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Sample records for adult japanese medaka

  1. Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station

    PubMed Central

    Murata, Yasuhiko; Yasuda, Takako; Watanabe-Asaka, Tomomi; Oda, Shoji; Mantoku, Akiko; Takeyama, Kazuhiro; Chatani, Masahiro; Kudo, Akira; Uchida, Satoko; Suzuki, Hiromi; Tanigaki, Fumiaki; Shirakawa, Masaki; Fujisawa, Koichi; Hamamoto, Yoshihiko; Terai, Shuji; Mitani, Hiroshi

    2015-01-01

    To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment (“Medaka Osteoclast”) was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation–reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation. PMID:26427061

  2. Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station.

    PubMed

    Murata, Yasuhiko; Yasuda, Takako; Watanabe-Asaka, Tomomi; Oda, Shoji; Mantoku, Akiko; Takeyama, Kazuhiro; Chatani, Masahiro; Kudo, Akira; Uchida, Satoko; Suzuki, Hiromi; Tanigaki, Fumiaki; Shirakawa, Masaki; Fujisawa, Koichi; Hamamoto, Yoshihiko; Terai, Shuji; Mitani, Hiroshi

    2015-01-01

    To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment ("Medaka Osteoclast") was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation-reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation. PMID:26427061

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

    PubMed

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

    2014-06-01

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

  4. 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...

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

    SciTech Connect

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

    1990-01-01

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

  6. 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...

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

    USGS Publications Warehouse

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

    2014-01-01

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

  8. 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. PMID:26096885

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

    PubMed Central

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

    2010-01-01

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

  10. Diethylstilbestrol at environmental levels affects the development of early life stage and target gene expression in Japanese Medaka (Oryzias latipes).

    PubMed

    Lei, Bingli; Peng, Wei; Li, Wei; Yu, Yingxin; Xu, Jie; Wang, Yipei

    2016-04-01

    In this study, the biologic effects of DES on the early life and adult life stages of Japanese medaka (Oryzias latipes) were evaluated. At the early life stage, the fertilized eggs were exposed to 1-1000 ng/L diethylstilbestrol (DES) for 15 days and the hatched larvae were continually exposed to the same concentrations for an additional 25 days. Significant adverse effects on hatchability, time to hatching and mortality rate occurred at DES concentrations of 100 and 1000 ng/L, while the abnormality (scoliosis and abdominal swelling) rate was significantly increased at 10 ng/L and above. After exposure, the fish were maintained in charcoal-dechlorinated tap water for a further 30 days. Only the male gonadosomatic index (GSI) at 1000 ng/L was significantly increased. At concentrations greater than 1 ng/L, estrogen receptor α (ERα) mRNA in both sexes and vitellogenin-I (Vtg-I) mRNA in males were significantly down-regulated; while Vtg-I mRNA in females was significantly up-regulated. When sexually mature medaka were exposed to 10 and 1000 ng/L DES for 21 days, only the GSI in females was significantly decreased at 1000 ng/L. At 10 and 1000 ng/L, ERα mRNA in both sexes was significantly down-regulated, while Vtg-I mRNA in males was significantly up-regulated. These findings showed that DES at the environmental concentration of 10 ng/L can affect the early life stage development of medaka and alter liver ERα and Vtg-I gene expression. Therefore, if we only focused on these sensitive toxicity endpoints such as ERα and Vtg-I mRNA expression, DES has a strong estrogenic effect on Japanese medaka. PMID:26908245

  11. 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...

  12. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA

    EPA Science Inventory

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equivalent exposures of 17-b-estradiol (E2) and a solvent control (ethanol: EtOH). Japanese medaka were exposed for 4 days to a nominal concentration of 20 ?g/l of either NP-I (Schenectad...

  13. REPRODUCTION AND DEVELOPMENT OF JAPANESE MEDAKA FOLLOWING AN EARLY LIFE STAGE EXPOSURE TO XENOESTROGENS (R823450)

    EPA Science Inventory

    Japanese medaka were exposed to environmentally-relevant concentrations of environmental estrogens: nonylphenol (NP, 0.5, 0.8 and 1.9 g l-1), methoxychlor (MXC, 0.2, 0.6 and 2.3 g...

  14. 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...

  15. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA. (R827098)

    EPA Science Inventory

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equalivent exposures of 17--estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nomina...

  16. Developmental and morphological studies in Japanese medaka with ultra-high resolution optical coherence tomography

    PubMed Central

    Gladys, Fanny Moses; Matsuda, Masaru; Lim, Yiheng; Jackin, Boaz Jessie; Imai, Takuto; Otani, Yukitoshi; Yatagai, Toyohiko; Cense, Barry

    2015-01-01

    We propose ultra-high resolution optical coherence tomography to study the morphological development of internal organs in medaka fish in the post-embryonic stages at micrometer resolution. Different stages of Japanese medaka were imaged after hatching in vivo with an axial resolution of 2.8 µm in tissue. Various morphological structures and organs identified in the OCT images were then compared with the histology. Due to the medaka’s close resemblance to vertebrates, including humans, these morphological features play an important role in morphogenesis and can be used to study diseases that also occur in humans. PMID:25780725

  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. Expression of mep50 in adult and embryos of medaka fish (Oryzias latipes).

    PubMed

    Cheng, Nana; Guo, Maomao; Chang, Pei; Zhang, Xueyan; Zhang, Runshuai; Qi, Chao; Zhong, Xueping; Zhou, Qingchun; Zhao, Haobin

    2016-06-01

    Protein arginine methylation is important for gene regulation and biological processes. Methylosome protein 50 (Mep50) is identified as a partner of protein arginine methyltransferase 5 (Prmt5), a major enzyme capable of symmetric dimethylation, in mammals and Xenopus. The isolation and characterization of medaka mep50 were reported in this paper. Medaka Mep50 is a homolog of human MEP50 with six WD40 domains. Medaka mep50 was ubiquitously expressed in the adult tissues and had maternal origin with continuous and dynamical expression during embryonic development detected by RT-PCR and in situ hybridization. A strong interaction of medaka Mep50 and Prmt5 was shown by yeast two hybridization. The expression pattern of mep50 is similar to that of prmt5 in medaka. The results suggested that medaka Mep50 could be a partner of Prmt5 and might play major roles in a variety of tissues in medaka. PMID:26749004

  19. Sharing the Roles: An Assessment of Japanese Medaka Estrogen Receptors in Vitellogenin Induction.

    PubMed

    Lee Pow, Crystal S D; Yost, Erin E; Aday, D Derek; Kullman, Seth W

    2016-08-16

    Teleost fish express at least three estrogen receptor (ER) subtypes. To date, however, the individual role of these ER subtypes in regulating expression of estrogen responsive genes remains ambiguous. Here, we investigate putative roles of three ER subtypes in Japanese medaka (Oryzias latipes), using vitellogenin (VTG) I and II as model genes. We identify specific ligand/receptor/promoter dynamics, using transient transactivation assays that incorporate luciferase reporters comprising 3kb promoter/enhancer regions of medaka VTGI and VTGII genes. Four steroidal estrogens (17β-estradiol, estrone, estriol, and 17α-estradiol) were tested in these assays. Results indicate that all three medaka ERs (mERs) are capable of initiating transactivation of both VTG I and II, with ERβ2 exhibiting greatest activity. Promoter deletion analysis suggests that ligand-specific receptor transactivation and utilization of regional-specific estrogen response elements may be associated with differential activities of each medaka ER. Further, cluster analysis of in vivo gene expression and in vitro transactivation suggests that all three ER subtypes putatively play a role in up-regulation of VTG. Results illustrate that preferential ligand/receptor/promoter interactions may have direct implications for VTG gene expression and other ER-mediated regulatory functions that are relevant to the risk assessment of estrogenic compounds. PMID:27391190

  20. Stage susceptibility of Japanese medaka (Oryzias latipes) to selenomethionine and hypersaline developmental toxicity.

    PubMed

    Kupsco, Allison; Schlenk, Daniel

    2016-05-01

    Anthropogenic disturbance of seleniferous soils can lead to selenium contamination of waterways. Although selenium is an essential micronutrient, bioaccumulation and maternal transfer of proteinaceous selenomethionine (SeMet) can result in embryo toxicity. Furthermore, as the climate changes, the salinity of spawning grounds in water-restrained estuaries is increasing. Although a small increase in salinity may not directly impact adult fish, it may alter the detoxification strategies of developing organisms. Previous research indicates that hypersalinity may potentiate SeMet embryo toxicity at an early developmental stage. However, embryonic development is a complex, spatiotemporal process with a constantly shifting cellular microenvironment. To generate thresholds and an adverse outcome pathway for the interactions between selenium and salinity, we sought to identify windows of susceptibility for lethality and deformities in the Japanese medaka (Oryzias latipes). Embryos were treated in freshwater or saltwater for 24 h with 0.5 µM, 5 µM, and 50 µM SeMet at 6 different developmental stages (9, 17, 25, 29, 34, and 38). Survival, hatch, deformities (total, type, and severity), and days to hatch were quantified. Selenium embryo tissue measurements were performed. Selenomethionine exposures of 5 µM and 50 µM significantly decreased survival and hatch at all stages. However, SeMet uptake was stage-dependent and increased with stage. Stage 17 (early neurulation) was identified as the most susceptible stage for lethality and deformities. Selenomethionine in saltwater caused significantly greater toxicity than freshwater at stage 25 (early organogenesis), suggesting a role for liver and osmoregulatory organogenesis in toxicity. Environ Toxicol Chem 2016;35:1247-1256. © 2015 SETAC. PMID:26442765

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

    PubMed

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

    2011-02-01

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

  2. TRANSGENERATIONAL EXPOSURE TO TRENBOLONE IN JAPANESE MEDAKA: IN OVO VERSUS HATCHLING EXPOSURE SETAC 22 ANNUAL MEETING, BALTIMORE, MD NOVEMBER 11-15, 2001

    EPA Science Inventory

    . Transgenerational Exposure to Trenbolone in Japanese Medaka: In Ovo Versus Hatchling Exposure (Abstract). To be presented at the 22nd Annual Meeting of the Society of Environmental Toxicology and Chemistry: Changing Environmental Awareness: Societal Concerns and Scientific Resp...

  3. Diluted bitumen causes deformities and molecular responses indicative of oxidative stress in Japanese medaka embryos.

    PubMed

    Madison, Barry N; Hodson, P V; Langlois, V S

    2015-08-01

    This study characterized the toxicity and physiological effects of unweathered diluted bitumen (Access Western Blend dilbit; AWB) to fish. Embryos of Japanese medaka (Oryzias latipes) were exposed for 17 days to dilutions of physically-dispersed (water accommodated fraction; WAF) and chemically-dispersed (chemically-enhanced WAF; CEWAF) dilbit. AWB dilbit exposure was not lethal to medaka, but resulted in a high prevalence of blue sac disease (BSD), impaired development, and abnormal or un-inflated swim bladders at hatch. Physiological effects were indicated by the relative mRNA levels of key genes associated with, among others, cell cycling and the response to mutations (p53), xenobiotic metabolism (ahr, arnt2), phase I (cyp1a) and II processes associated with oxidative stress (cat, g6pdh, hsp70, gst, gpx, gsr, nfe2, and sod). AWB dilbit treatment increased p53 and cyp1a transcript levels (1.5-fold and >15-fold, respectively), with significant, but less pronounced changes in indicators of oxidative stress and metabolism. The exposure-related changes in embryotoxicity and mRNA synthesis were consistent with metabolism of polycyclic aromatic hydrocarbons (PAHs) to reactive and toxic metabolites. Medaka embryos responded similarly to WAF and CEWAF treatments, but CEWAF was about 100 times more efficient in delivering toxic concentrations of PAHs. The toxicity of chemically-dispersed nujol, a non-toxic mineral oil used as an experimental control, suggested that a portion of the observed effects of AWB could be attributed to excess dispersant in solution. This first study of the physiological effects of dilbit toxicity to fish embryos provides a baseline to compare toxicity between dilbit and conventional crude oils, and the groundwork for the development of molecular biomarkers of the sensitivity and level of risk of native Canadian fish species to dilbit exposure. PMID:26118968

  4. Functional dynamics of claudin expression in Japanese medaka (Oryzias latipes): Response to environmental salinity.

    PubMed

    Bossus, Maryline C; Madsen, Steffen S; Tipsmark, Christian K

    2015-09-01

    Salinity regulation of 13 claudin paralogs was investigated in osmoregulatory organs of euryhaline Japanese medaka. They were identified by blast-search in the medaka genome database based on representation in osmoregulatory organs of other teleosts. Our hypothesis was that, because of their sequence similarities to mammalian orthologs previously characterized as barrier- and ion-selective channel-forming proteins, these paralogs would respond to salinity according to expected modulation of osmoregulatory function. Cldn10c, -10d, -10e, -10f, -27a, -28a, -28b and -30c had 4- to 100-fold higher expression in gill than other examined organs. Two splice variants of cldn10b were predominantly expressed in kidney, while cldn15a, -15b and -25 were found mainly in intestine. In gills, cldn27a, -28a, -28b and -30c did not change between fresh water (FW) and seawater (SW)-acclimated fish, while cldn10c, -10d, -10e, and -10f were most abundant in SW. Short-term SW transfer induced up-regulation of cldn10 gill paralogs after 1 day, decrease in cldn28b and no difference for cldn27a, -28a and -30c. The reverse pattern was observed after FW transfer of SW medaka. Intestinal cldn15a and -25 did not differ between FW and SW fish. However, cldn15b was 10-fold higher in FW than SW, suggesting a role in functional modulation of the intestine related to water and salt transport. In kidney, cldn10bs were elevated in SW fish, suggesting a role in paracellular ion transport in the marine nephron. Based on in silico analysis, most gill Cldn10s were predicted to form cation pores, whereas Cldn27a, 28a, 28b and 30c may increase epithelial resistance. PMID:25957710

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

    PubMed

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

    2003-01-01

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

  6. 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. PMID:25175354

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

    PubMed

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

    2008-01-01

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

  8. Does Japanese medaka (Oryzias latipes) exhibit a gill Na(+)/K(+)-ATPase isoform switch during salinity change?

    PubMed

    Bollinger, Rebecca J; Madsen, Steffen S; Bossus, Maryline C; Tipsmark, Christian K

    2016-05-01

    Some euryhaline teleosts exhibit a switch in gill Na(+)/K(+)-ATPase (Nka) α isoform when moving between fresh water (FW) and seawater (SW). The present study tested the hypothesis that a similar mechanism is present in Japanese medaka and whether salinity affects ouabain, Mg(2+), Na(+) and K(+) affinity of the gill enzyme. Phylogenetic analysis classified six separate medaka Nka α isoforms (α1a, α1b, α1c, α2, α3a and α3b). Medaka acclimated long-term (>30 days) to either FW or SW had similar gill expression of α1c, α2, α3a and α3b, while both α1a and α1b were elevated in SW. Since a potential isoform shift may rely on early changes in transcript abundance, we conducted two short-term (1-3 days) salinity transfer experiments. FW to SW acclimation induced an elevation of α1b and α1a after 1 and 3 days. SW to FW acclimation reduced α1b after 3 days with no other α isoforms affected. To verify that the responses were typical, additional transport proteins were examined. Gill ncc and nhe3 expression were elevated in FW, while cftr and nkcc1a were up-regulated in SW. This is in accordance with putative roles in ion-uptake and secretion. SW-acclimated medaka had higher gill Nka V max and lower apparent K m for Na(+) compared to FW fish, while apparent affinities for K(+), Mg(2+) and ouabain were unchanged. The present study showed that the Japanese medaka does not exhibit a salinity-induced α isoform switch and therefore suggests that Na(+) affinity changes involve altered posttranslational modification or intermolecular interactions. PMID:26920794

  9. Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka

    PubMed Central

    Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

    2015-01-01

    Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. PMID:26511497

  10. Genetic Architecture of the Variation in Male-Specific Ossified Processes on the Anal Fins of Japanese Medaka.

    PubMed

    Kawajiri, Maiko; Fujimoto, Shingo; Yoshida, Kohta; Yamahira, Kazunori; Kitano, Jun

    2015-12-01

    Traits involved in reproduction evolve rapidly and show great diversity among closely related species. However, the genetic mechanisms that underlie the diversification of courtship traits are mostly unknown. Japanese medaka fishes (Oryzias latipes) use anal fins to attract females and to grasp females during courtship; the males have longer anal fins with male-specific ossified papillary processes on the fin rays. However, anal fin morphology varies between populations: the southern populations tend to have longer anal fins and more processes than the northern populations. In the present study, we conducted quantitative trait locus (QTL) mapping to investigate the genetic architecture underlying the variation in the number of papillary processes of Japanese medaka fish and compared the QTL with previously identified QTL controlling anal fin length. First, we found that only a few QTL were shared between anal fin length and papillary process number. Second, we found that the numbers of papillary processes on different fin rays often were controlled by different QTL. Finally, we produced another independent cross and found that some QTL were repeatable between the two crosses, whereas others were specific to only one cross. These results suggest that variation in the number of papillary processes is polygenic and controlled by QTL that are distinct from those controlling anal fin length. Thus, different courtship traits in Japanese medaka share a small number of QTL and have the potential for independent evolution. PMID:26511497

  11. Teratogenic effects of azaspiracid-1 identified by microinjection of Japanese medaka (Oryzias latipes) embryos.

    PubMed

    Colman, Jamie R; Twiner, Michael J; Hess, Philipp; McMahon, Terry; Satake, Masayuki; Yasumoto, Takeshi; Doucette, Gregory J; Ramsdell, John S

    2005-06-01

    Azaspiracid-1 (AZA-1) is a newly identified phycotoxin that accumulates in commercially important bivalve molluscs harvested in several European countries and causes severe human intoxications. Molluscan shellfish are known vectors for accumulation and subsequent transfer of phycotoxins such as brevetoxin and domoic acid through various trophic levels within food webs. Finfish can also accumulate phycotoxins, both directly from toxic algae or from consumption of contaminated shellfish and smaller intoxicated fish. To evaluate the teratogenic potential of AZA-1 and its relevancy to toxin accumulation in finfish, we have utilized a microinjection technique to mimic the maternal-egg toxin transfer of an AZA-1 reference standard and a shellfish extract containing azaspiracids in an embryonic Japanese medaka (Oryzias latipes) fish model. Microinjection of purified AZA-1 caused dose-dependent effects on heart rate, developmental rate, hatching success, and viability in medaka embryos. Within 4 days of exposure to doses > or = 40 pg AZA-1/egg, substantial retardation in development was observed as reduced somatic growth and yolk absorption, and delayed onset of blood circulation and pigmentation. Embryos treated to > or =40 pg AZA-1/egg had slower heart rates (bradycardia) for the 9 days in ovo period, followed by reduced hatching success. Microinjection of a contaminated mussel (Mytilus edulis) extract containing AZAs (AZA-1, -2, and -3), okadaic acid, and dinophysistoxin-2 resulted in similar responses from the fish embryos at equivalent doses. These studies demonstrate that AZA-1 is a potent teratogen to finfish. This work will complement future investigations on AZA-1 accumulation in marine food webs and provide a basis for understanding its toxicity at different trophic levels. PMID:15904683

  12. 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.

  13. 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.

  14. 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

  15. Equol Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with 17β-Estradiol.

    PubMed

    Wang, Chen; Zhang, Shiyi; Zhou, Yuyin; Huang, Chong; Mu, Di; Giesy, John P; Hu, Jianying

    2016-07-19

    Equol is present in the aquatic environment via livestock waste and runoff discharge; however, it remains unclear whether it can induce gonadal intersex in fish at environmentally relevant concentrations. This study evaluated adverse effects of equol on gonadal development by exposing transgenic Japanese medaka (Oryzias latipes) from hatching for 100 days. Equol induced intersex incidence in male medaka in a dose-dependent manner, and the benchmark dose corresponding to 10% intersex incidence (BMD10) was 11.5 ng/L (95% confidence interval (CI): 5.8 ng/L, 19.8 ng/L), which was comparable to the required dose of 17β-estradiol (E2β) (9.0 ng/L, 95% CI: 6.6 ng/L, 11.0 ng/L). Equol exposure resulted in reduced plasma 11-ketotestosterone (11-KT) concentrations in male medaka at 1.3 ng/L, while reduced plasma 11-KT concentrations were observed at a relatively high concentration (6.4 ng/L) of E2β. Such antiandrogenic property could partly explain the comparable potency of equol with that of E2β to induce intersex at relatively low concentrations, although the binding affinity of equol to medaka estrogen receptor α (EC50 939.4 nM) was 230-fold lower than that (4.07 nM) of E2β. This study for the first time demonstrated that equol could induce intersex in medaka fish at environmentally relevant concentrations. PMID:27305592

  16. Biomarker responses and reproductive toxicity of the effluent from a Chinese large sewage treatment plant in Japanese medaka (Oryzias latipes).

    PubMed

    Ma, Taowu; Wan, Xiaoqiong; Huang, Qinghui; Wang, Zijian; Liu, Jiankang

    2005-04-01

    The present study was conducted to assess the potential toxicity of the effluent from a large sewage treatment plant (GBD-STP) in Beijing. Japanese medakas (Oryzias latipes) at reproduction active period were exposed to a serial of graded concentrations of the effluent or 100 ng l-1 of 17-alpha-ethinylestradiol (EE2, positive control). Growth, gonadosomatic index (GSI), hepatosomatic index (HSI), reproductive success, induction potency of vitellogenin (VTG) in male fish and that of 7-ethoxyresorufin-o-deethylase activity (EROD) in male fish liver were used as test endpoints. The growth suppression of fish was observed in a dose-dependent manner, resulting in significant differences in both body length and body weight of medaka above 5% effluent. This effluent can inhibit the growth of gonad of medakas and are more sensitive to male than to female. At exposure concentration of 40% and higher, there was an unexpected decrease of HSI values, which may be resulted from sub-lethal toxicity of effluent to fish liver. VTG of plasma in males were induced in all exposure concentration levels, but not in a dose-dependent manner. The concentration of 5% effluent would be the lowest observed adverse effect level (LOAEL) affecting reproductive success when examining fertile individuals, fecundity and fertilization rate. The overt CYP1A response and higher reproductive toxicity may be indicative of low process efficiency of this STP. PMID:15722100

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

    PubMed

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

    2016-09-01

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

  18. Two farnesoid X receptor alpha isoforms in Japanese medaka (Oryzias latipes) are differentially activated in vitro

    PubMed Central

    Howarth, Deanna L.; Hagey, Lee R.; Law, Sheran H.W.; Ai, Ni; Krasowski, Matthew D.; Ekins, Sean; Moore, John T.; Kollitz, Erin M.; Hinton, David E.; Kullman, Seth W.

    2010-01-01

    The nuclear receptor farnesoid X receptor alpha (FXRα, NR1H4) is activated by bile acids in multiple species including mouse, rat, and human and in this study we have identified two isoforms of Fxrα in Japanese medaka (Oryzias latipes), a small freshwater teleost. Both isoforms share a high amino acid sequence identity to mammalian FXRα (~70% in the ligand-binding domain). Fxrα1 and Fxrα2 differ within the AF1 domain due to alternative splicing at the fourth intron-exon boundary. This process results in Fxrα1 having an extended N-terminus compared to Fxrα2. A Gal4DBD-FxrαLBD fusion construct was activated by chenodeoxycholic, cholic, deoxycholic and lithocholic acids, and the synthetic agonist GW4064 in transient transactivation assays. Activation of the Gal4DBD-FxrαLBD fusion construct was enhanced by addition of PGC-1α, as demonstrated through titration assays. Surprisingly, when the full-length versions of the two Fxrα isoforms were compared in transient transfection assays, Fxrα2 was activated by C24 bile acids and GW4064, while Fxrα1 was not significantly activated by any of the compounds tested. Since the only significant difference between the full-length constructs was sequence in the AF1 domain, these experiments highlight a key functional region in the Fxrα AF1 domain. Furthermore, mammalian two-hybrid studies demonstrated the ability of Fxrα2, but not Fxrα1, to interact with PGC-1α and SRC-1, and supported our results from the transient transfection reporter gene activation assays. These data demonstrate that both mammalian and teleost FXR (Fxrα2 isoform) are activated by primary and secondary bile acids. PMID:20430454

  19. 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

  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). PMID:27162070

  1. Use of Medaka in Toxicity Testing

    PubMed Central

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

    2015-01-01

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

  2. Developmental toxicity of PAH mixtures in fish early life stages. Part II: adverse effects in Japanese medaka.

    PubMed

    Le Bihanic, Florane; Clérandeau, Christelle; Le Menach, Karyn; Morin, Bénédicte; Budzinski, Hélène; Cousin, Xavier; Cachot, Jérôme

    2014-12-01

    In aquatic environments, polycyclic aromatic hydrocarbons (PAHs) mostly occur as complex mixtures, for which risk assessment remains problematic. To better understand the effects of PAH mixture toxicity on fish early life stages, this study compared the developmental toxicity of three PAH complex mixtures. These mixtures were extracted from a PAH-contaminated sediment (Seine estuary, France) and two oils (Arabian Light and Erika). For each fraction, artificial sediment was spiked at three different environmental concentrations roughly equivalent to 0.5, 4, and 10 μg total PAH g(-1) dw. Japanese medaka embryos were incubated on these PAH-spiked sediments throughout their development, right up until hatching. Several endpoints were recorded at different developmental stages, including acute endpoints, morphological abnormalities, larvae locomotion, and genotoxicity (comet and micronucleus assays). The three PAH fractions delayed hatching, induced developmental abnormalities, disrupted larvae swimming activity, and damaged DNA at environmental concentrations. Differences in toxicity levels, likely related to differences in PAH proportions, were highlighted between fractions. The Arabian Light and Erika petrogenic fractions, containing a high proportion of alkylated PAHs and low molecular weight PAHs, were more toxic to Japanese medaka early life stages than the pyrolytic fraction. This was not supported by the toxic equivalency approach, which appeared unsuitable for assessing the toxicity of the three PAH fractions to fish early life stages. This study highlights the potential risks posed by environmental mixtures of alkylated and low molecular weight PAHs to early stages of fish development. PMID:24595754

  3. 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...

  4. Boule Is Present in Fish and Bisexually Expressed in Adult and Embryonic Germ Cells of Medaka

    PubMed Central

    Xu, Hongyan; Li, Zhendong; Li, Mingyou; Wang, Li; Hong, Yunhan

    2009-01-01

    Background The DAZ family genes boule, daz and dazl encode RNA binding proteins essential for fertility of diverse animals including human. dazl has bisexual expression in both mitotic and meiotic germ cells, whereas daz has male premeiotic expression, and boule is largely a unisexual meiotic regulator. Although boule has been proposed as the ancestor for dazl/daz by gene duplication, it has been identified only in invertebrates and mammals. It has, however, remained unclear when and how the DAZ family has evolved in vertebrates. Methodology and Principal Findings This study was aimed at identifying and characterizing the DAZ family genes in fish as the basal vertebrate. We show that boule and dazl coexist in medaka and stickleback. Similar to the medaka dazl (Odazl), the medaka boule (Obol) is maternally supplied and segregates with primordial germ cells. Surprisingly, Obol is expressed in adult germ cells at pre-meiotic and meiotic stages of spermatogenesis and oogenesis. However, the maximal meiotic Obol expression in spermatocytes contrasts with the predominant pre-meiotic Odazl expression in spermatogonia, and the diffuse cytoplasmic Obol distribution in early oocytes contrasts with the Odazl concentration in the Balbinani's body. Conclusions The identification of fish boule and dazl genes provides direct evidence for the early gene duplication during vertebrate evolution. Our finding that Obol exhibits bisexual expression in both embryonic and adult germ cells considerably extends the diversity of boule expression patterns and offers a new insight into the evolutions of DAZ family members, expression patterns and functions in animal fertility. PMID:19564913

  5. Arginine vasotocin neuronal development and its projection in the adult brain of the medaka.

    PubMed

    Kagawa, Nao; Honda, Akira; Zenno, Akiko; Omoto, Ryosuke; Imanaka, Saya; Takehana, Yusuke; Naruse, Kiyoshi

    2016-02-01

    The neurohypophysial peptide arginine vasotocin (AVT) and its mammalian ortholog arginine vasopressin function in a wide range of physiological and behavioral events. Here, we generated a new line of transgenic medaka (Oryzias latipes), which allowed us to monitor AVT neurons by enhanced green fluorescent protein (EGFP) and demonstrate AVT neuronal development in the embryo and the projection of AVT neurons in the adult brain of avt-egfp transgenic medaka. The onset of AVT expression manifested at 2 days postfertilization (dpf) as a pair of signals in the telencephalon of the brain. The telencephalic AVT neurons migrated and converged on the preoptic area (POA) by 4dpf. At the same stage, another onset of AVT expression manifested in the central optic tectum (OT), and they migrated to the ventral part of the hypothalamus (VH) by 6dpf. In the adult brain, the AVT somata with EGFP signals existed in the gigantocellular POA (gPOA), magnocellular POA (mPOA), and parvocellular POA (pPOA) and in the VH. Whereas the major projection of AVT fibers was found from the pPOA and VH to the posterior pituitary, it was also found that AVT neurons in the three POAs send their fibers into wide regions of the brain such as the telencephalon, mesencephalon and diencephalon. This study suggests that the avt-egfp transgenic medaka is a useful model to explore AVT neuronal development and function. PMID:26739197

  6. 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. PMID:27203565

  7. 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

  8. 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. PMID:21658359

  9. 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.

  10. Environmental concentrations of benz[a]anthracene induce developmental defects and DNA damage and impair photomotor response in Japanese medaka larvae.

    PubMed

    Le Bihanic, Florane; Sommard, Vivien; Perrine, de Lansalut; Pichon, Anaïk; Grasset, Julie; Berrada, Saadia; Budzinski, Hélène; Cousin, Xavier; Morin, Bénédicte; Cachot, Jérôme

    2015-03-01

    Benz[a]anthracene (BaA) is a ubiquitous polycyclic aromatic hydrocarbon found in numerous aquatic ecosystems. However, ecotoxicological data in aquatic organisms are scarce. To remedy this lack of data, Japanese medaka (Oryzias latipes) embryos were exposed to BaA and toxic effects were investigated at multiple toxicological endpoints. Japanese medaka embryos were incubated onto BaA-spiked artificial sediment for 9 days at low or moderate environmental concentrations ranging from 0.9 to 12 µgg(-1) dw. BaA-exposed embryos exhibited significant tachycardia. BaA exposure was also shown to increase CYP1A activity in the hepato-biliary tissue as well as craniofacial deformities and DNA damage in pro-larvae. The photomotor response of BaA-exposed larvae was reduced in comparison to the control group. According to this set of tests, the lowest tested and observed effect concentration (LOEC) for Japanese medaka early life stages was equivalent to 0.92 µgg(-1) dw of BaA. This concentration fall into the range of concentrations frequently encountered in sediments of polluted aquatic ecosystems. Taking into consideration these results, BaA represents a threat for fish early life stages in particular those developing onto or into contaminated sediments. PMID:25528488

  11. Effects of the brominated flame retardant TBCO on fecundity and profiles of transcripts of the HPGL-axis in Japanese medaka.

    PubMed

    Saunders, David M V; Podaima, Michelle; Wiseman, Steve; Giesy, John P

    2015-03-01

    The novel brominated flame retardant, 1,2,5,6-tetrabromocyclooctane (TBCO) is an additive flame retardant which is marketed under the trade name Saytex BCL-48. TBCO has recently been investigated as a potential alternative to the major use brominated flame retardant, hexabromocyclododecane (HBCD), which could have major implications for significant increases in amounts of TBCO used. Yet there is a lack of information regarding potential toxicities of TBCO. Recently, results of in vitro experiments have demonstrated the potential of TBCO to modulate endocrine function through interaction with estrogen and androgen receptors and via alterations to the synthesis of 17-β-estradiol and testosterone. Further research is required to determine potential endocrine disrupting effects of TBCO in vivo. In this experiment a 21-day fecundity assay with Japanese medaka (Oryzias latipes) was conducted to examine endocrine disrupting effects of TBCO in vivo. Medaka were fed a diet containing either 607 or 58μg TBCO/g food, wet mass (wm). Fecundity, measured as cumulative deposition of eggs and fertilization of eggs, as well as abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were measured as indicators of holistic endocrine disruption and to determine mechanisms of effects, respectively. Cumulative fecundity was 18% lesser by medaka exposed to 58μg TBCO/g, wm food. However, fecundity of medaka exposed to 607μg TBCO/g, wm food was not significantly different from that of controls. Organ-specific and dose-dependent alterations to abundances of transcripts were observed in male and female medaka. A pattern of down-regulation of expression of genes involved in steroidogenesis, metabolism of cholesterol, and regulatory feedback mechanisms was observed in gonads from male and female medaka which had been exposed to the greater concentration of TBCO. However, these effects on expression of genes were not manifested in effects on

  12. oct4-EGFP reporter gene expression marks the stem cells in embryonic development and in adult gonads of transgenic medaka.

    PubMed

    Froschauer, Alexander; Khatun, Mst Muslima; Sprott, David; Franz, Alexander; Rieger, Christiane; Pfennig, Frank; Gutzeit, Herwig O

    2013-01-01

    Maintenance of pluripotency in stem cells is tightly regulated among vertebrates. One of the key genes in this process is oct4, also referred to as pou5f1 in mammals and pou2 in teleosts. Pou5f1 evolved by duplication of pou2 early in the tetrapod lineage, but only monotremes and marsupials retained both genes. Either pou2 or pou5f1 was lost from the genomes of the other tetrapods that have been analyzed to date. Consequently, these two homologous genes are often designated oct4 in functional studies. In most vertebrates oct4 is expressed in pluripotent cells of the early embryo until the blastula stage, and later persist in germline stem cells until adulthood. The isolation and analysis of stem cells from embryo or adult individuals is hampered by the need for reliable markers that can identify and define the cell populations. Here, we report the faithful expression of EGFP under the control of endogenous pou2/oct4 promoters in transgenic medaka (Oryzias latipes). In vivo imaging in oct4-EGFP transgenic medaka reveals the temporal and spatial expression of pou2 in embryos and adults alike. We describe the temporal and spatial patterns of endogenous pou2 and oct4-EGFP expression in medaka with respect to germline and adult stem cells, and discuss applications of oct4-EGFP transgenic medaka in reproductive and stem cell biology. PMID:23139203

  13. 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. PMID:26395355

  14. 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. PMID:24777665

  15. 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

  16. A mixture of the novel brominated flame retardants TBPH and TBB affects fecundity and transcript profiles of the HPGL-axis in Japanese medaka.

    PubMed

    Saunders, David M V; Podaima, Michelle; Codling, Garry; Giesy, John P; Wiseman, Steve

    2015-01-01

    The novel brominated flame retardants (NBFRs), bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) and 2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB) are components of the flame retardant mixture Firemaster 550 and both TBPH and TBB have recently been listed as high production volume chemicals by the US EPA. These NBFRs have been detected in several environmental matrices but very little is known about their toxic effects or potencies. Results of in vitro assays demonstrated potentials of these NBFRs to modulate endocrine function through interactions with estrogen (ER) and androgen receptors (AR) and via alterations to synthesis of 17-β-estradiol (E2) and testosterone (T), but in vivo effects of these chemicals on organisms are not known. Therefore a 21-day short term fish fecundity assay with Japanese medaka (Oryzias latipes) was conducted to investigate if these NBFRs affect endocrine function in vivo. Medaka were fed a diet containing either 1422 TBPH:1474 TBB or 138:144 μg/g food, wet weight (w/w). Cumulative production of eggs was used as a measure of fecundity and abundances of transcripts of 34 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were quantified to determine mechanisms of observed effects. Cumulative fecundity was impaired by 32% in medaka exposed to the greatest dose of the mixture of TBPH/TBB. A pattern of global down-regulation of gene transcription at all levels of the HPGL axis was observed, but effects were sex-specific. In female medaka the abundance of transcripts of ERβ was lesser in livers, while abundances of transcripts of VTG II and CHG H were greater. In male medaka, abundances of transcripts of ERα, ERβ, and ARα were lesser in gonads and abundances of transcripts of ERβ and ARα were lesser in brain. Abundances of transcripts of genes encoding proteins for synthesis of cholesterol (HMGR), transport of cholesterol (HDLR), and sex hormone steroidogenesis (CYP 17 and 3β-HSD) were significantly lesser in male

  17. 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.

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

    EPA Science Inventory

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

  19. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach

    PubMed Central

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-01-01

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

  20. Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach.

    PubMed

    Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-01-01

    Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

  1. 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.

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

    PubMed

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

    2016-07-19

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

  3. Adult perceptions of phonotactic violations in Japanese

    NASA Astrophysics Data System (ADS)

    Fais, Laurel; Kajikawa, Sachiyo; Werker, Janet; Amano, Shigeaki

    2001-05-01

    Adult Japanese speakers ``hear'' epenthetic vowels in productions of Japanese-like words that violate the canonical CVCVCV form by containing internal consonant clusters (CVCCV) [Dupoux et al., J. Exp. Psychol. 25, 1568-1578 (1999)]. Given this finding, this research examined how Japanese adults rated the goodness of Japanese-like words produced without a vowel in the final syllable (CVC), and words produced without vowels in the penultimate and final syllables (CVCC). Furthermore, in some of these contexts, voiceless vowels may appear in fluent, casual Japanese productions, especially in the Kanto dialect, and in some, such voiceless vowels may not appear. Results indicate that both Kanto and Kinki speakers rated CVC productions for contexts in which voiceless vowels are not allowed as the worst; they rated CVC and CVCC contexts in which voiceless vowel productions are allowed as better. In these latter contexts, the CVC words, which result from the loss of one, final, vowel, are judged to be better than the CVCC words, which result from the loss of two (final and penultimate) vowels. These results mirror the relative seriousness of the phonotactic violations and indicate listeners have tacit knowledge of these regularities in their language.

  4. Light and electron microscopic analyses of Vasa expression in adult germ cells of the fish medaka.

    PubMed

    Yuan, Yongming; Li, Mingyou; Hong, Yunhan

    2014-07-15

    Germ cells of diverse animal species have a unique membrane-less organelle called germ plasm (GP). GP is usually associated with mitochondria and contains RNA binding proteins and mRNAs of germ genes such as vasa. GP has been described as the mitochondrial cloud (MC), intermitochondrial cement (IC) and chromatoid body (CB). The mechanism underlying varying GP structures has remained incompletely understood. Here we report the analysis of GP through light and electron microscopy by using Vasa as a marker in adult male germ cells of the fish medaka (Oryzias latipes). Immunofluorescence light microscopy revealed germ cell-specific Vasa expression. Vasa is the most abundant in mitotic germ cells (oogonia and spermatogonia) and reduced in meiotic germ cells. Vasa in round spermatids exist as a spherical structure reminiscent of CB. Nanogold immunoelectron microscopy revealed subcellular Vasa redistribution in male germ cells. Vasa in spermatogonia concentrates in small areas of the cytoplasm and is surrounded by mitochondria, which is reminiscent of MC. Vasa is intermixed with mitochondria to form IC in primary spermatocytes, appears as the free cement (FC) via separation from mitochondria in secondary spermatocyte and becomes condensed in CB at the caudal pole of round spermatids. During spermatid morphogenesis, Vasa redistributes and forms a second CB that is a ring-like structure surrounding the dense fiber of the flagellum in the midpiece. These structures resemble those described for GP in various species. Thus, Vasa identifies GP and adopts varying structures via dynamic reorganization at different stages of germ cell development. PMID:24814190

  5. Effects of prolonged exposure to low pH on enzymatic and non-enzymatic antioxidants in Japanese Medaka (Oryzias latipes).

    PubMed

    Ramírez-Duarte, Wilson F; Jin, Jiali; Kurobe, Tomofumi; Teh, Swee J

    2016-10-15

    Acidification in aquatic ecosystems is a major concern worldwide. In freshwater, although there are several publications reporting acute toxicity and adverse effects due to low pH, little is known about adverse effects on antioxidant mechanisms in fish after prolonged exposure. This study aimed to investigate how antioxidants are affected by raising larval Japanese Medaka (Oryzias latipes) in soft water at pH5.5, 6.0, and 6.5. After 18days of exposure, glutathione concentration and glutathione peroxidase activity in whole body homogenates increased as pH decreased, without changes in lipid peroxidation measured as thiobarbituric acid reactive substances. This study showed that prolonged exposure to low pH increased reactive oxygen species production and that fish cope with it by increasing levels of enzymatic and non-enzymatic antioxidants. PMID:27285793

  6. 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

  7. 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

  8. GUIDELINES FOR THE CULTURE OF THE MEDAKA, ORYZIAS LATIPES

    EPA Science Inventory

    This paper describes culture techniques for producing large numbers of all life stages of Japanese medaka, Oryzias latipes for use in biological research. he biology of the medaka is described as it relates to culturing practices and the physical systems used to maintain a large ...

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

    PubMed

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

    2015-08-01

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

  10. 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, D.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.

  11. Transcriptional responses and embryotoxic effects induced by pyrene and methylpyrene in Japanese medaka (Oryzias latipes) early life stages exposed to spiked sediments.

