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Sample records for rerio oryzias latipes

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

    PubMed

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

    2012-10-15

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

  2. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Immunoglobulin heavy chains in medaka (Oryzias latipes)

    PubMed Central

    2011-01-01

    Background Bony fish present an immunological system, which evolved independently from those of animals that migrated to land 400 million years ago. The publication of whole genome sequences and the availability of several cDNA libraries for medaka (Oryzias latipes) permitted us to perform a thorough analysis of immunoglobulin heavy chains present in this teleost. Results We identified IgM and IgD coding ESTs, mainly in spleen, kidney and gills using published cDNA libraries but we did not find any sequence that coded for IgT or other heavy chain isotypes described in fish. The IgM - ESTs corresponded with the secreted and membrane forms and surprisingly, the latter form only presented two constant heavy chain domains. This is the first time that this short form of membrane IgM is described in a teleost. It is different from that identified in Notothenioid teleost because it does not present the typical splicing pattern of membrane IgM. The identified IgD-ESTs only present membrane transcripts, with Cμ1 and five Cδ exons. Furthermore, there are ESTs with sequences that do not have any VH which disrupt open reading frames. A scan of the medaka genome using transcripts and genomic short reads resulted in five zones within a region on chromosome 8 with Cμ and Cδ exons. Some of these exons do not form part of antibodies and were at times interspersed, suggesting a recombination process between zones. An analysis of the ESTs confirmed that no antibodies are expressed from zone 3. Conclusions Our results suggest that the IGH locus duplication is very common among teleosts, wherein the existence of a recombination process explains the sequence homology between them. PMID:21676244

  4. 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 ...

  5. 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 ...

  6. Functional lysophosphatidic acid receptors expressed in Oryzias latipes.

    PubMed

    Morimoto, Yuji; Ishii, Shoichi; Ishibashi, Jun-Ichi; Katoh, Kazutaka; Tsujiuchi, Toshifumi; Kagawa, Nao; Fukushima, Nobuyuki

    2014-11-10

    Lysophosphatidic acid (LPA) signaling is known to play biological and pathophysiological roles in many types of animals. Medaka (Oryzias latipes) is an experimental fish that can be easily maintained, propagated, and analyzed, and whose genome has been completely sequenced. However, there is limited information available regarding medaka LPA receptors. Here, using information from the medaka genome database, we examine the genomic structures, expression, and functions of six LPA receptor genes, Lpar1-Lpar6. Our analyses reveal that the genomic structures of Lpar1 and Lpar4 are different from those deduced from the database. Functional analyses using a heterologous expression system demonstrate that all medaka LPA receptors except for LPA5b respond to LPA treatment with cytoskeletal changes. These findings provide useful information on the structure and function of medaka LPA receptor genes, and identify medaka as a useful experimental model for exploration of the biological significance of LPA signaling. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Biological (molecular and cellular) markers of toxicity. [Oryzias latipes

    SciTech Connect

    Shugart, L.R.

    1991-04-01

    The objective of this study is to evaluate the use of the Japanese Medaka (Oryzias latipes) as a predictor of genotoxicity following exposure to carcinogens. The early molecular events associated with genotoxicity in Medaka tissues following exposure to known carcinogens will be investigated. The primary endpoint for most small fish carcinogenesis studies is histopathogenic identification of a neoplastic lesion. Such lesions usually occur in the liver, and histogenesis of liver neoplasms in fish is similar to that in rodents. Because of the latent period between initial contact with chemical agents in the environmental and subsequent expression of deleterious effects, development of sensitive assays for detection and estimating early exposure is needed. Carcinogen-induced DNA damage will be assessed as a possible measure of severity of exposure, correlated with activation of liver enzymes. 6 refs., 2 figs., 1 tab.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

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

    PubMed Central

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

    2007-01-01

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

  15. Developmental effects of fipronil on Japanese Medaka (Oryzias latipes) embryos.

    PubMed

    Wagner, Scott D; Kurobe, Tomofumi; Hammock, Bruce G; Lam, Chelsea H; Wu, Gary; Vasylieva, Natalia; Gee, Shirley J; Hammock, Bruce D; Teh, Swee J

    2017-01-01

    Pesticides in urban runoff are a major source of pollutants in aquatic ecosystems. Fipronil, a phenylpyrazole insecticide, found in structural pest control products, turf grass control, and home pet flea medication, has recently increased in use and is commonly detected in urban runoff. However, little is known about the effects of fipronil on aquatic organisms at early developmental stages. Here, we evaluated toxicity of fipronil to embryos of Japanese Medaka (Oryzias latipes, Qurt strain) using a high-throughput 96-well plate toxicity test. Male and female embryos (<6 h post fertilization) were exposed to concentrations of fipronil ranging from 0.1 to 910 μg L(-1) for 14 days or until hatching. Embryos were subjected to gross and microscopic examinations of developmental adverse effects as well as transcriptome analysis using RNA-seq. Results indicated a positive dose-response in reduced hatching success, increased gross deformity (tail curvature) at a lowest-observed-effect concentration (LOEC) of 200 μg L(-1) and delayed hatching (∼1 day at the highest concentration, LOEC = 600 μg L(-1)). The transcriptome analysis indicated that fipronil exposure enhanced expression of titin and telethonin, which are responsible for muscle development. It is therefore possible that the formation of a tail curvature is due to asymmetrical overgrowth of muscle. Our results indicate that sub-lethal effects occur in embryonic stages of an aquatic vertebrate following exposure to high concentrations of fipronil, although no adverse effects at the highest published environmentally relevant concentration (6.3 μg L(-1)) were observed. Published by Elsevier Ltd.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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).

  1. Egg Development and Morphology of Larva and Juvenile of the Oryzias latipes.

    PubMed

    Lee, Sung-Hun; Kim, Chun-Cheol; Koh, Soo-Jin; Shin, Lim-Soo; Cho, Jae-Kwon; Han, Kyeong-Ho

    2014-09-01

    In order to monitor the developmental features of embryos, larvae, and juveniles of Oryzias latipes (Temminck and Schlegel), Oryzias latipes was caught in river of Shinduck-dong, Yeosu-si, Jeollanam-do, on May 2011, and experiments were carried out in Ichthyology laboratory at Chonnam National University. The blastodisc step was the first level for natural spawning. The optic vesicle, Kupffer's vesicle, myotome began to appear 75 hours 57 minutes later. After blastodisc development, the pectoral fins were made at 143 hours 37 minutes and the tail was separated started at the same time. Hatching was observed at 167 hours 27 minutes after blastodisc. The total length of the hatched larvae was 4.95~5.10 mm (mean, 5.01 mm), the mouth and anus were opened. Larvae used yolk completely after 3 days after hatching. The total length larvae was 5.45~5.56 mm (mean, 5.52 mm) after 8 days after hatching, and appeared the stems for tail. The stems pectoral, anal fin were showed after 14 days and the stems dorsal, ventral fin were appeared after 19 days. For 35 days after hatching, the total length of larvae 13.95~15.30 mm (mean, 14.64 mm), and at this time, fins and body were transferred like the adult Oryzias latipes.

  2. 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.

  3. 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

  4. Relationship Between Ice Nucleation Temperature Depression and Equilibrium Melting Points Depression of Medaka (Oryzias latipes) Embryos

    NASA Astrophysics Data System (ADS)

    Kimizuka, Norihito; Suzuki, Toru

    We measured the ice nucleation temperature depression , ΔTf , and equilibrium melting points depression, ΔTm, of Medaka (Oryzias latipes) embryos with different cryoprotectant (ethylene glycol, 1.3-propanediol, 1.4-butanediol, glycerol aqueous solutions) treatments. Our obtained results showed the good relationship between the ΔTf ,and ΔTm all samples. In addition the value of λ , which can be obtained from the linear relationship, ΔTf =λ ΔTm, were confirmed to show correlation with the value of λ , as obtained by the W/O emulsion method.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  8. 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

  9. Simplex PCR assay for positive identification of genetic sex in the Japanese medaka, Oryzias latipes.

    PubMed

    Patil, Jawahar G; Hinze, Susan J

    2008-01-01

    The medaka, Oryzias latipes, is a very popular model in biomedical research, particularly for elucidating sex differentiation and determination mechanisms and effects of endocrine disruptors among others. These studies require a sensitive, accurate, rapid, and reliable technique for genetic sexing of eggs, larvae, and adults. In this study, we report a simplex polymerase chain reaction approach that uses a single pair of primers for simultaneous amplification of sex-specific amplicons. Males and females yield a single diagnostic band of 933 and 1,906 bp, respectively, in three different strains of medaka tested, permitting gender identification accurately of both immature and adult fish. This technique will be useful in both ecological and biomedical researches that employ medaka and rely on genetic sexing.

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

    PubMed Central

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

    2000-01-01

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

  11. Biochemical characterization of the medaka (Oryzias latipes) orthologue for mammalian tissue-type transglutaminase (TG2).

    PubMed

    Takada, Yuki; Watanabe, Yuko; Okuya, Kazuho; Tatsukawa, Hideki; Hashimoto, Hisashi; Hitomi, Kiyotaka

    2017-03-01

    Transglutaminase is an enzyme family responsible for post-translational modification such as protein cross-linking and the attachment of primary amine and/or deamidation of glutamine-residue in proteins. Medaka (Oryzias latipes), a recently established model fish, has similar functional proteins to those characterized in mammals. Previously, we found the apparent orthologues that correspond to human transglutaminases in medaka. In this study, regarding the medaka orthologue of human tissue-type transglutaminase (OlTGT), recombinant protein was expressed in an active form in bacteria cultured at low temperature. Using the recombinant protein, we biochemically characterized the enzymatic activity and also obtained a monoclonal antibody that specifically recognized OlTGT. Immunochemical analysis revealed that OlTGT was not expressed ubiquitously, unlike its mammalian orthologue, but in primarily limited tissues such as the eye, brain, spinal cord, and gas gland.

  12. 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

  13. Uptake and depuration of the anti-depressant fluoxetine by the Japanese medaka (Oryzias latipes).

    PubMed

    Paterson, Gordon; Metcalfe, Chris D

    2008-12-01

    The selective serotonin reuptake inhibitor (SSRI) class of anti-depressants is among the most widely prescribed groups of pharmaceuticals. Consequently, aquatic ecosystems impacted by municipal wastewater discharges are predicted to receive substantial annual loadings of these compounds. Although SSRIs have been detected in fish tissues, little is known of their uptake and depuration in freshwater fish species. In this study, Japanese medaka (Oryzias latipes) were exposed to fluoxetine at a nominal concentration of 0.64 microg L(-1) for 7d and subsequently allowed to depurate in clean water over a 21d period. Fluoxetine uptake by medaka was observed within the first 5h of exposure and the biologically active metabolite, norfluoxetine, was also detected in medaka tissues during this timeframe. A maximum fluoxetine concentration was measured in medaka by the third day of the uptake phase, yielding an uptake rate constant (k(1)) of 5.9+/-0.5 (d(-1)). During the depuration phase of the experiment, a half life of 9.4+/-1.1d was determined for fluoxetine. Using these data, bioconcentration factor (BCF) values of 74 and 80 were estimated for fluoxetine and a pseudo-BCF (the ratio of the concentration of norfluoxetine in medaka and the aqueous fluoxetine concentration) of 117 was calculated for norfluoxetine. These results indicate longer persistence and greater potential for the bioaccumulation of fluoxetine and norfluoxetine in fish tissues than would be predicted from prior half life estimates derived using mammalian species.

  14. 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.

  15. Effects of ionization on the toxicity of silver nanoparticles to Japanese medaka (Oryzias latipes) embryos.

    PubMed

    Lee, Byoung-Cheun; Kim, Jungkon; Cho, Jae-Gu; Lee, Jae-Woo; Duong, Cuong N; Bae, Eunjoo; Yi, Jongheop; Eom, Ig-Chun; Choi, Kyunghee; Kim, Pilje; Yoon, Junheon

    2014-01-01

    Increase in the use of manufactured nanomaterials (NMs) has led to concerns about the environmental impacts. Especially, hazard of metal-based NMs is more severe due to ions released from surface by water quality parameters and physicochemical properties after entering into the water environment. However, little is known about the effects of ionization on the toxicity of metal-based NMs in the water environment. To address this question, we prepared the suspensions of silver nanoparticles (AgNP) at 25 μg L(-1) containing different concentrations of Ag(+) (5, 10, 20, 45, and 75% Ag(+) to total Ag), and evaluated their toxicity to Japanese medaka (Oryzias latipes) embryos. Higher Ag(+) ratios in the AgNP suspension, suggesting the lower number of particles, led to the higher adverse effects on embryos and sac-fries. In addition, histopathology analysis revealed that AgNPs penetrated through chorion of eggs and skin membrane, and were distributed into the tissues. The results imply that the ionization could decrease the toxicity of metal-based NMs in the water environment.

  16. 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.

  17. Psychotropic drugs in mixture alter swimming behaviour of Japanese medaka (Oryzias latipes) larvae above environmental concentrations.

    PubMed

    Chiffre, Axelle; Clérandeau, Christelle; Dwoinikoff, Charline; Le Bihanic, Florane; Budzinski, Hélène; Geret, Florence; Cachot, Jérôme

    2016-03-01

    Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics and antidepressors, are among the most prescribed active substances in the world. The occurrence of these compounds in the environment, as well as the adverse effects they can have on non-target organisms, justifies the growing concern about these emerging environmental pollutants. This study aims to analyse the effects of six psychotropic drugs, valproate, cyamemazine, citalopram, sertraline, fluoxetine and oxazepam, on the survival and locomotion of Japanese medaka Oryzias latipes larvae. Newly hatched Japanese medaka were exposed to individual compounds for 72 h, at concentrations ranging from 10 μg L(-1) to 10 mg L(-1). Lethal concentrations 50 % (LC50) were estimated at 840, 841 and 9,136 μg L(-1) for fluoxetine, sertraline and citalopram, respectively, while other compounds did not induce any significant increase in mortality. Analysis of the swimming behaviour of larvae, including total distance moved, mobility and location, provided an estimated lowest observed effect concentration (LOEC) of 10 μg L(-1) for citalopram and oxazepam, 12.2 μg L(-1) for cyamemazine, 100 μg L(-1) for fluoxetine, 1,000 μg L(-1) for sertraline and >10,000 μg L(-1) for valproate. Realistic environmental mixture of the six psychotropic compounds induced disruption of larval locomotor behaviour at concentrations about 10- to 100-fold greater than environmental concentrations.

  18. Unexpected effects of zinc pyrithione and imidacloprid on Japanese medaka fish (Oryzias latipes).

    PubMed

    Sánchez-Bayo, Francisco; Goka, Kouichi

    2005-09-30

    Biological effects of the biocide zinc pyrithione (Zpt), used in anti-dandruff shampoos and antifouling paints and the agricultural insecticide imidacloprid on Japanese medaka fish (Oryzias latipes) were assessed in experimental rice fields. Both chemicals are toxic to medaka, in particular Zpt, which also causes teratogenic effects such as spinal cord deformities in embryos at very low, sublethal concentrations. Rates of malformation in medaka fry from paddies treated twice a week with anti-dandruff shampoo (0.18-0.37 microL/L each time) over a period of 4 months were within the natural background, perhaps due to the quick dissipation rate of this chemical in the environment. Both Zpt and imidacloprid caused stress syndrome in juvenile medaka, with fish from Zpt-shampoo fields having a significantly lower weight to body length ratio than those from control fields. As it often happens with stressed fish, a massive infestation by a Trichodina ectoparasite was observed in medaka from imidacloprid fields. However, despite their high stress levels, fish from the Zpt fields did not suffer such infestation, supposedly because the disinfectant action of this biocide.

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

    PubMed

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

    2014-05-01

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

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

    USGS Publications Warehouse

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

    2000-01-01

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

  1. Influence of water hardening of the chorion on cadmium accumulation in medaka (Oryzias latipes) eggs.

    PubMed

    González-Doncel, Miguel; Larrea, Maite; Sánchez-Fortún, Sebastián; Hinton, David E

    2003-07-01

    This report describes a study in which in vitro fertilization methods were used to expose medaka (Oryzias latipes) eggs to cadmium (Cd(2+)). This approach was applied to address the differential sensitivity and cumulative potential of Cd(2+) when exposure was initiated early (before fertilization and water hardening of the chorion) versus later during embryo development (i.e., well after the chorion has undergone water hardening). Following range finding exposures (2.5, 10, 20, 40 or 80 mg/l) under artificially controlled experimental procedures, results from hatching success and embryo malformations showed the earlier exposure interval more sensitive than the assay involving only the embryonated egg. Subsequent accumulation studies have shown that the exposure initiated before fertilization apparently led to more Cd(2+) deposition in the chorion compared to the exposure during embryonated stages of the eggs. Similarly, values for total Cd(2+) indicated higher concentrations in those eggs exposed prior to--and during--water hardening. Results suggest an alteration of the properties of the zona radiata in the early-stage eggs, making it more permeable to the potential exit or entrance of waterborne agents even after water hardening. Ongoing studies must now address the development of more realistic exposure conditions of the gametes by using incubation media with osmolarities similar to surface waters, and by shortening duration for gamete exposure. Also, sensitive methods to localize Cd(2+) and to delineate the transfer from the chorion to the embryo are needed.

  2. Acute effects of triclosan, diclofenac and carbamazepine on feeding performance of Japanese medaka fish (Oryzias latipes).

    PubMed

    Nassef, Mohamed; Matsumoto, Shuhei; Seki, Masanori; Khalil, Fatma; Kang, Ik Joon; Shimasaki, Yohei; Oshima, Yuji; Honjo, Tsuneo

    2010-08-01

    The toxicity of three pharmaceutical and personal care products (PPCPs)--carbamazepine (CBMZ), diclofenac (DCF), and triclosan (TCS)--was examined by measuring their effects on feeding behavior and swimming speed of adult Japanese medaka fish (Oryzias latipes). Medaka were exposed to 6.15 mg L(-1) CBMZ, 1.0 mg L(-1) DCF, 0.17 mg L(-1) TCS, or no PPCP (control) for 9 d. Fish behaviors were monitored during days 5-9 of the exposure period. Feeding behavior (time to eat midge larvae, TE) and swimming speed (SS) of individual exposed and control fish were tracked in two dimensions, using an automated system with a digital charge-coupled device camera. As a result, feeding behavior was affected by exposure to CBMZ and DCF, while SS was altered by exposure to CBMZ and TCS. Thus, TCS, DCF and CBMZ appear to affect fish behaviors through different mechanisms. Overall, the results suggest that behavioral changes may provide a sensitive indicator for assessing the toxicity of PPCPs to aquatic organisms. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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

    2008-04-08

    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.

  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.

  6. 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.

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

    PubMed

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

    2016-04-07

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

  8. Embryotoxicity of extracts from Lake Ontario rainbow trout (Oncorhynchus mykiss) to Japanese medaka (Oryzias latipes)

    SciTech Connect

    Harris, G.E.; Metcalfe, T.L.; Metcalfe, C.D. . Environmental and Resources Studies Program); Huestis, S.Y. )

    1994-09-01

    Various preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogram-per-milliliter quantities, and polychlorinated dibenzo-p-dioxins and dibenzofurans were detected in picogram-per-milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non-ortho-substituted PCB congeners was embryo-toxic, whereas subfractions containing mono-ortho- and di-ortho-substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non-ortho-PCB subfraction. The non-ortho-PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non-ortho-PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non-ortho-substituted PCBs have the potential to be embryotoxic to early life stages of Great lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organic contaminants in Great Lakes salmonids.

  9. Identification of Robust Hypoxia Biomarker Candidates from Fin of Medaka (Oryzias latipes)✰

    PubMed Central

    Zhang, Ziping; Wells, Melissa C.; Boswell, Mikki G.; Beldorth, Ion; Kirk, Lyndsey M.; Wang, Yilei; Wang, Shulong; Savage, Markita; Walter, Ronald B.; Booth, Rachell E.

    2011-01-01

    Aquatic hypoxia caused by organic pollution and eutrophication is a pressing worldwide water pollution problem. Better methods for monitoring oxygen levels are needed to assist efforts to maintain and protect the health of natural aquatic environments. In this project, we used a Japanese ricefish (medaka, Oryzias latipes) 8K oligonucleotide array as a platform to identify potential hypoxic biomarkers in different organs (fin, gill, liver and brain) upon exposure to hypoxia. The microarray results were validated by qRT-PCR employing a subset of candidate biomarkers. Interestingly, the largest number and most significant of hypoxia responding array features were detected in hypoxia exposed fin tissues. We identified 173 array features that exhibited a significant response (over 2 fold change in expression) upon exposure to hypoxic conditions and validated a subset of these by quantitative RT-PCR. These gene targets were subjected to annotation and gene ontology mining. Positively identifiable gene targets that may be useful for development of a rapid and accurate biomarker test using fin clips are discussed in relation to previous reports on hypoxia responsive genes. PMID:21664487

  10. [Effects of extracorporeal ultrasound shockwaves on the relatively mature embryos of the teleost Oryzias latipes].

    PubMed

    Peters, N; Dahmen, G; Schmidt, W; Stein, F

    1998-04-01

    Exposure to low-energy ultrasound shock waves (1000 impulses at a frequency of 2/sec and an energy density of 0.08 mj/mm2; peak positive/negative pressure 16/-7 MPa; pulse duration about 10 musec) led to the following alterations in the cells and tissues of stage 35 embryos of Oryzias latipes ranked according to their extent: (1) In various tissues, especially in the trunk musculature, orthodox mitochondria were transformed into condensed (= low energy) mitochondria. (2) Nuclear envelopes and sarcoplasmatic reticulum of muscle fibres as well as endoplasmatic reticulum of epidermal ionocytes were often vesicularly dilated. (3) Muscle fibres in the trunk musculature began to separate from each other. Epidermal intercellular spaces were enlarged and increased in number. (4) Destruction of vessels and haematomas were observed in the circulatory system of the yolk sac. (5) Necroses up to total disintegration were found in various organs of the body cavity (intestine, liver, spleen). The less serious alterations (1 and 2) occurred in organs completely surrounded by other tissues. Major damages (4 and 5), however, affected only organs with free outer and inner surfaces, probably explained by cavitation and jet stream phenomena within the adjacent fluids.

  11. 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

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

    PubMed

    Sayed, Alaa El-Din Hamid; Mitani, Hiroshi

    2016-11-01

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

  13. 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

  14. 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.

  15. 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...

  16. 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...

  17. 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.

  18. Sperm motility initiation and duration in a euryhaline fish, medaka (Oryzias latipes).

    PubMed

    Yang, H; Tiersch, T R

    2009-08-01

    The medaka, Oryzias latipes, is a well-recognized fish model for biomedical research. An understanding of gamete characteristics is necessary for experimental manipulations such as artificial fertilization and sperm cryopreservation. The goal of this study was to investigate sperm characteristics of motility initiation, duration, and retention in medaka. First, motility was initiated by osmolality values ranging from 25 to 686mOsm/kg, which included deionized water and hypotonic, isotonic, and hypertonic Hanks' balanced salt solution. The percentage of motile sperm was >80% when osmolality was <315mOsm/kg and decreased as osmolality increased. This is different from most fish with external fertilization in which sperm motility can be initiated by hypotonic (for freshwater fish) or hypertonic (for marine fish) solutions or by altering the concentration of specific ions such as potassium (e.g., in salmonids). Second, upon activation, the sperm remained continuously motile, with reserve capacity, for as long as 1 wk during storage at 4 degrees C. This was also different from other externally fertilizing fish, in which motility is typically maintained for seconds to several minutes. Third, after changing the osmolality to 46 to 68 mOsm/kg by adding deionized water, the motility of sperm held at 274 to 500 mOsm/kg was higher than the original motility (P

  19. Toxicity of Desalination Brine of Varying Ionic Compositions on Embryonic Development of Japanese Medaka (Oryzias latipes)

    NASA Astrophysics Data System (ADS)

    Kupsco, A.; Schlenk, D.; Sikder, R.

    2016-02-01

    Desalination of seawater and brackish groundwater is a promising sustainable solution to meet growing water needs of California and throughout the US. However, the environmental impacts of brine disposal need to be evaluated. Brine disposal into freshwater embayments is often less dilute than disposal to coastal marine environments, resulting in a large increase in salinity. Fish embryos and larvae are especially sensitive to changes in salinity. Furthermore, different ionic compositions of different brine may vary in developmental toxicity. Limited research has been performed on the impacts of hypersalinity on chronic embryonic vertebrate development, particularly on sublethal adverse effects. To investigate these effects, embryos of Japanese medaka (Oryzias latipes), an euryhaline, model organism, were treated at fertilization with five treatments: 1. Freshwater; 2. Artificial seawater (17, 35, 42, 56, and 70 parts per thousand (ppth)); 3. Brine from a desalination facility at Monterey Bay Aquarium, CA, diluted 75%, 50%, and 25% with 35ppth artificial seawater to simulate mixing (39, 42, 46 and 50ppth); 4. River water modeled after the San Joaquin Valley, CA, and prepared in the lab (13, 17, 21 and 26ppth); and 5. Artificial San Joaquin River water diluted 75%, 50%, and 25% with artificial seawater to simulate mixing (13, 19, 24, and 30ppth). Survival, hatch, day to hatch and deformities were recorded. No significant difference was observed between artificial seawater and Monterey Bay aquarium brine and the EC50 values varied between 45-55ppth. These values suggest that under approprioate mixing conditions brine disposal into the open ocean would not be toxic to Japanese Medaka development. However, San Joaquin River water (primarily sulfate, sodium and calcium) decreased survival post hatch in comparison to artificial seawater and desalination brine suggesting that these ions may be more larval toxic.

  20. Bioconcentration, Metabolism and Excretion of Triclocarban in larval Qurt Medaka (Oryzias latipes)

    PubMed Central

    Schebb, Nils Helge; Flores, Ida; Kurobe, Tomofumi; Franze, Bastian; Ranganathan, Anupama; Hammock, Bruce D.; Teh, Swee

    2011-01-01

    The antimicrobial triclocarban (TCC) is frequently found in personal care products and commonly observed in surface waters and sediments. Due to its long environmental persistence TCC accumulates in sewage sludge. It also shows a high unintended biological activity as a potent inhibitor of the soluble epoxide hydrolase (sEH) and may be an endocrine disruptor. In this study, we investigated bioconcentration, metabolism and elimination of TCC in fish using Medaka (Oryzias latipes) as a model. Medaka larvae (7±1 days post hatching) were exposed to 63 nM (20 µg/L) TCC water for 24 hours. The LC-MS/MS analysis of water and tissues provided bioconcentration of TCC and its metabolites in fish body and rapid excretion into culture water. Results from tissue samples showed a tissue concentration of 34 µmol/kg and a log bioconcentration factor (BCF) of 2.86. These results are slightly lower than previous findings in snails and algae. A significant portion of the absorbed TCC was oxidatively metabolized by the fish to hydroxylated products. These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. The most abundant metabolite in fish tissue was the glucuronide of 2’-OH-TCC. Elimination of TCC after transferring the fish to fresh water was rapid, with a half-life of 1 hour. This study shows that larval medaka metabolize TCC similarly to mammals. The rapid rate of metabolism results in a lower bioconcentration than calculated from the n-octanol/water partition coefficient of TCC. PMID:21872556

  1. Disruption of circulation by ethanol promotes fetal alcohol spectrum disorder (FASD) in medaka (Oryzias latipes) embryogenesis.

    PubMed

    Hu, Yuhui; Khan, Ikhlas A; Dasmahapatra, Asok K

    2008-09-01

    Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features of fetal alcohol spectrum disorder (FASD) observed in human. The present experiment was designed to show that the disruption in circulation by ethanol during embryogenesis is a potential cause of FASD. Fertilized eggs were exposed to ethanol (0, 100 and/or 400 mM) for 24 or 48 h at various developmental stages (Iwamatsu stages 4-30) and were analyzed at 6 day post fertilization (dpf). It was observed that controls and the embryos exposed to 100 mM ethanol were in circulating state; however, a significant number of embryos of stages 4-24 exposed to 400 mM ethanol had disrupted circulation. Compared to controls, protein and RNA contents were significantly reduced in non-circulating embryos. Lipid peroxidation (LPO) analysis was made at 3, 6, 24, 48, 96 and 144 hour post fertilization (hpf). LPO was increased with the advancement of morphogenesis; however, ethanol or the circulation status had no effect. We further analyzed alcohol dehydrogenase (Adh 5 and adh8) and aldehyde dehydrogenase (Aldh9A and Aldh1A2) enzyme mRNAs in the embryos exposed to 400 mM ethanol for 24 h. A developmental stage-specific reduction in these enzyme mRNAs by ethanol was observed. We conclude that ethanol-induced disruption in circulation during embryogenesis is a potential cause of the development of FASD features in medaka.

  2. Water- and cryoprotectant-permeability of mature and immature oocytes in the medaka (Oryzias latipes).

    PubMed

    Valdez, Delgado M; Miyamoto, Akira; Hara, Takao; Seki, Shinsuke; Kasai, Magosaburo; Edashige, Keisuke

    2005-02-01

    The permeability of the plasma membrane plays a crucial role in the successful cryopreservation of oocytes/embryos. To identify a stage feasible for the cryopreservation of teleost oocytes, we investigated the permeability to water and various cryoprotectants of medaka (Oryzias latipes) oocytes at the germinal vesicle (GV) and metaphase II (MII) stages. In sucrose solutions, the volume changes were greater in GV oocytes than MII oocytes. Estimated values for osmotically inactive volume were 0.41 for GV oocytes and 0.74 for MII oocytes. Water-permeability (microm/min/atm) at 25 degrees C was higher in GV oocytes (0.13+/-0.01) than MII oocytes (0.06+/-0.01). The permeability of MII oocytes to various cryoprotectants (glycerol, propylene glycol, ethylene glycol, and DMSO) was quite low because the oocytes remained shrunken during 2 h of exposure in the cryoprotectant solutions at 25 degrees C. When the chorion of MII oocytes was removed, the volume change was not affected, except in DMSO solution, where dechorionated oocytes shrunk and then regained their volume slowly; the P(DMSO) value was estimated to be 0.14+/-0.01x10(-3) cm/min. On the other hand, the permeability of GV oocytes to cryoprotectants were markedly high, the P(s) values (x10(-3) cm/min) for propylene glycol, ethylene glycol, and DMSO being 2.21+/-0.29, 1.36+/-0.18, and 1.19+/-0.01, respectively. However, the permeability to glycerol was too low to be estimated, because GV oocytes remained shrunken after 2 h of exposure in glycerol solution. These results suggest that, during maturation, medaka oocytes become less permeable to water and to small neutral solutes, probably by acquiring resistance to hypotonic conditions before being spawned in fresh water. Since such changes would make it difficult to cryopreserve mature oocytes, immature oocytes would be more suitable for the cryopreservation of teleosts.

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

    PubMed

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

    2017-02-15

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

  4. Transcriptomic profiles of Japanese medaka (Oryzias latipes) in response to alkalinity stress.

    PubMed

    Yao, Z L; Wang, H; Chen, L; Zhou, K; Ying, C Q; Lai, Q F

    2012-08-13

    Oryzias latipes (Adrianichthyidae), known as Japanese medaka or Japanese killifish, is a small 2-4 cm long fish common in rice paddies in coastal Southeast Asia and is also a popular aquarium fish. It has been widely used as a research model because of its small size and because it is very easy to rear. Alkalinity stress is considered to be one of the major stressors on fish in saline-alkaline water. As very little is known about molecular genetic responses of aquatic organisms to alkalinity stress, we examined genome-wide gene expression profiles of Japanese medaka in response to carbonate alkalinity stress. Adult fish were exposed to freshwater and high carbonate alkaline water in the laboratory. We designed a microarray containing 26,429 genes for measuring gene expression change in the gills of the fish exposed to high carbonate alkalinity stress. Among these genes, 512 were up-regulated and 501 were down-regulated in the gills. These differentially expressed genes can be divided into gene groups using gene ontology, including biological processes, cellular components and molecular function. These gene groups are related to acid-base and ion regulation, cellular stress response, metabolism, immune response, and reproduction processes. Biological pathways including amino sugar and nucleotide sugar metabolism, porphyrin and chlorophyll metabolism, metabolism of xenobiotics by cytochrome P450, drug metabolism, aminoacyl-tRNA biosynthesis, glycine, serine and threonine metabolism, ascorbate and aldarate metabolism, pentose and glucuronate interconversions, glutathione metabolism, and fructose and mannose metabolism were significantly up-regulated. Alkalinity stress stimulates the energy and ion regulation pathways, and it also slows down the pathways related to the immune system and reproduction.

  5. Sequence analysis of choriogenin H gene of medaka (Oryzias latipes) and mRNA expression.

    PubMed

    Lee, Chulwoo; Jeon, Seong Hwan; Na, Jin Gyun; Park, Kwangsik

    2002-08-01

    Zona radiata proteins of medaka (Oryzias latipes) consist of two major subunit groups, ZI-1,2 and ZI-3. The precursor of ZI-1,2, which is a glycoprotein with a molecular weight of 74,000 to 76,000 Da, is called choriogenin H, and the precursor of ZI-3, with a molecular weight of 49,000 Da, is called choriogenin L. The precursor proteins are synthesized in the liver in response to estrogen in sexually mature female medaka. However, they are also induced in the male medaka when fish are exposed to estrogenic chemicals. Therefore, choriogenin is known as a possible sensitive biomarker for endocrine disruption in fish. In this study, the choriogenin H cDNA sequence was reanalyzed and the genomic DNA sequence was newly analyzed. This was done for the selection of proper reverse transcription-polymerase chain reaction (RT-PCR) primers to measure the choriogenin mRNA induction by estrogenic chemicals. In the results, the full cDNA sequence was found to be 2,109 bp long and the size of the open reading frame (ORF) was found to be a total of 1,998 bp encoding 666 predicted amino acids, which was found to be different from previously reported cDNA sequence of medaka choriogenin. In the choriogenin H cDNA, a repetitive domain and a nonrepetitive domain were shown. Regarding the repetitive domain, seven complete repeats of the 45 bp of 5'-ccc cag tac cca tca aag cct cag ccc cct cag aat cct cag gtc-3' encoding PQYPSKPQPPQNPQV were found. Medaka choriogenin H gene was found to possess seven exons and six introns, and the total length was 2,643 bp long. The seven repetitive nucleotide residues described above existed in exon 1, which was found to be 1,033 bp long. Based on the full sequence information, proper primers were synthesized for RT-PCR to detect choriogenin H mRNA induction in male and juvenile medaka by 17alpha-ethinylestradiol, and this type of measurement system was found to be effective as a simple tool for the screening of endocrine-disrupting chemicals.

  6. Testosterone content of developing eggs and sex reversal in the medaka (Oryzias latipes).

    PubMed

    Iwamatsu, Takashi; Kobayashi, Hirokuni; Sagegami, Reiko; Shuo, Takuya

    2006-01-01

    To understand the effect of testosterone on sex differentiation, the quantities of testosterone (T) and estradiol-17beta (E2) in developing eggs of medaka (Oryzias latipes) were measured by radioimmunoassay, and the influence on sex differentiation of treating embryos with exogenous androgens was also examined. Endogenous T of eggs dispersed into the environmental water at spawning, and precipitously declined to a minimum level during incubation for 2 days post-fertilization (dpf). It did not significantly increase during development. The E2 content of fertilized eggs increased when eggs were incubated in medium containing exogenous T at the concentrations of 100 and 500 ng/ml, but not in low concentrations of 10 ng/ml or less. The presence of 500 ng/ml 17alpha-methyltestosterone (MT) in the incubation medium also induced an increase in the E2 content of embryos. Exposure of embryos to exogenous 1 ng/ml T that corresponded with the level of T in eggs shortly after fertilization was enough to induce sex reversal of genotypic females to functional males. The co-existence of T and aromatase inhibitor in incubation medium inhibited not only the T-induced increase in the embryonic E2 content, but also the estrogenic effect of T in causing the paradoxical sex reversal from genotypic males to phenotypic females. However, treatment of embryos with the non-aromatizable androgen, 17alpha-methyldihydrotestosterone, induced no detectable increase in the E2 content of embryos, but still brought about sex reversal of genotypic males into females. This contradictory result suggests that the conversion of androgens to E2 may not always be the cause for induction of paradoxical sex reversal by T treatment. Consequently, these results on sex reversal induced by treatment of embryos with exogenous androgens suggest that endogenous T of developing medaka embryos may not act as the natural andro-inducer, and that genotypic sex can be modified by exogenous sex steroids at early

  7. 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.

  8. 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.

  9. Fertile and diploid nuclear transplants derived from embryonic cells of a small laboratory fish, medaka (Oryzias latipes)

    PubMed Central

    Wakamatsu, Yuko; Ju, Bensheng; Pristyaznhyuk, Inna; Niwa, Katsutoshi; Ladygina, Tatiana; Kinoshita, Masato; Araki, Kazuo; Ozato, Kenjiro

    2001-01-01

    Fertile and diploid nuclear transplants were successfully generated by using embryonic cells as donors in a small laboratory fish, medaka (Oryzias latipes). Embryonic cell nuclei from transgenic fish carrying the green fluorescent protein (GFP) gene were transplanted into unfertilized eggs enucleated by x-ray irradiation. In this study, 1 out of 588 eggs transplanted in the first experiment and 5 out of 298 eggs transplanted in the second experiment reached the adult stage. All of these nuclear transplants were fertile and diploid, and the natural and GFP markers of the donor nuclei were transmitted to the F1 and F2 offspring in a Mendelian fashion. This systematic study proves the feasibility of generating nuclear transplants by using embryonic cells from fish as donors, and it is supported by convincing evidence. PMID:11158596

  10. 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.

  11. Generation of a transgenic medaka (Oryzias latipes) strain for visualization of nuclear dynamics in early developmental stages.

