, followed by pronounced and tissue-specific expression in adults. Functional analyses were performed using transport activity assays with model substrates after heterologous overexpression of five zebrafish Mates in HEK293T cells. The results showed that zebrafish Mates interact with both physiological and xenobiotic substances but also substantially differ with respect to the interacting compounds and interaction strength in comparison to mammalian MATEs/Mates. Taken together, our data clearly indicate a potentially important role for zebrafish Mate transporters in zebrafish embryos and adults and provide a basis for detailed functional characterizations of single zebrafish Mate transporters. PMID:27357367

  1. Thyroid disruption in zebrafish (Danio rerio) larvae: Different molecular response patterns lead to impaired eye development and visual functions.

    PubMed

    Baumann, Lisa; Ros, Albert; Rehberger, Kristina; Neuhauss, Stephan C F; Segner, Helmut

    2016-03-01

    The vertebrate thyroid system is important for multiple developmental processes, including eye development. Thus, its environmentally induced disruption may impact important fitness-related parameters like visual capacities and behaviour. The present study investigated the relation between molecular effects of thyroid disruption and morphological and physiological changes of eye development in zebrafish (Danio rerio). Two test compounds representing different molecular modes of thyroid disruption were used: propylthiouracil (PTU), which is an enzyme-inhibitor of thyroid hormone synthesis, and tetrabromobisphenol A (TBBPA), which interacts with the thyroid hormone receptors. Both chemicals significantly altered transcript levels of thyroid system-related genes (TRα, TRβ, TPO, TSH, DIO1, DIO2 and DIO3) in a compound-specific way. Despite these different molecular response patterns, both treatments resulted in similar pathological alterations of the eyes such as reduced size, RPE cell diameter and pigmentation, which were concentration-dependent. The morphological changes translated into impaired visual performance of the larvae: the optokinetic response was significantly and concentration-dependently decreased in both treatments, together with a significant increase of light preference of PTU-treated larvae. In addition, swimming activity was impacted. This study provides first evidence that different modes of molecular action of the thyroid disruptors can be associated with uniform apical responses. Furthermore, this study is the first to show that pathological eye development, as it can be induced by exposure to thyroid disruptors, indeed translates into impaired visual capacities of zebrafish early life stages.

  2. Bioconcentration of (15)N-tamoxifen at environmental concentration in liver, gonad and muscle of Danio rerio.

    PubMed

    Orias, Frédéric; Simon, Laurent; Mialdea, Gladys; Clair, Angéline; Brosselin, Vanessa; Perrodin, Yves

    2015-10-01

    Pharmaceutical compounds (PCs) are ubiquitous in aquatic ecosystems. In addition to the direct ecotoxicological risk presented by certain PCs, others can accumulate inside organisms and along trophic webs, subsequently contaminating whole ecosystems. We studied the bioconcentration of a bioaccumulative PC already found several times in the environment: tamoxifen. To this end, we exposed Danio rerio for 21d to (15)N-tamoxifen concentrations ranging from 0.1 to 10µg/L and used an analytic method based on stable isotopes to evaluate the tamoxifen content in these organisms. The evolution of the (15)N/(14)N ratio was thus measured in liver, muscle and gonads of exposed fish compared to control fish. We succeeded in quantifying (15)N-tamoxifen bioconcentrations at all the exposure concentrations tested. The highest bioconcentration factors of tamoxifen measured were 14,920 in muscle, 73,800 in liver and 85,600 in gonads of fish after 21d exposure at a nominal concentration of 10µg/L. However, these bioconcentration factors have to be considered as maximal values (BCFMAX). Indeed, despite its proven stability, tamoxifen can be potentially partially degraded during experiments. We now need to refine these results by using a direct analytic method (i.e. LC-MS/MS). PMID:26163873

  3. Exosome Delivered Anticancer Drugs Across the Blood-Brain Barrier for Brain Cancer Therapy in Danio Rerio

    PubMed Central

    Yang, Tianzhi; Martin, Paige; Fogarty, Brittany; Brown, Alison; Schurman, Kayla; Phipps, Roger; Yin, Viravuth P.; Lockman, Paul

    2015-01-01

    Purpose The blood–brain barrier (BBB) essentially restricts therapeutic drugs from entering into the brain. This study tests the hypothesis that brain endothelial cell derived exosomes can deliver anticancer drug across the BBB for the treatment of brain cancer in a zebrafish (Danio rerio) model. Materials and Methods Four types of exosomes were isolated from brain cell culture media and characterized by particle size, morphology, total protein, and transmembrane protein markers. Transport mechanism, cell uptake, and cytotoxicity of optimized exosome delivery system were tested. Brain distribution of exosome delivered anticancer drugs was evaluated using transgenic zebrafish TG (fli1: GFP) embryos and efficacies of optimized formations were examined in a xenotransplanted zebrafish model of brain cancer model. Results Four exosomes in 30–100 diameters showed different morphologies and exosomes derived from brain endothelial cells expressed more CD63 tetraspanins transmembrane proteins. Optimized exosomes increased the uptake of fluorescent marker via receptor mediated endocytosis and cytotoxicity of anticancer drugs in cancer cells. Images of the zebrafish showed exosome delivered anticancer drugs crossed the BBB and entered into the brain. In the brain cancer model, exosome delivered anticancer drugs significantly decreased fluorescent intensity of xenotransplanted cancer cells and tumor growth marker. Conclusions Brain endothelial cell derived exosomes could be potentially used as a carrier for brain delivery of anticancer drug for the treatment of brain cancer. PMID:25609010

  4. Effects of the Dietary ω3:ω6 Fatty Acid Ratio on Body Fat and Inflammation in Zebrafish (Danio rerio)

    PubMed Central

    Powell, Mickie L; Pegues, Melissa A; Szalai, Alexander J; Ghanta, Vithal K; D'Abramo, Louis R; Watts, Stephen A

    2015-01-01

    The diets of populations in industrialized nations have shifted to dramatically increased consumption of ω6 polyunsaturated fatty acids (PUFA), with a corresponding decrease in the consumption of ω3 PUFA. This dietary shift may be related to observed increases in obesity, chronic inflammation, and comorbidities in the human population. We examined the effects of ω3:ω6 fatty acid ratios in the context of constant total dietary lipid on the growth, total body fat, and responses of key inflammatory markers in adult zebrafish (Danio rerio). Zebrafish were fed diets in which the ω3:ω6 PUFA ratios were representative of those in a purported ancestral diet (1:2) and more contemporary Western diets (1:5 and 1:8). After 5 mo, weight gain (fat free mass) of zebrafish was highest for those that received the 1:8 ratio treatment, but total body fat was lowest at this ratio. Measured by quantitative real-time RT–PCR, mRNA levels from liver samples of 3 chronic inflammatory response genes (C-reactive protein, serum amyloid A, and vitellogenin) were lowest at the 1:8 ratio. These data provide evidence of the ability to alter zebrafish growth and body composition through the quality of dietary lipid and support the application of this model to investigations of human health and disease related to fat metabolism. PMID:26310458

  5. The first characterization of multidrug and toxin extrusion (MATE/SLC47) proteins in zebrafish (Danio rerio).

    PubMed

    Lončar, Jovica; Popović, Marta; Krznar, Petra; Zaja, Roko; Smital, Tvrtko

    2016-01-01

    Multidrug and toxin extrusion (MATE) proteins are involved in the extrusion of endogenous compounds and xenobiotics across the plasma membrane. They are conserved from bacteria to mammals, with different numbers of genes within groups. Here, we present the first data on identification and functional characterization of Mate proteins in zebrafish (Danio rerio). Phylogenetic analysis revealed six Mates in teleost fish, annotated as Mate3-8, which form a distinct cluster separated from the tetrapod MATEs/Mates. Synteny analysis showed that zebrafish mate genes are orthologous to human MATEs. Gene expression analysis revealed that all the mate transcripts were constitutively and differentially expressed during embryonic development, followed by pronounced and tissue-specific expression in adults. Functional analyses were performed using transport activity assays with model substrates after heterologous overexpression of five zebrafish Mates in HEK293T cells. The results showed that zebrafish Mates interact with both physiological and xenobiotic substances but also substantially differ with respect to the interacting compounds and interaction strength in comparison to mammalian MATEs/Mates. Taken together, our data clearly indicate a potentially important role for zebrafish Mate transporters in zebrafish embryos and adults and provide a basis for detailed functional characterizations of single zebrafish Mate transporters. PMID:27357367

  6. Thyroid disruption in zebrafish (Danio rerio) larvae: Different molecular response patterns lead to impaired eye development and visual functions.

    PubMed

    Baumann, Lisa; Ros, Albert; Rehberger, Kristina; Neuhauss, Stephan C F; Segner, Helmut

    2016-03-01

    The vertebrate thyroid system is important for multiple developmental processes, including eye development. Thus, its environmentally induced disruption may impact important fitness-related parameters like visual capacities and behaviour. The present study investigated the relation between molecular effects of thyroid disruption and morphological and physiological changes of eye development in zebrafish (Danio rerio). Two test compounds representing different molecular modes of thyroid disruption were used: propylthiouracil (PTU), which is an enzyme-inhibitor of thyroid hormone synthesis, and tetrabromobisphenol A (TBBPA), which interacts with the thyroid hormone receptors. Both chemicals significantly altered transcript levels of thyroid system-related genes (TRα, TRβ, TPO, TSH, DIO1, DIO2 and DIO3) in a compound-specific way. Despite these different molecular response patterns, both treatments resulted in similar pathological alterations of the eyes such as reduced size, RPE cell diameter and pigmentation, which were concentration-dependent. The morphological changes translated into impaired visual performance of the larvae: the optokinetic response was significantly and concentration-dependently decreased in both treatments, together with a significant increase of light preference of PTU-treated larvae. In addition, swimming activity was impacted. This study provides first evidence that different modes of molecular action of the thyroid disruptors can be associated with uniform apical responses. Furthermore, this study is the first to show that pathological eye development, as it can be induced by exposure to thyroid disruptors, indeed translates into impaired visual capacities of zebrafish early life stages. PMID:26765085

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

    PubMed

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

    2014-11-01

    The aim of the present study was to investigate the effects of the androgenic endocrine disruptor 17β-trenbolone on the sexual development of zebrafish (Danio rerio) with special emphasis on the question of whether adverse outcomes of developmental exposure are reversible or persistent. An exposure scenario including a recovery phase was chosen to assess the potential reversibility of androgenic effects. Zebrafish were exposed to environmentally relevant concentrations of 17β-trenbolone (1 ng/L-30 ng/L) from fertilization until completion of gonad sexual differentiation (60 d posthatch). Thereafter, exposure was either followed by 40 d of recovery in clean water or continued until 100 d posthatch, the age when zebrafish start being able to reproduce. Fish exposed for 100 d to 10 ng/L or 30 ng/L 17β-trenbolone were masculinized at different biological effect levels, as evidenced from a concentration-dependent shift of the sex ratio toward males as well as a significantly increased maturity of testes. Gonad morphological masculinization occurred in parallel with decreased vitellogenin concentrations in both sexes. Changes of brain aromatase (cyp19b) mRNA expression showed no consistent trend with respect to either exposure duration or concentration. Gonad morphological masculinization as well as the decrease of vitellogenin persisted after depuration over 40 d in clean water. This lack of recovery suggests that androgenic effects on sexual development of zebrafish are irreversible. PMID:25070268

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

    PubMed

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

    2014-08-01

    The aim of the present study was to investigate the persistence of the feminizing effects of discontinued 17α-ethinylestradiol (EE2) exposure on zebrafish (Danio rerio). An exposure scenario covering the sensitive phase of sexual differentiation, as well as final gonad maturation was chosen to examine the estrogenic effects on sexual development of zebrafish. Two exposure scenarios were compared: continuous exposure to environmentally relevant concentrations (0.1-10 ng/L EE2) up to 100 days post-hatch (dph) and developmental exposure up to 60 dph, followed by 40 days of depuration in clean water. The persistence of effects was investigated at different biological organization levels from mRNA to population-relevant endpoints to cover a broad range of important parameters. EE2 had a strong feminizing and inhibiting effect on the sexual development of zebrafish. Brain aromatase (cyp19b) mRNA expression showed no clear response, but vitellogenin levels were significantly elevated, gonad maturation and body growth were inhibited in both genders, and sex ratios were skewed towards females and undifferentiated individuals. To a large extent, all of these effects were reversed after 40 days of recovery, leading to the conclusion that exposure to the estrogen EE2 results in very strong, but reversible underdevelopment and feminization of zebrafish. The present study is the first to show this reversibility at different levels of organization, which gives better insight into the mechanistic basis of estrogenic effects in zebrafish. PMID:24832493

  9. Developmental toxicity and endocrine disruption of naphthenic acids on the early life stage of zebrafish (Danio rerio).