    PubMed

    Barjhoux, Iris; Cachot, Jérôme; Gonzalez, Patrice; Budzinski, Hélène; Le Menach, Karyn; Landi, Laure; Morin, Bénédicte; Baudrimont, Magalie

    2014-12-01

    Japanese medaka (Oryzias latipes) embryos were exposed to sediments spiked with environmental concentrations (300 and 3,000 ng/g dry weight) of pyrene (Pyr) and methylpyrene (MePyr) throughout their development. Embryotoxicity, teratogenicity, and transcriptional responses (qRT-PCR) were analyzed in embryos and newly hatched larvae. The genotoxicity of the two polycyclic aromatic hydrocarbons (PAHs) was also tested in prolarvae using the comet assay. Exposure to each compound had a clear impact on embryonic development and resulted in several teratogenic effects, including cardiovascular injuries, reduced absorption of yolk sac reserves, and jaw and spinal deformities. Interestingly, the overall toxic effects of Pyr and MePyr considerably overlapped those induced following dioxin exposure. qRT-PCR analysis revealed the transcriptional induction of genes involved in mitochondrial energetic metabolism (coxI), xenobiotic biotransformation (cyp1a), and cell cycle regulation (wnt1) by the two PAHs. MePyr also activated cell cycle arrest (p53), oxidative DNA damage repair (ogg1), and retinoid-mediated (raldh2 and rarα1) gene transcription. DNA damage was not found to be significantly increased following Pyr and MePyr exposure. The lack of significant genotoxic effect in comparison to the control might be the consequence of the efficient onset of DNA damage repair mechanisms as suggested by ogg1 gene transcription upregulation. Results reported in the present study have brought new insights into the modes of action of Pyr, and the effects of MePyr exposure have been investigated in fish ELS for the first time. PMID:24756688

  12. 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.

  13. CARCINOMA OF THE EXOCRINE PANCREAS IN MEDAKA

    EPA Science Inventory

    Eight cases of acinar cell carcinoma of the exocrine pancreas were diagnosed in Japanese medaka (Oryzias latipes) from a pool of approximately 10,000 specimens used in a variety of carcinogenesis bioassays. hree cases occurred in specimens from control groups and one case in a sp...

  14. Sensivity of Adult Reproduction and Reproductive Development in Japanese Medaka Exposed to 4-Tert-octylphenol

    EPA Science Inventory

    In response to legislation, the USEPA is developing assessment tools for identifying chemicals likely to cause sublethal effects on reproduction and reproductive development with ultimate adverse impacts on fish populations. While fecundity and fertility data from short-term adul...

  15. Older Japanese Adults and Mobile Phones: An Applied Ethnographic Study

    ERIC Educational Resources Information Center

    Hachiya, Kumiko

    2010-01-01

    This qualitative research investigates the meaning of "keitai" (mobile phones) for older Japanese adults between the ages of 59 and 79. Participants' emails from keitai, handwritten daily logs, and audio and video recordings from meetings and interviews were collected during my stay of nearly seven months in one of the largest cities in Japan.…

  16. 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 ...

  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, P.S.M.; Noltie, D.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. Literacy to Aurality/Orality in an Adult Japanese ESL Student: A Case Study.

    ERIC Educational Resources Information Center

    Biro, Jan E.

    A study examined the factors shaping English language education within the Japanese public education system and the attitudes of Japanese learners toward the pronunciation of English, first in an overview and then within the context of a case study of an adult Japanese student. The first section discusses the status and instruction of English in…

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

    PubMed

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

    2015-04-01

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

  20. 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

  1. Low dose exposure to Bisphenol A alters development of gonadotropin-releasing hormone 3 neurons and larval locomotor behavior in Japanese Medaka.

    PubMed

    Inagaki, T; Smith, N; Lee, E K; Ramakrishnan, S

    2016-01-01

    Accumulating evidence indicates that chronic low dose exposure to Bisphenol A (BPA), an endocrine disruptor, may disrupt normal brain development and behavior mediated by the gonadotropin-releasing hormone (GnRH) pathways. While it is known that GnRH neurons in the hypothalamus regulate reproductive physiology and behavior, functional roles of extra-hypothalamic GnRH neurons remain unclear. Furthermore, little is known whether BPA interacts with extra-hypothalamic GnRH3 neural systems in vulnerable developing brains. Here we examined the impact of low dose BPA exposure on the developing GnRH3 neural system, eye and brain growth, and locomotor activity in transgenic medaka embryos and larvae with GnRH3 neurons tagged with GFP. Fertilized eggs were collected daily and embryos/larvae were chronically exposed to 200ng/ml of BPA, starting at 1 day post fertilization (dpf). BPA significantly increased fluorescence intensity of the GnRH3-GFP neural population in the terminal nerve (TN) of the forebrain at 3dpf, but decreased the intensity at 5dpf, compared with controls. BPA advanced eye pigmentation without affecting eye and brain size development, and accelerated times to hatch. Following chronic BPA exposure, 20dpf larvae showed suppression of locomotion, both in distance covered and speed of movement (47% and 43% reduction, respectively). BPA-induced hypoactivity was accompanied by decreased cell body sizes of individual TN-GnRH3 neurons (14% smaller than those of controls), but not of non-GnRH3 neurons. These novel data demonstrate complex neurobehavioral effects of BPA on the development of extra-hypothalamic GnRH3 neurons in teleost fish. PMID:26687398

  2. Serum Albumin Levels and Economic Status in Japanese Older Adults

    PubMed Central

    Ota, Asami; Kondo, Naoki; Murayama, Nobuko; Tanabe, Naohito; Shobugawa, Yugo; Kondo, Katsunori

    2016-01-01

    Background Low serum albumin levels are associated with aging and medical conditions such as cancer, liver dysfunction, inflammation, and malnutrition and might be an independent predictor of long-term mortality in healthy older populations. We tested the hypothesis that economic status is associated with serum albumin levels and explained by nutritional and health status in Japanese older adults. Design We performed a cross-sectional analysis using data from the Japan Gerontological Evaluation study (JAGES). The study participants were 6528 functionally independent residents (3189 men and 3339 women) aged ≥65 years living in four municipalities in Aichi prefecture. We used household income as an indicator of economic status. Multiple linear regression was used to compare serum albumin levels in relation to household income, which was classified as low, middle, and high. Additionally, mediation by nutritional and health-related factors was analyzed in multivariable models. Results With the middle-income group as reference, participants with low incomes had a significantly lower serum albumin level, even after adjustment for sex, age, residential area, education, marital status, and household structure. The estimated mean difference was −0.17 g/L (95% confidence interval, −0.33 to −0.01 g/L). The relation between serum albumin level and low income became statistically insignificant when “body mass index”, “consumption of meat or fish”, “self-rated health”, “presence of medical conditions”, “hyperlipidemia”, or “respiratory disease “was included in the model. Conclusion Serum albumin levels were lower in Japanese older adults with low economic status. The decrease in albumin levels appears to be mediated by nutrition and health-related factors with low household incomes. Future studies are needed to reveal the existence of other pathways. PMID:27276092

  3. Japanese Adult Learners' Development of the Locality Condition on English Reflexives.

    ERIC Educational Resources Information Center

    Akiyama, Yasuhiro

    2002-01-01

    Explores the developmental patterns observed when Japanese adult learners acquire the locality condition on English reflexives. Experimental tasks were designed specifically to deal with the methodological problems of earlier research and then administered to Japanese learners of English at five proficiency levels as well as English and Japanese…

  4. I Think, Therefore, I Improve: A Qualitative Study of Concepts of "Hansei (Introspection) among Japanese Adults

    ERIC Educational Resources Information Center

    Taylor, Satomi Izumi; Wang, L. Weiping; Ogawa, Tetsuya

    2005-01-01

    The purpose of this study was to examine the concept of "hansei" (introspection) among teachers, parents, and other relatives of Japanese kindergarteners. The data came from essays written by Japanese adults. The data analysis revealed that the concept of "hansei" encompassed self-evaluation, improvement, and morality. The implications for…

  5. Histopathology of a wavy medaka

    PubMed Central

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

    2016-01-01

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

  6. Cognitive Impairment and Disability in Older Japanese Adults

    PubMed Central

    Shimada, Hiroyuki; Makizako, Hyuma; Doi, Takehiko; Tsutsumimoto, Kota; Lee, Sangyoon; Suzuki, Takao

    2016-01-01

    The prevalence of disability is increasing due to an expanding aging population and an increasing incidence of chronic health problems. Cognitive impairment may predict the development of disability in older adults. Therefore, we examined the association of mild cognitive impairment (MCI) and/or general cognitive impairment (GCI, defined as a Mini Mental State Examination [MMSE] score of 20–23) with the development of disability in a cohort of Japanese community-dwelling older adults. A total of 4290 participants (aged ≥65 years) enrolled in the Obu Study of Health Promotion for the Elderly were classified according to the presence and degree of cognitive impairment as follows: cognitively healthy, GCI, MCI single domain (MCIs), MCIs with GCI, MCI multiple domain (MCIm), and MCIm with GCI. MMSE scores, risk factors for dementia, and incidences of new disability were recorded. After an average of 29.5 months, 205 participants (4.8%) experienced a new onset of disability. All subtypes of cognitive impairment showed significant relationships with disability except for GCI alone. The following hazard ratios (HRs) were determined: MCIs (HR, 2.04; 95% CI, 1.39–3.00), MCIs with GCI (HR, 2.10; 95% CI, 1.21–3.62), MCIm (HR, 2.32; 95% CI, 1.39–3.85), and MCIm with GCI (HR, 4.23; 95% CI, 2.73–6.57). These results indicate that cognitive impairment may be related to an increased risk for the development of disability. Healthcare providers should implement global cognitive assessments to identify MCI and GCI and consider preventive interventions for disability, especially in older persons. PMID:27415430

  7. Implications of "Amae" for HIV Risk in Japanese Young Adults.

    ERIC Educational Resources Information Center

    Onuoha, Francis N.; Munakata, Tsunetsugu

    2005-01-01

    Assertiveness, defined as perceived confidence to express true feelings in interpersonal relationships, has been reported to correlate with HIV risk avoidance. However, Japanese social structure encourages "amae" or self-repression. The present study investigated the implications of "amae" for HIV risk avoidance among Japanese university students.…

  8. Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

    PubMed

    Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

    2016-09-01

    Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. PMID:26823140

  9. Development of the Fish Medaka in Microgravity

    NASA Technical Reports Server (NTRS)

    Wolgemuth, Debra J.

    1995-01-01

    The goal of these experiments was to determine the effect of microgravity on the early development of the fish medaka. There were two objectives for this flight series. The primary objective was to assess the effects of microgravity on different stages of development and to ascertain whether the relevant developmental questions can be addressed at the gross morphological level or if the issues involve more subtle questions about regulation at the molecular and cellular levels. The secondary objective was the assessment of the utility of flight hardware with the capabilities to perform embryological studies. We have been able to take advantage of the flight testing phase of the STL-B hardware to also study the effects of microgravity on the early development of the fish, Medaka. Our initial studies involved monitoring the early Medaka development and raising flight embryos for breeding. Images of the developing embryos were collected either via video which was either taken by the astronauts or broadcast to Earth. Sample video images were digitized and stored on a hard drive resident within the on-board STL-B unit. Embryos were fixed at specific intervals, returned to Earth and are being analyzed for the timing and location of molecular events associated with controlling the morphological pattern for the onset of adult structures.

  10. Intonation Facilitates Contrast Resolution: Evidence from Japanese Adults and 6-Year Olds

    ERIC Educational Resources Information Center

    Ito, Kiwako; Jincho, Nobuyuki; Minai, Utako; Yamane, Naoto; Mazuka, Reiko

    2012-01-01

    Two eye-tracking experiments tested how pitch prominence on a prenominal adjective affects contrast resolution in Japanese adult and 6-year old listeners. Participants located two animals in succession on displays with multiple colored animals. In Experiment 1, adults' fixations to the contrastive target (pink cat [right arrow] GREEN cat) were…

  11. Differences in dentofacial characteristics of Class I malocclusion between Saudi and Japanese adult females

    PubMed Central

    Abbassy, Mona A; Abushal, Amal

    2015-01-01

    Objectives: The objective was to compare dentofacial characteristics of Class I malocclusion in Saudi and Japanese adult females. Materials and Methods: Lateral cephalograms of 50 Saudi adult female and 50 Japanese adult female (18–35-year-old) were obtained. All patients were skeletal Class I, angle Class I malocclusion, arch length discrepancy (−10–10 mm), overjet (1–5 mm), overbite (1–5 mm), absence of congenital anomalies, or significant facial asymmetries or congenitally missing tooth other than the 3rd molar and absence of temporomandibular joint problems. Patient cephalograms were traced and digitized. 16 angular measurements and 13 linear measurements of facial form were used. Results: A comparison of the vertical dimension showed that the Saudi females had a significantly larger gonial angle, a significantly larger facial angle and longer lower face height compared to the Japanese females. Dentally, Saudi females had more protruded incisors with increased distances of the posterior teeth to the palatal plane. For the soft tissue dimension, the Saudi subjects had a significantly more prominent nose, retruded lip and a more protruded chin compared with Japanese. Conclusions: There were significant differences in dentofacial morphology between Saudi and Japanese adult females. Both Asian countries have distinct cephalometric features, which should be considered as a reference in treating patients of varying ethnic backgrounds to optimize the final results. PMID:26229950

  12. Development of a Japanese Quality of Life Instrument for Older Adults Experiencing Dementia (QLDJ)

    ERIC Educational Resources Information Center

    Yamamoto-Mitani, Noriko; Abe, Toshiko; Okita, Yuko; Hayashi, Kunihiko; Sugishita, Chieko; Kamata, Keiko

    2002-01-01

    This study develops a quality of life instrument for older Japanese people experiencing dementia (QLDJ). Quality of life (QL) for these older adults is defined as a three dimensional construct including 1) interacting with surroundings, 2) expressing self, and 3) experiencing minimum negative behaviors. From 53 items in the initial item pool, 24…

  13. Dynamic Processes of Speech Development by Seven Adult Learners of Japanese in a Domestic Immersion Context

    ERIC Educational Resources Information Center

    Fukuda, Makiko

    2014-01-01

    The present study revealed the dynamic process of speech development in a domestic immersion program by seven adult beginning learners of Japanese. The speech data were analyzed with fluency, accuracy, and complexity measurements at group, interindividual, and intraindividual levels. The results revealed the complex nature of language development…

  14. Syntax in a Native Language Still Continues to Develop in Adults: Honorification Judgment in Japanese

    ERIC Educational Resources Information Center

    Momo, Kanako; Sakai, Hiromu; Sakai, Kuniyoshi L.

    2008-01-01

    Native languages (L1s) are tacitly assumed to be complete and stable in adults. Here we report an unexpected individual variation in judgment of L1 regarding Japanese sentences including honorification, and further clarify its neural basis with functional magnetic resonance imaging (fMRI). By contrasting an honorification judgment task with a…

  15. Japanese Children's and Adults' Reasoning about the Consequences of Psychogenic Bodily Reactions

    ERIC Educational Resources Information Center

    Toyama, Noriko

    2011-01-01

    Four experiments were conducted with Japanese children and adult participants to assess their awareness of the effectiveness of biological and psychological treatments for psychogenic bodily reactions. Study 1 had 116 participants, composed of 4-year-olds (17), 5-year-olds (20), 7-year-olds (24), 10-year-olds (20), and college students (35). The…

  16. The Politics of Time and Space in Japanese Adult Basic Education

    ERIC Educational Resources Information Center

    Jacobson, Erik

    2015-01-01

    This qualitative study examines critical pedagogy in Japanese adult basic education. The research focuses on what teachers and others think the current conditions are for education that deals with social justice. As part of this, the research looks at how critical pedagogy is conceptualized in this context. Participants in the study (literacy…

  17. Community Building as an Instructional Goal in Japanese Adult Basic Education

    ERIC Educational Resources Information Center

    Jacobson, Erik

    2009-01-01

    This paper presents the results of a multisite case study of adult basic education in Japan. A key finding of the study is that as part of community building within classrooms, students, teachers, and administrators prioritize human relations and expressions of empathy rather than academic skill development. In contrast to Japanese educational…

  18. [Developing the Japanese version of the Adult Attachment Style Scale (ECR)].

    PubMed

    Nakao, Tatsuma; Kato, Kazuo

    2004-06-01

    This study attempted to adapt into Japanese the Adult Attachment Style Scale (ECR: Experiences in Close Relationships inventory) that was constructed by Brennan, Clark, and Shaver (1998), based on 14 existing scales. Of 387 respondents, 231 who reported having been or are currently involved in romantic relationships were employed for final analysis. We examined validities of the Japanese version of ECR in the two ways: (1) Examining the correlations between "Anxiety" and Self-esteem scale by Rosenberg (1965) which were theoretically related to Self-view, and the correlations between "Avoidance" and Other-view scale by Kato (1999b) which were theoretically related to Other-view; (2) whether or not ECR represents the features of four attachment styles as classified by Relationship Questionnaire (RQ; Bartholomew & Horowitz, 1991). The results supported our expectations. This Japanese version of ECR was demonstrated to have adequate psychometric properties in validity and reliability. PMID:15747547

  19. Genomic and Phenotypic Characterization of a Wild Medaka Population: Towards the Establishment of an Isogenic Population Genetic Resource in Fish

    PubMed Central

    Spivakov, Mikhail; Auer, Thomas O.; Peravali, Ravindra; Dunham, Ian; Dolle, Dirk; Fujiyama, Asao; Toyoda, Atsushi; Aizu, Tomoyuki; Minakuchi, Yohei; Loosli, Felix; Naruse, Kiyoshi; Birney, Ewan; Wittbrodt, Joachim

    2014-01-01

    Oryzias latipes (medaka) has been established as a vertebrate genetic model for more than a century and recently has been rediscovered outside its native Japan. The power of new sequencing methods now makes it possible to reinvigorate medaka genetics, in particular by establishing a near-isogenic panel derived from a single wild population. Here we characterize the genomes of wild medaka catches obtained from a single Southern Japanese population in Kiyosu as a precursor for the establishment of a near-isogenic panel of wild lines. The population is free of significant detrimental population structure and has advantageous linkage disequilibrium properties suitable for the establishment of the proposed panel. Analysis of morphometric traits in five representative inbred strains suggests phenotypic mapping will be feasible in the panel. In addition, high-throughput genome sequencing of these medaka strains confirms their evolutionary relationships on lines of geographic separation and provides further evidence that there has been little significant interbreeding between the Southern and Northern medaka population since the Southern/Northern population split. The sequence data suggest that the Southern Japanese medaka existed as a larger older population that went through a relatively recent bottleneck approximately 10,000 years ago. In addition, we detect patterns of recent positive selection in the Southern population. These data indicate that the genetic structure of the Kiyosu medaka samples is suitable for the establishment of a vertebrate near-isogenic panel and therefore inbreeding of 200 lines based on this population has commenced. Progress of this project can be tracked at http://www.ebi.ac.uk/birney-srv/medaka-ref-panel. PMID:24408034

  20. Japanese macaque (Macaca fuscata) mothers huddle with their young offspring instead of adult females for thermoregulation.

    PubMed

    Ueno, Masataka; Nakamichi, Masayuki

    2016-08-01

    It is unclear whom animals select to huddle with for thermoregulation. In this study, we investigated whom Japanese macaque (Macaca fuscata) mothers huddled with-their young offspring or other adult group members-when there is need for thermoregulation. We used a focal-animal sampling method, targeting 17 females at Katsuyama, Okayama Prefecture, Japan. A majority of huddling among adult females was recorded during winter season (December, January, and February). Females who had young (0- or 1-year-old) offspring huddled less frequently with other adult females compared to females who did not have young offspring in winter. However, including young offspring, the frequency of huddling with any other individuals did not differ by whether females had young offspring. Moreover, the females who did not have young offspring huddled with other adult females more often in cloudy than in sunny weather during winter season. In contrast, females who had young offspring increased huddling with their young offspring in cloudy than in sunny weather, but did not do so with other adult females. This study indicates that Japanese macaque mothers huddle with their young offspring instead of other adult females when there is need for thermoregulation. PMID:27262980

  1. 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

  2. Gender-Specific Toxicological Effects of Chronic Exposure to Pure Microcystin-LR or Complex Microcystis aeruginosa Extracts on Adult Medaka Fish.

    PubMed

    Le Manach, Séverine; Khenfech, Nour; Huet, Hélène; Qiao, Qin; Duval, Charlotte; Marie, Arul; Bolbach, Gérard; Clodic, Gilles; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

    2016-08-01

    Cyanobacterial blooms often occur in freshwater lakes and constitute a potential health risk to human populations, as well as to other organisms. However, their overall and specific implications for the health of aquatic organisms that are chronically and environmentally exposed to cyanobacteria producing hepatotoxins, such as microcystins (MCs), together with other bioactive compounds have still not been clearly established and remain difficult to assess. The medaka fish was chosen as the experimental aquatic model for studying the cellular and molecular toxicological effects on the liver after chronic exposures (28 days) to environmentally relevant concentrations of pure MC-LR, complex extracts of MC producing or nonproducing cyanobacterial biomasses, and of a Microcystis aeruginosa natural bloom. Our results showed a higher susceptibility of females to the different treatments compared to males at both the cellular and the molecular levels. Although hepatocyte lysis increased with MC-containing treatments, lysis always appeared more severe in the liver of females compare to males, and the glycogen cellular reserves also appeared to decrease more in the liver of females compared to those in the males. Proteomic investigations reveal divergent responses between males and females exposed to all treatments, especially for proteins involved in metabolic and homeostasis processes. Our observations also highlighted the dysregulation of proteins involved in oogenesis in female livers. These results suggest that fish populations exposed to cyanobacteria blooms may potentially face several ecotoxicological issues. PMID:27409512

  3. Development of space-fertilized eggs and formation of primordial germ cells in the embryos of medaka fish

    NASA Astrophysics Data System (ADS)

    Ijiri, K.

    In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly `space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

  4. Distinct composition of the oral indigenous microbiota in South Korean and Japanese adults.

    PubMed

    Takeshita, Toru; Matsuo, Kazuki; Furuta, Michiko; Shibata, Yukie; Fukami, Kaoru; Shimazaki, Yoshihiro; Akifusa, Sumio; Han, Dong-Hung; Kim, Hyun-Duck; Yokoyama, Takeshi; Ninomiya, Toshiharu; Kiyohara, Yutaka; Yamashita, Yoshihisa

    2014-01-01

    A comparison of national surveys on oral health suggested that the population of South Korea has a better periodontal health status than that of Japan, despite their similar inherent backgrounds. Here, we investigated differences in oral bacterial assemblages between individuals from those two countries. To exclude potential effects of oral health condition on the microbiota, we selected 52 Korean and 88 Japanese orally healthy adults (aged 40-79 years) from the participants of two cohort studies, the Yangpyeong study in South Korea and the Hisayama study in Japan, and compared the salivary microbiomes. The microbiota of the Japanese individuals comprised a more diverse community, with greater proportions of 17 bacterial genera, including Veillonella, Prevotella, and Fusobacterium, compared to the microbiota of the Korean individuals. Conversely, Neisseria and Haemophilus species were present in much lower proportions in the microbiota of the Japanese individuals than the Korean individuals. Because higher proportions of Prevotella and Veillonella and lower proportions of Neisseria and Haemophilus in the salivary microbiome were implicated in periodontitis, the results of this study suggest that the greater proportion of dysbiotic oral microbiota in the Japanese individuals is associated with their higher susceptibility to periodontitis compared to the Korean individuals. PMID:25384884

  5. Distinct composition of the oral indigenous microbiota in South Korean and Japanese adults

    PubMed Central

    Takeshita, Toru; Matsuo, Kazuki; Furuta, Michiko; Shibata, Yukie; Fukami, Kaoru; Shimazaki, Yoshihiro; Akifusa, Sumio; Han, Dong-Hung; Kim, Hyun-Duck; Yokoyama, Takeshi; Ninomiya, Toshiharu; Kiyohara, Yutaka; Yamashita, Yoshihisa

    2014-01-01

    A comparison of national surveys on oral health suggested that the population of South Korea has a better periodontal health status than that of Japan, despite their similar inherent backgrounds. Here, we investigated differences in oral bacterial assemblages between individuals from those two countries. To exclude potential effects of oral health condition on the microbiota, we selected 52 Korean and 88 Japanese orally healthy adults (aged 40–79 years) from the participants of two cohort studies, the Yangpyeong study in South Korea and the Hisayama study in Japan, and compared the salivary microbiomes. The microbiota of the Japanese individuals comprised a more diverse community, with greater proportions of 17 bacterial genera, including Veillonella, Prevotella, and Fusobacterium, compared to the microbiota of the Korean individuals. Conversely, Neisseria and Haemophilus species were present in much lower proportions in the microbiota of the Japanese individuals than the Korean individuals. Because higher proportions of Prevotella and Veillonella and lower proportions of Neisseria and Haemophilus in the salivary microbiome were implicated in periodontitis, the results of this study suggest that the greater proportion of dysbiotic oral microbiota in the Japanese individuals is associated with their higher susceptibility to periodontitis compared to the Korean individuals. PMID:25384884

  6. Adult headform impact tests of three Japanese child bicycle helmets into a vehicle.

    PubMed

    Mizuno, Koji; Ito, Daisuke; Yoshida, Ryoichi; Masuda, Hiroyuki; Okada, Hiroshi; Nomura, Mitsunori; Fujii, Chikayo

    2014-12-01

    The head is the body region that most frequently incurs fatal and serious injuries of cyclists in collisions against vehicles. Many research studies investigated helmet effectiveness in preventing head injuries using accident data. In this study, the impact attenuation characteristics of three Japanese child bicycle helmets were examined experimentally in impact tests into a concrete surface and a vehicle. A pedestrian adult headform with and without a Japanese child bicycle helmet was dropped onto a concrete surface and then propelled into a vehicle at 35 km/h in various locations such as the bonnet, roof header, windshield and A-pillar. Accelerations were measured and head injury criterion (HIC) calculated. In the drop tests using the adult headform onto a concrete surface from the height of 1.5m, the HIC for a headform without a child helmet was 6325, and was reduced by around 80% when a child helmet was fitted to the headform. In the impact tests, where the headform was fired into the vehicle at 35 km/h at various locations on a car, the computed acceleration based HIC varied depending on the vehicle impact locations. The HIC was reduced by 10-38% for impacts headforms with a child helmet when the impact was onto a bonnet-top and roof header although the HIC was already less than 1000 in impacts with the headform without a child helmet. Similarly, for impacts into the windshield (where a cyclist's head is most frequently impacted), the HIC using the adult headform without a child helmet was 122; whereas when the adult headform was used with a child helmet, a higher HIC value of more than 850 was recorded. But again, the HIC values are below 1000. In impacts into the A-pillar, the HIC was 4816 for a headform without a child helmet and was reduced by 18-38% for a headform with a child helmet depending on the type of Japanese child helmet used. The tests demonstrated that Japanese child helmets are effective in reducing accelerations and HIC in a drop test using

  7. 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

  8. Susceptibility of the Adult Japanese Beetle, Popillia japonica to Entomopathogenic Nematodes

    PubMed Central

    Morris, E. Erin; Grewal, Parwinder S.

    2011-01-01

    To build upon prior research demonstrating the potential of entomopathogenic nematode dissemination by infected adult Japanese beetle, Popillia japonica, we evaluated susceptibility of the adult beetles to 20 strains of Steinernema and Heterorhabditis under laboratory conditions. The nematodes were applied at a rate of 10,000 infective juveniles per 10 adult beetles in 148 mL plastic cups containing autoclaved sand and sassafras leaves as a source of food for the beetles. All strains infected the beetles and caused 55% to 95% mortality. The most virulent strains that caused 50% beetle mortality in less than 5 days included a strain of H. georgiana (D61), three strains of Steinernema sp. (R54, R45, and FC48), and two strains of S. carpocapsae (All and D60). The ability of two strains of Steinernema sp. (R45 and R54) and two strains of Heterorhabditis bacteriophora (D98 and GPS11) to infect and reproduce in the beetle was further examined to assess the potential of infected beetles to disseminate nematodes upon their death. All four strains infected and killed the beetles, but only Steinernema strains reproduced in the cadavers. We conclude that both Heterorhabditis and Steinernema strains are able to cause mortality to adult Japanese beetle, but Steinernema strains may be effectively disseminated due to their reproduction in the beetle. PMID:23431080

  9. Susceptibility of the Adult Japanese Beetle, Popillia japonica to Entomopathogenic Nematodes.

    PubMed

    Morris, E Erin; Grewal, Parwinder S

    2011-09-01

    To build upon prior research demonstrating the potential of entomopathogenic nematode dissemination by infected adult Japanese beetle, Popillia japonica, we evaluated susceptibility of the adult beetles to 20 strains of Steinernema and Heterorhabditis under laboratory conditions. The nematodes were applied at a rate of 10,000 infective juveniles per 10 adult beetles in 148 mL plastic cups containing autoclaved sand and sassafras leaves as a source of food for the beetles. All strains infected the beetles and caused 55% to 95% mortality. The most virulent strains that caused 50% beetle mortality in less than 5 days included a strain of H. georgiana (D61), three strains of Steinernema sp. (R54, R45, and FC48), and two strains of S. carpocapsae (All and D60). The ability of two strains of Steinernema sp. (R45 and R54) and two strains of Heterorhabditis bacteriophora (D98 and GPS11) to infect and reproduce in the beetle was further examined to assess the potential of infected beetles to disseminate nematodes upon their death. All four strains infected and killed the beetles, but only Steinernema strains reproduced in the cadavers. We conclude that both Heterorhabditis and Steinernema strains are able to cause mortality to adult Japanese beetle, but Steinernema strains may be effectively disseminated due to their reproduction in the beetle. PMID:23431080

  10. The Acquisition of /R/ and /L/ by Japanese Children and Adults Learning English as a Second Language.

    ERIC Educational Resources Information Center

    Cochrane, R. McCrae

    1980-01-01

    Describes two experiments to evaluate acquisition of /r/ and /l/ involving native Japanese children and adults residing in the United States. The first required subjects to produce and discriminate English /r/ and /l/ in listening and speaking. Children's performance was better than adults'. In the second, the subject received programed training.…

  11. Sources of strength-training information and strength-training behavior among Japanese older adults.

    PubMed

    Harada, Kazuhiro; Shibata, Ai; Lee, Euna; Oka, Koichiro; Nakamura, Yoshio

    2016-03-01

    The promotion of strength training is now recognized as an important component of public health initiatives for older adults. To develop successful communication strategies to increase strength-training behavior among older adults, the identification of effective communication channels to reach older adults is necessary. This study aimed to identify the information sources about strength training that were associated with strength-training behaviors among Japanese older adults. The participants were 1144 adults (60-74 years old) randomly sampled from the registry of residential addresses. A cross-sectional questionnaire survey was conducted. The independent variables were sources of strength-training information (healthcare providers, friends, families, radio, television, newspapers, newsletters, posters, books, magazines, booklets, the Internet, lectures, other sources), and the dependent variable was regular strength-training behavior. Logistic regression analysis was used to identify potential relationships. After adjusting for demographic factors and all other information sources, strength-training information from healthcare providers, friends, books and the Internet were positively related to regular strength-training behavior. The findings of the present study contribute to a better understanding of strength-training behavior and the means of successful communication directed at increasing strength training among older adults. The results suggest that healthcare providers, friends, books and the Internet are effective methods of communication for increasing strength-training behaviors among older adults. PMID:24997193

  12. A one-year longitudinal study of English and Japanese vowel production by Japanese adults and children in an English-speaking setting

    PubMed Central

    Oh, Grace E.; Guion-Anderson, Susan; Aoyama, Katsura; Flege, James E.; Akahane-Yamada, Reiko; Yamada, Tsuneo

    2011-01-01

    The effect of age of acquisition on first- and second-language vowel production was investigated. Eight English vowels were produced by Native Japanese (NJ) adults and children as well as by age-matched Native English (NE) adults and children. Productions were recorded shortly after the NJ participants’ arrival in the USA and then one year later. In agreement with previous investigations [Aoyama, et al., J. Phon. 32, 233–250 (2004)], children were able to learn more, leading to higher accuracy than adults in a year’s time. Based on the spectral quality and duration comparisons, NJ adults had more accurate production at Time 1, but showed no improvement over time. The NJ children’s productions, however, showed significant differences from the NE children’s for English “new” vowels /ɪ/, /ε/, /ɑ/, /ʌ/ and /ʊ/ at Time 1, but produced all eight vowels in a native-like manner at Time 2. An examination of NJ speakers’ productions of Japanese /i/, /a/, /u/ over time revealed significant changes for the NJ Child Group only. Japanese /i/ and /a/ showed changes in production that can be related to second language (L2) learning. The results suggest that L2 vowel production is affected importantly by age of acquisition and that there is a dynamic interaction, whereby the first and second language vowels affect each other. PMID:21603058

  13. Neurological effects on startle response and escape from predation by medaka exposed to organic chemicals

    SciTech Connect

    Carlson, R.; Drummond, R.; Hammermeister, D.; Bradbury, S.

    1995-12-31

    Simultaneous electrophysiological and behavioral studies were performed on juvenile Japanese medaka (Oryzias latipes) exposed to representative neurotoxic organic chemicals at sublethal concentrations. Non-invasive recordings were made of the electrical impulses generated within giant neuronal Mauthner cells, associated interneurons or motoneurons, and musculature, all of which initiate the startle or escape response in fish. Timing in milliseconds between these electrical sequelae was measured for each fish before and at 24 and 48 hours exposure to a chemical. Also noted was the number of startle responses to number of stimuli ratio (R/S). Other groups of medaka were fed to bluegills and consumption times recorded to assess their ability to escape predation. These results were compared to neurophysiological effect levels. Phenol, 2,4-dinitrophenol, chlorpyrifos, fenvalerate, and 1-octanol impaired the ability of medaka to escape predation at all concentrations. Medaka were more susceptible to predation in high concentrations of carbaryl and strychnine, but less susceptible at low concentrations, whereas the reverse was true for endosulfan. The variety of neurological effects detected at these concentrations suggest that different mechanisms may be responsible. Phenol and strychnine affected Mauthner cell to motoneuron transmission, chlorpyrifos and carbaryl showed neuromuscular effects, and R/S was affected by most chemicals. Although a variety of neurotoxic mechanisms were examined, the exposure threshold for significant effects for each specific compound was found to be consistent for both the neurophysiological and behavioral endpoints.

  14. Swimming behavior of larval Medaka fish under microgravity

    NASA Astrophysics Data System (ADS)

    Furukawa, R.; Ijiri, K.

    Fish exhibit looping and rolling behaviors when subjected to short periods of microgravity during parabolic flight. Strain-differences in the behavioral response of adult Medaka fish ( Oryzias latipes) were reported previously, however, there have been few studies of larval fish behavior under microgravity. In the present study, we investigated whether microgravity affects the swimming behavior of larvae at various ages (0 to 20 days after hatching), using different strains: HNI-II, HO5, ha strain, and variety of different strains (variety). The preliminary experiments were done in the ground laboratory: the development of eyesight was examined using optokinetic response for the different strains. The visual acuity of larvae improved drastically during 20 days after hatching. Strain differences of response were noted for the development of their visual acuity. In microgravity, the results were significantly different from those of adult Medaka. The larval fish appeared to maintain their orientation, except that a few of them exhibited looping and rolling behavior. Further, most larvae swam normally with their backs turning toward the light source (dorsal light response, DLR), and the rest of them stayed with their abdomen touching the surface of the container (ventral substrate response, VSR). For larval stages, strain-differences and age-differences in behavior were observed, but less pronounced than with adult fish under microgravity. Our observations suggest that adaptability of larval fish to the gravitational change and the mechanism of their postural control in microgravity are more variable than in adult fish.

  15. 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...

  16. The Association between Sarcopenic Obesity and Depressive Symptoms in Older Japanese Adults.

    PubMed

    Ishii, Shinya; Chang, Chang; Tanaka, Tomoki; Kuroda, Aki; Tsuji, Tetsuo; Akishita, Masahiro; Iijima, Katsuya

    2016-01-01

    The effects of sarcopenic obesity, the co-existence of sarcopenia and obesity, on mood disorders have not been studies extensively. Our objective was to examine the association of depressive symptoms with sarcopenia and obesity status in older Japanese adults. We analyzed data from 1731 functionally-independent, community-dwelling Japanese adults aged 65 years or older (875 men, 856 women) randomly selected from the resident register of Kashiwa city, Chiba, Japan in 2012. Sarcopenia was defined based on appendicular skeletal muscle mass, grip strength and usual gait speed. Obesity was defined as the highest sex-specific quintile of the percentage body fat. Depressive symptoms were defined as a Geriatric Depression Scale 15-item score ≥ 6. Multiple logistic regression was employed to examine the association of depressive symptoms with four groups defined by the presence/absence of sarcopenia and obesity. The prevalence of depressive symptoms was 10.1% and the proportions of sarcopenia/obesity, sarcopenia/non-obesity, non-sarcopenia/obesity, non-sarcopenia/non-obesity were 3.7%, 13.6%, 16.9% and 65.8%, respectively. After adjustment for potential confounders, sarcopenia/obesity was positively associated with depressive symptoms compared with non-sarcopenia/non-obesity, whereas either sarcopenia or obesity alone was not associated with depressive symptoms. The association was particularly pronounced in those aged 65 to 74 years in age-stratified analysis. We conclude that our findings suggest a synergistic impact exerted by sarcopenic obesity on the risk of depressive symptoms, particularly in those aged 65 to 74 years. PMID:27627756

  17. Seasonal effects of UCP1 gene polymorphism on visceral fat accumulation in Japanese adults.

    PubMed

    Nakayama, Kazuhiro; Miyashita, Hiroshi; Yanagisawa, Yoshiko; Iwamoto, Sadahiko

    2013-01-01

    Uncoupling protein 1 (UCP1) and β3 adrenergic receptor (ADRB3) genes play central roles in the thermogenesis of brown adipose tissue (BAT) in adult humans. However, the importance of single-nucleotide polymorphisms (SNPs) in both genes during the development of obesity is controversial. Although active BAT in adult humans is frequently observed in the winter season, the effects of sampling season have not been taken into consideration in previous association studies. Here, we tested the associations of UCP1 -3826A/G and ADRB3 Trp64Arg with body mass index (BMI) and visceral fat area (VFA) in 3013 Japanese adults sampled during different seasons. Association between SNPs and the obesity-related traits were assessed using multiple linear regression models, including sex, age, physical activity, and genotypes. Both SNPs did not show significant associations in the models based on the entire cohort. However, in subsets comprising individuals mainly sampled from winter to spring, UCP1 showed significant associations with VFA (P = 0.0098) and VFA adjusted for BMI (P = 0.0128). Moreover, the effects of UCP1 on VFA were strongly negatively correlated with outdoor temperature (P = 0.00011), but not with night length (P = 0.039). ADRB3 did not show these associations, but an additive effect with UCP1 was observed for VFA adjusted for BMI (P = 0.0067). Subsets sampled in the hot season did not show significant associations for both SNPs. The season-specific effects of UCP1 on VFA were consistent with a previous finding that active BAT was more frequently found in winter than in summer, and supported the importance of cold stress in BAT activation and the significance of BAT in the development of obesity in adult humans. PMID:24086366

  18. 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.