    PubMed

    Inoue, Takanobu; Iida, Atsuo; Maegawa, Shingo; Sehara-Fujisawa, Atsuko; Kinoshita, Masato

    2016-12-01

    In this study, we verified nuclear transport activity of an artificial nuclear localization signal (aNLS) in medaka fish (Oryzias latipes). We generated a transgenic medaka strain expresses the aNLS tagged enhanced green fluorescent protein (EGFP) driven by a medaka beta-actin promoter. The aNLS-EGFP was accumulated in the nuclei of somatic tissues and yolk nuclei of oocytes, but undetectable in the spermatozoa. The fluorescent signal was observed from immediately after fertilization by a maternal contribution. Furthermore, male and female pronuclei were visualized in fertilized eggs, and nuclear dynamics of pronuclear fusion and subsequent cleavage were captured by time-lapse imaging. In contrast, SV40NLS exhibited no activity of nuclear transport in early embryos. In conclusion, the aNLS possesses a strong nuclear localization activity and is a useful probe for fluorescent observation of the pronuclei and nuclei in early developmental stage of medaka.

  12. Temperature-dependent growth rates and gene expression patterns of various medaka Oryzias latipes cell lines derived from different populations.

    PubMed

    Hirayama, Makoto; Mitani, Hiroshi; Watabe, Shugo

    2006-05-01

    Medaka Oryzias latipes has several geographically and genetically distinct populations. We examined temperature acclimation response in various medaka cell lines derived from different populations. Measurement of cell growth at various temperatures suggested that 15 degrees Celsius was the permissive growth temperature in all cell lines from the Northern Japanese and East Korean populations, but not in those from the Southern Japanese population and medaka-related species Oryzias celebensis, which inhabits a tropical zone. RT-PCR for 102 temperature-responsive genes, previously reported in other species, revealed that the accumulated mRNA level of a gene encoding HSP47 was lower at 25 degrees Celsius than at 33 degrees Celsius, and vice versa for 12 genes including IkappaBalpha and Rab-1c, in OLHNI-1 cell line from the Northern Japanese population. Further analysis by real-time PCR demonstrated that the accumulated mRNA levels of IkappaBalpha and Rab-1c in OLHNI-1 and OLSOK-e7 cell lines from the East Korean population were increased when the culture temperature was shifted from 33 to 15 degrees Celsius, but not in OLHdrR-e3 cell line from the Southern Japanese population. Since IkappaBalpha and Rab-1c are related to the NFkappaB cascade and endoplasmic reticulum-to-Golgi transport, respectively, it is inferred that immune responses and intracellular transport are possibly critical to temperature adaptation for medaka.

  13. Inheritance patterns of lateral dimorphism examined through breeding experiments in Tanganyikan cichlid (Julidochromis transcriptus) and Japanese Medaka (Oryzias latipes).

    PubMed

    Hata, Hiroki; Takahashi, Rieko; Ashiwa, Hiroshi; Awata, Satoshi; Takeyama, Tomohiro; Kohda, Masanori; Hori, Michio

    2012-01-01

    The asymmetry of mouth morphology, in which the mouth opens either leftward or rightward, is a unique example of antisymmetry that is widely found in fishes, such as Tanganyikan scale-eating cichlids, herbivorous cichlids, and the Japanese freshwater goby. This dimorphism is thought to be heritable in a Mendelian manner similar to that of the dominance of the lefty allele over righty, with homozygotes of lefty alleles being absent. This study aims to reveal whether this trait is inherited in the same Mendelian manner in fishes other than those examined to date, and whether the absence of the dominant homozygote is due to a lethal effect. We conducted F(1) and F(2) breeding experiments using the Tanganyikan cichlid Julidochromis transcriptus and Japanese medaka Oryzias latipes. For both J. transcriptus and O. latipes, the F(1) generations produced by incrossing lefty parents showed a lefty:righty ratio of 2:1, whereas incrosses of righties produced only righty offspring. Test crosses between lefty and righty produced a 1:1 ratio of lefty and righty offspring. These results are consistent with the inheritance model in which righty is homozygous for a recessive righty allele and lefty is heterozygous for dominant lefty and recessive righty alleles, in agreement with previous observations. The F(2) test cross also confirmed this pattern. Furthermore, no lethal effects on hatchability of O. latipes were detected, refuting the suggestion that the dominant homozygote is embryonic lethal. We conclude that mouth laterality is inherited in the same Mendelian manner in these two species, similar to that other fish species studied previously. However, the reason for absence of the dominant homozygote remains unclear.

  14. Multi-generational xenoestrogenic effects of Perfluoroalkyl acids (PFAAs) mixture on Oryzias latipes using a flow-through exposure system.

    PubMed

    Lee, Jin Wuk; Lee, Jae-Woo; Shin, Yu-Jin; Kim, Ji-Eun; Ryu, Tae-Kwon; Ryu, Jisung; Lee, Jaean; Kim, Pilje; Choi, Kyunghee; Park, Kyunghwa

    2017-02-01

    To elucidate the multi-generational estrogenic potential of Perfluoroalkyl acids (PFAAs) mixture, vitellogenin (VTG) expression, growth indices, histological alteration, fecundity, hatching rate, larval survival rate, and sex ratio of Japanese medaka (Oryzias latipes) were investigated by exposing the fish to a mixture of perfluorooctane sulfonate (PFOS), perfluroroctanoic acid (PFOA), perfluorobutane sulfonate (PFBS), and perfluorononanoic acid (PFNA) for three generations (238 days). Mixture composition is in the ratio of 1:1:1:1. In addition, whole body burden for each PFAA was analyzed. According to the results, concentrated levels of the PFAAs in both F1 and F2 generation O. latipes were ordered PFOS > PFNA > PFOA > PFBS at both low concentration (0.5 μg/L) and high concentration (5 μg/L), whereas a significant difference in whole body burden based on sex or generation was not detected. Significant induction of VTG expression in F2 and the decline of the gonad somatic index (GSI) in F1 were observed following PFAAs mixture exposure (p < 0.05, one-way ANOVA). Furthermore, suppression level of reproduction rate relative to the control increased as generation was transferred to the next in response to PFAAs mixture or 17 β-estradiol exposure, with the inhibition of hatchability observed in the F1 generation. The PFAA high concentration caused significant alteration of F1 generation sex ratio, suggesting the adverse effect of PFAA in population level (Chi-square test, P > 0.05). Overall, this study demonstrated that PFAA mixture could have the potential of multi-generational endocrine disruptors in O. latipes.

  15. Evaluation of Cryoprotectant and Cooling Rate for Sperm Cryopreservation in the Euryhaline Fish Medaka Oryzias latipes

    PubMed Central

    Yang, Huiping; Norris, Michelle; Winn, Richard; Tiersch, Terrence R.

    2017-01-01

    Medaka Oryzias latipes is a well-recognized biomedical fish model because of advantageous features such as small body size, transparency of embryos, and established techniques for gene knockout and modification. The goal of this study was to evaluate two critical factors, cryoprotectant and cooling rate, for sperm cryopreservation in 0.25-ml French straws. The objectives were to: 1) evaluate the acute toxicity of methanol, 2-methoxyethanol (ME), dimethyl sulfoxide (Me2SO), N, N- dimethylacetamide (DMA), N, N,-dimethyl formamide (DMF), and glycerol with concentrations of 5, 10, and 15% for 60 min of incubation at 4 °C; 2) evaluate cooling rates from 5 to 25 °C/min for freezing and their interaction with cryoprotectants, and 3) test fertility of thawed sperm cryopreserved with selected cryoprotectants and associated cooling rates. Evaluation of cryoprotectant toxicity showed that methanol and ME (5 and 10%) did not change the sperm motility after 30 min; Me2SO, DMA, and DMF (10 and 15%) and glycerol (5, 10 and 15%) significantly decreased the motility of sperm within 1 min after mixing. Based on these results, methanol and ME were selected as cryoprotectants (10%) to evaluate with different cooling rates (from 5 °C/min to 25 °C/min) and were compared to Me2SO and DMF (10%) (based on their use as cryoprotectants in previous publications). Post-thaw motility was affected by cryoprotectant, cooling rate, and their interaction (P ≤ 0.000). The highest post-thaw motility (50 ± 10%) was observed at a cooling rate of 10 °C/min with methanol as cryoprotectant. Comparable post-thaw motility (37 ± 12%) was obtained at a cooling rate of 15 °C/min with ME as cryoprotectant. With DMF, post-thaw motility at all cooling rates was ≤ 10% which was significantly lower than that of methanol and ME. With Me2SO, post-thaw motilities were less than 1% at all cooling rates, and significantly lower compared to the other three cryoprotectants (P ≤ 0.000). When sperm from

  16. Evaluation of cryoprotectant and cooling rate for sperm cryopreservation in the euryhaline fish medaka Oryzias latipes.

    PubMed

    Yang, Huiping; Norris, Michelle; Winn, Richard; Tiersch, Terrence R

    2010-10-01

    Medaka Oryzias latipes is a well-recognized biomedical fish model because of advantageous features such as small body size, transparency of embryos, and established techniques for gene knockout and modification. The goal of this study was to evaluate two critical factors, cryoprotectant and cooling rate, for sperm cryopreservation in 0.25-ml French straws. The objectives were to: (1) evaluate the acute toxicity of methanol, 2-methoxyethanol (ME), dimethyl sulfoxide (Me(2)SO), N,N-dimethylacetamide (DMA), N,N-dimethyl formamide (DMF), and glycerol with concentrations of 5%, 10%, and 15% for 60min of incubation at 4°C; (2) evaluate cooling rates from 5 to 25°C/min for freezing and their interaction with cryoprotectants, and (3) test fertility of thawed sperm cryopreserved with selected cryoprotectants and associated cooling rates. Evaluation of cryoprotectant toxicity showed that methanol and ME (5% and 10%) did not change the sperm motility after 30min; Me(2)SO, DMA, and DMF (10% and 15%) and glycerol (5%, 10% and 15%) significantly decreased the motility of sperm within 1min after mixing. Based on these results, methanol and ME were selected as cryoprotectants (10%) to evaluate with different cooling rates (from 5 to 25°C/min) and were compared to Me(2)SO and DMF (10%) (based on their use as cryoprotectants in previous publications). Post-thaw motility was affected by cryoprotectant, cooling rate, and their interaction (P⩽0.000). The highest post-thaw motility (50±10%) was observed at a cooling rate of 10°C/min with methanol as cryoprotectant. Comparable post-thaw motility (37±12%) was obtained at a cooling rate of 15°C/min with ME as cryoprotectant. With DMF, post-thaw motility at all cooling rates was ⩽10% which was significantly lower than that of methanol and ME. With Me(2)SO, post-thaw motilities were less than 1% at all cooling rates, and significantly lower compared to the other three cryoprotectants (P⩽0.000). When sperm from individual males

  17. 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.

  18. Non-stressful temperature effect on oxidative balance and life history traits in adult fish (Oryzias latipes).

    PubMed

    Hemmer-Brepson, C; Replumaz, L; Romestaing, C; Voituron, Y; Daufresne, M

    2014-01-15

    Temperature is well known to affect many biological and ecological traits, especially in ectotherms. From a physiological point of view, temperature is also positively correlated to metabolism and is often associated with an increase in reactive oxygen species (ROS) production. It has recently been suggested that ROS play a role in lifespan and resource allocation. However, only a few authors have attempted to explore the relationships between temperature, resource allocation and oxidative balance in ectotherms. Here, we measured the effect of temperature on growth, reproductive effort, offspring quantity and quality, hatching and survival rates, and the associated proximal costs, which were evaluated through the quantification of oxidative balance elements. We reared adult fish (Oryzias latipes) at two non-stressful temperatures (20 and 30°C) during a relatively long period (4 months, approximately the entire adult life). The results show a trade-off between reproduction and maintenance because investment toward growth could be neglected at the adult stage (confirmed by our results). Intriguingly, ROS-dependent damages did not differ between the two groups, probably because of the higher rate of activation of the antioxidant enzyme superoxide dismutase for warm-acclimated fish. The allocation toward antioxidant defences is associated with an earlier reproduction and a lower quality of offspring. These interesting results bring new perspectives in terms of the prediction of the impact of global warming on biota through the use of ecological theories based on oxidative balance and metabolism.

  19. 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.

  20. Effects of Acrobat MZ and Tattoo C on Japanese medaka (Oryzias latipes) development and adult male behavior.

    PubMed

    Teather, K; Harris, M; Boswell, J; Gray, M

    2001-02-01

    Exposure of Japanese medaka (Oryzias latipes) embryos and adult males to sublethal concentrations of two commonly used fungicides, Acrobat MZ and Tattoo C, had varying effects on development and adult male behavior. During embryolarval assays, medaka exposed to Acrobat exhibited decreased heart rates throughout embryonic development and were smaller at hatching than controls. Differences in hatching size were not apparent with Tattoo although some decrease in heart rate was observed at higher concentrations. Tail lesions and abnormal spinal development was a problem common to embryos exposed to Acrobat. Neither time to hatch nor early growth was affected by exposure to either fungicide. Adult males that had been exposed to high concentrations of Acrobat or Tattoo over a 28-day period were less likely to approach females during behavioral trials. The absence of other behavioral effects, particularly those related to reproductive performance, may have been due to females being sexually unreceptive during behavioral trials. No other behavioral modifications were apparent for adult males exposed to either fungicide. Information about developmental and behavioral responses to sublethal concentrations of pesticides is important for establishing environmental guidelines concerning their use.

  1. Apoptosis and morphological alterations after UVA irradiation in red blood cells of p53 deficient Japanese medaka (Oryzias latipes).

    PubMed

    Sayed, Alla El-Din Hamid; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-08-01

    Morphological alterations in red blood cells were described as hematological bioindicators of UVA exposure to investigate the sensitivity to UVA in wild type Japanese medaka (Oryzias latipes) and a p53 deficient mutant. The fewer abnormal red blood cells were observed in the p53 mutant fish under the control conditions. After exposure to different doses of UVA radiation (15min, 30min and 60min/day for 3days), cellular and nuclear alterations in red blood cells were analyzed in the UVA exposed fish compared with non-exposed controls and those alterations included acanthocytes, cell membrane lysis, swollen cells, teardrop-like cell, hemolyzed cells and sickle cells. Those alterations were increased after the UVA exposure both in wild type and the p53 deficient fish. Moreover, apoptosis analyzed by acridine orange assay showed increased number of apoptosis in red blood cells at the higher UVA exposure dose. No micronuclei but nuclear abnormalities as eccentric nucleus, nuclear budding, deformed nucleus, and bilobed nucleus were observed in each group. These results suggested that UVA exposure induced both p53 dependent and independent apoptosis and morphological alterations in red blood cells but less sensitive to UVA than Wild type in medaka fish.

  2. An Approach to Elucidate NBS1 Function in DNA Repair Using Frequent Nonsynonymous Polymorphism in Wild Medaka (Oryzias latipes) Populations.

    PubMed

    Igarashi, Kento; Kobayashi, Junya; Katsumura, Takafumi; Urushihara, Yusuke; Hida, Kyohei; Watanabe-Asaka, Tomomi; Oota, Hiroki; Oda, Shoji; Mitani, Hiroshi

    2017-01-01

    Nbs1 is one of the genes responsible for Nijmegen breakage syndrome, which is marked with high radiosensitivity. In human NBS1 (hNBS1), Q185E polymorphism is known as the factor to cancer risks, although its DSB repair defect has not been addressed. Here we investigated the genetic variations in medaka (Oryzias latipes) wild populations, and found 40 nonsynonymous single nucleotide polymorphisms (SNPs) in medaka nbs1 (olnbs1) gene within 5 inbred strains. A mutation to histidine in Q170 residue in olNbs1, which corresponds to Q185 residue of hNBS1, was widely distributed in the closed colonies derived from the eastern Korean population of medaka. Overexpression of H170 type olNbs1 in medaka cultured cell lines resulted in the increased accumulation of olNbs1 at laser-induced DSB sites. Autophosphorylation of DNA-dependent protein kinase at T2609 was suppressed after the γ-ray irradiation, which was followed by prolonged formation of γ-H2AX foci and delayed DSB repair. These findings suggested that the nonsynonymous SNP (Q170H) in olnbs1, which induced DSB repair defects, is specifically distributed in the eastern Korean population of medaka. Furthermore, examination using the variation within wild populations might provide a novel method to characterize a driving force to spread the disease risk alleles.

  3. 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.

  4. Diploidized eggs reprogram adult somatic cell nuclei to pluripotency in nuclear transfer in medaka fish (Oryzias latipes).

    PubMed

    Bubenshchikova, Ekaterina; Kaftanovskaya, Elena; Motosugi, Nami; Fujimoto, Takafumi; Arai, Katsutoshi; Kinoshita, Masato; Hashimoto, Hisashi; Ozato, Kenjiro; Wakamatsu, Yuko

    2007-12-01

    Reprogramming of adult somatic cell nuclei to pluripotency has been unsuccessful in non-mammalian animals, primarily because of chromosomal aberrations in nuclear transplants, which are considered to be caused by asynchrony between the cell cycles of the recipient egg and donor nucleus. In order to normalize the chromosomal status, we used diploidized eggs by retention of second polar body release, instead of enucleated eggs, as recipients in nuclear transfer of primary culture cells from the caudal fin of adult green fluorescent protein gene (GFP) transgenic medaka fish (Oryzias latipes). We found that 2.7% of the reconstructed embryos grew into adults that expressed GFP in various tissues in the same pattern as in the donor fish. Moreover, these fish were diploid, fertile and capable of passing the marker gene to the next generation in Mendelian fashion. We hesitate to call these fish 'clones' because we used non-enucleated eggs as recipients; in effect, they may be chimeras consisting of cells derived from diploid recipient nuclei and donor nuclei. In either case, fish adult somatic cell nuclei were reprogrammed to pluripotency and differentiated into a variety of cell types including germ cells via the use of diploidized recipient eggs.

  5. The Effects of Rearing Density, Salt Concentration, and Incubation Temperature on Japanese Medaka (Oryzias latipes) Embryo Development

    PubMed Central

    Rosemore, Bethany J.

    2012-01-01

    Abstract Environmental stressors are often present when an aquatic species, such as the Japanese medaka (Oryzias latipes) fish, are developing. This study examined the effects of some of these environmental stressors (variation in rearing density, salinity, and incubation temperature) on medaka embryo development. The hypotheses are if rearing density is increased, then hatching success will also be improved, while having no effect on embryo development; if the salt concentration is increased to 20 parts per thousand (ppt), then the rate of development will also be increased; if temperature is increased to 32°C, then the rate of development will also be increased. To determine the effects of variations in rearing density (1, 2, 3, and 4 eggs per well), the time of hatch was observed and noted. When testing variations in temperature (24°, 28°, and 32°C) and salinity (0.3, 10, 15, and 20 ppt), the onset of heartbeat and onset of retina pigmentation were observed. The original hypotheses were not all supported: as rearing density increased, success of hatch decreased; as salinity increased, only the rate of development for heartbeat increased; as temperature increased, the rate of development for both onset of the heartbeat and retina pigmentation also increased. PMID:23244689

  6. Effects of triclosan on the early life stages and reproduction of medaka Oryzias latipes and induction of hepatic vitellogenin.

    PubMed

    Ishibashi, Hiroshi; Matsumura, Naomi; Hirano, Masashi; Matsuoka, Munekazu; Shiratsuchi, Hideki; Ishibashi, Yasuhiro; Takao, Yuji; Arizono, Koji

    2004-04-14

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. In this study, the effects of TCS on the early life stages and reproduction of medaka (Oryzias latipes) were investigated. The 96-h median lethal concentration value of TCS for 24-h-old larvae was 602 microg/l. The hatchability and time to hatching in fertilized eggs exposed to 313 microg/l TCS for 14 days were significantly decreased and delayed, respectively. An assessment of the effects of a TCS 21-day exposure period on the reproduction of paired medaka showed no significant differences in the number of eggs produced and fertility among the control and 20, 100 and 200 microg/l TCS treatment groups. However, concentrations of hepatic vitellogenin were increased significantly in males treated with TCS at 20 and 100 microg/l. In the F(1) generations, although the hatching of embryos in the 20 microg/l treatment showed adverse effects, there was no dose-response relationship between hatchability and TCS treatment levels. These results suggest that TCS has high toxicity on the early life stages of medaka, and that the metabolite of TCS may be a weak estrogenic compound with the potential to induce vitellogenin in male medaka but with no adverse effect on reproductive success and offspring.

  7. Protection against nonylphenol-induced cell death by DJ-1 in cultured Japanese medaka (Oryzias latipes) cells.

    PubMed

    Li, Hong Mei; Taira, Takahiro; Maita, Chinatsu; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M M

    2006-12-07

    The Japanese medaka (Oryzias latipes) has been used to investigate diverse aspects of toxicology, genetics and developmental biology and to monitor biological changes caused by endocrine disruptors. In this study, we analyzed a medaka homolog of human DJ-1 (meDJ-1) in cultured medaka cells into which nonylphenol (NP) was added. Like human DJ-1, meDJ-1 was found to be oxidized by treatment with H(2)O(2) and its pI was shifted to acidic points. NP was found to induce cell death with kinetics similar to that of H(2)O(2) in cultured medaka OLHE-13 cells. After OLHE-13 cells had been treated with sub-lethal concentrations of H(2)O(2) and NP, production of reactive oxygen species and oxidation of meDJ-1 were observed. meDJ-1 knockdown by short interfering RNA rendered OLHE-13 cells susceptible to H(2)O(2) and NP-induced cell death, suggesting a protective role of DJ-1 against oxidative stress-induced cell death in medaka cells. These results suggest that meDJ-1 is a suitable biomarker for oxidative stress reactions in medaka.

  8. An Approach to Elucidate NBS1 Function in DNA Repair Using Frequent Nonsynonymous Polymorphism in Wild Medaka (Oryzias latipes) Populations

    PubMed Central

    Igarashi, Kento; Kobayashi, Junya; Katsumura, Takafumi; Urushihara, Yusuke; Hida, Kyohei; Watanabe-Asaka, Tomomi; Oota, Hiroki; Oda, Shoji

    2017-01-01

    Nbs1 is one of the genes responsible for Nijmegen breakage syndrome, which is marked with high radiosensitivity. In human NBS1 (hNBS1), Q185E polymorphism is known as the factor to cancer risks, although its DSB repair defect has not been addressed. Here we investigated the genetic variations in medaka (Oryzias latipes) wild populations, and found 40 nonsynonymous single nucleotide polymorphisms (SNPs) in medaka nbs1 (olnbs1) gene within 5 inbred strains. A mutation to histidine in Q170 residue in olNbs1, which corresponds to Q185 residue of hNBS1, was widely distributed in the closed colonies derived from the eastern Korean population of medaka. Overexpression of H170 type olNbs1 in medaka cultured cell lines resulted in the increased accumulation of olNbs1 at laser-induced DSB sites. Autophosphorylation of DNA-dependent protein kinase at T2609 was suppressed after the γ-ray irradiation, which was followed by prolonged formation of γ-H2AX foci and delayed DSB repair. These findings suggested that the nonsynonymous SNP (Q170H) in olnbs1, which induced DSB repair defects, is specifically distributed in the eastern Korean population of medaka. Furthermore, examination using the variation within wild populations might provide a novel method to characterize a driving force to spread the disease risk alleles. PMID:28107384

  9. 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.

  10. The interaction effects of binary mixtures of benzene and toluene on the developing heart of medaka (Oryzias latipes).

    PubMed

    Teuschler, Linda K; Gennings, Chris; Hartley, William R; Carter, Hans; Thiyagarajah, Arunthavarani; Schoeny, Rita; Cubbison, Chris

    2005-03-01

    The United States Environmental Protection Agency (USEPA) has pursued the estimation of risk of adverse health effects from exposure to chemical mixtures since the early 1980s. Methods used to calculate risk estimates of mixtures were often based on single chemical information that required assumptions of dose-addition or response-addition and did not consider possible changes in response due to interaction effects among chemicals. Full factorial designs for laboratory studies can produce interactions information, but these are expensive to perform and may not provide the information needed to evaluate specific environmentally relevant mixtures. In this research, groups of Japanese medaka (Oryzias latipes) embryos were exposed to binary mixtures of benzene and toluene as well as to each of these chemicals alone. Endpoint specific dose-response models were built for the hydrocarbon mixture under an assumption of dose-additivity, using the single chemical dose-response information on benzene and toluene. The endpoints included heart rate, heart rate progression, and lethality. Results included a synergistic response for heart rate at 72 h of development, and either additivity or antagonism for all other endpoints at 96 h of development. This work uses an established statistical method to evaluate the toxicity of an environmentally relevant mixture to ascertain whether interaction effects are occurring, thus providing additional information on toxicity.

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

    PubMed

    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

    2014-08-01

    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.

  12. The acetylcholinesterase (AChE) inhibition analysis of medaka (Oryzias latipes) in the exposure of three insecticides.

    PubMed

    Zhu, Jianping; Huan, Cheng; Si, Guiyun; Yang, Haitang; Yin, Li; Ren, Qing; Ren, Baixiang; Fu, Rongshu; Miao, Mingsheng; Ren, Zongming

    2015-03-01

    The continuous effects on Acetylcholinesterase (AChE) activity of medaka (Oryzias latipes) caused by dichlorvos, methomyl and deltamethrin in vivo were investigated, and the trends of AChE activity inhibition due to the influence of these insecticides were discussed. The LC50-24h of dichlorvos, methomyl and deltamethrin on medaka were 2.3 mg/L, 0.2 mg/L, and 2.9×10(-3) mg/L respectively. The result suggested that at the beginning of the exposure, the AChE activity might increase, and the AChE activity in dead individuals was obviously lower than the live individuals. Though the de novo synthesis of AChE in medaka might help the AChE activity recover, the trends during the exposure in different treatments were downward, and it showed both exposure time and concentration dependent. Meanwhile, higher temperature might cause the AChE inhibition earlier due to the higher metabolic rate. Therefore, as a specific biomarker for organophosphate, carbamate pesticides and pyrethroids, the degree of the AChE inhibition with in vivo conditions is a good tool in continuous monitoring of insecticides, which may induce the nerve conduction disorders.

  13. Multiple cocaine- and amphetamine-regulated transcript (CART) genes in medaka, Oryzias latipes: cloning, tissue distribution and effect of starvation.

    PubMed

    Murashita, Koji; Kurokawa, Tadahide

    2011-02-01

    The neuropeptide cocaine- and amphetamine-regulated transcript (CART) is important in the regulation of food intake in mammals and fish. The tissue distributions of six CART cDNAs (cart ch3, ch4, ch6, ch9, ch11, and ch22) from medaka, Oryzias latipes, were cloned and the effect of starvation on their expression was examined. As in other species, medaka cart ch3, ch4, ch6, ch9, and ch22 consisted of three exons, while medaka cart ch11 contained four. The six cysteine residues at the C-terminal end of the CART motif and three-dimensional structure were well conserved in all medaka CART peptides. Tissue distribution analysis revealed that cart ch3, ch4, ch6, ch11, and ch22 were primarily expressed in the brain, but that the highest rates of cart ch9 expression occurred in the skin, suggesting different functions among the homologous genes. Although CART ch3 mRNA levels decreased in response to 17 days starvation, these levels were restored by re-feeding. However, the finding that the five other CART mRNAs did not respond to starvation suggests that only CART ch3 has an anorexigenic function in medaka. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Comparative embryotoxicity of pulp mill extracts in rainbow trout (Oncorhynchus mykiss), American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes).

    PubMed

    Orrego, Rodrigo; Guchardi, John; Beyger, Lindsay; Krause, Rachelle; Holdway, Douglas

    2011-08-01

    This study evaluated the effects of Chilean pulp mill effluent extracts (untreated, primary and secondary treated pulp mill effluents), along with steroid standards (testosterone and 17β-estradiol) and a wood extractive standard (beta-sitosterol) on developing post-fertilized fish embryos. Our study included a cold freshwater species, rainbow trout (Oncorhynchus mykiss), and two warm freshwater species American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes). Embryotoxicity results included delay in time to hatch and decreased hatchability but no significant egg and larvae mortality was observed in the pulp mill extract exposed embryos. By contrast, significant early hatching and increased hatchability were observed in beta-sitosterol exposed embryos, along with high mortality of testosterone exposed embryos across species. Teratogenic responses were observed in medaka embryos in all treatments. Abnormalities were detected starting at development stages 19-20 (2-4 somite stages) and included optical deformities (micro-opthalmia, 1 or 2 eyes) and lack of development of brains and hearts. Additionally, phenotypic sex identification of surviving offspring found female-biased sex-ratios in all treatments except testosterone across species. Overall, our study indicated that Chilean pulp and paper mill extractives caused embryotoxicity (post-fertilized embryos) across species and irrespective of the effluent treatment. The effects were mainly associated with delayed time to hatch, decreased hatchability, and species-specific teratogenesis.

  15. Acute Exposure to 17α-Ethinylestradiol Alters Aggressive Behavior of Mosquitofish (Gambusia affinis) Toward Japanese Medaka (Oryzias latipes).

    PubMed

    Dang, Hieu M; Inagaki, Yoshihiko; Yamauchi, Yuta; Kurihara, Takaaki; Vo, Cong H; Sakakibara, Yutaka

    2017-02-03

    Behavior of the mosquitofish (Gambusia affinis) toward the Japanese medaka (Oryzias latipes) was tested under exposure to environmental 17α-ethinylestradiol (EE2), a synthetic derivative of natural estrogen, estradiol. The mosquitofish were exposed to EE2 at different concentrations-0, 0.5, 5.0, and 50.0 ng/L-for 2 days, before their behavioral changes toward the medaka were observed. Results indicate that female mosquitofish became more aggressive at the high level of EE2 (50 ng/L), in terms of how persistently they attempted to approach the medaka. The males showed increased aggressive behavior toward the medaka, by significantly increasing the number and persistence of approach attempts at the low (0.5 and 5 ng/L) levels of EE2. At the highest EE2 concentration (50 ng/L), however, the number of attempts decreased, while the persistence increased in the males showing the same pattern as in the females. All behavioral changes were reversed once EE2 was removed from the environment.

  16. 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

  17. [Expression of elongation factor-1 alpha-A and beta-actin promoters in embryos of transgenic Medaka (Oryzias latipes)].

    PubMed

    Long, Hua

    2003-06-01

    Two expression vectors with the promoter of either Medaka (Oryzias latipes) elongation factor gene or beta-actin gene were constructed based on pBluescript SK+. Both of them are linked with green-fluorescent protein (GFP) gene. And they are named as pB-EF and pB-BA, respectively. The microinjection experiments were conducted with fertilized Medaka eggs at one-cell stage. The expression of two vectors, pB-EF and pB-BA, was observed under stereo-fluorescence microscope. The detection results showed that both EF-1 alpha-A promoter and beta-actin promoter are strong. In the process of embryo development, the activity of beta-actin promoter became stronger while that of EF-1 alpha-A promoter weaker gradually. beta-actin promoter was but EF-1 alpha-A promoter distributed throughout fish body uniformly. The expression rate of two vectors, pB-EF and pB-BA, are 8.23% and 6.10%, respectively.

  18. 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.

  19. 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...

  20. 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...

  1. 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

    USDA-ARS?s Scientific Manuscript database

    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-...

  2. 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. 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.

  3. Mechanisms of Selenomethionine Developmental Toxicity and the Impacts of Combined Hypersaline Conditions on Japanese Medaka (Oryzias latipes)

    PubMed Central

    2015-01-01

    Selenium (Se) is an essential micronutrient that can cause embryotoxicty at levels 7–30 times above essential concentrations. Exposure to hypersaline conditions and 50 μM selenomethionine (SeMet) decreased embryo hatch and depleted glutathione in Japanese medaka embryos without affecting Se accumulation. To better understand the impacts of nonchemical stressors on developmental toxicity of Se in fish, several adverse outcome pathways were evaluated in the Japanese medaka (Oryzias latipes). We treated medaka embryos at 12 h post fertilization with 50 μM SeMet for 12 hours in freshwater or in 13 ppth hypersalinity and evaluated the contributions of oxidative stress, the unfolded protein response and apoptosis to reduced hatch. Exposure to SeMet and hypersalinity decreased embryo hatch to 3.7% ± 1.95, and induced teratogenesis in 100% ± 0 of hatched embryos. In contrast, treatments of freshwater, saltwater, and SeMet in freshwater resulted in 89.8% ± 3.91–86.7% ± 3.87 hatch, and no significant increase in deformities. We found no significant differences in lipid peroxidation, indicating that oxidative stress may not be responsible for the observed toxicity in embryos at this time point (24 h). Although significant changes in apoptosis were not observed, we witnessed up to 100 fold increases in transcripts of the endoplasmic reticulum (ER) chaperone, immunoglobulin binding protein (BiP) and trends toward increasing downstream signals, activating transcription factor 4 (ATF4) and ATF6 indicating potential contributions of the unfolded protein response to the effects of SeMet and hypersaline conditions. These data indicate that multiple adverse outcome pathways may be responsible for the developmental toxicity of Se and salinity, and these pathways may be time dependent. PMID:24856650

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

    PubMed

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

    2003-01-01

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

  5. 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.

  6. Contaminated sediments from tributaries of the Great Lakes: Chemical characterization and carcinogenic effects in medaka (Oryzias latipes)

    USGS Publications Warehouse

    Besser, John M.; Schmitt, Christopher J.; Harshbarger, John C.; Peterman, Paul H.; Lebo, Jon A.

    1991-01-01

    Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with organic solvents to produce a crude extract, which was separated on alumina into two fractions: predominantly polycyclic aromatic hydrocarbons; and predominantly nitrogencontaining polycyclic aromatic compounds. Crude extracts were redissolved in acetone and analyzed by gas chromatography and gas chromatography-mass spectrometry. The acetone-redissolved crude extracts from the four industrialized sites contained 5.6–313.3 μg total polycyclic aromatic compounds/g sediment and 3.0–36.4 μg other compounds/g sediment. In addition to the typical EPA priority pollutants, a substantial amount (228.7 μg/g sediment) of alkyl-polycyclic-aromatic compounds was detected in sediments from one of the industrialized sites. Extracts from the reference site contained 1.55 μg total polycyclic aromatic compounds/ g sediment. Medaka (Oryzias latipes) were exposed to multiple pulse doses of acetone-redissolved extracts and fractions. Medaka were also exposed to a known carcinogen, methylazoxymethanol acetate, to verify that chemicals produced tumors in the test fish. Acetone-redissolved extracts and fractions from contaminated sediments were toxic to medaka. Fin erosion and non-neoplastic liver abnormalities were more prevalent in medaka after exposure to acetoneredissolved extracts and fractions from contaminated sediments. Neoplasms previously associated with chemical exposure in wild fishes were induced in medaka exposed to acetone-redissolved extracts and fractions from two of the contaminated sites, but not from the reference site or controls. These findings further support the hypothesis that chemical contaminants in sediments are involved in epizootics of neoplasms in wild fishes at contaminated sites.

  7. 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.

  8. 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.

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

    PubMed

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

    2017-08-01

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

  10. 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

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

    PubMed Central

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

    2011-01-01

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

  12. 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.

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

    PubMed

    Madsen, Steffen S; Bujak, Joanna; Tipsmark, Christian K

    2014-09-01

    We investigated the salinity-dependent expression dynamics of seven aquaporin paralogs (aqp1a, aqp3a, aqp7, aqp8ab, aqp10a, aqp10b and aqp11a) in several tissues of euryhaline Japanese medaka (Oryzias latipes). All paralogs except aqp7 and aqp10a had a broad tissue distribution, and several were affected by salinity in both osmoregulatory and non-osmoregulatory tissues. In the intestine, aqp1a, aqp7, aqp8ab and aqp10a decreased upon seawater (SW) acclimation in both long-term acclimated fish and during 1-3 days of the transition period. In the gill, aqp3a was lower and aqp10a higher in SW than in freshwater (FW). In the kidney no aqps were affected by salinity. In the skin, aqp1a and aqp3a were lower in SW than in FW. In the liver, aqp8ab and aqp10a were lower in SW than in FW. Furthermore, six Na(+),K(+)-ATPase α-subunit isoform transcripts were analysed in the intestine but none showed a consistent response to salinity, suggesting that water transport is not regulated at this level. In contrast, mRNA of the Na(+),K(+),2Cl(-)-cotransporter type-2 strongly increased in the intestine in SW compared with FW fish. Using custom-made antibodies, Aqp1a, Aqp8ab and Aqp10a were localized in the apical region of enterocytes of FW fish. Apical staining intensity strongly decreased, vanished or moved to subapical regions, when fish were acclimated to SW, supporting the lower mRNA expression in SW. Western blots confirmed the decrease in Aqp1a and Aqp10a in SW. The strong decrease in aquaporin expression in the intestine of SW fish is surprising, and challenges the paradigm for transepithelial intestinal water absorption in SW fishes.

  14. Cytosolic free calcium-ion concentration in cleaving embryonic cells of Oryzias latipes measured with calcium-selective microelectrodes

    PubMed Central

    1985-01-01

    Calcium-selective microelectrodes were used to measure the free calcium- ion concentration ([Ca2+]i) in early-cleaving embryonic cells of the golden medaka, Oryzias latipes, a fresh water teleost fish. Embryos could be dechorionated as early as the four-cell stage using a three- step technique consisting of removal of some yolk to enlarge the perivitelline space, partial digestion of the chorion with pancreatin, and removal of the weakened chorion with forceps. Dechorionated embryos underwent cleavage at a normal rate. Intracellular cytosolic [Ca2+]i was monitored by impaling blastomeres first with a microelectrode filled with 5 M potassium acetate to measure membrane potential, and a few minutes later with a calcium-selective microelectrode. During nine rounds of cytokinesis from a total of six different embryos, cytosolic [Ca2+]i remained constant (with apparently random fluctuations of less than +/- 0.1 microM). During two successive cleavages in one embryo, however, [Ca2+]i rose transiently fourfold above the original resting level to 1.32 and 1.20 microM in synchrony with each period of cytokinesis and returned after each rise to submicromolar levels. Because a calcium-selective microelectrode can detect [Ca2+]i changes only in the immediate vicinity of its 2-microns tip, we interpreted these data to suggest that, although [Ca2+]i in most areas of the cytosol remains between 0.01 and 0.40 microM (mean of 0.14 microM), there may be small regions of the cell in which [Ca2+]i undergoes a substantial increase at the time of cleavage. Evidence also is presented to suggest that the membrane potential in these blastomeres undergoes a slow net hyperpolarization during early cleavage stages. PMID:3972904

  15. Developmental expression and regulation of flavin-containing monooxygenase by the unfolded protein response in Japanese medaka (Oryzias latipes).