    PubMed

    Wang, Jie; Cao, Xiaofeng; Huang, Yi; Tang, Xiaoyan

    2015-12-01

    Oil sands process-affected water (OSPW) has been reported to exhibit adverse effects on the environment and wildlife. Although the compounds responsible are unknown, naphthenic acids (NAs) have been considered to be implicated. The current study was designed to investigate whether NAs might cause developmental toxicity and endocrine disruption on the early life stage of zebrafish (Danio rerio). The success of embryo hatch was inhibited by 2.5 mg l(-1) oil sands NAs (OS-NAs) exposure, and both OSPW NAs and commercial NAs (C-NAs) exposure resulted in a variety of developmental lesions in the fish larvae, such as yolk sac edema, pericardial edema and spinal malformation. The transcription of genes involved cytochrome P450 aromatase (CYP19a and CYP19b), estrogen receptors (ERα, ERβ1 and ERβ2), and vitellogenin (VTG) was analyzed to evaluate the endocrine disrupting effects of NAs. Significant up-regulated gene expressions of CYP19b, ERα and VTG were observed in both OS-NAs and C-NAs groups, which indicated the deleteriously estrogenic potential of NAs. These results confirmed that NAs derived from crude petroleum could negatively impact the development and endocrine function of zebrafish, and be primarily responsible for the toxicity of OSPW. PMID:25995127

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  11. The effects of environmental enrichment and age-related differences on inhibitory avoidance in zebrafish (Danio rerio Hamilton).

    PubMed

    Manuel, Remy; Gorissen, Marnix; Stokkermans, Mitchel; Zethof, Jan; Ebbesson, Lars O E; van de Vis, Hans; Flik, Gert; van den Bos, Ruud

    2015-04-01

    The inhibitory avoidance paradigm allows the study of mechanisms underlying learning and memory formation in zebrafish (Danio rerio Hamilton). For zebrafish, the physiology and behavior associated with this paradigm are as yet poorly understood. We therefore assessed the effects of environmental enrichment and fish age on inhibitory avoidance learning. Fish raised in an environmentally enriched tank showed decreased anxiety-like behavior and increased exploration. Enrichment greatly reduced inhibitory avoidance in 6-month (6M)- and 12-month (12 M)-old fish. Following inhibitory avoidance, telencephalic mRNA levels of proliferating cell nuclear antigen (pcna), neurogenic differentiation (neurod), cocaine- and amphetamine-regulated transcript 4 (cart4), and cannabinoid receptor 1 (cnr1) were lower in enriched-housed fish, while the ratios of mineralocorticoid receptor (nr3c2)/glucocorticoid receptor α [nr3c1(α)] and glucocorticoid receptor β [nr3c1(β)]/glucocorticoid receptor α [nr3c1(α)] were higher. This was observed for 6M-old fish only, not for 24-month (24 M) old fish. Instead, 24 M-old fish showed delayed inhibitory avoidance, no effects of enrichment, and reduced expression of neuroplasticity genes. Overall, our data show strong differences in inhibitory avoidance behavior between zebrafish of different ages and a clear reduction in avoidance behavior following housing under environmental enrichment.

  12. Effects of the Dietary ω3:ω6 Fatty Acid Ratio on Body Fat and Inflammation in Zebrafish (Danio rerio).

    PubMed

    Powell, Mickie L; Pegues, Melissa A; Szalai, Alexander J; Ghanta, Vithal K; D'Abramo, Louis R; Watts, Stephen A

    2015-08-01

    The diets of populations in industrialized nations have shifted to dramatically increased consumption of ω6 polyunsaturated fatty acids (PUFA), with a corresponding decrease in the consumption of ω3 PUFA. This dietary shift may be related to observed increases in obesity, chronic inflammation, and comorbidities in the human population. We examined the effects of ω3:ω6 fatty acid ratios in the context of constant total dietary lipid on the growth, total body fat, and responses of key inflammatory markers in adult zebrafish (Danio rerio). Zebrafish were fed diets in which the ω3:ω6 PUFA ratios were representative of those in a purported ancestral diet (1:2) and more contemporary Western diets (1:5 and 1:8). After 5 mo, weight gain (fat free mass) of zebrafish was highest for those that received the 1:8 ratio treatment, but total body fat was lowest at this ratio. Measured by quantitative real-time RT-PCR, mRNA levels from liver samples of 3 chronic inflammatory response genes (C-reactive protein, serum amyloid A, and vitellogenin) were lowest at the 1:8 ratio. These data provide evidence of the ability to alter zebrafish growth and body composition through the quality of dietary lipid and support the application of this model to investigations of human health and disease related to fat metabolism.

  13. Zebrafish (Danio rerio) as a model for investigating dietary toxic effects of deoxynivalenol contamination in aquaculture feeds.

    PubMed

    Sanden, Monica; Jørgensen, Susanne; Hemre, Gro-Ingunn; Ørnsrud, Robin; Sissener, Nini H

    2012-12-01

    The effects of feeding six diets spiked with increasing levels of DON for 45 days to zebrafish (Danio rerio) on performance and liver gene biomarkers were investigated. In addition long term effects on fecundity, offspring larvae swimming activity and global DNA methylation in embryos were investigated. Zebrafish performance was not affected. Liver CYP1A mRNA levels were significantly higher in fish fed 2.0 ppm DON compared to the control group, 0.1, 0.5 and 1.5 ppm group. Gene transcripts of CuZn SOD and Cyclin G1 increased with increasing content of dietary DON. The percentage of 5-methylcytosine in embryos did not differ and was 7.0-7.1% across the groups. Fecundity showed a biphasic response pattern. Interestingly, fish fed 1.5 ppm DON had 22% higher fecundity compared to control. A trend towards increased larvae swimming activity was seen in the high DON group. Our data suggest that DON is detoxified in the liver through the phase 1 system resulting in a disturbance in the oxidative balance. We do not know if effects observed on fecundity and larvae swimming activity are attributed to a direct interaction of DON with the reproductive organ or secondary to the maternal/paternal liver oxidative imbalance.

  14. Molecular cloning and functional characterization of a high-affinity zinc importer (DrZIP1) from zebrafish (Danio rerio).

    PubMed

    Qiu, Andong; Shayeghi, Majid; Hogstrand, Christer

    2005-06-15

    Zinc is a vital micronutrient to all organisms and a potential toxicant to aquatic animals. It is therefore of importance to understand the mechanism of zinc regulation. In the present study, we molecularly cloned and functionally characterized a zinc transporter of the SLC39A family [commonly referred to as the ZIP (Zrt- and Irt-related protein) family] from the gill of zebrafish (Danio rerio) (DrZIP1). DrZIP1 protein was found to localize at the plasma membrane and to function as a zinc uptake transporter when being expressed in either chinook salmon (Oncorhynchus tshawytscha) embryonic 214 cells or Xenopus laevis oocytes. In comparison with pufferfish transporter proteins (FrZIP2 and FrECaC) that are known to facilitate cellular zinc uptake, DrZIP1 appears to have high affinity to bind and transport zinc, suggesting that it maybe a high-affinity zinc uptake transporter (Km < 0.5 microM) in fish. Orthologues of DrZIP1 were also identified in both freshwater and seawater pufferfish (Tetraodon nigroviridis and Takifugu rubripes), indicating that these proteins may be functionally conserved among different fish species. DrZIP1 mRNA is expressed in all the tissues examined in the present study and thus DrZIP1 may be a constitutive zinc uptake transporter in many cell types of zebrafish.

  15. Comparison of zebrafish (Danio rerio) and fathead minnow (Pimephales promelas) as test species in the Fish Sexual Development Test (FSDT).

    PubMed

    Holbech, Henrik; Kinnberg, Karin L; Brande-Lavridsen, Nanna; Bjerregaard, Poul; Petersen, Gitte I; Norrgren, Leif; Orn, Stefan; Braunbeck, Thomas; Baumann, Lisa; Bomke, Christiane; Dorgerloh, Michael; Bruns, Eric; Ruehl-Fehlert, Christine; Green, John W; Springer, Timothy A; Gourmelon, Anne

    2012-03-01

    Results are presented from a validation (with 5 laboratories) of the Fish Sexual Development Test (FSDT) developed to detect endocrine disrupters (EDs) and included in the OECD (Organisation for Economic Co-operation and Development) working program. The aromatase-inhibiting fungicide prochloraz was tested in zebrafish (Danio rerio) and fathead minnow (Pimephales promelas). The fish were exposed during sexual differentiation and development from 0 to 60 days post hatch (dph). After exposure, the vitellogenin (VTG) concentrations were quantified in head/tail homogenate and the sex ratio was determined (defined as female, male, intersex or undifferentiated). NOEC/LOEC and EC(x) designs were compared to optimize the test approach. Results show that both species are highly sensitive to prochloraz during sexual development. They respond by skewing of the sex ratio towards male phenotype and by a VTG decline in females. The NOEC/LOEC approach is preferred because sex ratio is difficult to analyze with a regression model. The mean NOEC/LOEC for prochloraz on the sex ratio was 43.3/134 μg/L and 101/293 μg/L for zebrafish and fathead minnow, respectively. The mean NOEC/LOEC on the decline in female VTG concentration was 65/110 μg/L and ~30/68 μg/L respectively. In conclusion, zebrafish and fathead minnow are suitable species in the FSDT and their sexual differentiation is equally labile to EDs. PMID:22115822

  16. Alterations along the Hypothalamic-Pituitary-Thyroid Axis of the Zebrafish (Danio rerio) after Exposure to Propylthiouracil

    PubMed Central

    Schmidt, Florian; Braunbeck, Thomas

    2011-01-01

    In the past, various approaches have been developed to detect adverse effects of pollutants on the thyroid of vertebrates, most of these with special emphasis on the South African clawed frog, Xenopus laevis. Although fish are primarily affected by thyroid-disrupting chemicals, studies into alterations of the thyroid of fish are scarce. Therefore, effects of the reference compound propylthiouracil on histopathology of the thyroid axis were analyzed in a modified early life-stage test with zebrafish (Danio rerio) exposed to propylthiouracil. The test substance induced dose-dependent alterations of thyroidal tissue concomitant with increases in the number of surrounding blood vessels. Despite this massive proliferation of the thyroid, zebrafish were not able to maintain thyroxin concentrations. The pituitary was affected displaying significant alterations in thyroid-stimulating hormone cell counts. Quantitative evaluation of pituitary surface areas revealed a dose-dependent increase of adenohypophyseal tissue. Distinct histopathological effects may contribute to a more easy identification and interpretation of alterations induced by thyroid-disrupting chemicals. PMID:21860775

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

    PubMed

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

    2016-01-13

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

  18. Bisphenol A causes reproductive toxicity, decreases dnmt1 transcription, and reduces global DNA methylation in breeding zebrafish (Danio rerio)

    PubMed Central

    Laing, L. V.; Viana, J.; Dempster, E. L.; Trznadel, M.; Trunkfield, L. A.; Uren Webster, T. M.; van Aerle, R.; Paull, G. C.; Wilson, R. J.; Mill, J.; Santos, E. M.