  19. Chronic fluoxetine treatment induces anxiolytic responses and altered social behaviors in medaka, Oryzias latipes.

    PubMed

    Ansai, Satoshi; Hosokawa, Hiroshi; Maegawa, Shingo; Kinoshita, Masato

    2016-04-15

    Medaka (Oryzias latipes) is a small freshwater teleost that is an emerging model system for neurobehavioral research and toxicological testing. The selective serotonin reuptake inhibitor class of antidepressants such as fluoxetine is one of the widely prescribed drugs, but little is known about the effects of these drugs on medaka behaviors. To assess the behavioral effects of fluoxetine, we chronically administrated fluoxetine to medaka adult fish and analyzed the anxiety-related and social behaviors using five behavioral paradigms (diving, open-field, light-dark transition, mirror-biting, and social interaction) with an automated behavioral testing system. Fish chronically treated with fluoxetine exhibited anxiolytic responses such as an overall increased time spent in the top area in the diving test and an increased time spent in center area in the open-field test. Analysis of socially evoked behavior showed that chronic fluoxetine administration decreased the number of mirror biting times in the mirror-biting test and increased latency to first contact in the social interaction test. Additionally, chronic fluoxetine administration reduced the horizontal locomotor activity in the open-field test but not the vertical activity in the diving test. These investigations are mostly consistent with previous reports in the other teleost species and rodent models. These results indicate that behavioral assessment in medaka adult fish will become useful for screening of effects of pharmaceutical and toxicological compounds in animal behaviors. PMID:26821288

  20. Host suitability and diet mixing influence activities of detoxification enzymes in adult Japanese beetles.

    PubMed

    Adesanya, Adekunle; Liu, Nannan; Held, David W

    2016-05-01

    Induction of cytochrome P450, glutathione S transferase (GST), and carboxylesterase (CoE) activity was measured in guts of the scarab Popillia japonica Newman, after consumption of single or mixed plant diets of previously ranked preferred (rose, Virginia creeper, crape myrtle and sassafras) or non-preferred hosts (boxelder, riverbirch and red oak). The goal of this study was to quantify activities of P450, GST and CoE enzymes in the midgut of adult P. japonica using multiple substrates in response to host plant suitability (preferred host vs non-preferred hosts), and single and mixed diets. Non-preferred hosts were only sparingly fed upon, and as a group induced higher activities of P450, GST and CoE than did preferred hosts. However, enzyme activities for some individual plant species were similar across categories of host suitability. Similarly, beetles tended to have greater enzyme activities after feeding on a mixture of plants compared to a single plant type, but mixing per se does not seem as important as the species represented in the mix. Induction of detoxification enzymes on non-preferred hosts, or when switching between hosts, may explain, in part, the perceived feeding preferences of this polyphagous insect. The potential consequences of induced enzyme activities on the ecology of adult Japanese beetles are discussed. PMID:26964493

  1. Acute neuropsychiatric disorders in adolescents and young adults with Down syndrome: Japanese case reports

    PubMed Central

    Akahoshi, Keiko; Matsuda, Hiroshi; Funahashi, Masuko; Hanaoka, Tomoyuki; Suzuki, Yasuyuki

    2012-01-01

    Background: The aim of this study was to evaluate acute neuropsychiatric disorders in adolescents and young adults with Down syndrome. We report 13 Japanese adolescents or young adults with Down syndrome who developed acute neuropsychiatric disorders including withdrawal, depression, obsessive-compulsive behaviors, and occasional delusions or hallucinations. Methods: The following information was collected from each patient: age at onset of acute neuropsychiatric disorder, complications, signs and symptoms, personality traits before the onset of the acute neuropsychiatric disorder, prescribed medications with their respective doses and the response to treatment, and senile changes observed on magnetic resonance imaging or computed tomography. Results: The mean age at onset of these disorders was 21.2 years. Brain imaging showed almost senile changes; patients responded well to low-dose psychotropic therapy. Patients had an onset at a young age and presented with treatable conditions, although the average age of the onset of Alzheimer’s disease is generally over 40 years of age in patients with Down syndrome. Conclusion: These findings suggest that the pathology of acute neuropsychiatric disorder in patients with Down syndrome may be related to presenile changes; however, these disorders present features and a clinical course that is different from those presented in typical Alzheimer’s disease with Down syndrome. PMID:22888254

  2. Association between Smoking Status and Obesity in a Nationwide Survey of Japanese Adults

    PubMed Central

    Watanabe, Taku; Tsujino, Ichizo; Konno, Satoshi; Ito, Yoichi M.; Takashina, Chisa; Sato, Takahiro; Isada, Akira; Ohira, Hiroshi; Ohtsuka, Yoshinori; Fukutomi, Yuma; Nakamura, Hiroyuki; Kawagishi, Yukio; Okada, Chiharu; Hizawa, Nobuyuki; Taniguchi, Masami; Akasawa, Akira; Nishimura, Masaharu

    2016-01-01

    Objective A positive association between the number of cigarettes smoked per day and obesity has been reported, whereas how other smoking-related indices, such as pack-years and duration of smoking, are related with obesity has been less investigated. We analyzed the age-adjusted cross-sectional association between smoking and obesity in a general Japanese population. Methods We used data from a nationwide epidemiological study of Japanese adults (N = 23,106). We compared the prevalence of obesity (defined as body mass index ≥ 25kg/m2) among groups classified by smoking behavior, pack-years, number of cigarettes per day, duration of smoking, and duration and time of smoking cessation. Results In men, current smokers had a lower odds ratio (OR) for obesity of 0.80 (95% confidence interval (CI): 0.72–0.88) compared to non-smokers, whereas past smokers had a higher OR of 1.23 (95% CI: 1.09–1.37) compared to current smokers. In women, there were no differences in obesity between the three groups classified by smoking behavior. However, in both sexes, the prevalence of obesity tended to increase with pack-years and the number of cigarettes per day, but not with duration of smoking in current and past smokers. Further, in male smokers, the risks for obesity were markedly higher in short-term heavy smokers compared with long-term light smokers, even with the same number of pack-years. Regarding the impact of smoking cessation, female past smokers who quit smoking at an age > 55-years had an elevated OR of 1.60 (95% CI:1.05–2.38) for obesity. Conclusions In a general Japanese population, obesity is progressively associated with pack-years and number of cigarettes per day, but not with the duration of smoking. When investigating the association between obesity and cigarette smoking, the daily smoking burden and the duration of smoking require to be independently considered. PMID:27007232

  3. Dosage response mortality of Japanese beetle, masked chafer, and June beetle (Coleoptera: Scarabaeidae) adults when exposed to experimental and commercially available granules containing Metarhizium brunneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adult beetles of three different white grub species, Japanese beetle, Popillia japonica, June beetle, Phyllophaga spp., and masked chafer, Cyclocephala spp. were exposed to experimental and commercially available granules containing Metarhizium brunneum (Petch) strain F52, to determine susceptibilit...

  4. Effects of Biopesticides on Foliar Diseases and Japanese Beetle (Popillia japonica) Adults in Roses (Rosa spp.), Oakleaf Hydrangea (Hydrangea quercifolia), and Crapemyrtle (Lagerstroemia indica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated efficacy of biopesticides for reducing foliar diseases and feeding damage from Japanese beetle adults on hybrid T rose (Rosa spp.), oakleaf hydrangea (Hydrangea quercifolia), and crapemyrtle (Lagerstroemia indica). The materials tested included household soaps with Triclosan act...

  5. How Japanese adults perceive memory change with age: middle-aged adults with memory performance as high as young adults evaluate their memory abilities as low as older adults.

    PubMed

    Kinjo, Hikari; Shimizu, Hiroyuki

    2014-01-01

    The characteristics of self-referent beliefs about memory change with age. The relationship between beliefs and memory performance of three age groups of Japanese adults was investigated. The beliefs measured by the Personal Beliefs about Memory Instrument (Lineweaver & Hertzog, 1998) differed among the age groups and between sexes. In most scales, the ratings by middle-aged adults were as low as those by older adults, which were lower than those by young adults. Women perceived their memory abilities as lower than men's, with no interaction between age and sex, suggesting the difference remains across the lifespan. For middle-aged adults, the better they performed in cued-recall, free recall, and recognition, the lower they evaluated their memory self-efficacy, while few relationships were found for other groups. Our results suggest that cognitive beliefs change with age and that investigating the beliefs of the middle-aged adults is indispensable to elucidate the transition of beliefs. PMID:24669510

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

    PubMed Central

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

    2016-01-01

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

  7. Prevalence and Correlates of Insufficient Sleep Syndrome in Japanese Young Adults: A Web-Based Cross-Sectional Study

    PubMed Central

    Morita, Yuko; Sasai-Sakuma, Taeko; Asaoka, Shoichi; Inoue, Yuichi

    2015-01-01

    Study Objectives: This study investigated the prevalence and risk factors of insufficient sleep syndrome (ISS), and factors associated with daytime dysfunction in the disorder in Japanese young adults. Methods: In this cross-sectional study, a web-based questionnaire survey was used to assess demographic variables, sleep habits and quality, depressive symptoms, and health-related quality of life (HRQOL) in 2,276 participants aged 20–25. Results: Eleven percent of participants were classified as having ISS. Multiple logistic regression analysis revealed that the presence of ISS was significantly associated with social status (student or full-time employee). The participants with ISS had significantly higher depression scores and lower mental component summary scores than healthy sleepers. In the participants with ISS, a delayed sleep-wake schedule was extracted as a factor associated with worse mental component summary. Conclusions: Results indicate a relatively high proportion of Japanese young adults suffer from ISS, and that the condition is associated with a social status of student or full-time employee. Moreover, a delayed sleep-wake schedule may lead to further deterioration of mental HRQOL in ISS-affected persons. Citation: Morita Y, Sasai-Sakuma T, Asaoka S, Inoue Y. Prevalence and correlates of insufficient sleep syndrome in Japanese young adults: a web-based cross-sectional study. J Clin Sleep Med 2015;11(10):1163–1169. PMID:26094926

  8. Dish influences implicit gender-based food stereotypes among young Japanese adults.

    PubMed

    Kimura, Atsushi; Wada, Yuji; Asakawa, Akio; Masuda, Tomohiro; Goto, Sho-ichi; Dan, Ippeita; Oka, Takashi

    2012-06-01

    The present study explored whether the gender impression of a dish affects the gender stereotypes of foods. We assessed gender stereotypes of food among young Japanese adults using a semantic priming task. As prime stimuli, we took pictures of food in combination with a dish. We used feminine- and masculine-evaluated foods and dishes in order to create four different combinations of food and dishes. In the semantic priming task, we primed the participants (n=58) with the pictures of food-dish combinations and immediately after the priming, we presented them with forenames as target stimuli and let them decide whether the forename given was feminine or masculine. By so doing, we estimated the semantic association between the food-dish combinations with gender. The results demonstrate that gender impressions of dishes affect gender stereotypes toward foods. The feminine-evaluated dish exhibited a facilitation of the femininity and an inhibition of the masculinity of foods. Similarly, the masculine-evaluated dish exhibited a facilitation of the masculinity and an inhibition of the femininity of foods. These results suggest that gender-based stereotypical attitudes toward food pictures are determined by the combination of gender impressions for both the food itself and its dish. PMID:22349777

  9. A Case Series of Three US Adults with Japanese Encephalitis, 2010-2012

    PubMed Central

    Hills, Susan L.; Stoltey, Juliet; Martínez, Diana; Kim, Paul Y.; Sheriff, Heather; Zangeneh, Ana; Eilerman, Sally R.; Fischer, Marc

    2015-01-01

    Background Japanese encephalitis (JE) virus is the leading vaccine-preventable cause of encephalitis in Asia. Although the risk for JE for most travelers to Asia is low, it varies based on the destination, season, trip duration, and activities. Methods We present case reports for three US adults who were infected with JE virus while traveling or residing in Asia. Results Among the three JE cases, one case had a 10-day trip to mainland China and participated in outdoor activities in a rural area, a second case had been resident in Taiwan for 4 months, and a third, fatal case was an expatriate living in South Korea. Conclusions JE should be considered in the differential diagnosis for any patient with an acute neurologic infection who recently has been in a JE-endemic country. Health-care providers should assess the itineraries of travelers to JE-endemic countries, provide guidance on personal protective measures to prevent vector-borne diseases, and consider recommending JE vaccine for travelers at increased risk for JE virus infection. PMID:24861145

  10. Tri-Axial Accelerometer-Determined Daily Physical Activity and Sedentary Behavior of Suburban Community-Dwelling Older Japanese Adults

    PubMed Central

    Chen, Tao; Narazaki, Kenji; Honda, Takanori; Chen, Sanmei; Haeuchi, Yuki; Nofuji, Yu Y; Matsuo, Eri; Kumagai, Shuzo

    2015-01-01

    Knowledge regarding accelerometer-derived physical activity (PA) and sedentary behavior (SED) levels is scarce for Japanese older adults. The aims of this study were therefore to 1) describe levels of PA and SED in Japanese community-dwelling older adults, using tri-axial accelerometer; 2) examine the variation of PA and SED with respect to sex, age, and body mass index (BMI). Participants of this study were from the baseline survey of the Sasaguri Genkimon Study, who were 65 years or older and not certified as those requiring long-term care. PA was assessed objectively for seven consecutive days using tri-axial accelerometer. A total of 1,739 participants (median age: 72 years, men: 38.0%) with valid PA data were included. Overall, participants in the present study spent 54.5% of their waking time being sedentary and 45.5% being active, of which 5.4% was moderate-to-vigorous physical activity (MVPA). Women accumulated more minutes of light physical activity (LPA) and MVPA compared with men. In contrast, men spent more time being sedentary. Mean steps per day did not differ between sexes. Furthermore, participants with higher BMI (BMI ≥25) had lower PA levels, and longer SED compared with those with lower BMI (BMI <). PA levels were lower and SED was longer with age. The present study is the first to demonstrate that the levels of PA and SED differed by sex, age, and BMI in Japanese community-dwelling older adults. In particular, women were more active compared with men, providing unique insight into the current level of PA in older adults. Data presented in the study will enable further investigation of additional determinants of PA and SED in order to develop effective population-based intervention strategies to promote PA and reduce prolonged SED in the Japanese population and possibly other rapidly aging societies. Key points Accelerometer, that is capable to assess PA more precisely in large scale epidemiological studies, provides opportunity for improving

  11. Phonetic training with acoustic cue manipulations: A comparison of methods for teaching English /r/-/l/ to Japanese adults

    NASA Astrophysics Data System (ADS)

    Iverson, Paul; Hazan, Valerie; Bannister, Kerry

    2005-11-01

    Recent work [Iverson et al. (2003) Cognition, 87, B47-57] has suggested that Japanese adults have difficulty learning English /r/ and /l/ because they are overly sensitive to acoustic cues that are not reliable for /r/-/l/ categorization (e.g., F2 frequency). This study investigated whether cue weightings are altered by auditory training, and compared the effectiveness of different training techniques. Separate groups of subjects received High Variability Phonetic Training (natural words from multiple talkers), and 3 techniques in which the natural recordings were altered via signal processing (All Enhancement, with F3 contrast maximized and closure duration lengthened; Perceptual Fading, with F3 enhancement reduced during training; and Secondary Cue Variability, with variation in F2 and durations increased during training). The results demonstrated that all of the training techniques improved /r/-/l/ identification by Japanese listeners, but there were no differences between the techniques. Training also altered the use of secondary acoustic cues; listeners became biased to identify stimuli as English /l/ when the cues made them similar to the Japanese /r/ category, and reduced their use of secondary acoustic cues for stimuli that were dissimilar to Japanese /r/. The results suggest that both category assimilation and perceptual interference affect English /r/ and /l/ acquisition.

  12. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation.

    PubMed

    Shirakashi, Ryo; Mischke, Miriam; Fischer, Peter; Memmel, Simon; Krohne, Georg; Fuhr, Günter R; Zimmermann, Heiko; Sukhorukov, Vladimir L

    2012-11-01

    The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture. PMID:23063978

  13. Changes in the dielectric properties of medaka fish embryos during development, studied by electrorotation

    SciTech Connect

    Shirakashi, Ryo; Mischke, Miriam; Fischer, Peter; Memmel, Simon; Krohne, Georg; Fuhr, Guenter R.; Zimmermann, Heiko; Sukhorukov, Vladimir L.

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Electrorotation offers a non-invasive tool for dielectric analysis of fish embryos. Black-Right-Pointing-Pointer The three-shell dielectric model matches the rotation spectra of medaka eggs. Black-Right-Pointing-Pointer The capacitance value suggests a double-membrane structure of yolk envelope. -- Abstract: The Japanese medaka fish, Oryzias latipes, has become a powerful vertebrate model organism in developmental biology and genetics. The present study explores the dielectric properties of medaka embryos during pre-hatching development by means of the electrorotation (ROT) technique. Due to their layered structure, medaka eggs exhibited up to three ROT peaks in the kHz-MHz frequency range. During development from blastula to early somite stage, ROT spectra varied only slightly. But as the embryo progressed to the late-somite stage, the ROT peaks underwent significant changes in frequency and amplitude. Using morphological data obtained by light and electron microscopy, we analyzed the ROT spectra with a three-shell dielectric model that accounted for the major embryonic compartments. The analysis yielded a very high value for the ionic conductivity of the egg shell (chorion), which was confirmed by independent osmotic experiments. A relatively low capacitance of the yolk envelope was consistent with its double-membrane structure revealed by transmission electron microscopy. Yolk-free dead eggs exhibited only one co-field ROT peak, shifted markedly to lower frequencies with respect to the corresponding peak of live embryos. The dielectric data may be useful for monitoring the development and changes in fish embryos' viability/conditions in basic research and industrial aquaculture.

  14. Correlates of Regular Participation in Sports Groups among Japanese Older Adults: JAGES Cross–Sectional Study

    PubMed Central

    Yamakita, Mitsuya; Kanamori, Satoru; Kondo, Naoki; Kondo, Katsunori

    2015-01-01

    Background Participation in a sports group is key for the prevention of incident functional disability. Little is known about the correlates of older adults’ participation in sports groups, although this could assist with the development of effective health strategies. The purpose of this study was to identify the demographic and biological, psychosocial, behavioral, social and cultural, and environmental correlates of sports group participation among Japanese older adults. Methods Data were obtained from the Japan Gerontological Evaluation study, which was a population–based cohort of people aged ≥65 years without disability enrolled from 31 municipalities across Japan (n = 78,002). Poisson regression analysis was used to determine the associations between the factors and participation in sports groups. Results Non-regular participation in sports groups was associated with lower educational level, being employed, and working the longest in the agricultural/forestry/fishery industry among the demographic and biological factors and poor self-rated health and depression among the psychosocial factors. Of the behavioral factors, current smoking was negatively associated and current drinking was positively associated with regular participation in sports groups. Among the social and cultural factors, having emotional social support and participating in hobby clubs, senior citizen clubs, or volunteer groups were associated with a high prevalence of participation in sports groups. Perceptions of the presence of parks or sidewalks, good access to shops, and good accessibility to facilities were positively associated with participation in sports groups among the environmental factors. Conclusions Our study suggests that the promotion of activities that could increase older adults’ participation in sports groups should consider a broad range of demographic and biological, psychosocial, behavioral, social and cultural, and environmental factors. Although future

  15. A Qualitative Study of Confusing Experiences among Japanese Adult Patients with Type 1 Diabetes

    PubMed Central

    Nishio, Ikuko; Chujo, Masami; Kataoka, Hideyuki

    2016-01-01

    Background In this study, we investigated the powerlessness of patients with type 1 diabetes (T1D), and described the structure of powerlessness that these individuals experienced. In order for patients to recover from this state, we recommend that they take steps to regain their power. Methods Fifteen Japanese adults with T1D participated in this study. Data were collected from all subjects between July 2013 and March 2014 via in-depth semi-structured interviews. Qualitative data analysis was conducted according to a grounded theory approach. Finally, the core category was identified, which allowed us to build a new powerlessness structure for T1D. Results The results suggested a core category, ‘Wandering a tangled path,’ comprising four categories, eight subcategories, and twenty-six concepts. These four categories were as follows: ‘being burdened by T1D,’ ‘suffering from insulin-related troubles,’ ‘being unable to cope with difficulties in self-management,’ and ‘facing social prejudice.’ In the state of powerlessness, negative emotional experiences snowballed, with patients feeling more and more depressed until they ultimately reached ‘rock bottom.’ Conclusion We found that as negative emotional experiences related to powerlessness increased, negative feelings intensified until the patients reached rock bottom. Powerlessness is like ‘wandering a tangled path,’ a state in which T1D patients struggle to cope with reality on their own when faced with both internal and external events. ‘Wandering a tangled path’ is at the core of powerlessness. A primary characteristic of the structure of powerlessness is suffering from confusing experiences. To help patients cope with T1D without being crushed by powerlessness, nurses must pay attention to signs of powerlessness. Powerlessness is not just an emotional state, but a combination of feelings, perceptions, and thoughts; therefore, it is important to comprehensively understand patients

  16. Effects of Pyrroloquinoline Quinone Disodium Salt Intake on the Serum Cholesterol Levels of Healthy Japanese Adults.

    PubMed

    Nakano, Masahiko; Kawasaki, Yuuki; Suzuki, Naoko; Takara, Tsuyoshi

    2015-01-01

    Pyrroloquinoline quinone (PQQ) is a water-soluble quinone compound that has a strong anti-oxidant capacity. A previous study in rats fed a PQQ-depleted diet showed that elevated levels of serum triglyceride (TG) decreased after PQQ supplementation. However, there is only one study reporting the effects of PQQ on serum lipid levels, such as those of TG and cholesterol, in humans. In this study, the effects of PQQ disodium salt (BioPQQ™) on serum TG and cholesterol levels in humans after 6 and 12 wk of treatment at an oral dosage of 20 mg/d were examined. This trial was conducted according to a randomized, placebo-controlled, double-blinded protocol. A total of 29 healthy Japanese adults, ranging from 40 to 57 y old, with normal to moderately high TG levels (110-300 mg/dL) as measured by a recent blood examination, were included in this study. In eleven volunteers out of 29, serum low-density lipoprotein cholesterol (LDL-chol) levels at baseline were high (≥140 mg/dL). After 12 wk, the mean serum TG levels had not changed; however, a marginally significant decrease in the mean LDL-chol (from 136.1 to 127.0 mg/dL) was observed in the PQQ group. In the stratification analysis of the high LDL-chol subgroup (baseline LDL-chol level ≥140 mg/dL), the mean LDL-chol levels decreased significantly from the baseline values in the PQQ group compared to the placebo group. Our study findings suggest that PQQ suppressed the LDL-chol level, which is an important finding, because a high level of this lipid is a risk factor for various lifestyle-related diseases. PMID:26226960

  17. Less indoor cleaning is associated with poor health and unhappiness in adults: Japanese General Social Survey, 2010.

    PubMed

    Shiue, Ivy

    2015-12-01

    Indoor environment is important to human health and well-being. The aim of the present study was to investigate the relationships among indoor cleaning, rubbish disposal and human health and well-being in a national and population-based setting. Data was retrieved from the Japanese General Social Survey, 2010. Information on demographics, lifestyle factors, frequency of indoor cleaning and rubbish disposal and self-reported health and well-being in Japanese adults was obtained by household interview. Analysis included chi-square test, logistic and multi-nominal regression modelling. Of 5003 Japanese adults (aged 20-89) included in the study cohort, 11.4 % (n = 566) never cleaned their living place, 39.1 % had occasional cleaning and 49.6 % had frequent cleaning. Moreover, 17.5 % (n = 869) never disposed rubbish, 24.9 % had occasional rubbish disposal and 57.6 % had frequent rubbish disposal. 15.0 % of Japanese adults claimed poor self-rated health, and 5.9 % reported unhappiness. Compared to people who frequently cleaned the living place, others tended to report poor self-rated health condition (relative risk ratios (RRR) 1.52, 95 % confidence intervals (CI) 1.24-1.85, P < 0.001) and unhappiness (RRR 1.47, 95 % CI 1.10-1.95, P < 0.001). The combined effects of never cleaning and never rubbish disposal significantly impacted on poor self-rated health (RRR 2.61, 95 % CI 1.40-4.88, P = 0.003) and unhappiness (RRR 2.72, 95 % CI 1.72-4.30, P < 0.001). Only half of the Japanese population frequently cleaned their living place and disposed rubbish. Less or never cleaning and rubbish disposal were associated with poor self-rated health, subjective happiness and potentially other health conditions. Public education on maintaining clean indoor environments to optimise psychological well-being in addition to the known physical health would be suggested. PMID:26503003

  18. Far from Oblivion: the Nanking Massacre in Japanese historical writing for children and young adults.

    PubMed

    Penney, Matthew

    2008-01-01

    The Nanking Massacre of 1937 frequently has been described as a forgotten genocidal act or "Holocaust." Concentrating on atrocity as reflected in Japanese popular historical writing for children and adolescents since the 1960s, this essay argues that such war crimes are far from ignored. Representations of the Nanking Massacre in particular, and of Japanese World War II atrocities in general, have been widely mobilized in Japan to inculcate an anti-war philosophy. PMID:20681109

  19. Estimation of Trans Fatty Acid Intake in Japanese Adults Using 16-Day Diet Records Based on a Food Composition Database Developed for the Japanese Population

    PubMed Central

    Yamada, Mai; Sasaki, Satoshi; Murakami, Kentaro; Takahashi, Yoshiko; Okubo, Hitomi; Hirota, Naoko; Notsu, Akiko; Todoriki, Hidemi; Miura, Ayako; Fukui, Mitsuru; Date, Chigusa

    2010-01-01

    Background The Standard Tables of Food Composition in Japan do not include information on trans fatty acids. Previous studies estimating trans fatty acid intake among Japanese have limitations regarding the databases utilized and diet assessment methodologies. We developed a comprehensive database of trans fatty acid food composition, and used this database to estimate intake among a Japanese population. Methods The database was developed using analytic values from the literature and nutrient analysis software encompassing foods in the US, as well as values estimated from recipes or nutrient compositions. We collected 16-day diet records from 225 adults aged 30 to 69 years living in 4 areas of Japan. Trans fatty acid intake was estimated based on the database and the 16-day diet records. Results Mean total fat and trans fatty acid intake was 56.9 g/day (27.7% total energy) and 1.7 g/day (0.8% total energy), respectively, for women and 66.8 g/day (25.5% total energy) and 1.7 g/day (0.7% total energy) for men. Trans fatty acid intake accounted for greater than 1% of total energy intake, which is the maximum recommended according to the World Health Organization, in 24.4% of women and 5.7% of men, and was particularly high among women living in urban areas and those aged 30–49 years. The largest contributors to trans fatty acid intake were confectionaries in women and fats and oils in men. Conclusions Although mean trans fatty acid intake was below the maximum recommended intake of the World Health Organization, intake among subgroups was of concern. Further public health efforts to reduce trans fatty acid intake should be encouraged. PMID:20037259

  20. EFFECTS OF CADMIUM ON THE REPRODUCTIVE AXIS OF JAPANESE MEDAKA

    EPA Science Inventory

    Cadmium (Cd) is a ubquitous element and a significant inorganic pollutant that has previously been found to bioaccumulate in reproductive organs of fish and disrupt important endocrine processes, especially those involved in synthesis, release and metabolism of hormones. Clearly,...

  1. The experience of Japanese adolescents and young adults after losing siblings to childhood cancer: three types of narratives.

    PubMed

    Kamibeppu, Kiyoko; Sato, Iori; Hoshi, Yasutaka

    2015-01-01

    The aim of this study was to describe Japanese adolescents' and young adults' experiences after losing siblings to childhood cancer. A conceptual framework of the transition and analysis based on narrative method were adopted from qualitative data from 6 Japanese adolescents and young adults who had lost their siblings to childhood cancer. It was revealed that the participants' psychological experience after the sibling's death was directed by their perceptions of their mothers' responses to bereavement. We also found that the psychological distance between participants and their mothers could be an important factor in enabling transition into mourning and in orienting the lost sibling in their mind. The stories obtained from these 6 participants were categorized into the following 3 types of narratives: "Mother in another world and the sibling who became a god," "Return of the loving mother and the sibling as savior," and "The poor mother and the sibling who needs my help to carry on her legacy." This typology will serve as a framework for grief care and future research. PMID:25413258

  2. Origin of Boundary Populations in Medaka (Oryzias latipes Species Complex).

    PubMed

    Takehana, Yusuke; Sakai, Masato; Narita, Takanori; Sato, Tadashi; Naruse, Kiyoshi; Sakaizumi, Mitsuru

    2016-04-01

    The Japanese wild population of the medaka fish (Oryzias latipes species complex) comprises two genetically distinct groups, the Northern and the Southern Populations, with boundary populations having a unique genotype. It is thought that the boundary populations have been formed through introgressive hybridization between the two groups, because they are fixed with the Northern alleles at two allozymic loci, with the Southern alleles at two other loci, and have a unique allele at one locus. In this study, we examined the genetic population structure of the boundary populations using genome-wide single nucleotide polymorphism (SNP) data. Most SNPs of the Toyooka population, a typical boundary population, were shared with the Northern Population, some were shared with the Southern Population, and the remaining SNPs were unique to this population, suggesting that the boundary populations originated and diverged from the Northern Population. Further analyses of different populations using SNPs at eight genomic loci indicated that the boundary populations at different locations share similar genomic constitutions, and can be genetically distinguished from typical Northern Populations by unique SNPs. In addition, the boundary populations in the Maruyama River Basin had Northern mitochondrial DNA (mtDNA), while others, from the Fukuda and Kishida River Basins and from the Kumihama Bay area, had Southern mtDNA. These findings suggested that the boundary populations originated from the Northern Population, and then their genomes diverged as a result of geographical isolation, followed by mtDNA introgression from the Southern Population that occurred independently in some populations. PMID:27032677

  3. NON-INVASIVE NEUROTOXICITY ASSAY USING LARVAL MEDAKA

    EPA Science Inventory

    We present a method for non-invasive electrophysiological analysis of rapid escape responses in intact, freely behaving larval medaka (Oryzias latipes) before and after short-term exposure to environmental toxicants. ecordings are obtained as a larval medaka swims in a small cham...

  4. A new in vitro ovulation model for medaka based on whole ovary culture.

    PubMed

    Ogiwara, Katsueki; Ikeda, Takashi; Takahashi, Takayuki

    2010-09-01

    We sought to establish a new in vitro ovulation model using the whole ovaries of the medaka. Ovaries of the fish, which had been acclimated to the usual reproductive conditions (26 degrees C, 14 h light/10 h dark) and which had then been kept at least one day at 30 degrees C, were isolated 2 h before the expected in vivo ovulation time. When the ovaries were cultured in 90% medium 199 solution at 30 degrees C or 36 degrees C, oocytes were liberated with a gradual increase in the ovulation rate at 2 to 5 h of ovulation time. The maximum ovulation rate was approximately 45%. Ovulated oocytes were fertilized and subsequently developed into adults. In vitro ovulation of medaka ovaries was inhibited by the addition of metalloproteinase inhibitors to the culture. In this in vitro ovulation model, the holes formed on the follicle layer upon follicle rupture at ovulation were sealed, strongly suggesting the importance of the germinal epithelium in the process. The present study indicates that our new in vitro ovulation model is useful for investigating the role of germinal epithelial cells in the ovulate process of the medaka fish. PMID:20822405

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

    USGS Publications Warehouse

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

    2000-01-01

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

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

    PubMed

    Ijiri, Kenichi

    2003-01-01

    Fish are the most likely candidates to be the first vertebrate to live their life cycle aboard the International Space Station (ISS). In the space-shuttle experiment using medaka, the fry born in space had the same number of germ cells as the ground control fish, and these germ cells later developed to produce the offspring on the ground. Fry hatched in space did not exhibit any looping behavior regardless of their strain, visual acuity, etc. The aquatic habitat (AQH) is a space habitat designed for long-term breeding of medaka, zebrafish and Xenopus, and recent advancements in this hardware also support fish life-cycle experiments. From the crosses between two strains, fish having good eyesight and less sensitivity to gravity were obtained, and their tolerance to microgravity was tested by parabolic flight using an airplane. The fish exhibited less looping and no differences in degree of looping between light and dark conditions. These are possible candidates for the first adult medaka (parent fish) to start a life cycle aboard ISS. Embryos were treated with a three-dimensional clinostat. Such simulated microgravity caused no differences in tissue architecture or in gene expression within the retina, nor in formation of cartilage (head skeleton). Otolith formation in embryos and fry was investigated for wild-type and mutant (ha) medaka. The ha embryos could not form utricular otoliths. They formed saccular otoliths but with a delay. Fry of the mutant fish lacking the utricular otoliths are highly light-dependent at the time of hatching, showing a perfect dorsal-light response (DLR). As they grow, they eventually shift from being light dependent to gravity dependent. Continuous treatment of the fry with altered light direction suppressed this shift to gravity dependence. Being less dependent on gravity, these fish can serve as model fish in studying the differences expected for the fish that have experienced a life cycle in microgravity. PMID:14631634

  7. The early phase of /see symbol/ production development in adult Japanese learners of English.

    PubMed

    Saito, Kazuya; Munro, Murray J

    2014-12-01

    Although previous research indicates that Japanese speakers' second language (L2) perception and production of English /see symbol/ may improve with increased L2 experience, relatively little is known about the fine phonetic details of their /see symbol/ productions, especially during the early phase of L2 speech learning. This cross-sectional study examined acoustic properties of word-initial /see symbol/ from 60 Japanese learners with a length of residence of between one month and one year in Canada. Their performance was compared to that of 15 native speakers of English and 15 low-proficiency Japanese learners of English. Formant frequencies (F2 and F3) and F1 transition durations were evaluated under three task conditions--word reading, sentence reading, and timed picture description. Learners with as little as two to three months of residence demonstrated target-like F2 frequencies. In addition, increased LOR was predictive of more target-like transition durations. Although the learners showed some improvement in F3 as a function of LOR, they did so mainly at a controlled level of speech production. The findings suggest that during the early phase of L2 segmental development, production accuracy is task-dependent and is influenced by the availability of L1 phonetic cues for redeployment in L2. PMID:25536843

  8. Adult Education for Peace: Japanese Experiences. Peace Education Miniprints No. 74.

    ERIC Educational Resources Information Center

    Fujita, Hideo

    To this point peace education has been carried out and discussed more in elementary and high schools than in adult education. This paper stresses the need for adult education for peace and discusses the organization, content, and methods of such education, with special attention to experiences in Japan. Methods of adult education for peace in…

  9. Ontogeny and Sexual Differences in Swimming Proximity to Conspecifics in Response to Visual Cues in Medaka Fish.

    PubMed

    Isoe, Yasuko; Konagaya, Yumi; Yokoi, Saori; Kubo, Takeo; Takeuchi, Hideaki

    2016-06-01

    Adult medaka fish (Oryzias latipes) exhibit complex social behaviors that depend mainly on visual cues from conspecifics. The ontogeny of visually-mediated social behaviors from larval/juvenile to adult medaka fish, however, is unknown. In the present study, we established a simple behavioral paradigm to evaluate the swimming proximity to conspecifics based on visual cues in an inter-individual interaction of two medaka fish throughout life. When two fish were placed separately in a cylindrical tank with a concentric transparent wall, the two fish maintained close proximity to each other. A normal fish inside the tank maintained proximity to an optic nerve-cut fish outside of the tank, while the converse was not true. This behavioral paradigm enabled us to quantify visually-induced motivation of a single fish inside the tank. The proximity was detected from larval/juvenile to adult fish. Larval fish, however, maintained close proximity not only to conspecifics, but also to heterospecifics. As the growth stage increased, the degree of proximity to heterospecifics decreased, suggesting that shoaling preferences toward conspecifics and/or visual ability to recognize conspecifics is refined and established according to the growth stage. Furthermore, the proximity of adult female fish was affected by their reproductive status and social familiarity. Only before spawning, adult females maintained closer proximity to familiar males rather than to unfamiliar males, suggesting that proximity was affected by familiarity in a female-specific manner. This simple behavioral paradigm will contribute to our understanding of the neural basis of the development of visually-mediated social behavior using medaka fish. PMID:27268978

  10. Adapting the medaka embryo assay to a high-throughput approach for developmental toxicity testing.

    PubMed

    Oxendine, Sharon L; Cowden, John; Hinton, David E; Padilla, Stephanie

    2006-09-01

    Chemical exposure during embryonic development may cause persistent effects, yet developmental toxicity data exist for very few chemicals. Current testing procedures are time consuming and costly, underlining the need for rapid and low cost screening strategies. While in vitro methods are useful for screening, these methods do not replicate all the intricacies of embryonic development and should ideally be complemented by an in vivo screening strategy. In this study, we modify a medaka fish embryo assay to meet the requirements of high-throughput, developmental toxicant testing in vivo. The Japanese medaka (Oryzias latipes) offers several advantages over traditional mammalian model systems, including economic husbandry, high fecundity, and rapid ex utero development. In most studies where fish eggs are exposed to a chemical, the exposure takes place in a common vessel, with many embryos being exposed to the same solution. This type of design is not amenable to high-throughput methodology, does not allow the investigator to follow the same embryo throughout gestation, and may confound statistical analysis of the results. Therefore, we developed a 96-well microtiter plate method to facilitate exposure of individual medaka embryos in single wells and compared this approach to the common vessel method using the industrial solvent dimethyl sulfoxide (DMSO) as the test compound. At lower DMSO concentrations (0% or 1%), the 96-well microtiter plate assay replicated results obtained using the common vessel exposure method. There was, however, increased lethality and decreased hatching rate in the bottle-reared embryos treated with the higher DMSO concentrations (5% or 10%). Because the embryos reared in the 96-well microtiter plates never showed increased adverse effects (as compared to the bottle-reared embryos) at any DMSO concentration, we conclude that the 96-well microtiter plate assay provides a rapid and efficient alternative for developmental toxicity screens that

  11. a Cross-Sectional Study on Insomnia among Japanese Adult Women in Relation to Night-Time Road Traffic Noise

    NASA Astrophysics Data System (ADS)

    Kageyama, T.; Kabuto, M.; Nitta, N.; Kurokawa, Y.; Taira, K.; Suzuki, S.; Takemoto, T.

    1997-08-01

    In an effort to determine the contribution of night-time road traffic noise to insomnia in the general population, 3600 adult Japanese women living in urban residential areas were surveyed. Living near a road with a heavy traffic volume is one of the risk factors for insomnia. The risk for insomnia in the zones 0-20 m from the main roads increased linearly with the night-time traffic volume. This suggests that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas.

  12. Mycobacterium ulcerans causes minimal pathogenesis and colonization in Medaka (Oryzias latipes): An experimental fish model of disease transmission

    PubMed Central

    Mosi, Lydia; Mutoji, Nadine K.; Basile, Fritz A; Donnell, Robert; Jackson, Kathrine L.; Spangenberg, Thomas; Kishi, Yoshito; Ennis, Don G.; Small, Pamela L.C.

    2012-01-01

    Mycobacterium ulcerans causes Buruli ulcer in humans, a progressive ulcerative epidermal lesion due to the mycolactone toxin produced by the bacterium. Molecular analysis of M. ulcerans reveals it is closely related to M. marinum, a pathogen of both fish and man. Molecular evidence from diagnostic PCR assays for the insertion sequence IS2404 suggests an association of M. ulcerans with fish. However, fish infections by M. ulcerans have not been well documented and IS2404 has been found in other mycobacteria. We have thus, employed two experimental approaches to test for M. ulcerans in fish. We show here for the first time that M. ulcerans with or without the toxin does not mount acute or chronic infections in Japanese Medaka “Oryzias latipes” even at high doses. Moreover, M. ulcerans-infected medaka do not exhibit any visible signs of infection nor disease and the bacteria do not appear to replicate over time. In contrast, similar high doses of the wild-type M. marinum or a mycolactone producing M. marinum “DL” strain are able to mount an acute disease with mortality in medaka. Although these results would suggest that M. ulcerans does not mount infections in fish we have evidence that CLC macrophages from goldfish are susceptible to mycolactones. PMID:22465732

  13. Double left renal veins and multiple right renal veins found in Japanese adults.

    PubMed

    Yahiro, J; Miyoshi, S

    1993-12-01

    A case of circumaortic renal venous collar, the first such collar to be observed in a Japanese female cadaver, is presented, and its anatomical organization is compared with that in another case in which four right renal veins accompanied four right and three left renal arteries in a Japanese male cadaver. Double left renal veins are formed by persistence of a more central retroaortic venous anastomosis, in contrast to multiple right renal veins, which are formed by persistence of some embryonic renal veins arranged in ladder-like patterns. In our case, the dorsal limb of the renal collar communicated with the azygos system veins and lumbar veins. The azygos system veins were considered to have atrophied as a result of some persisting retroaortic venous anastomoses located in the thorax. Therefore, we believe that the renal collar was related to the atrophy of the azygos system veins. To determine whether there are racial differences in incidence of renal collar, further studies in Asians are required. PMID:8202308

  14. Serum 25-Hydroxyvitamin D Concentrations and Season-Specific Correlates in Japanese Adults

    PubMed Central

    Nanri, Akiko; Foo, Leng Huat; Nakamura, Kazutoshi; Hori, Ai; Poudel-Tandukar, Kalpana; Matsushita, Yumi; Mizoue, Tetsuya

    2011-01-01

    Background Several lines of evidence indicate an important role for vitamin D in the prevention of a range of diseases. Blood vitamin D levels show clear seasonal variation; however, data on the determinants of vitamin D status for each season are limited. We investigated the association between lifestyle and serum vitamin D concentration by season in Japanese workers. Methods Subjects were 312 men and 217 women aged 21 to 67 years who worked in municipal offices in Northern Kyushu, Japan and participated in a periodic checkup in July or November. Multiple linear regression analysis was used to examine the association between serum 25-hydroxivitamin D concentrations and lifestyle factors for each season. Results Mean serum 25-hydroxyvitamin D concentration was 27.4 ng/ml (68.4 nmol/L) and 21.4 ng/ml (53.4 nmol/L) for workers surveyed in July and November, respectively (P < 0.001); the prevalence of vitamin D deficiency (<20 ng/ml) was 9.3% and 46.7%, respectively (P < 0.001). In November, dietary vitamin D intake (in both sexes) and nonsmoking and physical activity (in men) were significantly associated with higher concentrations of serum 25-hydroxyvitamin D. In summer, fish/shellfish intake was associated with higher serum 25-hydroxyvitamin D concentrations in women. Conclusions Vitamin D deficiency is common in Japanese workers during seasons with limited sunlight. The lifestyle correlates of favorable vitamin D status in November were physical activity, dietary vitamin D intake, and nonsmoking. PMID:21747209

  15. Numerical Analysis of Organ Doses Delivered During Computed Tomography Examinations Using Japanese Adult Phantoms with the WAZA-ARI Dosimetry System.