    PubMed

    Kupsco, Allison; Schlenk, Daniel

    2017-01-01

    Flavin-containing monooxygenases (FMOs) play a key role in xenobiotic metabolism, are regulated by environmental conditions, and are differentially regulated during mammalian development. Japanese medaka (Oryzias latipes) are a common model organism for toxicological studies. The goal of the current research was to characterize developmental expression and regulation of FMOs in Japanese medaka embryos to better understand the role of FMOs in this model species. Five putative medaka fmos were characterized from the medaka genome through the National Center for Biotechnology Information (NCBI) database by protein motifs and alignments, then identified as fmo4, fmo5A, fmo5B, fmo5C and fmo5D for the current study. Fmo gene expression was analyzed at 1dpf, 3dpf, 6dpf and 9dpf and distinct developmental patterns of expression were observed. Fmo4 and fmo5D increased 3-fold during mid organogenesis (6dpf), while fmo5B and fmo5C decreased significantly in early organogenesis (3dpf) and fmo5A was unaltered. Promoter analysis was performed for transcription factor binding sites and indicated regulation by developmental factors and a role for the unfolded protein response in fmo modulation. Fmo regulation by the UPR was assessed with treatments of 1μg/ml, 2μg/ml, and 4μg/ml Tunicamycin (Tm), and 2mM and 4mM dithiothreitol (DTT), well-known inducers of endoplasmic reticulum stress, for 24h from 5-6dpf. High concentrations to Tm induced fmo4 and fmo5A up to two-fold, while DTT significantly decreased expression of fmo5A, fmo5B, and fmo5C. Results suggest that medaka fmos are variably regulated by the UPR during organogenesis with variable developmental expression, and suggesting potential stage-dependent activation or detoxification of xenobiotics. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 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

  17. Evaluation of the 5α-reductase inhibitor finasteride on reproduction and gonadal development in medaka, Oryzias latipes.

    PubMed

    Lee, Michael R; Loux-Turner, Jana R; Oliveira, Kenneth

    2015-05-15

    5-α reductase (5αR) inhibitors have an anti-androgenic effect in mammals because they inhibit the conversion of testosterone to the potent androgen, dihydrotestosterone. Finasteride is a type-2 5αR inhibitor that is used as a human pharmaceutical for the treatment of prostate cancer, benign prostate hyperplasia and male pattern baldness. This study evaluated the impacts of finasteride (50, 500 and 5000μg/L) on the development and reproduction of medaka (Oryzias latipes) exposed continuously over multiple generations (F0, F1 and F2). The exposure was initiated with reproductively mature fish (F0 generation) and continued until the hatching of the F2 generation. There were no significant effects on survival, fecundity or fertility in the F0 (50, 500, 5000μg/L) and F1 (50, 500μg/L) generations. The F1 generation exposed to 5000μg/L exhibited significant mortality. Histopathology of the gonads demonstrated that medaka and pre-clinical species respond similarly to finasteride exposure. Intersex condition and maldeveloped gonads were observed in F0 generation males exposed to 5000μg/L and F1 generation males exposed to 500μg/L. F1 generation males exposed to 500μg/L displayed reduced gonadosomatic index with an increased incidence of testicular degeneration. Males in both generations exhibited an increased incidence of Leydig cell hyperplasia at concentrations ⩾500μg/L. F0 generation females exposed to 5000μg/L exhibited increased gonadosomatic index. An increased prevalence of accelerated post-ovulatory follicle involution was observed in females at concentrations ⩾500μg/L in both generations. The gonadal changes induced by finasteride support the idea that 5-α reductase inhibition impacts androgen signaling in fish. Results from this study are discussed in the context of differential expression of the androgen receptor between species of fish. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Use of V agents and V-analogue compounds to probe the active site of atypical butyrylcholinesterase from Oryzias latipes.

    PubMed

    Kirkpatrick, Melanie G; diTargiani, Robert C; Sweeney, Richard E; Otto, Tamara C

    2016-11-25

    The atypical butyrylcholinesterase (aBuChE) from Oryzias latipes shares approximately 65% sequence similarity to both acetylcholinesterase and butyrylcholinesterase and was studied for its capacity to spontaneously reactivate following inhibition by organophosphorus nerve agents. Like other cholinesterases, aBuChE was inhibited by all G- and V-type nerve agents. Interestingly, aBuChE was able to undergo spontaneous reactivation after inhibition with VR (t1/2 = 5.5 ± 0.2 h). Mass spectrometry of aBuChE after VR inhibition confirmed the presence of a covalently bound adduct of the size expected for non-aged VR on the peptide containing the active site serine. To understand the effect of substrate volume on rates of reactivation, the capacity of aBuChE to bind and spontaneously reactivate after inhibition with five V-agent analogues was examined. No appreciable reactivation was detected for enzyme inhibited by V2 (VX with O-isopropyl on retained group), V4 (VX with N-diethyl leaving group termination), or V5 (VX with N-dimethyl leaving group termination). Minimal reactivation was detected with V1 (VX with O-propyl on retained group). Conversely, spontaneous reactivation was observed when aBuChE was inhibited by V3 (VX with O-isobutyl on retained group; t1/2 = 6.3 ± 0.4 h). The data suggest that the ability of aBuChE to spontaneously reactivate after inhibition by V-agent analogues is related to the structure of the retained group. These results provide structural information that may shed light on the design of improved small molecule reactivators of nerve agent-inhibited acetylcholinesterase or butyrylcholinesterase, and further suggest that re-engineering the active site of a cholinesterase could result in enzymes with clinically relevant rates of nerve agent hydrolysis. Published by Elsevier Ireland Ltd.

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

    PubMed

    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.

  20. Sulfidation as a natural antidote to metallic nanoparticles is overestimated: CuO sulfidation yields CuS nanoparticles with increased toxicity in medaka (Oryzias latipes) embryos.

    PubMed

    Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin

    2015-02-17

    Sulfidation is considered as a natural antidote to toxicity of metallic nanoparticles (NPs). The detoxification contribution from sulfidation, however, may vary depending on sulfidation mechanisms. Here we present the dissolution-precipitation instead of direct solid-state-shell mechanism to illustrate the process of CuO-NPs conversion to CuS-NPs in aqueous solutions. Accordingly, the CuS-NPs at environmentally relevant concentrations showed much stronger interference on Japanese medaka (Oryzias latipes) embryo hatching than CuO-NPs, which was probably due to elevated free copper ions released from CuS-NPs, leading to significant increase in oxidative stress and causing toxicity in embryos. The larval length was significantly reduced by CuS-NPs, however, no other obviously abnormal morphological features were identified in the hatched larvae. Co-introduction of a metal ion chelator [ethylene diamine tetraacetic acid (EDTA)] could abolish the hatching inhibition induced by CuS-NPs, indicating free copper ions released from CuS-NPs play an important role in hatching interference. This work documents for the first time that sulfidation as a natural antidote to metallic NPs is being overestimated, which has far reaching implications for risk assessment of metallic NPs in aquatic environment.

  1. 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.

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

    PubMed

    Kapsimali, M; Bourrat, F; Vernier, P

    2001-03-12

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

  3. Expression of GFP in nuclear transplants generated by transplantation of embryonic cell nuclei from GFP-transgenic fish into nonenucleated eggs of medaka, Oryzias latipes.

    PubMed

    Niwa, K; Kani, S; Kinoshita, M; Ozato, K; Wakamatsu, Y

    2000-01-01

    In order to investigate whether foreign genes can be used as genetic markers of donor nuclei in fish nuclear transplantation, expression of the GFP gene derived from donor nuclei was examined in nuclear transplants in medaka (Oryzias latipes). Embryonic nuclei were obtained from blastula embryos produced by crossing of transgenic fish of the wild-type strain heterozygous for the GFP gene with nontransgenic ones or by mutual crossing between transgenic fish. The GFP gene was driven by the promoter of the medaka elongation factor gene, EF-1alpha-A, which is known to induce GFP expression in many tissues except for the muscle in the transgenic fish. The nuclei were transplanted into nonenucleated unfertilized eggs of the orange-red strain. Adult nuclear transplants were successfully obtained at the rate of about 2% of the operated eggs. They were triploid and had no reproductive potential. The GFP gene was expressed in embryos, fry, and adults of nuclear transplants in a pattern similar to that in the transgenic fish. These results indicate that GFP is useful as a foreign genetic marker of donor nuclei in fish nuclear transplantation.

  4. 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.

  5. 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

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

    PubMed

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

    2017-09-12

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

  7. Toxicity of oil sands acid-extractable organic fractions to freshwater fish: Pimephales promelas (fathead minnow) and Oryzias latipes (Japanese medaka).

    PubMed

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Farwell, Andrea J; Dixon, D George

    2017-03-01

    The Alberta oil sands are one of the largest global petroleum deposits and, due to non-release practices for oil sands process-affected waters, produced tailings are stored in large ponds. The acid extractable organic (AEO) compounds in oil sands process-affected water are of greatest concern due to their persistence and toxicity to a variety of aquatic biota. The present study evaluated the toxicity of the five AEO fractions to two fish species: Oryzias latipes (Japanese medaka) and Pimephales promelas (fathead minnow). The fractions (F1-F5) were comprised of AEO with increasing mean molecular weight and subsequent increases in cyclicity, aromaticity, degree of oxygenation, and heteroatom content. The lowest molecular weight fraction, F1, displayed the lowest acute toxicity to both fish species. For fathead minnow, F5 displayed the greatest toxic potency, while F2 to F4 displayed intermediate toxicities. For Japanese medaka, F2 and F3 displayed the greatest acute toxicities and F1, F4 and F5 were significantly less potent. Overall, fathead minnow were more acutely sensitive to AEO than Japanese medaka. The present study indicates that AEO toxicity may not be solely driven by a narcotic mode of action, but chemical composition such as aromaticity and heteroatom content and their relation to toxicity suggest other drivers indicative of additional modes of toxic action.

  8. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. 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.

  10. 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.

  11. 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.

  12. Novel method for the nuclear transfer of adult somatic cells in medaka fish (Oryzias latipes): use of diploidized eggs as recipients.

    PubMed

    Wakamatsu, Yuko

    2008-08-01

    Until recently, the nuclear transfer of adult somatic cell nuclei in fish has been unsuccessful. This is primarily because of chromosomal aberrations in nuclear transplants, which are thought to arise due to asynchrony between the cell cycles of the recipient egg and donor nucleus. We recently succeeded in circumventing this difficulty by using a new nuclear transfer method in medaka fish (Oryzias latipes). Instead of enucleated eggs, the method uses non-enucleated and diploidized eggs, obtained by retention of the second polar body release, as recipients in the nuclear transfer of primary culture cells from the caudal fin of an adult green fluorescent protein gene (GFP)-transgenic strain. We found that 2.7% of the reconstructed embryos grew into diploid and fertile adults exhibiting donor expression characteristics and transmission of the GFP marker gene to progeny. The mechanism underlying the generation of nuclear transplants using this method is unknown at present; however, analyses of donor and recipient nuclei behavior and the cytoskeletal mechanisms involved in the early developmental stages, as well as the special ability of diploidized eggs to facilitate reprogramming of the donor nuclei will result in elucidation of the mechanism.

  13. Nanosecond Pulsed Electric Field Suppresses Development of Eyes and Germ Cells through Blocking Synthesis of Retinoic Acid in Medaka (Oryzias latipes)

    PubMed Central

    Shiraishi, Eri; Hosseini, Hamid; Kang, Dong K.; Kitano, Takeshi; Akiyama, Hidenori

    2013-01-01

    Application of nanosecond pulsed electric fields (nsPEFs) has attracted rising attention in various scientific fields including medical, pharmacological, and biological sciences, although its effects and molecular mechanisms leading to the effects remain poorly understood. Here, we show that a single, high-intensity (10–30 kV/cm), 60-ns PEF exposure affects gene expression and impairs development of eyes and germ cells in medaka (Oryzias latipes). Exposure of early blastula stage embryos to nsPEF down-regulated the expression of several transcription factors which are essential for eye development, causing abnormal eye formation. Moreover, the majority of the exposed genetic female embryos showed a fewer number of germ cells similar to that of the control (unexposed) genetic male at 9 days post-fertilization (dpf). However, all-trans retinoic acid (atRA) treatment following the exposure rescued proliferation of germ cells and resumption of normal eye development, suggesting that the phenotypes induced by nsPEF are caused by a decrease of retinoic acid levels. These results confirm that nsPEFs induce novel effects during embryogenesis in medaka. PMID:23936463

  14. 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.

  15. Oral exposure of PBDE-47 in fish: toxicokinetics and reproductive effects in Japanese Medaka (Oryzias latipes) and fathead minnows (Pimephales promelas).

    PubMed

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

    2006-01-15

    The toxicokinetics of 2,2,4,4-tetrabromodiphenyl 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 h with peak levels occurring at 8 h. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 h 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 value for elimination half-life was determined to be 281 h 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. 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.

  17. 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.

  18. An oocyte-specific astacin family protease, alveolin, is released from cortical granules to trigger egg envelope hardening during fertilization in medaka (Oryzias latipes).

    PubMed

    Shibata, Yasushi; Iwamatsu, Takashi; Suzuki, Norio; Young, Graham; Naruse, Kiyoshi; Nagahama, Yoshitaka; Yoshikuni, Michiyasu

    2012-12-15

    It has long been hypothesized that in fishes the contents of cortical granules are involved in the hardening of egg envelope following fertilization. We previously purified the egg envelope hardening initiation factor from the exudates released from activated medaka (Oryzias latipes) eggs and tentatively termed this protein alveolin. Alveolin is a member of the astacin metalloprotease family and was proposed to be a protease which hydrolyzes ZPB at one restricted position to allow starting cross-linking with ZPC. Here, we investigated the complete pathway from biosynthesis and accumulation to secretion of alveolin. A single alveolin transcript was detected only in ovarian preparations, confirming the specific expression of alveolin in the ovary. In situ hybridization indicated that the alveolin mRNA is already expressed in the very early previtellogenic oocytes. However, immunocytochemical studies revealed that the appearance of alveolin protein was delayed until the beginning of the vitellogenic stage. The cortical granules isolated from unfertilized eggs contained a high molecular weight form of glycosylated alveolin with a 50kDa relative molecular mass. Hypotonic treatment burst isolated granules in vitro and transformed alveolin to a 21.5kDa form, which is the same size as that of natural alveolin released from eggs upon fertilization. This transformation was inhibited in the presence of leupeptin and 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF), suggesting that a serine protease is involved in alveolin activation upon fertilization. Furthermore, the phylogenetic relationship of alveolin with other vertebrate astacin family members was analyzed. The result shows that alveolin and its teleostean homologs make a new group which is separate from either the hatching enzyme, meprin and BMP1/tolloid groups.

  19. 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

    2016-01-05

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

  20. Full life-cycle assessment of gene flow consistent with fitness differences in transgenic and wild-type Japanese medaka fish (Oryzias latipes).

    PubMed

    Pennington, Kelly M; Kapuscinski, Anne R; Morton, Michael S; Cooper, Anne M; Miller, Loren M

    2010-01-01

    Transgenic fish in development for aquaculture could escape from farms and interbreed with wild relatives in the nearby environment. Predicting whether escapes would result in transgene introgression is a major challenge in assessing environmental risks of transgenic fish. Previous studies have simulated gene flow from transgenic fish using mathematical modeling of fitness traits to predict the relative selective value of transgenic genotypes. Here, we present the first study of gene flow over the full life cycle in openly-breeding populations of transgenic animals, along with measurement of fitness traits. We conducted two invasion experiments in which we released two lines of growth-enhanced transgenic fish (T67 and T400), Japanese medaka (Oryzias latipes), into populations of wild-type (W) medaka in structured mesocosms. After several generations, the frequency of transgenic fish varied across replicates in the first invasion experiment (6 months), but the frequency of transgenic fish decreased in the second experiment (19 months). We also measured selected fitness traits in transgenic and wild-type medaka because these traits could be used to predict the relative selective value of a genotype. We found that: T400 males were more fertile than W males; offspring of W females lived longer than those with transgenic mothers; and W and T67 females reached sexual maturity sooner than T400 females. In contrast with other research that reported larger transgenic males had a mating advantage, we found that W males obtained more matings with females than T males; genetic background effects may account for our differing results as we compared W and T fish derived from different strains. The decreasing frequency of transgenic fish in the second invasion experiment suggests that transgenic fish had a selective disadvantage in the experimental environment. Our finding of transgenic advantage of some fitness traits and wild-type advantage in others is consistent with our

  1. Expression of 3β-hydroxysteroid dehydrogenase (hsd3b), star and ad4bp/sf-1 during gonadal development in medaka (Oryzias latipes).

    PubMed

    Nakamoto, Masatoshi; Fukasawa, Motoaki; Tanaka, Satomi; Shimamori, Kazusuke; Suzuki, Aya; Matsuda, Masaru; Kobayashi, Tohru; Nagahama, Yoshitaka; Shibata, Naoki

    2012-04-01

    In most vertebrates, sex steroids play a critical role in gonadal development, maturation of germ cells, and development of secondary sexual characteristics. Sex steroids are synthesized in steroid-producing cells (SPCs) in the testis known as Leydig cells, as well as in thecal and granulosa cells in the ovary. In SPCs, cholesterol is sequentially catalyzed by a set of steroidogenic factors and enzymes in order to produce sex steroids. Therefore, integrated expression of the genes involved in steroidogenesis is critical for the proper production of sex steroids. In the present study, regulatory mechanisms of steroidogenic factors and enzymes were examined. We focused on hsd3b, star and ad4bp/sf-1 as well as the description of temporal and spatial expression of these genes during gonadal development in medaka (Oryzias latipes). During testicular development, hsd3b, star and ad4bp/sf-1 were co-expressed in the interstitial somatic cells subsequent to the formation of the seminiferous tubule precursor, suggesting that ad4bp/sf-1 regulated the transcription of both hsd3b and star. During ovarian development, the expression pattern of hsd3b coincided with that of cyp11a1, but not with that of aromatase. Although ad4bp/sf-1 was mainly expressed in presumptive follicular cells, it was also detected in hsd3b positive interstitial cells in the developing ovary. Contrary to our expectations, the onset of star expression occurred during a later stage of ovarian development than the expression of other steroidogenic enzymes. Thus, the regulation mechanism of star transcription appears to differ from that of the other steroidogenic enzymes in the developing ovary, but not in the developing testis.

  2. Short-term effects of endocrine-disrupting chemicals on the expression of estrogen-responsive genes in male medaka (Oryzias latipes).

    PubMed

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

    2005-04-30

    To evaluate the estrogenic activities of selected estrogenic compounds such as estradiol-17beta (E2), nonylphenol (NP), 4-(1-adamantyl)phenol (AdP), bisphenol A (BPA), BPA metabolite 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) and 4,4'-dihydroxy-alpha-methylstilbene (DHMS) in the shortest possible time, we investigated the expression of estrogen-responsive genes such as vitellogenin I, vitellogenin II and alpha-type estrogen receptor genes in the liver of male medaka (Oryzias latipes) using reverse transcription-polymerase chain reaction (RT-PCR) techniques. These estrogen-responsive genes responded rapidly to selected estrogenic compounds after 8 h exposure, and the expression of hepatic vitellogenin II and estrogen receptor alpha mRNA was found to be more responsive than that of vitellogenin I mRNA. As a result, the relative estrogenic potencies of tested chemicals descended in the order of E2 (100)>MBP (0.38)>AdP (0.25)>DHMS (0.05)>NP (0.02)>BPA (0.001). Moreover, this preliminary study indicates that AdP and DHMS should be considered as candidate estrogenic compounds with the potential to induce hepatic estrogen-responsive genes in male medaka. These results suggest that vitellogenin I, vitellogenin II and estrogen receptor alpha gene expression patterns alter in male medaka treated with selected estrogenic compounds, and that these genes may be useful molecular biomarkers for screening estrogenic endocrine-disrupting chemicals in the shortest possible time.

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

    SciTech Connect

    Shima, A.; Shimada, A. )

    1991-03-15

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

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

    PubMed

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

    2017-01-01

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

  5. A fourth subtype of retinoic acid receptor-related orphan receptors is activated by oxidized all-trans retinoic acid in medaka (Oryzias latipes).

    PubMed

    Sakai, Kotowa; Fukushima, Haruka; Yamamoto, Yuya; Ikeuchi, Toshitaka

    2017-01-01

    The three known subtypes of the retinoic acid receptor-related orphan receptor (ROR) have been implicated in the control of immunity, brain function, and circadian rhythm in mammals. Here, we demonstrate by phylogenetic analysis that there were originally four subtypes of RORs in vertebrates. One of the novel ror paralogs, rord1 (rorca in the Ensembl database), is conserved among teleosts, but absent in mammals. Using medaka (Oryzias latipes) as a model teleost, we evaluated the expression pattern of this gene, its transactivational properties for endogenic chemicals, and its ability to activate the promoters of putative target genes. In eyes, the transcript of rord1 was expressed at higher levels during the day than at night. Interestingly, cholesterol derivatives, which are well-known ligands for mammalian RORs, did not efficiently promote transcriptional activity via RORd1. Thus we sought to identify the ligands that regulate the transcriptional activity of RORd1 using a luciferase reporter cell-based screening system. Using this system, we identified two metabolites of all-trans retinoic acid (ATRA), 4OH-ATRA and 4-keto ATRA, as potential ligands of RORd1. Moreover, RORd1 activated the promoter of cyp26a1 in a 4OH-ATRA -dependent manner. A novel ror subtype, rord has two paralogs, rord1 and rord2, in teleost. Rord1 mRNA is highly abundant in the eyes of medaka during light periods, suggesting that rord1 expression is involved in the regulation of circadian rhythm. We identified two ATRA metabolites, 4OH-ATRA and 4 K-ATRA, as endogenous candidate ligands of RORd1. We also show that 4-oxygenated ATRA metabolites have the potential to activate cyp26a1, the metabolic enzyme of ATRA. Our results support the notion that RORd1 is involved in the metabolism of ATRA in medaka.

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

    PubMed

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

    2015-12-01

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

  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.

    PubMed

    Foran, Christy M; Peterson, Bethany N; Benson, William H

    2002-08-01

    17alpha-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 low concentrations has the potential to disrupt the development of normal endocrine and reproductive function when exposure occurs during critical periods in development. Japanese medaka, Oryzias latipes, were used to evaluate the effect of exposure to EE during development on adult reproduction and endocrine function and the sensitivity of these animals to estrogen exposure as adults. To determine if the response to exogenous estrogen stimulation was diminished or sensitized, adults resulting from the developmental exposure groups were reexposed to EE at respectively higher concentrations. Hatchling exposure produced no changes in adult vitellogenin (VTG) content in the liver or circulating steroid concentrations, nor was reproduction affected. Reexposure of these adults inhibited reproduction, increased hepatic VTG and ER, and increased estrogen concentration measured in male plasma. Parental exposure produced permanent changes in hepatic content of ER and VTG in the adults resulting from exposure during gametogenesis and was related to a diminished response of males to subsequent estrogen exposure. The potential for this transgenerational exposure to decrease the responsiveness of males to EE is supported by comparing the concentration-response curves for hepatic VTG and ER in males exposed in ovo and as hatchlings. Our results indicate that the relationship between biomarkers and estrogen exposure will be altered by the timing and frequency of exposure.

  8. TOXICITY OF EXTRACTS FROM MUNICIPAL WASTEWATER TO EARLY LIFE STAGES OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO EVALUATE REMOVALS OF MICROPOLLUTANTS BY WASTEWATER TREATMENT.

    PubMed

    Maya, Nicholas; Crispo, Calvin; McFarland, Victoria; Nasuhoglu, Deniz; Isazadeh, Siavash; Yargeau, Viviane; Metcalfe, Chris D

    2017-08-09

    Treatment of municipal wastewater reduces the concentrations of some pharmaceuticals and personal care products, hormones and drugs of abuse. However, reduced concentrations of these micropollutants in wastewater may not correlate with reduced toxicity, as transformations of micropollutants and/or the formation of disinfection by-products may generate toxic compounds. In this study, we prepared extracts by solid phase extraction of samples collected from wastewater treatment plants (WWTPs) at various stages of treatment and tested these extracts for toxicity to early life stages of Japanese medaka (Oryzias latipes). Toxicity data for extracts prepared from a WWTP with secondary treatment showed that the numbers of exposed embryos (n=12 per treatment) that did not hatch increased from 1/12 for the treatment with untreated effluent to 5/12 for the treatment with final treated effluent. For extracts prepared from a WWTP with tertiary treatment, toxicity among exposed embryos (n=12 per treatment) also increased with each step of wastewater treatment, as shown by mortalities of 2/12 and 8/12 in treatments with extracts from untreated and final treated effluent, respectively, as well as an increase in the numbers of embryos that did not hatch from 2/12 to 9/12 in treatments with untreated and final treated effluent, respectively. Ozonation of treated wastewater collected from a third WWTP caused a high incidence of delayed hatch in exposed embryos (n=24 per treatment). However, hatching success and the numbers of developmental abnormalities in embryos from this ozonation treatment were not different from controls. This study demonstrates the value of including toxicity testing to assess the effectiveness of technologies for treatment of municipal wastewater. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Estrogen alters gonadal soma-derived factor (Gsdf)/Foxl2 expression levels in the testes associated with testis-ova differentiation in adult medaka, Oryzias latipes.

    PubMed

    Kobayashi, Tohru; Chiba, Ayaka; Sato, Tadashi; Myosho, Taijun; Yamamoto, Jun; Okamura, Tetsuro; Onishi, Yuta; Sakaizumi, Mitsuru; Hamaguchi, Satoshi; Iguchi, Taisen; Horie, Yoshifumi

    2017-10-01

    Testis-ova differentiation in sexually mature male medaka (Oryzias latipes) is easily induced by estrogenic chemicals, indicating that spermatogonia persist in sexual bipotentiality, even in mature testes in medaka. By contrast, the effects of estrogen on testicular somatic cells associated with testis-ova differentiation in medaka remain unclear. In this study, we focused on the dynamics of sex-related genes (Gsdf, Dmrt1, and Foxl2) expressed in Sertoli cells in the mature testes of adult medaka during estrogen-induced testis-ova differentiation. When mature male medaka were exposed to estradiol benzoate (EB; 800ng/L), testis-ova first appeared after EB treatment for 14days (observed as the first oocytes of the leptotene-zygotene stage). However, the testis remained structurally unchanged, even after EB treatment for 28days. Although Foxl2 is a female-specific sex gene, EB treatment for 7days induced Foxl2/FOXL2 expression in all Sertoli cell-enclosed spermatogonia before testis-ova first appeared; however, Foxl2 was not detected in somatic cells in control testes. Conversely, Sertoli-cell-specific Gsdf mRNA expression levels significantly decreased after EB treatment for 14days, and no changes were observed in DMRT1 localization following EB treatment, whereas Dmrt1 mRNA levels increased significantly. Furthermore, after EB exposure, FOXl2 and DMRT1 were co-localized in Sertoli cells during testis-ova differentiation, although FOXL2 localization was undetectable in Sertoli-cell-enclosed apoptotic testis-ova, whereas DMRT1 remained localized in Sertoli cells. These results indicated for the first time that based on the expression of female-specific sex genes, feminization of Sertoli cells precedes testis-ova differentiation induced by estrogen in mature testes in medaka; however, complete feminization of Sertoli cells was not induced in this study. Additionally, it is suggested strongly that Foxl2 and Gsdf expression constitute potential molecular markers for

  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 estrogenic activity, and phytoestrogen and organochlorine pesticide contents in an experimental fish diet on reproduction and hepatic vitellogenin production in medaka (Oryzias latipes).

    PubMed

    Inudo, Makiko; Ishibashi, Hiroshi; Matsumura, Naomi; Matsuoka, Munekazu; Mori, Taiki; Taniyama, Shigeto; Kadokami, Kiwao; Koga, Minoru; Shinohara, Ryota; Hutchinson, T H; Iguchi, Taisen; Arizono, Koji

    2004-12-01

    Endocrine-disrupting chemicals (EDCs) are giving rise to serious concerns for humans and wildlife. Phytoestrogens, such as daidzein and genistein in plants, and organochlorine pesticides are suspected EDCs, because their chemical structure is similar to that of natural or synthetic estrogens and they have estrogenic activity in vitro and in vivo. We assessed estrogenic activity and dietary phytoestrogen and organochlorine pesticide contents of various fish diets made in the United Kingdom, and compared them with those features of diets made in Japan that were tested in a previous study. Genistein and daidzein were detected in all of the diets. Using an in vitro bioassay, many of these diets had higher activation of estrogen beta-receptors than estrogen alpha-receptors. Organochlorine pesticides such as hexachlorobenzene, beta-benzene hexachloride (BHC), and gamma-BHC were detected in all fish diets. On the basis of these data, we investigated the effect of differing dietary phytoestrogen content in Japanese fish diets on hepatic vitellogenin production and reproduction (fecundity and fertility) in medaka (Oryzias latipes). Assessment of the effects of a 28-day feeding period on reproduction of paired medaka did not indicate significant differences in the number of eggs produced and fertility among all feeding groups. However, hepatic vitellogenin values were significantly higher for male medaka fed diet C (genistein, 58.5 +/- 0.6 microg/g; daidzein, 37.3 +/- 0.2 microg/g) for 28 days compared with those fed diet A (genistein, < 0.8 microg/g; daidzein, < 0.8 microg/g) or diet B (genistein, 1.4 +/- 0.1 microg/g; daidzein, 2.0 +/- 0.1 microg/g). Our findings indicate that fish diets containing high amounts of phytoestrogens, such as diet C, have the potential to induce hepatic vitellogenin production in male medaka, even if reproductive parameters are unaffected. Therefore, some diets, by affecting vitellogenin production in males, may alter estrogenic activity of in

  12. Effects of 4-tert-pentylphenol on the gene expression of P450 11beta-hydroxylase in the gonad of medaka (Oryzias latipes).

    PubMed

    Yokota, Hirofumi; Abe, Tatsuo; Nakai, Makoto; Murakami, Hidekazu; Eto, Chizumi; Yakabe, Yoshikuni

    2005-01-26

    Alkylphenols including 4-tert-pentylphenol (4-PP) have been shown to alter sexual differentiation in fish due to their estrogenic properties. Medaka (Oryzias latipes) is so sensitive to these substances because morphological sex reversal and testis-ova induction are well developed in the exposed males. However, little work has been done to characterize the molecular effects of estrogenic substances on the morphological and gonadal feminization in male fish. Cytochrome P450 11beta-hydroxylase (P450(11beta)) is a key steroidogenic enzyme in production of 11-ketotestosterone which is the predominant androgen in male fish. In this study, we cloned a cDNA encoding medaka testicular P450(11beta), and then investigated the gene expression of P450(11beta) in the testes of genetically male medaka exposed to 4-PP. The cDNA contains 1740 nucleotides that encode a protein of 543 amino acids, which shares 68.9% and 73.4% homology with testicular P450(11beta)s from Japanese eel (Anguilla japonica) and rainbow trout (Oncorhynchus mykiss), respectively. HeLa cells transfected with an expression vector containing the open reading frame of medaka P450(11beta) cDNA showed 11beta-hydroxylating activity in the presence of exogenous testosterone. Analysis of tissue distribution by RT-PCR showed great abundance of P450(11beta) mRNA in testis. In the partial life-cycle exposure with 4-PP, morphologically sex-reversal was observed in XY medaka exposed to 4-PP concentrations of > or =238 microg/L. Furthermore, exposure to 4-PP completely inhibited P450(11beta) mRNA expression in the gonads of sex-reversed XY fish at 60-day posthatch. These results suggest that xeno-estrogen 4-PP may have inhibitory effects on the synthesis of testicular 11-oxygenated androgens through downregulation of P450(11beta) expression in the genetically male fish.

  13. Permanent and functional male-to-female sex reversal in d-rR strain medaka (Oryzias latipes) following egg microinjection of o,p'-DDT.

    PubMed Central

    Edmunds, J S; McCarthy, R A; Ramsdell, J S

    2000-01-01

    Complete sex reversal of fish is accomplished routinely in aquaculture practices by exposing fish to exogenous sex steroids during gonadal differentiation. A variety of environmental chemicals are also active at sex steroid receptors and theoretically possess the potential to alter normal sexual differentiation in fish. However, in controlled environmental chemical exposures to date, only partial alterations of fish sexual phenotype have been observed. Here we report complete, permanent, and functional male-to-female sex reversal in the Japanese medaka (Oryzias latipes, d-rR strain) after a onetime embryonic exposure to the xenoestrogen o, p'-DDT. d-rR strain medaka are strict gonochorists that possesses both sex-linked pigmentation, which distinguishes genotypic sex, and sexually dimorphic external secondary sexual characteristics, which distinguish phenotypic sex. We directly microinjected the xenoestrogen o, p'-DDT into the egg yolks of medaka at fertilization to parallel the maternal transfer of lipophilic contaminants to the embryo. At 10 weeks of age, microinjected medaka were examined for mortality and sex reversal. A calculated embryonic dose of 511 +/- 22 ng/egg o, p'-DDT (mean +/- standard error) resulted in 50% mortality. An embryonic exposure of 227 +/- 22 ng/egg o, p'-DDT resulted in 86% (6 of 7) sex reversal of genetic males to a female phenotype (XY females). XY females were distinguished by sex-linked male pigmentation accompanying female secondary sexual characteristics. Histologic examination of the gonads confirmed active ovaries in 100% of the XY females. In 10-day breeding trials in which XY females were paired with normal XY males, 50% of the XY females produced fertilized embryos; this represents a comparable breeding success rate to normal XX females. Fertilized eggs produced from XY females hatched to viable larvae. These results clearly indicate that a weakly estrogenic pesticide, o, p'-DDT, when presented during the critical period of

  14. 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

  15. 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

  16. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces organ- specific differential gene expression in male Japanese medaka (Oryzias latipes).

    PubMed

    Volz, David C; Bencic, David C; Hinton, David E; Law, J McHugh; Kullman, Seth W

    2005-05-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental contaminant with well-known adverse effects in fish. In this study, we initially exploited suppression subtractive hybridization (SSH) as a screening tool to assess qualitative gene expression changes in whole brain, liver, and testis of adult male Japanese medaka (Oryzias latipes) exposed for 48 h to a single intraperitoneal-injected dose of TCDD (10 microg TCDD/kg body weight). Across these three organs, SSH identified a total of 335 unique genes. Each set of forward- and reverse-subtracted organ cDNA libraries consisted of a distinct gene list and corresponding distribution of biological processes, suggesting that transcript profiles of these libraries were highly organ-specific. Based on sequence match significance and frequencies within each set of organ libraries, genes hypothesized to be strongly responsive (42 total) within male medaka brain, liver, or testis were semi-quantitatively screened with replicate cDNA nylon membrane arrays. In addition, TCDD-treated male medaka were surveyed for gross histological analysis of brain, liver, and testis. In general, adverse histopathological changes were not observed in the brain, and glycogen depletion was observed only in the liver. However, significant histological changes occurred in the testis, and included disorganization of spermatogenesis at the testis periphery, disruption of the interstitium, Leydig cell swelling, and Sertoli cell vacuolation. Of the 42 genes screened by cDNA array analysis, cytochrome P450 1A (CYP1A) mRNA was the only transcript significantly higher in TCDD-exposed brain, whereas 12 transcripts (including CYP1A) were significantly higher in TCDD-exposed liver, and 34 transcripts were significantly lower in TCDD-exposed testis. Therefore, the degree of TCDD-induced alterations observed in each organ at a gross histological level corresponded well with the number and ontology of gene transcripts affected on the array

  17. 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.

  18. 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.

  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. Copyright © 2014 Elsevier Inc. All rights reserved.

  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; ...

    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. 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.

  2. 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.

  3. 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

  4. Isolation and characterization of a novel type of sialoglycoproteins (hyosophorin) from the eggs of medaka, Oryzias latipes: nonapeptide with a large N-linked glycan chain as a tandem repeat unit.

    PubMed

    Kitajima, K; Inoue, S; Inoue, Y

    1989-04-01

    We found a novel type of sialoglycoprotein (SGP) with apparent molecular mass ranging from 15,000 to 100,000 Da in the unfertilized eggs of the medaka fish, Oryzias latipes. From fertilized eggs we isolated the corresponding sialoglycopeptides of apparent molecular weight 7000. The amino acid and carbohydrate compositions of these glycoproteins and glycopeptides are very similar, if not identical, and they contain 90%, by weight, of carbohydrate, the predominant sugars being Gal, GlcNAc, and NeuAc. The chemical and physical data indicate that 15- to 100-kDa SGPs are made up of tandem repeat structures whose repeating unit is 7-kDa sialoglycopeptide, and, upon fertilization, higher molecular weight SGPs undergo proteolytic depolymerization to the least structural unit, 7-kDa sialoglycopeptide. As is the case with polysialoglycoproteins (PSGP) found in salmonid fish eggs, a novel family of sialoglycoproteins has been proven to be a major component of cortical alveoli of medaka eggs, namely, hyosophorin. However, we found that they differ markedly from PSGPs (salmonid fish egg hyosophorins) in terms of the carbohydrate composition. The chemical composition and the results of Smith degradation indicate that SGP contains one large N-linked glycan chain per repeat unit. We have determined the amino acid sequence of 7-kDa sialoglycopeptide: Asp-Ala-Ala-Ser-Asn*-Gln-Thr-Val-Ser, where * indicates the asparagine residue to which a large glycan chain consisting of Fuc2Man3Gal15GlcNac9NeuAc6 is attached. The direct experimental evidence for the presence of a polyprotein structure suggests that the covalent nature of the higher molecular weight SGPs should be expressed as [Asp-Ala-Ala-Ser-Asn*-Gln-Thr-Val-Ser]N, where N = 2 to 14 but for the major fraction N = 12.