    2016-01-01

    ABSTRACT Bisphenol A (BPA) is a commercially important high production chemical widely used in epoxy resins and polycarbonate plastics, and is ubiquitous in the environment. Previous studies demonstrated that BPA activates estrogenic signaling pathways associated with adverse effects on reproduction in vertebrates and that exposure can induce epigenetic changes. We aimed to investigate the reproductive effects of BPA in a fish model and to document its mechanisms of toxicity. We exposed breeding groups of zebrafish (Danio rerio) to 0.01, 0.1, and 1 mg/L BPA for 15 d. We observed a significant increase in egg production, together with a reduced rate of fertilization in fish exposed to 1 mg/L BPA, associated with significant alterations in the transcription of genes involved in reproductive function and epigenetic processes in both liver and gonad tissue at concentrations representing hotspots of environmental contamination (0.1 mg/L) and above. Of note, we observed reduced expression of DNA methyltransferase 1 (dnmt1) at environmentally relevant concentrations of BPA, along with a significant reduction in global DNA methylation, in testes and ovaries following exposure to 1 mg/L BPA. Our findings demonstrate that BPA disrupts reproductive processes in zebrafish, likely via estrogenic mechanisms, and that environmentally relevant concentrations of BPA are associated with altered transcription of key enzymes involved in DNA methylation maintenance. These findings provide evidence of the mechanisms of action of BPA in a model vertebrate and advocate for its reduction in the environment. PMID:27120497

  19. Ontogenetic development of the auditory sensory organ in zebrafish (Danio rerio): changes in hearing sensitivity and related morphology

    PubMed Central

    Wang, Jiping; Song, Qiang; Yu, Dongzhen; Yang, Guang; Xia, Li; Su, Kaiming; Shi, Haibo; Wang, Jian; Yin, Shankai

    2015-01-01

    Zebrafish (Danio rerio) is an important model organism in hearing research. However, data on the hearing sensitivity of zebrafish vary across different reports. In the present study, the hearing sensitivity of zebrafish was examined by analysing the auditory evoked potentials (AEPs) over a range of total lengths (TLs) from 12 to 46 mm. Morphological changes in the hair cells (HCs) of the saccule (the main auditory end organ) and their synapses with primary auditory neurons were investigated. The AEPs were detected up to a much higher frequency limit (12 kHz) than previously reported. No significant difference in the frequency response range was observed across the TL range examined. However, the AEP thresholds demonstrated both developmental improvement and age-related loss of hearing sensitivity. The changes in hearing sensitivity were roughly consistent with the morphological changes in the saccule including (1) the number and density of HCs, (2) the organization of stereocilia, and (3) the quantity of a main ribbon protein, Ribeye b. The results of this study established a clear baseline for the hearing ability of zebrafish and revealed that the changes in the saccule contribute to the observed changes in TL (age)-related hearing sensitivity. PMID:26526229

  20. Preliminary Evaluation on the Effects of Feeds on the Growth and Early Reproductive Performance of Zebrafish (Danio rerio)

    PubMed Central

    2012-01-01

    This study evaluated the effects of several commercially available feeds and different feeding regimes on the growth and early reproductive performance of zebrafish (Danio rerio). Juvenile zebrafish (n= 20; 5.06 ± 0.69 mg) were stocked into each of 24 tanks (volume, 2 L); 3 tanks were assigned to each of 8 feeding combinations for a period of 60 d. At the end of 60 d, 2 male and 2 female fish from each tank were pooled by dietary treatment (n = 6) and used to evaluate the effects of feeding combinations on early reproductive performance. Zebrafish fed dietary treatments 3 and 7 had significantly greater weight gain than zebrafish fed diet 5. Mean spawning success was significantly greater in zebrafish fed the control diet (Artemiaonly) than in those fed diet 1. Mean hatch rates were greater in zebrafish fed the control feed and diets 1, 2, 3, 5, and 6 than zebrafish fed diet 4. Additional results suggest that female zebrafish are sexually mature after 90 d post fertilization and that fertilization rates are the limiting factor in early reproduction. PMID:23043806

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

    PubMed

    Zheng, Feifei; Asim, Muhammad; Lan, Jiangfeng; Zhao, Lijuan; Wei, Shun; Chen, Nan; Liu, Xiaoling; Zhou, Yang; Lin, Li

    2015-01-01

    Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in fish. In this report, a MR gene (designated as zfMR) was cloned from zebra fish (Danio rerio), which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected zebra fish. The established zebra fish-A. sobria infection model will be valuable for elucidating the role of MR in fish immune responses to infection. PMID:25988382

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

    PubMed Central

    Zheng, Feifei; Asim, Muhammad; Lan, Jiangfeng; Zhao, Lijuan; Wei, Shun; Chen, Nan; Liu, Xiaoling; Zhou, Yang; Lin, Li

    2015-01-01

    Mannose receptor (MR) is a member of pattern-recognition receptors (PRRs), which plays a significant role in immunity responses. Much work on MR has been done in mammals and birds while little in fish. In this report, a MR gene (designated as zfMR) was cloned from zebra fish (Danio rerio), which is an attractive model for the studies of animal diseases. The full-length cDNA of zfMR contains 6248 bp encoding a putative protein of 1428 amino acids. The predicted amino acid sequences showed that zfMR contained a cysteine-rich domain, a single fibronectin type II (FN II) domain, eight C-type lectin-like domains (CTLDs), a transmembrane domain and a short C-terminal cytoplasmic domain, sharing highly conserved structures with MRs from the other species. The MR mRNA could be detected in all examined tissues with highest level in kidney. The temporal expression patterns of MR, IL-1β and TNF-α mRNAs were analyzed in the liver, spleen, kidney and intestine post of infection with Aeromonas sobria. By immunohistochemistry assay, slight enhancement of MR protein was also observed in the spleen and intestine of the infected zebra fish. The established zebra fish-A. sobria infection model will be valuable for elucidating the role of MR in fish immune responses to infection. PMID:25988382

  3. Growth, Oxygen Consumption, and Behavioral Responses of Danio rerio to Variation in Dietary Protein and Lipid Levels.

    PubMed

    O'Brine, Timothy M; Vrtělová, Jana; Snellgrove, Donna L; Davies, Simon J; Sloman, Katherine A

    2015-08-01

    In recent years, there has been increasing interest in the welfare of ornamental fish. Diet can significantly impact the welfare of fish, which can manifest as changes in the fish's physical health and behavior. The zebrafish, Danio rerio, is a popular ornamental species; however, little is known about their nutritional requirements with possible implications for their welfare. Here, we investigated the effect of diets with increasing crude protein (iso-caloric diets) and lipid (iso-nitrogenous diets) on the growth performance, oxygen consumption, and behavior of zebrafish. We found no significant effects of crude protein (32%-75%) or lipid (8%-16%) on the specific growth rate or oxygen consumption of fish fed 5% of their body mass (BM)/day, although the highest crude protein and lipid diet resulted in an increase in condition factor. Furthermore, the crude protein diets did not affect zebrafish behavior when fed a 2% BM ration, once a day. This study has shown that a diet with 32% crude protein and a diet with 8% crude lipid, when fed at a 5% BM ration, were sufficient to meet the growth requirements of our zebrafish. These diets supported the fish's physical health and thus benefited their welfare. PMID:26134575

  4. Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo

    PubMed Central

    Jaja-Chimedza, Asha; Gantar, Miroslav; Mayer, Gregory D.; Gibbs, Patrick D. L.; Berry, John P.

    2012-01-01

    Cyanobacteria (“blue-green algae”) are recognized producers of a diverse array of toxic secondary metabolites. Of these, the lipopolysaccharides (LPS), produced by all cyanobacteria, remain to be well investigated. In the current study, we specifically employed the zebrafish (Danio rerio) embryo to investigate the effects of LPS from geographically diverse strains of the widespread cyanobacterial genus, Microcystis, on several detoxifying enzymes/pathways, including glutathione-S-transferase (GST), glutathione peroxidase (GPx)/glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT), and compared observed effects to those of heterotrophic bacterial (i.e., E. coli) LPS. In agreement with previous studies, cyanobacterial LPS significantly reduced GST in embryos exposed to LPS in all treatments. In contrast, GPx moderately increased in embryos exposed to LPS, with no effect on reciprocal GR activity. Interestingly, total glutathione levels were elevated in embryos exposed to Microcystis LPS, but the relative levels of reduced and oxidized glutathione (i.e., GSH/GSSG) were, likewise, elevated suggesting that oxidative stress is not involved in the observed effects as typical of heterotrophic bacterial LPS in mammalian systems. In further support of this, no effect was observed with respect to CAT or SOD activity. These findings demonstrate that Microcystis LPS affects glutathione-based detoxification pathways in the zebrafish embryo, and more generally, that this model is well suited for investigating the apparent toxicophore of cyanobacterial LPS, including possible differences in structure-activity relationships between heterotrophic and cyanobacterial LPS, and teleost fish versus mammalian systems. PMID:22822454

  5. Study of effects of radio-wave frequency radiation emitted from cellular telephones on embryonic development of danio rerio

    NASA Astrophysics Data System (ADS)

    Vagula, Mary; Harkless, Ryan

    2013-05-01

    Radio wave frequency (RF) radiation emitted from cellular telephones has become increasingly ubiquitous as a result of the popularity of these phones. With the increasing and unavoidable exposure to RF radiation a reality, it is imperative that the effects of such radiation on living tissue be well understood. In particular, it is critical to understand any effects that RF radiation may have as a carcinogen and on embryonic development, as pregnant women are not exempt from such exposure. As a model organism, zebrafish (Danio rerio) have been studied extensively, and their value in studies of gene expression cannot be overstated. This study observed the effects of RF radiation on the embryonic development of zebrafish. The expression of two genes, shha and hoxb9a, that are key to the early development of the fish was examined. Both genes have homologs in humans as well as in other model organisms. Preliminary results suggest that exposure to cell phone radiation might have an effect on the expression of shha in zebrafish embryos, causing under expression. More trials are necessary to validate these results.

  6. Screening of Toxic Effects of Bisphenol A and Products of Its Degradation: Zebrafish (Danio rerio) Embryo Test and Molecular Docking.

    PubMed

    Makarova, Katerina; Siudem, Pawel; Zawada, Katarzyna; Kurkowiak, Justyna

    2016-10-01

    Bisphenol A (BPA) acts as an endocrine-disrupting compound even at a low concentration. Degradation of BPA could lead to the formation of toxic products. In this study, we compare the toxicity of BPA and seven intermediate products of its degradation. The accuracy of three molecular docking programs (Surflex, Autodock, and Autodock Vina) in predicting the binding affinities of selected compounds to human (ERα, ERβ, and ERRγ) and zebrafish (ERα, ERRγA, and ERRγB) estrogen and estrogen-related receptors was evaluated. The docking experiments showed that 4-isopropylphenol could have similar toxicity to that of BPA due to its high affinity to ERRγ and ERRγB and high octanol-water partitioning coefficient. The least toxic compounds were hydroquinone and phenol. Those compounds as well as BPA were screened in the zebrafish (Danio rerio) embryo test. 4-isopropylphenol had the strongest toxic effect on zebrafish embryos and caused 100% lethality shortly after exposure. BPA caused the delay in development, multiple deformations, and low heartbeats (30 bps), whereas hydroquinone had no impact on the development of the zebrafish embryo. Thus, the results of zebrafish screening are in good agreement with our docking experiment. The molecular docking could be used to screen the toxicity of other xenoestrogens and their products of degradation.