    PubMed

    Takahashi, Fumiaki; Sato, Kaoru; Endo, Akira; Ono, Koji; Ban, Nobuhiko; Hasegawa, Takayuki; Katsunuma, Yasushi; Yoshitake, Takayasu; Kai, Michiaki

    2015-08-01

    A dosimetry system for computed tomography (CT) examinations, named WAZA-ARI, is being developed to accurately assess radiation doses to patients in Japan. For dose calculations in WAZA-ARI, organ doses were numerically analyzed using average adult Japanese male (JM) and female (JF) phantoms with the Particle and Heavy Ion Transport code System (PHITS). Experimental studies clarified the photon energy distribution of emitted photons and dose profiles on the table for some multi-detector row CT (MDCT) devices. Numerical analyses using a source model in PHITS could specifically take into account emissions of x rays from the tube to the table with attenuation of photons through a beam-shaping filter for each MDCT device based on the experiment results. The source model was validated by measuring the CT dose index (CTDI). Numerical analyses with PHITS revealed a concordance of organ doses with body sizes of the JM and JF phantoms. The organ doses in the JM phantoms were compared with data obtained using previously developed systems. In addition, the dose calculations in WAZA-ARI were verified with previously reported results by realistic NUBAS phantoms and radiation dose measurement using a physical Japanese model (THRA1 phantom). The results imply that numerical analyses using the Japanese phantoms and specified source models can give reasonable estimates of dose for MDCT devices for typical Japanese adults. PMID:26107430

  16. Perceived Parental Rejection Mediates the Influence of Serotonin Transporter Gene (5-HTTLPR) Polymorphisms on Impulsivity in Japanese Adults

    PubMed Central

    Nishikawa, Saori; Nishitani, Shota; Fujisawa, Takashi X.; Noborimoto, Ippei; Kitahara, Takayuki; Takamura, Tsunehiko; Shinohara, Kazuyuki

    2012-01-01

    This study examined (1) the interrelationships among 5-HTTLPR genotype, perceived parental rejection, and impulsivity, and (2) meditational models in which perceived paternal/maternal rejection mediates the relationship between the 5-HTTLPR genotype and impulsive behaviour. Participants included 403 adults (152 males and 252 females, mean age = 24.20) who provided genetic data and a set of the questionnaires (BIS11; Barratt Impulsiveness Scale-11 and EMBU; Egna Minnen av Bätraffande Uppfostran). Using SEM (Structural Equation Modeling), we evaluated 3 models for both direct and indirect relationships between 5-HTTLPR (5HTT) and Impulsivity (IMP), via maternal/fraternal rejection (MAT/FAT). In model 1, the direct path from 5HTT and IMP was not significant across the mother’s and father’s analysis. Models 2 and 3 assessed the indirect influence of 5HTT on IMP through MOT/FAT. The paths of models 2 and 3 were all significant and showed a good fit between the hypothesized model and data. Furthermore, the effects of the 5-HTTLPR genotype on impulsiveness in this Japanese sample were particularly accounted for by perceived rejection from the mother or father. The effects from the parents appeared to be robust especially among males. These results may help elucidate the specific pathways of risk in relation to genetic and environment influences on impulsive phenotypes. PMID:23112823

  17. Correlation between a liking for fat-rich foods and body fatness in adult Japanese: a gender difference.

    PubMed

    Nakamura, K; Shimai, S; Kikuchi, S; Tanaka, M

    2001-02-01

    The aim of the present study was to test the hypothesis that Japanese adults who like fat-rich foods have more body fatness and higher serum lipid levels than those who do not. The subjects were 540 male and 492 female workers under 41 years of age. A self-administered questionnaire determined four levels of liking for fat-rich foods. Anthropometric measurements were employed yielding body mass index (BMI), waist to hip circumference ratio (WHR), and skinfold thickness. Anthropometric values were compared among the levels of liking for fat-rich foods using analysis of covariance. For males, a liking for fat-rich foods was associated with BMI, WHR, whole-body skinfold thickness, and abdominal skinfold thickness (p<0.0001). In particular, those who like fat-rich foods "quite a bit" or "very much" showed significantly higher values than those who answered "no" or "a little". Multiple regression analysis showed that a liking for fat-rich foods explains 7-9% of the variation in the anthropometric indices, even when other lifestyles were taken into account. For females, such findings were not evident. There is a gender difference in the association between a liking for fat-rich foods and body fatness. The difference may be due to a female-specific attitude toward high-calorie foods. PMID:11161340

  18. Time Spent Walking and Risk of Diabetes in Japanese Adults: The Japan Public Health Center-Based Prospective Diabetes Study

    PubMed Central

    Kabeya, Yusuke; Goto, Atsushi; Kato, Masayuki; Matsushita, Yumi; Takahashi, Yoshihiko; Isogawa, Akihiro; Inoue, Manami; Mizoue, Tetsuya; Tsugane, Shoichiro; Kadowaki, Takashi; Noda, Mitsuhiko

    2016-01-01

    Background The association between time spent walking and risk of diabetes was investigated in a Japanese population-based cohort. Methods Data from the Japan Public Health Center-based Prospective Diabetes cohort were analyzed. The surveys of diabetes were performed at baseline and at the 5-year follow-up. Time spent walking per day was assessed using a self-reported questionnaire (<30 minutes, 30 minutes to <1 hour, 1 to <2 hours, or ≥2 hours). A cross-sectional analysis was performed among 26 488 adults in the baseline survey. Logistic regression was used to examine the association between time spent walking and the presence of unrecognized diabetes. We then performed a longitudinal analysis that was restricted to 11 101 non-diabetic adults who participated in both the baseline and 5-year surveys. The association between time spent walking and the incidence of diabetes during the 5 years was examined. Results In the cross-sectional analysis, 1058 participants had unrecognized diabetes. Those with time spent walking of <30 minutes per day had increased odds of having diabetes in relation to those with time spent walking of ≥2 hours (adjusted odds ratio [OR] 1.23; 95% CI, 1.02–1.48). In the longitudinal analysis, 612 participants developed diabetes during the 5 years of follow-up. However, a significant association between time spent walking and the incidence of diabetes was not observed. Conclusions Increased risk of diabetes was implied in those with time spent walking of <30 minutes per day, although the longitudinal analysis failed to show a significant result. PMID:26725285

  19. Japanese; Japanese Songs.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This supplementary textbook for students of Japanese presents a collection of 43 songs--folk songs, nursery songs, lullabies, love songs, wedding songs, graduation songs, the national anthem, drinking songs, school songs, and Christmas carols. With the exception of the carols, the musical scores are presented with their Japanese lyrics. The…

  20. Whole Body Melanoma Transcriptome Response in Medaka

    PubMed Central

    Schartl, Manfred; Shen, Yingjia; Maurus, Katja; Walter, Ron; Tomlinson, Chad; Wilson, Richard K.; Postlethwait, John; Warren, Wesley C.

    2015-01-01

    The incidence of malignant melanoma continues to increase each year with poor prognosis for survival in many relapse cases. To reverse this trend, whole body response measures are needed to discover collaborative paths to primary and secondary malignancy. Several species of fish provide excellent melanoma models because fish and human melanocytes both appear in the epidermis, and fish and human pigment cell tumors share conserved gene expression signatures. For the first time, we have examined the whole body transcriptome response to invasive melanoma as a prelude to using transcriptome profiling to screen for drugs in a medaka (Oryzias latipes) model. We generated RNA-seq data from whole body RNA isolates for controls and melanoma fish. After testing for differential expression, 396 genes had significantly different expression (adjusted p-value <0.02) in the whole body transcriptome between melanoma and control fish; 379 of these genes were matched to human orthologs with 233 having annotated human gene symbols and 14 matched genes that contain putative deleterious variants in human melanoma at varying levels of recurrence. A detailed canonical pathway evaluation for significant enrichment showed the top scoring pathway to be antigen presentation but also included the expected melanocyte development and pigmentation signaling pathway. Results revealed a profound down-regulation of genes involved in the immune response, especially the innate immune system. We hypothesize that the developing melanoma actively suppresses the immune system responses of the body in reacting to the invasive malignancy, and that this mal-adaptive response contributes to disease progression, a result that suggests our whole-body transcriptomic approach merits further use. In these findings, we also observed novel genes not yet identified in human melanoma expression studies and uncovered known and new candidate drug targets for further testing in this malignant melanoma medaka model. PMID

  1. Whole Body Melanoma Transcriptome Response in Medaka.

    PubMed

    Schartl, Manfred; Shen, Yingjia; Maurus, Katja; Walter, Ron; Tomlinson, Chad; Wilson, Richard K; Postlethwait, John; Warren, Wesley C

    2015-01-01

    The incidence of malignant melanoma continues to increase each year with poor prognosis for survival in many relapse cases. To reverse this trend, whole body response measures are needed to discover collaborative paths to primary and secondary malignancy. Several species of fish provide excellent melanoma models because fish and human melanocytes both appear in the epidermis, and fish and human pigment cell tumors share conserved gene expression signatures. For the first time, we have examined the whole body transcriptome response to invasive melanoma as a prelude to using transcriptome profiling to screen for drugs in a medaka (Oryzias latipes) model. We generated RNA-seq data from whole body RNA isolates for controls and melanoma fish. After testing for differential expression, 396 genes had significantly different expression (adjusted p-value <0.02) in the whole body transcriptome between melanoma and control fish; 379 of these genes were matched to human orthologs with 233 having annotated human gene symbols and 14 matched genes that contain putative deleterious variants in human melanoma at varying levels of recurrence. A detailed canonical pathway evaluation for significant enrichment showed the top scoring pathway to be antigen presentation but also included the expected melanocyte development and pigmentation signaling pathway. Results revealed a profound down-regulation of genes involved in the immune response, especially the innate immune system. We hypothesize that the developing melanoma actively suppresses the immune system responses of the body in reacting to the invasive malignancy, and that this mal-adaptive response contributes to disease progression, a result that suggests our whole-body transcriptomic approach merits further use. In these findings, we also observed novel genes not yet identified in human melanoma expression studies and uncovered known and new candidate drug targets for further testing in this malignant melanoma medaka model. PMID

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

    PubMed

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

    2008-01-01

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

  3. Radiographic Determination of Hip Rotation Center and Femoral Offset in Japanese Adults: A Preliminary Investigation toward the Preoperative Implications in Total Hip Arthroplasty.

    PubMed

    Takamatsu, Taichiro; Shishido, Takaaki; Takahashi, Yasuhito; Masaoka, Toshinori; Tateiwa, Toshiyuki; Kubo, Kosuke; Endo, Kenji; Aoki, Masaya; Yamamoto, Kengo

    2015-01-01

    The values of hip rotation center (HRC) and femoral offset (FO) evaluated according to Caucasian anatomical landmarks have been regarded as a useful reference also for Japanese patients in total hip arthroplasty (THA). In a strict sense, however, since there can be racial differences among their anatomical morphologies, it is clinically important to reconsider those parameters for the Japanese. In the present study, in order to investigate correlations among hip and pelvic morphometric parameters, frontal radiographs were taken from 98 Japanese adults (60 males and 38 females) without acetabular dysplasia and arthropathy in the standing position. Their mean age was 62.0 ± 16.7 years. The horizontal position of HRC was significantly correlated with the pelvic width in both genders (P = 0.0026 and 0.0010 for the males and the females, resp.). The vertical position of HRC was significantly correlated with the teardrop-sacroiliac distance in the males (P = 0.0003) and with the pelvic cavity height in the females (P = 0.0067). However, in both genders, there were no correlations among FO and the other parameters analyzed in this study. Our present findings might contribute to theoretical implications of an appropriate HRC position for Japanese OA patients in THA. PMID:26576428

  4. Radiographic Determination of Hip Rotation Center and Femoral Offset in Japanese Adults: A Preliminary Investigation toward the Preoperative Implications in Total Hip Arthroplasty

    PubMed Central

    Takamatsu, Taichiro; Shishido, Takaaki; Takahashi, Yasuhito; Masaoka, Toshinori; Tateiwa, Toshiyuki; Kubo, Kosuke; Endo, Kenji; Aoki, Masaya; Yamamoto, Kengo

    2015-01-01

    The values of hip rotation center (HRC) and femoral offset (FO) evaluated according to Caucasian anatomical landmarks have been regarded as a useful reference also for Japanese patients in total hip arthroplasty (THA). In a strict sense, however, since there can be racial differences among their anatomical morphologies, it is clinically important to reconsider those parameters for the Japanese. In the present study, in order to investigate correlations among hip and pelvic morphometric parameters, frontal radiographs were taken from 98 Japanese adults (60 males and 38 females) without acetabular dysplasia and arthropathy in the standing position. Their mean age was 62.0 ± 16.7 years. The horizontal position of HRC was significantly correlated with the pelvic width in both genders (P = 0.0026 and 0.0010 for the males and the females, resp.). The vertical position of HRC was significantly correlated with the teardrop-sacroiliac distance in the males (P = 0.0003) and with the pelvic cavity height in the females (P = 0.0067). However, in both genders, there were no correlations among FO and the other parameters analyzed in this study. Our present findings might contribute to theoretical implications of an appropriate HRC position for Japanese OA patients in THA. PMID:26576428

  5. Normal growth of the "see-through" medaka.

    PubMed

    Iwamatsu, Takashi; Nakamura, Hitomi; Ozato, Kenjiro; Wakamatsu, Yuko

    2003-05-01

    The see-through stock in the medaka Oryzias latipes, causes pigments to be absent from the whole body and has a transparent body in the adult stage as well as during embryonic stages. To establish a standard table of growth stages for this model fish, morphological features were examined during the growing period from hatching to adulthood. The main observations were performed on morphological changes in external and internal organs that could be seen through the body wall of the living fish during growth. Finally, five growth stages from just after hatching to the adult stage were defined on the basis of synchronized or definite changes in morphology as follows: (1) stage 40 in which the nodes (joints) in bony rays of the caudal and pectoral fins first appear, (2) the stage 41 in which the ribs and the anal, dorsal and ventral fins are formed by degeneration of the membrane fin folds, as recognized by the first appearance of nodes in the fin rays of the anal, pectoral and dorsal fins, and the parallel distribution of the dorsal artery and ventral vein of the tail, (3) stage 42 in which the 2-spiral pattern of the gut, the ray nodes in the ventral fins, and the scales first appear, (4) stage 43 in which early secondary sexual characters such as urinogenital protruberances (female) and papillar processes (male) appear, (5) stage 44 in which the 3-spiral pattern of the gut and the papillar process on the 2nd ray of pectral fins (male) appear. PMID:12777831

  6. Developmental exposures to an azole fungicide triadimenol at environmentally relevant concentrations cause reproductive dysfunction in females of medaka fish.

    PubMed

    Chu, Szu-Hung; Liao, Pei-Han; Chen, Pei-Jen

    2016-06-01

    Triadimenol is an effective meatabolite derived from the triazole fungicide triadimenfon. It is an agriculturally important reagent of environmentally emerging concern because of its broad use, persistent occurrence in the environment and greater fungicidal or toxic potency than the parent compound. However, the ecotoxicological impact of triadimenol on fish populations remains unclear. In this study, we investigated developmental toxicity and endocrine disruption effects in medaka fish (Oryzias latipes) exposed at an early life stage to triadimenol. First, mortality, gross development and oxidative stress responses were assessed with triadimenol exposure (3-3000 μg/L) during the embryonic stage. Then, medaka at a sensitive stage of early sexual development underwent 35-day continuous chronic exposure to triadimenol, and the endocrine disruption effects were assessed in adulthood and the next generation. Embryonic exposure to triadimenol did not induce significant teratogenic effects or oxidative stress in embryos or hatchlings. However, early-life exposure to triadimenol under environmentally relevant concentrations (3-30 μg/L) and 300 μg/L persistently altered ovary development and reproduction in female adults and skewed the sex ratio in progeny. As well, triadimenol exposure interrupted the hormone balance, as seen by the expression of genes responsible for estrogen metabolism and egg reproduction. Environmentally relevant triadimenol exposure in medaka fish at early life stages may have ecotoxicological impact in aquatic environments. Along with previous studies, we suggest that conazoles share similar modes of action in disrupting hormone homeostasis and reproduction in fish and mammals. PMID:26971170

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

    NASA Astrophysics Data System (ADS)

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

    2003-10-01

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

  8. Promoter activity of the 5'-flanking regions of medaka fish soluble guanylate cyclase alpha1 and beta1 subunit genes.

    PubMed Central

    Yamamoto, Takehiro; Suzuki, Norio

    2002-01-01

    We examined the spatial expression pattern of medaka fish (Oryzias latipes) soluble guanylate cyclase alpha(1) and beta(1) subunit genes, OlGCS-alpha(1) and OlGCS-beta(1), and characterized the 5'-flanking region required for expression of both genes by introducing various promoter-luciferase fusion-gene constructs into COS-1 cells and medaka fish embryos. The OlGCS-alpha(1) and OlGCS-beta(1) gene transcripts were detected in whole brain and kidney in 7-day and 9-day embryos. Primer-extension analysis demonstrated that there were no differences among various adult organs (brain, eye, kidney, ovary and testis) in the transcription start site of the OlGCS-alpha(1) and OlGCS-beta(1) genes. Neither gene contained the functional TATA box within its 5'-flanking region, and the basal promoter activity was found between nucleotides +33 and +42 in the OlGCS-alpha(1) gene and between nucleotides +146 and +155 in the OlGCS-beta(1) gene. In the assay of medaka fish embryos, the 5'-flanking region of the OlGCS-beta(1) gene exhibited lower promoter activity than that of the OlGCS-alpha(1) gene. In the experiments on dual-luciferase fusion-gene constructs, the 5'-flanking region of the OlGCS-alpha(1) gene connected to the 5'-flanking region of the OlGCS-beta(1) gene was introduced into medaka fish embryos, and the 5'-flanking regions of both subunit genes were shown to mutually influence each other's promoter activity. PMID:11772405

  9. The relationship between traffic noise and insomnia among adult Japanese women

    NASA Astrophysics Data System (ADS)

    Sasazawa, Y.; Kawada, T.; Kiryu, Y.; Suzuki, S.

    2004-10-01

    To clarify the relationship between traffic noise and insomnia, the authors conducted a survey and measured the actual sound level of noise in an urban area. Questionnaires were distributed to adult women who lived within 150 m from two major roads and were completed by 648 of the 1286 subjects (50.4%). The area was divided into three zones according to distance from the road (more than 50, 20-50 and 0-19.9 m). Fifty-seven subjects (8.8%) were classified as having insomnia. Average values of sound level at distances of 20, 50, and 100 m from the major road were Leq 64.7, 57.1, and 51.8 dBA, respectively. Overall, there were no significant differences among the three zones in the prevalence of insomnia and no association between distance from the road and insomnia. However, the result from a sub-data set of the subjects who lived in the areas that showed decreasing noise level as the distance from the main road increased showed that distance from the road was associated with insomnia. This study suggests that researchers should consider the actual traffic situation and its sound level in epidemiological studies about the effects of traffic noise on insomnia.

  10. Statistical analysis of biomechanical properties of the adult sagittal suture using a bending method in a Japanese forensic sample.

    PubMed

    Torimitsu, Suguru; Nishida, Yoshifumi; Takano, Tachio; Koizumi, Yoshinori; Hayakawa, Mutsumi; Yajima, Daisuke; Inokuchi, Go; Makino, Yohsuke; Motomura, Ayumi; Chiba, Fumiko; Iwase, Hirotaro

    2015-04-01

    This study examined the mechanical properties of the adult sagittal suture compared with surrounding parietal bones using bending tests and investigated the association between the mechanical properties of the suture and age. We used the heads of 116 Japanese cadavers (76 male cadavers and 40 female cadavers) of known age and sex. A total of 1160 cranial samples, 10 from each skull, were collected. The samples were imaged using multidetector computed tomography, and the sample thickness at the center of each sample (ST) was measured. The failure stress of each sample (FS) was measured by a bending test, and the ratio of failure stress to the square of sample thickness (FS/ST(2)) was calculated. Statistical analyses revealed that the FS and FS/ST(2) values were significantly lower at all suture sites than at all bone sites regardless of sex. There were not significant but slight positive correlations between age and FS and FS/ST(2) values at any suture site in male samples. In female samples, age had significant positive correlations with FS and FS/ST(2) values at the middle suture sites, whereas there were not significant but slight positive correlations between age and FS and FS/ST(2) values at the edges of the suture. Statistical analyses also demonstrated that FS and FS/ST(2) values were significantly greater in male samples than in female samples at the middle suture sites. These findings suggest that the bending strength of the adult sagittal suture is significantly lower than that of surrounding parietal bones. Therefore, avoiding direct impact on cranial sutures may be important for preventing skull fractures and severe complications that can cause death. The results of this study also revealed that the bending strength of the middle sagittal suture significantly increases with age in only female samples, whereas the bending strength is significantly higher in male samples than in female samples at the middle suture sites, indicating the possibility of sex

  11. Mutation of Gonadal soma-derived factor induces medaka XY gonads to undergo ovarian development.

    PubMed

    Imai, Takuto; Saino, Kentaro; Matsuda, Masaru

    2015-11-01

    Gonochoristic species have a bipotential gonad that develops into a testis or an ovary. In species whose sex is determined by a genetic factor, the expression of a sex-determining gene is the first cue that directs the development of a bipotential gonad. Subsequent expression of downstream genes induces the gonad to develop into a testis or an ovary. The TGF-ß family member Gonadal soma-derived factor (Gsdf) is thought to be an important gene for gonadal development in teleost fish, and it is expressed at higher levels in the testis than in the ovary from early to mature stages. However, there is little functional information about the gene. In this study, we targeted the Gsdf coding region in the medaka fish Oryzias latipes using transcription activator-like effector nucleases (TALENs) and studied the phenotypes of the Gsdf mutant medaka. Although normal and heterozygous XY gonads developed into a testis, all XY gonads with a homozygous mutation in Gsdf developed into an ovary at early developmental stages. However, two-thirds of Gsdf mutant XY gonads developed into testes in the adult stages. These results demonstrate that although a gonad can develop into a complete testis in the absence of Gsdf, Gsdf function is critical for directing the bipotential gonad at early developmental stages. Therefore, Gsdf is an endogenous inducer of testicular development similar to a master sex-determining gene. PMID:26408909

  12. Otolith formation in a mutant Medaka with a deficiency in gravity sensing

    NASA Astrophysics Data System (ADS)

    Mizuno, R.; Ijiri, K.

    2003-10-01

    Mutant Medaka ha exhibit spontaneous mutation that is characterized by frequent inhibition or perturbation in the formation of utricular otoliths and/or semicircular canals. Three major features of otolith morphogenesis were observed in ha strain: 1) The initial appearance of otoliths was delayed, mispositioned, and malformed compared to normal embryos. 2) No utricular otoliths appeared on macula of any ha fry just after hatching. A symmetric state of otoliths was seen only when saccular otoliths were situated on macula in both inner ears. 3) In some fry, formation of utricular otoliths was observed in their later development. However, no new utricular otoliths appeared after fish were seventy or more days old after hatching. These observations show that otolith morphogenesis in ha is very different from that of wild-type. In this study, we classified adult ha into four different phenotypes using the existence or absence of utricular otoliths as our criteria. We concluded that dysfunction of utricular otoliths and semicircular canals cause a defect that affects the gravity-sensing abilities of medaka ha.

  13. Disruption of Circulation by Ethanol Promotes Fetal Alcohol Spectrum Disorder (FASD) in Medaka (Oryzias latipes) Embryogenesis

    PubMed Central

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

    2008-01-01

    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 24h. 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. PMID:18621148

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

    PubMed Central

    2013-01-01

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

  15. Incidences of Herpes Zoster and Postherpetic Neuralgia in Japanese Adults Aged 50 Years and Older From a Community-based Prospective Cohort Study: The SHEZ Study

    PubMed Central

    Takao, Yukiko; Miyazaki, Yoshiyuki; Okeda, Masayuki; Onishi, Fumitake; Yano, Shuichiro; Gomi, Yasuyuki; Ishikawa, Toyokazu; Okuno, Yoshinobu; Mori, Yasuko; Asada, Hideo; Yamanishi, Koichi; Iso, Hiroyasu

    2015-01-01

    Background Many cross-sectional studies have examined the incidences of herpes zoster (HZ) and postherpetic neuralgia (PHN), but prospective studies in Japanese older adults are lacking. Therefore, we conducted a community-based prospective cohort study to determine the incidence in Japanese adults aged ≥50 years. Methods We recruited 12 522 participants from Shozu County, Kagawa Prefecture, between December 2008 and November 2009 and followed participants for 3 years. When a subject presented with symptoms suggestive of HZ, they were examined at collaborating medical institutions and cooperated with onset and recovery surveys (eg, measurement of varicella zoster virus-specific immunity and a pain survey). The hazard ratios (HRs) of HZ and PHN according to sex and age were analyzed by Cox regression analysis with a significance level of 5%. Results The incidence of HZ was 10.9/1000 person-years (men: 8.5/1000 person-years; women: 12.8/1000 person-years) and was significantly higher in women than in men (HR 1.5; 95% confidence interval, 1.2–1.8). The incidence of PHN was 2.1/1000 person-years (men: 1.7/1000 person-years; women: 2.4/1000 person-years), with no significant sex differences. A total of 19% of HZ cases progressed to PHN; no sex-specific difference in the proportion of PHN cases was observed. Conclusions We clarified the accurate incidences of HZ and PHN in a population of Japanese older adults. These incidences increased with age. HZ incidence was higher in women than in men, while PHN incidence did not differ markedly between the sexes. PMID:26399445

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

    PubMed

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

    2011-02-01

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

  17. Genetic similarity of the Hainan medaka populations collected from hyper- and hypo-osmotic environments in northern Vietnam

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hideki; Le, Quang Dung; Kinoshita, Masato; Takehana, Yusuke; Sakuma, Kei; Takeshima, Hirohiko; Kojima, Shigeaki; Naruse, Kiyoshi; Inoue, Koji

    2015-06-01

    Ricefishes of the genus Oryzias, including Japanese medaka ( O. latipes), are known as excellent model organisms for studies in various fields of science. Some species of the genus inhabit brackish water, and such species are recognized to be useful to investigate physiological phenomena in seawater. However, only a limited number of species have been recorded from brackish waters. In addition, there is no information about the genetic relationship among populations inhabiting sites with different salinities. Here we report the discovery of Oryzias fish in two locations near Haiphong, northern Vietnam, a brackish mangrove planting area and a freshwater pond. A phylogenetic analysis using mitochondrial 12S and 16S ribosomal RNA (rRNA) gene sequences indicated that the fish from the two localities are the same species, Hainan medaka, O. curvinotus. Population genetic analysis using the mitochondrial 12S and 16S rRNA gene sequences revealed a close genetic relationship between the two populations. These results suggest that O. curvinotus is adaptable to both hyperosmotic and hypoosmotic environments. Due to its osmotic adaptability and ease of rearing in the laboratory, this species is expected to become a model for marine environmental and toxicological studies, as well as for studies of osmotic adaptation mechanisms.

  18. Ultrasonographic reference sizes of the median and ulnar nerves and the cervical nerve roots in healthy Japanese adults.

    PubMed

    Sugimoto, Takamichi; Ochi, Kazuhide; Hosomi, Naohisa; Mukai, Tomoya; Ueno, Hiroki; Takahashi, Tetsuya; Ohtsuki, Toshiho; Kohriyama, Tatsuo; Matsumoto, Masayasu

    2013-09-01

    The objective of this study was to identify, for practical use, ultrasonographic reference values for nerve sizes at multiple sites, including entrapment and non-entrapment sites along the median and ulnar nerves and among the cervical nerve roots. We verified reliable sites and site-based differences between the reference values. In addition, we found associations between the reference nerve sizes and several physical characteristics (gender, dominant hand, age, height, weight, body mass index [BMI] and wrist circumference). Nerves were measured bilaterally at 26 sites or levels in 60 healthy Japanese adults (29 males; age, 35.4 ± 9.7 y; BMI, 22.3 ± 3.6 kg/m(2); wrist circumference, 16.0 ± 1.3 cm on the right side and 15.9 ± 1.2 cm on the left side). The mean reference nerve sizes were 5.6-9.1 mm(2) along the median nerve, 4.1-6.7 mm(2) along the ulnar nerve and 2.14-3.39 mm among the cervical nerve roots. Multifactorial regression analyses revealed that the physical characteristics most strongly associated with nerve size were age, BMI and wrist circumference at the entrapment sites (F = 7.6, p < 0.01, at the pisiform bone level of the carpal tunnel; F = 15.1, p < 0.001, at the level of Guyon's canal), as well as wrist circumference and gender at the non-entrapment sites (F = 70.6, p < 0.001, along the median nerve; F = 24.7, p < 0.001, along the ulnar nerve). Our results suggest that the factors with the greatest influence on nerve size differed between entrapment and non-entrapment sites. Site-based differences in nerve size were determined using one-way analyses of variance (p < 0.001). Intra- and inter-observer reliability was highest for the median nerve, at both the distal wrist crease and mid-humerus; at the arterial split along the ulnar nerve; and at the fifth cervical nerve root level. No systematic error was indicated by Bland-Altman analysis; the coefficients of variation were 5.5%-9.2% for intra-observer reliability and 7.1%-8.7% for inter

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2009-03-01

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

  2. Japanese encephalitis (JE). Part I: clinical profile of 1,282 adult acute cases of four epidemics.

    PubMed

    Sarkari, N B S; Thacker, A K; Barthwal, S P; Mishra, V K; Prapann, Shiv; Srivastava, Deepak; Sarkari, M

    2012-01-01

    Japanese encephalitis (JE) is numerically the most important global cause of encephalitis and so far confirmed to have caused major epidemics in India. Most of the reported studies have been in children. This largest study involving only adults, belonging to four epidemics, is being reported from Gorakhpur. The aim of this study is to detail the acute clinical profile (not viral) outcome and to classify the sequelae at discharge. This prospective study involved 1,282 adult patients initially diagnosed as JE admitted during the epidemics of 1978, 1980, 1988, and 1989, on identical clinical presentation and CSF examination. In the meantime, the diagnosis of JE was confirmed by serological and/or virological studies in only a representative number of samples (649 of 1,282 cases). Eighty-three left against medical advice (LAMA) at various stages, so 1,199 of 1,282 were available for the study. Peak incidence of [1,061 of 1,282 (83%)] of clinically suspected cases was from September 15 to November 2. Serum IgM and IgG were positive in high titers in 50.87% (330 of 649) and IgM positive in CSF in 88.75% (109 of 123) of the cases. JE virus could be isolated from CSF and brain tissue in 5 of 5 and 4 of 5 samples, respectively. Altered sensorium (AS) in (96%), convulsions (86%), and headache (85%) were the main symptoms for hospitalization by the third day of the onset. Other neurological features included hyperkinetic movements in 593 of 1,282 (46%)-choreoathetoid in 490 (83%) and bizarre, ill-defined in 103 (17%). The features of brain stem involvement consisted of opsoclonus (20%), gaze palsies (16%), and pupillary changes (48%) with waxing and waning character. Cerebellar signs were distinctly absent. Dystonia and decerebrate rigidity was observed in 43 and 6%, respectively, paralytic features in 17% and seizures in 30%. Many non-neurological features of prognostic importance included abnormal breathing patterns (ABP) (45%), pulmonary edema (PO) (33%), and upper

  3. Ultrasound-Derived Forearm Muscle Thickness Is a Powerful Predictor for Estimating DXA-Derived Appendicular Lean Mass in Japanese Older Adults.

    PubMed

    Abe, Takashi; Fujita, Eiji; Thiebaud, Robert S; Loenneke, Jeremy P; Akamine, Takuya

    2016-09-01

    To test the validity of published equations, anterior forearm muscle thickness (MT-ulna) of 158 Japanese older adults (72 men and 86 women) aged 50-79 y was measured with ultrasound. Appendicular lean soft tissue mass (aLM) was estimated from MT-ulna using two equations (body height without [eqn 1] and with [eqn 2]) previously published in the literature. Appendicular lean mass was measured using dual-energy X-ray absorption (DXA), and this method served as the reference criterion. There was a strong correlation between DXA-derived and ultrasound-estimated aLM in both equations (r = 0.882 and r = 0.944). Total error was 2.60 kg for eqn (1) and 1.38 kg for eqn (2). A Bland-Altman plot revealed that there was no systematic bias between DXA-derived and ultrasound-estimated aLM; however, eqn (1) overestimated aLM compared with DXA-derived aLM. Our results suggest that an ultrasound MT-ulna equation that includes body height is appropriate and useful for estimating aLM in Japanese adults. PMID:27321173

  4. The Parapineal Is Incorporated into the Habenula during Ontogenesis in the Medaka Fish.

    PubMed

    Ishikawa, Yuji; Inohaya, Keiji; Yamamoto, Naoyuki; Maruyama, Kouichi; Yoshimoto, Masami; Iigo, Masayuki; Oishi, Tadashi; Kudo, Akira; Ito, Hironobu

    2015-01-01

    The parapineal is present in many teleost families, while it is absent in several others. To find out why the parapineal is absent at adult stages in the latter families, the development of the epithalamus was examined in the medaka fish (Oryzias latipes). For this purpose, a green fluorescent protein-transgenic medaka line, in which the pineal complex (pineal and parapineal) is visible fluorescently, was used. We found that a distinct parapineal was present in the roof plate at early developmental stages. Subsequently, however, the parapineal and the associated roof plate began to be incorporated into the habenula between embryonic stages 28 and 29. Between embryonic stages 29 and 30, the entire parapineal was incorporated into the habenula. That is, the parapineal became a small caudomedial region (termed the 'parapineal domain') within the left habenula in the majority of embryos, resulting in the left-sided asymmetry of the epithalamus. Thereby the left habenula became larger and more complex than its right counterpart. In the minority of embryos, the parapineal was incorporated into the right habenula or into the habenulae on both sides. In the majority of embryos, the parapineal domain projected a fiber bundle to a subnucleus (termed the 'rostromedial subnucleus') in the left habenula. The rostromedial subnucleus sent axons, through the left fasciculus retroflexus, to the rostral region of the left half of the interpeduncular nucleus. We further found that the ratio of the left-sided phenotype was temperature dependent and decreased in embryos raised at a high temperature. The present study is the first demonstration that the supposed lack of a distinct parapineal in adult teleost fishes is due to ontogenetic incorporation into the habenula. PMID:26184391

  5. Things Japanese.

    ERIC Educational Resources Information Center

    Shigeta, Jessie M.

    Presented in this booklet are brief descriptions of items and activities that are symbolic of Japanese culture. Some of the items and activities described include Japanese musical instruments and records, toys and crafts, traditional clothing and accessories, and food utensils. Several recipes for Japanese dishes are provided. Lists of pertinent…

  6. Japanese language and Japanese science

    NASA Astrophysics Data System (ADS)

    Tanikawa, Kiyotaka

    2003-08-01

    Japanese mathematical scientists including astronomers, physicists, and mathematicians obtain ideas in Japanese, discuss their problems in Japanese, and arrive at conclusions in Japanese, and yet they write their results in foreign languages such as English. This uncomfortable situation has continued for nearly one hundred years and has had serious effects on Japanese science. In this short report, the author discusses and analyses these effects. In order to put Japanese science on a sound basis, the author proposes to increase the number of articles, reviews and textbooks in Japanese, first by translation and second by the voluntary efforts of scientists themselves. As centers devoted to this activity, the author proposes to construct "Airborne Libraries" which are maintained and accumulate in an electronic form the scientific documents written in Japanese.

  7. Relationship Between Urinary Concentrations of Nine Water-soluble Vitamins and their Vitamin Intakes in Japanese Adult Males.

    PubMed

    Shibata, Katsumi; Hirose, Junko; Fukuwatari, Tsutomu

    2014-01-01

    Excess water-soluble vitamins are thought to be eliminated in the urine. We have reported a strong relationship between water-soluble vitamin intake and urinary excretion in females. The relationship, however, is not well understood in males. In the present experiment, 10 Japanese male subjects were given a standard Japanese diet for the first week. The subjects remained on the same diet, and a synthesized water-soluble vitamin mixture containing one time the Dietary Reference Intakes (DRIs) for Japanese was given for the second week, three times the DRIs for the third week, and six times the DRIs for the fourth week. Twenty-four-hour urine samples were collected each week. Urinary excretion levels for seven of the nine water-soluble vitamin levels, excluding vitamin B12 and folate, increased linearly and sharply in a dose-dependent manner. These results suggest that measuring urinary water-soluble vitamins can be good nutritional markers for assessing vitamin intakes in humans. PMID:25210461

  8. Relationship Between Urinary Concentrations of Nine Water-soluble Vitamins and their Vitamin Intakes in Japanese Adult Males

    PubMed Central

    Shibata, Katsumi; Hirose, Junko; Fukuwatari, Tsutomu

    2014-01-01

    Excess water-soluble vitamins are thought to be eliminated in the urine. We have reported a strong relationship between water-soluble vitamin intake and urinary excretion in females. The relationship, however, is not well understood in males. In the present experiment, 10 Japanese male subjects were given a standard Japanese diet for the first week. The subjects remained on the same diet, and a synthesized water-soluble vitamin mixture containing one time the Dietary Reference Intakes (DRIs) for Japanese was given for the second week, three times the DRIs for the third week, and six times the DRIs for the fourth week. Twenty-four-hour urine samples were collected each week. Urinary excretion levels for seven of the nine water-soluble vitamin levels, excluding vitamin B12 and folate, increased linearly and sharply in a dose-dependent manner. These results suggest that measuring urinary water-soluble vitamins can be good nutritional markers for assessing vitamin intakes in humans. PMID:25210461

  9. Comparative safety of the antifouling compound butenolide and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) to the marine medaka (Oryzias melastigma).

    PubMed

    Chen, Lianguo; Ye, Rui; Xu, Ying; Gao, Zhaoming; Au, Doris W T; Qian, Pei-Yuan

    2014-04-01

    This study evaluated the potential adverse effects of butenolide, a promising antifouling compound, using the marine medaka (Oryzias melastigma), a model fish for marine ecotoxicology. The active ingredient used in the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) was employed as the positive control. Adult marine medaka (4-month-old) were exposed to various concentrations of butenolide or DCOIT for 28 days and then depurated in clean seawater for 14 days (recovery). A suite of sensitive biomarkers, including hepatic oxidative stress, neuronal signal transmission, endocrine disruption, and reproductive function, was used to measure significant biological effects induced by the chemicals. Compared to DCOIT, chronic exposure to butenolide induced a lower extent of oxidative stress in the liver of male and female medaka. Furthermore, butenolide-exposed fish could recover faster from oxidative stress than fish exposed to DCOIT. Regarding neurotransmission, DCOIT significantly inhibited acetylcholinesterase (AChE) activity in the brain of both male and female medaka, whereas this was not significant for butenolide. In addition, plasma estradiol (E2) level was elevated and testosterone (T) level was decreased in male medaka exposed to DCOIT. This greatly imbalanced sex hormones ratio (E2/T) in exposed males, indicating that DCOIT is a potent endocrine disruptive chemical. In contrast, butenolide induced only moderate effects on sex hormone levels in exposed males, which could be gradually recovered during depuration. Moreover, the endocrine disruptive effect induced by butenolide did not affect normal development of offspring. In contrast, DCOIT-exposed fish exhibited a decrease of egg production and impaired reproductive success. Overall, the above findings demonstrated that chronic exposure to butenolide induced transient, reversible biological effect on marine medaka, while DCOIT could impair reproductive success of fish, as

  10. Confirmation of the factorial structure of the Japanese short version of the TEMPS-A in psychiatric patients and general adults

    PubMed Central

    Nakato, Yasuya; Inoue, Takeshi; Nakagawa, Shin; Kitaichi, Yuji; Kameyama, Rie; Wakatsuki, Yumi; Kitagawa, Kan; Omiya, Yuki; Kusumi, Ichiro

    2016-01-01

    Background The Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Auto-questionnaire (TEMPS-A) is a 110-item questionnaire that assesses five affective temperaments. However, a valid shortened version is desired for large-scale investigations to enhance the compliance of respondents. Methods A confirmatory factor analysis was conducted among 320 psychiatric patients and 61 general adults. The participants completed the Japanese 39-item short version of the TEMPS-A, and a portion of the participants completed the 110-item version. An exploratory factor analysis with the principal factor method and varimax rotation was conducted to identify a more suitable model of the short version of the TEMPS-A. Results The confirmatory factor analysis revealed that the 39-item version exhibited a poor model fit. However, we found that the 18-item version exhibited a firm five-factor structure based on the exploratory factor analysis, and this model exhibited an acceptable model fit. It had good or acceptable internal consistency (Cronbach’s αs: 0.672–0.819). Limitations The majority of the subjects in the present study were patients, and the temperament data may have been affected by psychiatric symptoms. Conclusion A firm five-factor structure was not found in the 39-item short version of the Japanese TEMPS-A. Therefore, an 18-item version was proposed. This new 18-item version of the TEMPS-A might be useful for clinical applications and large-scale investigations. PMID:27601911

  11. Identification of robust hypoxia biomarker candidates from fin of medaka (Oryzias latipes).

    PubMed

    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

    2012-01-01

    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

  12. Comparison of internal doses calculated using the specific absorbed fractions of the average adult Japanese male phantom with those of the reference computational phantom-adult male of ICRP publication 110

    NASA Astrophysics Data System (ADS)

    Manabe, Kentaro; Sato, Kaoru; Endo, Akira

    2014-03-01

    In order to study the effects of body sizes and masses of organs and tissues on internal dose assessment, the values corresponding to effective dose coefficients for intakes of radionuclides were calculated using the specific absorbed fractions (SAFs) of two phantoms: the average adult Japanese male phantom (JM-103) and the reference computational phantom-adult male (RCP-AM) of the International Commission on Radiological Protection. SAFs were evaluated using the phantoms and Monte Carlo radiation transport code MCNPX or were taken from published data. As a result of a comparison for 2894 cases of 923 radionuclides, the maximum discrepancy in the effective dose coefficients between the JM-103 and RCP-AM was about 40%. However, the discrepancies were smaller than 10% in 97% of all cases.