  5. 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).

    PubMed

    Geter, David R; Winn, Richard N; Fournie, John W; Norris, Michelle B; DeAngelo, Anthony B; Hawkins, William E

    2004-03-12

    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 ability of MX to induce mutations was investigated in the liver of medaka (Oryzias latipes), a small fish model, utilizing the cII transgenic medaka strain that allows detection of in vivo mutations. Methylazoxymethanol acetate (MAMAc), a carcinogen in medaka, served as a positive control. Fish were exposed to MX at 0, 1, 10, or 30 mg/L for 96 h, whereas the MAMAc exposures were for 2 h at 0, 0.1, 1, or 10 mg/L. Both exposures were conducted under static water conditions and with fasted medaka. Following exposure, fish were returned to regular culture conditions to allow mutation expression for 15 or 40 d for MX or for 15 or 32 d for MAMAc. Mutations were not induced in medaka exposed to MX for 96 h. However, a concentration- and time-dependent increase in mutations was observed from the livers of fish exposed to 1 and 10 mg/L MAMAc. In conclusion, mutation induction was not observed in the livers of cII medaka exposed to MX for 96 h; however, studies are planned to examine mutation induction in the gills and skin to explore the possibility that MX-induced DNA damage occurs primarily in the tissues of initial contact.

  6. 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

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

    2011-01-01

    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 days 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.

  7. Ol-Prx 3, a member of an additional class of homeobox genes, is unimodally expressed in several domains of the developing and adult central nervous system of the medaka (Oryzias latipes).

    PubMed

    Joly, J S; Bourrat, F; Nguyen, V; Chourrout, D

    1997-11-25

    Large-scale genetic screens for mutations affecting early neurogenesis of vertebrates have recently been performed with an aquarium fish, the zebrafish. Later stages of neural morphogenesis have attracted less attention in small fish species, partly because of the lack of molecular markers of developing structures that may facilitate the detection of discrete structural alterations. In this context, we report the characterization of Ol-Prx 3 (Oryzias latipes-Prx 3). This gene was isolated in the course of a large-scale screen for brain cDNAs containing a highly conserved DNA binding region, the homeobox helix-three. Sequence analysis revealed that this gene belongs to another class of homeobox genes, together with a previously isolated mouse ortholog, called OG-12 [Rovescalli, A. C., Asoh, S. & Nirenberg, M. (1996) Proc. Natl. Acad. Sci. USA 93, 10691-10696] and with the human SHOX gene [Rao, E., Weiss, B., Fukami, M., Rump, A., Niesler, B., et al. (1997) Nat. Genet. 16, 54-62], thought to be involved in the short-stature phenotype of Turner syndrome patients. These three genes exhibit a moderate level of identity in the homeobox with the other genes of the paired-related (PRX) gene family. Ol-Prx 3, as well as the PRX genes, are expressed in various cartilaginous structures of head and limbs. These genes might thus be involved in common regulatory pathways during the morphogenesis of these structures. Moreover, this paper reports a complex and monophasic pattern of Ol-Prx 3 expression in the central nervous system, which differs markedly from the patterns reported for the PRX genes, Prx 3 excluded: this gene begins to be expressed in a variety of central nervous system territories at late neurula stage. Strikingly, it remains turned on in some of the derivatives of each territory during the entire life of the fish. We hope this work will thus help identify common features for the PRX 3 family of homeobox genes.

  8. 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

  9. Evidence for Different Origins of Sex Chromosomes in Closely Related Oryzias Fishes: Substitution of the Master Sex-Determining Gene

    PubMed Central

    Tanaka, Keita; Takehana, Yusuke; Naruse, Kiyoshi; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

    2007-01-01

    The medaka Oryzias latipes and its two sister species, O. curvinotus and O. luzonensis, possess an XX–XY sex-determination system. The medaka sex-determining gene DMY has been identified on the orthologous Y chromosome [O. latipes linkage group 1 (LG1)] of O. curvinotus. However, DMY has not been discovered in other Oryzias species. These results and molecular phylogeny suggest that DMY was generated recently [∼10 million years ago (MYA)] by gene duplication of DMRT1 in a common ancestor of O. latipes and O. curvinotus. We identified seven sex-linked markers from O. luzonensis (sister species of O. curvinotus) and constructed a sex-linkage map. Surprisingly, all seven sex-linked markers were located on an autosomal linkage group (LG12) of O. latipes. As suggested by the phylogenetic tree, the sex chromosomes of O. luzonensis should be “younger” than those of O. latipes. In the lineage leading to O. luzonensis after separation from O. curvinotus ∼5 MYA, a novel sex-determining gene may have arisen and substituted for DMY. Oryzias species should provide a useful model for evolution of the master sex-determining gene and differentiation of sex chromosomes from autosomes. PMID:17947439

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

    USGS Publications Warehouse

    Papoulias, Diana M.; Tillitt, Donald E.; Talykina, 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.

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

    PubMed

    Sekimizu, Koshin; Tagawa, Masatomo; Takeda, Hiroyuki

    2007-07-01

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

  12. 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.

  13. Nuclear transfer of embryonic cell nuclei to non-enucleated eggs in zebrafish, Danio rerio.

    PubMed

    Hattori, Manabu; Hashimoto, Hisashi; Bubenshchikova, Ekaterina; Wakamatsu, Yuko

    2011-04-15

    We previously established a novel method for nuclear transfer in medaka (Oryzias latipes) using non-enucleated, diploidized eggs as recipients for adult somatic cell nuclei. Here we report the first attempt to apply this method to another fish species. To examine suitability of using non-enucleated eggs as recipients for nuclear transfer in the zebrafish (Danio rerio), we transferred blastula cell nuclei from a wild-type donor strain to non-enucleated, unfertilized eggs from a golden recipient strain. As a result, 31 of 184 (16.8%) operated eggs developed normally and reached the adult stage. Twenty-eight (15.2%) of these transplants showed wild-type phenotype and the remaining three (1.6%) were golden. Except for one individual that exhibited diploid/tetraploid mosaicism, all of the wild-type nuclear transplants were either triploid or diploid. While all of 19 triploid transplants were infertile, a total of six transplants (21.4%) were fertile (five of the eight diploid transplants and one transplant exhibiting ploidy mosaicism). Except for one diploid individual, all of the fertile transplants transferred both the wild-type golden gene allele (slc24a5) as well as the phenotype, the wild-type body color, to their F(1) and F(2) progeny in a typical Mendelian fashion. PCR analysis of slc24a5 suggested that triploidy originated from a fused nucleus in the diploid donor and haploid recipient nuclei, and that the sole origin of diploidy was the diploid donor nucleus. The results of the present study demonstrated the suitability of using non-enucleated eggs as recipients for nuclear transfer experiments in zebrafish.

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

    PubMed

    2005-10-01

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

  15. Telomerase Expression in Medaka ( Oryzias melastigma) Pharyngeal Teeth.

    PubMed

    Tan, W H; Witten, P E; Winkler, C; Au, D W T; Huysseune, A

    2017-06-01

    Nonmammalian vertebrates have the capacity of lifelong tooth replacement. In all vertebrates, tooth formation requires contact and interaction between the oral or pharyngeal epithelium and the underlying mesenchyme. To secure lifelong replacement, the presence of odontogenic stem cells has been postulated, particularly in the epithelial compartment. This study uses an advanced teleost fish species, the marine medaka Oryzias melastigma, a close relative to Oryzias latipes, to examine the expression and distribution of telomerase reverse transcriptase (Tert), the catalytic unit of telomerase, in developing pharyngeal teeth and to relate these data to the proliferative activity of the cells. The data are complemented by expression analysis of the pluripotency marker oct4 and bona fide stem cell marker lgr5. Tert distribution and tert expression in developing tooth germs show a dynamic spatiotemporal pattern. Tert is present first in the mesenchyme but is downregulated as the odontoblasts differentiate. In contrast, in the epithelial enamel organ, Tert is absent during early stages of tooth formation and upregulated first in ameloblasts. Later, Tert is expressed and immunolocalized throughout the entire inner enamel epithelium. The pattern of Tert distribution is largely mutually exclusive with that of proliferating cell nuclear antigen (PCNA) immunoreactivity: highly proliferative cells, as revealed by PCNA staining, are negative for Tert; conversely, PCNA-negative cells are Tert-positive. Only the early condensed mesenchyme is both Tert- and PCNA-positive. The absence of tert-positive cells in the epithelial compartment of early tooth germs is underscored by the absence of oct4- and lgr5-positive cells, suggesting ways other than stem cell involvement to secure continuous renewal.

  16. 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.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

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

  19. RELATIONSHIP BETWEEN PHYSIOLOGICAL RESPONSES AND REPRODUCTIVE IMPAIRMENT IN JAPANESE MEDAKA (ORYZIAS LATIPES): EFFECTS OF ETHINYLESTRADIOL

    EPA Science Inventory

    Previous studies have measured various physiological responses in fish from exposure to endocrine disrupting compounds, while others have observed higher level effects on reproduction and development. However, little is understood about the relationship that might exist between a...

  20. 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...

  1. Ammonium-dependent sodium uptake in mitochondrion-rich cells of medaka (Oryzias latipes) larvae.

    PubMed

    Wu, Shu-Chen; Horng, Jiun-Lin; Liu, Sian-Tai; Hwang, Pung-Pung; Wen, Zhi-Hong; Lin, Chan-Shing; Lin, Li-Yih

    2010-02-01

    In this study, a scanning ion-selective electrode technique (SIET) was applied to measure H(+), Na(+), and NH(4)(+) gradients and apparent fluxes at specific cells on the skin of medaka larvae. Na(+) uptake and NH(3)/NH(4)(+) excretion were detected at most mitochondrion-rich cells (MRCs). H(+) probing at MRCs revealed two group of MRCs, i.e., acid-secreting and base-secreting MRCs. Treatment with EIPA (100 muM) blocked 35% of the NH(3)/NH(4)(+) secretion and 54% of the Na(+) uptake, suggesting that the Na(+)/H(+) exchanger (NHE) is involved in Na(+) and NH(3)/NH(4)(+) transport. Low-Na(+) water (<0.001 mM) or high-NH(4)(+) (5 mM) acclimation simultaneously increased Na(+) uptake and NH(3)/NH(4)(+) excretion but decreased or even reversed the H(+) gradient at the skin and MRCs. The correlation between NH(4)(+) production and H(+) consumption at the skin surface suggests that MRCs excrete nonionic NH(3) (base) by an acid-trapping mechanism. Raising the external NH(4)(+) significantly blocked NH(3)/NH(4)(+) excretion and Na(+) uptake. In contrast, raising the acidity of the water (pH 7 to pH 6) enhanced NH(3)/NH(4)(+) excretion and Na(+) uptake by MRCs. In situ hybridization and real-time PCR showed that the mRNAs of the Na(+)/H(+) exchanger (slc9a3) and Rhesus glycoproteins (Rhcg1 and Rhbg) were colocalized in MRCs of medaka, and their expressions were induced by low-Na(+) acclimation. This study suggests a novel Na(+)/NH(4)(+) exchange pathway in apical membranes of MRCs, in which a coupled NHE and Rh glycoprotein is involved and the Rh glycoprotein may drive the NHE by generating H(+) gradients across apical membranes of MRCs.

  2. Dietary resveratrol improves immunity but reduces reproduction of broodstock medaka Oryzias latipes (Temminck & Schlegel).

    PubMed

    Kowalska, Agata; Siwicki, Andrzej K; Kowalski, Radosław K

    2017-02-01

    Here, we investigated the effect of dietary resveratrol (20, 40, and 80 µg/g BW/day) on cell-mediated immunity (activity of spleen phagocytes and proliferative response of lymphocytes) and reproductive parameters (egg and sperm quality, i.e. fecundity-total number of eggs produced by individual fish, fertility, embryo survival, and hatching rate) in medaka. Fish fed feed with resveratrol at 40 and 80 µg/g BW/day had significantly higher metabolic activity and intracellular phagocyte killing activity than control. The proliferative lymphocyte activity of the fish from R80 group was greater by more than 20 % in comparison with the control group (P < 0.05). The percentage of macrophages (MO) and their mean fluorescence intensities (MFI) in R40 and R80 groups were significantly higher compared to C and R20 groups (P < 0.05). The differences in MO and MFI values ranged from 52.5 % (±1.5; R0 group) to 65.8 % (±1.6; R80 group) and from 23.2 (±1.4; R0 group) to 38.2 (±2.4; R80 group), respectively. Moreover, resveratrol at 80 µg/g BW/day decreased liver COX activity, i.e. 5.4 in R80 group and 7.9 in R0 group (P < 0.05). The motility parameters of the sperm obtained from the males fed feed supplemented with resveratrol at 80 µg/g BW/day exhibited the highest values except the linearity, which was lower as compared to the control (P < 0.05). The results indicate that diet supplemented with resveratrol at a dosage of 40 µg/g BW/day improves phagocyte killing ability and lymphocyte proliferation in broodstock and accelerates offspring hatch. Also, the results suggest that COX activity influences sperm and oocyte quality in fish; the presence of a COX inhibitor in the dose of 40 µg/g BW/day decreased the embryo survival.

  3. 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...

  4. Genetic analysis of vertebral regionalization and number in medaka (Oryzias latipes) inbred lines.

    PubMed

    Kimura, Tetsuaki; Shinya, Minori; Naruse, Kiyosi

    2012-11-01

    Vertebral number is the most variable trait among vertebrates. In addition to the vertebral number, the ratio of abdominal to caudal vertebrae is a variable trait. The vertebral number and the ratio of abdominal to caudal vertebrae contribute to vertebrate diversity. It is very interesting to know how to determine the vertebral number and the ratio of abdominal to caudal vertebrae. In this study, we identify differences in the vertebral number and the ratio of abdominal vertebrae to vertebral number between two inbred lines of medaka, namely, Hd-rRII1 and Kaga. To identify the genetic factor of those differences, we performed quantitative trait locus (QTL) analysis for vertebral number and the ratio of abdominal vertebrae to vertebral number using 200 F(2) fish. Our results show a suggestive QTL of the ratio of abdominal vertebrae to vertebral number on chromosome 15, and five QTL of vertebral number on chromosomes 1, 10, 11, 17, and 23. The QTL on chromosome 15 contains hoxDb cluster genes. The QTL of vertebral number include some genes related to the segmentation clock and axial elongation. In addition, we show that the difference in vertebral number between two inbred lines is derived from differences in the anteroposterior length of somites. Our results emphasize that the developmental process should be considered in genetic analyses for vertebral number.

  5. 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...

  6. Differential genetic responses to ionizing irradiation in individual families of Japanese medaka, Oryzias latipes.

    PubMed

    Tsyusko, O; Glenn, T; Yi, Y; Joice, G; Jones, K; Aizawa, K; Coughlin, D; Zimbrick, J; Hinton, T

    2011-01-10

    Although no statistically significant hereditary effects have yet been detected in the children of survivors from the atomic bombings in Hiroshima and Nagasaki, recent animal studies have found that exposure to ionizing radiation can cause genomic and epigenomic instability in the exposed individuals, as well as their offspring, and therefore, may have much larger genetic effects than predicted by earlier studies. When individuals are exposed to various environmental insults, including radiation, individual sensitivity to the insults often varies. Variance in germ-line response to radiation among individuals has been widely recognized, but it is difficult to address due to the use of inbred strains and the limited number of offspring that can be produced by a pair of mice, the common model used to study genetic effects of radiation. Herein is the first study to examine individual family responses to ionizing radiation using a parent-pedigree approach in an outbred strain of a vertebrate model, the Japanese medaka fish. Changes in frequencies of radiation-induced germline mutations at nine microsatellite loci were examined in the same families before and after exposure to one of four acute doses of ionizing radiation (0.1, 0.5, 2.5, 5Gy, plus sham-exposed controls). Families varied significantly in pre-exposure mutation frequencies and responses to irradiation, but germline mutations were elevated in at least one family after 0.1, 0.5, and 5Gy exposures. Variance among individuals in sensitivity to radiation is well documented for many endpoints, and our work now extends these endpoints to include germ-line mutations. Further studies are needed to elucidate dose response, effects at varying stages of spermatogenesis, and the mechanisms underlying the variance in these individual responses to radiation.

  7. Valproate-induced teratogenesis in Japanese rice fish (Oryzias latipes) embryogenesis.

    PubMed

    Wu, Mengmeng; Khan, Ikhlas A; Dasmahapatra, Asok K

    2012-04-01

    Fertilized eggs of Japanese rice fish (medaka) at three developmental stages (Iwamatsu stages 4-30) were exposed to waterborne valproic acid (VPA) (0-80 mM) in hatching solution for 48 h. The amount of valproate to cause 50% mortality (IC(50)) is found to be developmental stage-specific. The embryos were more sensitive to valproate at early stages of development (Iwamatsu stages 4-10) than in the embryos in late stages (Iwamatsu stages 17-30). Valproate exposed embryos have microcephaly and disrupted cardiovasculature with delayed vessel circulation, thrombus formation, and slow heart rate. The hatching efficiency is also reduced by valproate exposure due to developmental delay. The mRNA analysis of nine genes belong to oxidative stress (catalase, gsr, gst), neurogenesis (iro3, wnt1, shh, otx2, nlgn3b) and cell cycle regulation (ccna2) have been done. It was observed that the genes belong to oxidative stress remained unaltered after valproate exposure. However, some of the genes belong to neurogenesis (wnt1,shh, otx2 and nlgn3b) and cell cycle (ccna2) showed developmental stage-specific alteration after valproate exposure. This study indicates that valproate is able to induce some of the phenotypic features which are analogous to human fetal valproate syndrome (FVS). Modulation of genes expressed in neural tissues indicates that this fish can be used to analyze the mechanisms of many neurobehavioral disorders like Autism spectrum disorder (ASD) in human.

  8. 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...

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

    PubMed Central

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

    2015-01-01

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

  10. Osterix/Sp7 regulates biomineralization of otoliths and bone in medaka (Oryzias latipes).

    PubMed

    Renn, Jörg; Winkler, Christoph

    2014-02-01

    Osterix/Sp7 is a zinc finger transcription factor and critical regulator of osteoblast differentiation, maturation and activity. Osterix expression has also been described in non-skeletal tissues but functional analyses are lacking. In the present study, we show that in the teleost model medaka, osterix is present as two alternatively spliced transcripts, osx_tv1 and osx_tv2. Knock-down of osx_tv1 and/or osx_tv2 results in mineralization loss in early intramembranous bones while cartilage formation is mostly unaffected. Formation of the parasphenoid, the earliest mineralized bone in the medaka skeleton, is impaired and fails to recover at later stages. Ossification of later bones, such as the operculum and cleithrum, is delayed but recovers during further development. In the axial skeleton, formation of the neural arches and centra is strongly delayed. In vivo analyses using osterix:nlGFP and osteocalcin:GFP transgenic medaka and whole mount in situ hybridization suggest that bone defects observed after knock-down of osterix are caused by a delay of osteoblast maturation and activity. Furthermore, we analyzed expression profile and function of osterix during ear and otolith formation. We show that osterix is expressed in otic placodes at the otic vesicle stage and that its knock-down results in a loss of otoliths. Taken together, we show that osterix is required for bone formation in a teleost fish and that its important regulatory functions are conserved between teleosts and mammals. Furthermore, we provide the first functional evidence for a role of Osterix in a non-skeletal tissue, i.e. the otoliths.

  11. 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. © 2015 Japanese Society of Developmental Biologists.

  12. In vitro and in vivo estrogenic effects of 17alpha-estradiol in medaka (Oryzias latipes).

    PubMed

    Huang, Chong; Zhang, Zhaobin; Wu, Shimin; Zhao, Yanbin; Hu, Jianying

    2010-07-01

    17alpha-Estradiol (17alpha-E2), the stereoisomer of 17beta-estradiol (17beta-E2), is considered a weak estrogen in mammals. However, little is known about its estrogenic potency in teleost fish, even though 17alpha-E2 has been frequently detected in aquatic environment. To investigate the estrogenic activity of 17alpha-E2, an in vitro assay based on the ligand-dependent interaction between medaka estrogen receptor alpha (med-ERalpha) and coactivator was conducted. Japanese medaka (Oryziaslatipes) were exposed to 1, 10, 100, 1000 and 10000ng L(-1) 17alpha-E2 (actual concentrations of 1.91, 12.81, 96.24, 1045.15, and 9320.81ng L(-1), respectively) for 3 weeks, and expression for vitellogenins (VTG-I), Choriogenin H (CHG-H) and estrogen receptor alpha (ERalpha) mRNA in the livers was analyzed by quantitative real-time RT-PCR (Q-RT-PCR). The in vitro study showed that the EC(50) of 17alpha-E2 was 114.10nM, which was 30 times less potent than that of 17beta-E2 (3.80nM). Dose-dependent induction of gene expression of VTG-I, CHG-H and ERalpha were observed. The benchmark dose (BMD) values for VTG-I, CHG-H and ERalpha were 44.16ng L(-1), 15.25ng L(-1) and 66.03ng L(-1), which were about 11-, 17- and 14-times less potent than that of 17beta-E2, respectively. Comparing this study with those reported previously in mammals, it is suggested that fish species may be more susceptive to 17alpha-E2 than mammals.

  13. 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.

  14. 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).

  15. GENDER-SPECIFIC GROWTH AND HEPATIC NEOPLASIA IN 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...

  16. 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 ...

  17. 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...

  18. LARGE SCALE CARCINOGEN DOSE RESPONSE STUDIES WITH JAPANESE MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    To investigate the responses to low carcinogen doses in animal models, large sample sizes are needed and it is an advantage if the model has a low spontaneous tumor rate. Three large scale dose response studies were conducted using Japanese medaka and the carcinogen diethylnitros...

  19. Induced histopathologic alterations in early life stages (ELS) of medaka (Oryzias latipes)

    SciTech Connect

    Villalobos, S.A.; Gonzalez, M.; Hinton, D.E.

    1994-12-31

    Agricultural and industrial pollutants cause extensive alterations in fish embryos, and the cardiovascular system is often targeted. Dioxin and dioxin-like compounds produce lesions in lake and rainbow trout (Salvelinus namaycush and Oncorhynchus mykiss), and northern pike (Esox lucius), ultimately compromising ELS survival, and possibly stock recruitment. Pericardial edema was produced by exposure of medaka embryos to thiobencarb, molinate, 1,3-dinitrobenzene, dioxin, and products of incomplete combustion from trichloroethylene incineration. These lesions closely resembled those observed in birds, Xenopus, and other fish species. This work focuses on gross morphologic and histologic alterations of heart, major blood vessels, pericardial cavity, skeletal muscle, and brain. Endothelium, perivascular connective tissue, and other tissues of embryos and larvae were examined in semithin (4 {mu}m) glycolmethacrylate-embedded serial sections. Structural defects and their microscopic features will be presented.

  20. Developmental neurotoxicity of organophosphate flame retardants in early life stages of Japanese medaka (Oryzias latipes).

    PubMed

    Sun, Liwei; Tan, Hana; Peng, Tao; Wang, Sisi; Xu, Wenbin; Qian, Haifeng; Jin, Yuanxiang; Fu, Zhengwei

    2016-12-01

    Because brominated flame retardants are being banned or phased out worldwide, organophosphate flame retardants have been used as alternatives on a large scale and have thus become ubiquitous environmental contaminants; this raises great concerns about their environmental health risk and toxicity. Considering that previous research has identified the nervous system as a sensitive target, Japanese medaka were used as an aquatic organism model to evaluate the developmental neurotoxicity of 4 organophosphate flame retardants: triphenyl phosphate, tri-n-butyl phosphate, tris(2-butoxyethyl) phosphate, and tris(2-chloroethyl) phosphate (TCEP). The embryo toxicity test showed that organophosphate flame retardant exposure could decrease hatchability, delay time to hatching, increase the occurrence of malformations, reduce body length, and slow heart rate. Regarding locomotor behavior, exposure to the tested organophosphate flame retardants (except TCEP) for 96 h resulted in hypoactivity for medaka larvae in both the free-swimming and the dark-to-light photoperiod stimulation test. Changes of acetylcholinesterase activity and transcriptional responses of genes related to the nervous system likely provide a reasonable explanation for the neurobehavioral disruption. Overall, the present study clearly demonstrates the developmental neurotoxicity of various organophosphate flame retardants with very different potency and contribute to the determination of which organophosphate flame retardants are appropriate substitutes, as well as the consideration of whether regulations are reasonable and required. Environ Toxicol Chem 2016;35:2931-2940. © 2016 SETAC. © 2016 SETAC.

  1. 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 ...

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

    PubMed Central

    Kitambi, Satish S.; Malicki, Jarema J.

    2010-01-01

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

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

    PubMed

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

    2012-06-01

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

  4. 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...

  5. A free calcium wave traverses the activating egg of the medaka, Oryzias latipes

    PubMed Central

    Gilkey, J. C.; Jaffe, L. F.; Ridgway, E. B.; Reynolds, G. T.

    1978-01-01

    Aequorin-injected eggs of the medaka (a fresh water fish) show an explosive rise in free calcium during fertilization, which is followed by a slow return to the resting level. Image intensification techniques now show a spreading wave of high free calcium during fertilization. The wave starts at the animal pole (where the sperm enters) and then traverses the egg as a shallow, roughly 20 degrees-wide band which vanishes at the antipode some minutes later. The peak free calcium concentration within this moving band is estimated to be about 30 microM (perhaps 100-1,000 times the resting level). Eggs activated by ionophore A23187 may show multiple initiation sites. The resulting multiple waves never spread through each other; rather, they fuse upon meeting so as to form spreading waves of compound origin. The fertilization wave is nearly independent of extracellular calcium because it is only slightly slowed (by perhaps 15%) in a medium containing 5 mM ethylene glycol-bis[beta-aminoethyl ether]N,N'-tetraacetic acid (EGTA) and no deliberately added calcium. It is also independent of the large cortical vesicles, which may be centrifugally displaced. Normally, however, it distinctly precedes the well-known wave of cortical vesicle exocytosis. We conclude that the fertilization wave in the medaka egg is propagated by calcium-stimulated calcium release, primarily from some internal sources other than the large cortical vesicles. A comparison of the characteristics of the exocytotic wave in the medaka with that in other eggs, particularly in echinoderm eggs, suggests that such a propagated calcium wave is a general feature of egg activation. PMID:10605450

  6. Molecular cloning and biochemical characterization of medaka (Oryzias latipes) lysosomal neu4 sialidase.

    PubMed

    Shiozaki, Kazuhiro; Ryuzono, Sena; Matsushita, Naoto; Ikeda, Asami; Takeshita, Kazuki; Chigwechokha, Petros Kingstone; Komatsu, Masaharu; Miyagi, Taeko

    2014-10-01

    Glycoconjugates are known to be involved in many physiological events in vertebrates. Sialidase is one of the glycosidases, which removes sialic acid from glycoconjugates. In mammals, the properties and physiological functions of sialidases have been investigated, while there is little understanding of fish sialidase. Here, to investigate the significance of fish neu4 sialidase, neu4 gene was cloned from medaka brain mRNA and identified. Sialidase-specific motifs (GPG, YRVP and Asp-Box) were well conserved in the medaka neu4 polypeptide. Optimal pH of medaka neu4 sialidase was 4.6, but its activity was sustained even at neutral and weak alkaline pH. The neu4 considerably cleaved sialic acid from 4-methylumbelliferyl-N-acetyl-α-D-neuraminic acid and sialyllactose, but not from ganglioside and fetuin, which are good substrates for human NEU4. neu4 activity was mostly detected in mitochondria/lysosome fraction after biochemical fractionation, and indirect immunofluorescence assays revealed neu4 localization in lysosome in neu4 overexpressed cells. Next, developmental change in medaka neu4 and other sialidase mRNA levels were estimated by real-time PCR. Each sialidases showed different expression patterns in embryonic development: neu4 was up-regulated at late developmental stage in embryo, and neu3a mRNA level was quite high in 0.5 dpf. On the other hand, neu3b expression was drastically increased after hatching, suggesting that each sialidase may play a different role in embryonic development.

  7. 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.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2017-01-01

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

  10. 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...

  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. 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...

  13. Serum vitellogenin levels and reproductive impairment of male Japanese Medaka (Oryzias latipes) exposed to 4-tert-octylphenol.

    PubMed Central

    Gronen, S; Denslow, N; Manning, S; Barnes, S; Barnes, D; Brouwer, M

    1999-01-01

    The induction of synthesis of the "female" yolk precursor protein vitellogenin (VTG) in male fish by estrogenic chemicals in the environment has been demonstrated in many recent reports. However, little is known about the organismal and biological significance of this phenomenon. To examine the relationship between VTG production in male fish and reproductive impairment, adult male medaka were exposed to 4-tert-octylphenol (OP), a known environmental estrogen, in concentrations ranging from 20 to 230 ppb for 21 days, under flow-through conditions. Following exposure, male fish were mated, in the absence of OP, with unexposed females. Breeding groups composed of exposed males and control females produced about 50% fewer eggs than control groups. VTG levels in serum of male fish increased with increasing OP exposure concentration and decreased after OP exposure was discontinued. Nevertheless, significant correlations (p<0.01) were observed between VTG levels in exposed male fish and 1) OP exposure concentrations, 2) percent of fertilized eggs, and 3) survival of embryos. OP-induced VTG synthesis and reproductive impairment appear to be closely linked phenomena. Histological examination indicated spermatogenesis in OP-exposed fish was inhibited, and some exposed fish had oocytes in their testes. Finally, OP caused a significant increase in the number of abnormally developing embryos, suggesting that OP may be genotoxic as well as estrogenic. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10210694

  14. Effects of metolachlor on transcription of thyroid system-related genes in juvenile and adult Japanese medaka (Oryzias latipes).

    PubMed

    Jin, Yuanxiang; Chen, Rujia; Wang, Linggang; Liu, Jingwen; Yang, Yuefeng; Zhou, Cheng; Liu, Weiping; Fu, Zhengwei

    2011-02-01

    Metolachlor (MT) is one of the most important pesticides applied to corn and other crops for controlling broadleaf and grass weeds. However, the effects of MT on the thyroid system in fish remain to be elucidated. In the present experiment, transcription of genes related to the thyroid system, including thyrotropin releasing hormone (Trh), deiodinase 2 (Dio2), thyroid hormone receptor α (Thrα), and thyroid hormone receptor β (Thrβ), were induced by MT in a sex-, developmental stage-, and tissue- specific manner when medaka were exposed to various concentrations of MT for 14 days. The transcriptional levels of the genes were only significantly altered in both juvenile and adult female medaka in response to MT exposure. And the lowest concentrations able to significantly induce transcription of the selected genes were 10 and 100 μg/L in juvenile and adult female medaka, respectively. In adult female medaka, a significant up-regulation of these genes was detected only in the brain, with little or no effect in the liver. Furthermore, MT-induced (100 μg/L) transcription of thyroid system-related genes was enhanced significantly in male juvenile medaka in the presence of estrogen (E2) (50 and 100 ng/L). Moreover, the mRNA levels of Thrα and Thrβ in males increase with the combined treatments of 100 μg/L MT and 100 ng/L E2. Dio2 increased when exposed to 100 μg/L MT and 50 or 100 ng/L E2. The information obtained in the present study suggests that MT has the potential to influence several steps of the hypothalamus-pituitary-thyroid (HPT) axis homeostasis and to disrupt the thyroid system in medaka. Copyright © 2010 Elsevier Inc. All rights reserved.

  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. Differential GFP expression patterns induced by different heavy metals in Tg(hsp70:gfp) transgenic medaka (Oryzias latipes).

    PubMed

    Ng, Grace Hwee Boon; Xu, Hongyan; Pi, Na; Kelly, Barry C; Gong, Zhiyuan

    2015-06-01

    Heat shock protein 70 (Hsp70) is one of the most widely used biomarker for monitoring environment perturbations in biological systems. To facilitate the analysis of hsp70 expression as a biomarker, we generated a Tg(hsp70:gfp) transgenic medaka line in which green fluorescence protein (GFP) reporter gene was driven by the medaka hsp70 promoter. Here, we characterized Tg(hsp70:gfp) medaka for inducible GFP expression by seven environment-relevant heavy metals, including mercury, arsenic, lead, cadmium, copper, chromium, and zinc. We found that four of them (mercury, arsenic, lead, and cadmium) induced GFP expression in multiple and different organs. In general, the liver, kidney, gut, and skin are among the most frequent organs to show induced GFP expression. In contrast, no detectable GFP induction was observed to copper, chromium, or zinc, indicating that the transgenic line was not responsive to all heavy metals. RT-qPCR determination of hsp70 mRNA showed similar induction and non-induction by these metals, which also correlated with the levels of metal uptake in medaka exposed to these metals. Our observations suggested that these heavy metals have different mechanisms of toxicity and/or differential bioaccumulation in various organs; different patterns of GFP expression induced by different metals may be used to determine or exclude metals in water samples tested. Furthermore, we also tested several non-metal toxicants such as bisphenol A, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 4-introphenol, and lindane; none of them induced significant GFP expression in Tg(hsp70:gfp) medaka, further suggesting that the inducibility of Tg(hsp70:gfp) for GFP expression is specific to a subset of heavy metals.

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

    PubMed

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

    2014-01-01

    Here we proposed a battery of non-invasive biomarkers and a histological survey to examine physiological/anatomical features in embryos, eleutheroembryos (13 days post-fertilization, dpf), and larvae (28-42 dpf) of medaka to investigate the effects of embryonic exposure to propylparaben (PrP). Concentrations <1000 μg PrP/L didn't exert early or late toxic effects. However, survivorship was affected at 4000 μg/L in eleutheroembryos and at ≥1000 μg/L in larvae. Histological alterations were found in 37.5% of eleutheroembryos exposed to 4000 μg PrP/L. Morphometric analysis of the gallbladder revealed significant dilation at ≥400 μg/L throughout embryo development. Ethoxyresorufin-O-deethylase (EROD), as indicator of cytochrome P4501A activity, didn't reveal induction/inhibition although its combination with a P4501A agonist (i.e. β-naphthoflavone) resulted in a synergic EROD response. Results suggest a low toxicity of PrP for fish and support the use of fish embryos and eleutheroembryos as alternatives of in vivo biomarkers indicative of exposure/toxicity.

  18. Genome-wide identification of novel ovarian-predominant miRNAs: new insights from the medaka (Oryzias latipes)

    PubMed Central

    Bouchareb, Amine; Le Cam, Aurélie; Montfort, Jérôme; Gay, Stéphanie; Nguyen, Thaovi; Bobe, Julien; Thermes, Violette

    2017-01-01

    MicroRNAs (miRNAs) are small, highly conserved non-coding RNAs that play important roles in the regulation of many physiological processes. However, the role of miRNAs in vertebrate oocyte formation (i.e., oogenesis) remains poorly investigated. To gain new insights into the roles of miRNAs in oogenesis, we searched for ovarian-predominant miRNAs. Using a microarray displaying 3,800 distinct miRNAs originating from different vertebrate species, we identified 66 miRNAs that are expressed predominantly in the ovary. Of the miRNAs exhibiting the highest overabundance in the ovary, 20 were selected for further analysis. Using a combination of QPCR and in silico analyses, we identified 8 novel miRNAs that are predominantly expressed in the ovary, including 2 miRNAs (miR-4785 and miR-6352) that exhibit strict ovarian expression. Of these 8 miRNAs, 7 were previously uncharacterized in fish. The strict ovarian expression of miR-4785 and miR-6352 suggests an important role in oogenesis and/or early development, possibly involving a maternal effect. Together, these results indicate that, similar to protein-coding genes, a significant number of ovarian-predominant miRNA genes are found in fish. PMID:28071684

  19. 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...

  20. 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). Copyright © 2016 Elsevier B.V. All rights reserved.

  1. 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...

  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. 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.

  4. Novel method for analysis of allele specific expression in triploid Oryzias latipes reveals consistent pattern of allele exclusion.

    PubMed

    Garcia, Tzintzuni I; Matos, Isa; Shen, Yingjia; Pabuwal, Vagmita; Coelho, Maria Manuela; Wakamatsu, Yuko; Schartl, Manfred; Walter, Ronald B

    2014-01-01

    Assessing allele-specific gene expression (ASE) on a large scale continues to be a technically challenging problem. Certain biological phenomena, such as X chromosome inactivation and parental imprinting, affect ASE most drastically by completely shutting down the expression of a whole set of alleles. Other more subtle effects on ASE are likely to be much more complex and dependent on the genetic environment and are perhaps more important to understand since they may be responsible for a significant amount of biological diversity. Tools to assess ASE in a diploid biological system are becoming more reliable. Non-diploid systems are, however, not uncommon. In humans full or partial polyploid states are regularly found in both healthy (meiotic cells, polynucleated cell types) and diseased tissues (trisomies, non-disjunction events, cancerous tissues). In this work we have studied ASE in the medaka fish model system. We have developed a method for determining ASE in polyploid organisms from RNAseq data and we have implemented this method in a software tool set. As a biological model system we have used nuclear transplantation to experimentally produce artificial triploid medaka composed of three different haplomes. We measured ASE in RNA isolated from the livers of two adult, triploid medaka fish that showed a high degree of similarity. The majority of genes examined (82%) shared expression more or less evenly among the three alleles in both triploids. The rest of the genes (18%) displayed a wide range of ASE levels. Interestingly the majority of genes (78%) displayed generally consistent ASE levels in both triploid individuals. A large contingent of these genes had the same allele entirely suppressed in both triploids. When viewed in a chromosomal context, it is revealed that these genes are from large sections of 4 chromosomes and may be indicative of some broad scale suppression of gene expression.

  5. 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.

  6. 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.

  7. 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

    2016-01-25

    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.

  8. Proteomic and phosphoproteomic analysis of cellular responses in medaka fish (Oryzias latipes) following oral gavage with microcystin-LR.