  7. Effects of urea on the molecules involved in the olfactory signal transduction: a preliminary study on Danio rerio.

    PubMed

    Ferrando, Sara; Gallus, Lorenzo; Gambardella, Chiara; Marchesotti, Emiliano; Ravera, Silvia; Franceschini, Valeria; Masini, Maria Angela

    2014-12-01

    Among vertebrates, the physiologically uremic Chondrichthyes are the only class which are not presenting the ciliated olfactory receptor neurons in the olfactory neuroepithelium. The only sequenced genome for this class revealed only three olfactory receptor genes and the immunohistochemical detection of G protein alpha subunit typically coupled to the olfactory receptors (Gα(olf)) failed in different species. Chronic renal disease can represent a cause of olfactory impairment in human. In this context, our present study focused on investigating potential effects of high urea concentration on the olfactory epithelium of vertebrates. Larvae of the teleost fish Danio rerio were exposed to urea in order to assess the effects on the olfactory signal transduction; in particular on both the olfactory receptors and the Gα(olf). The endocytosis of neutral red dye in the olfactory mucosa was detected in control and urea-exposed larvae. The amount of neutral red dye uptake was used as a marker of binding and internalization of the Gα(olf). The neutral red dye endocytosis was not affected by urea exposure, hence suggesting that the presence of the Gα(olf) and their binding to the odorants are not affected by urea treatment, either. The presence and distribution of Gα(olf) were investigated in the olfactory epithelium of control and urea-exposed larvae, using a commercial antibody. The immunoreactivity was increased after urea treatment, suggesting an effect of urea on the expression or degradation of this G protein alpha subunit.

  8. Ontogenetic development of the auditory sensory organ in zebrafish (Danio rerio): changes in hearing sensitivity and related morphology.

    PubMed

    Wang, Jiping; Song, Qiang; Yu, Dongzhen; Yang, Guang; Xia, Li; Su, Kaiming; Shi, Haibo; Wang, Jian; Yin, Shankai

    2015-11-03

    Zebrafish (Danio rerio) is an important model organism in hearing research. However, data on the hearing sensitivity of zebrafish vary across different reports. In the present study, the hearing sensitivity of zebrafish was examined by analysing the auditory evoked potentials (AEPs) over a range of total lengths (TLs) from 12 to 46 mm. Morphological changes in the hair cells (HCs) of the saccule (the main auditory end organ) and their synapses with primary auditory neurons were investigated. The AEPs were detected up to a much higher frequency limit (12 kHz) than previously reported. No significant difference in the frequency response range was observed across the TL range examined. However, the AEP thresholds demonstrated both developmental improvement and age-related loss of hearing sensitivity. The changes in hearing sensitivity were roughly consistent with the morphological changes in the saccule including (1) the number and density of HCs, (2) the organization of stereocilia, and (3) the quantity of a main ribbon protein, Ribeye b. The results of this study established a clear baseline for the hearing ability of zebrafish and revealed that the changes in the saccule contribute to the observed changes in TL (age)-related hearing sensitivity.

  9. 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. PMID:20874492

  10. Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

    2016-01-01

    Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (‑)-PCB149, and (+)-PCB149. Greater enrichment of (‑)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (‑)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149.

  11. Synergistic effects caused by atrazine and terbuthylazine on chlorpyrifos toxicity to early-life stages of the zebrafish Danio rerio.

    PubMed

    Pérez, Joanne; Domingues, Inês; Monteiro, Marta; Soares, Amadeu M V M; Loureiro, Susana

    2013-07-01

    This study examined the effects of three widely used pesticides that have been previously detected in aquatic systems neighbouring agricultural fields on the early-life stages of the zebrafish Danio rerio. Tests involving single exposures and binary combinations of the s-triazine herbicides (atrazine and terbuthylazine) and the organophosphate insecticide chlorpyrifos were performed. Several endpoints, such as swimming behaviour, morphological abnormalities and mortality, were studied. In addition, the inhibition of acetylcholinesterase (AChE) activity was investigated in order to evaluate the mode of action and toxicity of chlorpyrifos in the presence of these herbicides. Results indicate that both binary mixtures elicited synergistic responses on the swimming behaviour of zebrafish larvae. Moreover, although the herbicides were not effective inhibitors of the AChE on their own, a synergistic inhibition of the enzyme activity was obtained by exposure to mixtures with chlorpyrifos. We observed a correlation between impairment of swimming behaviour of the larvae and inhibition of AChE activity. This study supports previous studies concerning the risk assessment of mixtures since the toxicity may be underestimated when looking only at the single toxicants and not their mixtures.

  12. DNA damage and effects on glutathione-S-transferase activity induced by atrazine exposure in zebrafish (Danio rerio).

    PubMed

    Zhu, Lusheng; Dong, Xiaoli; Xie, Hui; Wang, Jun; Wang, Jinhua; Su, Jun; Yu, Changwei

    2011-10-01

    This study was undertaken to investigate the protective effect of atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-S-triazine) on the activity of glutathione-S-transferase (GST) and DNA damage in males and females of adult zebrafish (Danio rerio). Zebrafish were exposed to control and three treatments (0.01, 0.1, and 1 mg/L) of atrazine for 5, 10, 15, 20, and 25 days. The results indicated that, for males, the GST activity at lower atrazine concentrations (0.01 and 0.1 mg/L) was markedly higher than that of the controls throughout the duration of the experiment while there was a significant inhibition of the GST activity at 1 mg/L atrazine at days 5 and 20. For females, a significant increase was detected at 0.1 mg/L on the days 5 and 15 and at 0.01 mg/L on day 20. The DNA damage in zebrafish was evaluated using the comet assay; the olive tail moments obtained for hepatopancreas were enhanced after treatment with different concentrations of atrazine on days 5, 10, 15, 20, and 25. The DNA damage increased with increasing atrazine concentrations, indicating that genotoxicity of atrazine and significant differences was found compared to the controls. In conclusion, these findings provide further evidence of the effects of atrazine on aquatic ecosystems.

  13. Bioavailability and bioconcentration potential of perfluoroalkyl-phosphinic and -phosphonic acids in zebrafish (Danio rerio): Comparison to perfluorocarboxylates and perfluorosulfonates.

    PubMed

    Chen, Fangfang; Gong, Zhiyuan; Kelly, Barry C

    2016-10-15

    Currently, information regarding bioavailability and bioconcentration potential of perfluoroalkyl phosphinic acids (PFPiAs) in aquatic organisms does not exist. The main objective of the present study was to assess uptake and elimination kinetics of PFPiAs in zebrafish (Danio rerio) following aqueous exposure. The results showed that PFPiA exposure can result in very high steady-state bioconentration factors (BCFss), compared to perfluorocarboxylates and perfluorosulfonates.C6/C10 PFPiA exhibited the highest BCFss, ranging between 10(7) and 10(10), orders of magnitude higher than those for long-chain perfluorocarboxylates. Strong positive relationships were observed between BCFss versus the membrane-water distribution coefficient (Dmw) and the protein-water partition coefficient (Kpw) of the studied perfluoroalkyl substances. However, BCFss exhibited a substantial drop for the very hydrophobic PFPiAs (C8/C10 and C6/C12 PFPiAs). The reduced BCFss of these long-chain PFPiAs (perfluoroalkyl chain length=18; Dmw=10(9)) is likely the result of reduced bioavailability due to interaction with solute molecules/organic matter present in the water phase and/or reduced gill membrane permeability. While PFPiAs can be metabolized to perfluoroalkyl phosphonic acids, the metabolic transformation rate seems insufficient to counteract the high degree of uptake across gill membranes. These findings help to better understand exposure pathways and bioaccumulation behavior of these important perfluorinated acids in aquatic systems. PMID:27285794

  14. Teratogenicity of Ochratoxin A and the Degradation Product, Ochratoxin α, in the Zebrafish (Danio rerio) Embryo Model of Vertebrate Development

    PubMed Central

    Haq, Mehreen; Gonzalez, Nelson; Mintz, Keenan; Jaja-Chimedza, Asha; De Jesus, Christopher Lawrence; Lydon, Christina; Welch, Aaron Z.; Berry, John P.

    2016-01-01

    Ochratoxins, and particularly ochratoxin A (OTA), are toxic fungal-derived contaminants of food and other agricultural products. Growing evidence supports the degradation of OTA by chemical, enzymatic and/or microbial means as a potential approach to remove this mycotoxin from food products. In particular, hydrolysis of OTA to ochratoxin α (OTα) and phenylalanine is the presumptive product of degradation in most cases. In the current study, we employed the zebrafish (Danio rerio) embryo, as a model of vertebrate development to evaluate, the teratogenicity of OTA and OTα. These studies show that OTA is potently active in the zebrafish embryo toxicity assay (ZETA), and that toxicity is both concentration- and time-dependent with discernible and quantifiable developmental toxicity observed at nanomolar concentrations. On the other hand, OTα had no significant effect on embryo development at all concentrations tested supporting a decreased toxicity of this degradation product. Taken together, these results suggest that ZETA is a useful, and highly sensitive, tool for evaluating OTA toxicity, as well as its degradation products, toward development of effective detoxification strategies. Specifically, the results obtained with ZETA, in the present study, further demonstrate the toxicity of OTA, and support its degradation via hydrolysis to OTα as an effective means of detoxification. PMID:26861395

  15. Teratogenicity of Ochratoxin A and the Degradation Product, Ochratoxin α, in the Zebrafish (Danio rerio) Embryo Model of Vertebrate Development.

    PubMed

    Haq, Mehreen; Gonzalez, Nelson; Mintz, Keenan; Jaja-Chimedza, Asha; De Jesus, Christopher Lawrence; Lydon, Christina; Welch, Aaron; Berry, John P

    2016-02-01

    Ochratoxins, and particularly ochratoxin A (OTA), are toxic fungal-derived contaminants of food and other agricultural products. Growing evidence supports the degradation of OTA by chemical, enzymatic and/or microbial means as a potential approach to remove this mycotoxin from food products. In particular, hydrolysis of OTA to ochratoxin α (OTα) and phenylalanine is the presumptive product of degradation in most cases. In the current study, we employed the zebrafish (Danio rerio) embryo, as a model of vertebrate development to evaluate, the teratogenicity of OTA and OTα. These studies show that OTA is potently active in the zebrafish embryo toxicity assay (ZETA), and that toxicity is both concentration- and time-dependent with discernible and quantifiable developmental toxicity observed at nanomolar concentrations. On the other hand, OTα had no significant effect on embryo development at all concentrations tested supporting a decreased toxicity of this degradation product. Taken together, these results suggest that ZETA is a useful, and highly sensitive, tool for evaluating OTA toxicity, as well as its degradation products, toward development of effective detoxification strategies. Specifically, the results obtained with ZETA, in the present study, further demonstrate the toxicity of OTA, and support its degradation via hydrolysis to OTα as an effective means of detoxification. PMID:26861395

  16. Genomic organization of the zebrafish (Danio rerio) T cell receptor alpha/delta locus and analysis of expressed products.

    PubMed

    Seelye, Stacie L; Chen, Patricia L; Deiss, Thaddeus C; Criscitiello, Michael F

    2016-05-01

    In testing the hypothesis that all jawed vertebrate classes employ immunoglobulin heavy chain V (IgHV) gene segments in their T cell receptor (TCR)δ encoding loci, we found that some basic characterization was required of zebrafish TCRδ. We began by annotating and characterizing the TCRα/δ locus of Danio rerio based on the most recent genome assembly, GRCz10. We identified a total of 141 theoretically functional V segments which we grouped into 41 families based upon 70 % nucleotide identity. This number represents the second greatest count of apparently functional V genes thus far described in an antigen receptor locus with the exception of cattle TCRα/δ. Cloning, relative quantitative PCR, and deep sequencing results corroborate that zebrafish do express TCRδ, but these data suggest only at extremely low levels and in limited diversity in the spleens of the adult fish. While we found no evidence for IgH-TCRδ rearrangements in this fish, by determining the locus organization we were able to suggest how the evolution of the teleost α/δ locus could have lost IgHVs that exist in sharks and frogs. We also found evidence of surprisingly low TCRδ expression and repertoire diversity in this species. PMID:26809968

  17. Impact of environmental and genetic factors on the scale shape of zebrafish, Danio rerio (Hamilton 1822): a geometric morphometric study.