  13. Cryoprotectants protect medaka (Oryzias latipes) embryos from chilling injury.

    PubMed

    Zhang, Qing-Jing; Zhou, Guang-Bin; Wang, Yan-Ping; Fu, Xiang-Wei; Zhu, Shi-En

    2012-01-01

    This study was conducted to investigate the effect of six cryoprotectants (dimethyl sulfoxide (DMSO), glycerol (Gly), methanol (MeOH), ethylene glycol (EG), 1,2-propylene glycol (PG) and N,N-dimethylformamide (DMF) on the survival of medaka (Oryzias lapites) embryos at low temperatures (0 and -5C). Firstly, the embryos at 8 to 16-cell stages were exposed to different concentrations (1 to 4 mol per L) of DMSO, Gly, MeOH, EG, PG and DMF for 40min at 26C. After removal of the cryoprotectants (CPAs), the embryo survivals were assessed by their development into live fries following 9 day of culture. The results showed that the higher concentration of the CPA, the lower survival of the embryos; and that the toxicity of the six CPAs to medaka embryos is in the order of PG < MeOH = DMSO < Gly < EG < DMF (P < 0.05). Secondly, based on the results obtained above, embryos at 8 to 16-cell stages or other stages were exposed to 2 mol per L of PG, MeOH or DMSO for up to 180 min at 0C and up to 80 min at -5C respectively. The 8 to 16-cell embryos treated with MeOH at low temperatures showed highest survival. Thirdly, when embryos at different stages were treated with 2 mol per L of MeOH at -5C for 60 min, 16-somite stage embryos showed highest survival, followed by 4-somite, neurula, 50 percent epiboly, blastula, 32-cell and 8 to 16-cell embryos. These results demonstrated that PG had the lowest toxicity to medaka embryos among the six permeable CPAs at 26C, whereas MeOH showed highest cryoprotective efficiency under chilling conditions and chilling injury decreased gradually with the development of medaka embryos. PMID:22576114

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

    NASA Astrophysics Data System (ADS)

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

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

  15. Super-Protective Child-Rearing by Japanese Bess Beetles, Cylindrocaulus patalis: Adults Provide Their Larvae with Chewed and Predigested Wood.

    PubMed

    Mishima, Tatsuya; Wada, Noriko; Iwata, Ryûtarô; Anzai, Hirosi; Hosoya, Tadatsugu; Araya, Kunio

    2016-01-01

    Beetles of the family Passalidae (Coleoptera: Scarabaeoidea) are termed subsocial. The insects inhabit rotten wood as family groups consisting of the parents and their offspring. The Japanese species Cylindrocaulus patalis has the lowest fecundity among passalids because siblicide occurs among the first-instar larvae; accordingly, parental care toward the survived larva is the highest among Passalidae. To clarify the nutritional relationships between the parents and their offspring, we investigated their ability to digest three types of polysaccharides that are components of wood (cellulose and β-1,4-xylan) and fungal cell walls (β-1,3-glucan). Although carboxymethyl-cellulase activity was barely detectable, β-xylosidase, β-glucosidase, β-1,4-xylanase and β-1,3-glucanase activities were clearly detected in both adults and larvae. Because the activities of enzymes that digest β-1,3-glucan were much higher than those for degrading β-1,4-xylan, in both adults and larvae, it is concluded that they are mainly fungivorous. Furthermore, these digestive enzymatic activities in second- and third-instar larvae were much lower than they were in adults. Although all larval instars grew rapidly when fed chewed wood by their parents, larvae ceased growing and died when fed only artificially ground wood meals. We conclude that the larvae are assumed to be provided with chewed predigested wood in which β-1,3-glucan is degraded by parental enzymes. PMID:27128944

  16. Super-Protective Child-Rearing by Japanese Bess Beetles, Cylindrocaulus patalis: Adults Provide Their Larvae with Chewed and Predigested Wood

    PubMed Central

    Mishima, Tatsuya; Wada, Noriko; Iwata, Ryûtarô; Anzai, Hirosi; Hosoya, Tadatsugu; Araya, Kunio

    2016-01-01

    Beetles of the family Passalidae (Coleoptera: Scarabaeoidea) are termed subsocial. The insects inhabit rotten wood as family groups consisting of the parents and their offspring. The Japanese species Cylindrocaulus patalis has the lowest fecundity among passalids because siblicide occurs among the first-instar larvae; accordingly, parental care toward the survived larva is the highest among Passalidae. To clarify the nutritional relationships between the parents and their offspring, we investigated their ability to digest three types of polysaccharides that are components of wood (cellulose and β-1,4-xylan) and fungal cell walls (β-1,3-glucan). Although carboxymethyl-cellulase activity was barely detectable, β-xylosidase, β-glucosidase, β-1,4-xylanase and β-1,3-glucanase activities were clearly detected in both adults and larvae. Because the activities of enzymes that digest β-1,3-glucan were much higher than those for degrading β-1,4-xylan, in both adults and larvae, it is concluded that they are mainly fungivorous. Furthermore, these digestive enzymatic activities in second- and third-instar larvae were much lower than they were in adults. Although all larval instars grew rapidly when fed chewed wood by their parents, larvae ceased growing and died when fed only artificially ground wood meals. We conclude that the larvae are assumed to be provided with chewed predigested wood in which β-1,3-glucan is degraded by parental enzymes. PMID:27128944

  17. Female mate preference for longer fins in medaka.

    PubMed

    Fujimoto, Shingo; Kawajiri, Maiko; Kitano, Jun; Yamahira, Kazunori

    2014-11-01

    Medaka, Oryzias latipes complex, display sexual dimorphisms in anal- and dorsal-fin lengths that suggest that females may prefer males with longer fins. However, female preference for longer anal and/or dorsal fins has not yet been described for the medaka. One reason that previous studies have not investigated this relationship may be because variations in male fin lengths within a single population are too small to experimentally detect female preference. In this study, we artificially crossed individuals from two wild populations (Aomori and Okinawa) that differed in male anal- and dorsal-fin lengths to increase phenotypic variation. We then tested female mate preference using these hybrid males. The results of the mating experiments and stepwise multiple regression analyses indicate that anal- and/or dorsal-fin lengths of the males contributed to female preference (i.e., males with longer anal and/or dorsal fins were less likely to be rejected by females). Variation in male standard length did not affect female preference. The evolution of female preference for longer fins in the medaka species complex may be explained by the "sexy son" hypothesis or the direct benefit hypothesis. PMID:25366151

  18. Recombinant medaka (Oryzias melastigmus) pro-hepcidin: Multifunctional characterization.

    PubMed

    Cai, Ling; Cai, Jing-Jing; Liu, Hai-Peng; Fan, Dan-Qing; Peng, Hui; Wang, Ke-Jian

    2012-02-01

    Recently, two hepcidin variant genes (Om-hep1 and Om-hep2) were identified in a model fish marine medaka and both were highly induced in vivo with bacterial challenge, suggesting that the medaka hepcidin may have a similar function to other reported teleostean hepcidins. In the present study, the antibacterial, antiviral and antitumor activities of Om-hep1 were determined using its synthetic and recombinant pro-peptides. The recombinant pro-hepcidin1 was expressed in Escherichia coli and an effective method to produce recombinant Pro-Omhep1 was developed in order to obtain a right folded structure. The results showed that both the synthetic mature peptide and recombinant pro-peptide had similar antibacterial activity against Gram-positive and negative bacteria. In particular, both the synthetic mature Om-hep1 and recombinant Pro-Omhep1 inhibited the viral replication of white spot syndrome virus in the hematopoietic tissue cells of the crayfish Cherax quadricarinatus. Om-hep1 also presented antitumor activity on the cultured human hepatocellular carcinoma cells. In addition, the antimicrobial mechanism of Om-hep1 was measured and it was found that Om-hep1 was likely to be non-membranolytic. The recombinant Pro-Omhep1 performed better biological activity compared to the synthetic mature Om-hep1. This study suggested that Om-hep1 was likely to be an important multifunction protein involved in various resistance actions in the marine medaka immune system. PMID:22051539

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

    PubMed

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

    2016-01-01

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

  20. Genetic Analysis of Craniofacial Traits in the Medaka

    PubMed Central

    Kimura, Tetsuaki; Shimada, Atsuko; Sakai, Noriyoshi; Mitani, Hiroshi; Naruse, Kiyoshi; Takeda, Hiroyuki; Inoko, Hidetoshi; Tamiya, Gen; Shinya, Minori

    2007-01-01

    Family and twin studies suggest that a substantial genetic component underlies individual differences in craniofacial morphology. In the current study, we quantified 444 craniofacial traits in 100 individuals from two inbred medaka (Oryzias latipes) strains, HNI and Hd-rR. Relative distances between defined landmarks were measured in digital images of the medaka head region. A total of 379 traits differed significantly between the two strains, indicating that many craniofacial traits are controlled by genetic factors. Of these, 89 traits were analyzed via interval mapping of 184 F2 progeny from an intercross between HNI and Hd-rR. We identified quantitative trait loci for 66 craniofacial traits. The highest logarithm of the odds score was 6.2 for linkage group (LG) 9 and 11. Trait L33, which corresponds to the ratio of head length to head height at eye level, mapped to LG9; trait V15, which corresponds to the ratio of snout length to head width measured behind the eyes, mapped to LG11. Our initial results confirm the potential of the medaka as a model system for the genetic analysis of complex traits such as craniofacial morphology. PMID:18073435

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

    PubMed Central

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

    2016-01-01

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

  2. 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...

  3. INFLUENCE OF EXPOSURE HISTORY ON VITELLOGENIN INDUCTION IN MEDAKA: A CASE OF "ESTROGEN MEMORY"?

    EPA Science Inventory

    Influence of Exposure History on Vitellogenin Induction in Medaka: a Case of "Estrogen Memory"? (Abstract). Mar. Environ. Res. 50(1-5):196.

    In this study, we exposed female medaka to aqueous solutions of o,p'-DDT until tissues residues reached approximately 100 g/g. Male...

  4. A Report of an Adult Case of Tubulointerstitial Nephritis and Uveitis (TINU) Syndrome, with a Review of 102 Japanese Cases

    PubMed Central

    Matsumoto, Keiichiro; Fukunari, Kenichi; Ikeda, Yuji; Miyazono, Motoaki; Kishi, Tomoya; Matsumoto, Ryoko; Fukuda, Makoto; Ichiumi, Saori; Yoshizaki, Mai; Nonaka, Yasunori; Kanaya, Akiko

    2015-01-01

    Patient: Female, 44 Final Diagnosis: Tubulointerstitial nephritis • uveitis syndrome Symptoms: — Medication: Loxoprofen sodium hydrate Clinical Procedure: Renal biopsy Specialty: Nephrology Objective: Rare disease Background: Although TINU syndrome is characterized by idiopathic TIN with bilateral anterior uveitis, few reports have provided a comprehensive summary of the features of this disorder. Previous reports have suggested that many Japanese patients had HLA-A2 and -A24 (7), but there is no evidence. Case Report: A 44-year-old female was referred to our hospital due to renal dysfunction in March 2012. After admission, her symptoms improved spontaneously without medication within 2 weeks. In the outpatient clinic, she was diagnosed with idiopathic bilateral anterior uveitis in May, and her renal dysfunction relapsed in November. A renal biopsy showed diffuse TIN. We made a diagnosis of TINU syndrome because we could not explain the origin, and treated her with a systemic corticosteroid. Her renal function and ocular symptoms have been improving. The patient had HLA-A24, -B7, -DR1, -C*07: 02 and -DQB1*05: 01: 01. We collected 102 Japanese cases in PubMed, Ovid MEDLINE, and the Japanese Medical Abstracts Society and compared our case with the previous cases. Conclusions: This disorder affects primarily young females (median age, 14 years), and the most common symptom is fever (44/102 cases). We conducted a statistical analysis using contingency table and Pearson’s chi-square test, for HLA-A2 and A24, and calculated the odds ratio (OR). There are no significant differences (A2 was present in 7/22 cases and in 19/50 controls, p value (P) 0.61, OR 0.76 (95% confidence interval (CI)) 0.27–2.2; A24 was present in 10/22 cases and in 33/50 controls, P 0.10, OR 0.43, CI 0.16–1.2). PMID:25725230

  5. Two azole fungicides (carcinogenic triadimefon and non-carcinogenic myclobutanil) exhibit different hepatic cytochrome P450 activities in medaka fish.

    PubMed

    Lin, Chun-Hung; Chou, Pei-Hsin; Chen, Pei-Jen

    2014-07-30

    Conazoles are a class of imidazole- or triazole-containing drugs commonly used as fungicides in agriculture and medicine. The broad application of azole drugs has led to the contamination of surface aquifers receiving the effluent of municipal or hospital wastewater or agricultural runoff. Several triazoles are rodent carcinogens; azole pollution is a concern to environmental safety and human health. However, the carcinogenic mechanisms associated with cytochrome P450 enzymes (CYPs) of conazoles remain unclear. We exposed adult medaka fish (Oryzias latipes) to continuous aqueous solutions of carcinogenic triadimefon and non-carcinogenic myclobutanil for 7 to 20 days at sub-lethal or environmentally relevant concentrations and assessed hepatic CYP activity and gene expression associated with CYP-mediated toxicity. Both triadimefon and myclobutanil induced hepatic CYP3A activity, but only triadimefon enhanced CYP1A activity. The gene expression of cyp3a38, cyp3a40, pregnane x receptor (pxr), cyp26b, retinoid acid receptor γ1 (rarγ1) and p53 was higher with triadimefon than myclobutanil. As well, yeast-based reporter gene assay revealed that 4 tested conazoles were weak agonists of aryl hydrocarbon receptor (AhR). We reveal differential CYP gene expression with carcinogenic and non-carcinogenic conazoles in a lower vertebrate, medaka fish. Liver CYP-enzyme induction may be a key event in conazole-induced tumorigenesis. This information is essential to evaluate the potential threat of conazoles to human health and fish populations in the aquatic environment. PMID:24962053

  6. Establishment of oct4:egfp transgenic and oct4:egfp /β-actin:DsRed double transgenic medaka lines.

    PubMed

    Yokota, Shinpei; Matsuno, Rinta; Kato, Hiroyuki; Hashimoto, Hisashi; Kinoshita, Masato; Yokoi, Hayato; Suzuki, Tohru

    2016-06-01

    As a model to examine cellular multipotency in fish, we established a medaka transgenic (Tg) Tru.oct4:egfp line carrying the green fluorescence protein (GFP) cDNA under control of the Takifugu rubripes oct4 promoter. In this Tg line, GFP could be used to examine both maternal and zygotic oct4 expression during embryogenesis. In addition, while adult Tg fish did not express GFP in any somatic cells, activation of GFP expression was initiated in regenerating fins after amputation. In vitro, some of the cell populations that migrated from fin explants expressed GFP, implying that GFP could be used to monitor oct4 expression in both embryos and in regenerating tissues in the Tru.oct4:egfp Tg line. Next, crossing with β-actin:DsRed Tg line in which all cells emit red fluorescence by expression of red fluorescent protein (RFP) under the β-actin promoter, we prepared a Tru.oct4:egfp /β-actin:DsRed double Tg line. In the double Tg line, early embryonic cells were +GFP/+RFP double positive. In vitro fin cell culture, a small number of +GFP/+RFP double positive cells could be discriminated from other -GFP/+RFP cells. Thus, when transplanted into wild-type medaka, this double Tg line can be used to trace the fate of the transplanted cells using RFP fluorescence after the loss of GFP expression. PMID:27067442

  7. Preliminary ecological risk assessment of butylparaben and benzylparaben -1. Removal efficiency in wastewater treatment, acute/chronic toxicity for aquatic organisms, and effects on medaka gene expression.

    PubMed

    Yamamoto, Hiroshi; Watanabe, Mikako; Hirata, Yoshiko; Nakamura, Yuki; Nakamura, Yudai; Kitani, Chise; Sekizawa, Jun; Uchida, Masaya; Nakamura, Hiroshi; Kagami, Yoshihiro; Koshio, Masaaki; Hirai, Narisato; Tatarazako, Norihisa

    2007-01-01

    Butylparaben and benzylparaben, used as preservatives mainly in cosmetic products, have recently been found to be weakly estrogenic. Batch activated-sludge treatment and batch chlorination were carried out to roughly determine the removal efficiency of a wastewater treatment plant. Combining the removal efficiency with the estimated annual consumption and the unaltered excretion ratio, the maximum predicted environmental concentration (PEC) was estimated. Conventional acute/chronic toxicity tests were conducted using Japanese medaka (Oryzias latipes), daphnia (Daphnia magna), and green algae (Pseudokirchneriella subcapitata) for n-butylparaben, i-butylparaben, and benzylparaben. Medaka vitellogenin assays were also conducted for the three compounds and DNA microarray analysis was carried out to examine the effects of benzylparaben on gene expression. The plasma vitellogenin concentration of male medaka increased for concentrations of 200, 100, and 100 microg L(-1) n-butylparaben, i-butylparaben, and benzylparaben for 14 days, respectively, while the expression levels of genes encoding proteins such as p53, cytochrome P450 3A40, and choriogenin-L increased for concentrations higher than 4 microg L(-1) of benzylparaben. Furthermore, the predicted no-effect concentration (PNEC) was calculated using the lethal or effect concentration 50 (LC50 or EC50) values and no-effect concentrations (NOECs) obtained in the toxicity tests for these compounds. The maximum concentrations found in the aquatic environment or sewage effluent (MEC eff) were used to carry out preliminary environmental risk assessment. The calculated MEC/PNEC ratio suggests the necessity of further study such as a more detailed large-scale monitoring and chronic toxicity tests including reproduction inhibition and endocrine disruption. PMID:18382416

  8. When Ontogeny Matters: A New Japanese Species of Brittle Star Illustrates the Importance of Considering both Adult and Juvenile Characters in Taxonomic Practice.

    PubMed

    Martynov, Alexander; Ishida, Yoshiaki; Irimura, Seiichi; Tajiri, Rie; O'Hara, Timothy; Fujita, Toshihiko

    2015-01-01

    Current taxonomy offers numerous approaches and methods for species delimitation and description. However, most of them are based on the adult characters and rarely suggest a dynamic representation of developmental transformations of taxonomically important features. Here we show how the underestimation of ontogenetic changes may result in long term lack of recognition of a new species of one of the most common ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the North Pacific. Based on vast material collected predominantly by various Japanese expeditions in the course of more than 50 years, and thorough study of appropriate type material, we revise the complex of three common species of the ophiuroid genus Ophiacantha which have been persistently confused with each other. The present study thus reveals the previously unrecognized new species Ophiacantha kokusai sp.nov. which is commonly distributed off the Pacific coast of Japan. The new species shows developmental differentiation from the closely related species Ophiacantha rhachophora H. L. Clark, 1911 and retains clearly expressed early juvenile features in the adult morphology. Another species, Ophiacantha clypeata Kyte, 1977, which had been separated from O. rhachophora, is in turn shown to be just a juvenile stage of another North Pacific species, Ophiacantha trachybactra H.L. Clark, 1911. For every species, detailed morphological data from both adult and juvenile specimens based on scanning electron microscopy are presented. A special grinding method showing complex internal features has been utilized for the first time. For all three species in this complex, a clear bathymetric differentiation is revealed: O. rhachophora predominantly inhabits shallow waters, 0-250 m, the new species O. kokusai lives deeper, at 250-600 m, and the third species, O. trachybactra, is found at 500-2,000 m. The present case clearly highlights the importance of considering developmental transformations, not only for

  9. When Ontogeny Matters: A New Japanese Species of Brittle Star Illustrates the Importance of Considering both Adult and Juvenile Characters in Taxonomic Practice

    PubMed Central

    Martynov, Alexander; Ishida, Yoshiaki; Irimura, Seiichi; Tajiri, Rie; O’Hara, Timothy; Fujita, Toshihiko

    2015-01-01

    Current taxonomy offers numerous approaches and methods for species delimitation and description. However, most of them are based on the adult characters and rarely suggest a dynamic representation of developmental transformations of taxonomically important features. Here we show how the underestimation of ontogenetic changes may result in long term lack of recognition of a new species of one of the most common ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the North Pacific. Based on vast material collected predominantly by various Japanese expeditions in the course of more than 50 years, and thorough study of appropriate type material, we revise the complex of three common species of the ophiuroid genus Ophiacantha which have been persistently confused with each other. The present study thus reveals the previously unrecognized new species Ophiacantha kokusai sp.nov. which is commonly distributed off the Pacific coast of Japan. The new species shows developmental differentiation from the closely related species Ophiacantha rhachophora H. L. Clark, 1911 and retains clearly expressed early juvenile features in the adult morphology. Another species, Ophiacantha clypeata Kyte, 1977, which had been separated from O. rhachophora, is in turn shown to be just a juvenile stage of another North Pacific species, Ophiacantha trachybactra H.L. Clark, 1911. For every species, detailed morphological data from both adult and juvenile specimens based on scanning electron microscopy are presented. A special grinding method showing complex internal features has been utilized for the first time. For all three species in this complex, a clear bathymetric differentiation is revealed: O. rhachophora predominantly inhabits shallow waters, 0–250 m, the new species O. kokusai lives deeper, at 250–600 m, and the third species, O. trachybactra, is found at 500–2,000 m. The present case clearly highlights the importance of considering developmental transformations, not

  10. Bioconcentration of Dissolved Organic Compounds from Oil Sands Process-Affected Water by Medaka (Oryzias latipes): Importance of Partitioning to Phospholipids.

    PubMed

    Zhang, Kun; Wiseman, Steve; Giesy, John P; Martin, Jonathan W

    2016-06-21

    The complex mixture of dissolved organics in oil sands process-affected water (OSPW) is acutely lethal to fish at environmentally relevant concentrations, but few bioconcentration factors (BCFs) have been measured for its many chemical species. Japanese medaka (Oryzias latipes) were exposed to 10% OSPW, and measured BCFs were evaluated against predicted BCFs from octanol-water distribution ratios (DOW) and phospholipid membrane-water distribution ratios (DMW). Two heteroatomic chemical classes detected in positive ion mode (SO(+), NO(+)) and one in negative mode (O2(-), also known as naphthenic acids) had the greatest DMW values, as high as 10 000. Estimates of DMW were similar to and correlated with DOW for O(+), O2(+), SO(+), and NO(+) chemical species, but for O2(-) and SO2(-) species the DMW values were much greater than the corresponding DOW, suggesting the importance of electrostatic interactions for these ionizable organic acids. Only SO(+), NO(+), and O2(-) species were detectable in medaka exposed to OSPW, and BCFs for SO(+) and NO(+) species ranged from 0.6 to 28 L/kg, lower than predicted (i.e., 1.4-1.7 × 10(3) L/kg), possibly because of biotransformation of these hydrophobic substances. BCFs of O2(-) species ranged from 0.7 to 53 L/kg, similar to predicted values and indicating that phospholipid partitioning was an important bioconcentration mechanism. PMID:27224302

  11. Diethylnitrosamine-induced expression of germline-specific genes and pluripotency factors, including vasa and oct4, in medaka somatic cells.

    PubMed

    Shen, Jialing; Yokota, Shinpei; Yokoi, Hayato; Suzuki, Tohru

    2016-09-16

    Various methods have been developed to reprogram mammalian somatic cells into pluripotent cells as well as to directly reprogram somatic cells into other cell lineages. We are interested in applying these methods to fish, and here, we examined whether mRNA expression of germline-specific genes (vasa, nanos2, -3) and pluripotency factors (oct4, sox2, c-myc, nanog) is inducible in somatic cells of Japanese medaka (Oryzias latipes). We found that the expression of vasa is induced in the gut and regenerating fin by exposure to a carcinogen, diethylnitrosamine (DEN). Induction of vasa in the gut started on the 5th day of treatment with >50 ppm DEN. In addition, nanos2, -3, oct4, sox2, klf4, c-myc, and nanog were also expressed simultaneously in some vasa-positive gut and regenerating fin samples. Vasa-positive cells were detected by immunohistochemistry (IHC) in the muscle surrounding the gut and in the wound epidermis, blastema, and fibroblast-like cells in regenerating fin. In vasa:GFP transgenic medaka, green fluorescent protein (GFP) fluorescence appeared in the wound epidermis and fibroblast-like cells in the regenerating fin following DEN exposure, in agreement with the IHC data. Our data show that mRNA expression of genes relevant to germ cell specification and pluripotency can be induced in fish somatic cells by exposure to DEN, suggesting the possibility of efficient and rapid cell reprogramming of fish somatic cells. PMID:27514449

  12. Development of realistic high-resolution whole-body voxel models of Japanese adult males and females of average height and weight, and application of models to radio-frequency electromagnetic-field dosimetry

    NASA Astrophysics Data System (ADS)

    Nagaoka, Tomoaki; Watanabe, Soichi; Sakurai, Kiyoko; Kunieda, Etsuo; Watanabe, Satoshi; Taki, Masao; Yamanaka, Yukio

    2004-01-01

    With advances in computer performance, the use of high-resolution voxel models of the entire human body has become more frequent in numerical dosimetries of electromagnetic waves. Using magnetic resonance imaging, we have developed realistic high-resolution whole-body voxel models for Japanese adult males and females of average height and weight. The developed models consist of cubic voxels of 2 mm on each side; the models are segmented into 51 anatomic regions. The adult female model is the first of its kind in the world and both are the first Asian voxel models (representing average Japanese) that enable numerical evaluation of electromagnetic dosimetry at high frequencies of up to 3 GHz. In this paper, we will also describe the basic SAR characteristics of the developed models for the VHF/UHF bands, calculated using the finite-difference time-domain method.

  13. The Overnight Effect of Dietary Energy Balance on Postprandial Plasma Free Amino Acid (PFAA) Profiles in Japanese Adult Men

    PubMed Central

    Nishioka, Manabu; Imaizumi, Akira; Ando, Toshihiko; Tochikubo, Osamu

    2013-01-01

    The plasma free amino acid (PFAA) profile is affected by various nutritional conditions, such as the dietary energy balance. Regarding the clinical use of PFAA profiling, it is of concern that differences in food ingestion patterns may generate systematic errors in a plasma amino acid profile and constitute a confounding factor in assessment. In this study, the overnight impact of the dietary energy balance on the postprandial plasma amino acid profile was investigated to elucidate in particular the effects of high protein meals typical in Japanese cuisine. We conducted diet-controlled, crossover trials in eleven healthy male volunteers aged 40–61 y. They consumed either a normal meal (meal N) or high protein meal (meal H) at dinner. Forearm venous blood was collected, and plasma amino acid concentrations were measured before dinner and the next morning. We found that a high protein meal in the evening that contained 40% energy would significantly increase the PFAA concentration the next morning, even more than 12 hours after the meal. Among amino acids, the most significant difference was observed in the branched-chain amino acids (BCAAs) and in some urea-cycle related compounds. If the subject consumed the high protein diet at dinner, the PFAA profile after overnight fasting might be still affected by the meal even 12 hours after the meal, suggesting that the PFAA profile does not reflect the subject's health condition, but rather the acute effect of high protein ingestion. PMID:23667542

  14. Neighborhood food environment and body mass index among Japanese older adults: results from the Aichi Gerontological Evaluation Study (AGES)

    PubMed Central

    2011-01-01

    Background The majority of studies of the local food environment in relation to obesity risk have been conducted in the US, UK, and Australia. The evidence remains limited to western societies. The aim of this paper is to examine the association of local food environment to body mass index (BMI) in a study of older Japanese individuals. Methods The analysis was based on 12,595 respondents from cross-sectional data of the Aichi Gerontological Evaluation Study (AGES), conducted in 2006 and 2007. Using Geographic Information Systems (GIS), we mapped respondents' access to supermarkets, convenience stores, and fast food outlets, based on a street network (both the distance to the nearest stores and the number of stores within 500 m of the respondents' home). Multiple linear regression and logistic regression analyses were performed to examine the association between food environment and BMI. Results In contrast to previous reports, we found that better access to supermarkets was related to higher BMI. Better access to fast food outlets or convenience stores was also associated with higher BMI, but only among those living alone. The logistic regression analysis, using categorized BMI, showed that the access to supermarkets was only related to being overweight or obese, but not related to being underweight. Conclusions Our findings provide mixed support for the types of food environment measures previously used in western settings. Importantly, our results suggest the need to develop culture-specific approaches to characterizing neighborhood contexts when hypotheses are extrapolated across national borders. PMID:21777439

  15. The Role of Spirituality in Learning Music: A Case of North American Adult Students of Japanese Music

    ERIC Educational Resources Information Center

    Matsunobu, Koji

    2012-01-01

    In this paper the role of spirituality in learning music for North American adult students is explored by examining the case of shakuhachi music. One distinctive character of engaging in music through the shakuhachi is that it facilitates the attainment of an "optimal relationship" between the practitioners" musical pursuit and self-cultivation…

  16. 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

  17. Association of Oral Fat Sensitivity with Body Mass Index, Taste Preference, and Eating Habits in Healthy Japanese Young Adults.

    PubMed

    Asano, Masanobu; Hong, Guang; Matsuyama, Yusuke; Wang, Weiqi; Izumi, Satoshi; Izumi, Masayuki; Toda, Takashi; Kudo, Tada-Aki

    2016-01-01

    Oral fat sensitivity (OFS, the ability to detect fat) may be related to overeating-induced obesity. However, it is largely unknown whether OFS affects taste preference and eating habits. Therefore, we aimed to evaluate (1) the association between body mass index (BMI) and OFS and (2) the relationship of OFS with four types of taste preference (sweet, sour, salty, and bitter) and eating habits using serial concentrations of oleic acid (OA) homogenized in non-fat milk and a self-reported questionnaire. Participants were 25 healthy Japanese individuals (mean age: 27.0 ± 5.6 years), among whom the OA detection threshold was significantly associated with BMI. Participants were divided into two subgroups based on oral sensitivity to 2.8 mM OA: hypersensitive (able to detect 2.8 mM OA, n = 16) and hyposensitive (unable to detect 2.8 mM OA, n = 9). The degree of sweet taste preference of the hypersensitive group was significantly higher than that of the hyposensitive group. Furthermore, there was significantly higher degree of preference for high-fat sweet foods than low-fat sweet foods in the hypersensitive group. There was also a significant inverse correlation between the OA detection threshold and the degree of both spare eating and postprandial satiety. Thus, OFS is associated not only with BMI, but also with the preference for high-fat sweet foods and eating habits. The present study provides novel insights that measuring OFS may be useful for assessing the risk of obesity associated with overeating in countries, including Japan, where BMI is increasing in the population. PMID:26797054

  18. Smoking, Smoking Cessation, and the Risk of Type 2 Diabetes among Japanese Adults: Japan Epidemiology Collaboration on Occupational Health Study

    PubMed Central

    Akter, Shamima; Okazaki, Hiroko; Kuwahara, Keisuke; Miyamoto, Toshiaki; Murakami, Taizo; Shimizu, Chii; Shimizu, Makiko; Tomita, Kentaro; Nagahama, Satsue; Eguchi, Masafumi; Kochi, Takeshi; Imai, Teppei; Nishihara, Akiko; Sasaki, Naoko; Nakagawa, Tohru; Yamamoto, Shuichiro; Honda, Toru; Uehara, Akihiko; Yamamoto, Makoto; Hori, Ai; Sakamoto, Nobuaki; Nishiura, Chiro; Totsuzaki, Takafumi; Kato, Noritada; Fukasawa, Kenji; Pham, Ngoc M.; Kurotani, Kayo; Nanri, Akiko; Kabe, Isamu; Mizoue, Tetsuya; Sone, Tomofumi; Dohi, Seitaro

    2015-01-01

    Aims To examine the association of smoking status, smoking intensity, and smoking cessation with the risk of type 2 diabetes (T2D) using a large database. Methods The present study included 53,930 Japanese employees, aged 15 to 83 years, who received health check-up and did not have diabetes at baseline. Diabetes was defined as fasting plasma glucose ≥126 mg/dl, random plasma glucose ≥200 mg/dl, HbA1c ≥6.5% (≥48 mmol/mol), or receiving medication for diabetes. Cox proportional-hazards regression models were used to investigate the association between smoking and the risk of diabetes. Results During 3.9 years of median follow-up, 2,441 (4.5%) individuals developed T2D. The multivariable-adjusted hazard ratios (95% CI) for diabetes were 1 (reference), 1.16 (1.04 to 1.30) and 1.34 (1.22 to 1.48) for never smokers, former smokers, and current smokers, respectively. Diabetes risk increased with increasing numbers of cigarette consumption among current smokers (P for trend <0.001). Although the relative risk of diabetes was greater among subjects with lower BMIs (< 23 kg/m2), attributable risk was greater in subjects with higher BMIs (≥ 23 kg/m2). Compared with individuals who had never smoked, former smokers who quit less than 5 years, 5 to 9 years, and 10 years or more exhibited hazards ratios for diabetes of 1.36 (1.14 to 1.62), 1.23 (1.01 to 1.51), and 1.02 (0.85 to 1.23), respectively. Conclusions Results suggest that cigarette smoking is associated with an increased risk of T2D, which may decrease to the level of a never smoker after 10 years of smoking cessation. PMID:26200457

  19. Targeted mutagenesis using CRISPR/Cas system in medaka

    PubMed Central

    Ansai, Satoshi; Kinoshita, Masato

    2014-01-01

    ABSTRACT Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system-based RNA-guided endonuclease (RGEN) has recently emerged as a simple and efficient tool for targeted genome editing. In this study, we showed successful targeted mutagenesis using RGENs in medaka, Oryzias latipes. Somatic and heritable mutations were induced with high efficiency at the targeted genomic sequence on the DJ-1 gene in embryos that had been injected with the single guide RNA (sgRNA) transcribed by a T7 promoter and capped RNA encoding a Cas9 nuclease. The sgRNAs that were designed for the target genomic sequences without the 5′ end of GG required by the T7 promoter induced the targeted mutations. This suggests that the RGEN can target any sequence adjacent to an NGG protospacer adjacent motif (PAM) sequence, which occurs once every 8 bp. The off-target alterations at 2 genomic loci harboring double mismatches in the 18-bp targeting sequences were induced in the RGEN-injected embryos. However, we also found that the off-target effects could be reduced by lower dosages of sgRNA. Taken together, our results suggest that CRISPR/Cas-mediated RGENs may be an efficient and flexible tool for genome editing in medaka. PMID:24728957

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  2. Association of oxytocin level and less severe forms of childhood maltreatment history among healthy Japanese adults involved with child care

    PubMed Central

    Mizuki, Rie; Fujiwara, Takeo

    2015-01-01

    Background: Oxytocin (OT) is known to play a role in stress regulation. The association between childhood maltreatment history and neuropeptide OT concentration is inconsistent due to the varying degrees of severity of childhood maltreatment, among other contributing factors. Less severe forms of childhood maltreatment history might enhance OT concentrations as a response to coping with social stress within the family. The purpose of this study is to investigate the association between less severe forms of childhood maltreatment history and OT concentrations among healthy adults. Method: Eighty adults (49 women and 31 men) with 18- to 48-month-old children were recruited using a snowball sample in Tokyo, Japan. Urine samples were collected for OT measurement. Less severe (low and moderate) childhood maltreatment history, including physical abuse, physical neglect, emotional abuse, emotional neglect, and sexual abuse, was assessed using the self-report questionnaire, the Childhood Trauma Questionnaire. Results: Less severe physical abuse was significantly associated with higher OT concentration after adjusting for age (p = 0.014). Also, less severe forms of physical abuse were independently significantly associated with higher OT concentration after controlling for other types of childhood maltreatment (p = 0.027). A positive dose-response association between the number of less severe childhood maltreatment types and OT concentration was observed (p = 0.031). Conclusion: A history of less severe forms of childhood physical abuse was associated with higher OT concentration in healthy adults. Poly-victimization of several types of less severe childhood maltreatment was also associated with higher OT concentrations. Less severe forms of childhood maltreatment might enhance OT concentrations in order to cope with social stress. PMID:26157369

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

    PubMed

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

    2016-02-01

    In recent years, the marine medaka (Oryzias melastigma), also known as the Indian medaka or brackish medaka, has been recognized as a model fish species for ecotoxicology and environmental research in the Asian region. O. melastigma has several promising features for research, which include a short generation period (3-4 months), daily spawning, small size (3-4 cm), transparent embryos, sexual dimorphism, and ease of mass culture in the laboratory. There have been extensive transcriptome and genome studies on the marine medaka in the past decade. Such omics data can be useful in understanding the signal transduction pathways of small teleosts in response to environmental stressors. An omics-integrated approach in the study of the marine medaka is important for strengthening its role as a small fish model for marine environmental studies. In this review, we present current omics information about the marine medaka and discuss its potential applications in the study of various molecular pathways that can be targets of marine environmental stressors, such as chemical pollutants. We believe that this review will encourage the use of this small fish as a model species in marine environmental research. PMID:26716363

  4. GFP Transgenic Medaka (Oryzias latipes) under the Inducible cyp1a Promoter Provide a Sensitive and Convenient Biological Indicator for the Presence of TCDD and Other Persistent Organic Chemicals

    PubMed Central

    Ng, Grace Hwee Boon; Gong, Zhiyuan

    2013-01-01

    Persistent organic pollutants (POPs) are resistant to environmental degradation and can cause multitude of health problems. Cytochrome P450 1A (Cyp1a) is often up-regulated by POPs through the activation of aryl hydrocarbon receptor (AhR) pathway and is thus usually used as a biomarker for xenobiotics exposure. To develop a convenient in vivo tool to monitor xenobiotic contamination in the water, we have established GFP transgenic medaka using the inducible cyp1a promoter, Tg(cyp1a:gfp). Here we tested Tg(cyp1a:gfp) medaka at three different stages, prehatching embryos, newly hatched fry and adult with 2,3,7,8-tetrachlorodiebnzo-p-dioxin (TCDD), a dioxin. While GFP induction was observed in all three stages, newly hatched fry were the most sensitive with the lowest observed effective concentration of 0.005 nM or 16.1 ng/L. The highly sensitive organs included the kidney, liver and intestine. With high concentrations of TCDD, several other organs such as the olfactory pit, tail fin, gills, lateral line neuromast cells and blood vessels also showed GFP expression. In addition, Tg(cyp1a:gfp) medaka fry also responded to two other AhR agonists, 3-methylcholanthrene and benzo[a]pyrene, for GFP induction, but no significant GFP induction was observed towards several other chemicals tested, indicating the specificity of this transgenic line. The GFP inducibility of Tg(cyp1a:gfp) medaka at both fry and adult stages may be useful for development of high-throughput assays as well as online water monitoring system to detect xenobiotic toxicity. PMID:23700472

  5. Purification and molecular cloning of aspartic proteinases from the stomach of adult Japanese fire belly newts, Cynops pyrrhogaster.

    PubMed

    Nagasawa, Tatsuki; Sano, Kaori; Kawaguchi, Mari; Kobayashi, Ken-Ichiro; Yasumasu, Shigeki; Inokuchi, Tomofumi

    2016-04-01

    Six aspartic proteinase precursors, a pro-cathepsin E (ProCatE) and five pepsinogens (Pgs), were purified from the stomach of adult newts (Cynops pyrrhogaster). On sodium dodecylsulfate-polyacrylamide gel electrophoresis, the molecular weights of the Pgs and active enzymes were 37-38 kDa and 31-34 kDa, respectively. The purified ProCatE was a dimer whose subunits were connected by a disulphide bond. cDNA cloning by polymerase chain reaction and subsequent phylogenetic analysis revealed that three of the purified Pgs were classified as PgA and the remaining two were classified as PgBC belonging to C-type Pg. Our results suggest that PgBC is one of the major constituents of acid protease in the urodele stomach. We hypothesize that PgBC is an amphibian-specific Pg that diverged during its evolutional lineage. PgBC was purified and characterized for the first time. The purified urodele pepsin A was completely inhibited by equal molar units of pepstatin A. Conversely, the urodele pepsin BC had low sensitivity to pepstatin A. In acidic condition, the activation rates of newt pepsin A and BC were similar to those of mammalian pepsin A and C1, respectively. Our results suggest that the enzymological characters that distinguish A- and C-type pepsins appear to be conserved in mammals and amphibians. PMID:26711235

  6. Radiation doses received by adult Japanese populations living outside Fukushima Prefecture during March 2011, following the Fukushima 1 nuclear power plant failures.