    PubMed

    Mezhoud, K; Bauchet, A L; Château-Joubert, S; Praseuth, D; Marie, A; François, J C; Fontaine, J J; Jaeg, J P; Cravedi, J P; Puiseux-Dao, S; Edery, M

    2008-06-15

    Chronic and subchronic toxicity resulting from exposure to microcystins (MCs) receives increasing attention due to the risk of bioaccumulation of these toxins by aquatic animals, including fish. The mechanisms of action of MCs that target the liver, involve modifications of protein phosphorylation resulting from phosphatases 1 and 2A inhibition. Therefore, studying phosphoprotein modifications by using a specific phosphoprotein stain Pro-Q Diamond in fish liver contaminated with MC-leucine-arginine (MC-LR), the most toxic MC, should help dissecting disturbed signaling and metabolic networks. We have recently used this technology to identify several proteins that are modulated either in expression or phosphorylation in the liver of medaka following short-term exposure to MC-LR by balneation. In the present study, we have decided to use an alternative way of introducing the toxin into fish; that is by gavage (force-feeding). This was first achieved using tritiated MC-LR and allowed us to quantify the quantity of toxin incorporated into fish and to demonstrate that the toxin is mainly accumulated in liver. Afterwards a proteomics study limited to liver cytosolic proteins of contaminated animals showed that several proteins were up or down regulated either in quantity or in phosphorylation or both. Some of them had been previously detected as modified in balneation experiments but new molecules were identified as involved in signal transduction pathways activated by the toxin. In addition, in the conditions used (5 microg toxin/g body weight) anatomopathological studies supported a process of apoptonecrosis established after 24h, which was suggested to proceed by the evolution of some of the proteins after 2h contamination.

  9. 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...

  10. 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...

  11. 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...

  12. VARIATIONS OF LIGHT AND TEMPERATURE REGIMES AND RESULTING EFFECTS ON REPRODUCTIVE PARAMETERS IN 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...

  13. 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...

  14. The effect of chlorination of estrogenic chemicals on the level of serum vitellogenin of Japanese medaka (Oryzias latipes).

    PubMed

    Tabata, A; Miyamoto, N; Ohnishi, Y; Itoh, M; Yamada, T; Kamei, T; Magara, Y

    2003-01-01

    Mature male medaka were continually exposed to four chemicals, p-n-nonylphenol (p-n-NP), nonylphenol (p-NP), bisphenol-A (BPA) and 17beta-estradiol (E2) to evaluate their estrogenic activities in the laboratory. In order to understand the effect of the chlorination that is applied widely in water and wastewater treatment, the above chemicals were chlorinated and then exposed to mature male medaka. Furthermore, in the case of vitellogenin, a is a female specific protein induced by the exposure to test waters containing the above chemicals after 5 weeks, medaka was returned to uncontaminated tap water to determine whether male medaka have a self recovery function from the effect of estrogenic chemicals. Much greater vitellogenin compared to the background levels were induced in the male medaka by separate exposure to 100 microg/L of p-NP, 1,000 microg/L of BPA and 0.05 microg/L of E2. The levels of vitellogenin increased with increasing exposure periods. The relative potencies of these chemicals descended in the order of E2>p-NP>BPA. Vitellogenin levels inducible by these chemicals were drastically reduced as a result of the chlorination for 24 hours. However, a moderate increase in hepatocyte somatic index (HSI) meant the hepatic fatness was observed as a result of chlorination. It is not clear at this stage whether or not the formation of chlorination byproducts is responsible for this moderate increase in HSI. The vitellogenin concentration of male medaka exposed to chemicals for 5 weeks decreased gradually after return to the uncontaminated water. However, the vitellogenin concentration did not return to the initial normal levels even after 5 weeks. A clear relationship between the serum vitellogenin concentration and the hepatic vitellogenin concentration was also found. Since quantitative analytical procedures for hepatic vitellogenin are easier than those of the serum vitellogenin, measuring the estrogenic effect using the measurement of vitellogenin in liver is recommended.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. EFFECTS OF ETHINYLESTRADIOL ON REPRODUCTION AND ENDOCRINE FUNCTION IN JAPANESE MEDAKA (ORYZIAS LATIPES): II. TRANSGENERATIONAL EXPOSURE. (R827098)

    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...

  1. EFFECTS OF ETHINYLESTRADIOL ON REPRODUCTION AND ENDOCRINE FUNCTION IN JAPANESE MEDAKA (ORYZIAS LATIPES): I. DEVELOPMENTAL EXPOSURE. (R827098)

    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. 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 ...

  3. 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.

  4. 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

  5. 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

  6. 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...

  7. Oral toxicity of extracts of the microcystin-containing cyanobacterium Planktothrix agardhii to the medaka fish (Oryzias latipes).

    PubMed

    Djediat, Chakib; Moyenga, David; Malécot, Mélodie; Comte, Katia; Yéprémian, Claude; Bernard, Cécile; Puiseux-Dao, Simone; Edery, Marc

    2011-07-01

    As previously demonstrated the medaka fish appears to offer a good model for studies of microcystins (MCs) effects. Since cyanobacterial toxins are released with other molecules in the aquatic environment when the producers are dying, in this study, we performed additional experiments in order to compare the described effects obtained with the pure toxin microcystin-LR (MC-LR), among the most toxic MCs, to those induced by complex extracts of an MCs-producer Planktothrix agardhii, strain PMC 75.02 and a natural bloom containing the MCs-producer P. agardhii. The toxicity of these extracts containing several variants of MC was determined in adult medaka treated by gavage. Extracts of an MCs-free strain of P. agardhii (PMC 87.02) were assayed for comparison. Extracts effects were analysed on two tissues, liver and intestine by means of photon and transmission electron microscopy. MC was localized in these tissues by immunocytochemistry. No effect was detectable with extracts of the MCs-free P. agardhii strain. The two MCs-P. agardhii extracts (strain and natural bloom) were able to induce harmful effects in the liver and intestine of the medaka fish in acute intoxication by gavage. In these target organs as shown by toxin immunolocalization, reactions leading to cell disjunction and lysis were observed apparently associated with an immune reaction implying MC containing macrophages. These effects are similar to those previously described with photonic microscopy in medaka treated with pure MC-LR with additional results obtained under the electron microscope. Since no significant effect was detected with the MCs-free (PMC 87.02) extract, we then conclude that MCs, even in complex association with other cyanobacterial components, should be responsible for the toxic effects observed in treated fish.

  8. VARIATIONS OF LIGHT AND TEMPERATURE REGIMES AND RESULTING EFFECTS ON REPRODUCTIVE PARAMETERS IN 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...

  9. 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.

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

    DTIC Science & Technology

    1995-01-10

    tumors, melanoma Actin Skeletal muscle Chromogranin Neuroendocrine cells Myelin associated protein Neurons ULEX europaeus agglutinin I Endothelial...Actin BioGenex + Ulex europaeus agglutinin I Vector Endothelial cell antigen BioGenex ND Lysozyme BioGenex ND S-100 protein BioGenex + MAP-2...antitrypsin Common marker for hepatocellular carcinoma Factor VIII/ UEA - I Markers for endothelial cell differentiation S-100 protein Marker for nerve sheath

  11. 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...

  12. Large-scale analysis of the genes involved in fin regeneration and blastema formation in the medaka, Oryzias latipes.

    PubMed

    Katogi, Rei; Nakatani, Yuki; Shin-i, Tadasu; Kohara, Yuji; Inohaya, Keiji; Kudo, Akira

    2004-07-01

    Medaka is an attractive model to study epimorphic regeneration. The fins have remarkable regenerative capacity and are replaced about 14 days after amputation. The formation of blastema, a mass of undifferentiated cells, is essential for regeneration; however, the molecular mechanisms are incompletely defined. To identify the genes required for fin regeneration, especially for blastema formation, we constructed cDNA libraries from fin regenerates at 3 days postamputation and 10 days postamputation. A total of 16,866 expression sequence tags (ESTs) were sequenced and subjected to BLASTX analysis. The result revealed that about 60% of them showed strong matches to previously identified proteins, and major signaling molecules related to development, including FGF, BMP, Wnt, Notch/Delta, and Ephrin/Eph signaling pathways were isolated. To identify novel genes that showed specific expression during fin regeneration, cDNA microarray was generated based on 2900 independent ESTs from each library which had no sequence similarity to known proteins. We obtained 6 candidate genes associated with blastema formation by gene expression pattern screening in competitive hybridization analyses and in situ hybridization. Olrfe16d23 and olrfe14k04 were expressed only in early regenerating stages when blastema formation was induced. The expression of olrf5n23, which encodes a novel signal peptide, was detected in wound epidermis throughout regeneration. Olrfe23l22, olrfe20n22, and olrfe24i02 were expressed notably in the blastema region. Our study has thus identified the gene expression profiles and some novel candidate genes to facilitate elucidation of the molecular mechanisms of fin regeneration.

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

    PubMed

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

    2016-01-10

    Desialylation in the lysosome is a crucial step for glycoprotein degradation. The abnormality of lysosomal desialylation by NEU1 sialidase is involved in diseases of mammals such as sialidosis and galactosialidosis. Mammalian Neu1 sialidase is also localized at plasma membrane where it regulates several signaling pathways through glycoprotein desialylation. In fish, on the other hand, the mechanism of desialylation in the lysosome and functions of Neu1 sialidase are still unclear. Here, to understand the significance of fish Neu1 sialidase, neu1 gene was cloned from medaka brain and the profiles of its polypeptides were analyzed. Open reading frame of medaka neu1 consisted 1,182 bp and the similarity of its deduced amino acids with human NEU1 was 57%. As this recombinant polypeptide did not show significant sialidase activity, medaka cathepsin A, known in mammals as protective protein activating Neu1, was cloned and then co-expressed with medaka Neu1 to examine whether medaka cathepsin A activates Neu1 activity. As a result, Neu1/cathepsin A showed a drastic increase of sialidase activity toward MU-NANA. Major substrate of medaka Neu1 was 3-sialyllactose and its optimal pH was 4.0. With immunofluorescence analysis, signal of overexpressed medaka Neu1 was found to coincide with Lysotracker signals (organelle marker of lysosome) and co-localized with medaka cathepsin A in fish hepatic Hepa-T1 cells. Furthermore, part of medaka Neu1 was also detected at plasma membrane. Medaka Neu1 possessed signal peptide sequence at N-terminal and incomplete lysosomal targeting sequence at C-terminus. Medaka neu1 gene was ubiquitously expressed in various medaka tissues, and its expression level was significantly higher than other sialidase genes such as neu3a, neu3b and neu4. The present study revealed the profiles of fish Neu1 sialidase and indicated its high conservation with human NEU1 for the first time, suggesting the presence of similar desialylation system in the medaka lysosome to human. Moreover, the present study showed the possibility of medaka as a model animal of human NEU1 sialidase.

  14. 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...

  15. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  18. 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

  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. 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...

  1. 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...

  2. 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.

  3. Effects of Kisspeptin1 on Electrical Activity of an Extrahypothalamic Population of Gonadotropin-Releasing Hormone Neurons in Medaka (Oryzias latipes)

    PubMed Central

    Zhao, Yali; Wayne, Nancy L.

    2012-01-01

    Kisspeptin (product of the kiss1 gene) is the most potent known activator of the hypothalamo-pituitary-gonadal axis. Both kiss1 and the kisspeptin receptor are highly expressed in the hypothalamus of vertebrates, and low doses of kisspeptin have a robust and long-lasting stimulatory effect on the rate of action potential firing of hypophysiotropic gonadotropin releasing hormone-1 (GnRH1) neurons in mice. Fish have multiple populations of GnRH neurons distinguished by their location in the brain and the GnRH gene that they express. GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb are neuromodulatory and do not play a direct role in regulating pituitary-gonadal function. In medaka fish, the electrical activity of TN-GnRH3 neurons is modulated by visual cues from conspecifics, and is thought to act as a transmitter of information from the external environment to the central nervous system. TN-GnRH3 neurons also play a role in sexual motivation and arousal states, making them an important population of neurons to study for understanding coordination of complex behaviors. We investigated the role of kisspeptin in regulating electrical activity of TN-GnRH3 neurons in adult medaka. Using electrophysiology in an intact brain preparation, we show that a relatively brief treatment with 100 nM of kisspeptin had a long-lasting stimulatory effect on the electrical activity of an extrahypothalamic population of GnRH neurons. Dose-response analysis suggests a relatively narrow activational range of this neuropeptide. Further, blocking action potential firing with tetrodotoxin and blocking synaptic transmission with a low Ca2+/high Mg2+ solution inhibited the stimulatory action of kisspeptin on electrical activity, indicating that kisspeptin is acting indirectly through synaptic regulation to excite TN-GnRH3 neurons. Our findings provide a new perspective on kisspeptin's broader functions within the central nervous system, through its regulation of an extrahypothalamic population of GnRH neurons involved in multiple neuromodulatory functions. PMID:22649563

  4. 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

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

    2013-01-01

    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. 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. 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.

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

    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

  6. 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...

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

    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...

  8. Microcystin-LR and embryo-larval development of medaka fish, Oryzias latipes. I. Effects on the digestive tract and associated systems.

    PubMed

    Huynh-Delerme, Céline; Edery, Marc; Huet, Hélène; Puiseux-Dao, Simone; Bernard, Cécile; Fontaine, Jean-Jacques; Crespeau, François; de Luze, Amaury

    2005-07-01

    The cyanobacterial hepatotoxin microcystin-LR (MC-LR) is a specific potent PP1 and PP2A protein phosphatase inhibitor. In view to obtain an integrated whole-body, understanding of the key target organs of MC-LR subsequent to embryonic exposure on the anatomy of medaka fish hatchlings, embryos at stage 19 were microinjected with a sublethal dose of MC-LR corresponding to 0.2 pg/vitellus. MC-LR-induced histo-pathological modifications of the alimentary system (i.e. digestive tract, pancreas, liver) were analysed in newly hatched embryos. Our data are indicative of an MC-LR-induced inhibition of both yolk sac resorption and gas concentrating swimbladder expansion. In contrast to control hatchlings, (i) no mucus-secreting cells in the oesophagus, (ii) a decreased folding of the stomach and intestine, (iii) a clear reduction in size of the exocrine pancreas associated with a destructuration of acinar units, and (iv) a strong decrease in the mass and size of the liver were observed in MC-LR treated embryos. Furthermore, as an indication of MC-LR-induced hepatic glycogen store depletion, unstained cytoplasmic areas present in control hatchling hepatocytes, were fully absent in all liver examined in treated embryos. Finally, as a general observation in MC-LR-treated embryos, our data clearly indicated terminal differentiation disorders in all organs associated with the digestive tract.

  9. 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...

  10. 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...

  11. 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.

  12. Risks of single-walled carbon nanotubes acting as contaminants-carriers: potential release of phenanthrene in Japanese medaka (Oryzias latipes).

    PubMed

    Su, Yu; Yan, Xiaomin; Pu, Yubing; Xiao, Feng; Wang, Dongsheng; Yang, Min

    2013-05-07

    The performance of carbon nanotubes (CNTs) acting as contaminants-carriers in vivo is critical for understanding the environmental risks of CNTs. In this study, the whole-body accumulation and tissue distribution of phenanthrene in Japanese medaka was examined in the presence of single-walled carbon nanotubes (SWCNTs) and the potential release of phenanthrene was investigated from two types of SWCNTs suspensions that differed in surface charge and stability. The results showed that the coexistence of SWCNTs facilitated the accumulation of phenanthrene in the digestive track of fish and therefore enhanced the whole-body phenanthrene concentration by 2.1 fold after exposure for 72 h. Meanwhile, 6.4-48 and 20-34 times higher phenanthrene concentrations were measured in the liver and brain of fish exposure to the two mixtures, respectively, when comparing with the phenanthrene alone treatment with equal concentration of soluble phenanthrene. The extra phenanthrene was from the SWCNTs-associated phenanthrene that accumulated in the digestive track indicating the release of phenanthrene from SWCNTs did occur in fish. Moreover, the neutrally charged SWCNTs showed different agglomeration behaviors from the negatively charged SWCNTs, which could affect the accumulation of SWCNTs in the digestive track of fish and subsequently influence the retention of phenanthrene associated with the carbon nanotubes.

  13. Cross-generational effects of parental low dose BPA exposure on the Gonadotropin-Releasing Hormone3 system and larval behavior in medaka (Oryzias latipes).

    PubMed

    Inagaki, T; Smith, N L; Sherva, K M; Ramakrishnan, S

    2016-12-01

    Growing evidence indicates that chronic exposure to Bisphenol A (BPA) may disrupt normal brain function and behavior mediated by gonadotropin-releasing hormone (GnRH) pathways. Previous studies have shown that low dose BPA (200ng/ml) exposure during embryogenesis altered development of extra-hypothalamic GnRH3 systems and non-reproductive locomotor behavior in medaka. Effects of parental low-dose BPA exposure on the development of GnRH3 systems and locomotor behavior of offspring are not well known. This study examines whether the neurophysiological and behavioral effects of BPA in parents (F0 generation) are carried over to their offspring (F1 generation) using stable transgenic medaka embryos/larvae with GnRH3 neurons tagged with green fluorescent protein (GFP). Parental fish were exposed to BPA (200ng/ml) for either life-long or different developmental time windows. Fertilized F1 eggs were collected and raised in egg/fish water with no environmental exposure to BPA. All experiments were performed on F1 embryos/larvae, which were grouped based on the following parental (F0) BPA exposure conditions - (i) Group 1 (G1): through life; (ii) G2: during embryogenesis and early larval development [1-14days post fertilization (dpf)]; (iii) G3: during neurogenesis (1-5dpf); and (iv) G4: during sex differentiation (5-14dpf). Embryos from unexposed vehicle treated parents served as controls (G0). G1 embryos showed significantly reduced survival rates and delayed hatching time compared to other groups, while G4 embryos hatched significantly earlier than all other groups. At 3 dpf, the GnRH3-GFP intensity was increased by 47% in G3 embryos and decreased in G4 embryos by 59% compared to controls. At 4dpf, G1 fish showed 42% increased intensity, while GFP intensity was reduced by 44% in G3 subjects. In addition, the mean brain size of G1, G3 and G4 embryos were smaller than that of control at 4dpf. At 20dpf, all larvae from BPA-treated parents showed significantly decreased total movement (distance covered) compared with controls, with G2 and G3 fish showing reduced velocity of movement. While at 20 dpf no group differences were seen in the soma diameter of GnRH3-GFP neurons, a 34% decrease in SV2 expression, a marker for synaptic transmission, in G1 larvae was observed. These data suggest that parental BPA exposure during critical windows of embryonic development or chronic treatment affects next-generation offspring both in embryonic and larval brain development as well as larval behavior.

  14. 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...

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

    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...

  17. The effect of bisphenol A and chlorinated derivatives of bisphenol A on the level of serum vitellogenin in Japanese medaka (Oryzias latipes).

    PubMed

    Tabata, A; Watanabe, N; Yamamoto, I; Ohnishi, Y; Itoh, M; Kamei, T; Magara, Y; Terao, Y

    2004-01-01

    2,2-bis (4-hydroxyphenyl) propane or Bisphenol A (BPA), has been reported to behave as an endocrine disrupter below acute toxic levels, and is widely present in the water environment. Although BPA is easily chlorinated, very little is reported on the effect of chlorinated BPA to the aquatic organisms. In this study, the estrogenic activities of BPA and its chlorinated derivatives were evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka. In addition, the effect of sodium hypochlorite on the decomposition of BPA was tested. The relative potencies of estrogenic activities of chlorinated BPA descended in the order 3,3'-diCIBPA>BPA> or =3-CIBPA>3,3',5-triCIBPA, and no estrogenic activity was observed in 3,3',5,5'-tetraCIBPA. Lowest Observed Effect Concentration (LOEC) and No Observed Effect Concentration (NOEC) for both 3-CIBPA and 3,3'-diCIBPA were 500 microg/L and 200 microg/L, respectively. LOEC for 3,3',5-triCIBPA was >500 microg/L. When BPA was reacted with sodium hypochlorite (24 hours; residual chlorine at 1 ppm), however, complete decomposition of BPA and its chlorinated derivatives was observed. The decrease in BPA and its chlorinated derivatives paralleled the decrease in estrogenic potency evaluated by the induction of vitellogenin (VTG) in the serum of mature male Japanese medaka.

  18. 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.

  19. IDENTIFICATION CHARACTERIZATION AND ONTOGENY OF A SECOND CYTOCHROME P450 3A GENE 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...

  20. 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...

  1. 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...

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

    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. Gamma-ray irradiation promotes premature meiosis of spontaneously differentiating testis–ova in the testis of p53-deficient medaka (Oryzias latipes)

    PubMed Central

    Yasuda, T; Oda, S; Li, Z; Kimori, Y; Kamei, Y; Ishikawa, T; Todo, T; Mitani, H

    2012-01-01

    In this study, the roles of p53 in impaired spermatogenic male germ cells of p53-deficient medaka were investigated by analyzing histological changes, and gene expressions of 42Sp50, Oct 4 and vitellogenin (VTG2) by RT-PCR or in situ hybridization in the testes. We found that a small number of oocyte-like cells (testis–ova) differentiated spontaneously in the cysts of type A and early type B spermatogonia in the p53-deficient testes, in contrast to the wild-type (wt) testes in which testis–ova were never found. Furthermore, ionizing radiation (IR) irradiation increased the number of testis–ova in p53-deficient testes, increased testis–ova size and proceeded up to the zygotene or pachytene stages of premature meiosis within 14 days after irradiation. However, 28 days after irradiation, almost all the testis–ova were eliminated presumably by p53-independent apoptosis, and spermatogenesis was restored completely. In the wt testis, IR never induced testis–ova differentiation. This is the first study to demonstrate the pivotal role of the p53 gene in the elimination of spontaneous testis–ova in testes, and that p53 is not indispensable for the restoration of spermatogenesis in the impaired testes in which cell cycle regulation is disturbed by IR irradiation. PMID:23034330

  4. Whole brain-pituitary in vitro preparation of the transgenic medaka (Oryzias latipes) as a tool for analyzing the differential regulatory mechanisms of LH and FSH release.

    PubMed

    Karigo, Tomomi; Aikawa, Masato; Kondo, Chika; Abe, Hideki; Kanda, Shinji; Oka, Yoshitaka

    2014-02-01

    Two types of gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), are important pituitary hormones for sexual maturation and reproduction, and both of them are centrally regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. In mammals, these two gonadotropins are secreted from a single type of gonadotrope. The mechanisms of differential regulation by GnRH of the release of two types of gonadotropins with different secretory profiles are still unknown. In teleosts, however, LH and FSH are secreted from separate cellular populations, unlike in mammals. This feature makes them useful for studying the regulatory mechanisms of LH and FSH secretions independently. Here, we generated transgenic medaka lines that express Ca(2+) indicator protein, inverse-pericam, specifically in the LH or FSH cells. We performed cell-type-specific Ca(2+) imaging of LH and FSH cells, respectively, using the whole brain-pituitary preparations of these transgenic fish in which all neural circuits and GnRH neuronal projection to the pituitary are kept intact. LH and FSH cells showed different Ca(2+) responses to GnRH. The results suggest differential regulation mechanisms for LH and FSH release by GnRH. Moreover, we also succeeded in detecting the effect on LH cells of endogenous GnRH peptide, which was released by electrical stimulation of the axons of GnRH1 neurons. Thus, our newly developed experimental model system using the whole brain-pituitary in vitro preparation of the transgenic medaka is a powerful tool for analyzing the differential regulatory mechanisms of the release of LH and FSH by multisynaptic neural inputs to the pituitary.

  5. DETERMINING THE SENSITIVE DEVELOPMENTAL STAGES OF INTERSEX INDUCTION IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO 17 B-ESTRADIOL OR TESTOSTERONE. (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...

  6. DETERMINING THE SENSITIVE DEVELOPMENTAL STAGES OF INTERSEX INDUCTION IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO 17 BETA-ESTRADIOL OR TESTOSTERONE. (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...

  7. 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...

  8. DETERMINING THE SENSITIVE DEVELOPMENTAL STAGES OF INTERSEX INDUCTION IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO 17 BETA-ESTRADIOL OR TESTOSTERONE. (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...

  9. DETERMINING THE SENSITIVE DEVELOPMENTAL STAGES OF INTERSEX INDUCTION IN MEDAKA (ORYZIAS LATIPES) EXPOSED TO 17 B-ESTRADIOL OR TESTOSTERONE. (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...

  10. 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...

  11. Gamma-ray irradiation promotes premature meiosis of spontaneously differentiating testis-ova in the testis of p53-deficient medaka (Oryzias latipes).

    PubMed

    Yasuda, T; Oda, S; Li, Z; Kimori, Y; Kamei, Y; Ishikawa, T; Todo, T; Mitani, H

    2012-10-04

    In this study, the roles of p53 in impaired spermatogenic male germ cells of p53-deficient medaka were investigated by analyzing histological changes, and gene expressions of 42Sp50, Oct 4 and vitellogenin (VTG2) by RT-PCR or in situ hybridization in the testes. We found that a small number of oocyte-like cells (testis-ova) differentiated spontaneously in the cysts of type A and early type B spermatogonia in the p53-deficient testes, in contrast to the wild-type (wt) testes in which testis-ova were never found. Furthermore, ionizing radiation (IR) irradiation increased the number of testis-ova in p53-deficient testes, increased testis-ova size and proceeded up to the zygotene or pachytene stages of premature meiosis within 14 days after irradiation. However, 28 days after irradiation, almost all the testis-ova were eliminated presumably by p53-independent apoptosis, and spermatogenesis was restored completely. In the wt testis, IR never induced testis-ova differentiation. This is the first study to demonstrate the pivotal role of the p53 gene in the elimination of spontaneous testis-ova in testes, and that p53 is not indispensable for the restoration of spermatogenesis in the impaired testes in which cell cycle regulation is disturbed by IR irradiation.

  12. Polycystic Kidney Disease in the Medaka (Oryzias latipes) pc Mutant Caused by a Mutation in the Gli-Similar3 (glis3) Gene

    PubMed Central

    Hashimoto, Hisashi; Miyamoto, Rieko; Watanabe, Naoki; Shiba, Dai; Ozato, Kenjiro; Inoue, Chikako; Kubo, Yuko; Koga, Akihiko; Jindo, Tomoko; Narita, Takanori; Naruse, Kiyoshi; Ohishi, Kazuko; Nogata, Keiko; Shin-I, Tadasu; Asakawa, Shuichi; Shimizu, Nobuyoshi; Miyamoto, Tomotsune; Mochizuki, Toshio; Yokoyama, Takahiko; Hori, Hiroshi; Takeda, Hiroyuki; Kohara, Yuji; Wakamatsu, Yuko

    2009-01-01

    Polycystic kidney disease (PKD) is a common hereditary disease in humans. Recent studies have shown an increasing number of ciliary genes that are involved in the pathogenesis of PKD. In this study, the Gli-similar3 (glis3) gene was identified as the causal gene of the medaka pc mutant, a model of PKD. In the pc mutant, a transposon was found to be inserted into the fourth intron of the pc/glis3 gene, causing aberrant splicing of the pc/glis3 mRNA and thus a putatively truncated protein with a defective zinc finger domain. pc/glis3 mRNA is expressed in the epithelial cells of the renal tubules and ducts of the pronephros and mesonephros, and also in the pancreas. Antisense oligonucleotide-mediated knockdown of pc/glis3 resulted in cyst formation in the pronephric tubules of medaka fry. Although three other glis family members, glis1a, glis1b and glis2, were found in the medaka genome, none were expressed in the embryonic or larval kidney. In the pc mutant, the urine flow rate in the pronephros was significantly reduced, which was considered to be a direct cause of renal cyst formation. The cilia on the surface of the renal tubular epithelium were significantly shorter in the pc mutant than in wild-type, suggesting that shortened cilia resulted in a decrease in driving force and, in turn, a reduction in urine flow rate. Most importantly, EGFP-tagged pc/glis3 protein localized in primary cilia as well as in the nucleus when expressed in mouse renal epithelial cells, indicating a strong connection between pc/glis3 and ciliary function. Unlike human patients with GLIS3 mutations, the medaka pc mutant shows none of the symptoms of a pancreatic phenotype, such as impaired insulin expression and/or diabetes, suggesting that the pc mutant may be suitable for use as a kidney-specific model for human GLIS3 patients. PMID:19609364

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

    PubMed

    Zhao, Yali; Wayne, Nancy L

    2012-01-01

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

  14. CHARACTERISTICS AND TOXICITY OF THE DRINKING WATER DISINFECTION BY-PRODUCT 3-CHLORO-4(DICHLOROMETHYL)-5-HYDROXY-2[5H]-FURANONE (MX) TO MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    The compound 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, also known as MX, is a by-product of wood pulp manufacture and a contaminant of chlorinated drinking and sewage water. MX has recently been shown to be carcinogenic to rodents. However, no data exist for its effec...

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

    PubMed

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

    2017-07-21

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    Treesearch

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

    2012-01-01

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

  18. Toxicity of manganese metallodrugs toward Danio rerio.

    PubMed

    Arndt, Anderson; Borella, Maria Inês; Espósito, Breno Pannia

    2014-02-01

    Manganese is an essential metal which can be neurotoxic in some instances. As Mn-based metallodrugs are ever more prevalent in clinical practice, concern regarding the toxic effects of Mn discharges to water bodies on the biota prompted us to study the physicochemical parameters of these complexes and to assess their acute toxicity toward adult Danio rerio individuals, particularly in terms of brain tissue damage. Our results show that the Mn(III)-salen acetate complex EUK108 is toxic, which can be rationalized in terms of its lipophilicity, stability and redox activity.

  19. Danio rerio: Small Fish Making a Big Splash in Leukemia.

    PubMed

    Squiban, Barbara; Frazer, J Kimble

    2014-06-01

    Zebrafish (Danio rerio) are widely used for developmental biology studies. In the past decade, D. rerio have become an important oncology model as well. Leukemia is one type of cancer where zebrafish are particularly valuable. As vertebrates, fish have great anatomic and biologic similarity to humans, including their hematopoietic and immune systems. As an experimental platform, D. rerio offer many advantages that mammalian models lack. These include their ease of genetic manipulation, capacity for imaging, and suitability for large-scale phenotypic and drug screens. In this review, we present examples of these strategies and others to illustrate how zebrafish have been and can be used to study leukemia. Besides appraising the techniques researchers apply and introducing the leukemia models they have created, we also highlight recent and exciting discoveries made using D. rerio with an eye to where the field is likely headed.

  20. Danio rerio: Small Fish Making a Big Splash in Leukemia

    PubMed Central

    Squiban, Barbara; Frazer, J. Kimble

    2015-01-01

    Zebrafish (Danio rerio) are widely used for developmental biology studies. In the past decade, D. rerio have become an important oncology model as well. Leukemia is one type of cancer where zebrafish are particularly valuable. As vertebrates, fish have great anatomic and biologic similarity to humans, including their hematopoietic and immune systems. As an experimental platform, D. rerio offer many advantages that mammalian models lack. These include their ease of genetic manipulation, capacity for imaging, and suitability for large-scale phenotypic and drug screens. In this review, we present examples of these strategies and others to illustrate how zebrafish have been and can be used to study leukemia. Besides appraising the techniques researchers apply and introducing the leukemia models they have created, we also highlight recent and exciting discoveries made using D. rerio with an eye to where the field is likely headed. PMID:26269780

  1. European network using fish as osteoporosis research models (ENFORM)

    NASA Astrophysics Data System (ADS)

    Goerlich, R.; Renn, J.; Alestrom, P.; Nouizadeh-Lillabadi, R.; Schartl, M.; Winkler, C.; Muller, M.; Midtyng, P. J.; Eberius, M.; Slenzka, K.

    2005-08-01

    Osteoporosis, characterised by loss of bone density, is one of the most important bone diseases of humans worldwide. It causes problems in post-menopausal women, in astronauts during long-term spaceflights and in industrial animal production. Bone alterations leading to osteoporosis are well-documented at the cellular level, but the underlying molecular events are still poorly understood and most of our knowledge is derived from in vitro studies using cell culture systems. Recent findings indicate a remarkable conservation of the key regulators of bone development and homeostasis between mammals and fish. Medaka (Oryzias latipes) and zebrafish (Danio rerio) offer experimental advantages that can be exploited for bone research.

  2. 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

  3. 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

    2016-09-01

    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.

  4. Production of Androgenetic Zebrafish (Danio Rerio)

    PubMed Central

    Corley-Smith, G. E.; Lim, C. J.; Brandhorst, B. P.

    1996-01-01

    To help investigate the evolutionary origin of the imprinting (parent-of-origin mono-allelic expression) of paternal genes observed in mammals, we constructed haploid and diploid androgenetic zebrafish (Danio rerio). Haploid androgenotes were produced by fertilizing eggs that had been X-ray irradiated to eliminate the maternal genome. Subsequent inhibition of the first mitotic division of haploid androgenotes by heat shock produced diploid androgenotes. The lack of inheritance of maternal-specific DNA markers (RAPD and SSR) by putative diploid and haploid androgenotes confirmed the androgenetic origin of their genomes. Marker analysis was performed on 18 putative androgenotes (five diploids and 13 haploids) from six families. None of 157 maternal-specific RAPD markers analyzed, some of which were apparently homozygous, were passed on to any of these putative androgenotes. A mean of 7.7 maternal-specific markers were assessed per family. The survival of androgenetic zebrafish suggests that if paternal imprinting occurs in zebrafish, it does not result in essential genes being inactivated when their expression is required for development. Production of haploid androgenotes can be used to determine the meiotic recombination rate in male zebrafish. Androgenesis may also provide useful information about the mechanism of sex determination in zebrafish. PMID:8846903

  5. 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

  6. Establishment and dispersal of the biological control weevil Rhinoncomimus latipes on mile-a-minute weed, Persicaria perfoliata

    Treesearch

    Ellen C. Lake; Judith Hough-Goldstein; Kimberley J. Shropshire; Vincent D' Amico

    2011-01-01

    Mile-a-minute weed, Persicaria perfoliata (L.) H. Gross (Polygonaceae), is an annual vine from Asia that has invaded the eastern US where it can form dense monocultures and outcompete other vegetation in a variety of habitats. The host-specific Asian weevil Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) was first...

  7. Mile-a-minute weed (Persicaria perfoliata) and weevil (Rhinoncomimus latipes) response to varying moisture and temperature conditions

    Treesearch

    Scott H. Berg; Judith Hough-Goldstein; Ellen C. Lake; Vincent D' Amico

    2015-01-01

    The combined effects of herbivory and water stress on growth and reproduction of mile-a-minute weed (Persicaria perfoliata (L.) H. Gross) were investigated in greenhouse trials over two years, with well-watered or water-limited plants either exposed or not exposed to herbivory by the mile-a-minute weevil (Rhinoncomimus latipes...

  8. 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.

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

    PubMed

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

    2012-12-01

    Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological control agent of mile-a-minute weed, Persicaria perfoliata (L.) H. Gross, by releasing weevils at the forest edge and monitoring their colonization of potted host plants arrayed along the edge, out into the open field, and into the forest. Both distance from the release cage and habitat where plants were located affected colonization, with more than twice as many weevils found on plants at 2 m than at 6 or 14 m; at 14 m, 6-8 times as many weevils colonized plants along the forest edge compared with plants in the open field or within the forest. In a second experiment, weevils that were released in an open field 12 m from the forest edge initially flew in all directions, but again ultimately colonized more plants at the edge than out in the open field. This species may be adapted to seek host plants at the forest edge, because P. perfoliata generally is found in riparian corridors in its native range and along forest edges in North America. Results suggest that R. latipes will move successfully to new P. perfoliata patches along wooded edges, but may not readily locate isolated patches in the open or those embedded in forests.

  10. Scale development in zebrafish (Danio rerio)

    PubMed Central

    SIRE, JEAN-YVES; ALLIZARD, FRANCOISE; BABIAR, OLIVIER; BOURGUIGNON, JACQUELINE; QUILHAC, ALEXANDRA

    1997-01-01

    In the course of an extensive comparative, structural and developmental study of the cranial and postcranial dermal skeleton (teeth and scales) in osteichthyan fishes, we have undertaken investigations on scale development in zebrafish (Danio (Brachydanio) rerio) using alizarin red staining, and light and transmission electron microscopy. The main goal was to know whether zebrafish scales can be used as a model for further research on the processes controlling the development of the dermal skeleton in general, especially epithelial–mesenchymal interactions. Growth series of laboratory bred specimens were used to study in detail: (1) the relationship of scale appearance with size and age; (2) the squamation pattern; and (3) the events taking place in the epidermis and in the dermis, before and during scale initiation and formation, with the aim of searching for morphological indications of epithelial-mesenchymal interactions. Scales form late in ontogeny, generally when zebrafish are more than 8.0 mm in standard length. Within a population of zebrafish of the same age scale appearance is related to standard length, but when comparing populations of different age the size of the fish at scale appearance is also related to age. Scales always appear first in the posterior region of the body and the squamation then extends anteriorly. Scales develop in the dermis but closely apposed to the epidermal–dermal boundary. Cellular modifications occurring in the basal layer of the epidermis and in the dermis before scale formation clearly indicate that the basal epidermal cells differentiate first, before any evidence of differentiation of the progenitors of the scale-forming cells in the dermis. This strongly suggests that scale differentiation could be initiated by the epidermal basal layer cells which probably produce a molecular signal towards the dermis below. Subsequently dermal cells accumulate close to the epidermis, and differentiate to form scale papillae. The

  11. Are zebrafish Danio rerio males better swimmers than females?

    PubMed

    Leris, I; Sfakianakis, D G; Kentouri, M

    2013-11-01

    Swimming performance of zebrafish Danio rerio males and females initially reared in four different temperatures was assessed by measuring their relative critical swimming speed after acclimation to a common temperature. Males reared at 31° C achieved higher swimming speeds than females reared at the same temperature. Morphometric measurements indicate differences in body shape between sexes that could account for the difference in swimming speed.

  12. 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.