    PubMed

    Staszny, A; Havas, Enikő; Kovács, R; Urbányi, B; Paulovits, G; Bencsik, Dóra; Ferincz, A; Müller, T; Specziár, A; Bakos, Katalin; Csenki, Zs

    2013-12-01

    Intraspecific morphological variability may reflect either genetic divergence among groups of individuals or response of individuals to environmental circumstances within the frame of phenotypic plasticity. Several studies were able to discriminate wild fish populations based on their scale shape. Here we examine whether the variations in the scale shape in fish populations could be related to genetic or environmental factors, or to both of them. In the first experiment, two inbred lines of zebrafish, Danio rerio (Hamilton 1822) reared under identical environmental conditions were compared. Secondly, to find out what effect environmental factors might have, offsprings were divided into two groups and reared on different diets for 12 weeks. Potential recovery of scales from an environmental effect was also assessed. Experimental groups could successfully be distinguished according to the shape of scales in both experiments, and the results showed that both genetic and environmental factors may notably influence scale shape. It was concluded that scale shape analysis might be used as an explanatory tool to detect potential variability of environmental influences impacting genetically homogeneous groups of fish. However, due to its sensitivity to environmental heterogeneity, the applicability of this technique in identifying intraspecific stock membership of fish could be limited.

  18. Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

    PubMed Central

    Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

    2016-01-01

    Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (−)-PCB149, and (+)-PCB149. Greater enrichment of (−)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (−)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149. PMID:26786282

  19. Bisphenol A causes reproductive toxicity, decreases dnmt1 transcription, and reduces global DNA methylation in breeding zebrafish (Danio rerio).

    PubMed

    Laing, L V; Viana, J; Dempster, E L; Trznadel, M; Trunkfield, L A; Uren Webster, T M; van Aerle, R; Paull, G C; Wilson, R J; Mill, J; Santos, E M

    2016-07-01

    Bisphenol A (BPA) is a commercially important high production chemical widely used in epoxy resins and polycarbonate plastics, and is ubiquitous in the environment. Previous studies demonstrated that BPA activates estrogenic signaling pathways associated with adverse effects on reproduction in vertebrates and that exposure can induce epigenetic changes. We aimed to investigate the reproductive effects of BPA in a fish model and to document its mechanisms of toxicity. We exposed breeding groups of zebrafish (Danio rerio) to 0.01, 0.1, and 1 mg/L BPA for 15 d. We observed a significant increase in egg production, together with a reduced rate of fertilization in fish exposed to 1 mg/L BPA, associated with significant alterations in the transcription of genes involved in reproductive function and epigenetic processes in both liver and gonad tissue at concentrations representing hotspots of environmental contamination (0.1 mg/L) and above. Of note, we observed reduced expression of DNA methyltransferase 1 (dnmt1) at environmentally relevant concentrations of BPA, along with a significant reduction in global DNA methylation, in testes and ovaries following exposure to 1 mg/L BPA. Our findings demonstrate that BPA disrupts reproductive processes in zebrafish, likely via estrogenic mechanisms, and that environmentally relevant concentrations of BPA are associated with altered transcription of key enzymes involved in DNA methylation maintenance. These findings provide evidence of the mechanisms of action of BPA in a model vertebrate and advocate for its reduction in the environment. PMID:27120497

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

    PubMed

    Kist, Luiza Wilges; Piato, Angelo Luis; da Rosa, João Gabriel Santos; Koakoski, Gessi; Barcellos, Leonardo José Gil; Yunes, João Sarkis; Bonan, Carla Denise; Bogo, Maurício Reis

    2011-01-01

    Microcystins (MCs) are toxins produced by cyanobacteria (blue-green algae), primarily Microcystis aeruginosa, forming water blooms worldwide. When an organism is exposed to environmental perturbations, alterations in normal behavioral patterns occur. Behavioral repertoire represents the consequence of a diversity of physiological and biochemical alterations. In this study, we assessed behavioral patterns and whole-body cortisol levels of adult zebrafish (Danio rerio) exposed to cell culture of the microcystin-producing cyanobacterium M. aeruginosa (MC-LR, strain RST9501). MC-LR exposure (100 μg/L) decreased by 63% the distance traveled and increased threefold the immobility time when compared to the control group. Interestingly, no significant alterations in the number of line crossings were found at the same MC-LR concentration and time of exposure. When animals were exposed to 50 and 100 μg/L, MC-LR promoted a significant increase (around 93%) in the time spent in the bottom portion of the tank, suggesting an anxiogenic effect. The results also showed that none of the MC-LR concentrations tested promoted significant alterations in absolute turn angle, path efficiency, social behavior, or whole-body cortisol level. These findings indicate that behavior is susceptible to MC-LR exposure and provide evidence for a better understanding of the ecological consequences of toxic algal blooms. PMID:22253623

  1. Development of a sensitive assay for the detection of Pseudoloma neurophilia in laboratory populations of the zebrafish Danio rerio

    PubMed Central

    Sanders, Justin L; Kent, Michael L

    2012-01-01

    Zebrafish (Danio rerio) are an increasingly important biological model in many areas of research. Diseases of zebrafish, especially those resulting in chronic, sub lethal infections, are of great concern due to the potential for non-protocol induced variation. The microsporidium, Pseudoloma neurophilia, is a common parasite of laboratory zebrafish. Current methods for detection of this parasite require lethal sampling of fish, which is often undesirable with poorly spawning mutant lines and small populations. We present here an improved molecular based diagnostic assay using real-time PCR, and including sonication treatment prior to DNA extraction. Sensitivity was increased compared to the previously published conventional PCR-based assay based on a dilution experiment, showing that this new assay had the ability to detect parasite DNA in one log higher dilution than the conventional PCR-based assay, which did not include sonication. Comparisons of several DNA extraction methods were also performed to determine the method providing the maximum sensitivity. Sonication was found to be the most effective method for disrupting spores. Further, we demonstrate the application of this method for testing of water, eggs and sperm, providing a potential non-lethal method for detection of this parasite in zebrafish colonies with a sensitivity of 10 spores per liter, 2 spores per egg and 10 spores per μl of sperm, respectively. PMID:22013754

  2. Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

    2016-01-01

    Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (-)-PCB149, and (+)-PCB149. Greater enrichment of (-)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (-)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149.

  3. Co-exposure of ZnO nanoparticles and UV radiation to Daphnia magna and Danio rerio: Combined effects rather than protection.

    PubMed

    Azevedo, Sofia L; Ribeiro, Fabianne; Jurkschat, Kerstin; Soares, Amadeu M V M; Loureiro, Susana

    2016-02-01

    The application of nanoparticles (NPs) in consumer products has been increasing over the past few years. Their release into the environment is likely to happen at any stage of production or during the use of products containing NPs. Zinc oxide NPs (ZnO-NP) are among the most-used NPs on the market due to its intrinsic properties, such as ultraviolet (UV) absorption. The aim of the present study was to assess the combined effects of ZnO-NP and UV radiation on 2 freshwater species: Daphnia magna and Danio rerio. The initial hypothesis was that the presence of ZnO-NP in the aquatic media would decrease the damaging effects of UV radiation for both species. The endpoints assessed for D. magna were immobilization, feeding inhibition, and reproduction output. For D. rerio, egg development was studied during 96 h and mortality, hatching delay, and abnormal development were the endpoints recorded. Combined exposures were designed based on the single toxicity of both stressors and analyzed based on the independent action concept and exploring possible deviations for synergism/antagonism, dose level, and dose ratio. Combined exposures with D. magna induced synergism on reproduction, decreasing the number of neonates produced more than expected based on both stressors' individual toxicity. Single exposures of D. rerio embryos to both stressors induced negative effects. The combined exposures caused a dose-ratio deviation pattern on mortality and hatching, with a synergism observed when ZnO-NP was the dominant stressor, changing to antagonism when UV radiation dominated the combined exposure. Regarding the results attained, studying ZnO toxicity under laboratory conditions may underestimate the risks when considering the potential interaction on effects when combined with UV radiation.

  4. Effects of tris (2-butoxyethyl) phosphate (TBOEP) on endocrine axes during development of early life stages of zebrafish (Danio rerio).

    PubMed

    Ma, Zhiyuan; Tang, Song; Su, Guanyong; Miao, Yueqiu; Liu, Hongling; Xie, Yuwei; Giesy, John P; Saunders, David M V; Hecker, Markus; Yu, Hongxia

    2016-02-01

    Due to phasing out of additive flame retardants such as polybrominated diphenyl ethers (PBDEs), Tris (2-butoxyethyl) phosphate (TBOEP) is widely used as a substitute. TBOEP is ubiquitous in the environment and has been measured at concentrations of micrograms per liter (μg L(-1)) in surface waters and wastewater. Information on potential adverse effects on development of aquatic organisms caused by exposure to environmentally relevant concentrations of TBOEP is limited, especially for effects that may be caused through impairment of endocrine-modulated homeostasis. Therefore, this study was conducted to determine effects of TBOEP on ontogeny and transcription profiles of genes along the hypothalamus-pituitary-thyroidal (HPT), hypothalamus-pituitary-adrenal (HPA), and hypothalamus-pituitary-gonadal (HPG) axes in embryos/larvae of zebrafish (Danio rerio). Exposure to TBOEP (2-5,000 μg L(-1)) from 3 h post-fertilization (hpf) to 120 hpf induced developmental malformations in zebrafish with a LC50 of 288.54 μg L(-1) at both 96 hpf and 120 hpf. The predicted no observed effect concentration (PNOEC) was 2.40 μg L(-1). Exposure to 2, 20, or 200 μg TBOEP L(-1) altered expression of genes involved in three major molecular pathways in a concentration-dependent manner after 120 hpf. TBOEP caused lesser expression of some genes involved in synthesis of hormones, such as (pomc and fshβ) as well as upregulating expression of some genes coding for receptors (thr, tshr, gr, mr, er and ar) in zebrafish larvae. These changes at the molecular level could result in alterations of endocrine function, which could result in edema or deformity and ultimately death. PMID:26547027

  5. iPhone® applications as versatile video tracking tools to analyze behavior in zebrafish (Danio rerio).

    PubMed

    Pittman, Julian T; Ichikawa, Katie M

    2013-05-01

    Zebrafish (Danio rerio) are emerging as a promising model organism for experimental studies relevant to biological psychiatry. The objective of this study was to develop a novel video-based movement tracking and analysis system to quantify behavioral changes following psychoactive drug exposure in zebrafish. We assessed the effects of withdrawal from chronic ethanol exposure, and subsequent administration of fluoxetine (Prozac®), buspirone (Buspar®), and diazepam (Valium) using two behavioral paradigms; the Novel Tank Diving Test and the Light/Dark Choice Assay. A video tracking system was developed using two Apple® applications (Apps) to quantify these behaviors. Data from zebrafish exposed to the above treatments are presented in this paper not only to exemplify behavioral alterations associated with chronic exposure, but also more importantly, to validate the video tracking system. Following withdrawal from chronic ethanol exposure, zebrafish exhibited dose/time-dependent anxiogenic effects; including reduced exploration and freezing behavior in the Novel Tank Diving Test, and preference for the dark area for the Light/Dark Choice Assay. In contrast, the above drug treatments had significant anxiolytic effects. We have developed a simple and cost-effective method of measuring zebrafish behavioral responses. The iPhone® Apps outlined in this study offer numerous flexible methods of data acquisition; namely, ease of identification and tracking of multiple animals, tools for visualization of the tracks, and calculation of a range of analysis parameters. Furthermore, the limited amount of time required for interpretation of the video data makes this a powerful high-throughput tool with potential applications for pre-clinical drug development. PMID:23558086

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

    SciTech Connect

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

    2014-11-01

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

  7. Chondroitin sulfate and keratan sulfate are the major glycosaminoglycans present in the adult zebrafish Danio rerio (Chordata-Cyprinidae).