    PubMed

    Priest, N D

    2012-12-01

    Data on the concentration of radionuclides in air for March following the reactor failures at the Fukushima NPP were available for Takasaki, Chiba and Tokyo. Gamma dose data for the same/close locations and for fixed locations in other prefectures were also obtained. Gamma dose data was used to calculate the cumulative gamma dose, during 2 weeks (15th-28th March) following the power plant failures. Corresponding doses were calculated for sites in other Japanese prefectures - except Fukushima Prefecture, for which equivalent monitoring data was not published. For Takasaki, Chiba and Tokyo air concentration data and ICRP dose coefficients were used to calculate inhalation committed effective doses (CED, E(50)) and thyroid equivalent doses (H) for adult members of the public. Average ratios of gamma dose to inhalation CED and inhalation CED from iodine isotopes to thyroid equivalent dose, determined for Takasaki, Chiba and Tokyo, were then used to predict these quantities for sites in other prefectures. Cumulative gamma dose profiles were used to identify dose increments that could be attributed to Fukushima releases within 11 prefectures (excluding Fukushima Prefecture). The most impacted of these were located in Gunma, Ibaraki, Tochigi and Saitama Prefectures - to the south of Fukushima - and in Miyagi Prefecture - to the north of Fukushima. Calculated total doses ranged from 16 μSv in Shizuoka (Shizuoka) to 400 μSv in Ibaraki (Mito). The total doses calculated for the major population centres of Tokyo and Chiba were 97 μSv and 80 μSv, respectively. For all prefecture locations the largest calculated contribution to total dose, during the period of assessment, was from inhalation (~80%). Estimated thyroid equivalent doses ranged from 5.9 mSv in Ibaraki to 200 μSv in Shizuoka. All total doses calculated were probably overestimates - since no allowances were made for shielding and shelter during the passage of radioactive clouds. Minor contributions to dose from

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

    PubMed Central

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

    2012-01-01

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

  8. Neoplastic and nonneoplastic liver lesions induced by dimethylinitrosamine in Japanese Medaka fish

    EPA Science Inventory

    Small fish models are becoming commonplace in the laboratory, and have been used for decades in chemical toxicity and carcinogenicity testing. However, extrapolation of findings from aquatic models to humans is still a concern in risk assessment. Demonstration of common morpholog...

  9. 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...

  10. 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.

  11. 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 ...

  12. Irradiation-injured brain tissues can self-renew in the absence of the pivotal tumor suppressor p53 in the medaka (Oryzias latipes) embryo

    PubMed Central

    Yasuda, Takako; Kimori, Yoshitaka; Nagata, Kento; Igarashi, Kento; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-01-01

    The tumor suppressor protein, p53, plays pivotal roles in regulating apoptosis and proliferation in the embryonic and adult central nervous system (CNS) following neuronal injuries such as those induced by ionizing radiation. There is increasing evidence that p53 negatively regulates the self-renewal of neural stem cells in the adult murine brain; however, it is still unknown whether p53 is essential for self-renewal in the injured developing CNS. Previously, we demonstrated that the numbers of apoptotic cells in medaka (Oryzias latipes) embryos decreased in the absence of p53 at 12–24 h after irradiation with 10-Gy gamma rays. Here, we used histology to examine the later morphological development of the irradiated medaka brain. In p53-deficient larvae, the embryonic brain possessed similar vacuoles in the brain and retina, although the vacuoles were much smaller and fewer than those found in wild-type embryos. At the time of hatching (6 days after irradiation), no brain abnormality was observed. In contrast, severe disorganized neuronal arrangements were still present in the brain of irradiated wild-type embryos. Our present results demonstrated that self-renewal of the brain tissue completed faster in the absence of p53 than wild type at the time of hatching because p53 reduces the acute severe neural apoptosis induced by irradiation, suggesting that p53 is not essential for tissue self-renewal in developing brain. PMID:26410759

  13. 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. PMID:15667848

  14. Toxic responses of medaka, d-rR strain, to polychlorinated naphthalene mixtures after embryonic exposure by in ovo nanoinjection: A partial life- cycle assessment

    USGS Publications Warehouse

    Villalobos, Sergio A.; Papoulias, D.M.; Meadows, J.; Blankenship, Alan L.; Pastva, Stephanie D.; Kannan, K.; Hinton, D.E.; Tillitt, D.E.; Giesy, J.P.

    2000-01-01

    Polychlorinated naphthalenes (PCNs) are organic compounds with some chemical properties and uses similar to polychlorinated biphenyls. Polychlorinated naphthalenes have been detected in biota from certain aquatic environments. The toxicities of several PCN technical mixtures (Halowax) to medaka (Oryzias latipes) were determined by use of an embryo nanoinjection method. Medaka eggs (early gastrula) were injected with 0.5 nl of triolein (vehicle control) or 0.5 nl of four to five graded doses (0.3-30 ng/egg) of Halowax 1014, Halowax 1013, or Halowax 1051 in triolein. Following exposure, embryos developed, and fry were reared to sexual maturity (4 months), at which time they were euthanized. Responses were evaluated as early life stage (ELS) and early adult life stage (EALS) assessments. For ELS, lethality and sublethal alterations in embryos and larvae (<16 d old), such as craniofacial, cardiovascular, and myoskeletal deformities and abnormal or delayed hatch, were monitored for the first 9 d, and a dose severity index was computed. The EALS assessment examined the survival of 16-d-old larvae until early adulthood (123 ?? 3 d old), including gonadosomatic index (GSI) and morphometry. Halowax 1014 was found to be the most toxic mixture (LD50 4.2 ng/egg), whereas Halowax 1013 and 1051 were significantly less toxic (LD50s could not be determined). The gonadosomatic index of females was significantly less in fish dosed with Halowax 1014 or 1051. The LD50 for medaka embryos nanoinjected with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is about 0.75 pg/egg. Thus, Halowax 1014 was 5,585-fold less potent than TCDD. For Halowax 1014, ELS assessments accurately predicted the results of EALS assessments.

  15. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma.

    PubMed

    Wang, Jian; Wang, Wen-Xiong

    2016-01-01

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0-640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6-18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3-15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046-0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71-1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09-2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88-0.90 μg/g/d. PMID:27216705

  16. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Wang, Wen-Xiong

    2016-05-01

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0–640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6–18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3–15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046–0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71–1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09–2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88–0.90 μg/g/d.

  17. Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma

    PubMed Central

    Wang, Jian; Wang, Wen-Xiong

    2016-01-01

    Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0–640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6–18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3–15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046–0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71–1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09–2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88–0.90 μg/g/d. PMID:27216705

  18. Japanese Characters in Written Japanese.

    ERIC Educational Resources Information Center

    Buck, James H.

    From the sixth to the eighth century A.D., Japan was the recipient of massive cultural infusions from China. This acceptance of the Chinese pattern included, and to a great extent was based on, the acceptance of the Chinese language. The Chinese writing system was applied to Japanese because there was no other model to follow and in spite of the…

  19. 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

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

    PubMed Central

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

    2012-01-01

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

  1. Development of Text Reading in Japanese: An Eye Movement Study

    ERIC Educational Resources Information Center

    Jincho, Nobuyuki; Feng, Gary; Mazuka, Reiko

    2014-01-01

    This study examined age-group differences in eye movements among third-grade, fifth-grade, and adult Japanese readers. In Experiment 1, Japanese children, but not adults, showed a longer fixation time on logographic kanji words than on phonologically transparent hiragana words. Further, an age-group difference was found in the first fixation…

  2. Independent analysis of the radiation risk for leukaemia in children and adults with mortality data (1950-2003) of Japanese A-bomb survivors.

    PubMed

    Kaiser, Jan Christian; Walsh, Linda

    2013-03-01

    A recent analysis of leukaemia mortality in Japanese A-bomb survivors has applied descriptive models, collected together from previous studies, to derive a joint excess relative risk estimate (ERR) by multi-model inference (MMI) (Walsh and Kaiser in Radiat Environ Biophys 50:21-35, 2011). The models use a linear-quadratic dose response with differing dose effect modifiers. In the present study, a set of more than 40 models has been submitted to a rigorous statistical selection procedure which fosters the parsimonious deployment of model parameters based on pairwise likelihood ratio tests. Nested models were consequently excluded from risk assessment. The set comprises models of the excess absolute risk (EAR) and two types of non-standard ERR models with sigmoidal responses or two line spline functions with a changing slope at a break point. Due to clearly higher values of the Akaike Information Criterion, none of the EAR models has been selected, but two non-standard ERR models qualified for MMI. The preferred ERR model applies a purely quadratic dose response which is slightly damped by an exponential factor at high doses and modified by a power function for attained age. Compared to the previous analysis, the present study reports similar point estimates and confidence intervals (CI) of the ERR from MMI for doses between 0.5 and 2.5 Sv. However, at lower doses, the point estimates are markedly reduced by factors between two and five, although the reduction was not statistically significant. The 2.5 % percentiles of the ERR from the preferred quadratic-exponential model did not fall below zero risk in exposure scenarios for children, adolescents and adults at very low doses down to 10 mSv. Yet, MMI produced risk estimates with a positive 2.5 % percentile only above doses of some 300 mSv. Compared to CI from a single model of choice, CI from MMI are broadened in cohort strata with low statistical power by a combination of risk extrapolations from several

  3. The parvocellular vasotocin system of Japanese quail: a developmental and adult model for the study of influences of gonadal hormones on sexually differentiated and behaviorally relevant neural circuits.

    PubMed Central

    Panzica, Gian Carlo; Bakthazart, Jacques; Pessatti, Marzia; Viglietti-Panzica, Carla

    2002-01-01

    Vasotocin (VT; the antidiuretic hormone of birds) is synthesized by diencephalic magnocellular neurons projecting to the neurohypophysis. A sexually dimorphic system of VT-immunoreactive (ir) parvocellular elements has been described within the male medial preoptic nucleus (POM) and the nucleus of the stria terminalis, pars medialis (BSTm). VT-ir fibers are present in many diencephalic and extradiencephalic locations, and quantitative morphometric analyses demonstrated their sexually dimorphic distribution in regions involved in the control of different aspects of reproduction. Moreover, systemic or intracerebroventricular injections of VT markedly inhibit the expression of some aspects of male sexual behavior. In adult animals, circulating levels of testosterone (T) have a profound influence on the VT immunoreactivity within BSTm, POM, and lateral septum. Castration markedly decreases the immunoreaction, whereas T-replacement therapy restores a situation similar to the intact birds. We observed no changes in gonadectomized females treated with T. These changes parallel similar changes in male copulatory behavior (not present in castrated male quail, fully expressed in castrated, T-treated males). The restoration by T of the VT immunoreactivity in castrated male quail could be fully mimicked by a treatment with estradiol (E(2)), suggesting that the aromatization of T into E(2) may play a key limiting role in both the activation of male sexual behavior and the induction of VT synthesis. This dimorphism has an organizational nature: administration of E(2) to quail embryos (a treatment that abolishes male sexual behavior) results in a dramatic decrease of the VT immunoreactivity in sexually dimorphic regions. Conversely, the inhibition of E(2) synthesis during embryonic life (a treatment that stimulates the expression of male copulatory behavior in treated females exposed in adulthood to T) results in a malelike distribution of VT immunoreactivity. The VT

  4. Multi-model inference of adult and childhood leukaemia excess relative risks based on the Japanese A-bomb survivors mortality data (1950-2000).

    PubMed

    Walsh, Linda; Kaiser, Jan Christian

    2011-03-01

    Some relatively new issues that augment the usual practice of ignoring model uncertainty, when making inference about parameters of a specific model, are brought to the attention of the radiation protection community here. Nine recently published leukaemia risk models, developed with the Japanese A-bomb epidemiological mortality data, have been included in a model-averaging procedure so that the main conclusions do not depend on just one type of model or statistical test. The models have been centred here at various adult and young ages at exposure, for some short times since exposure, in order to obtain specially computed childhood Excess Relative Risks (ERR) with uncertainties that account for correlations in the fitted parameters associated with the ERR dose-response. The model-averaged ERR at 1 Sv was not found to be statistically significant for attained ages of 7 and 12 years but was statistically significant for attained ages of 17, 22 and 55 years. Consequently, such risks when applied to other situations, such as children in the vicinity of nuclear installations or in estimates of the proportion of childhood leukaemia incidence attributable to background radiation (i.e. low doses for young ages and short times since exposure), are only of very limited value, with uncertainty ranges that include zero risk. For example, assuming a total radiation dose to a 5-year-old child of 10 mSv and applying the model-averaged risk at 10 mSv for a 7-year-old exposed at 2 years of age would result in an ERR=0.33, 95% CI: -0.51 to 1.22. One model (United Nations scientific committee on the effects of atomic radiation report. Volume 1. Annex A: epidemiological studies of radiation and cancer, United Nations, New York, 2006) weighted model-averaged risks of leukaemia most strongly by half of the total unity weighting and is recommended for application in future leukaemia risk assessments that continue to ignore model uncertainty. However, on the basis of the analysis

  5. Genetic control of startle behavior in medaka fish.

    PubMed

    Tsuboko, Satomi; Kimura, Tetsuaki; Shinya, Minori; Suehiro, Yuji; Okuyama, Teruhiro; Shimada, Atsuko; Takeda, Hiroyuki; Naruse, Kiyoshi; Kubo, Takeo; Takeuchi, Hideaki

    2014-01-01

    Genetic polymorphisms are thought to generate intraspecific behavioral diversities, both within and among populations. The mechanisms underlying genetic control of behavioral properties, however, remain unclear in wild-type vertebrates, including humans. To explore this issue, we used diverse inbred strains of medaka fish (Oryzias latipes) established from the same and different local populations. Medaka exhibit a startle response to a visual stimulus (extinction of illumination) by rapidly bending their bodies (C-start) 20-ms after the stimulus presentation. We measured the rates of the response to repeated stimuli (1-s interval, 40 times) among four inbred strains, HNI-I, HNI-II, HO5, and Hd-rR-II1, and quantified two properties of the startle response: sensitivity (response rate to the first stimulus) and attenuation of the response probability with repeated stimulus presentation. Among the four strains, the greatest differences in these properties were detected between HNI-II and Hd-rR-II1. HNI-II exhibited high sensitivity (approximately 80%) and no attenuation, while Hd-rR-II1 exhibited low sensitivity (approximately 50%) and almost complete attenuation after only five stimulus presentations. Our findings suggested behavioral diversity of the startle response within a local population as well as among different populations. Linkage analysis with F2 progeny between HNI-II and Hd-rR-II1 detected quantitative trait loci (QTL) highly related to attenuation, but not to sensitivity, with a maximum logarithm of odds score of 11.82 on linkage group 16. The three genotypes (homozygous for HNI-II and Hd-rR-II1 alleles, and heterozygous) at the marker nearest the QTL correlated with attenuation. Our findings are the first to suggest that a single genomic region might be sufficient to generate individual differences in startle behavior between wild-type strains. Further identification of genetic polymorphisms that define the behavioral trait will contribute to our

  6. Genetic Control of Startle Behavior in Medaka Fish

    PubMed Central

    Tsuboko, Satomi; Kimura, Tetsuaki; Shinya, Minori; Suehiro, Yuji; Okuyama, Teruhiro; Shimada, Atsuko; Takeda, Hiroyuki; Naruse, Kiyoshi; Kubo, Takeo; Takeuchi, Hideaki

    2014-01-01

    Genetic polymorphisms are thought to generate intraspecific behavioral diversities, both within and among populations. The mechanisms underlying genetic control of behavioral properties, however, remain unclear in wild-type vertebrates, including humans. To explore this issue, we used diverse inbred strains of medaka fish (Oryzias latipes) established from the same and different local populations. Medaka exhibit a startle response to a visual stimulus (extinction of illumination) by rapidly bending their bodies (C-start) 20-ms after the stimulus presentation. We measured the rates of the response to repeated stimuli (1-s interval, 40 times) among four inbred strains, HNI-I, HNI-II, HO5, and Hd-rR-II1, and quantified two properties of the startle response: sensitivity (response rate to the first stimulus) and attenuation of the response probability with repeated stimulus presentation. Among the four strains, the greatest differences in these properties were detected between HNI-II and Hd-rR-II1. HNI-II exhibited high sensitivity (approximately 80%) and no attenuation, while Hd-rR-II1 exhibited low sensitivity (approximately 50%) and almost complete attenuation after only five stimulus presentations. Our findings suggested behavioral diversity of the startle response within a local population as well as among different populations. Linkage analysis with F2 progeny between HNI-II and Hd-rR-II1 detected quantitative trait loci (QTL) highly related to attenuation, but not to sensitivity, with a maximum logarithm of odds score of 11.82 on linkage group 16. The three genotypes (homozygous for HNI-II and Hd-rR-II1 alleles, and heterozygous) at the marker nearest the QTL correlated with attenuation. Our findings are the first to suggest that a single genomic region might be sufficient to generate individual differences in startle behavior between wild-type strains. Further identification of genetic polymorphisms that define the behavioral trait will contribute to our

  7. Persistent endocrine disruption effects in medaka fish with early life-stage exposure to a triazole-containing aromatase inhibitor (letrozole).

    PubMed

    Liao, Pei-Han; Chu, Szu-Hung; Tu, Tzu-Yi; Wang, Xiao-Huan; Lin, Angela Yu-Chen; Chen, Pei-Jen

    2014-07-30

    Letrozole (LET) is a triazole-containing drug that can inhibit the activity of cytochrome P450 aromatase. It is an environmentally emerging pollutant because of its broad use in medicine and frequent occurrence in aquifers receiving the effluent of municipal or hospital wastewater. However, the toxic impact of LET on fish populations remains unclear. We exposed medaka fish (Oryzias latipes) at an early stage of sexual development to a continuous chronic LET at environmentally relevant concentrations and assessed the endocrine disruption effects in adulthood and the next generation. LET exposure at an early life stage persistently altered phenotypic sex development and reproduction in adults and skewed the sex ratio in progeny. As well, LET exposure led to a gender-different endocrine disruption as seen by the interruption in gene expression responsible for estrogen synthesis and metabolism and fish reproduction. LET interfering with the aromatase system in early life stages of medaka can disrupt hormone homeostasis and reproduction. This potent aromatase inhibitor has potential ecotoxicological impact on fish populations in aquatic environments. PMID:24613401

  8. 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. PMID:21252980

  9. Sexual dimorphism of brain aromatase activity in medaka: induction of a female phenotype by estradiol.

    PubMed Central

    Melo, A C; Ramsdell, J S

    2001-01-01

    In this study we identified sex-dependent dimorphism of brain aromatase in the teleost medaka and examined its regulation by sex steriods. We first investigated differential distribution of brain aromatase activity in sexually mature male and female medaka in serial coronal sections of the brain and identified the hypothalamic nuclei contained in each section using the brain atlas of medaka. In the brain of male medaka, high levels of activity are localized in sections containing the preoptic (POA) and suprachiasmatic nuclei (SC) (63-75 fmol/hr) and low levels in the nuclei periventricular dorsalis (HD), ventralis (HV), and caudalis (Hc), nuclei diffusus of lobulus inferiores (NDIL), and nuclei tuberi anteriores (TA) and posteriores (TP) (< 25 fmol/hr). In the brain of female medaka high aromatase activity is localized in sections containing the HD, HV, Hc, NDIL, TA, and TP (85-80 fmol/hr) and highly variable levels in the POA and SC (23-70 fmol/hr). The concentration and time dependency of the exposure of male medaka to estradiol on the total brain aromatase activity and morphologic sex characteristics were determined next. Estradiol increased the activity of brain aromatase in a concentration-dependent manner at 2.5 and 25 microg/L, but the increase was lower at higher concentrations of the hormone. The effect was time dependent, gradually increasing up to the fifth day of exposure, after which it reached a plateau. Estradiol induction of brain aromatase analyzed using Lineweaver-Burke plots of saturation assays revealed a non-first-order reaction. The results indicate that a positive feedback mechanism regulates brain aromatase and imply that the sexual dimorphic distribution of aromatase may be highly sensitive to physiologic cues and environmental perturbations in fish. PMID:11333187

  10. Vocational Behavior of the Japanese in Late Adulthood: Focusing on Those in the Retirement Process.

    ERIC Educational Resources Information Center

    Watanabe-Muraoka, A. Mieko; Kawasaki, Tomotsugu; Sato, Shin'ichi

    1998-01-01

    Having experienced traditional Japanese employment system, older Japanese adults are affected by workplace and socioeconomic changes. Two recent surveys of workers nearing retirement showed high work salience and considerable anxiety about retirement. (SK)

  11. Transcriptomic responses of marine medaka's ovary to hypoxia.

    PubMed

    Lai, Keng Po; Li, Jing Woei; Tse, Anna Chung Kwan; Cheung, Angela; Wang, Simon; Chan, Ting Fung; Kong, Richard Yuen Chong; Wu, Rudolf Shiu Sun

    2016-08-01

    Hypoxia, an endocrine disruptor, is pressing global problem affecting marine organisms in over 400 "Dead Zones" worldwide. There is growing evident demonstrated the disruptive effect of hypoxia on reproductive systems of marine fish through the impairments of steroidogenic gene expression, leading to the alteration of sex hormone production in gonads. But the detailed molecular mechanism underlying the responses of female reproductive systems to hypoxic stress remains largely unknown. In the present report, we used marine medaka Oryzias melastigma as a model, together with high-throughput transcriptome sequencing and bioinformatics analysis, aiming to determine the changes in transcriptional signature in the ovary of marine fish under hypoxic stress. Our result discovered over two hundred differential expressed genes in ovary in response to hypoxia. The bioinformatics analysis together with quantitative RT-PCR validation on the deregulated genes highlighted the dysregulations of a number of female reproductive functions including interruptions of ovarian follicle development, gonad development and steroid metabolic process. Additionally, we revealed that these deregulations are through the modulation of leukemia inhibitory factor (LIF), insulin-like growth factor 1 receptor (IGF1R) and follicle stimulating hormone (FSH). The result of this work complements previous studies and provides additional insights into the underlying molecular mechanism of hypoxia-induced impairment of female reproductive system. PMID:27423118

  12. Turnover of Sex Chromosomes in Celebensis Group Medaka Fishes.

    PubMed

    Myosho, Taijun; Takehana, Yusuke; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

    2015-12-01

    Sex chromosomes and the sex-determining (SD) gene are variable in vertebrates. In particular, medaka fishes in the genus Oryzias show an extremely large diversity in sex chromosomes and the SD gene, providing a good model to study the evolutionary process by which they turnover. Here, we investigated the sex determination system and sex chromosomes in six celebensis group species. Our sex-linkage analysis demonstrated that all species had an XX-XY sex determination system, and that the Oryzias marmoratus and O. profundicola sex chromosomes were homologous to O. latipes linkage group (LG) 10, while those of the other four species, O. celebensis, O. matanensis, O. wolasi, and O. woworae, were homologous to O. latipes LG 24. The phylogenetic relationship suggested a turnover of the sex chromosomes from O. latipes LG 24 to LG 10 within this group. Six sex-linkage maps showed that the former two and the latter four species shared a common SD locus, respectively, suggesting that the LG 24 acquired the SD function in a common ancestor of the celebensis group, and that the LG 10 SD function appeared in a common ancestor of O. marmoratus and O. profundicola after the divergence of O. matanensis. Additionally, fine mapping and association analysis in the former two species revealed that Sox3 on the Y chromosome is a prime candidate for the SD gene, and that the Y-specific 430-bp insertion might be involved in its SD function. PMID:26497145

  13. The Acquisitional Value of Recasts in Instructed Second Language Speech Learning: Teaching the Perception and Production of English /?/ to Adult Japanese Learners

    ERIC Educational Resources Information Center

    Saito, Kazuya

    2013-01-01

    The current study investigated the impact of recasts together with form-focused instruction (FFI) on the development of second language speech perception and production of English /?/ by Japanese learners. Forty-five learners were randomly assigned to three groups--FFI recasts, FFI only, and Control--and exposed to four hours of communicatively…

  14. Handling Japanese without a Japanese Operating System.

    ERIC Educational Resources Information Center

    Hatasa, Kazumi; And Others

    1992-01-01

    The Macintosh HyperCard environment has become a popular platform for Japanese language courseware because of its flexibility and ease of programing. This project created Japanese bitmap font files for the JIS Levels 1 and 2, and writing XFCNs for font manipulation, Japanese kana input, and answer correction. (12 references) (Author/LB)

  15. Japanese encephalitis.

    PubMed

    Morita, K; Nabeshima, T; Buerano, C C

    2015-08-01

    Japanese encephalitis (JE) is an inflammation of the central nervous system in humans and animals, specifically horses and cattle. The disease, which can sometimes be fatal, is caused by the flavivirus Japanese encephalitis virus (JEV), of which there are five genotypes (genotypes 1, 2, 3, 4 and 5). The transmission cycle of the virus involves pigs and wild birds as virus amplifiers and mosquitoes as vectors for transferring the virus between amplifying hosts and to dead- end hosts, i.e. humans, horses and cattle. In horses and cattle the disease is usually asymptomatic, but when clinical signs do occur they include fever, decreased appetite, frothing at the mouth, rigidity of the legs and recumbency, and neurological signs, such as convulsive fits, circling, marked depression and disordered consciousness. In pigs, it can cause abortion and stillbirths. At present, the virus is detected in a wide area covering eastern and southern Asia, Indonesia, northern Australia, Papua New Guinea and Pakistan. JEV RNA has also been detected in Italy, first in dead birds in 1997 and 2000 and then in mosquitoes in 2010. Genotype shift, i.e. a change of genotype from genotype 3 to genotype 1, has occurred in some countries, namely Japan, South Korea, Chinese Taipei and Vietnam. Laboratory methods are available for confirming the causative agent of the disease. There are control measures to prevent or minimise infection and, among them, vaccination is one of the most important and one which should be adopted in endemic and epidemic areas. PMID:26601447

  16. Japanese encephalitis

    PubMed Central

    Yun, Sang-Im; Lee, Young-Min

    2014-01-01

    Japanese encephalitis (JE) is an infectious disease of the central nervous system caused by Japanese encephalitis virus (JEV), a zoonotic mosquito-borne flavivirus. JEV is prevalent in much of Asia and the Western Pacific, with over 4 billion people living at risk of infection. In the absence of antiviral intervention, vaccination is the only strategy to develop long-term sustainable protection against JEV infection. Over the past half-century, a mouse brain-derived inactivated vaccine has been used internationally for active immunization. To date, however, JEV is still a clinically important, emerging, and re-emerging human pathogen of global significance. In recent years, production of the mouse brain-derived vaccine has been discontinued, but 3 new cell culture-derived vaccines are available in various parts of the world. Here we review current aspects of JEV biology, summarize the 4 types of JEV vaccine, and discuss the potential of an infectious JEV cDNA technology for future vaccine development. PMID:24161909

  17. TOXICOKINETICS AND METABOLISM OF ANILINE AND 4-CHLORANILINE IN MEDAKA (ORYZIAS LATIPES)

    EPA Science Inventory

    The in vivo toxicokinetics and in vitro hepatic microsomal metabolism of [14C]aniline and [14C]4-chloraniline in medaka (Oryzias latipes) were investigated to provide a basis upon which to interpret the toxicological responses of small aquarium fish to aniline derivatives. uring ...

  18. Effects of Di-butyl Phthalate (DBP) on Developing Medaka Embryos

    ERIC Educational Resources Information Center

    Tang, Sherry

    2012-01-01

    Plasticizers are chemical additives that enhance plastic flexibility. They are ubiquitous environmental contaminants and are commonly found in river and lake waters (Fromme et al 2002). The present study aimed to investigate the effects of a water-soluble plasticizer, dibutyl phthalate (DBP) on developing Medaka ("Oryzias latipes") embryos. Three…

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

    EPA Science Inventory

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

  20. 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. PMID:27002527

  1. 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.

  2. Gonadotrophic cells and gonadal sex differentiation in medaka: Characterization of several northern and southern strains.

    PubMed

    Horie, Yoshifumi; Kobayashi, Tohru

    2015-07-01

    Gonadotropins play an important role in gametogenesis and reproduction in vertebrates. Their localization in the pituitary during gonadal sex differentiation has been studied mainly in southern (Oryzias latipes) strains of medaka fish, with that in northern medaka (O. sakaizumii) remaining poorly understood. Hence, in this study, we characterized gonadal differentiation and gonadotrophic cells during sex differentiation in two northern strains (HNI and Kaga) and two southern strains (Hd-rR and d-rR/Tokyo). All strains exhibited similar sex differentiation at hatching, such as (1) sex difference in germ cell number (XX > XY), and (2) the transition of XX germ cells into meiosis, and (3) presence of glycoprotein-α (Gpa)-positive cells. However, follicle-stimulating hormone-β (Fshb)-positive cells were first detected in the pituitary 1 day post-hatching in HNI. Exposure to high-temperature conditions and to cortisol in a dose dependent manner resulted in the localization of Fshb cells in the pituitary at hatching. This study demonstrates differences in gonadotropin subunit expression between northern and southern strains of medaka, and suggests that Fsh is not involved in early gonadal sex differentiation, such as the sex difference in germ cell number, and that high-temperature induce Fshb expression via cortisol production in medaka. PMID:25866156

  3. MX, A DRINKING WATER CARCINOGEN, DOES NOT INDUCE MUTATIONS IN THE LIVER OF CII TRANSGENIC MEDAKA

    EPA Science Inventory

    MX, a drinking water carcinogen, does not induce mutations in the liver of cII transgenic medaka
    Geter, DR; Winn, RN; Fournie, JW; Norris, MB; DeAngelo, AB; and Hawkins, WE

    Abstract

    Geter et al., page 2
    Abstract
    "Salmonella" mutagenicity assays have shown t...

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

    PubMed Central

    Colman, Jamie R; Ramsdell, John S

    2003-01-01

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

  5. 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).

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

    PubMed Central

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

    2009-01-01

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

  7. Estradiol-induced promotion of hepatocarcinogenesis in medaka: Relationship of foci of cellular alteration to neoplasia

    SciTech Connect

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

    1995-12-31

    In some laboratory and field studies, female fish have higher prevalences of liver tumors than do males. The authors hypothesize gender and site-specific differences in prevalence are due to variable exposures of previously initiated fish to tumor modulating compounds. Estradiol, a growth promoter, increases incidences of hepatic tumors in carcinogen-treated rainbow trout and medaka (Oryzias latipes). Estradiol also increases incidences of hepatic foci of cellular alteration (FCA) in medaka. FCA are found in subadults of tumor-bearing feral populations. Lack of knowledge about the relationship of various phenotypes of FCA to eventual tumors, however, has prevented use of FCA as a biomarker. The authors examined fate and growth of liver FCA using a 2-step, initiation-promotion protocol. Three week old medaka were exposed to 200 ppm diethylnitrosamine (DEN) for 24 hr. and then fed 0.1 ppm 17-{beta}-estradiol (E2) continuously through sampling at weeks 4--26. Percent volume of FCA and morphometric characteristics of normal and focal hepatocytes, including numerical density and average hepatocyte volume were quantified using computer-assisted stereology. E2 increased percentage of liver occupied by DEN-initiated amphophilic, basophilic and eosinophilic FCA in both sexes. Focal parameters of young, DEN-initiated and estradiol-treated medaka were not reached until much later in fish given only DEN. Non-focal hepatocytes in estradiol-treated medaka were smaller and more numerous than in DEN-only counterparts. Morphometric analysis is quantitatively tracking the fate of specific phenotypes of FCA to determine their role in progression to cancer.

  8. A medaka model of cancer allowing direct observation of transplanted tumor cells in vivo at a cellular-level resolution.

    PubMed

    Hasegawa, Sumitaka; Maruyama, Kouichi; Takenaka, Hikaru; Furukawa, Takako; Saga, Tsuneo

    2009-08-18

    The recent success with small fish as an animal model of cancer with the aid of fluorescence technique has attracted cancer modelers' attention because it would be possible to directly visualize tumor cells in vivo in real time. Here, we report a medaka model capable of allowing the observation of various cell behaviors of transplanted tumor cells, such as cell proliferation and metastasis, which were visualized easily in vivo. We established medaka melanoma (MM) cells stably expressing GFP and transplanted them into nonirradiated and irradiated medaka. The tumor cells were grown at the injection sites in medaka, and the spatiotemporal changes were visualized under a fluorescence stereoscopic microscope at a cellular-level resolution, and even at a single-cell level. Tumor dormancy and metastasis were also observed. Interestingly, in irradiated medaka, accelerated tumor growth and metastasis of the transplanted tumor cells were directly visualized. Our medaka model provides an opportunity to visualize in vivo tumor cells "as seen in a culture dish" and would be useful for in vivo tumor cell biology. PMID:19666513

  9. A medaka model of cancer allowing direct observation of transplanted tumor cells in vivo at a cellular-level resolution

    PubMed Central

    Hasegawa, Sumitaka; Maruyama, Kouichi; Takenaka, Hikaru; Furukawa, Takako; Saga, Tsuneo

    2009-01-01

    The recent success with small fish as an animal model of cancer with the aid of fluorescence technique has attracted cancer modelers' attention because it would be possible to directly visualize tumor cells in vivo in real time. Here, we report a medaka model capable of allowing the observation of various cell behaviors of transplanted tumor cells, such as cell proliferation and metastasis, which were visualized easily in vivo. We established medaka melanoma (MM) cells stably expressing GFP and transplanted them into nonirradiated and irradiated medaka. The tumor cells were grown at the injection sites in medaka, and the spatiotemporal changes were visualized under a fluorescence stereoscopic microscope at a cellular-level resolution, and even at a single-cell level. Tumor dormancy and metastasis were also observed. Interestingly, in irradiated medaka, accelerated tumor growth and metastasis of the transplanted tumor cells were directly visualized. Our medaka model provides an opportunity to visualize in vivo tumor cells “as seen in a culture dish” and would be useful for in vivo tumor cell biology. PMID:19666513

  10. QT/QTc study conducted in Japanese adult healthy subjects: a novel xanthine oxidase inhibitor topiroxostat was not associated with QT prolongation.

    PubMed

    Sugiyama, Atsushi; Hashimoto, Hiroya; Nakamura, Yuji; Fujita, Tomoe; Kumagai, Yuji

    2014-04-01

    A QT/QTc study was conducted in compliance with ICH E14 guideline to evaluate the effects of a new xanthine oxidase inhibitor topiroxostat in Japanese healthy subjects. Forty-eight Japanese healthy subjects (males 24; females 24) received a single oral dose of topiroxostat (60 or 180 mg), moxifloxacin (400 mg) or placebo in a single-center, double-blind, four-period crossover design. Fridericia's formula (QTcF = QT/RR(0.33) ) was used as a primary method for QT-interval correction. The mean QTcF was prolonged by moxifloxacin, of which largest time-matched difference from placebo administration was 13.6 milliseconds with 90% confidence interval (CI) of 11.2 and 15.9 milliseconds at 4 hours post-dose. The mean QTcF was hardly affected by either dose of topiroxostat, of which largest time-matched difference from placebo administration was 2.9 milliseconds with 90% CI of 0.6 and 5.3 milliseconds at 4 hours post-dose for 60 mg, and 2.3 milliseconds with 90% CI of 0 and 4.7 milliseconds at 1 hour post-dose for 180 mg. The results were essentially the same in the sex subgroup analysis. Moxifloxacin can be used as a positive control for QT/QTc studies in Japanese subjects; and topiroxostat may not cause QT-interval prolongation in males as well as females. PMID:24214189

  11. Development of the Gerotranscendence Scale Type 2: Japanese Version

    ERIC Educational Resources Information Center

    Hoshino, Kazumi; Zarit, Steven H.; Nakayama, Makoto

    2012-01-01

    This study developed the Japanese version of the Gerotranscendence Scale Type 2 (the GST2) and examined reliability and validity of the scale. In Japan, 525 community-dwelling older adults (Male = 260, Female = 265) answered a questionnaire. An exploratory factor analysis of the Japanese version of the GST2 revealed the same three-factor structure…

  12. The Internalization of Values: Adopting Cooperation (Sunao) in Japanese Preschools.

    ERIC Educational Resources Information Center

    Taylor, Satomi Izumi; And Others

    Japanese children are socialized to internalize parental, group, and institutional norms. Japanese adults believe "good" children to be sunao (cooperative). Sunao is difficult to translate into English, but can be thought of as being gentle and spirited. This paper presents a study that examined and described feelings and thoughts of Japanese…

  13. Ethnocentrism, Cultural Traits, Beliefs, and English Proficiency: A Japanese Sample.

    ERIC Educational Resources Information Center

    Hinenoya, Kimiko; Gatbonton, Elizabeth

    2000-01-01

    Investigated the role in second language (L2) learning of ethnocentrism, cultural and personality traits, and acceptance of values and beliefs expressed in myths and proverbs. Japanese adults (n-108) living in North American were asked how much they agreed with or accepted statements expressing ethnocentric views about Japanese culture and…

  14. Effects of New Dietary Fiber from Japanese Apricot (Prunus mume Sieb. et Zucc.) on Gut Function and Intestinal Microflora in Adult Mice

    PubMed Central

    Tamura, Motoi; Ohnishi, Yuriko; Kotani, Tatsuya; Gato, Nobuki

    2011-01-01

    Much attention has been focused recently on functional foods. Ume, the Japanese name for the apricot of Prunus mume Sieb. et Zucc., is an example of a Japanese traditional functional food. There are, however, few reports on the effects of fiber from this fruit on bowel function. With this objective, we prepared ume fiber to test the hypothesis that it can change gut function and intestinal flora in mice. Mice were fed an ume fiber (UF) or cellulose (CF) diet (control) for 40 days. The fecal weight, fecal lipids, plasma lipids and cecal composition of the microflora were analyzed. The amount of feces was significantly greater in the UF group than in the CF group (p < 0.01). The fecal lipids content (% DW) of the feces sampled on the final day of the experiment were significantly greater in the UF group than in the CF group (p < 0.01). Plasma non-esterified fatty acids (NEFA) concentrations tended to be lower in the UF compared to the CF group (p = 0.058). Occupation ratios of Bacteroides and Clostridium cluster IV were significantly greater in the cecal flora of the UF group. Our results suggest that ume fiber possesses the fecal lipid excretion effects and feces bulking effects. PMID:21731428

  15. Effects of new dietary fiber from Japanese Apricot (Prunus mume Sieb. et Zucc.) on gut function and intestinal microflora in adult mice.

    PubMed

    Tamura, Motoi; Ohnishi, Yuriko; Kotani, Tatsuya; Gato, Nobuki

    2011-01-01

    Much attention has been focused recently on functional foods. Ume, the Japanese name for the apricot of Prunus mume Sieb. et Zucc., is an example of a Japanese traditional functional food. There are, however, few reports on the effects of fiber from this fruit on bowel function. With this objective, we prepared ume fiber to test the hypothesis that it can change gut function and intestinal flora in mice. Mice were fed an ume fiber (UF) or cellulose (CF) diet (control) for 40 days. The fecal weight, fecal lipids, plasma lipids and cecal composition of the microflora were analyzed. The amount of feces was significantly greater in the UF group than in the CF group (p < 0.01). The fecal lipids content (% DW) of the feces sampled on the final day of the experiment were significantly greater in the UF group than in the CF group (p < 0.01). Plasma non-esterified fatty acids (NEFA) concentrations tended to be lower in the UF compared to the CF group (p = 0.058). Occupation ratios of Bacteroides and Clostridium cluster IV were significantly greater in the cecal flora of the UF group. Our results suggest that ume fiber possesses the fecal lipid excretion effects and feces bulking effects. PMID:21731428

  16. Identified lhb-expressing cells from medaka (Oryzias latipes) show similar Ca(2+)-response to all endogenous Gnrh forms, and reveal expression of a novel fourth Gnrh receptor.

    PubMed

    Strandabø, Rønnaug A U; Grønlien, Heidi K; Ager-Wick, Eirill; Nourizadeh-Lillabadi, Rasoul; Hildahl, Jon P; Weltzien, Finn-Arne; Haug, Trude M

    2016-04-01

    We have previously characterized the response to gonadotropin-releasing hormone (Gnrh) 2 in luteinizing hormone (lhb)-expressing cells from green fluorescent protein (Gfp)-transgenic medaka (Oryzias latipes), with regard to changes in the cytosolic Ca(2+) concentration. In the current study we present the corresponding responses to Gnrh1 and Gnrh3. Ca(2+) imaging revealed three response patterns to Gnrh1 and Gnrh3, one monophasic and two types of biphasic patterns. There were few significant differences in the shape of the response patterns between the three Gnrh forms, although the amplitude of the Ca(2+) signal was considerably lower for Gnrh1 and Gnrh3 than for Gnrh2, and the distribution between the two different biphasic patterns differed. The different putative Ca(2+) sources were examined by depleting intracellular Ca(2+) stores with thapsigargin, or preventing influx of extracellular Ca(2+) by either extracellular Ca(2+) depletion or the L-type Ca(2+)-channel blocker verapamil. Both Gnrh1 and 3 relied on Ca(2+) from both intracellular and extracellular sources, with some unexpected differences in the relative contribution. Furthermore, gene expression of Gnrh-receptors (gnrhr) in whole pituitaries was studied during development from juvenile to adult. Only two of the four identified medaka receptors were expressed in the pituitary, gnrhr1b and gnrhr2a, with the newly discovered gnrhr2a showing the highest expression level at all stages as analyzed by quantitative PCR. While both receptors differed in expression level according to developmental stage, only the expression of gnrhr2a showed a clear-cut increase with gonadal maturation. RNA sequencing analysis of FACS-sorted Gfp-positive lhb-cells revealed that both gnrhr1b and gnrhr2a were expressed in lhb-expressing cells, and confirmed the higher expression of gnrhr2a compared to gnrhr1b. These results show that although lhb-expressing gonadotropes in medaka show similar Ca(2+) response patterns to all three

  17. Reinspiring Japanese Educational Objectives.

    ERIC Educational Resources Information Center

    Wada, Shuji

    1993-01-01

    Provides a brief overview of the history of modern Japanese education, its early modernization, and the policy of intertwining the Japanese ideology with Western technology. Proposes the establishment of a new Buddhist-inspired philosophy of education. (GLR)

  18. The Japanese Mind: Understanding Contemporary Japanese Culture.

    ERIC Educational Resources Information Center

    Davies, Roger J., Ed.; Ikeno, Osamu, Ed.