  13. Transcriptional response of marine medaka (Oryzias javanicus) on exposure to toxaphene.

    PubMed

    Woo, Seonock; Yum, Seungshic

    2011-04-01

    Differential gene expression profiles were established from the head and liver tissues of the marine medaka fish (Oryzias javanicus) after its exposure to toxaphene, a persistent organic pollutant and insecticide, using differential display polymerase chain reaction. Twenty-seven differentially expressed genes were identified, which were associated with the cytoskeleton, development, metabolism, nucleic acid/protein binding, and signal transduction. Among these genes, those encoding molecular biomarkers known to be involved in metabolism, ATP hydrolysis, and protein regulation were strongly induced at the transcription level, and genes encoding one structural protein subunit or involved in lipid metabolism were strongly downregulated. The same trends in gene expression changes were observed with real-time PCR analysis of 12 selected clones. The genes identified could be used as molecular biomarkers of biological responses to polychlorinated camphene contamination in aquatic environments.

  14. Comparative embryotoxicity of phenanthrene and alkyl-phenanthrene to marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jingli; Wang, Juying; Jin, Fei; Wang, Xinhong; Hong, Huasheng

    2014-08-30

    Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are the predominant form of PAHs in oil, comprising 85-95% of total PAHs. However, little attention has been paid to these chemicals in ecological risk assessment of marine oil spill. A comparative study of the toxic effects of phenanthrene and retene (7-isopropyl-1-methylphenanthrene, an alkyl-phenanthrene) on the early life stage of marine medaka (Oryzias melastigma) was conducted. Results showed that retene was significantly more toxic than phenanthrene, and marine medaka could be more sensitive to retene than some freshwater fishes. Retene had a higher excretion rate than phenanthrene during the larvae stage. Both of compounds resulted in developmental malformation of marine medaka embryos, with phenanthrene affecting on peripheral vascular system and yolk sac, while retene affecting on cardiac tissues. The toxicity of phenanthrene might be mainly related to its anesthetic effects, and that of retene might be related to the CYP1A-mediated toxicity of its metabolites.

  15. 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...

  16. 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...

  17. 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.

  18. Elemental selenium particles at nano-size (Nano-Se) are more toxic to Medaka (Oryzias latipes) as a consequence of hyper-accumulation of selenium: a comparison with sodium selenite.

    PubMed

    Li, Hongcheng; Zhang, Jinsong; Wang, Thanh; Luo, Wenru; Zhou, Qunfang; Jiang, Guibin

    2008-09-29

    Recent studies have shown that elemental selenium particles at nano-size (Nano-Se) exhibited comparable bioavailability and less toxicity in mice and rats when compared to sodium selenite, selenomethinine and methylselenocysteine. However, little is known about the toxicity profile of Nano-Se in aquatic animals. In the present study, toxicities of Nano-Se and selenite in selenium-sufficient Medaka fish were compared. Selenium bioaccumulation and subsequent clearance in fish livers, gills, muscles and whole bodies were examined after 10 days of exposure to Nano-Se and selenite (100 microg Se/L) and again after 7 days of depuration. Both forms of selenium exposure effectively increased selenium concentrations in the investigated tissues. Surprisingly, Nano-Se was found to be more hyper-accumulated in the liver compared to selenite with differences as high as sixfold. Selenium clearance of both Nano-Se and selenite occurred at similar ratios in whole bodies and muscles but was not rapidly cleared from livers and gills. Nano-Se exhibited strong toxicity for Medaka with an approximately fivefold difference in terms of LC(50) compared to selenite. Nano-Se also caused larger effects on oxidative stress, most likely due to more hyper-accumulation of selenium in liver. The present study suggests that toxicity of nanoparticles can largely vary between different species and concludes that the evaluation of nanotoxicology should be carried out on a case-by-case basis.

  19. CHARACTERISTICS AND TOXICITY OF THE CHLORINATED DRINKING WATER DISINFECTION BY-PRODUCT 3-CHLORO-4-(DICHLOROMETHYL)-5-HYDROXY-2[5H]-FURANONE (MX) TO MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    The compound 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone, also know as MX, is a by-product of wood pulp manufacture and a contaminant of chlorinated drinking and sewage water. MX has recently been shown to be a multi-site carcinogen in rodents. We investigated the acute...

  20. Fitness and field performance of a mass-reared biological control agent, Rhinoncomimus latipes (Coleoptera: Curculionidae).

    PubMed

    Hough-Goldstein, J; Stout, A R; Schoenstein, J A

    2014-08-01

    Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae), a biological control agent of mile-a-minute weed, Persicaria perfoliata (L.) H. Gross, has been mass reared with no infusion of new genetic material for 8-9 yr (at least 24-36 generations), while insects from the same genetic stock have been subject to field conditions in North America for that same period of time. Our main objective was to compare the laboratory population with the field population (and in 1 yr with a Chinese field population) to determine whether genetic changes had occurred, especially ones that may reduce the effectiveness of the laboratory population when released in the field. The laboratory insects laid more eggs and had reduced survival compared with field weevils in several comparisons, and had reduced responsiveness to cues that induce reproductive diapause. Exposure to older plants had the greatest effect on induction of reproductive diapause in both laboratory and field weevils, with effects of daylength and temperature less pronounced. At least a portion of the laboratory weevil population overwintered successfully. Results suggest that it is not necessary to add wild-type genetic material to the rearing colony at this time.

  1. Reconstruction of Danio rerio metabolic model accounting for subcellular compartmentalisation.

    PubMed

    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.

  2. The Effects of Subchronic Exposure to Metribuzin on Danio rerio

    PubMed Central

    Plhalova, Lucie; Stepanova, Stanislava; Praskova, Eva; Chromcova, Lucie; Zelnickova, Lenka; Divisova, Lenka; Skoric, Misa; Pistekova, Vladimira; Bedanova, Iveta; Svobodova, Zdenka

    2012-01-01

    The aim of this study was to assess the impact of metribuzin in surface waters on fish under experimental conditions. The effects of subchronic exposure to metribuzin on fish growth and the development of histopathological changes in selected organs (gill, kidney, liver) and on activity of some biochemical markers (CYP450, EROD) in Danio rerio were investigated during a 28-day toxicity test. Juvenile growth tests were performed on D. rerio according to OECD method number 215. Fish at an initial age of 30 days were exposed to a range of metribuzin concentrations (1.5, 5, 16, 33, and 53 mg L−1). Exposure to metribuzin at 53 mg L−1 was associated with increased mortality. Negative effects with regard to total body weight, length, and the inhibition of specific growth rate were induced at concentrations of 33 and 53 mg L−1. Histopathological examination revealed pathological lesions in the liver in pesticide-exposed fish only at the highest concentration of 53 mg L−1 of metribuzin. Based on the results of growth rate, biochemical markers (CYP450, EROD), and histopathological examination, the lowest observed effect concentration (LOEC) value was 33 mg L−1 and the no observed effect concentration (NOEC) value was 16 mg L−1. PMID:22792050

  3. 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

  4. 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.

  5. Reproductive effects of life-cycle exposure to difenoconazole on female marine medaka (Oryzias melastigma).

    PubMed

    Dong, Xiaocui; Zuo, Zhenghong; Guo, Jiaojiao; Li, Hongbin; Zhang, Lemeng; Chen, Meng; Yang, Zhibin; Wang, Chonggang

    2017-08-01

    Difenoconazole (DFZ) is a widely used triazole fungicide which has been detected in some estuaries and embayments. This study was conducted to investigate the effects of DFZ on ovarian development in female marine medaka (Oryzias melastigma). After 180 days exposure of the embryo to DFZ (0, 1, 10, 100 and 1000 ng/L), the gonadosomatic index and percentage of mature oocytes produced were significantly reduced in the 1, 10 and 100 ng/L treatments but not the 1000 ng/L treatment compared to the control, thus exhibiting a U-shaped dose response curve. The relative mRNA levels of brain follicle-stimulating hormone, ovarian cytochrome P450 aromatase (CYP19s), hepatic estrogen receptors and vitellogenin, and the ratio of 17β-estradiol to testosterone in the muscle, also showed a U-shaped dose response, which was consistent with the development of oocytes. In addition, glutathione S-transferase activity in the ovary showed a U-shaped dose-response. These results gave an explanation for this U-shaped dose-response. The egg number produced, the hatch ability and the swim-up success in the F1 generation all showed a U-shaped dose response, indicating that exposure to DFZ at low concentrations can cause a decrease of fecundity and viability of the next generation. Thus, a more extensive evaluation of the impact of DFZ on marine fish reproduction at realistic environmental concentrations is needed.

  6. 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.

  7. Morphometric Characteristics and Fin Dimorphism between Male and Female on the Marine Medaka, Oryzias dancena

    PubMed Central

    Im, Jae Hyun; Gil, Hyun Woo; Lee, Tae Ho; Kong, Hee Jeong; Ahn, Cheol Min; Kim, Bong Seok; Kim, Dong Soo; Zhang, Chang Ik; Park, In-Seok

    2016-01-01

    ABSTRACT Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka, Oryzias dancena for their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were L∞=30.2 mm, K=3.22/year, and τ0=-0.05. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA, P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka. PMID:28144638

  8. 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.

  9. 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.

  10. 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.

  11. Evaluation of xenoestrogenic potential of propylparaben in zebrafish (Danio rerio).

    PubMed

    Mikula, Premysl; Dobsíková, Radka; Svobodová, Zdenka; Jarkovský, Jirí

    2006-12-01

    Xenoestrogenic potential of propylparaben (PP), one of the most commonly used preservatives in drugs, cosmetics and food, was investigated in vivo using zebrafish (Danio rerio). Juvenile zebrafish (20 days post hatching) were exposed to three different concentrations of propylparaben (PP) dissolved in ethanol and added into the water. After 20 days of exposure the fish were euthanized and vitellogenin concentrations in their whole body homogenates were measured by the method of direct sandwich ELISA. Simultaneously, vitellogenin concentrations in either fish from the control group (exposed to solvent without the substance tested) and in fish from the positive control group (exposed to natural estrogen 17beta-estradiol) were measured. Vitellogenin concentration in whole body homogenates of control fish was 400 (396-540) ng/ml(-1) (geometric mean (95% CI)). Zebrafish exposure to propylparaben at the concentrations of 0.1; 0.4 and 0.9 mg/l(-1) elicited statistically significant decline (P<0.001) of vitellogenin production, i.e. geometric means of vitellogenin concentrations in whole body homogenates were 240 (186-311); 218 (175-270) and 270 (234-311) ng/ml(-1), respectively. Conversely, the geometric mean of vitellogenin concentration in whole body homogenates of zebrafish exposed to 100 ng/ml(-1) of 17beta-estradiol (positive control) was significantly higher (P<0.001) than values in all other groups, i.e. 35,553 (16,860-74,968) ng/ml(-1). Our results suggest an antiestrogenic potential of propylparaben tested in vivo in juvenile zebrafish (Danio rerio). The estrogenic effect of 17beta-estradiol was confirmed.

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

    PubMed

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

    2017-09-06

    Ocean acidification is predicted to affect a wide diversity of marine organisms. However, no studies have reported the effects of ocean acidification on Indian Ocean fish. We have used the Indian Ocean medaka (Oryzias melastigma) as a model species for a marine fish that lives in coastal waters. We investigated the impact of ocean acidification on the embryonic development and the stereotyped escape behavior (mediated by the Mauthner cell) in newly hatched larvae. Newly fertilized eggs of medaka were reared in seawater at three different partial pressures of carbon dioxide (pCO2): control at 450 μatm, moderate at 1160 μatm, and high at 1783 μatm. Hatch rates, embryonic duration, and larval malformation rates were compared and were not significantly different between the treatments and the control. In the high pCO2 group, however, the yolks of larvae were significantly smaller than in the control group, and the newly hatched larvae were significantly longer than the larvae in the control. In the moderate pCO2 group, the eye distance decreased significantly. No significantly negative growth effects were observed in the larvae when exposed to pCO2 levels that are predicted as a result of ocean acidification in the next 100-200 years. Larvae reared under control conditions readily produced C-start escape behavior to mechanosensory stimuli; however, in the moderate and high pCO2 experimental groups, the probabilities of C-start were significantly lower than those of the control group. Therefore, the sensory integration needed for the C-start escape behavior appears to be vulnerable to ocean acidification. Altered behavior in marine larval fish, particularly behaviors involved in escape from predation, could have potentially negative implications to fish populations, and, further, to the marine ecosystems at the levels of CO2 projected for the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Medium composition for effective slow freezing of embryonic cell lines derived from marine medaka (Oryzias dancena).

    PubMed

    Kim, Min Sung; Lee, Seung Tae; Lim, Jeong Mook; Gong, Seung Pyo

    2016-01-01

    This study was conducted to identify optimal medium composition for freezing Oryzias dancena embryonic cell lines. Different freezing media consisting of various concentration of dimethyl sulfoxide (DMSO), fetal bovine serum (FBS), and trehalose were prepared and long-term cultured embryonic cell line was frozen in each freezing medium by conventional slow freezing program for 7 days. Through measurement of viability and growth of post-thaw cells frozen in each freezing medium, it was determined that optimal composition of three components was 10 % DMSO, 20 % FBS, and 0.1 M trehalose. The post-thaw cells frozen in optimal freezing medium showed similar morphology and growth rate with non-frozen cells. Next, this condition was applied to two different sets of experiment; (1) freezing of the same cells during expanded period (57 days) and (2) freezing of short-term cultured cells from other batches for 7 days. The viability of post-thaw cells was significantly low and comparable in set 1 and 2, respectively, when compared with the result of long term-cultured cells frozen in optimal freezing medium for 7 days and similar morphology and growth rate with non-frozen counterparts were detected in the post-thaw cells from both sets. In conclusion, this study first reports the optimal medium composition for freezing O. dancena embryonic cells, which can contribute to fish species preservation as well as improvement of cell-based biotechnology by providing stable cell storage.

  14. Anesthetic effects of clove oil and lidocaine-HCl on marine medaka (Oryzias dancena).

    PubMed

    Park, In-Seok; Park, Sung Jun; Gil, Hyun Woo; Nam, Yoon Kwon; Kim, Dong Soo

    2011-02-01

    Fish may be anesthetized for various experimental and practical purposes, primarily to immobilize them in order to facilitate handling. Marine medaka (Oryzias dancena) is a teleost fish used in marine ecotoxicology studies. Despite the importance of anesthesia in handling experimental fish, the effects of anesthesia in marine medaka have not yet been investigated. In this study, the authors evaluated the anesthetic effects (time required for anesthesia to take effect and recovery time) of two anesthetic agents, clove oil and lidocaine-HCl, on marine medaka. They anesthetized fish at different water temperatures (23 °C, 26 °C and 29 °C) and using different concentrations of clove oil (50 ppm, 75 ppm, 100 ppm, 125 ppm, 150 ppm and 175 ppm) or lidocaine-HCl (300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm and 800 ppm). The time required for anesthesia to take effect decreased significantly as both anesthetic concentration and water temperature increased for both clove oil and lidocaine-HCl. To anesthetize marine medaka within approximately 1 min, the optimal concentrations for clove oil were 125 ppm at 23 °C, 100 ppm at 26 °C and 75 ppm at 29 °C and for lidocaine-HCl were 800 ppm at 23 °C and 700 ppm at both 26 °C and 29 °C. The authors also compared anesthetic effects in marine medaka of different sizes. Both anesthetic exposure time and recovery time were significantly shorter for smaller fish than for larger fish. These results provide a useful foundation for the laboratory handling of marine medaka.

  15. Comparative Study of Growth and Gonad Maturation in Diploid and Triploid Marine Medaka, Oryzias dancena

    PubMed Central

    Park, In-Seok; Gil, Hyun Woo; Lee, Tae Ho; Nam, Yoon Kwon; Kim, Dong Soo

    2016-01-01

    ABSTRACT The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment (0°C) of fertilized eggs for 45 min, applied two minutes after fertilization. The diploid and triploid male fish were larger than their female counterparts (P<0.05), and the concentrations of thyroid stimulating hormone (TSH) and thyroxine (T4) were higher in the induced triploids over 1 year (P<0.05). In both the diploid and tri-ploid groups the concentrations of TSH and T4 were higher in the male fish than in the females (P<0.05), while the testo-sterone and estradiol-17ß concentrations in the induced triploids were lower than in the diploids (P<0.05). The gonadosomatic index (GSI) of the triploid fish was lower than that for the diploids, and the GSI for females in each ploidy group were higher than that for the males. For both groups the GSI was highest at 4 months of age, and decreased thereafter to 12 months. Analysis of the gonads of one-year-old triploid fish suggested that the induction of triploidy probably causes sterility in this species; this effect was more apparent in females than in males. PMID:28144636

  16. Effects of depleted uranium on oxidative stress, detoxification, and defence parameters of zebrafish Danio rerio.

    PubMed

    Gagnaire, Beatrice; Cavalie, Isabelle; Camilleri, Virginie; Adam-Guillermin, Christelle

    2013-01-01

    In this study, we investigated the effects of depleted uranium (DU), the by-product of nuclear enrichment of uranium, on several parameters related to oxidative stress, detoxification, and the defence system in the zebrafish Danio rerio. Several parameters were recorded: phenoloxidase-like (PO) activity, reactive oxygen species (ROS) production, and 7-ethoxyresrufin-O-deethylase (EROD) activity. Experiments were performed on adult and larvae D. rerio. Adult fish were exposed for 28 days at 20 μg U/L followed by a 27-day depuration period. Eggs of D. rerio were exposed for 4 days at 0, 20, 100, 250, 500, and 1,000 μg U/L. Results showed that DU increased ROS production both in adult and in larvae even at the low concentrations tested and even during the depuration period for adult D. rerio. DU also modified PO-like activity, both in the D. rerio adult and larvae experiments, but in a more transient manner. EROD activity was not modified by DU, but sex effects were shown. Results are discussed by way of comparison with other known effects of uranium in fish. Overall, these results show that the mechanisms of action of DU in fish tend to be similar to the ones existing for mammals. These results encourage the development and use of innate immune biomarkers to understand the effects of uranium and, more generally, radionuclides on the fish immune system.

  17. Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio.

    PubMed

    Yim, Eun-Chae; Kim, Hyeon-Joe; Kim, Seong-Jun

    2014-01-01

    An ecofriendly alternative to chemical pesticides is bio-pesticides, which are derived from natural sources. The interest in bio-pesticides is based on the disadvantages associated with chemical pesticides. We conducted acute toxicity assessments of camphor, a major component of bio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphological abnormalities that occurred in Danio rerio (D. rerio) embryos. The median effective concentration of camphor on D. magna after 48 hours was 395.0 μM, and the median lethal concentration on D. rerio embryos after 96 hours was 838.6 μM. The no observed effect concentration and predicted no effect concentration of camphor on D. magna, which was more sensitive than D. rerio, were calculated as 55.2 μM and 3.95 μM, respectively. Morphological abnormalities in D. rerio embryos exposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation of embryos mainly appeared between 24 and 48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissue were observed after 96 hours. The camphor toxicity results suggest that continuous observations on the ecosystem are necessary to monitor toxicity in areas where biological pesticides containing camphor are sprayed.

  18. Growth and Survival of Zebrafish (Danio rerio) Fed Different Commercial and Laboratory Diets

    PubMed Central

    Garris, Heath W.; Jones, Warren T.; Moseley, Dorothy B.; D'Abramo, Louis R.; Watts, Stephen A.

    2009-01-01

    Abstract The need to develop standardized diets to support zebrafish (Danio rerio) research is supported by the knowledge that specific dietary ingredients, nutrients, or antinutritional factors in diets have been shown to affect development and growth of adult D. rerio and their offspring. In this study, there were seven dietary treatments consisting of five commercially available diets and two laboratory-prepared diets, three replicates per treatment. Fish were fed ad libitum twice daily for 9 weeks. At 9 weeks, both weight and length were recorded to determine condition indices. D. rerio fed one of the laboratory-prepared diets had significantly higher weights than individuals fed any of the other diets and exhibited significantly higher lengths than those fed five of the six remaining diets. Although there were significant differences in general growth demographics (length/weight) after the 9-week feeding trial, no significant differences in overall health of D. rerio were observed for the different dietary treatments as determined by statistical analysis of condition factor indices (K=[weight×100]/length3). The success achieved with the laboratory-prepared diets represents the foundation for establishing an open-formulation nutritional standard to ensure that the D. rerio model for research does not generate confounding research results caused by nutritional vagaries. PMID:19566408

  19. Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio

    PubMed Central

    Yim, Eun-Chae; Kim, Hyeon-Joe; Kim, Seong-Jun

    2014-01-01

    Objectives An ecofriendly alternative to chemical pesticides is bio-pesticides, which are derived from natural sources. The interest in bio-pesticides is based on the disadvantages associated with chemical pesticides. Methods We conducted acute toxicity assessments of camphor, a major component of bio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphological abnormalities that occurred in Danio rerio (D. rerio) embryos. Results The median effective concentration of camphor on D. magna after 48 hours was 395.0 μM, and the median lethal concentration on D. rerio embryos after 96 hours was 838.6 μM. The no observed effect concentration and predicted no effect concentration of camphor on D. magna, which was more sensitive than D. rerio, were calculated as 55.2 μM and 3.95 μM, respectively. Morphological abnormalities in D. rerio embryos exposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation of embryos mainly appeared between 24 and 48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissue were observed after 96 hours. Conclusions The camphor toxicity results suggest that continuous observations on the ecosystem are necessary to monitor toxicity in areas where biological pesticides containing camphor are sprayed. PMID:25234414

  20. Global proteomic analysis of lysine acetylation in zebrafish (Danio rerio) embryos.

    PubMed

    Kwon, Oh Kwang; Kim, Sunjoo; Lee, Sangkyu

    2016-12-01

    Lysine acetylation is an important post-translational modification (PTM). Since the development of MS-based proteomics technology, important roles of lysine acetylation beyond histones have focused on chromatin remodeling during the cell cycle and regulation of nuclear transport, metabolism, and translation. Zebrafish (Danio rerio) is a widely used vertebrate model in genetics and biologic studies. Although studies in several mammalian species have been performed, the mechanism of lysine acetylation in D. rerio embryos is incompletely understood. Here, we investigated the global acetylome in D. rerio embryos by using an MS-based proteomics approach. We identified 351 acetylated peptides and 377 nonredundant acetylation sites on 189 lysine-acetylated proteins in 5-day postfertilization (hpf) embryos of D. rerio. Among lysine-acetylated peptides, 40.2% indicated three motifs: (ac)KxxxK, (ac)KxxxxK, and Lx(ac)K. Of 190 acetylated proteins, 81 (42.6%) were mainly distributed in the cytoplasm. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that lysine acetylation in D. rerio was enriched in metabolic pathways. Additionally, 17 of 30 acetylated ribosomal proteins were evolutionarily conserved between zebrafish and humans. Our results indicate that acetyllysine might have regulatory effects on ribosomal proteins involved in protein biosynthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Growth and survival of zebrafish (Danio rerio) fed different commercial and laboratory diets.

    PubMed

    Siccardi, Anthony J; Garris, Heath W; Jones, Warren T; Moseley, Dorothy B; D'Abramo, Louis R; Watts, Stephen A

    2009-09-01

    The need to develop standardized diets to support zebrafish (Danio rerio) research is supported by the knowledge that specific dietary ingredients, nutrients, or antinutritional factors in diets have been shown to affect development and growth of adult D. rerio and their offspring. In this study, there were seven dietary treatments consisting of five commercially available diets and two laboratory-prepared diets, three replicates per treatment. Fish were fed ad libitum twice daily for 9 weeks. At 9 weeks, both weight and length were recorded to determine condition indices. D. rerio fed one of the laboratory-prepared diets had significantly higher weights than individuals fed any of the other diets and exhibited significantly higher lengths than those fed five of the six remaining diets. Although there were significant differences in general growth demographics (length/weight) after the 9-week feeding trial, no significant differences in overall health of D. rerio were observed for the different dietary treatments as determined by statistical analysis of condition factor indices (K = [weight x 100]/length(3)). The success achieved with the laboratory-prepared diets represents the foundation for establishing an open-formulation nutritional standard to ensure that the D. rerio model for research does not generate confounding research results caused by nutritional vagaries.

  2. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-06-01

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

  4. The outflow tract of the heart in fishes: anatomy, genes and evolution.

    PubMed

    Grimes, A C; Kirby, M L

    2009-04-01

    A large number of congenital heart defects associated with mortality in humans are those that affect the cardiac outflow tract, and this provides a strong imperative to understand its development during embryogenesis. While there is wide phylogenetic variation in adult vertebrate heart morphology, recent work has demonstrated evolutionary conservation in the early processes of cardiogenesis, including that of the outflow tract. This, along with the utility and high reproductive potential of fish species such as Danio rerio, Oryzias latipes etc., suggests that fishes may provide ideal comparative biological models to facilitate a better understanding of this poorly understood region of the heart. In this review, the authors present the current understanding of both phylogeny and ontogeny of the cardiac outflow tract in fishes and examine how new molecular studies are informing the phylogenetic relationships and evolutionary trajectories that have been proposed. The authors also attempt to address some of the issues of nomenclature that confuse this area of research.

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

    SciTech Connect

    Dynan, William S.

    2016-11-14

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

  6. 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

  7. 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.

  8. Digestive enzymatic activity during ontogenetic development in zebrafish (Danio rerio).

    PubMed

    Guerrera, Maria Cristina; De Pasquale, Francesca; Muglia, Ugo; Caruso, Gabriella

    2015-12-01

    Despite the growing importance of zebrafish (Danio rerio) as an experimental model in biomedical research, some aspect of physiological and related morphological age dependent changes in digestive system during larval development are still unknown. In this paper, a biochemical and morphological study of the digestive tract of zebrafish was undertaken to record the functional changes occurring in this species during its ontogenetic development, particularly from 24 hr to 47 days post fertilization (dpf). Endo- and exo-proteases, as well as α-amylase enzymes, were quantified in zebrafish larvae before first feeding (7 dpf). The most morphologically significant events during the ontogenesis of the gut occurred between 3 dpf (mouth opening) and 7 dpf (end of exocrine pancreas differentiation). The presence of a wide range of digestive enzymes, already active at earlier zebrafish larval stages, closely related with the omnivorous diet of this species. Increasing enzyme activities were found with increasing age, probably in relation with intestinal mucosa folding and consequent absorption surface increase. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 699-706, 2015. © 2015 Wiley Periodicals, Inc.

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

    PubMed

    Souza, Jaqueline P; Baretta, Jéssica F; Santos, Fabrício; Paino, Ieda M M; Zucolotto, Valtencir

    2017-05-01

    Graphene exhibits unique physical and chemical properties that facilitate its application in many fields, including electronics and biomedical areas. However, the use of graphene and its derivatives could result in accumulation in aquatic environments, and the risks posed by these compounds for organisms are not completely understood. In this study, we investigated the effects of graphene oxide (GO) on adult zebrafish (Danio rerio). Experimental fish were exposed to 2, 10 or 20mgL(-1) GO, and the cytotoxicity, genotoxicity and oxidative stress were assessed. The morphology of the gills and liver tissues was also analyzed. Graphene oxide exposure led to an increase in the number of gill cells that were in early apoptotic and necrotic stages, but genotoxicity was not observed in blood cells. We also observed the generation of Reactive Oxygen Species (ROS) in gill cells. Structural analysis revealed injuries to gill tissues, including a dilated marginal channel, lamellar fusion, clubbed tips, swollen mucocytes, epithelial lifting, aneurysms, and necrosis. Liver tissues also presented lesions such as peripherally located nuclei. Furthermore, hepatocytes exhibited a non-uniform shape, picnotic nuclei, vacuole formation, cell rupture, and necrosis. Our results showed that sub-lethal doses of graphene oxide could be harmful to fish species and thus represent risks for the aquatic food chain. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Pharmacological Analyses of Learning and Memory in Zebrafish (Danio rerio)

    PubMed Central

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

    2015-01-01

    Over the last decade, zebrafish (Danio rerio) have become valuable as a complementary model in behavioral pharmacology, opening a new avenue for understanding the relationships between drug action and behavior. This species offers a useful intermediate approach bridging the gap between in vitro studies and traditional mammalian models. Zebrafish offer great advantages of economy compared to their rodent counterparts, their complex brains and behavioral repertoire offer great translational potential relative to in vitro models. The development and validation of a variety of tests to measure behavior, including cognition, in zebrafish has set the stage for the use of this animal for behavioral pharmacology studies. This has led to research into the basic mechanisms of cognitive function as well as screening for potential cognition-improving drug therapies, among other lines of research. As with all models, zebrafish have limitations, which spans pharmacokinetic challenges to difficulties quantifying behavior. The use, efficacy and limitations associated with a zebrafish model of cognitive function are discussed in this review, within the context of behavioral pharmacology. PMID:25792292

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

    PubMed

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

    2015-12-01

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

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

    PubMed Central

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

    2014-01-01

    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 three 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-day-old zebrafish were exposed to P. hyphessobryconis collected from one 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 not mix zebrafish used in research with other aquarium fishes. PMID:20853741

  13. 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.

  14. Halogenated carbazoles induce cardiotoxicity in developing zebrafish (Danio rerio) embryos.

    PubMed

    Fang, Mingliang; Guo, Jiehong; Chen, Da; Li, An; Hinton, David E; Dong, Wu

    2016-10-01

    Halogenated carbazoles are increasingly identified as a novel class of environmental contaminants. However, no in vivo acute toxicity information on those compounds was available. In the present study, an in vivo zebrafish embryonic model (Danio rerio) was used to investigate the developmental toxicity of those halogenated carbazoles. The results suggested that acute toxicity was structure-dependent. Two of the 6 tested carbazoles, 2,7-dibromocarbazole (27-DBCZ) and 2,3,6,7-tetrachlorocarbazole, showed obvious developmental toxicity at nanomolar levels. The typical phenotypes were similar to dioxin-induced cardiotoxicity, including swollen yolk sac, pericardial sac edema, elongated and unlooped heart, and lower jaw shortening. During embryonic development 27-DBCZ also induced a unique pigmentation decrease. Gene expression and protein staining of cytochrome P4501A (CYP1A) showed that both halogenated carbazoles could induce CYP1A expression at the micromolar level and primarily in the heart area, which was similar to dioxin activity. Further, aryl hydrocarbon receptor-(AhR)2 gene knockdown with morpholino confirmed that the acute cardiotoxicity is AhR-dependent. In conclusion, the results demonstrate that halogenated carbazoles represent yet another class of persistent organic pollutants with dioxin-like activity in an in vivo animal model. Environ Toxicol Chem 2016;35:2523-2529. © 2016 SETAC.

  15. Functional characterization of zebrafish (Danio rerio) Bcl10.

    PubMed

    Mazzone, Pellegrino; Scudiero, Ivan; Ferravante, Angela; Paolucci, Marina; D'Andrea, Luca E; Varricchio, Ettore; Telesio, Gianluca; De Maio, Chiara; Pizzulo, Maddalena; Zotti, Tiziana; Reale, Carla; Vito, Pasquale; Stilo, Romania

    2015-01-01

    The complexes formed by BCL10, MALT1 and specific members of the family of CARMA proteins (CBM complex), have recently focused much attention because they represent a central hub regulating activation of the transcription factor NF-κB following various cellular stimulations. In this manuscript, we report the functional characterization of a Danio rerio 241 amino acids polypeptide ortholog of the Caspase recruiting domain (CARD)-containing protein BCL10. Biochemical studies show that zebrafish Bcl10 (zBcl10) dimerizes and binds to components of the CBM complex. Fluorescence microscopy observations demonstrate that zBcl10 forms cytoplasmic filaments similar to that formed by human BCL10 (hBCL10). Functionally, in human cells zBcl10 is more effective in activating NF-κB compared to hBCL10, possibly due to the lack of carboxy-terminal inhibitory serine residues present in the human protein. Also, depletion experiments carried out through expression of short hairpin RNAs targeting hBCL10 indicate that zBcl10 can functionally replace the human protein. Finally, we show that the zebrafish cell line PAC2 is suitable to carry out reporter assays for monitoring the activation state of NF- kB transcription factor. In conclusion, this work shows that zebrafish may excellently serve as a model organism to study complex and intricate signal transduction pathways, such as those that control NF-κB activation.

  16. Functional Characterization of Zebrafish (Danio rerio) Bcl10

    PubMed Central

    Ferravante, Angela; Paolucci, Marina; D’Andrea, Luca E.; Varricchio, Ettore; Telesio, Gianluca; De Maio, Chiara; Pizzulo, Maddalena; Zotti, Tiziana; Reale, Carla; Vito, Pasquale; Stilo, Romania

    2015-01-01

    The complexes formed by BCL10, MALT1 and specific members of the family of CARMA proteins (CBM complex), have recently focused much attention because they represent a central hub regulating activation of the transcription factor NF-κB following various cellular stimulations. In this manuscript, we report the functional characterization of a Danio rerio 241 amino acids polypeptide ortholog of the Caspase recruiting domain (CARD)-containing protein BCL10. Biochemical studies show that zebrafish Bcl10 (zBcl10) dimerizes and binds to components of the CBM complex. Fluorescence microscopy observations demonstrate that zBcl10 forms cytoplasmic filaments similar to that formed by human BCL10 (hBCL10). Functionally, in human cells zBcl10 is more effective in activating NF-κB compared to hBCL10, possibly due to the lack of carboxy-terminal inhibitory serine residues present in the human protein. Also, depletion experiments carried out through expression of short hairpin RNAs targeting hBCL10 indicate that zBcl10 can functionally replace the human protein. Finally, we show that the zebrafish cell line PAC2 is suitable to carry out reporter assays for monitoring the activation state of NF- kB transcription factor. In conclusion, this work shows that zebrafish may excellently serve as a model organism to study complex and intricate signal transduction pathways, such as those that control NF-κB activation. PMID:25849213

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

    PubMed

    Novoa, B; Bowman, T V; Zon, L; Figueras, A

    2009-02-01

    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 pretreated 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 AMD3100, 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, IL-1 transcript levels were elevated in both unstimulated and LPS stimulated zebrafish Odysseus (CXCR4 deficient mutant) larvae.

  18. Appetite regulation: the central role of melatonin in Danio rerio.

    PubMed

    Piccinetti, Chiara Carla; Migliarini, Beatrice; Olivotto, Ike; Coletti, Giuliana; Amici, Adolfo; Carnevali, Oliana

    2010-11-01

    Melatonin is the hormonal mediator of photoperiodic information to the central nervous system in vertebrates and allows the regulation of energy homeostasis through the establishment of a proper balance between energy intake and energy expenditure. The aim of this study was to evaluate the role of melatonin in appetite central control analyzing the involvement of this hormone in the regulation of feeding behavior in the zebrafish Danio rerio. For this purpose, the effect of two different melatonin doses (100nM and 1μM) administered for 10 days, via water, to zebrafish adults was evaluated at both physiological and molecular level and the effect of melatonin was considered in relation to the most prominent systems involved in appetite regulation. For the first time, in fact, melatonin control of food intake by the modulation of leptin, MC4R, ghrelin, NPY and CB1 gene expression was evaluated. The results obtained indicate that melatonin significantly reduces food intake and the reduction is in agreement with the changes observed at molecular level. A significant increase in genes codifying for molecules involved in feeding inhibition, such as leptin and MC4R, and a significant reduction in the major orexigenic signals including ghrelin, NPY and CB1 are showed here. Taken together these results support the idea that melatonin falls fully into the complex network of signals that regulate food intake thus playing a key role in central appetite regulation.

  19. Chiral bioaccumulation behavior of tebuconazole in the zebrafish (Danio rerio).

    PubMed

    Liu, Na; Dong, Fengshou; Xu, Jun; Liu, Xingang; Zheng, Yongquan

    2016-04-01

    Tebuconazole is an effective chiral fungicide, and previous studies have demonstrated that tebuconazole enantiomers exhibit enantioselective toxicity to non-target aquatic organisms. Thus, the aim of the present study was to investigate the chiral bioaccumulation behavior of tebuconazole in zebrafish (Danio rerio). Two exposure concentrations (0.107 and 1.07 mg/L) of tebuconazole were used. The uptake experiments lasted for 8 days, and subsequently, the zebrafish were transferred to another clean tank containing water without tebuconazole for depuration experiments (up to 14 days). A significant trend in enantioselective bioaccumulation was observed in these zebrafish with the preferential accumulation of (-)-R-tebuconazole at two dose levels. The results of the depuration experiments indicated that the degradation of (-)-R-tebuconazole in zebrafish was slower than that of (+)-S-tebuconazole. The BCFk values for (+)-S-tebuconazole and (-)-R-tebuconazole in a low dose of this chemical were 11.22 and 16.25, respectively, while at a high dose, these values were 9.79 and 10.31, respectively. The enantiomer fraction of tebuconazole in zebrafish and water ranged from 0.31-0.49. Hence, future research should focus on the fate of tebuconazole in the aquatic environment at the enantiomer levels.

  20. Joint toxicity of cadmium and SDBS on Daphnia magna and Danio rerio.

    PubMed

    Zhang, Ying; Ma, Jing; Shi, Liu; Cao, Di; Quan, Xie

    2016-12-01

    Information on joint toxicity is limited. To clarify the joint toxicity and the interactions among toxicants on different aquatic organisms, we investigated the acute toxicity of cadmium and sodium dodecyl benzene sulfonate, two chemicals with high concerns in Chinese waters, on the immobilization of Daphnia magna (D. magna) and the swimming behavior of Danio rerio (D. rerio). Our results illustrated that cadmium and sodium dodecyl benzene sulfonate expressed a synergistic effect on the immobilization of D. magna; and an antagonistic effect on the swimming speed D. rerio, but a synergistic effect on its vertical position in the water column. Based on the observed data, we found the independent action model was more appropriate than the concentration addition model in the prediction of their joint toxicity. Our results gave an example of the joint toxicity investigation, and aided to comprehensive the toxicity action mode of chemical mixtures.