    PubMed

    Souza, Aline R C; Kozlowski, Eliene O; Cerqueira, Vinicius R; Castelo-Branco, Morgana T L; Costa, Manoel L; Pavão, Mauro S G

    2007-12-01

    The zebrafish Danio rerio (Chordata-Cyprinidae) is a model organism frequently used to study the functions of proteoglycans and their glycosaminoglycan (GAG) chains. Although several studies clearly demonstrate the participation of these polymers in different biological and cellular events that take place during embryonic development, little is known about the GAGs in adult zebrafish. In the present study, the total GAGs were extracted from the whole fish by proteolytic digestion, purified by anion-exchange chromatography and characterized by electrophoresis after degradation with specific enzymes and/or by high-performance liquid chromatography (HPLC) analysis of the disaccharides. Two GAGs were identified: a low-molecular-weight chondroitin sulfate (CS) and keratan sulfate (KS), corresponding to approximately 80% and 20% of the total GAGs, respectively. In the fish eye, KS represents approximately 80% of total GAGs. Surprisingly, no heparinoid was detected, but may be present in the fish at concentrations lower than the limit of the method used. HPLC of the disaccharides formed after chondroitin AC or ABC lyase degradation revealed that the zebrafish CS is composed by DeltaUA-1-->3-GalNAc(4SO4) (59.4%), DeltaUA-1-->3-GalNAc(6SO4) (23.1%), and DeltaUA-1-->3-GalNAc (17.5%) disaccharide units. No disulfated disaccharides were detected. Immunolocalization on sections from zebrafish retina using monoclonal antibodies against CS4- or 6-sulfate showed that in the retina these GAGs are restricted to the outer and inner plexiform layers. This is the first report showing the presence of KS in zebrafish eye, and the structural characterization of CS and its localization in the zebrafish retina. Detailed information about the structure and tissue localization of GAGs is important to understand the functions of these polymers in this model organism.

  8. Ontogenetic changes in the toxicity and efficacy of the anaesthetic MS222 (tricaine methanesulfonate) in zebrafish (Danio rerio) larvae.

    PubMed

    Rombough, Peter J

    2007-10-01

    Median lethal (LC(50)) and effective (EC(50)) concentrations for 1-h and 24-h exposures to the anaesthetic MS222 (tricaine methanesulfonate) were determined for zebrafish Danio rerio larvae ranging in age from 3 days postfertilization (dpf) to 9 dpf. Cessation of heart beat was used as the indicator of death (LC(50)) while failure to respond to direct mechanical stimulation of the head region was taken as an indication of deep anaesthesia (EC(50)). 1-h LC(50)s, 1-h EC(50)s and 24-h EC(50)s all decreased gradually but significantly (all P<0.01) with age. Mean values for 1-h LC(50)s were 1633 mg L(-1) and 730 mg L(-1), respectively, for 3 dpf and 9 dpf larvae. Mean value for 1-h and 24-h EC(50)s were 106 mg L(-1) and 100 mg L(-1), respectively, at 3 dpf and 65 mg L(-1) and 31 mg L(-1), respectively, at 9 dpf. The gradual increase with age in sensitivity to the anaesthetic implied by these indicators is probably a reflection of ontogenetic changes in the activity of detoxification pathways. Mean values for the 24-h LC(50) also decreased significantly (P<0.001) with age, from 566 mg L(-1) at 3 dpf to 64 mg L(-1) at 9 dpf. However, unlike the other indicators, the decrease was not gradual but occurred in a step-like fashion with virtually all of the change occurring between 4 dpf and 7 dpf. This sharp increase in sensitivity coincides with the shift in the major site of systemic ionoregulatory activity from the skin to the gills. The implications of these ontogenetic changes in lethal and effective levels for researchers or others intending to use the anaesthetic with fish larvae are discussed.

  9. iPhone® applications as versatile video tracking tools to analyze behavior in zebrafish (Danio rerio).

    PubMed

    Pittman, Julian T; Ichikawa, Katie M

    2013-05-01

    Zebrafish (Danio rerio) are emerging as a promising model organism for experimental studies relevant to biological psychiatry. The objective of this study was to develop a novel video-based movement tracking and analysis system to quantify behavioral changes following psychoactive drug exposure in zebrafish. We assessed the effects of withdrawal from chronic ethanol exposure, and subsequent administration of fluoxetine (Prozac®), buspirone (Buspar®), and diazepam (Valium) using two behavioral paradigms; the Novel Tank Diving Test and the Light/Dark Choice Assay. A video tracking system was developed using two Apple® applications (Apps) to quantify these behaviors. Data from zebrafish exposed to the above treatments are presented in this paper not only to exemplify behavioral alterations associated with chronic exposure, but also more importantly, to validate the video tracking system. Following withdrawal from chronic ethanol exposure, zebrafish exhibited dose/time-dependent anxiogenic effects; including reduced exploration and freezing behavior in the Novel Tank Diving Test, and preference for the dark area for the Light/Dark Choice Assay. In contrast, the above drug treatments had significant anxiolytic effects. We have developed a simple and cost-effective method of measuring zebrafish behavioral responses. The iPhone® Apps outlined in this study offer numerous flexible methods of data acquisition; namely, ease of identification and tracking of multiple animals, tools for visualization of the tracks, and calculation of a range of analysis parameters. Furthermore, the limited amount of time required for interpretation of the video data makes this a powerful high-throughput tool with potential applications for pre-clinical drug development.

  10. Chronic exposure to low benzo[a]pyrene level causes neurodegenerative disease-like syndromes in zebrafish (Danio rerio).

    PubMed

    Gao, Dongxu; Wu, Meifang; Wang, Chonggang; Wang, Yuanchuan; Zuo, Zhenghong

    2015-10-01

    Previous epidemiological and animal studies report that exposure to environmental pollutant exposure links to neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Benzo[a]pyrene (BaP), a neurotoxic polycyclic aromatic hydrocarbon, has been increasingly released into the environment during recent decades. So far, the role of BaP on the development of neurodegenerative diseases remaind unclear. This study aimed to determine whether chronic exposure to low dose BaP would cause neurodegenerative disease-like syndromes in zebrafish (Danio rerio). We exposed zebrafish, from early embryogenesis to adults, to environmentally relevant concentrations of BaP for 230 days. Our results indicated that BaP decreased the brain weight to body weight ratio, locomotor activity and cognitive ability; induced the loss of dopaminergic neurons; and resulted in neurodegeneration. In addition, obvious cell apoptosis in the brain was found. Furthermore, the neurotransmitter levels of dopamine and 3,4-dihydroxyphenylacetic acid, the mRNA levels of the genes encoding dopamine transporter, Parkinson protein 7, phosphatase and tensin-induced putative kinase 1, ubiquitin carboxy-terminal hydrolase L1, leucine-rich repeat serine/threonine kinase 2, amyloid precursor protein b, presenilin 1 and presenilin 2 were significantly down-regulated by BaP exposure. These findings suggest that chronic exposure to low dose BaP could cause the behavioral, neuropathological, neurochemical, and genetic features of neurodegenerative diseases. This study provides clues that BaP may constitute an important environmental risk factor for neurodegenerative diseases in humans.

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

    SciTech Connect

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

    2014-08-01

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

  12. Effects of tris (2-butoxyethyl) phosphate (TBOEP) on endocrine axes during development of early life stages of zebrafish (Danio rerio).

    PubMed

    Ma, Zhiyuan; Tang, Song; Su, Guanyong; Miao, Yueqiu; Liu, Hongling; Xie, Yuwei; Giesy, John P; Saunders, David M V; Hecker, Markus; Yu, Hongxia

    2016-02-01

    Due to phasing out of additive flame retardants such as polybrominated diphenyl ethers (PBDEs), Tris (2-butoxyethyl) phosphate (TBOEP) is widely used as a substitute. TBOEP is ubiquitous in the environment and has been measured at concentrations of micrograms per liter (μg L(-1)) in surface waters and wastewater. Information on potential adverse effects on development of aquatic organisms caused by exposure to environmentally relevant concentrations of TBOEP is limited, especially for effects that may be caused through impairment of endocrine-modulated homeostasis. Therefore, this study was conducted to determine effects of TBOEP on ontogeny and transcription profiles of genes along the hypothalamus-pituitary-thyroidal (HPT), hypothalamus-pituitary-adrenal (HPA), and hypothalamus-pituitary-gonadal (HPG) axes in embryos/larvae of zebrafish (Danio rerio). Exposure to TBOEP (2-5,000 μg L(-1)) from 3 h post-fertilization (hpf) to 120 hpf induced developmental malformations in zebrafish with a LC50 of 288.54 μg L(-1) at both 96 hpf and 120 hpf. The predicted no observed effect concentration (PNOEC) was 2.40 μg L(-1). Exposure to 2, 20, or 200 μg TBOEP L(-1) altered expression of genes involved in three major molecular pathways in a concentration-dependent manner after 120 hpf. TBOEP caused lesser expression of some genes involved in synthesis of hormones, such as (pomc and fshβ) as well as upregulating expression of some genes coding for receptors (thr, tshr, gr, mr, er and ar) in zebrafish larvae. These changes at the molecular level could result in alterations of endocrine function, which could result in edema or deformity and ultimately death.

  13. Embryonic exposure to carbendazim induces the transcription of genes related to apoptosis, immunotoxicity and endocrine disruption in zebrafish (Danio rerio).

    PubMed

    Jiang, Jinhua; Wu, Shenggan; Wu, Changxing; An, Xuehua; Cai, Leiming; Zhao, Xueping

    2014-12-01

    Carbendazim is one of the most widespread environmental contaminant that can cause major concern to human and animal reproductive system. To date, very few studies have been conducted on the toxic effect of carbendazim in the non-target organism zebrafish (Danio rerio). The study presented here aimed to assess how carbendazim triggers apoptosis, immunotoxicity and endocrine disruption pathways in zebrafish during its embryo development. Our results demonstrated that the expression patterns of many key genes involved in cell apoptosis pathway (e.g. P53, Mdm2, Bbc3 and Cas8) were significantly up-regulated upon the exposure to carbendazim at the concentration of 500 μg/L, while the Bcl2 and Cas3 were down-regulated at the same concentration, interestingly, the expression level of Ogg1 decreased at all the exposure concentrations. It was also observed that the mRNA levels of CXCL-C1C, CCL1, IL-1b and TNFα which were closely related to the innate immune system, were affected in newly hatched zebrafish after exposed to different concentrations of carbendazim. Moreover, the expression of genes that are involved in the hypothalamic-pituitary-gonadal/thyroid (HPG/HPT) axis including VTG, ERα, ERβ2, Dio1, Dio2, Thraa and Thrb were all down-regulated significantly after the exposure to carbendazim. The expression levels of two cytochrome P450 aromatases CYP19a and CYP19b were increased significantly after 20 and 100 μg/L carbendazim exposure, respectively. Taken together, our results indicated that carbendazim had the potential to induce cell apoptosis and cause immune toxicity as well as endocrine disruption in zebrafish during the embryo developmental stage. The information presented here also help to elucidate the environmental risks caused by the carbendazim-induced toxicity in aquatic organisms.

  14. Enantioselectivity in Developmental Toxicity of rac-metalaxyl and R-metalaxyl in Zebrafish (Danio rerio) Embryo.

    PubMed

    Zhang, Yinjun; Zhang, Yi; Chen, An; Zhang, Wei; Chen, Hao; Zhang, Quan

    2016-06-01

    Enantioselectivity of chiral pesticides in environmental safety has attracted more and more attention. In this study, we evaluated the enantioselective toxicity of rac-metalaxyl and R-metalaxyl to zebrafish (Danio rerio) embryos through various malformations including pericardial edema, yolk sac edema, crooked body, and short tails. The results showed that there were significant differences in toxicity to zebrafish embryos caused by rac-metalaxyl and R-metalaxyl, and the LC50 s at 96 h are 416.41 (353.91, 499.29) mg · L(-1) and 320.650 (279.80, 363.46) mg · L(-1) , respectively. In order to explore the possible mechanism of the development defects, the genes involved in the hypothalamic-pituitary-gonadal axis (vtg1, vtg2, cyp17, cyp19a, cyp19b) and hypothalamic-pituitary-thyroid axis (dio1, dio2, nis, tg, tpo) were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). The results revealed that there were no significant differences in the expression of vtg1, vtg2, cyp17, cyp19a, and cyp19b after exposure to rac-metalaxyl. However, the expression of vtg1, cyp19a, and cyp19b decreased significantly after exposure to R-metalaxyl. And likewise, rac-metalaxyl only caused the upregulation of dio2, while R-metalaxyl suppressed the expression of dio1 and tpo and induced the expression of dio2 and nis. The change of gene expression may cause the enantioselectivity in developmental toxicity in zebrafish embryo. The data provided here will be helpful for us to comprehensively understand the potential ecological risks of the currently used chiral fungicides. Chirality 28:489-494, 2016. © 2016 Wiley Periodicals, Inc.