    This collection of essays offers an overview of contemporary Japanese culture, and can serve as a resource for classes studying Japan. The 28 essays offer an informative, accessible look at the values, attitudes, behavior patterns, and communication styles of modern Japan from the unique perspective of the Japanese people. Filled with examples…

  19. Bullying in Japanese Schools.

    ERIC Educational Resources Information Center

    Kobayashi, Futoshi

    Noting that although many Western educators praise the Japanese educational system because of its students' academic achievements, schools in Japan have developed severe and prevalent problems with student bullying. This paper examines the problem of bullying in Japanese schools. Part 1 of the paper reviews bullying incidents in Japanese schools…

  20. Japanese Radio Exercises. Revised.

    ERIC Educational Resources Information Center

    Young, Jocelyn

    This unit focuses on Japanese radio exercises which became popular in Japan just after World War II and are still used among students and workers in companies to help raise morale and form group unity. The exercises reflect the general role of exercise in Japanese culture--to serve as a symbol of unity and cooperation among the Japanese, as well…

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

    EPA Science Inventory

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

  2. 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, ...

  3. Microgravity promotes osteoclast activity in medaka fish reared at the international space station.

    PubMed

    Chatani, Masahiro; Mantoku, Akiko; Takeyama, Kazuhiro; Abduweli, Dawud; Sugamori, Yasutaka; Aoki, Kazuhiro; Ohya, Keiichi; Suzuki, Hiromi; Uchida, Satoko; Sakimura, Toru; Kono, Yasushi; Tanigaki, Fumiaki; Shirakawa, Masaki; Takano, Yoshiro; Kudo, Akira

    2015-01-01

    The bone mineral density (BMD) of astronauts decreases specifically in the weight-bearing sites during spaceflight. It seems that osteoclasts would be affected by a change in gravity; however, the molecular mechanism involved remains unclear. Here, we show that the mineral density of the pharyngeal bone and teeth region of TRAP-GFP/Osterix-DsRed double transgenic medaka fish was decreased and that osteoclasts were activated when the fish were reared for 56 days at the international space station. In addition, electron microscopy observation revealed a low degree of roundness of mitochondria in osteoclasts. In the whole transcriptome analysis, fkbp5 and ddit4 genes were strongly up-regulated in the flight group. The fish were filmed for abnormal behavior; and, interestingly, the medaka tended to become motionless in the late stage of exposure. These results reveal impaired physiological function with a change in mechanical force under microgravity, which impairment was accompanied by osteoclast activation. PMID:26387549

  4. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish.

    PubMed

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-03-01

    Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. PMID:26852942

  5. Microgravity promotes osteoclast activity in medaka fish reared at the international space station

    PubMed Central

    Chatani, Masahiro; Mantoku, Akiko; Takeyama, Kazuhiro; Abduweli, Dawud; Sugamori, Yasutaka; Aoki, Kazuhiro; Ohya, Keiichi; Suzuki, Hiromi; Uchida, Satoko; Sakimura, Toru; Kono, Yasushi; Tanigaki, Fumiaki; Shirakawa, Masaki; Takano, Yoshiro; Kudo, Akira

    2015-01-01

    The bone mineral density (BMD) of astronauts decreases specifically in the weight-bearing sites during spaceflight. It seems that osteoclasts would be affected by a change in gravity; however, the molecular mechanism involved remains unclear. Here, we show that the mineral density of the pharyngeal bone and teeth region of TRAP-GFP/Osterix-DsRed double transgenic medaka fish was decreased and that osteoclasts were activated when the fish were reared for 56 days at the international space station. In addition, electron microscopy observation revealed a low degree of roundness of mitochondria in osteoclasts. In the whole transcriptome analysis, fkbp5 and ddit4 genes were strongly up-regulated in the flight group. The fish were filmed for abnormal behavior; and, interestingly, the medaka tended to become motionless in the late stage of exposure. These results reveal impaired physiological function with a change in mechanical force under microgravity, which impairment was accompanied by osteoclast activation. PMID:26387549

  6. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish

    PubMed Central

    Hong, Ni; Li, Mingyou; Yuan, Yongming; Wang, Tiansu; Yi, Meisheng; Xu, Hongyan; Zeng, Huaqiang; Song, Jianxing; Hong, Yunhan

    2016-01-01

    Summary Primordial germ cell (PGC) specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes). Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model. PMID:26852942

  7. Different Modulatory Mechanisms of Renal FXYD12 for Na+-K+-ATPase between Two Closely Related Medakas upon Salinity Challenge

    PubMed Central

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

    2016-01-01

    Upon salinity challenge, the Na+-K+-ATPase (NKA) of fish kidney plays a crucial role in maintaining ion and water balance. Moreover, the FXYD protein family was found to be a regulator of NKA. Our preliminary results revealed that fxyd12 was highly expressed in the kidneys of the two closely related euryhaline medaka species (Oryzias dancena and O. latipes) from different natural habitats (brackish water and fresh water). In this study, we investigated the expression and association of renal FXYD12 and NKA α-subunit as well as potential functions of FXYD12 in the two medakas. These findings illustrated and compared the regulatory roles of FXYD12 for NKA in kidneys of the two medakas in response to salinity changes. In this study, at the mRNA and/or protein level, the expression patterns were similar for renal FXYD12 and NKA in the two medakas. However, different patterns of NKA activities and different interaction levels between FXYD12 and NKA were found in the kidneys of these two medakas. The results revealed that different strategies were used in the kidneys of the two medaka species upon salinity challenge. On the other hand, gene knockdown experiments demonstrated that the function of O. dancena FXYD12 allowed maintenance of a high level of NKA activity. The results of the present study indicated that the kidneys of the examined euryhaline medakas originating from brackish water and fresh water exhibited different modulatory mechanisms through which renal FXYD12 enhanced NKA activity to maintain internal homeostasis. Our findings broadened the knowledge of expression and functions of FXYD proteins, the modulators of NKA, in vertebrates. PMID:27194950

  8. Different Modulatory Mechanisms of Renal FXYD12 for Na(+)-K(+)-ATPase between Two Closely Related Medakas upon Salinity Challenge.

    PubMed

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

    2016-01-01

    Upon salinity challenge, the Na(+)-K(+)-ATPase (NKA) of fish kidney plays a crucial role in maintaining ion and water balance. Moreover, the FXYD protein family was found to be a regulator of NKA. Our preliminary results revealed that fxyd12 was highly expressed in the kidneys of the two closely related euryhaline medaka species (Oryzias dancena and O. latipes) from different natural habitats (brackish water and fresh water). In this study, we investigated the expression and association of renal FXYD12 and NKA α-subunit as well as potential functions of FXYD12 in the two medakas. These findings illustrated and compared the regulatory roles of FXYD12 for NKA in kidneys of the two medakas in response to salinity changes. In this study, at the mRNA and/or protein level, the expression patterns were similar for renal FXYD12 and NKA in the two medakas. However, different patterns of NKA activities and different interaction levels between FXYD12 and NKA were found in the kidneys of these two medakas. The results revealed that different strategies were used in the kidneys of the two medaka species upon salinity challenge. On the other hand, gene knockdown experiments demonstrated that the function of O. dancena FXYD12 allowed maintenance of a high level of NKA activity. The results of the present study indicated that the kidneys of the examined euryhaline medakas originating from brackish water and fresh water exhibited different modulatory mechanisms through which renal FXYD12 enhanced NKA activity to maintain internal homeostasis. Our findings broadened the knowledge of expression and functions of FXYD proteins, the modulators of NKA, in vertebrates. PMID:27194950

  9. Multicentre, randomised, placebo-controlled trial of extract of Japanese herbal medicine Daikenchuto to prevent bowel dysfunction after adult liver transplantation (DKB 14 Study)

    PubMed Central

    Kaido, Toshimi; Shimamura, Tsuyoshi; Sugawara, Yasuhiko; Sadamori, Hiroshi; Shirabe, Ken; Yamamoto, Michio; Uemoto, Shinji

    2015-01-01

    Introduction This multicentre randomised controlled clinical trial will aim to determine the ability of an extract (TJ-100) of Daikenchuto (traditional Japanese herbal medicine; Kampo) to prevent bowel dysfunction in at least 110 patients after liver transplantation (LT). Methods and analysis The following co-primary end points will be evaluated on postoperative day 7: total oral and enteral caloric intake, abdominal distension and abdominal pain. The secondary end points will comprise sequential changes of total oral and enteral caloric intake after LT, sequential changes in numeric rating scales for abdominal distension and pain, elapsed time to the first postoperative passage of stool, quality of life assessment using the Gastrointestinal Symptom Rating Scale score (Japanese version), postoperative liver function, liver regeneration rate, incidence of bacteraemia and bacterial strain, trough level of immunosuppressants, occurrence of acute cellular rejection, discharge or not within 2 months after LT, sequential changes of portal venous flow to the graft and ascites discharge. The two arms of the study will comprise 55 patients per arm. Ethics and dissemination The study has been conducted according to the CONSORT statement. All participants signed a written consent form, and the study has been approved by the institutional review board of each participating institute and conducted in accordance with the Declaration of Helsinki of 1996. The findings will be disseminated through scientific and professional conferences, and in peer-reviewed journals. Trial registration number The DKB 14 Study was registered in the University Hospital Medical Information Network Clinical Trial Registration (UMIN-CTR), Japan (registration number: UMIN000014326) during 2014. PMID:26419681

  10. Endocrine Disruption throughout the Hypothalamus-Pituitary-Gonadal-Liver (HPGL) Axis in Marine Medaka (Oryzias melastigma) Chronically Exposed to the Antifouling and Chemopreventive Agent, 3,3'-Diindolylmethane (DIM).

    PubMed

    Chen, Lianguo; Ye, Rui; Zhang, Weipeng; Hu, Chenyan; Zhou, Bingsheng; Peterson, Drew R; Au, Doris W T; Lam, Paul K S; Qian, Pei-Yuan

    2016-06-20

    Despite being proposed as a promising antifouling and chemopreventive agent, the environmental risks of 3,3'-diindolylmethane (DIM) are scarcely investigated. Therefore, this study used adult marine medaka (Oryzias melastigma) as a model organism to examine the toxicological effects and underlying mechanism of DIM throughout the hypothalamus-pituitary-gonadal-liver (HPGL) axis following 28 days of exposure to low DIM concentrations (0 and 8.46 μg/L). The results showed that altered gene transcription in the hypothalamus, pituitary, and gonads contributed to the great imbalance in hormone homeostasis. The lowered estradiol (E2)/testosterone (T) and E2/11-keto-testosterone (11-KT) ratios in female plasma resulted in decreased synthesis and levels of vitellogenin (VTG) and choriogenin in the liver and plasma, and vice versa in males. Subsequently, VTG and choriogenin deficiency blocked the reproductive function of the ovary as indicated by decreased fecundity and offspring viability, whereas in male medaka, DIM mainly targeted the liver and induced severe vacuolization. Proteomic profiling of plasma revealed that the sex-specific susceptibility to DIM could be attributed to the increased detoxification and oxidative defense in males. Overall, this study identified the endocrine disruption and reproductive impairment potency of DIM and first elucidated its mechanisms of action in medaka. The differential responses to DIM (estrogenic activities in the male but antiestrogenic activities in the female) provided sensitive biomarkers characteristic of each sex. Considering the chemical stability and potent endocrine disturbance at low concentration, the application of DIM either as an antifouling or chemopreventive agent should be approached with caution in marine environments. PMID:27092574

  11. Salinity-dependent Toxicity Assay of Silver Nanocolloids Using Medaka Eggs.

    PubMed

    Kataoka, Chisato; Kashiwada, Shosaku

    2016-01-01

    Salinity is an important characteristic of the aquatic environment. For aquatic organisms it defines the habitats of freshwater, brackish water, and seawater. Tests of the toxicity of chemicals and assessments of their ecological risks to aquatic organisms are frequently performed in freshwater, but the toxicity of chemicals to aquatic organisms depends on pH, temperature, and salinity. There is no method, however, for testing the salinity dependence of toxicity to aquatic organisms. Here, we used medaka (Oryzias latipes) because they can adapt to freshwater, brackish water, and seawater. Different concentrations of embryo-rearing medium (ERM) (1x, 5x, 10x, 15x, 20x, and 30x) were employed to test the toxicity of silver nanocolloidal particles (SNCs) to medaka eggs (1x ERM and 30x ERM have osmotic pressures equivalent to freshwater and seawater, respectively). In six-well plastic plates, 15 medaka eggs in triplicate were exposed to SNCs at 10 mg/L(-1) in different concentrations of ERM at pH 7 and 25 °C in the dark. We used a dissecting microscope and a micrometer to measure heart rate per 15 sec and eye diameter on day 6 and full body length of the larvae on hatching day (section 4). The embryos were observed until hatching or day 14; we then counted the hatching rate every day for 14 days (section 4). To see silver accumulation in embryos, we used inductively coupled plasma mass spectrometry to measure the silver concentration of test solutions (section 5) and dechorionated embryos (section 6).The toxicity of the SNCs to medaka embryos obviously increased with increasing salinity. This new method allows us to test the toxicity of chemicals in different salinities. PMID:27023020

  12. Identification and developmental expression of leucine-rich repeat-containing G protein-coupled receptor 6 (lgr6) in the medaka fish, Oryzias latipes.

    PubMed

    Deguchi, Tomonori; Kawasaki, Takashi; Ohnishi, Hiroe; Yuba, Shunsuke; Takahashi, Toshio

    2012-07-01

    G protein-coupled receptors are critical regulators of diverse developmental processes such as oocyte maturation, fertilization, gastrulation, and organogenesis. To further study the molecular mechanisms underlying these processes, we cloned and characterized the orphan leucine-rich repeat-containing G protein-coupled receptor 6 (LGR6), a stem cell marker in mammalian hair follicles, in medaka fish, Oryzias latipes. To examine the expression pattern of lgr6, we performed whole-mount in situ hybridization (WISH) during embryogenesis. The expression of lgr6 was first detected as a band in the anterior part of the posterior brain vesicle in 0.5-1 day post fertilization (dpf) embryos. This band disappeared by 2 dpf, but new signals appeared in the otic vesicles bordering the original band and also detected in the nasal placode and posterior lateral line primordia. At later stages (3-5 dpf), lgr6 was widely expressed in the brain, otic vesicle, neuromasts, root of the pectoral fin, cranial cartilage, and gut. Then, we conducted more detailed expression analysis of lgr6 in adult gut using WISH and immunohistochemical staining. Lgr6-positive cells were detected in the crypt-like proliferative zone and in parts of the villus. We also performed RT-PCR of mRNAs from different tissues. The lgr6 mRNA was found highest in the kidney and gill. The transcript was also present in the brain, heart, liver, spleen, intestine, skeletal muscle, testis, and ovary, similar to that of mammalian LGR6. These results suggest that medaka lgr6 plays an important role in organ development during embryogenesis and serves as a good molecular marker for future studies of postembryonic organ-specific development in mammals. PMID:22576653

  13. Relative Validity and Reproducibility of a Brief-Type Self-Administered Diet History Questionnaire for Japanese Children Aged 3–6 Years: Application of a Questionnaire Established for Adults in Preschool Children

    PubMed Central

    Asakura, Keiko; Haga, Megumi; Sasaki, Satoshi

    2015-01-01

    Background Dietary intake assessment and subsequent dietary education or intervention in young children is important in decreasing prevalence of various noncontagious diseases in adulthood. Validation of diet assessment questionnaires for preschool children has just started in Japan. In this study, we rearranged the brief-type self-administered diet history questionnaire (BDHQ), a convenient diet assessment questionnaire that is widely used in a range of situations for adults, for use in children aged 3–6 years (BDHQ3y) and then validated the BDHQ3y in Japanese children. Methods The guardians of 61 children aged 3–4 years completed the BDHQ3y twice at an interval of 1 month, along with a 3-nonconsecutive-day diet record (DR) between the two administrations of the BDHQ3y. Dietary intakes for energy and 42 selected nutrients were estimated using both the DR and the BDHQ3y. Mean intakes estimated by the two methods were compared, and correlation coefficients were calculated. Reproducibility of the BDHQ3y estimates was investigated using intra-class correlation coefficients (ICCs). Results No significant differences in mean intakes estimated by the DR and the BDHQ3y were observed for one- to two-thirds of energy and examined nutrients. The median of Pearson correlation coefficients between intakes energy-adjusted by the residual method was 0.31 (interquartile range, 0.24 to 0.38). The median ICC was 0.72 (interquartile range, 0.63 to 0.76) for the crude nutrient intakes. Conclusions Although the BDHQ3y might be a good candidate for dietary intake assessment in Japanese preschool children, its validity is currently moderate to low. Shortcomings should be overcome by obtaining and utilizing more information about children’s dietary habits. PMID:25843433

  14. Dazl is a critical player for primordial germ cell formation in medaka

    PubMed Central

    Li, Mingyou; Zhu, Feng; Li, Zhendong; Hong, Ni; Hong, Yunhan

    2016-01-01

    The DAZ family genes boule, daz and dazl have conserved functions in primordial germ cell (PGC) migration, germ stem cell proliferation, differentiation and meiosis progression. It has remained unknown whether this family is required for PGC formation in developing embryos. Our recent study in the fish medaka (Oryzias latipes) has defined dnd as the critical PGC specifier and predicted the presence of additional factors essential for PGC formation. Here we report that dazl is a second key player for medaka PGC formation. Dazl knockdown did not prevent PGC formation even in the absence of normal somatic structures. It turned out that a high level of Dazl protein was maternally supplied and persisted until gastrulation, and hardly affected by two antisense morpholino oligos targeting the dazl RNA translation. Importantly, microinjection of a Dazl antibody remarkably reduced the number of PGCs and even completely abolished PGC formation without causing detectable somatic abnormality. Therefore, medaka PGC formation requires the Dazl protein as maternal germ plasm component, offering first evidence that dazl is a critical player in PGC formation in vivo. Our results demonstrate that antibody neutralization is a powerful tool to study the roles of maternal protein factors in PGC development in vivo. PMID:27328644

  15. Germ cells are essential for sexual dimorphism in the medaka gonad

    PubMed Central

    Kurokawa, Hiromi; Saito, Daisuke; Nakamura, Shuhei; Katoh-Fukui, Yuko; Ohta, Kohei; Baba, Takashi; Morohashi, Ken-ichiro; Tanaka, Minoru

    2007-01-01

    To further elucidate the roles of germ cells in the sex differentiation of gonads, we have used the medaka, a teleost fish, to generate mutants that lack germ cells from the onset of gonadogenesis by the morpholino-mediated knockdown of cxcr4. The resulting germ-cell-deficient medaka show female-to-male sex reversal of their secondary sex characteristics, accompanied by increased levels of androgen and reduced levels of estrogen. A failure to maintain granulosa cells or estrogen-producing cells also occurs at early stages of sex differentiation in the cxcr4 morphants, before the initiation of gonadal morphogenesis. In contrast, androgen-producing cells are unaffected in germ-cell-deficient medaka of either sex. In addition, a single tube-like gonad that expresses male-specific genes is formed in these mutants irrespective of the genetic sex. Significantly, each of these mutant phenotypes occurs in a somatic cell-autonomous manner, suggesting that gonadal somatic cells are predisposed toward male development in the absence of germ cells. This highlights the importance of germ cells in the sexual dimorphism of the gonads. PMID:17940041

  16. Dazl is a critical player for primordial germ cell formation in medaka.

    PubMed

    Li, Mingyou; Zhu, Feng; Li, Zhendong; Hong, Ni; Hong, Yunhan

    2016-01-01

    The DAZ family genes boule, daz and dazl have conserved functions in primordial germ cell (PGC) migration, germ stem cell proliferation, differentiation and meiosis progression. It has remained unknown whether this family is required for PGC formation in developing embryos. Our recent study in the fish medaka (Oryzias latipes) has defined dnd as the critical PGC specifier and predicted the presence of additional factors essential for PGC formation. Here we report that dazl is a second key player for medaka PGC formation. Dazl knockdown did not prevent PGC formation even in the absence of normal somatic structures. It turned out that a high level of Dazl protein was maternally supplied and persisted until gastrulation, and hardly affected by two antisense morpholino oligos targeting the dazl RNA translation. Importantly, microinjection of a Dazl antibody remarkably reduced the number of PGCs and even completely abolished PGC formation without causing detectable somatic abnormality. Therefore, medaka PGC formation requires the Dazl protein as maternal germ plasm component, offering first evidence that dazl is a critical player in PGC formation in vivo. Our results demonstrate that antibody neutralization is a powerful tool to study the roles of maternal protein factors in PGC development in vivo. PMID:27328644

  17. Mutant Medaka fish having a deficiency in otolith-vestibular system and their behavior in microgravity.

    PubMed

    Ijiri, K

    2000-07-01

    Vestibular and visual senses are two major factors fish use for controlling their posture under 1 G conditions. From various studies in the past (parabolic flights and some ground-laboratory experiments), I came to have a hypothesis that "heavily eye-dependent" fish are tolerant to microgravity (micro-G). Theoretically, for "heavily eye-dependent" fish, the following three types may exist. (a) Fish having good eyesight, and having an ordinary sensitivity to gravity, (b) Fish having an ordinary eyesight, and having less sensitivity to gravity, (c) Fish having good eyesight, and having less sensitivity to gravity. In Medaka fish (Oryzias latipes), these three types have successfully been obtained. In this paper, the behavior of such different types of Medaka fish under micro-G will be studied by use of parabolic flights of an airplane. The ground-laboratory experiments are also reported, which focus on the contribution of both vestibular and visual senses to the posture control for each of three types of Medaka fish. PMID:12697536

  18. 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

  19. 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.

  20. In vivo visual reporter system for detection of estrogen-like substances by transgenic medaka.

    PubMed

    Kurauchi, Kanta; Nakaguchi, Yoshitsugu; Tsutsumi, Makiko; Hori, Hirosi; Kurihara, Ryo; Hashimoto, Shinya; Ohnuma, Ryoko; Yamamoto, Yoshikazu; Matsuoka, Sumiko; Kawai, Shin'Ichiro; Hirata, Takashi; Kinoshita, Masato

    2005-04-15

    Detection of endocrine disrupting chemicals, in particular, environmental estrogens with living organisms, has many advantages if compared to chemical analysis. The screening of novel pollutants with meaningful endpoints, the integration of uptake, bioconcentration, and excretion as well as the evaluation of endocrine disrupting effects with respect to toxicity require in vivo biotests for estrogen-like substances (ELSs). Critical disadvantages of whole organism biotests are their low sensitivity and the need for laborious and time-consuming work. To overcome these problems, we have developed a transgenic medaka strain harboring the green fluorescence protein (GFP) gene driven by choriogenin H gene regulatory elements. Choriogenin H is an egg envelope protein induced by estrogens in the liver. With yolk sac larvae of this strain, GFP induction in liver was observed 24 h after onset of aqueous exposure to 0.63 nM 17beta-estradiol (E2), 0.34 nM ethynylestradiol, or 14.8 nM estrone. Furthermore, concentrated sewage treatment effluent induced GFP expression. Comparison of E2 equivalents estimated by GFP-induction in transgenic medaka, a YES assay, and GC/MS showed detection limits in the same order of magnitude. These results indicated that the sensitivity of the transgenic medaka strain was sufficient for application as an alternative model in monitoring environmental water samples for ELSs. PMID:15884374

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

    PubMed

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

    2016-01-01

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

  2. Ethanol Disrupts Chondrification of the Neurocranial Cartilages in Medaka Embryos without Affecting Aldehyde Dehydrogenase 1A2 (Aldh1A2) Promoter Methylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Medaka (Oryzias latipes) embryos at different developmental stages were exposed to ethanol for 48 h, then allowed to hatch. Teratogenic effects were evaluated in hatchlings after examining chondrocranial cartilage deformities. Ethanol disrupted cartilage development in medaka in a dose and developme...

  3. TALENs-mediated gene disruption of myostatin produces a larger phenotype of medaka with an apparently compromised immune system.

    PubMed

    Chiang, Yi-An; Kinoshita, Masato; Maekawa, Shun; Kulkarni, Amod; Lo, Chu-Fang; Yoshiura, Yasutoshi; Wang, Han-Ching; Aoki, Takashi

    2016-01-01

    Although myostatin, a suppressor of skeletal muscle development and growth, has been well studied in mammals, its function in fish remains unclear. In this study, we used a popular genome editing tool with high efficiency and target specificity (TALENs; transcription activator-like effector nucleases) to mutate the genome sequence of myostatin (MSTN) in medaka (Oryzias latipes). After the TALEN pair targeting OlMyostatin was injected into fertilized medaka eggs, mutant G0 fish carrying different TALENs-induced frameshifts in the OlMSTN coding sequence were mated together in order to transmit the mutant sequences to the F1 generation. Two F1 mutants with frameshifted myostatin alleles were then mated to produce the F2 generation, and these F2 OlMSTN null (MSTN(-/-)) medaka were evaluated for growth performance. The F2 fish showed significantly increased body length and weight compared to the wild type fish at the juvenile and post-juvenile stages. At the post-juvenile stage, the average body weight of the MSTN(-/-) medaka was ∼25% greater than the wild type. However, we also found that when the F3 generation were challenged with red spotted grouper nervous necrosis virus (RGNNV), the expression levels of the interferon-stimulated genes were lower than in the wild type, and the virus copy number was maintained at a high level. We therefore conclude that although the MSTN(-/-) medaka had a larger phenotype, their immune system appeared to be at least partially suppressed or undeveloped. PMID:26578247

  4. A Stenohaline Medaka, Oryzias woworae, Increases Expression of Gill Na(+), K(+)-ATPase and Na(+), K(+), 2Cl(-) Cotransporter 1 to Tolerate Osmotic Stress.

    PubMed

    Juo, Jiun-Jang; Kang, Chao-Kai; Yang, Wen-Kai; Yang, Shu-Yuan; Lee, Tsung-Han

    2016-08-01

    The present study aimed to evaluate the osmoregulatory mechanism of Daisy's medaka, O. woworae,as well as demonstrate the major factors affecting the hypo-osmoregulatory characteristics of euryhaline and stenohaline medaka. The medaka phylogenetic tree indicates that Daisy's medaka belongs to the celebensis species group. The salinity tolerance of Daisy's medaka was assessed. Our findings revealed that 20‰ (hypertonic) saltwater (SW) was lethal to Daisy's medaka. However, 62.5% of individuals survived 10‰ (isotonic) SW with pre-acclimation to 5‰ SW for one week. This transfer regime, "Experimental (Exp.) 10‰ SW", was used in the following experiments. After 10‰ SW-transfer, the plasma osmolality of Daisy's medaka significantly increased. The protein abundance and distribution of branchial Na(+), K(+)-ATPase (NKA) and Na(+), K(+), 2Cl(-) cotransporter 1 (NKCC1) were also examined after transfer to 10‰ SW for one week. Gill NKA activity increased significantly after transfer to 10‰ SW. Meanwhile, elevation of gill NKA αα-subunit protein-abundance was found in the 10‰ SW-acclimated fish. In gill cross-sections, more and larger NKA-immunoreactive (NKA-IR) cells were observed in the Exp. 10‰ SW medaka. The relative abundance of branchial NKCC1 protein increased significantly after transfer to 10‰ SW. NKCC1 was distributed in the basolateral membrane of NKA-IR cells of the Exp. 10‰ SW group. Furthermore, a higher abundance of NKCC1 protein was found in the gill homogenates of the euryhaline medaka, O. dancena, than in that of the stenohaline medaka, O. woworae. PMID:27498801

  5. Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment.

    PubMed

    Rochman, Chelsea M; Kurobe, Tomofumi; Flores, Ida; Teh, Swee J

    2014-09-15

    Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (<1mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3 months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research. PMID:24995635

  6. Effects of a Lifestyle-Based Physical Activity Intervention on Medical Expenditure in Japanese Adults: A Community-Based Retrospective Study

    PubMed Central

    2016-01-01

    Background. This study aimed to investigate whether a lifestyle-based physical activity program could contribute to reduced medical expenditure. Methods. The study participants were 60 adults aged 63.1 (standard deviation, 4.4) years in the intervention group; the case-control group consisted of 300 adults who were randomly selected from Japan's national health insurance system. This community-based retrospective study incorporated a 3-year follow-up. Results. The total and outpatient medical expenditure in the intervention group were significantly lower than in the control group: total expenditure, $US640.4/year; outpatient expenditure, $369.1/year. The odds ratio for outpatient visiting was 6.47-fold higher in the control than in the intervention group. Conclusion. Our study suggests that a health program to promote physical activity can result in reduced total medical expenditure, outpatient medical expenditure, and possibly also inpatient medical expenditure. PMID:27493963

  7. Combined effects of eating alone and living alone on unhealthy dietary behaviors, obesity and underweight in older Japanese adults: Results of the JAGES.

    PubMed

    Tani, Yukako; Kondo, Naoki; Takagi, Daisuke; Saito, Masashige; Hikichi, Hiroyuki; Ojima, Toshiyuki; Kondo, Katsunori

    2015-12-01

    We examined whether eating alone is associated with dietary behaviors and body weight status, and assessed the modifying effects of cohabitation status in older Japanese people. Data from the 2010 Japan Gerontological Evaluation Study, with a self-reported questionnaire for 38,690 men and 43,674 women aged ≥65 years, were used. Eating status was classified as eating with others, sometimes eating alone, or exclusively eating alone. We calculated adjusted prevalence ratios (APRs) of unhealthy dietary behaviors, obesity, and underweight, adjusting for age, education, income, disease, and dental status using Poisson regression. Overall, 16% of men and 28% of women sometimes or exclusively ate alone. Among those who exclusively ate alone, 56% of men and 68% of women lived alone. Men who exclusively ate alone were 3.74 times more likely to skip meals than men who ate with others. Among men who exclusively ate alone, those who lived alone had a higher APR than men who lived with others. Compared with subjects who ate and lived with others, the APRs of being obese (BMI ≥ 30.0 kg/m(2)) among men who exclusively ate alone were 1.34 (1.01-1.78) in those who lived alone and 1.17 (0.84-1.64) in those who lived with others. These combined effects of eating and living alone were weaker in women, with a potential increase in the APRs among those who ate alone despite living with others. Men who exclusively ate alone were more likely to be underweight (BMI < 18.5 kg/m(2)) than men who ate with others in both cohabitation statuses. Eating alone and living alone may be jointly associated with higher prevalence of obesity, underweight and unhealthy eating behaviors in men. PMID:26116391

  8. Virtual CT morphometry of lower limb long bones for estimation of the sex and stature using postmortem Japanese adult data in forensic identification.

    PubMed

    Hishmat, Asmaa Mohammed; Michiue, Tomomi; Sogawa, Nozomi; Oritani, Shigeki; Ishikawa, Takaki; Fawzy, Irene Atef; Hashem, Mohamed Abdel Mohsen; Maeda, Hitoshi

    2015-09-01

    The application of computed tomography (CT) is useful for the documentation of whole-body anatomical data on routine autopsy, virtual reconstruction of skeletal structure, objective measurements, and reassessment by repetitive analyses. In addition, CT data processing facilitates volumetric and radiographic density analyses. Furthermore, a recently developed automated analysis system markedly improved the performance and accuracy of three-dimensional (3D) reconstruction. The present study investigated virtual CT morphometry of lower limb long bones, including the femur, tibia, fibula, and first metatarsus, to estimate the sex and stature using postmortem CT data of forensic autopsy cases of Japanese over 19 years of age (total n = 259, 150 males and 109 females). Bone mass volumes, lengths, and total CT attenuation values of bilateral femurs, tibias, and fibulas correlated with the stature; however, the mean CT attenuation (HU) values showed age-dependent decreases. Correlations with the stature were similar for the lengths and mass volumes of the femur, tibia, and fibula (r = 0.77-0.85) but were higher for the mass volume of the first metatarsus (r = 0.77 for right and r = 0.58 for left). In addition, the ratio of the bone volume to the length of each bone showed the most significant sex-related differences (males > females with accuracy of 75.8-98.1 %). These findings indicate the usefulness of virtual CT morphometry of individual lower limb long bones, including volumetry, to estimate the sex and stature in identification. PMID:26156452

  9. Comparison of Social Trust's effect on suicide ideation between urban and non-urban areas: The Case of Japanese Adults in 2006.

    PubMed

    Yamamura, Eiji

    2015-09-01

    An increasing number of studies have addressed the determinants of suicide. Social capital is a key factor in preventing suicide. However, little is known about the experience of suicide ideation using subjective values. From the viewpoint of suicide prevention, it is worth examining how people think of suicide. This paper attempts to examine the effect of social capital on suicide ideation. Furthermore, the paper compares the effect of social capital between urban and non-urban areas. In this paper, urban areas are equivalent to mega-cities with populations over one million. Non-urban areas are cities with populations of less than one million, towns and villages. Individual-level data from the Japanese General Social Surveys (JGSSs) are used. The survey, which was conducted in 2006, provides information about the subjective value of suicide ideation. The survey was answered by 1413 subjects with a mean age of 54.5. Of the subjects, 49% were male. Social trust is used to measure the degree of social capital, and the outcome of interest is suicide ideation within the past 5 years. After controlling for various factors, the major findings are that both individual-level social trust and social trust accumulated in one's residential administrative district reduce the probability that one will consider suicide. After dividing the sample into urban and non-urban residents, particularized trust plays a role in deterring suicide ideation in urban areas, while generalized trust plays a role in deterring suicide ideation in non-urban areas. The effect of each type of trust depends on its scarcity in residential areas. PMID:26218455

  10. [Japanese adults' general beliefs about changes in the ability to remember from childhood to old age as measured by the General Beliefs about Memory Instrument (GBMI)].

    PubMed

    Kinjo, Hikari; Shimizu, Hiroyuki

    2012-12-01

    This study examined and compared beliefs about the ability to remember of three groups of adults: 99 young, 97 middle-aged, and 104 older adults. The beliefs were assessed by asking participants to indicate the expected trajectory over the lifespan on a graphic rating scale, the General Beliefs about Memory Instrument (GBMI) (Lineweaver & Hertzog, 1998). The results showed the following. Although all age groups expect a decline in the ability to remember with age with the peak around 20-30 years old, older adults perceive an age-related sharp decline later in life than the other age groups do. All age groups perceive that remembering names is more affected by age than any other memory abilities. The trajectory of age decline in remembering in general coincides with that in remembering trivia. All age groups believe that the ability to remember at the age of 10 is as good as at the age of 40. All age groups responded to the scales based mainly on the abilities based on their experiences. PMID:23379080

  11. Lifestyle characteristics assessment of Japanese in Pittsburgh, USA.

    PubMed

    Hirooka, Nobutaka; Takedai, Teiichi; D'Amico, Frank

    2012-04-01

    Lifestyle-related chronic diseases such as cancer and cardiovascular disease are the greatest public health concerns. Evidence shows Japanese immigrants to a westernized environment have higher incidence of lifestyle-related diseases. However, little is known about lifestyle characteristics related to chronic diseases for Japanese in a westernized environment. This study is examining the gap in lifestyle by comparing the lifestyle prevalence for Japanese in the US with the Japanese National Data (the National Health and Nutrition Survey in Japan, J-NHANS) as well as the Japan National Health Promotion in the twenty-first Century (HJ21) goals. Japanese adults were surveyed in Pittsburgh, USA, regarding their lifestyle (e.g., diet, exercise, smoking, stress, alcohol, and oral hygiene). The prevalence was compared with J-NHANS and HJ21 goals. Ninety-three responded (response rate; 97.9%). Japanese men (n = 38) and women (n = 55) in Pittsburgh smoke less than Japanese in Japan (P < 0.001 for both genders). Japanese in Pittsburgh perform less physical activity in daily life and have lower prevalence of walking more than 1 h per day (P < 0.001 for both genders). Japanese women in Pittsburgh have significantly higher prevalence of stress than in Japan (P = 0.004). Japanese men in Pittsburgh do not reach HJ21 goal in weight management, BMI, use of medicine or alcohol to sleep, and sleep quality. Japanese women in Pittsburgh do not reach HJ21 goal in weight management and sleep quality. In conclusion, healthy lifestyle promotion including exercise and physical activity intervention for Japanese living in a westernized environment is warranted. PMID:21874580

  12. Japanese Interest in "Hotaru" (Fireflies) and "Kabuto-Mushi" (Japanese Rhinoceros Beetles) Corresponds with Seasonality in Visible Abundance.

    PubMed

    Takada, Kenta

    2012-01-01

    Seasonal changes in the popularity of fireflies [usually Genji-fireflies (Luciola cruciata Motschulsky) in Japan] and Japanese rhinoceros beetles [Allomyrina dichotoma (Linne)] were investigated to examine whether contemporary Japanese are interested in visible emergence of these insects as seasonal events. The popularity of fireflies and Japanese rhinoceros beetles was assessed by the Google search volume of their Japanese names, "Hotaru" and "Kabuto-mushi" in Japanese Katakana script using Google Trends. The search volume index for fireflies and Japanese rhinoceros beetles was distributed across seasons with a clear peak in only particular times of each year from 2004 to 2011. In addition, the seasonal peak of popularity for fireflies occurred at the beginning of June, whereas that for Japanese rhinoceros beetles occurred from the middle of July to the beginning of August. Thus seasonal peak of each species coincided with the peak period of the emergence of each adult stage. These findings indicated that the Japanese are interested in these insects primarily during the time when the two species are most visibly abundant. Although untested, this could suggest that fireflies and Japanese rhinoceros beetles are perceived by the general public as indicators or symbols of summer in Japan. PMID:26466535

  13. Air Writing as a Technique for the Acquisition of Sino-japanese Characters by Second Language Learners

    ERIC Educational Resources Information Center

    Thomas, Margaret

    2015-01-01

    This article calls attention to a facet of the expertise of second language (L2) learners of Japanese at the intersection of language, memory, gesture, and the psycholinguistics of a logographic writing system. Previous research has shown that adult L2 learners of Japanese living in Japan (similarly to native speakers of Japanese) often…

  14. 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

  15. Development of retroviral vectors for insertional mutagenesis in medaka haploid cells.

    PubMed

    Lin, Fan; Liu, Qizhi; Yuan, Yongming; Hong, Yunhan

    2015-12-01

    Insertional mutagenesis (IM) by retrovirus (RV) is a high-throughput approach for interrogating gene functions in model species. Haploid cell provides a unique system for genetic screening by IM and prosperous progress has been achieved in mammal cells. However, little was known in lower vertebrate cells. Here, we report development of retroviral vectors (rvSAchCVgfp, rvSAchCVpf and rvSAchSTpf) and establishment of IM library in medaka haploid cells. Each vector contains a modified gene trapping (GT) cassette, which could extend the mutated cell population including GT insertions not in-frame or in weakly expressed genes. Virus titration determined by flow cytometry showed that rvSAchSTpf possessed the highest supernatant virus titer (1.5×10(5)TU/ml) in medaka haploid cell, while rvSAchCVpf produced the lowest titer (2.8×10(4)TU/ml). However, quantification of proviral DNAs in transduced cells by droplet digital PCR (ddPCR) demonstrated that the "real titer" may be similar among the three vectors. Furthermore, an IM library was established by FACS of haploid cells transduced with rvSAchCVgfp at a MOI of 0.1. A single copy RV integration in the majority of cells was confirmed by ddPCR in the library. Notably, there was a significant decrease of haploid cell percentage after FACS, suggesting potential trapping for survival/growth essential genes. Our results demonstrated successful development of retroviral vectors for IM in medaka haploid cells, serving for haploid genetic screening of host factors for virus infection and genes underlying certain cellular processes in fish model. PMID:26192464

  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. Live imaging of osteoclast inhibition by bisphosphonates in a medaka osteoporosis model

    PubMed Central

    Yu, Tingsheng; Witten, Paul Eckhard; Huysseune, Ann; Buettner, Anita; To, Thuy Thanh; Winkler, Christoph

    2016-01-01

    ABSTRACT Osteoclasts are bone-resorbing cells derived from the monocyte/macrophage lineage. Excess osteoclast activity leads to reduced bone mineral density, a hallmark of diseases such as osteoporosis. Processes that regulate osteoclast activity are therefore targeted in current osteoporosis therapies. To identify and characterize drugs for treatment of bone diseases, suitable in vivo models are needed to complement cell-culture assays. We have previously reported transgenic medaka lines expressing the osteoclast-inducing factor receptor activator of nuclear factor κB ligand (Rankl) under control of a heat shock-inducible promoter. Forced Rankl expression resulted in ectopic osteoclast formation, as visualized by live imaging in fluorescent reporter lines. This led to increased bone resorption and a dramatic reduction of mineralized matrix similar to the situation in humans with osteoporosis. In an attempt to establish the medaka as an in vivo model for osteoporosis drug screening, we treated Rankl-expressing larvae with etidronate and alendronate, two bisphosphonates commonly used in human osteoporosis therapy. Using live imaging, we observed an efficient, dose-dependent inhibition of osteoclast activity, which resulted in the maintenance of bone integrity despite an excess of osteoclast formation. Strikingly, we also found that bone recovery was efficiently promoted after inhibition of osteoclast activity and that osteoblast distribution was altered, suggesting effects on osteoblast-osteoclast coupling. Our data show that transgenic medaka lines are suitable in vivo models for the characterization of antiresorptive or bone-anabolic compounds by live imaging and for screening of novel osteoporosis drugs. PMID:26704995

  18. TGFβ-2 signaling is essential for osteoblast migration and differentiation during fracture healing in medaka fish.

    PubMed

    Takeyama, Kazuhiro; Chatani, Masahiro; Inohaya, Keiji; Kudo, Akira

    2016-05-01

    TGFβ is known as a canonical coupling factor based on its effects on bone formation and bone resorption. There are 3 different isoforms of it related to bone metabolism in mammals. TGFβ function in vivo is complicated, and each isoform shows a different function. Since TGFβs are secreted during inflammation accompanied by the release of latent TGFβ from inside of the bones where they are stored in the extracellular matrix, TGFβ function is potentially related to fracture healing. Although a few reports examined the TGFβ expression during fracture healing, the function of TGFβ in this process is poorly understood. To investigate TGFβ function during fracture healing in vivo, we used the fracture healing model of the medaka fish, which enabled us to observe the behavior and function of living cells in response to a bone-specific injury. RNA in-situ hybridization analysis showed that only tgfβ-2 of the 4 TGFβ isoforms in medaka was expressed in the bone-forming region. To examine the TGFβ-2 function for bone formation by osteoblasts, we used a medaka transgenic line, Tg (type X collagen: GFP); and the results revealed that type X collagen-positive immature osteoblasts migrated to the fracture site and differentiated to osterix-positive osteoblasts. However, only a few type X collagen-positive osteoblasts exhibited BrdU incorporation after the fracture. Then we inhibited TGFβ signaling by using a chemical TGFβ receptor kinase inhibitor (SB431542), and demonstrated that inhibition of TGFβ strongly impaired osteoblast migration and differentiation. In addition, this TGFβ inhibitor reduced the RANKL expression and caused a delay of osteoclast differentiation. Our findings thus demonstrated that TGFβ-2 functioned specifically during fracture healing to stimulate the migration of osteoblasts as well as the differentiation of osteoblasts and osteoclasts. PMID:26947892

  19. TCDD Induced Pericardial Edema and Relative COX-2 Expression in Medaka (Oryzias Latipes) Embryos

    PubMed Central

    Dong, Wu; Matsumura, Fumio; Kullman, Seth W.