  1. One-dimensional proteomic profiling of Danio rerio embryo vitellogenin to estimate quantum dot toxicity.

    PubMed

    Petushkova, Natalia A; Kuznetsova, Galina P; Larina, Olesya V; Kisrieva, Yulia S; Samenkova, Natalia F; Trifonova, Oxana P; Miroshnichenko, Yuliana V; Zolotarev, Konstantin V; Karuzina, Irina I; Ipatova, Olga M; Lisitsa, Andrey V

    2015-01-01

    Vitellogenin (Vtg) is the major egg yolk protein (YP) in most oviparous species and may be useful as an indicator in ecotoxicological testing at the biochemical level. In this study, we obtained detailed information about the Vtgs of Danio rerio embryos by cutting SDS-PAGE gel lanes into thin slices, and analyzing them slice-by-slice with (MALDI-TOF) mass spectrometry. We conducted three proteomic analyses, comparing embryonic Danio rerio Vtg cleavage products after exposure for 48 h to CdSecore/ZnSshell quantum dots (QDs), after exposure to a mixture of the components used for quantum dot synthesis (MCS-QDs), and in untreated embryos. The Vtg mass spectrometric profiles of the QDs-treated embryos differed from those of the unexposed or MCS-QDs-treated embryos. This study demonstrates the possible utility of Vtg profiling in D. rerio embryos as a sensitive diagnostic tool to estimate nanoparticle toxicity.

  2. The embryotoxicity of ZnO nanoparticles to marine medaka, Oryzias melastigma.

    PubMed

    Cong, Yi; Jin, Fei; Wang, Juying; Mu, Jingli

    2017-04-01

    The negative effects of metal oxide nanoparticles on aquatic environment and organisms have caused much concern. In this study, the embryotoxicity of zinc oxide nanoparticles (ZnO NP) to marine medaka, Oryzias melastigma, was explored and compared with that of aqueous Zn (ZnSO4·7H2O). The Zn(2+) released from ZnO NP in artificial seawater at exposure concentrations was also measured. Results showed that zinc ion release percentage (%) decreased with increasing concentration, which was 44%, 41% and 25% at 0.1, 1 and 10mg/L of ZnO NP suspension, respectively. After 20 d exposure of medaka embryos to ZnO NP, we observed increased mortality and heart rate, reduced percent total hatching success, delayed hatching of embryos and increased malformation% of newly-hatched larvae in ZnO NP treatment compared to the control group. Furthermore, ZnO NPs have significantly greater effects than the aqueous Zn for mortality and heart rate, indicating that ZnO NPs themselves, in particulate or aggregate form, contribute to the observed toxicity. Edema was the most commonly found malformation in newly-hatched larvae after ZnO NP exposure. Overall, our findings suggest that the embryonic stage of marine medaka is sensitive to ZnO NP exposure. Studies of the toxic mechanism of ZnO NPs should not ignore the impact of NPs since the greater effects of ZnO NPs than of aqueous Zn ions observed in this study cannot be explained by the ZnO NP dissolution. The ion release profile of ZnO NPs in marine environment is related to both NP and seawater characteristics, which should be analyzed on a case-by-case basis. The ZnO NP-related Zn speciation may play an important role in the dissolution and toxicity processes of ZnO NPs in marine environment, and further speciation study may contribute to the interpretation of ZnO NP toxicity.

  3. Predictability of food supply, but not ration, increases exploratory behaviour in zebrafish Danio rerio.

    PubMed

    Holley, E D; Ludwig, K J; McEwen, D C; Wisenden, B D

    2014-09-01

    Individual zebrafish Danio rerio were assayed for exploratory tendency in a serial open field test before and after being maintained on one of four diet treatments that differed in ration and in predictability of food delivery. Danio rerio became more exploratory after being maintained on a diet with a predictable delivery schedule. There was no effect of ration. Thus, exploratory behaviour is inducible by environmental influences independent of genetic predisposition or social interactions. These results have implications for management of correlated behavioural syndromes of exploratory and boldness of animals reared in captivity for later release into wild populations. © 2014 The Fisheries Society of the British Isles.

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

    PubMed

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

    2015-09-01

    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.

  5. 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

  6. Development of a promising fish model (Oryzias melastigma) for assessing multiple responses to stresses in the marine environment.

    PubMed

    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.

  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. Neural circuit activity in freely behaving zebrafish (Danio rerio).

    PubMed

    Issa, Fadi A; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L; Papazian, Diane M

    2011-03-15

    Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions.

  9. 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.

  10. 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. Copyright © 2015

  11. 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.

  12. Probiotics can induce follicle maturational competence: the Danio rerio case.

    PubMed

    Gioacchini, Giorgia; Giorgini, Elisabetta; Merrifield, Daniel L; Hardiman, Gary; Borini, Andrea; Vaccari, Lisa; Carnevali, Oliana

    2012-03-01

    In the present study, the effects of the probiotic Lactobacillus rhamnosus IMC 501 on the acquisition of oocyte maturational competence was examined in zebrafish (Danio rerio). L. rhamnosus administration induced the responsiveness of incompetent follicles (stage IIIa) to 17,20-dihydroxy-4-pregnen-3-one and their in vitro maturation. Acquisition of competence by the stage IIIa follicles was further validated by changes of lhr, mprb, inhbaa (activin betaA1), tgfb1, and gdf9 gene expression, which have recently emerged as key regulators of oocyte acquisition of maturational competence, and pou5f1 gene expression, which in other models has been shown to govern the establishment of developmental competence of oocytes. In addition, a DNA microarray experiment was conducted using the same follicles, and with relative gene ontology (GO) data analysis, the molecular effects of probiotic administration emerged. Molecular analysis using PCR-DGGE (denaturing gradient gel electrophoresis) approach, providing information about only the most abundant bacterial members of the microbial community, revealed that the probiotic was able to populate the gastrointestinal tract and modulate the microbial communities, causing a clear shift in them and specifically enhancing the presence of the lactic acid bacteria Streptococcus thermophilus. At the same time, PCR-DGGE analysis revealed that the probiotic was not directly associated with the ovaries. Finally, the effects of probiotic treatment on zebrafish follicle development were also analyzed by FPA (focal plane array) Fourier transform-infrared (FT-IR) imaging, a technique that provides the overall biochemical composition of samples. Changes were found above all in stage IIIa follicles from probiotic-exposed females; the modifications, observed in protein secondary structures as well as in hydration and in bands related to phosphate moieties, allowed us to hypothesize that probiotics act at this follicle stage, affecting the

  13. Neural circuit activity in freely behaving zebrafish (Danio rerio)

    PubMed Central

    Issa, Fadi A.; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L.; Papazian, Diane M.

    2011-01-01

    Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions. PMID:21346131

  14. Peptidomics of the zebrafish Danio rerio: In search for neuropeptides.

    PubMed

    Van Camp, Kristien A; Baggerman, Geert; Blust, Ronny; Husson, Steven J

    2017-01-06

    (Neuro)peptides are small messenger molecules that are derived from larger, inactive precursor proteins by the highly controlled action of processing enzymes. These biologically active peptides can be found in all metazoan species where they orchestrate a wide variety of physiological processes. Obviously, detailed knowledge on the actual peptide sequences, including the potential existence of truncated versions or presence of post-translation modifications, is of high importance when studying their function. A peptidomics approach therefore aims to identify and characterize the endogenously present peptide complement of a defined tissue or organism using liquid chromatography and mass spectrometry. While the zebrafish Danio rerio is considered as an important aquatic model for medical research, neuroscience, development and ecotoxicology, very little is known about their peptidergic signaling cascades. We therefore set out to biochemically characterize endogenously present (neuro)peptides from the zebrafish brain. This peptidomics setup yielded >60 different peptides in addition to various truncated versions. Though the zebrafish is a well-established model organism to study vertebrate biology and gene functions in either a medical or (eco)toxicological context, very little knowledge about neuropeptidergic signaling cascades is available. We therefore set out to characterize endogenously present peptides from the zebrafish brain using a peptidomics setup yielding a total number of 105 peptide identifications. To our knowledge, it is the first attempt to biochemically isolate and characterize neuropeptides from a fish species in a high-throughput manner. This archive of identified endogenous peptides is likely to aid further functional elucidation of defined neuropeptidergic signaling systems (e.g. characterization of cognate G-protein coupled receptors). Furthermore, our methodology allows studying the changes in peptide expression in response to changes in the

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

    PubMed

    Faucher, K; Floriani, M; Gilbin, R; Adam-Guillermin, C

    2012-11-15

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

  16. 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, ...

  17. COMPARATIVE VITELLOGENIC RESPONSES IN THREE TELEOST SPECIES: EXTRAPOLATION TO IN SITU FIELD STUDIES

    EPA Science Inventory

    Induction of vitellogenin (VTG) was compared among three teleostean species to determine their relative sensitivity of exposure to 17b-estradiol (E2). Japanese medaka (Oryzias latipes), sunshine bass (Morone saxatalis x Morone chrysops) and channel catfish (Ictalurus punctatus) ...

  18. 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, ...

  19. COMPARATIVE VITELLOGENIC RESPONSES IN THREE TELEOST SPECIES: EXTRAPOLATION TO IN SITU FIELD STUDIES

    EPA Science Inventory

    Induction of vitellogenin (VTG) was compared among three teleostean species to determine their relative sensitivity of exposure to 17b-estradiol (E2). Japanese medaka (Oryzias latipes), sunshine bass (Morone saxatalis x Morone chrysops) and channel catfish (Ictalurus punctatus) ...

  20. 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…

  1. 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...

  2. 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...

  3. 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...

  4. 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...

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

    PubMed

    Waldron, Ashley L; Cahan, Sara Helms; Franklyn, Christopher S; Ebert, Alicia M

    2017-01-01

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

  6. 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).

  7. 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.

  8. Sensitivity of Danio rerio (Teleostei, Cyprinidae) during two stages of development based on acute toxicity tests.

    PubMed

    Freiry, R; Stelzer, J A A; Maltchik, L; Arenzon, A

    2014-10-01

    The sensitivity of Danio rerio to three chemicals was compared at two growth stages [larval (10 ± 2 after hatching) and post-larval (60 ± 4 days after hatching)] based on acute toxicity tests. Thirty-nine 48 h acute toxicity tests were performed with the substances CuSO4, NaCl and KCl. The 48 h LC50 values at the two growth stages were compared by independent samples t-tests. The results showed a clear decrease in sensitivity when post-larval organisms were used. Since acute toxicity test methods for D. rerio that recommend using post-larval stage fish do not represent the most sensitive stage of the test organism, our study suggests a revision of the methods to use larval fish.

  9. 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

  10. 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.

  11. 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.

  12. Quantitative proteomic analysis reveals the mode-of-action for chronic mercury hepatotoxicity to marine medaka (Oryzias melastigma).

    PubMed

    Wang, Minghua; Wang, Yuyu; Zhang, Ling; Wang, Juan; Hong, Huasheng; Wang, Dazhi

    2013-04-15

    Mercury (Hg) is a widespread persistent pollutant in aquatic ecosystems. We investigated the protein profiles of medaka (Oryzias melastigma) liver chronically exposed to different mercuric chloride (HgCl2) concentrations (1 or 10 μg/L) for 60 d using two-dimensional difference gel electrophoresis (2D-DIGE), as well as cell ultrastructure and Hg content analysis of the hepatic tissue. The results showed that Hg exposure significantly increased metal accumulation in the liver, and subsequently damaged liver ultrastructure. Comparison of the 2D-DIGE protein profiles of the exposed and control groups revealed that the abundance of 45 protein spots was remarkably altered in response to Hg treatment. The altered spots were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, with the resultant identification of 33 spots. These proteins were mainly involved in cytoskeleton assembly, oxidative stress, and energy production. Among them, several proteins related to mitochondrial function (e.g. respiratory metabolism) were significantly altered in the treated hepatocytes, implying that this organelle might be the primary target for Hg attack in the cells. This study provided new insights into the molecular mechanisms and/or toxic pathways by which chronic Hg hepatotoxicity affects aquatic organisms, and also provided basic information for screening potential biomarkers for aquatic Hg monitoring. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    PubMed

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

    2017-04-01

    Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96h-LD50 value was estimated for eleuthero-embryos (1.32ngg(-1)) than that for embryos (1.71ngg(-1)), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems.

  14. Rapid whole brain imaging of neural activity in freely behaving larval zebrafish (Danio rerio).

    PubMed

    Cong, Lin; Wang, Zeguan; Chai, Yuming; Hang, Wei; Shang, Chunfeng; Yang, Wenbin; Bai, Lu; Du, Jiulin; Wang, Kai; Wen, Quan

    2017-09-20

    The internal brain dynamics that link sensation and action are arguably better studied during natural animal behaviors. Here we report on a novel volume imaging and 3D tracking technique that monitors whole brain neural activity in freely swimming larval zebrafish (Danio rerio). We demonstrated the capability of our system through functional imaging of neural activity during visually evoked and prey capture behaviors in larval zebrafish.

  15. Acute toxicity and sublethal effects of fipronil on detoxification enzymes in juvenile zebrafish (Danio rerio).

    PubMed

    Wu, Haihua; Gao, Cuie; Guo, Yaping; Zhang, Yuping; Zhang, Jianzhen; Ma, Enbo

    2014-10-01

    The acute toxicity of fipronil and its sublethal effects on detoxification enzymes (carboxylesterases (CarEs), glutathione S-transferases (GSTs), and 7-ethoxycoumarin O-deethylase (ECOD)) in zebrafish (Danio rerio) were investigated. The results indicated that the 24-h LC50 of fipronil for zebrafish was 220.4 μg/L (95% CI: 173.7-272.4 μg/L). Sublethal concentrations of fipronil did not cause significant changes in CarEs activities. In the liver and muscle tissues, GST activities at the tested concentrations did not significantly differ from those in the control. In the brain and gill tissues, GST activities at a concentration of 4 μg/L were significantly lower than those at a concentration of 2 μg/L. The results suggest that CarEs and GSTs were not suitable biomarkers for fipronil effects in D. rerio. A significant induction in the ECOD activities in the brain, gill, liver, and muscle tissues was observed compared with the control. Moreover, the dose-dependent responses of the ECOD activity were observed after treatment with sublethal concentrations of fipronil in the range of 2-20 μg/L. The results suggested that ECOD could be a suitable biomarker of fipronil effects in D. rerio. Copyright © 2014. Published by Elsevier Inc.

  16. Characterization of the enhancer element of the Danio rerio minor globin gene locus.

    PubMed

    Nefedochkina, Anastasia V; Petrova, Natalia V; Ioudinkova, Elena S; Kovina, Anastasia P; Iarovaia, Olga V; Razin, Sergey V

    2016-04-01

    In Danio rerio, the alpha- and beta-globin genes are present in two clusters: a major cluster located on chromosome 3 and a minor cluster located on chromosome 12. In contrast to the segregated alpha- and beta-globin gene domains of warm-blooded animals, in Danio rerio, each cluster contains both alpha- and beta-globin genes. Expression of globin genes present in the major cluster is controlled by an erythroid-specific enhancer similar to the major regulatory element of mammalian and avian alpha-globin gene domains. The enhancer controlling expression of the globin genes present in the minor locus has not been identified yet. Based on the distribution of epigenetic marks, we have selected two genomic regions that might harbor an enhancer of the minor locus. Using transient transfection of constructs with a reporter gene, we have demonstrated that a ~500-bp DNA fragment located ~1.7 Kb upstream of the αe4 gene possesses an erythroid-specific enhancer active with respect to promoters present in both the major and the minor globin gene loci of Danio rerio. The identified enhancer element harbors clustered binding sites for GATA-1, NF-E2, and EKLF similar to the enhancer of the major globin locus on chromosome 3. Both enhancers appear to have emerged as a result of independent evolution of a duplicated regulatory element present in an ancestral single alpha-/beta-globin locus that existed before teleost-specific genome duplication.

  17. Dexamethasone Modulates Nonvisual Opsins, Glucocorticoid Receptor, and Clock Genes in Danio rerio ZEM-2S Cells.

    PubMed

    Sousa, Jennifer Caroline; Magalhães-Marques, Keila Karoline; da Silveira Cruz-Machado, Sanseray; Moraes, Maria Nathalia; Castrucci, Ana Maria de Lauro

    2017-01-01

    Here we report, for the first time, the differential cellular distribution of two melanopsins (Opn4m1 and Opn4m2) and the effects of GR agonist, dexamethasone, on the expression of these opsins and clock genes, in the photosensitive D. rerio ZEM-2S embryonic cells. Immunopositive labeling for Opn4m1 was detected in the cell membrane whereas Opn4m2 labeling shows nuclear localization, which did not change in response to light. opn4m1, opn4m2, gr, per1b, and cry1b presented an oscillatory profile of expression in LD condition. In both DD and LD condition, dexamethasone (DEX) treatment shifted the peak expression of per1b and cry1b transcripts to ZT16, which corresponds to the highest opn4m1 expression. Interestingly, DEX promoted an increase of per1b expression when applied in LD condition but a decrease when the cells were kept under DD condition. Although DEX effects are divergent with different light conditions, the response resulted in clock synchronization in all cases. Taken together, these data demonstrate that D. rerio ZEM-2S cells possess a photosensitive system due to melanopsin expression which results in an oscillatory profile of clock genes in response to LD cycle. Moreover, we provide evidence that glucocorticoid acts as a circadian regulator of D. rerio peripheral clocks.

  18. 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). Copyright © 2016. Published by Elsevier Inc.

  19. Unusual Fluorescent Granulomas and Myonecrosis in Danio Rerio Infected by the Microsporidian Pathogen Pseudoloma Neurophilia

    PubMed Central

    West, Kylie; Miles, Rodney; Kent, Michael L.

    2014-01-01

    Abstract Zebrafish are a powerful model organism to study disease. Like other animal models, Danio rerio colonies are at risk of pathogenic infection. Microsporidia, a group of intracellular fungus-like parasites, are one potential threat. Microsporidian spores germinate and spread causing pathological changes in the central nervous system, skeletal muscle, and other anatomic sites. Infection can impair breeding, cause other morbidities, and ultimately be lethal. Previously, detecting microsporidia in zebrafish has required sacrificing animals for histopathologic analysis or microscopic examination of fresh tissues. Here, we show that fish with microsporidial infection often have autofluorescent nodules, and we demonstrate infectious spread from nodule-bearing fish to healthy D. rerio. Histologic analyses revealed that fluorescent nodules are granulomatous lesions composed of spores, degenerating muscle, and inflammatory cells. Additional histologic staining verified that microsporidia were present, specifically, Pseudoloma neurophilia. Polymerase chain reaction (PCR)-based testing confirmed the presence of P. neurophilia. Further PCR testing excluded infection by another common zebrafish microsporidial parasite, Pleistophora hyphessobryconis. Collectively, these studies show that P. neurophilia can induce skeletal muscle granulomas in D. rerio, a previously unknown finding. Moreover, since granulomas autofluoresce, microscopic screening for P. neurophilia infection is feasible in live fish, avoiding the need to sacrifice fish for surveillance for this pathogen. PMID:24707848

  20. The effects of CYP1A inhibition on alkyl-phenanthrene metabolism and embryotoxicity in marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jingli; Jin, Fei; Wang, Juying; Wang, Ying; Cong, Yi

    2016-06-01

    Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are the predominant form of PAHs in crude oils, of which, 3-5 ring alkyl-PAH may cause dioxin-like toxicity to early life stages of fish. Retene (7-isopropyl-1-methylphenanthrene), a typical alkyl-phenanthrene compound, can be more toxic than phenanthrene, and the mechanism of retene toxicity is likely related to its rapid biotransformation by cytochrome P450 (CYP) enzymes to metabolites with a wide array of structures and potential toxicities. Here, we investigated how α-naphthoflavone (ANF), a cytochrome P450 1A (CYP1A) inhibitor, affected the embryotoxicity of retene and the role that CYP1A inhibition may play in the interactions. Marine medaka (Oryzias melastigma) embryos were exposed, separately or together, to 200 μg/L retene with 0, 5, 10, 100, and 200 μg/L ANF for 14 days. The results showed that ANF significantly inhibited the induction of CYP1A activity by retene; however, ANF interacted with retene to induce significant developmental toxicity and genotoxicity at 10, 100, and 200 μg/L (p < 0.01). Tissue concentrations of retene and its metabolites and lipid hydroperoxide (LPO) activity also increased, whereas the inhibition of the glutathione S-transferase (GST) activity and the alteration in metabolic profiles of retene were observed. The interactions of retene with ANF indicate that CYP1A inhibition was possibly act through different mechanisms to produce similar developmental effects and genotoxicity. Retene metabolites and altered metabolic profile were likely responsible for retene embryotoxicity to marine medaka. Therefore, elevated toxicity of alkyl-phenanthrene under CYP1A inhibitor suggested that the ecotoxicity of PAHs in coastal water may have underestimated the threat of PAHs to fish or ecosystem.

  1. Effect of short-time exposures to nickel and lead on brain monoamine oxidase from Danio rerio and Poecilia reticulata.

    PubMed

    Senatori, Ornella; Setini, Andrea; Scirocco, Annunziata; Nicotra, Antonietta

    2009-06-01

    The aim of this work was to verify, in two small size freshwater teleosts Danio rerio and Poecilia reticulata, the effects of short-time exposures (24 and 72 h) to a sublethal dose (500 microg/L) of nickel and lead, on brain monoamine oxidase (MAO), an important neural enzyme. The 24-h treatment using both metals caused a strong reduction of MAO activity in D. rerio brain, whereas causing a slight MAO activity stimulation in P. reticulata brain. The same treatment in both species did not affect the brain MAO mRNA production as showed by RT-PCR. Extending the duration of treatment as far as 72 h, partly (D. rerio) or completely (P. reticulata) reversed the metal effects on brain MAO activity suggesting that mechanisms to neutralize the metals had been activated.

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

    PubMed

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

    2017-05-01

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

  3. [Interaction between calcium and lead affects the toxicity to embryo of zebrafish (Danio rerio)].

    PubMed

    Chen, Zhong-Zhi; Zhu, Lin; Yao, Kun; Wang, Xiu-Juan; Ding, Jun-Nan

    2009-04-15

    This study tested the hypothesis that increased Ca2+ content increases the sensitivity of the developing embryos and larvae of zebrafish (Danio rerio) to Pb. And the aim of the study was to investigate the extent to which calcium can individually mitigate lead ion toxicity based on the concept of biotic ligand model (BLM). Embryos of the zebrafish were exposed to various Pb concentrations. Chemical characteristics of water and representative toxicological endpoints of zebrafish embryo were recorded. And general growth retardation as a major toxicological endpoint was used for analysis at 72 h due to its sensitivity and facility. The BLM software of Visual MINTEQ (Version 2.5.2) was employed to calculate the chemical speciation in the solution. The results showed that when Ca2+ concentration increased from 0.25 mmol/L to 2.00 mmol/L, the toxicity of lead on embryos of zebrafish (Danio rerio) decreased markedly after 72 h. And a large part of these decrease can be explained by the positive linear relations between EC50{Pb2+}/EC50[Pb]T (expressed as lead ion activity/dissolved total concentration) and activity/total concentration of Ca2+, through which the influence of Ca2+ on toxicity could be predicted. The results support the assumptions of the BLM and associated with competition between lead and calcium for binding on transport and toxic action sites on biological surfaces. However, when Ca2+ concentration increased from 2.00 mmol/L to 4.00 mmol/L, the toxicity of lead on embryos of zebrafish (Danio rerio) seemed to be constant at 72 h.

  4. Pseudocapillaria tomentosa, a nematode pathogen, and associated neoplasms of zebrafish (Danio rerio) kept in research colonies.

    PubMed

    Kent, Michael L; Bishop-Stewart, Janell K; Matthews, Jennifer L; Spitsbergen, Jan M

    2002-08-01

    Infections with capillarid nematodes were observed in zebrafish (Danio rerio) kept at several research facilities and in a large carcinogen exposure study previously conducted at Oregon State University. We report a morphologic description that identifies the worm as Pseudocapillaria tomentosa, a common nematode of cyprinid and other fishes. Pathologic lesions associated with the infection ranged from inflammatory changes to aggressive neoplasms of the intestine (i.e., intestinal carcinomas and mixed malignant neoplasms). Capillarid nematodes may have intermediate or paratenic hosts. Using a laboratory transmission study, we confirmed that the parasite has a direct life cycle.

  5. Transmission, Diagnosis, and Recommendations for Control of Pseudoloma neurophilia Infections in Laboratory Zebrafish (Danio rerio) Facilities

    PubMed Central

    Murray, Katrina N; Dreska, Mathew; Nasiadka, Andrzej; Rinne, Miranda; Matthews, Jennifer L; Carmichael, Carrie; Bauer, Justin; Varga, Zoltan M; Westerfield, Monte

    2011-01-01

    The microsporidium Pseudoloma neurophilia represents a considerable challenge for laboratory zebrafish (Danio rerio) facilities. In 2010, P. neurophilia infections were diagnosed in zebrafish from 74% of the facilities that submitted fish to the Zebrafish International Resource Center (ZIRC) pathology service, and this organism remains the most commonly diagnosed pathogen in submitted fish. Accordingly, many of the ZIRC pathology service consultations deal with control and prevention of microsporidiosis. Here we describe observations and experiments performed at the ZIRC elucidating aspects of P. neurophilia transmission in zebrafish colonies. We then review current knowledge about P. neurophilia transmission and diagnosis. Considering this information, we present recommendations for control of P. neurophilia in zebrafish facilities. PMID:22330247

  6. Norfloxacin--toxicity for Zebrafish (Danio rerio) focused on oxidative stress parameters.

    PubMed

    Bartoskova, Marta; Dobsikova, Radka; Stancova, Vlasta; Pana, Ondrej; Zivna, Dana; Plhalova, Lucie; Blahova, Jana; Marsalek, Petr

    2014-01-01

    The aim of the study was to investigate the effects of subchronic exposure of zebrafish (Danio rerio) to a fluoroquinolone norfloxacin, using selected oxidative stress parameters as a target. Toxicity tests were performed on zebrafish according to the OECD Guidelines number 203 and number 215. In the Subchronic Toxicity Test, a significant (P < 0.01) increase in the activity of glutathione peroxidase, glutathione S-transferase, and catalase was found. In the test, norfloxacin did not affect lipid peroxidation and catalytic activity of glutathione reductase. From the results, we can conclude that norfloxacin has a negative impact on specific biochemical processes connected with the production of reactive oxygen species in fish tested.

  7. [The behavior of male Danio rerio after exposure of fish embryos to a simulated geomagnetic storm].

    PubMed

    Romanovskiĭ, A V; Pesnia, D S; Izvekov, E I; Krylov, V V; Nepomniashchikh, V A

    2014-01-01

    Embryos of the zebrafish, Danio rerio, were exposed to a simulated geomagnetic storm during 24 hours. Fish, developed from these embryos, left a start chamber to an aquarium more readily in comparison to those reared in a normal geomagnetic field. On the other hand, general locomotor activity in fish was not essentially different between the two groups. We hypothesize that an exposure to a geomagnetic storm during embryonic period results in enhanced tolerance to stress caused by a novel environment. A low level stress is in turn a subject to further exploration.

  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. 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

  10. Behavioural and developmental toxicity of chlorpyrifos and nickel chloride to zebrafish (Danio rerio) embryos and larvae.

    PubMed

    Kienle, Cornelia; Köhler, Heinz-R; Gerhardt, Almut

    2009-09-01

    In order to assess the combined toxicity of environmental chemicals with different modes of action in acute (2 h) and subchronic (11 d) exposures, embryos and larvae of Danio rerio were exposed to a heavy metal salt, nickel chloride (NiCl2), the insecticide chlorpyrifos (CHP) and their binary mixtures. Chlorpyrifos is an acetylcholine esterase inhibitor, which is likely to affect behaviour of the organism. NiCl2 targets the active sites of enzymes and is regarded as an unspecific toxicant for aquatic organisms. Several endpoints, such as locomotor activity, morphological abnormalities, and mortality of D. rerio embryos and larvae were studied. During acute exposures to > or =0.25 mg/L of chlorpyrifos, locomotor activity tended to increase. However, this activity decreased significantly at > or =7.5 mg Ni/L. Subchronic exposures to CHP resulted in behavioural changes at much lower concentrations (> or =0.01 mg/L) and considerably earlier than the observed increase in morphological abnormalities and mortality (LC(50) (10 d): 0.43 mg/L). Combined CHP and NiCl2 mixtures led to an antagonistic deviation from the concept of independent action, in the case of locomotor activity. Compared to developmental or survival parameters, behaviour was the most sensitive endpoint for CHP exposure in this study; therefore we recommend this parameter to complement already established endpoints.

  11. Biomarker responses in zebrafish (Danio rerio) larvae exposed to pristine low-density polyethylene fragments.

    PubMed

    Karami, Ali; Groman, David B; Wilson, Scott P; Ismail, Patimah; Neela, Vasantha K

    2017-04-01

    There are serious concerns over the adverse impacts of microplastics (MPs) on living organisms. The main objective of this study was to test the effects of MPs on the total length, weight, condition factor (CF), transcriptional level of antioxidant, anti and pro-apoptotic, and neurotransmitter genes, and the histopathology of the gill, liver, brain, kidney, and intestine in the larvae of zebrafish (Danio rerio). Fish were exposed to one of three levels of pristine low-density polyethylene (LDPE) fragments (5, 50, or 500 μg/L) for 10 or 20 days. No significant changes were observed in any of the selected biomarkers across MP concentrations at days 10 or 20. The expression of casp9 (caspase 9, apoptosis-related cysteine protease), casp3a (caspase 3, apoptosis-related cysteine protease a) and cat (catalase), however, were significantly lower in the larvae sampled at day 20 than day 10. We provide evidence that virgin short-term exposure to LDPE fragments has minimal impact on biomarker responses in D. rerio larvae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Genome Analysis of Pseudoloma neurophilia: A Microsporidian Parasite of Zebrafish (Danio rerio).

    PubMed

    Ndikumana, Steve; Pelin, Adrian; Williot, Alexandre; Sanders, Justin L; Kent, Michael; Corradi, Nicolas

    2017-01-01

    Microsporidia are highly successful parasites that infect virtually all known animal lineages, including the model Danio rerio (zebrafish). The widespread use of this aquatic model for biomedical research has resulted in an unexpected increase in infections from the microsporidium Pseudoloma neurophilia, which can lead to significant physical, behavioral, and immunological modifications, resulting in nonprotocol variation during experimental procedures. Here, we seek to obtain insights into the biology of P. neurophilia by investigating its genome content, which was obtained from only 29 nanograms of DNA using the MiSeq technology and paired-end Illumina sequencing. We found that the genome of P. neurophilia is phylogenetically and genetically related to other fish-microsporidians, but features unique to this intracellular parasite are also found. The small 5.25-Mb genome assembly includes 1,139 unique open-reading frames and an unusually high number of transposable elements for such a small genome. Investigations of intragenomic diversity also provided strong indications that the mononucleate nucleus of this species is diploid. Overall, our study provides insights into the dynamics of microsporidian genomes and a solid sequence reference to be used in future studies of host-parasite interactions using the zebrafish D. rerio and P. neurophilia as a model. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  13. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Hepatic gene expression profiling in zebrafish (Danio rerio) exposed to the fungicide chlorothalonil.

    PubMed

    Sánchez Garayzar, Anny B; Bahamonde, Paulina A; Martyniuk, Christopher J; Betancourt, Miguel; Munkittrick, Kelly R

    2016-09-01

    Chlorothalonil (tetrachloroisophtalonitrile) is a fungicide that is widely used on agricultural crops around the world and as such, it is a ubiquitous aquatic contaminant. Despite high usage, the effects of this fungicide on non-target aquatic organisms have not been fully investigated. The aim of the present study was to (1) determine the effects of chlorothalonil toxicity on adult male zebrafish (Danio rerio) and (2) characterize the effects of chlorothalonil on gene expression patterns in the liver using two different concentrations of the fungicide, 0.007mg/L (environmentally-relevant) and 0.035mg/L (sublethal). These concentrations were selected from range-finding experiments that showed that zebrafish survival was significantly different from control animals at concentrations higher than 0.035mg/L but not below. Male zebrafish in both treatments of chlorothalonil showed a decrease in liversomatic index. A commercial D. rerio microarray (4×44K) was used to determine gene expression profiles in male zebrafish liver following a 96h toxicological assay. Microarray analysis revealed that males exposed to both 0.007mg/L or 0.035mg/L of chlorothalonil showed increased transcriptional sub-networks related to cell division and DNA damage and decreased expression of gene networks associated with reproduction, immunity, and xenobiotic clearance. This study improves knowledge regarding whole animal exposures to chlorothalonil and identifies molecular signaling cascades that are sensitive to this fungicide in the fish liver. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Acute toxicity and histopathological effects of naproxen in zebrafish (Danio rerio) early life stages.

    PubMed

    Li, Qian; Wang, Peipei; Chen, Ling; Gao, Hongwen; Wu, Lingling

    2016-09-01

    Zebrafish (Danio rerio) embryos and larvae were selected to investigate the potential risk and aquatic toxicity of a widely used pharmaceutical, naproxen. The acute toxicity of naproxen to embryos and larvae was measured, respectively. The histopathology was investigated in the liver of zebrafish larvae after 8-day embryo-larvae exposure to naproxen. The values of 96-h LC50 were 115.2 mg/L for embryos and 147.6 mg/L for larvae, indicating that zebrafish embryos were more sensitive than larvae to naproxen exposure. Large suites of symptoms were induced in zebrafish (D. rerio) early life stages by different dosages of naproxen, including hatching inhibition, lower heart rate, and morphological abnormalities. The most sensitive sub-lethal effect caused by naproxen was pericardial edema, the 72-h EC50 values of which for embryos and larvae were 98.3 and 149.0 mg/L, respectively. In addition, naproxen-treated zebrafish larvae exhibited histopathological liver damage, including swollen hepatocytes, vacuolar degeneration, and nuclei pycnosis. The results indicated that naproxen is a potential threat to aquatic organisms.

  16. 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...

  17. 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...

  18. Toxicity comparison between Chattonella marina and Karenia brevis using marine medaka (Oryzias melastigma): Evidence against the suspected ichthyotoxins of Chattonella marina.

    PubMed

    Shen, Min; Xu, Jingliang; Tsang, Tsui Yun; Au, Doris W T

    2010-07-01

    The marine alga Chattonella marina is often associated with massive fish mortality worldwide. Here, we challenge brevetoxins and free fatty acids as the ichthyotoxins of C. marina by comparing the toxicity of C. marina with a brevetoxins-producing alga Karenia brevis as well as their organic solvent extracts using the seawater medaka Oryzias melastigma. Opposite to K. brevis, toxicity of C. marina was highly correlated with its growth rate and exhibited no dose response relationship between cell density and fish mortality. Fish exposed to C. marina developed significant hyperventilation response, but K. brevis induced hypoventilation response in medaka. Moreover, the organic extracts from C. marina showed no toxicity to fish whereas organic extracts from K. brevis showed significantly higher toxicity than the whole K. brevis culture. The toxins produced by C. marina may be protein in nature or small and labile molecular compounds which are not able to be extracted by traditional organic extraction methods.

  19. 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...

  20. 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...

  1. Metagenomics approach to the study of the gut microbiome structure and function in zebrafish Danio rerio fed with gluten formulated diet.

    PubMed

    Koo, Hyunmin; Hakim, Joseph A; Powell, Mickie L; Kumar, Ranjit; Eipers, Peter G; Morrow, Casey D; Crowley, Michael; Lefkowitz, Elliot J; Watts, Stephen A; Bej, Asim K

    2017-04-01

    In this study, we report the gut microbial composition and predictive functional profiles of zebrafish, Danio rerio, fed with a control formulated diet (CFD), and a gluten formulated diet (GFD) using a metagenomics approach and bioinformatics tools. The microbial communities of the GFD-fed D. rerio displayed heightened abundances of Legionellales, Rhizobiaceae, and Rhodobacter, as compared to the CFD-fed counterparts. Predicted metagenomics of microbial communities (PICRUSt) in GFD-fed D. rerio showed KEGG functional categories corresponding to bile secretion, secondary bile acid biosynthesis, and the metabolism of glycine, serine, and threonine. The CFD-fed D. rerio exhibited KEGG functional categories of bacteria-mediated cobalamin biosynthesis, which was supported by the presence of cobalamin synthesizers such as Bacteroides and Lactobacillus. Though these bacteria were absent in GFD-fed D. rerio, a comparable level of the cobalamin biosynthesis KEGG functional category was observed, which could be contributed by the compensatory enrichment of Cetobacterium. Based on these results, we conclude D. rerio to be a suitable alternative animal model for the use of a targeted metagenomics approach along with bioinformatics tools to further investigate the relationship between the gluten diet and microbiome profile in the gut ecosystem leading to gastrointestinal diseases and other undesired adverse health effects.

  2. Sexually dimorphic morphology and swimming performance relationships in wild-type zebrafish Danio rerio.

    PubMed

    Conradsen, C; McGuigan, K

    2015-11-01

    This study compared prolonged swimming performance (Ucrit ) between male and female Danio rerio, and characterized how body shape was associated with this performance measure in each sex. When swimming in small (n = 6) mixed-sex groups at 28 °C, males swam, on average, over 10 cm s(-1) faster than females despite being significantly smaller. Body shape was sexually dimorphic, with males and females exhibiting small, but statistically significant differences in most aspects of body shape. Body shape explained 18 and 43% of the variation in Ucrit among males and females. In general, effects of body shape on swimming performance appeared to be sex limited, whereby different aspects of body shape affected performance in each sex, although the contribution of the distance between pelvic and anal fins to swimming performance was weakly sexually antagonistic. © 2015 The Fisheries Society of the British Isles.

  3. Differential expression profile of membrane proteins in zebrafish (Danio rerio) brain exposed to methyl parathion.

    PubMed

    Huang, Qing-Yu; Huang, He-Qing

    2011-09-01

    Methyl parathion (MP) is a widely used organophosphorus pesticide, which has been related to a broad spectrum of toxic effects on environmental organisms. The present study investigated the changes in the protein profile of enriched membrane fraction from zebrafish (Danio rerio) brain exposed to three concentrations (0.5, 1 and 2 mg/L) of MP. 2-DE revealed that the abundance of 21 protein spots was significantly changed by MP stress. By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database search, 16 protein spots were identified as membrane proteins, among which 8 were down-regulated, while 8 were up-regulated. These proteins are mainly involved in oxidative stress response, signal transduction, metabolism, protein synthesis and degradation, neuroplasticity and regeneration as well as synaptic transmission. These results may aid our understanding of the mechanism of MP-induced neurotoxicity and provide the possibility of the establishment of candidate biomarkers of MP.