  15. Sex-specific transcriptional responses of the zebrafish (Danio rerio) brain selenoproteome to acute sodium selenite supplementation

    PubMed Central

    Benner, Maia J.; Settles, Matt L.; Murdoch, Gordon K.; Hardy, Ronald W.

    2013-01-01

    The potential benefits of selenium (Se) supplementation are currently under investigation for prevention of certain cancers and treatment of neurological disorders. However, little is known concerning the response of the brain to increased dietary Se under conditions of Se sufficiency, despite the majority of Se supplementation trials occurring in healthy, Se sufficient subjects. We evaluated the transcriptional response of Se-dependent genes, selenoproteins and the genes necessary for their synthesis (the selenoproteome), in the zebrafish (Danio rerio) brain to supplementation with nutritionally relevant levels of dietary Se (sodium selenite) during conditions of assumed Se sufficiency. We first used a microarray approach to analyze the response of the brain selenoproteome to dietary Se supplementation for 14 days and then assessed the immediacy and time-scale transcriptional response of the brain selenoproteome to 1, 7, and 14 days of Se supplementation by quantitative real-time PCR (qRT-PCR). The microarray approach did not indicate large-scale influences of Se on the brain transcriptome as a whole or the selenoproteome specifically; only one nonselenoproteome gene (si:ch73-44m9.2) was significantly differentially expressed. Our qRT-PCR results, however, indicate that increases of dietary Se cause small, but significant transcriptional changes within the brain selenoproteome, even after only 1 day of supplementation. These responses were dynamic over a short period of supplementation in a manner highly dependent on sex and the duration of Se supplementation. In nutritional intervention studies, it may be necessary to utilize methods such as qRT-PCR, which allow larger sample sizes, for detecting subtle transcriptional changes in the brain. PMID:23737534

  16. Density-dependent processes in the life history of fishes: evidence from laboratory populations of zebrafish Danio rerio.

    PubMed

    Hazlerigg, Charles R E; Lorenzen, Kai; Thorbek, Pernille; Wheeler, James R; Tyler, Charles R

    2012-01-01

    Population regulation is fundamental to the long-term persistence of populations and their responses to harvesting, habitat modification, and exposure to toxic chemicals. In fish and other organisms with complex life histories, regulation may involve density dependence in different life-stages and vital rates. We studied density dependence in body growth and mortality through the life-cycle of laboratory populations of zebrafish Danio rerio. When feed input was held constant at population-level (leading to resource limitation), body growth was strongly density-dependent in the late juvenile and adult phases of the life-cycle. Density dependence in mortality was strong during the early juvenile phase but declined thereafter and virtually ceased prior to maturation. Provision of feed in proportion to individual requirements (easing resource limitation) removed density dependence in growth and substantially reduced density dependence in mortality, thus indicating that 'bottom-up' effects act on growth as well as mortality, but most strongly on growth. Both growth and mortality played an important role in population regulation, with density-dependent growth having the greater impact on population biomass while mortality had the greatest impact on numbers. We demonstrate a clear ontogenic pattern of change in density-dependent processes within populations of a very small (maximum length 5 mm) fish, maintained in constant homogeneous laboratory conditions. The patterns are consistent with those distilled from studies on wild fish populations, indicating the presence of broad ontogenic patterns in density-dependent processes that are invariant to maximum body size and hold in homogeneous laboratory, as well as complex natural environments. PMID:22655056

  17. The role of aquaporin and tight junction proteins in the regulation of water movement in larval zebrafish (Danio rerio).

    PubMed

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

    2013-01-01

    Teleost fish living in freshwater are challenged by passive water influx; however the molecular mechanisms regulating water influx in fish are not well understood. The potential involvement of aquaporins (AQP) and epithelial tight junction proteins in the regulation of transcellular and paracellular water movement was investigated in larval zebrafish (Danio rerio). We observed that the half-time for saturation of water influx (K(u)) was 4.3±0.9 min, and reached equilibrium at approximately 30 min. These findings suggest a high turnover rate of water between the fish and the environment. Water influx was reduced by the putative AQP inhibitor phloretin (100 or 500 μM). Immunohistochemistry and confocal microscopy revealed that AQP1a1 protein was expressed in cells on the yolk sac epithelium. A substantial number of these AQP1a1-positive cells were identified as ionocytes, either H⁺-ATPase-rich cells or Na⁺/K⁺-ATPase-rich cells. AQP1a1 appeared to be expressed predominantly on the basolateral membranes of ionocytes, suggesting its potential involvement in regulating ionocyte volume and/or water flux into the circulation. Additionally, translational gene knockdown of AQP1a1 protein reduced water influx by approximately 30%, further indicating a role for AQP1a1 in facilitating transcellular water uptake. On the other hand, incubation with the Ca²⁺-chelator EDTA or knockdown of the epithelial tight junction protein claudin-b significantly increased water influx. These findings indicate that the epithelial tight junctions normally act to restrict paracellular water influx. Together, the results of the present study provide direct in vivo evidence that water movement can occur through transcellular routes (via AQP); the paracellular routes may become significant when the paracellular permeability is increased.

  18. Embryonic exposure to carbendazim induces the transcription of genes related to apoptosis, immunotoxicity and endocrine disruption in zebrafish (Danio rerio).

    PubMed

    Jiang, Jinhua; Wu, Shenggan; Wu, Changxing; An, Xuehua; Cai, Leiming; Zhao, Xueping

    2014-12-01

    Carbendazim is one of the most widespread environmental contaminant that can cause major concern to human and animal reproductive system. To date, very few studies have been conducted on the toxic effect of carbendazim in the non-target organism zebrafish (Danio rerio). The study presented here aimed to assess how carbendazim triggers apoptosis, immunotoxicity and endocrine disruption pathways in zebrafish during its embryo development. Our results demonstrated that the expression patterns of many key genes involved in cell apoptosis pathway (e.g. P53, Mdm2, Bbc3 and Cas8) were significantly up-regulated upon the exposure to carbendazim at the concentration of 500 μg/L, while the Bcl2 and Cas3 were down-regulated at the same concentration, interestingly, the expression level of Ogg1 decreased at all the exposure concentrations. It was also observed that the mRNA levels of CXCL-C1C, CCL1, IL-1b and TNFα which were closely related to the innate immune system, were affected in newly hatched zebrafish after exposed to different concentrations of carbendazim. Moreover, the expression of genes that are involved in the hypothalamic-pituitary-gonadal/thyroid (HPG/HPT) axis including VTG, ERα, ERβ2, Dio1, Dio2, Thraa and Thrb were all down-regulated significantly after the exposure to carbendazim. The expression levels of two cytochrome P450 aromatases CYP19a and CYP19b were increased significantly after 20 and 100 μg/L carbendazim exposure, respectively. Taken together, our results indicated that carbendazim had the potential to induce cell apoptosis and cause immune toxicity as well as endocrine disruption in zebrafish during the embryo developmental stage. The information presented here also help to elucidate the environmental risks caused by the carbendazim-induced toxicity in aquatic organisms. PMID:25304545

  19. Nrf2 and Nrf2-Related Proteins in Development and Developmental Toxicity: Insights from studies in Zebrafish (Danio rerio)

    PubMed Central

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

    2015-01-01

    Oxidative stress is an important mechanism of chemical toxicity, contributing to developmental toxicity and teratogenesis as well as to cardiovascular and neurodegenerative diseases and diabetic embryopathy. Developing animals are especially sensitive to effects of chemicals that disrupt the balance of processes generating reactive species and oxidative stress, and those anti-oxidant defenses that protect against oxidative stress. The expression and inducibility of anti-oxidant defenses through activation of NFE2-related factor 2 (Nrf2) and related proteins is an essential process affecting the susceptibility to oxidants, but the complex interactions of Nrf2 in determining embryonic response to oxidants and oxidative stress are only beginning to be understood. The zebrafish (Danio rerio) is an established model in developmental biology and now also in developmental toxicology and redox signaling. Here we review the regulation of genes involved in protection against oxidative stress in developing vertebrates, with a focus on Nrf2 and related cap’n’collar (CNC)-basic-leucine zipper (bZIP) transcription factors. Vertebrate animals including zebrafish share Nfe2, Nrf1, Nrf2, and Nrf3 as well as a core set of genes that respond to oxidative stress, contributing to the value of zebrafish as a model system with which to investigate the mechanisms involved in regulation of redox signaling and the response to oxidative stress during embryolarval development. Moreover, studies in zebrafish have revealed nrf and keap1 gene duplications that provide an opportunity to dissect multiple functions of vertebrate NRF genes, including multiple sensing mechanisms involved in chemical-specific effects. PMID:26130508

  20. Programming effects of high-carbohydrate feeding of larvae on adult glucose metabolism in zebrafish, Danio rerio.

    PubMed

    Fang, Liu; Liang, Xu-Fang; Zhou, Yi; Guo, Xiao-Ze; He, Yan; Yi, Ti-Lin; Liu, Li-Wei; Yuan, Xiao-Chen; Tao, Ya-Xiong

    2014-03-14

    The aim of the present study was to determine the potential long-term metabolic effects of early nutritional programming on carbohydrate utilisation in adult zebrafish (Danio rerio). High-carbohydrate diets were fed to fish during four ontogenetic stages: from the first-feeding stage to the end of the yolk-sac larval stage; from the first-feeding stage to 2 d after yolk-sac exhaustion; after yolk-sac exhaustion for 3 or 5 d. The carbohydrate stimuli significantly increased the body weight of the first-feeding groups in the short term. The expression of genes was differentially regulated by the early dietary intervention. The high-carbohydrate diets resulted in decreased plasma glucose levels in the adult fish. The mRNA levels and enzyme activities of glucokinase, pyruvate kinase, α-amylase and sodium-dependent glucose co-transporter 1 were up-regulated in the first-feeding groups. There was no significant change in the mRNA levels of glucose-6-phosphatase (G6Pase) in any experimental group, and the activity of G6Pase enzyme in the FF-5 (first feeding to 2 d after yolk-sac exhaustion) group was significantly different from that of the other groups. The expression of phosphoenolpyruvate carboxykinase gene in all the groups was significantly decreased. In the examined early programming range, growth performance was not affected. Taken together, data reported herein indicate that the period ranging from the polyculture to the external feeding stage is an important window for potential modification of the long-term physiological functions. In conclusion, the present study demonstrates that it is possible to permanently modify carbohydrate digestion, transport and metabolism of adult zebrafish through early nutritional programming.

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

    PubMed Central

    Spicer, Olivia Smith; Wong, Ten-Tsao; Zmora, Nilli; Zohar, Yonathan

    2016-01-01

    Gnrh is the major neuropeptide regulator of vertebrate reproduction, triggering a cascade of events in the pituitary-gonadal axis that result in reproductive competence. Previous research in mice and humans has demonstrated that Gnrh/GNRH null mutations result in hypogonadotropic hypogonadism and infertility. The goal of this study was to eliminate gnrh3 (the hypophysiotropic Gnrh form) function in zebrafish (Danio rerio) to determine how ontogeny and reproductive performance are affected, as well as factors downstream of Gnrh3 along the reproductive axis. Using the TALEN technology, we developed a gnrh3-/- zebrafish line that harbors a 62 bp deletion in the gnrh3 gene. Our gnrh3-/- zebrafish line represents the first targeted and heritable mutation of a Gnrh isoform in any organism. Using immunohistochemistry, we verified that gnrh3-/- fish do not possess Gnrh3 peptide in any regions of the brain. However, other than changes in mRNA levels of pituitary gonadotropin genes (fshb, lhb, and cga) during early development, which are corrected by adulthood, there were no changes in ontogeny and reproduction in gnrh3-/- fish. The gnrh3-/- zebrafish are fertile, displaying normal gametogenesis and reproductive performance in males and females. Together with our previous results that Gnrh3 cell ablation causes infertility, these results indicate that a compensatory mechanism is being activated, which is probably primed early on upon Gnrh3 neuron differentiation and possibly confined to Gnrh3 neurons. Potential compensation factors and sensitive windows of time for compensation during development and puberty should be explored. PMID:27355207

  2. Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae.