  4. 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

  5. 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.

  6. Norfloxacin—Toxicity for Zebrafish (Danio rerio) Focused on Oxidative Stress Parameters

    PubMed Central

    Bartoskova, Marta; Dobsikova, Radka; Stancova, Vlasta; Pana, Ondrej; Zivna, Dana; Plhalova, Lucie; Blahova, Jana; Marsalek, Petr

    2014-01-01

    The aim of the study was to investigate the effects of subchronic exposure of zebrafish (Danio rerio) to a fluoroquinolone norfloxacin, using selected oxidative stress parameters as a target. Toxicity tests were performed on zebrafish according to the OECD Guidelines number 203 and number 215. In the Subchronic Toxicity Test, a significant (P < 0.01) increase in the activity of glutathione peroxidase, glutathione S-transferase, and catalase was found. In the test, norfloxacin did not affect lipid peroxidation and catalytic activity of glutathione reductase. From the results, we can conclude that norfloxacin has a negative impact on specific biochemical processes connected with the production of reactive oxygen species in fish tested. PMID:24783212

  7. 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.

  8. Acute effects of mercuric chloride on glycogen and protein content of zebra fish, Danio rerio.

    PubMed

    Vutukuru, S S; Basani, Kalpana

    2013-03-01

    Presence of mercury and other heavy metals above permissible levels in water bodies across the globe is posing a serious threat to aquatic biota and public health. Occurrence of mercury above the permissible limits in the aquatic ecosystem of Hyderabad city is well established. In this context, we carried out static- renewal bioassays on the zebra fish, Danio rerio exposed to different concentrations of mercuric chloride, and the 96-h median lethal concentration (LC50) was found to be 0.077 mgl(-1). Behavioral manifestations like loss of scales, hyper secretion of mucus, surfacing and darting movements, loss of balance, irregular swimming patterns were noticed in the fish exposed to 0.077 mgl(-1). The present study also examined the toxic effects of mercuric chloride on vital biochemical constituent's total glycogen and total protein. Significant decrease (p < 0.001) in glycogen and protein content of fish exposed to 0.077 mgl(-1).

  9. Reproductive toxicity of chlorpyrifos tested in zebrafish (Danio rerio): Histological and hormonal end points.

    PubMed

    Manjunatha, Bangeppagari; Philip, Gundala Harold

    2016-10-01

    This study was carried out to find out whether exposure to environmentally relevant concentration of chlorpyrifos (CP) modulates reproductive competence. To understand this, eight adult male and eight adult female zebrafish (Danio rerio) were exposed to 200 µg/L of CP for 24, 48, 72, and 96 h. Vitellogenin levels did not show much change in female fish, whereas in male the levels increased with increasing exposure time thereby indicating estrogenecity of the toxicant. Attenuation of serum 11-ketotestosterone in male and serum 17β-estradiol in female was noticed in the exposed fish and thus signified interference of CP in the reproductive endocrine system. Structural damage common to both the gonads was vacuolization. Elongation of seminiferous tubules in testes and atretic follicles in ovary was also observed. © The Author(s) 2015.

  10. 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

  11. Toxic effects of magnesium oxide nanoparticles on early developmental and larval stages of zebrafish (Danio rerio).

    PubMed

    Ghobadian, Mehdi; Nabiuni, Mohammad; Parivar, Kazem; Fathi, Mojtaba; Pazooki, Jamileh

    2015-12-01

    Magnesium oxide nanoparticles (MgONPs) are used in medicine, manufacturing and food industries. Because of their extensive application in our daily lives, environmental exposure to these nanoparticles is inevitable. The present study examined the effects of MgONPs on zebrafish (Danio rerio) early developmental stages. The results showed that, at different concentrations, MgONPs induced cellular apoptosis and intracellular reactive oxygen species. The hatching rate and survival of embryos decreased in a dose dependent manner. The 96-h LC50 value of MgONPs on zebrafish survival was 428 mg/l and the 48-h EC50 value of MgONPs on zebrafish embryo hatching rate was 175 mg/l. Moreover different types of malformation were observed in exposed embryos. The results demonstrate the toxic effects of MgONPs on zebrafish embryos and emphasize the need for further studies.

  12. Identification of Fusarium solani species complex from infected zebrafish (Danio rerio).

    PubMed

    Ke, Xiaoli; Lu, Maixin; Wang, Jianguo

    2016-11-01

    Although Fusarium sp. infections have been reported in aquatic invertebrates, studies of Fusarium spp. as fish pathogens remain very limited. In our study, a fungus was isolated from diseased zebrafish (Danio rerio). DNA sequence analysis of the fungus, based on a partial region of the translation elongation factor 1α gene (EF-1α), the internal transcribed spacer region and domains D1 and D2 of the large subunit of the ribosomal RNA gene (ITS plus LSU), and the RNA polymerase II subunit gene (RPB2), showed 99.9-100% homology to Fusarium solani species complex sequences. Multilocus sequence typing analysis based on 3-locus haplotypes (EF-1α, ITS plus LSU, and RPB2) suggests that the isolated strain was type 3+4-P. Challenge experiments showed that this organism could be pathogenic to zebrafish, but usually does not infect healthy subjects under normal circumstances.

  13. Two classes of deleterious recessive alleles in a natural population of zebrafish, Danio rerio.

    PubMed Central

    McCune, Amy R.; Houle, David; McMillan, Kyle; Annable, Rebecca; Kondrashov, Alexey S.

    2004-01-01

    Natural populations carry deleterious recessive alleles which cause inbreeding depression. We compared mortality and growth of inbred and outbred zebrafish, Danio rerio, between 6 and 48 days of age. Grandparents of the studied fish were caught in the wild. Inbred fish were generated by brother-sister mating. Mortality was 9% in outbred fish, and 42% in inbred fish, which implies at least 3.6 lethal equivalents of deleterious recessive alleles per zygote. There was no significant inbreeding depression in the growth, perhaps because the surviving inbred fish lived under less crowded conditions. In contrast to alleles that cause embryonic and early larval mortality in the same population, alleles responsible for late larval and early juvenile mortality did not result in any gross morphological abnormalities. Thus, deleterious recessive alleles that segregate in a wild zebrafish population belong to two sharply distinct classes: early-acting, morphologically overt, unconditional lethals; and later-acting, morphologically cryptic, and presumably milder alleles. PMID:15451692

  14. DNA methylation of genes of the main components of the telomerase complex in Danio rerio.

    PubMed

    Belova, E V; Kozlov, A E; Shubernetskaya, O S; Zvereva, M I; Shpanchenko, O V; Dontsova, O A

    2015-01-01

    The methylation status of the genes of telomerase reverse transcriptase (tert) and telomerase RNA (terc) was determined in brain tissues of Danio rerio of different age. It is found that, regardless of the age of fish, the regulatory region of the tert gene was completely methylated, whereas the coding region remained unmethylated in all cases. The level of methylation of the region located downstream of the coding region of the terc gene changes with age. This region was analyzed in the samples of other tissues, and its methylation status was also nonuniform. The alteration of the methylation status in the 3'-untranslated region of the terc gene suggests the possibility of transcription of the antisense strand in this region.

  15. 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.

  16. Individual and mixture effects of five agricultural pesticides on zebrafish (Danio rerio) larvae.

    PubMed

    Wang, Yanhua; Yang, Guiling; Dai, Dejiang; Xu, Zhenlan; Cai, Leiming; Wang, Qiang; Yu, Yijun

    2017-02-01

    In the present study, we evaluated the individual and mixture toxicities of imidacloprid and other four pesticides (atrazine, chlorpyrifos, butachlor, and λ-cyhalothrin) to the zebrafish (Danio rerio) larvae in order to clarify the interactive effects of pesticides on aquatic organisms. Results from the 96-h semi-static toxicity test indicated that chlorpyrifos, λ-cyhalothrin, and butachlor had the highest toxicities to D. rerio with an LC50 value ranging from 0.28 (0.13∼0.38) to 0.45 (0.31∼0.59) mg AI L(-1), followed by atrazine with an LC50 value of 15.63 (10.71∼25.76) mg AI L(-1), while imidacloprid exhibited the least toxicity to the organisms with an LC50 value of 143.7 (99.98∼221.6) mg AI L(-1). Seven pesticide mixtures (two binary mixtures of imidacloprid + atrazine and imidacloprid + λ-cyhalothrin, two ternary mixtures of imidacloprid + atrazine + λ-cyhalothrin and imidacloprid + butachlor + λ-cyhalothrin, two quaternary mixtures of imidacloprid + atrazine + chlorpyrifos + λ-cyhalothrin and imidacloprid + chlorpyrifos + butachlor + λ-cyhalothrin, and one quinquenary mixture of imidacloprid + atrazine + chlorpyrifos + butachlor + λ-cyhalothrin) exhibited synergistic effects with equitoxic ratio and equivalent concentration on the zebrafish. Our results highlighted that the simultaneous presence of several pesticides in the aquatic environment might lead to increased toxicity, causing serious damage to the aquatic ecosystems compared with their individual toxicities. Therefore, the toxic effects of both individual pesticides and their mixtures should be incorporated into the environmental risk evaluation of pesticides.

  17. Glyphosate Adversely Affects Danio rerio Males: Acetylcholinesterase Modulation and Oxidative Stress.

    PubMed

    Lopes, Fernanda Moreira; Caldas, Sergiane Souza; Primel, Ednei Gilberto; da Rosa, Carlos Eduardo

    2017-04-01

    It has been demonstrated that glyphosate-based herbicides are toxic to animals. In the present study, reactive oxygen species (ROS) generation, antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO), as well as the activity and expression of the acetylcholinesterase (AChE) enzyme, were evaluated in Danio rerio males exposed to 5 or 10 mg/L of glyphosate for 24 and 96 h. An increase in ACAP in gills after 24 h was observed in the animals exposed to 5 mg/L of glyphosate. A decrease in LPO was observed in brain tissue of animals exposed to 10 mg/L after 24 h, while an increase was observed in muscle after 96 h. No significant alterations were observed in ROS generation. AChE activity was not altered in muscles or brains of animals exposed to either glyphosate concentration for 24 or 96 h. However, gene expression of this enzyme in the brain was reduced after 24 h and was enhanced in both brain and muscle tissues after 96 h. Thus, contrary to previous findings that had attributed the imbalance in the oxidative state of animals exposed to glyphosate-based herbicides to surfactants and other inert compounds, the present study demonstrated that glyphosate per se promotes this same effect in zebrafish males. Although glyphosate concentrations did not alter AChE activity, this study demonstrated for the first time that this molecule affects ache expression in male zebrafish D. rerio.

  18. The effects of protein and fiber content on gut structure and function in zebrafish (Danio rerio).

    PubMed

    Leigh, Samantha C; Nguyen-Phuc, Bao-Quang; German, Donovan P

    2017-09-15

    Chemical reactor theory (CRT) suggests that the digestive tract functions as a chemical reactor for processing food. Presumably, gut structure and function should match diet to ensure adequate nutrient and energy uptake to maintain performance. Within CRT, dietary biochemical composition is the most important factor affecting gut structure and function in vertebrates. We fed Danio rerio (zebrafish) diets ranging from high- to moderate- to low-quality (i.e., ranging from high-protein, low-fiber to low-protein, high-fiber), and observed how gut length and surface area, as well as the activity levels of digestive enzymes (amylase, maltase, trypsin, aminopeptidase, and lipase) shifted in response to these dietary changes. Fish on the low-quality diet had the longest guts with the largest intestinal epithelial surface area and enterocyte cellular volumes. Fish on the moderate-quality diet had intermediate values of most of these parameters, and fish on the high-quality diet, the lowest. These data largely support CRT. Digestive enzyme activity levels were generally elevated in fish fed the moderate- and low-quality diets, but were highest in the fish fed the moderate-quality diet, suggesting that a diet with protein levels closest to that of the natural diet of D. rerio (they are omnivorous in nature) may elicit the best gut performance. However, fish fed the carnivore diet reached the largest terminal body size. Our results support CRT in terms of gut structure; however, our enzyme results do not necessarily agree with CRT and largely depend on which enzyme is discussed. In particular, the evidence for lipase activities being elevated in the fish fed the low-protein, high-fiber diet perhaps reflects a lipid-scavenging mechanism in fish consuming high-fiber foods rather than CRT.

  19. 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. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  20. Comparison of diazinon toxicity to embryos of Xenopus laevis and Danio rerio; degradation of diazinon in water.

    PubMed

    Modra, Helena; Vrskova, Dagmar; Macova, Stanislava; Kohoutkova, Jana; Hajslova, Jana; Haluzova, Ivana; Svobodova, Zdenka

    2011-06-01

    The aim of this study was to determine the toxic effect of diazinon (organophosphate insecticide) to embryos of Xenopus laevis and Danio rerio. The 96-h LC₅₀ values showed higher toxicity of diazinon for X. leavis in standard solution (9.84 mg/L) compared to the pond water (12.64 mg/L). Teratogenic index for diazinon was 1.3 and 1.6, respectively. The 96-h LC₅₀ diazinon values demonstrated similar sensitivity of embryos D. rerio (8.21-9.34 mg/L) and X. laevis in standard test solutions. Our results reflect that direct application of diazinon into the water can be associated with significant risks to aquatic organisms.

  1. Single and joint toxic effects of five selected pesticides on the early life stages of zebrafish (Denio rerio).

    PubMed

    Wang, Yanhua; Lv, Lu; Yu, Yijun; Yang, Guiling; Xu, Zhenlan; Wang, Qiang; Cai, Leiming

    2017-03-01

    Instead of individual ones, pesticides are usually detected in water environment as mixtures of contaminants. Laboratory tests were conducted in order to investigate the effects of individual and joint pesticides (phoxim, atrazine, chlorpyrifos, butachlor and λ-cyhalothrin) on zebrafish (Denio rerio). Results from 96-h semi-static toxicity test indicated that λ-cyhalothrin had the greatest toxicity to the three life stages (embryonic, larval and juvenile stages) of D. rerio with LC50 values ranging from 0.0031 (0.0017-0.0042) to 0.38 (0.21-0.53) mg a.i. L(-1), followed by butachlor and chlorpyrifos with LC50 values ranging from 0.45 (0.31-0.59) to 1.93 (1.37-3.55) and from 0.28 (0.13-0.38) to 13.03 (7.54-19.71) mg a.i. L(-1), respectively. In contrast, atrazine showed the least toxicity with LC50 values ranging from 6.09 (3.34-8.35) to 34.19 (24.42-51.9) mg a.i. L(-1). The larval stage of D. rerio was a vulnerable period to most of the selected pesticides in the multiple life stages tested. Pesticide mixtures containing phoxim and λ-cyhalothrin exerted synergistic effects on the larvae of D. rerio. Moreover, the binary mixture of phoxim-atrazine also displayed synergistic response to zebrafish. It has been assumed that most chemicals are additive in toxicity. Therefore, it is crucial to clarify the synergistic interaction for pesticide regulators and environment managers. In the present study, our data provided a clear picture on ecological risk of these pesticide mixtures to aquatic organisms. Moreover, joint effects play a more important role than individual ones, which require more attention when defining standard for water environment quality and risk assessment protocols. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 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.

  3. The Caudal Skeleton of the Zebrafish, Danio rerio, from a Phylogenetic Perspective: A Polyural Interpretation of Homologous Structures

    PubMed Central

    Wiley, Edward O.; Fuiten, Allison M.; Doosey, Michael H.; Lohman, Brian K.; Merkes, Christopher; Azuma, Mizuki

    2016-01-01

    The structure of the caudal skeleton of extant teleost fishes has been interpreted in two different ways. In a diural interpretation, a caudal skeleton is composed of two centra articulated with one to six hypurals. Most subsequent authors have followed this interpretation. In contrast, a polyural interpretation considers the teleost fin to be derived from a fully metameristic ancestral bauplan originally composed of a one-to-one relationship between neural arches, centra (when present), and hypurals. Three different interpretations of the identity and homology of skeletal components of the caudal skeleton of the teleost fish Danio rerio have been proposed, two from a diural perspective and one from a polyural perspective. We examine each caudal skeletal component of Danio rerio from both a developmental and phylogenetic perspective. We propose that a polyural interpretation of structures is consistent with the current interpretation of the basal neopterygian caudal fin for this model organism rather than the older diural interpretation that does not take into account the metamerism observed in caudal structures during development. The polyural interpretation suggests several shared evolutionary innovations of major clades that would remain undiscovered under the older diural naming paradigm and makes the terminology of the parts of the caudal fin of Danio rerio strictly comparable to more basal fishes. PMID:28250540

  4. 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.

  5. The Caudal Skeleton of the Zebrafish, Danio rerio, from a Phylogenetic Perspective: A Polyural Interpretation of Homologous Structures.

    PubMed

    Wiley, Edward O; Fuiten, Allison M; Doosey, Michael H; Lohman, Brian K; Merkes, Christopher; Azuma, Mizuki

    2015-01-01

    The structure of the caudal skeleton of extant teleost fishes has been interpreted in two different ways. In a diural interpretation, a caudal skeleton is composed of two centra articulated with one to six hypurals. Most subsequent authors have followed this interpretation. In contrast, a polyural interpretation considers the teleost fin to be derived from a fully metameristic ancestral bauplan originally composed of a one-to-one relationship between neural arches, centra (when present), and hypurals. Three different interpretations of the identity and homology of skeletal components of the caudal skeleton of the teleost fish Danio rerio have been proposed, two from a diural perspective and one from a polyural perspective. We examine each caudal skeletal component of Danio rerio from both a developmental and phylogenetic perspective. We propose that a polyural interpretation of structures is consistent with the current interpretation of the basal neopterygian caudal fin for this model organism rather than the older diural interpretation that does not take into account the metamerism observed in caudal structures during development. The polyural interpretation suggests several shared evolutionary innovations of major clades that would remain undiscovered under the older diural naming paradigm and makes the terminology of the parts of the caudal fin of Danio rerio strictly comparable to more basal fishes.

  6. Effects of Subchronic Exposure of Diclofenac on Growth, Histopathological Changes, and Oxidative Stress in Zebrafish (Danio rerio)

    PubMed Central

    Praskova, Eva; Plhalova, Lucie; Chromcova, Lucie; Stepanova, Stanislava; Bedanova, Iveta; Blahova, Jana; Hostovsky, Martin; Skoric, Misa; Maršálek, Petr; 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. PMID:24688414

  7. Danio rerio αE-catenin Is a Monomeric F-actin Binding Protein with Distinct Properties from Mus musculus αE-catenin*

    PubMed Central

    Miller, Phillip W.; Pokutta, Sabine; Ghosh, Agnidipta; Almo, Steven C.; Weis, William I.; Nelson, W. James; Kwiatkowski, Adam V.

    2013-01-01

    It is unknown whether homologs of the cadherin·catenin complex have conserved structures and functions across the Metazoa. Mammalian αE-catenin is an allosterically regulated actin-binding protein that binds the cadherin·β-catenin complex as a monomer and whose dimerization potentiates F-actin association. We tested whether these functional properties are conserved in another vertebrate, the zebrafish Danio rerio. Here we show, despite 90% sequence identity, that Danio rerio and Mus musculus αE-catenin have striking functional differences. We demonstrate that D. rerio αE-catenin is monomeric by size exclusion chromatography, native PAGE, and small angle x-ray scattering. D. rerio αE-catenin binds F-actin in cosedimentation assays as a monomer and as an α/β-catenin heterodimer complex. D. rerio αE-catenin also bundles F-actin, as shown by negative stained transmission electron microscopy, and does not inhibit Arp2/3 complex-mediated actin nucleation in bulk polymerization assays. Thus, core properties of α-catenin function, F-actin and β-catenin binding, are conserved between mouse and zebrafish. We speculate that unique regulatory properties have evolved to match specific developmental requirements. PMID:23788645

  8. Danio rerio αE-catenin is a monomeric F-actin binding protein with distinct properties from Mus musculus αE-catenin.

    PubMed

    Miller, Phillip W; Pokutta, Sabine; Ghosh, Agnidipta; Almo, Steven C; Weis, William I; Nelson, W James; Kwiatkowski, Adam V

    2013-08-02

    It is unknown whether homologs of the cadherin·catenin complex have conserved structures and functions across the Metazoa. Mammalian αE-catenin is an allosterically regulated actin-binding protein that binds the cadherin·β-catenin complex as a monomer and whose dimerization potentiates F-actin association. We tested whether these functional properties are conserved in another vertebrate, the zebrafish Danio rerio. Here we show, despite 90% sequence identity, that Danio rerio and Mus musculus αE-catenin have striking functional differences. We demonstrate that D. rerio αE-catenin is monomeric by size exclusion chromatography, native PAGE, and small angle x-ray scattering. D. rerio αE-catenin binds F-actin in cosedimentation assays as a monomer and as an α/β-catenin heterodimer complex. D. rerio αE-catenin also bundles F-actin, as shown by negative stained transmission electron microscopy, and does not inhibit Arp2/3 complex-mediated actin nucleation in bulk polymerization assays. Thus, core properties of α-catenin function, F-actin and β-catenin binding, are conserved between mouse and zebrafish. We speculate that unique regulatory properties have evolved to match specific developmental requirements.

  9. Body length rather than routine metabolic rate and body condition correlates with activity and risk-taking in juvenile zebrafish Danio rerio.

    PubMed

    Polverino, G; Bierbach, D; Killen, S S; Uusi-Heikkilä, S; Arlinghaus, R

    2016-11-01

    In this study, the following hypotheses were explored using zebrafish Danio rerio: (1) individuals from the same cohort differ consistently in activity and risk-taking and (2) variation in activity and risk-taking is linked to individual differences in metabolic rate, body length and body condition. To examine these hypotheses, juvenile D. rerio were tested for routine metabolic rate and subsequently exposed to an open field test. Strong evidence was found for consistent among-individual differences in activity and risk-taking, which were overall negatively correlated with body length, i.e. larger D. rerio were found to be less active in a potentially dangerous open field and a similar trend was found with respect to a more direct measure of their risk-taking tendency. In contrast, routine metabolic rate and body condition were uncorrelated with both activity and risk-taking of juvenile D. rerio. These findings suggest that body length is associated with risk-related behaviours in juvenile D. rerio for which larger, rather than smaller, individuals may have a higher risk of predation, while the role for routine metabolic rate is relatively limited or non-existent, at least under the conditions of the present study. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

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

    PubMed

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

    2017-07-13

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

  11. 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.

  12. Assessing the toxicity of triphenyltin to different life stages of the marine medaka Oryzias melastigma through a series of life-cycle based experiments.

    PubMed

    Yi, Xianliang; Leung, Kenneth M Y

    2017-02-24

    Toxic effects of triphenyltin (TPT) to different life stages of the marine medaka Oryzias melastigma were investigated through a series of life-cycle based exposure experiments. In embryo stage, TPT exposure could elevate the heartbeat rate at Day 6-8 post-fertilization and increase the expression levels of five heart development related genes (i.e., ATPase, COX2, BMP4, GATA4 and NKX2.5). In larval stage, TPT shortened the body length at ≥10μg/L and suppressed the swimming activity of the fish larvae at Day 1 post-hatching at 50μg/L. In reproductive stage, TPT exposure resulted in a male-biased sex ratio (2μg/L) and reduced the gonadosomatic index (GSI) in females (≥ 0.1μg/L), which might in turn lead to a decline in their population fitness. The reproductive stage of O. melastigma was more sensitive to TPT than other stages, while the GSI of female medaka was the most sensitive endpoint.

  13. The role of cytochrome P4501A activity inhibition in three- to five-ringed polycyclic aromatic hydrocarbons embryotoxicity of marine medaka (Oryzias melastigma).

    PubMed

    Mu, Jing-li; Wang, Xin-hong; Jin, Fei; Wang, Ju-ying; Hong, Hua-sheng

    2012-07-01

    The mode of action of PAHs that causes fish developmental malformations is unclear. The embryotoxicity of marine medaka (Oryzias melastigma) was investigated after individual exposure to three- to five-ring PAHs Phe, Py, and BaP or co-exposure with α-ANF for 18 days. We found that the relationships between EROD induction and developmental deformities of embryos showed a various pattern under different exposure scenarios of Phe, Py, and BaP, which suggested possibly different modes of action in determining the developmental toxicities. As for co-exposure scenarios of each PAH combined with ANF, it showed potentially synergistic effects. The inhibited CYP1A mediated enzyme activity by ANF after co-exposure did not effectively alleviate developmental toxicity of embryo. It showed potentially synergistic effects after co-exposure of marine fish embryos to CYP1A inhibitors and PAH-type CYP1A inducers. Heart deformities in the early life stages of marine medaka were recommended as a biomarker for indicating the extent of PAH pollution.

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

    PubMed

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

    2011-03-30

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

  15. Carotenoid glycosides from cyanobacteria are teratogenic in the zebrafish (Danio rerio) embryo model.

    PubMed

    Jaja-Chimedza, Asha; Sanchez, Kristel; Gantar, Miroslav; Gibbs, Patrick; Schmale, Michael; Berry, John P

    2017-05-01

    Toxigenicity of cyanobacteria is widely associated with production of several well-described toxins that pose recognized threats to human and ecosystem health as part of both freshwater eutrophication, and episodic blooms in freshwater and coastal habitats. However, a preponderance of evidence indicates contribution of additional bioactive, and potentially toxic, metabolites. In the present study, the zebrafish (Danio rerio) embryo was used as a model of vertebrate development to identify, and subsequently isolate and characterize, teratogenic metabolites from two representative strains of C. raciborskii. Using this approach, three chemically related carotenoids - and specifically the xanthophyll glycosides, myxol 2'-glycoside (1), 4-ketomyxol 2'-glycoside (2) and 4-hydroxymyxol 2'-glycoside (3) - which are, otherwise, well known pigment molecules from cyanobacteria were isolated as potently teratogenic compounds. Carotenoids are recognized "pro-retinoids" with retinoic acid, as a metabolic product of the oxidative cleavage of carotenoids, established as both key mediator of embryo development and, consequently, a potent teratogen. Accordingly, a comparative toxicological study of chemically diverse carotenoids, as well as apocarotenoids and retinoids, was undertaken. Based on this, a working model of the developmental toxicity of carotenoids as pro-retinoids is proposed, and the teratogenicity of these widespread metabolites is discussed in relation to possible impacts on aquatic vertebrate populations.

  16. 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.

  17. Do laboratory rearing conditions affect auditory and mechanosensory development of zebrafish (Danio rerio)?

    NASA Astrophysics Data System (ADS)

    Poling, Kirsten R.; Jaworski, Eva; Fantetti, Kristen R.; Higgs, Dennis M.

    2005-04-01

    The effect of anthropogenic noise on the fish auditory system has become of increasing concern due to possible detrimental effects of intense sounds on auditory function and structures. This is especially problematic when raising fish in laboratory and aquaculture settings using filtration and aeration, which increase sound levels. To assess the effects of laboratory rearing conditions, one group of zebrafish (Danio rerio) embryos (``controls'') were placed into aerated aquaria in a normal laboratory rearing environment. A second set of embryos (``quiet'') were reared in aquaria with no aeration or filtration in a sound-resistant room. The intensity difference between the two sets of tanks was over 30 dB. Preliminary data show that there was no affect of differential rearing environments on saccular hair cell numbers or on hearing ability in fish up to 25 mm total length. However, rearing environment did affect neuromast number. ``Quiet'' fish had higher numbers of both cephalic and trunk superficial neuromasts, relative to controls. This difference was maintained up to 11 mm total length (the size at which canal formation begins). This suggests that acoustic environments normally found in the laboratory do not affect development of hearing in zebrafish, although laboratory acoustics may affect mechanosensory development.

  18. A Retrospective Study of the Prevalence and Classification of Intestinal Neoplasia in Zebrafish (Danio Rerio)

    PubMed Central

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

    2013-01-01

    Abstract 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. PMID:23544991

  19. 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

  20. Effects of Alcohol on Inhibitory Avoidance Learning in Zebrafish (Danio rerio).

    PubMed

    Amorim, Ricardo Rodrigues; Silva, Priscila Fernandes; Luchiari, Ana Carolina

    2017-10-01

    The zebrafish (Danio rerio) can be used in studies addressing the effects of drugs on learning, memory, and anxiety. In the present study, we investigated the effect of different alcohol treatments (chronic and acute) on the learning and anxiety response of zebrafish in an inhibitory avoidance paradigm. Zebrafish were initially exposed to different alcohol treatments and submitted to an inhibitory avoidance protocol, where an electroshock was applied to the fish as they swam from the white to the black side of a shuttle box tank (naturally preferred environment of zebrafish). Animals from the control and 0.5% acute alcohol groups exhibited high latency to enter the black side of the tank after the first exposure to electroshock, in addition to higher freezing and a shorter distance from the bottom of the tank, suggesting acute alcohol exposure did not affect aversive learning in zebrafish. However, chronic exposure and alcohol withdrawal impaired the fish's capacity to properly respond to the aversive stimulus. Overall, our results show the harmful effects of chronic alcohol exposure, both continued intake and its cessation, but avoidance behavior persisted and anxiety increased following acute alcohol exposure.

  1. 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.

  2. 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

  3. 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

  4. The morphology and mechanical sensitivity of lateral line receptors in zebrafish larvae (Danio rerio).

    PubMed

    Van Trump, William J; McHenry, Matthew J

    2008-07-01

    The lateral line system of fish and amphibians detects water flow with receptors on the surface of the body. Although differences in the shape of these receptors, called neuromasts, are known to influence their mechanics, it is unclear how neuromast morphology affects the sensitivity of the lateral line system. We examined the functional consequences of morphological variation by measuring the dimensions of superficial neuromasts in zebrafish larvae (Danio rerio) and mathematically modeling their mechanics. These measurements used a novel morphometric technique that recorded landmarks in three dimensions at a microscopic scale. The mathematical model predicted mechanical sensitivity as the ratio of neuromast deflection to flow velocity for a range of stimulus frequencies. These predictions suggest that variation in morphology within this species generates a greater than 30-fold range in the amplitude of sensitivity and more than a 200-fold range of variation in cut-off frequency. Most of this variation was generated by differences in neuromast height that do not correlate with body position. Our results suggest that natural variation in cupular height within a species is capable of generating large differences in their mechanical filtering and dynamic range.

  5. Animal Personality Relates to Thermal Preference in Wild-Type Zebrafish, Danio rerio.

    PubMed

    Rey, Sonia; Digka, Nikoletta; MacKenzie, Simon

    2015-06-01

    It has been widely supported that individual animals express different strategies to cope with environmental challenge. In ectothermic species such as fish, individuals must use behavioral thermoregulation mechanisms to optimize physiological performance. In the present study, thermal preference was tested in groups of wild-type zebrafish, Danio rerio, screened for proactive and reactive animal personalities. Three replicate groups of proactive, reactive, and naive randomly sampled non-screened controls were used for the experiments. The frequency distribution of the animals was recorded in a custom-built multichamber tank under both constant temperature (temperature restricted conditions: TR) and a continuous thermal gradient profile (temperature choice: TCh ranging from 21°C to 35°C). Proactive and reactive animal personalities expressed significantly different thermal preferences and general activity within the temperature gradient. Our results show that proactive fish, generally characterized as being more aggressive, bold risk takers, and prone to routine formation, have a preference for higher temperature environments. Reactive fish, which are shy, less risk-prone, and more flexible, favor medium colder temperatures. This is the first report of thermopreferendum in zebrafish where individual animal personality coupled to freedom of thermal choice has been applied to understand variation in individual preferences within a population.

  6. 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

  7. Dimethyl sulfoxide (DMSO) exacerbates cisplatin-induced sensory hair cell death in zebrafish (Danio rerio).

    PubMed

    Uribe, Phillip M; Mueller, Melissa A; Gleichman, Julia S; Kramer, Matthew D; Wang, Qi; Sibrian-Vazquez, Martha; Strongin, Robert M; Steyger, Peter S; Cotanche, Douglas A; Matsui, Jonathan I

    2013-01-01

    Inner ear sensory hair cells die following exposure to aminoglycoside antibiotics or chemotherapeutics like cisplatin, leading to permanent auditory and/or balance deficits in humans. Zebrafish (Danio rerio) are used to study drug-induced sensory hair cell death since their hair cells are similar in structure and function to those found in humans. We developed a cisplatin dose-response curve using a transgenic line of zebrafish that expresses membrane-targeted green fluorescent protein under the control of the Brn3c promoter/enhancer. Recently, several small molecule screens have been conducted using zebrafish to identify potential pharmacological agents that could be used to protect sensory hair cells in the presence of ototoxic drugs. Dimethyl sulfoxide (DMSO) is typically used as a solvent for many pharmacological agents in sensory hair cell cytotoxicity assays. Serendipitously, we found that DMSO potentiated the effects of cisplatin and killed more sensory hair cells than treatment with cisplatin alone. Yet, DMSO alone did not kill hair cells. We did not observe the synergistic effects of DMSO with the ototoxic aminoglycoside antibiotic neomycin. Cisplatin treatment with other commonly used organic solvents (i.e. ethanol, methanol, and polyethylene glycol 400) also did not result in increased cell death compared to cisplatin treatment alone. Thus, caution should be exercised when interpreting data generated from small molecule screens since many compounds are dissolved in DMSO.

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

    PubMed Central

    Garcia, Rachel L; Sanders, George E

    2011-01-01

    Appropriate cleaning and disinfection procedures in zebrafish (Danio rerio) laboratories are crucial in preventing the spread of aquatic animal pathogens and minimizing the build-up of waste products and biologic matter. The procedures selected should accomplish these goals and incorporate the individual needs of various laboratories. In this study of a single zebrafish facility, we assessed the efficacy of 2 different cleaning and disinfection procedures for nets, tanks, and lids. ATP levels were used as a surrogate biomarker for microbial burden. We measured the number of relative light units (RLU), as an expression of the amount of ATP present, on items before and after disinfection and calculated the percentage reduction. We compared daily replacement of a commercial net disinfection product in J lab with weekly replacement in H lab and found a 96.6% reduction in RLU in H lab and a 91.2% reduction in J lab. These results indicate that either replacement schedule is effective. Evaluation of tanks and lids soaked in a bleach disinfection bath for 30 or 60 min revealed a 99.7% reduction in RLU at 30 min compared with 97.1% at 60 min. Therefore a 30-min soak in a bleach bath achieved a similar level of disinfection as did a 60-min soak. The current results demonstrate that these cleaning and disinfection methods are efficacious. PMID:22330783

  9. 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

  10. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. 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

  12. Effects of gamma radiation on the early developmental stages of Zebrafish (Danio rerio).

    PubMed

    Praveen Kumar, M K; Shyama, S K; Kashif, Shamim; Dubey, S K; Avelyno, D'costa; Sonaye, B H; Kadam Samit, B; Chaubey, R C

    2017-08-01

    The zebrafish is gaining importance as a popular vertebrate model organism and is widely employed in ecotoxicological studies, especially for the biomonitoring of pollution in water bodies. There is limited data on the genetic mechanisms governing the adverse health effects in regards to an early developmental exposure to gamma radiation. In the present study zebrafish (Danio rerio) embryos were exposed to 1, 2.5, 5, 7.5 and 10Gy of gamma radiation at 3h post fertilization (hpf). Different developmental toxicity endpoints were investigated. Further, expression of genes associated with the development and DNA damage i.e. (sox2 sox19a and p53) were evaluated using Quantitative PCR (qPCR). The significant changes in the expression of sox2 sox19a and p53 genes were observed. This data was supported the developmental defects observed in the zebrafish embryo exposed to gamma radiation such as i.e. increased DNA damage, decreased hatching rate, increase in median hatching time, decreased body length, increased mortality rate, increased morphological deformities. Further, study shows that the potential ecotoxicological threat of gamma radiation on the early developmental stages of zebrafish. Further, it revealed that the above parameters can be used as predictive biomarkers of gamma radiation exposure. Copyright © 2017. Published by Elsevier Inc.

  13. 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.

  14. Acute toxicity of ionic liquids for three freshwater organisms: Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio.

    PubMed

    Pretti, Carlo; Chiappe, Cinzia; Baldetti, Ilaria; Brunini, Sara; Monni, Gianfranca; Intorre, Luigi

    2009-05-01

    The static acute toxicities of 18 ionic liquids (ILs) were determined for three representative freshwater organisms, the cladoceran Daphnia magna, the green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum), and the fish Danio rerio (formerly known as zebrafish). The test kit compounds contained three widely used ILs (1-butyl-3-methylimidazolium bis(triflimide), [bmim][Tf(2)N], butylpyridinium bis(triflimide), [bpy][Tf(2)N], and N,N-methylbutylpyrrolidinium bis(triflimide), [bmpyrr][Tf(2)N]) and 15 less common salts. These latter comprised a range of five anions, four positively charged head groups (ammonium, morpholinium, thiophenium, and sulfonium), five 1-methyl-3-alkyl imidazolium derivatives bearing a specific functional group on the longer alkyl chain (Cl, OH, or (CH(3))(3)Si) and three imidazolium derivatives characterized by the presence of a hydrogen atom on the imidazolium nitrogen ("Brønsted acidic imidazolium"-based ILs). Generally, long-chain ammonium salts showed higher toxicity to algae, cladocerans, and fish, whereas very low toxicities characterized sulfonium- and morpholinium-based ILs. In imidazolium-based ILs, the substitution of one or two carbon atoms of the longer alkyl chain with a more electronegative atom (chlorine or oxygen) reduced the acute toxicity for algae and cladocerans. Low toxicity also characterized the "Brønsted acidic imidazolium"-based ILs. Structural information for a rational designer of safer ILs can be obtained from these studies.

  15. Behavioral and Proteomic Analysis of Stress Response in Zebrafish (Danio rerio)

    PubMed Central

    2015-01-01

    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. PMID:25398274