    PubMed

    Acosta, Daiane da Silva; Danielle, Naissa Maria; Altenhofen, Stefani; Luzardo, Milene Dornelles; Costa, Patrícia Gomes; Bianchini, Adalto; Bonan, Carla Denise; da Silva, Rosane Souza; Dafre, Alcir Luiz

    2016-01-01

    Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water. PMID:27012768

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

    PubMed

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

    2014-05-01

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

  4. Gills are needed for ionoregulation before they are needed for O(2) uptake in developing zebrafish, Danio rerio.

    PubMed

    Rombough, Peter

    2002-06-01

    A variation on the classic ablation method was used to determine whether O(2) uptake or ionoregulation is the first to shift from the skin to the gills in developing zebrafish, Danio rerio. Zebrafish larvae, ranging in age from 3 to 21 days postfertilization, were prevented from ventilating their gills and forced to rely on cutaneous processes by exposing them to one of two anaesthetics (tricaine methanesulphonate or phenoxyethanol) or by embedding their gills in agar. They were then placed in solutions designed to compensate selectively for impaired O(2) uptake (42% O(2)), impaired ionoregulatory capacity (50% physiological saline) or impairment of both functions (42% O(2)+50% physiological saline). Survival under these conditions was compared with that in normoxic (21% O(2)) fresh water. Neither hyperoxia nor 50% physiological saline had any significant effect on the survival of newly hatched larvae (3 days postfertilization), suggesting that at this stage cutaneous exchange was sufficient to satisfy both ionoregulatory and respiratory requirements. At 7 days postfertilization, the skin still appeared capable of satisfying the O(2) requirements of larvae but not their ionoregulatory requirements. Physiological saline significantly improved survival at 7 days postfertilization; hyperoxia did not. At 14 days postfertilization, both hyperoxia and 50% saline significantly improved survival, indicating that at this stage gills were required for O(2) uptake as well as for ionoregulation. At 21 days postfertilization, only hyperoxia significantly improved survival. By this stage, larvae apparently are so dependent on gills for O(2) uptake that they suffocate before the effects of ionoregulatory impairment become apparent. Thus, it would appear that in zebrafish it is the ionoregulatory capacity of the skin not its ability to take up O(2) that first becomes limiting. This raises the possibility that ionoregulatory pressures may play a more important role in gill

  5. Zinc and cadmium accumulation in single zebrafish ( Danio rerio) embryos — A total reflection X-ray fluorescence spectrometry application

    NASA Astrophysics Data System (ADS)

    Mages, Margarete; Bandow, Nicole; Küster, Eberhard; Brack, Werner; von Tümpling, Wolf

    2008-12-01

    Trace metals such as Cadmium (Cd) and Zinc (Zn) are known to exhibit adverse effects on many aquatic organisms including early life stages of fish. In contact with contaminated sediment, fish eggs and embryos may be exposed to metals via the water phase as well as via direct contact with contaminated particles. This may result in body burdens that are difficult to predict and may vary according to individual micro scale exposure conditions. The highly sensitive total reflection X-ray fluorescence spectrometry (TXRF) may provide a tool to analyse individual embryos for internal contaminant concentrations and thus helps to develop a better understanding of dose-response relationships. To test this hypothesis, embryos of Danio rerio were exposed to Cd and Zn spiked sediment in different treatments applying an ion exchange resin for modification of bioavailable concentrations. The TXRF analysis indicated individual embryos with dramatically enhanced exposure compared to other individuals despite uniform exposure conditions on a macro scale. Ion exchanger reduced embryo Zn concentrations to values close to control value with a comparably low standard deviation. Cadmium concentrations in embryos were in the range of 4000 to 7000 µg/g with a median of 5740 µg/g. A commercial ion exchanger reduced individual body burdens by a factor 50 to 100. Individual peak body burdens of up to 3160 µg/g were accompanied by reduced weight of the fish eggs due to early death i.e. coagulation. The investigation of exposure and effects on an individual-based scale may significantly help to reduce uncertainty and inconsistencies occurring in conventional analysis of pooled fish embryo samples.

  6. Comparison of the sensitivity of Danio rerio and Poecilia reticulata to silver nitrate in short-term tests.

    PubMed

    Doleželová, Petra; Mácová, Stanislava; Pištěková, Vladimíra; Svobodová, Zdeňka; Bedáňová, Iveta; Voslářová, Eva

    2008-09-01

    The aim of this study is to assess the acute toxicity of silver nitrate in adult zebra fish and adult guppies and to compare the sensitivity of these species to this compound. Silver is a naturally occurring element in our environment and it combines with other elements such as sulfide, chloride, and nitrate. Silver, in the form of silver nitrate, is one of the most toxic metals affecting freshwater fish. Industry, particularly photographical and electrotechnical, is the major contributor of silver that is released into the environment. Tests of acute toxicity were performed on the most common species of aquarium fish, Danio rerio and Poecilia reticulata. Both zebra fish and guppies were exposed to progressive concentrations of silver nitrate; a semi-static method according to OECD 203 was used. In each test series, 6 tests of acute toxicity were conducted, with 10 fish used for each separate concentration and for the control group. The results (number of fish deaths in the individual test concentrations) were subjected to probit analysis (EKO-TOX 5.1 software) to determine the 96hLC(50) AgNO(3) values. The 96hLC(50) AgNO(3) value for the zebra fish was (mean±SEM) 15±0.52 µg/l and for the guppies was (mean±SEM) 17.14±5.43 µg/l. We didn't find any statistically significant difference between the sensitivity of zebra fish and guppies. The results reported in this study are in agreement with LC(50) values published in peer-reviewed literature, and conclude that AgNO(3) is one of the most toxic compounds known to fishery. PMID:21218114

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

    PubMed

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

    2008-07-01

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

  8. Protective Yeasts Control V. anguillarum Pathogenicity and Modulate the Innate Immune Response of Challenged Zebrafish (Danio rerio) Larvae

    PubMed Central

    Caruffo, Mario; Navarrete, Natalie C.; Salgado, Oscar A.; Faúndez, Nelly B.; Gajardo, Miguel C.; Feijóo, Carmen G.; Reyes-Jara, Angélica; García, Katherine; Navarrete, Paola

    2016-01-01

    We investigated mechanisms involved in the protection of zebrafish (Danio rerio) larvae by two probiotic candidate yeasts, Debaryomyces hansenii 97 (Dh97) and Yarrowia lypolitica 242 (Yl242), against a Vibrio anguillarum challenge. We determined the effect of different yeast concentrations (104–107 CFU/mL) to: (i) protect larvae from the challenge, (ii) reduce the in vivo pathogen concentration and (iii) modulate the innate immune response of the host. To evaluate the role of zebrafish microbiota in protection, the experiments were performed in conventionally raised and germ-free larvae. In vitro co-aggregation assays were performed to determine a direct yeast-pathogen interaction. Results showed that both yeasts significantly increased the survival rate of conventionally raised larvae challenged with V. anguillarum. The concentration of yeasts in larvae tended to increase with yeast inoculum, which was more pronounced for Dh97. Better protection was observed with Dh97 at a concentration of 106 CFU/mL compared to 104 CFU/mL. In germ-free conditions V. anguillarum reached higher concentrations in larvae and provoked significantly more mortality than in conventional conditions, revealing the protective role of the host microbiota. Interestingly, yeasts were equally (Dh97) or more effective (Yl242) in protecting germ-free than conventionally-raised larvae, showing that protection can be exerted only by yeasts and is not necessarily related to modulation of the host microbiota. Although none of the yeasts co-aggregated with V. anguillarum, they were able to reduce its proliferation in conventionally raised larvae, reduce initial pathogen concentration in germ-free larvae and prevent the upregulation of key components of the inflammatory/anti-inflammatory response (il1b, tnfa, c3, mpx, and il10, respectively). These results show that protection by yeasts of zebrafish larvae challenged with V. anguillarum relates to an in vivo anti-pathogen effect, the modulation of

  9. Temperature- and exercise-induced gene expression and metabolic enzyme changes in skeletal muscle of adult zebrafish (Danio rerio)

    PubMed Central

    McClelland, Grant B; Craig, Paul M; Dhekney, Kalindi; Dipardo, Shawn

    2006-01-01

    Both exercise training and cold acclimatization induce muscle remodelling in vertebrates, producing a more aerobic phenotype. In ectothermic species exercise training and cold-acclimatization represent distinct stimuli. It is currently unclear if these stimuli act through a common mechanism or if different mechanisms lead to a common phenotype. The goal of this study was to survey responses that represent potential mechanisms responsible for contraction- and temperature-induced muscle remodelling, using an ectothermic vertebrate. Separate groups of adult zebrafish (Danio rerio) were either swim trained or cold acclimatized for 4 weeks. We found that the mitochondrial marker enzyme citrate synthase (CS) was increased by 1.5× in cold and by 1.3× with exercise (P < 0.05). Cytochrome c oxidase (COx) was increased by 1.2× following exercise training (P < 0.05) and 1.2× (P = 0.07) with cold acclimatization. However, only cold acclimatization increased β-hydroxyacyl-CoA dehydrogenase (HOAD) compared to exercise-trained (by 1.3×) and pyruvate kinase (PK) relative to control zebrafish. We assessed the whole-animal performance outcomes of these treatments. Maximum absolute sustained swimming speed (Ucrit) was increased in the exercise trained group but not in the cold acclimatized group. Real-time PCR analysis indicated that increases in CS are primarily transcriptionally regulated with exercise but not with cold treatments. Both treatments showed increases in nuclear respiratory factor (NRF)-1 mRNA which was increased by 2.3× in cold-acclimatized and 4× in exercise-trained zebrafish above controls. In contrast, peroxisome proliferator-activated receptor (PPAR)-α mRNA levels were decreased in both experimental groups while PPAR-β1 declined in exercise training only. Moreover, PPAR-γ coactivator (PGC)-1α mRNA was not changed by either treatment. In zebrafish, both temperature and exercise produce a more aerobic phenotype, but there are stimulus-dependent responses

  10. Toxicity of nitromusks in early lifestages of South African clawed frog (Xenopus laevis) and zebrafish (Danio rerio).

    PubMed

    Chou, Y J; Dietrich, D R

    1999-12-20

    Musk xylene (MX), musk ketone (MK) and musk moskene (MM) are synthetic nitro-containing fragrances. Due to their inherent lipophilicity and environmental persistence, they are frequently detected in environmental samples and especially in aquatic ecosystems. Despite this, the current environmental toxicity database of nitromusks is limited. Although nitromusks have been shown to accumulate in aquatic organisms, little is known about their potential developmental effects in the respective aquatic species. To investigate the developmental toxicity of these compounds to amphibians and fish, early lifestages of xenopus (Xenopus laevis) and zebrafish (Danio rerio) were exposed to three nitromusks for 96 h to examine the developmental effects of these compounds in the two species. Nitromusk body concentration measurements were carried out in parallel for correlation with potential developmental effects. No increased mortality, malformation or growth inhibition was observed in either species following 96-h exposure to 400 microg/l MX, MK and MM. However, an approximately 20% reduced viability was observed in xenopus larvae when exposed to 400 microg/l MX, MK and MM for 11 days. Xenopus and zebrafish e