    2010-01-01

    Exposure to dioxin and other aryl hydrocarbon receptor (AhR) ligands results in multiple, specific developmental cardiovascular phenotypes including pericardial edema and circulatory failure in small aquarium fish models. Although phenotypes are well described, mechanistic underpinnings for such toxicities remain elusive. Here we suggest that AhR activation results in stimulation of inflammation and “eicosanoid” pathways, which contribute to the observed developmental, cardiovascular phenotypes. We demonstrate that medaka embryos exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (0.05–1 ppb) during early development result in a dose-related increase in the prevalence of pericardial edema and that this phenotype correlates with an increase in cyclooxygenase-2 (COX-2) gene expression. Those individuals exhibiting the edema phenotype had significantly greater COX-2 mRNA than their nonedematous cohort. Selective pharmacological inhibition of COX-2, with NS-398, and genetic knock down of COX-2 with a translation initiation morpholino significantly attenuated prevalence and severity of edema phenotype. Subsequently, exposures of medaka embryos to arachidonic acid (AA) resulted in recapitulation of the pericardial edema phenotype and significantly increased COX-2 expression only in those individuals exhibiting the edema phenotype compared with their nonedematous cohort. AA exposure does not result in significant induction of cytochrome P450 1A expression, suggesting that pericardial edema can be induced independent of AhR/aryl hydrocarbon receptor nuclear translocator/dioxin response element interactions. Results from this study demonstrate that developmental exposure to TCDD results in an induction of inflammatory mediators including COX-2, which contribute to the onset, and progression of heart dysmorphogenesis in the medaka model. PMID:20801906

  20. Japanese Media in English.

    ERIC Educational Resources Information Center

    Tanaka, Sachiko Oda

    1995-01-01

    Describes the use of English in the media in Japan, focusing on the role and history of English-language newspapers, radio, and television programs, as well as the proliferation of English-language films shown in Japanese cinemas. Discusses the implications of English in the Japanese media. (20 references) (MDM)

  1. Japanese Quality Control Circles.

    ERIC Educational Resources Information Center

    Nishiyama, Kazuo

    In recent years, United States scholars with an interest in international business and organizational communication have begun to notice the success of Japanese "quality control circles." These are small groups, usually composed of seven to ten workers, who are organized at the production levels within most large Japanese factories. A typical…

  2. The Japanese containerless experiments

    NASA Technical Reports Server (NTRS)

    Azuma, Hisao

    1990-01-01

    There are three sets of Japanese containerless experiments. The first is Drop dynamics research. It consists of acoustic levitation and large amplitude drop oscillation. The second is Optical materials processing in an acoustic levitation furnace. And the third is Electrostatic levitator development by two different Japanese companies.

  3. The Japanese American Story.

    ERIC Educational Resources Information Center

    Fukei, Budd

    This book presents a view of the Japanese American experience from the time of their immigration to this country in the 1800s to their acculturation into American society in the 1970s. Topics dealt with include the prejudice and mistrust experienced by the Japanese immigrants in this country, particularly their evacuation and internment in…

  4. Japanese Elementary School Education.

    ERIC Educational Resources Information Center

    Stevenson, Harold W.

    1991-01-01

    Discusses the development of Japanese elementary education in the context of three periods of its history. Considers salient characteristics of Japanese elementary schools and teaching procedures; these include curriculum; social and moral education; classroom environment; teachers; afterschool classes; college entrance examinations; the kyoiku…

  5. Extensive Reading in Japanese

    ERIC Educational Resources Information Center

    Hitosugi, Claire Ikumi; Day, Richard R.

    2004-01-01

    This article discusses how we incorporated an extensive reading (ER) program into a second semester Japanese course at the University of Hawai'i using Japanese children's literature. After summarizing the ten principles of ER, we describe how we addressed six critical issues faced while introducing ER into the course. We also discuss the outcomes…

  6. Phototoxicity of TiO2 Nanoparticles under Solar Radiation to Two Aquatic Species: Daphnia magna and Japanese Medaka

    EPA Science Inventory

    One target of development and application of TiO2 nanoparticles (nano-TiO2) is photochemical degredation of contaminants and photo-killing of microbes and fouling organisms. However, few ecotoxicological studies have focused on this aspect of nano-TiO2, specifically whether this ...

  7. EFFECTS OF O,P'-DDT ON GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES). (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...

  8. 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...

  9. Use of gene expression data to determine effects on gonad phenotype in Japanese medaka after exposure to trenbolone or estradiol

    EPA Science Inventory

    Various aquatic bioassays using one of several fish species have been developed or are in the process of being developed by organizations like the US Environmental Protection Agency and the Office of Economic Cooperation and Development for testing potential endocrine disrupting ...

  10. 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.

  11. The Development of Sentences in Japanese Narrative Discourse.

    ERIC Educational Resources Information Center

    Clancy, Patricia M.

    Sentences produced by children and adults in telling stories are analyzed, with particular emphasis on developmental trends in sentence length, the degree of cohesion between clauses, and the internal coherence of sentence content. Subjects for the study were 10 adults and 60 Japanese children in six different age groups. Each subject was…

  12. Children's On-Line Processing of Scrambling in Japanese

    ERIC Educational Resources Information Center

    Suzuki, Takaaki

    2013-01-01

    This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in…

  13. Conserved function of medaka pink-eyed dilution in melanin synthesis and its divergent transcriptional regulation in gonads among vertebrates.

    PubMed

    Fukamachi, Shoji; Asakawa, Shuichi; Wakamatsu, Yuko; Shimizu, Nobuyoshi; Mitani, Hiroshi; Shima, Akihiro

    2004-11-01

    Medaka is emerging as a model organism for the study of vertebrate development and genetics, and its effectiveness in forward genetics should prove equal to that of zebrafish. Here, we identify by positional cloning a gene responsible for the medaka i-3 albino mutant. i-3 larvae have weakly tyrosinase-positive cells but lack strongly positive and dendritic cells, suggesting loss of fully differentiated melanophores. The region surrounding the i-3 locus is syntenic to human 19p13, but a BAC clone covering the i-3 locus contained orthologs located at 15q11-13, including OCA2 (P). Medaka P consists of 842 amino acids and shares approximately 65% identity with mammalian P proteins. The i-3 mutation is a four-base deletion in exon 13, which causes a frameshift and truncation of the protein. We detected medaka P transcripts in melanin-producing eyeballs and (putative) skin melanophores on embryos and an alternatively spliced form in the non-melanin-producing ovary or oocytes. The mouse p is similarly expressed in gonads, but not alternatively spliced. This is the first isolation of nonmammalian P, the functional mechanism of action of which has not yet been elucidated, even in mammals. Further investigation of the functions of P proteins and the regulation of their expression will provide new insight into body color determination and gene evolution. PMID:15579703

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

    SciTech Connect

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

    1995-10-01

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

  15. A new model for fish ion regulation: identification of ionocytes in freshwater- and seawater-acclimated medaka (Oryzias latipes).

    PubMed

    Hsu, Hao-Hsuan; Lin, Li-Yih; Tseng, Yung-Che; Horng, Jiun-Lin; Hwang, Pung-Pung

    2014-07-01

    The ion regulation mechanisms of fishes have been recently studied in zebrafish (Danio rerio), a stenohaline species. However, recent advances using this organism are not necessarily applicable to euryhaline fishes. The euryhaline species medaka (Oryzias latipes), which, like zebrafish, is genetically well categorized and amenable to molecular manipulation, was proposed as an alternative model for studying osmoregulation during acclimation to different salinities. To establish its suitability as an alternative, the present study was conducted to (1) identify different types of ionocytes in the embryonic skin and (2) analyze gene expressions of the transporters during seawater acclimation. Double/triple in situ hybridization and/or immunocytochemistry revealed that freshwater (FW) medaka contain three types of ionocyte: (1) Na(+)/H(+) exchanger 3 (NHE3) cells with apical NHE3 and basolateral Na(+)-K(+)-2Cl(-) cotransporter (NKCC), Na(+)-K(+)-ATPase (NKA) and anion exchanger (AE); (2) Na(+)-Cl(-) cotransporter (NCC) cells with apical NCC and basolateral H(+)-ATPase; and (3) epithelial Ca(2+) channel (ECaC) cells [presumed accessory (AC) cells] with apical ECaC. On the other hand, seawater (SW) medaka has a single predominant ionocyte type, which possesses apical cystic fibrosis transmembrane conductance regulator (CFTR) and NHE3 and basolateral NKCC and NKA and is accompanied by smaller AC cells that express lower levels of basolateral NKA. Reciprocal gene expressions of decreased NHE3, AE, NCC and ECaC and increased CFTR and NKCC in medaka gills during SW were revealed by quantative PCR analysis. PMID:24842048

  16. Essential techniques for introducing medaka to a zebrafish laboratory--towards the combined use of medaka and zebrafish for further genetic dissection of the function of the vertebrate genome.

    PubMed

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

    2011-01-01

    The medaka, Oryzias latipes, a small egg-laying freshwater fish, is one of the three vertebrate model organisms in which genome-wide phenotype-driven mutant screens have been carried out. Despite a number of large-scale screens in zebrafish, a substantial number of mutants with new distinct phenotypes were identified in similar large-scale screens in the medaka. This observed difference in phenotype is due to the two species having a unique combination of genetic, biological and evolutional properties. The two genetic models share a whole-genome duplication event over that of tetrapods; however, each has independently specialized or lost the function of one of the two paralogues. The two fish species complement each other as genetic systems as straightforward comparison of phenotypes, ease of side-by-side analysis using the same techniques and simple and inexpensive husbandry of mutants make these small teleosts quite powerful in combination. Furthermore, both have draft genome sequences and bioinformatic tools available that facilitate further genetic dissection including whole-genome approaches. Together with the gene-driven approach to generate gene knockout mutants of the fish models, the two fish models complement the mouse in genetically dissecting vertebrate genome functions. The external embryogenesis and transparent embryos of the fish allow systematic isolation of embryonic lethal mutations, the most difficult targets in mammalian mutant screens. This chapter will describe how to work with both medaka and zebrafish almost as one species in a lab, focusing on medaka and highlighting the differences between the medaka and zebrafish systems. PMID:21805266

  17. Low bioavailability of silver nanoparticles presents trophic toxicity to marine medaka (Oryzias melastigma).

    PubMed

    Wang, Jian; Wang, Wen-Xiong

    2014-07-15

    Concerns for the potential risks of silver nanoparticles (AgNPs) to aquatic organisms have increased. The present study investigated the trophic transfer of AgNPs from brine shrimp (Artemia salina) nauplii to marine medaka. We found that the aggregated AgNPs (20 and 80 nm) and well dispersed 80-nm AgNPs (stabilized by 20 μM Tween 20) could be readily accumulated by brine shrimp, while far less well-dispersed 20-nm AgNPs were accumulated. The assimilation efficiency (AE) of AgNPs in medaka fed AgNPs-contaminated brine shrimp was low (<6%), resulting in a low trophic transfer efficiency (0.01-0.04) after 28 days of chronic dietary exposure. However, such low bioavailability of dietary AgNPs could inhibit the whole-body Na+/K+-ATPase and superoxide dismutase (SOD) activity in the fish within the first 2 weeks of exposure. Significant (p<0.05, two-way ANOVA) inhibition occurred in the high AgNPs-contaminated brine shrimp treatment over 28 days of chronic exposure. Furthermore, reduced growth and water content percentage were also observed in fish fed high dosages of AgNPs-contaminated brine shrimp. Our study highlighted the potential of trophically available AgNPs in bringing toxicity to the marine fish. PMID:24937273

  18. Oestrogen reporter transgenic medaka for non-invasive evaluation of aromatase activity.

    PubMed

    Spirhanzlova, Petra; Leleu, Mathilde; Sébillot, Anthony; Lemkine, Gregory F; Iguchi, Taisen; Demeneix, Barbara A; Tindall, Andrew J

    2016-01-01

    Vertebrate reproduction involves complex steroid hormone interplay and inter-conversion. A critical element in maintaining sex steroid levels is the enzyme aromatase (cytochrome P450 19A1) which converts androgens to oestrogens. In turn oestrogen signalling is targeted by numerous chemicals, from pharmaceuticals to agricultural chemicals, both frequent sources of contamination in waste waters and consequently rivers. Although many models are now available to address disruption of oestrogen signalling, there are currently no published protocols allowing discrimination between alterations in testosterone metabolism and in oestrogenic signalling. It was with this limitation in mind that we optimised this protocol. We show using a 48h protocol that pre-feeding fry of the choriogenin h-gfp (chgh-gfp) medaka line are sensitive to 0.05nM EE2 (15ng/L), within the range of the lowest published observable physiological effect concentrations for medaka. In addition, co-treatment with testosterone can reveal potential effects of test substances on aromatase enzymatic activity. As the measurements are visualised in real-time without affecting embryo viability, repeated measures are possible. We demonstrate the ability of this model to detect oestrogen receptor agonists, aromatisable androgens, P450 aromatase activity modulators and selective oestrogen response modulators. Importantly, the range of this assay is physiologically relevant. PMID:26352216

  19. 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).

  20. Marine medaka ATP-binding cassette (ABC) superfamily and new insight into teleost Abch nomenclature

    PubMed Central

    Jeong, Chang-Bum; Kim, Bo-Mi; Kang, Hye-Min; Choi, Ik-Young; Rhee, Jae-Sung; Lee, Jae-Seong

    2015-01-01

    The ABC gene family is recognized as one of the largest gene families in all kingdoms of life. Although many genes involved in the ABC superfamily have been annotated from several fish species, information on large sets of the ABC superfamily and their evolutionary characterization are still unclear. In the marine medaka Oryzias melastigma, 50 ABC transporters were identified with bioinformatics-aided in silico analyses, and their full-length cDNA sequences were characterized. Phylogenetic analysis revealed that they could be classified into the eight subfamilies (A–H) that include all members of all ABC subfamilies. Interestingly, several teleosts’ Abcg members were closely clustered with Abch members in a distinctive clade. The abch gene was also observed in the coelacanth and the spotted gar, suggesting that this gene was retained from a bilaterian ancestor and that a gene loss event recently occurred in the tetrapod lineage. In teleosts, the nomenclature of previously annotated abcg genes should be considered carefully, as they form a distinctive clade with the marine medaka abch subfamily and other teleost abch genes, but not with the members of the Abcg subfamily. PMID:26472499

  1. Ectopic expression of single transcription factors directs differentiation of a medaka spermatogonial cell line.

    PubMed

    Thoma, Eva C; Wagner, Toni U; Weber, Isabell P; Herpin, Amaury; Fischer, Andreas; Schartl, Manfred

    2011-08-01

    The capability to form all cell types of the body is a unique feature of stem cells. However, many questions remain concerning the mechanisms regulating differentiation potential. The derivation of spermatogonial cell lines (SGs) from mouse and human, which can differentiate across germ-layer borders, suggested male germ cells as a potential stem cell source in addition to embryonic stem cells. Here, we present a differentiation system using an SG of the vertebrate model organism Oryzias latipes (medaka). We report differentiation of this cell line into 4 different ectodermal and mesodermal somatic cell types. In addition to differentiation into adipocytes by retinoic acid treatment, we demonstrate for the first time that directed differentiation of an SG can be induced by ectopic expression of single transcription factors, completely independent of culture conditions. Transient transfection with mitf-m, a transcription factor that has been shown to induce differentiation into melanocytes in medaka embryonic stem cells, resulted in the formation of the same cell type in spermatogonia. Similarly, the formation of neuron-like cells and matrix-depositing osteoblasts was induced by ectopic expression of mash1 and cbfa1, respectively. Interestingly, we found that the expression of all mentioned fate-inducing transcription factors leads to recapitulation of the temporal pattern of marker gene expression known from in vivo studies. PMID:21090990

  2. 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.

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

    PubMed Central

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

    2008-01-01

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

  4. 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. PMID:25652692

  5. 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...

  6. How the Japanese work.

    PubMed

    Chambers, D W

    1998-01-01

    The Japanese do not work harder or even use different approaches so much as they aim for a different result--one that balances process and results and extends the definition of quality beyond the product itself to include cost and convenience to the customer as well. Ten methods of the Japanese kaizen culture of work are presented with applications and contrasts to American dentistry. PMID:9929991

  7. Transgenic medaka that overexpress growth hormone have a skin color that does not indicate the activation or inhibition of somatolactin-α signal.

    PubMed

    Komine, Ritsuko; Nishimaki, Toshiyuki; Kimura, Tetsuaki; Oota, Hiroki; Naruse, Kiyoshi; Homma, Noriko; Fukamachi, Shoji

    2016-06-10

    Teleosts have two paralogous growth-hormone receptors (GHRs). In vitro studies demonstrated that both receptors bind to and transmit the signal of the growth hormone (GH). However, one of the GHRs (GHR1) was shown to bind more strongly to somatolactin-α (SLα), a fish-specific peptide hormone that is closely related to GH, and is, therefore, termed somatolactin receptor (SLR). In this study, we questioned whether the dual binding of GHR1/SLR causes a crosstalk (reciprocal activation or inhibition) between GH and SLα signals in vivo. For this purpose, we newly established a transgenic medaka that overexpresses GH (Actb-GH:GFP) and assessed its phenotype. The body weight of these transgenic medaka is about twice that of wild-type fish, showing that functional GH was successfully overexpressed in Actb-GH:GFP fish. The transgenic medaka, especially female fish, showed severe infertility, which was a common side effect in GH transgenesis. The skin color, which reflects the effects of SLα most conspicuously in medaka, was similar to that of neither the SLα-overexpressing nor the SLα-deficient medaka, indicating that GH overexpression does not enhance or suppress the SLα signal. We also verified that a transgenic medaka that overexpressed SLα grew and reproduced normally. Therefore, regardless of the in vitro binding relationships, the GH and SLα signals seem not to crosstalk significantly in vivo even when these hormones are overexpressed. PMID:26945627

  8. Now You Hear It, Now You Don't: Vowel Devoicing in Japanese Infant-Directed Speech

    ERIC Educational Resources Information Center

    Fais, Laurel; Kajikawa, Sachiyo; Amano, Shigeaki; Werker, Janet F.

    2010-01-01

    In this work, we examine a context in which a conflict arises between two roles that infant-directed speech (IDS) plays: making language structure salient and modeling the adult form of a language. Vowel devoicing in fluent adult Japanese creates violations of the canonical Japanese consonant-vowel word structure pattern by systematically…

  9. The contemporary JAEA Japanese voxel phantoms.

    PubMed

    Sato, Kaoru; Takahashi, Fumiaki

    2012-03-01

    Average adult Japanese male (JM-103 phantom) and female (JF-103 phantom) voxel (volume pixel) phantoms were newly constructed by modifying the JM and JF phantoms previously developed at Japan Atomic Energy Agency. The JM-103 and JF-103 have average characteristics with respect to organ masses and body sizes. Their tissue segmentations were based on International Commission on Radiological Protection (ICRP) Publication 103. The anatomical and dosimetric characteristics of JM-103 and JF-103 were compared with those of ICRP adult reference male (AM phantom) and female (AF phantoms) phantoms. This study discusses their anatomical and dosimetric characteristics, and applications to the dose assessment of the atomic bomb survivors. PMID:22003186

  10. Effects of body-color mutations on vitality: an attempt to establish easy-to-breed see-through medaka strains by outcrossing.

    PubMed

    Ohshima, Ayaka; Morimura, Noriko; Matsumoto, Chizuru; Hiraga, Ami; Komine, Ritsuko; Kimura, Tetsuaki; Naruse, Kiyoshi; Fukamachi, Shoji

    2013-09-01

    "See-through" strains of medaka are unique tools for experiments: their skin is transparent, and their internal organs can be externally monitored throughout life. However, see-through fish are less vital than normally pigmented wild-type fish, which allows only skilled researchers to make the most of their advantages. Expecting that hybrid vigor (heterosis) would increase the vitality, we outcrossed two see-through strains (SK(2) and STIII) with a genetically distant wild-type strain (HNI). Fish with the see-through phenotypes were successfully restored in the F2 generation and maintained as closed colonies. We verified that genomes of these hybrid see-through strains actually consisted of approximately 50% HNI and approximately 50% SK(2) or STIII alleles, but we could not obtain evidence supporting improved survival of larvae or fecundity of adults, at least under our breeding conditions. We also found that four of the five see-through mutations (b(g8), i-3, gu, and il-1 but not lf) additively decrease viability. Given that heterosis could not overwhelm the viability-reducing effects of the see-through mutations, easy-to-breed see-through strains will only be established by other methods such as conditional gene targeting or screening of new body-color mutations that do not reduce viability. PMID:23893740

  11. Individualistic Striving and Group Dynamics of Fifth- and Eighth-Grade Japanese Boys.

    ERIC Educational Resources Information Center

    Shwalb, David W.; And Others

    1991-01-01

    Individualistic and competitive striving and group dynamics were compared for 42 fifth grade and 42 eighth grade Japanese boys in central Tokyo using a card-stacking procedure. Results are discussed in terms of social loafing versus social striving and behavior patterns of Japanese adults. (SLD)

  12. Research Note: The Effect of Visuals on Listening Comprehension: A Study of Japanese Learners' Listening Strategies.

    ERIC Educational Resources Information Center

    Seo, Kyoko

    2002-01-01

    Aims to identify listening comprehension strategies used by adult Japanese native speakers and monolingual Australian learners of the Japanese language. Investigates how two different listening contexts (audiovisual and audio-only) may influence listeners' choice of strategies and how the strategies chosen relate to learners' proficiency.…

  13. Acquaintance or Fiancee: Pragmatic Differences in Requests between Japanese and Americans.

    ERIC Educational Resources Information Center

    Kubota, Mitsuo

    1996-01-01

    A study investigated differences in the speech styles used in making requests among five native speakers of Japanese (JJ), five American learners of Japanese (AJ), and Americans speaking English (AE) and their implications for intercultural communication. All subjects were adults. Data were elicited in role-plays of a scenario including the…

  14. Comparison of postmenopausal endogenous sex hormones among Japanese, Japanese Brazilians, and non-Japanese Brazilians

    PubMed Central

    2011-01-01

    Background Differences in sex hormone levels among populations might contribute to the variation in breast cancer incidence across countries. Previous studies have shown higher breast cancer incidence and mortality among Japanese Brazilians than among Japanese. To clarify the difference in hormone levels among populations, we compared postmenopausal endogenous sex hormone levels among Japanese living in Japan, Japanese Brazilians living in the state of São Paulo, and non-Japanese Brazilians living in the state of São Paulo. Methods A cross-sectional study was conducted using a control group of case-control studies in Nagano, Japan, and São Paulo, Brazil. Participants were postmenopausal women older than 55 years of age who provided blood samples. We measured estradiol, estrone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), testosterone and free testosterone by radioimmunoassay; bioavailable estradiol by the ammonium sulfate precipitation method; and sex hormone-binding globulin (SHBG) by immunoradiometric assay. A total of 363 women were included for the present analyses, comprising 185 Japanese, 44 Japanese Brazilians and 134 non-Japanese Brazilians. Results Japanese Brazilians had significantly higher levels of estradiol, bioavailable estradiol, estrone, testosterone and free testosterone levels, and lower SHBG levels, than Japanese. Japanese Brazilians also had significantly higher levels of bioavailable estradiol, estrone and DHEAS and lower levels of SHBG and androstenedione than non-Japanese Brazilians. Levels of estradiol, testosterone and free testosterone, however, did not differ between Japanese Brazilians and non-Japanese Brazilians. These differences were observed even after adjustment for known breast cancer risk factors. We also found an increase in estrogen and androgen levels with increasing body mass index, but no association for most of the other known risk factors. Conclusions We found higher levels of estrogens and androgens in

  15. Dental fear of Japanese residents in the United States.

    PubMed Central

    Domoto, P.; Weinstein, P.; Kamo, Y.; Wohlers, K.; Fiset, L.; Tanaka, A.

    1991-01-01

    The purpose of this study was to investigate dental fear in a sample of Japanese adults and to make preliminary comparisons with a previously described US sample. The survey instrument was translated into Japanese and then translated back into English and was sent to 839 Japanese residing in the Seattle area. A total of 419 (49.9%) usable questionnaires were returned. Results indicate a level of fear higher than the US population (only 17.9% were not at all afraid). Fear level did not vary by age; most respondents (73.3%) acquired their fear in early childhood. While reported utilization was lower than the American sample, the percentage of Japanese respondents who reported being hurt at the last appointment was high (68.0%). Japanese respondents indicated that 35% of dentists appeared to be in a hurry, hurry being associated with being hurt. Japanese coping practices appeared to differ from the American sample. For example, 14.7% of the Japanese whereas 28.2% of the US sample requested the dentist to stop treatment. PMID:1814250

  16. Otolith Formation in A Mutant Medaka Fish with A Deficiency in Gravity- Sensing

    NASA Astrophysics Data System (ADS)

    Mizuno, R.; Ijiri, K.

    Formation of otoliths in Medaka fish (Oryzias latipes) were studied in the normal (wild-type) fish and in a mutant strain called ha. In the normal fish, two pairs of otoliths (Lapillus and Sagitta) are formed during embryonic development, and the most posterior otolith (Asteriscus) are formed later (about 30 days after hatching). In the mutant strain ha, though Sagittae are formed, Lapilli are absent at hatching. Asterisca are formed normally. Various abnormalities in the formation of Sagittae were detected in ha strain, however, they eventually took normal shapes and positions on the maculae. After hatching, in some ha fish, Lapilli are formed. On 30 days and 40 days after hatching, the appearance of Lapilli were examined by X-ray photography. The results showed that some fis h had a complete pair, some had only one otolith either at the right or left side, and the rest of fish lacked Lapilli completely.

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

    PubMed Central

    Yang, Huiping; Tiersch, Terrence R.

    2009-01-01

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

  18. Medaka Fish Embryo Developed for STS-78 Life and Microgravity Spacelab (LMS)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Launched on June 20, 1996, the STS-78 mission's primary payload was the Life and Microgravity Spacelab (LMS), which was managed by the Marshall Space Flight Center (MSFC). During the 17 day space flight, the crew conducted a diverse slate of experiments divided into a mix of life science and microgravity investigations. In a manner very similar to future International Space Station operations, LMS researchers from the United States and their European counterparts shared resources such as crew time and equipment. Five space agencies (NASA/USA, European Space Agency/Europe (ESA), French Space Agency/France, Canadian Space Agency /Canada, and Italian Space Agency/Italy) along with research scientists from 10 countries worked together on the design, development and construction of the LMS. This photo represents the development of Medaka Fish Embryos, one of the many studies of the LMS mission.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  1. Anchoring Ethinylestradiol Induced Gene Expression Changes with Testicular Morphology and Reproductive Function in the Medaka

    PubMed Central

    Miller, Hilary D.; Clark, Bryan W.; Hinton, David E.; Whitehead, Andrew; Martin, Stan; Kwok, Kevin W.; Kullman, Seth W.

    2012-01-01

    Environmental estrogens are ubiquitous in the environment and can cause detrimental effects on male reproduction. In fish, a multitude of effects from environmental estrogens have been observed including altered courting behavior and fertility, sex reversal, and gonadal histopathology. However, few studies in fish assess the impacts of estrogenic exposure on a physiological endpoint, such as reproduction, as well as the associated morphologic response and underlying global gene expression changes. This study assessed the implications of a 14 day sub-chronic exposure of ethinylestradiol (EE2; 1.0 or 10.0 µg/L EE2) on male medaka fertility, testicular histology and testicular gene expression. The findings demonstrate that a 14 day exposure to EE2 induced impaired male reproductive capacity and time- and dose-dependent alterations in testicular morphology and gene expression. The average fertilization rate/day following the exposure for control, 1.0 and 10.0 µg/L EE2 was 91.3% (±4.4), 62.8% (±8.3) and 28.8% (±5.8), respectively. The testicular morphologic alterations included increased germ cell apoptosis, decreased germinal epithelium and thickening of the interstitium. These changes were highly associated with testicular gene expression changes using a medaka-specific microarray. A pathway analysis of the differentially expressed genes emphasized genes and pathways associated with apoptosis, cell cycle and proliferation, collagen production/extracellular matrix organization, hormone signaling, male reproduction and protein ubiquitination among others. These findings highlight the importance of anchoring global gonadal gene expression changes with morphology and ultimately with tissue/organ function. PMID:23300682

  2. Japanese Encephalitis: Frequently Asked Questions

    MedlinePlus

    ... of Page How long does the Japanese encephalitis vaccination last? The duration of protection is unknown. For ... What are the side effects of Japanese encephalitis vaccination? Pain and tenderness are the most commonly reported ...

  3. New Frontiers for Japanese Youth

    ERIC Educational Resources Information Center

    Tucker, Frank H.

    1974-01-01

    Japanese literature, television, movies, and school texts from 1935 to 1955 are analyzed for their influence and contribution to Japanese youths' pioneering spirit and frontiermindedness. "Asian Affairs" is published by the American-Asian Educational Exchange, New York. (DE)

  4. 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

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

    SciTech Connect

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

    2009-02-27

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

  6. Cultural Competence in Business Japanese.

    ERIC Educational Resources Information Center

    Koike, Shohei

    Cultural competence in business Japanese requires more than superficial knowledge of business etiquette. One must truly understand why Japanese people think and act differently from their American counterparts. For example, instruction in the use of Japanese taxis must be accompanied by instruction in the concept and implications of seating order…

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

    PubMed

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

    2016-09-01

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

  8. 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

  9. The multidimensional nature of hyperspeech: evidence from Japanese vowel devoicing.

    PubMed

    Martin, Andrew; Utsugi, Akira; Mazuka, Reiko

    2014-08-01

    We investigate the hypothesis that infant-directed speech is a form of hyperspeech, optimized for intelligibility, by focusing on vowel devoicing in Japanese. Using a corpus of infant-directed and adult-directed Japanese, we show that speakers implement high vowel devoicing less often when speaking to infants than when speaking to adults, consistent with the hyperspeech hypothesis. The same speakers, however, increase vowel devoicing in careful, read speech, a speech style which might be expected to pattern similarly to infant-directed speech. We argue that both infant-directed and read speech can be considered listener-oriented speech styles-each is optimized for the specific needs of its intended listener. We further show that in non-high vowels, this trend is reversed: speakers devoice more often in infant-directed speech and less often in read speech, suggesting that devoicing in the two types of vowels is driven by separate mechanisms in Japanese. PMID:24813573

  10. Nucleus Course in Japanese.

    ERIC Educational Resources Information Center

    Akiyama, Nobuo; Flamm, Carol S.

    The "Nucleus Course in Japanese," based on the Institute of Modern Languages'"Situational Reinforcement" approach, is designed for 80 to 100 hours of instruction. Each lesson has several sections--Response drills, Appropriate Response Sequence, and Reading. Most of the lessons also include optional sections with Sentences for Repetition or a…

  11. Reflexives in Japanese

    ERIC Educational Resources Information Center

    Kishida, Maki

    2011-01-01

    The purpose of this dissertation is to reconsider reflexives in Japanese through the following three steps: (a) separation of genuine reflexive elements from elements that are confounded as reflexives, (b) classification of reflexive anaphors into subtypes based on their semantic difference, and (c) classification of predicates that occur with…

  12. Reciprocal Predicates in Japanese.

    ERIC Educational Resources Information Center

    Ishii, Yasuo

    A study of reciprocals in Japanese compares two kinds: (1) a verbal suffix "aw"; and (2) an NP argument "otagai." Although "otagai" appears to be taken care of by syntactic binding theory, it is proposed that there is no evidence for the existence of a syntactic position of the object NP in the case of "aw." The suffix can be characterized as…

  13. Japanese Temple Geometry

    ERIC Educational Resources Information Center

    Vincent, Jill; Vincent, Claire

    2004-01-01

    Between the 17th and 19th centuries, the Japanese government closed its borders to the outside world in an attempt to become more powerful. Foreign books were banned, people could not travel, and foreigners were not allowed to enter the country. One result of this isolation was the flourishing of sangaku--wooden tablets inscribed with intricately…

  14. I Can Learn Japanese.

    ERIC Educational Resources Information Center

    Rubin, Michael; Funato, Makiko

    This set of materials for Japanese second language instruction was designed for students who can be taught most effectively through a functional, conversational approach. It is intended as a supplement to the regular course of study so that all students, regardless of ability level, can be provided with an effective instructional program. It…

  15. Japanese Experiences: "Hentai" Narratives

    ERIC Educational Resources Information Center

    Kama, Amit

    2011-01-01

    For those acquainted with Japanese lesbian, gay, bisexual, and transgender (LGBT) issues, "Queer Voices from Japan" can be good reading. But with only 1 of its 22 chapters informative for researchers, those interested in LGBT youth studies will only indirectly gain insight into a non-Western perspective on youth and sexuality.

  16. Experimental Analysis of Japanese Martial Art Nihon-Kempo

    ERIC Educational Resources Information Center

    Kuragano, Tetsuzo; Yokokura, Saburo

    2012-01-01

    With a male, adult subject, this study measured the punch force and kick force of the Japanese martial art Nihon-Kempo, the movements of the dominant (right) arm, leg, and the movements of the legs using timed synchronization. Using an electromyogram (EMG), the relationship between the variation of punch force and the variation of the electrical…

  17. Arterial stiffness of lifelong Japanese female pearl divers.

    PubMed

    Tanaka, Hirofumi; Tomoto, Tsubasa; Kosaki, Keisei; Sugawara, Jun

    2016-05-15

    Japanese female pearl divers called Ama specialize in free diving in the cold sea for collecting foods and pearls in oysters. Exercising in the water combined with marked bradycardia and pressor responses provides a circulatory challenge to properly buffer or cushion elevated cardiac pulsations. Because Ama perform repeated free dives throughout their lives, it is possible that they may have adapted similar arterial structure and function to those seen in diving mammals. We compared arterial stiffness of lifelong Japanese pearl divers with age-matched physically inactive adults living in the same fishing villages. A total of 115 Japanese female pearl divers were studied. Additionally, 50 physically inactive adults as well as 33 physically active adults (participating in community fitness programs) living in the same coastal villages were also studied. There were no differences in age (∼65 yr), body mass index, and brachial blood pressure between the groups. Measures of arterial stiffness, cardio-ankle vascular index and β-stiffness index were lower (P < 0.05) in pearl divers and physically active adults than in their physically inactive peers. Augmentation pressure and augmentation index adjusted for the heart rate of 75 beats/min were lower (P < 0.05) in pearl divers than in other groups. These results indicate that lifelong Japanese pearl divers demonstrate reduced arterial stiffness and arterial wave reflection compared with age-matched physically inactive peers living in the same fishing villages. PMID:26984889

  18. Creating a Global Cultural Consciousness in a Japanese EFL Classroom

    ERIC Educational Resources Information Center

    Aubrey, Scott

    2009-01-01

    Recently, culture has taken an important role in language education. In this view, creating a global cultural consciousness among second language (L2) students can help bridge the gap between linguistic ability and functional intercultural communication. This paper, which makes reference to Japanese adult EFL learners, justifies the body of…

  19. Theoretical Implications of Contemporary Brain Science for Japanese EFL Learning

    ERIC Educational Resources Information Center

    Clayton, John Lloyd

    2015-01-01

    Recent advances in brain science show that adult native Japanese speakers utilize a different balance of language processing routes in the brain as compared to native English speakers. Biologically this represents the remarkable flexibility of the human brain to adapt universal human cognitive processes to fit the specific needs of linguistic and…

  20. Japanese Women's Perceptions of Intimate Partner Violence (IPV)

    ERIC Educational Resources Information Center

    Nagae, Miyoko; Dancy, Barbara L.

    2010-01-01

    Intimate partner violence (IPV) is a problem in Japan. The purpose is to describe IPV as perceived by a purposive sample of 11 Japanese adult females who were in a heterosexual marriage at the time of IPV. We used a cross-sectional, retroactive, qualitative description research design with individual, fact-to-face in depth interviews. At the time…

  1. 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.

  2. 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

  3. Immunotoxicity of trenbolone acetate in Japanese quail

    USGS Publications Warehouse

    Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.

    2007-01-01

    Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.

  4. Developmental Sentence Scoring for Japanese (DSSJ)

    PubMed Central

    Miyata, Susanne; MacWhinney, Brian; Otomo, Kiyoshi; Sirai, Hidetosi; Oshima-Takane, Yuriko; Hirakawa, Makiko; Shirai, Yasuhiro; Sugiura, Masatoshi; Itoh, Keiko

    2014-01-01

    This paper reports on the development and use of the Developmental Sentence Scoring for Japanese (DSSJ), a new morpho-syntactical measure for Japanese constructed after the model of the English Developmental Sentence Scoring model (Lee, 1974). Using this measure, we calculated DSSJ scores for 84 children divided into six age groups between 2;8 and 5;2 on the basis of 100-sentence samples collected from free-play child-adult conversations. The analysis showed a high correlation of the DSSJ overall score with the Mean Length of Utterance. The analysis of the DSSJ subarea scores revealed large variations between these subarea scores for children with similar overall DSSJ scores. When investigating the high-scoring children (over 1 SD over group average), most children scored high in three to five subareas, but the combination of scores for these subareas varied from child to child. It is concluded that DSSJ is a valuable tool especially for the language acquisition research. The overall DSSJ score reliably reflects the overall morpho-syntactic development of Japanese children, and the subarea scores provide specific information on individual acquisition patterns. PMID:25414535

  5. Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis.

    PubMed

    Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

    2015-04-01

    High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1-8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species. PMID:25762582

  6. Flowering of Japanese astronomy

    SciTech Connect

    Kozai, Y.

    1988-06-01

    A development history is presented for Japanese astronomy from the 6th century to the present day, together with a status report and account of future plans. About 500 professionals currently belong to the Astronomical Society of Japan. Tokyo's Mitaka Observatory employs a staff of about 70 astronomers; most modern astronomical instruments, however, have been installed at sites outside the Tokyo area. The limitations of present instruments are notably severe for astronomers working in the visible and IR wavelengths.

  7. Suicide of Japanese Youth.

    PubMed

    Iga, M

    1981-01-01

    The uniquely intense stress due to the Examination Hell (shiken jigoku) not only generates a basic drive for Japan's economic success but also contributes to a high rate of young people's suicide. This paper discusses the major factors in the intensity of Japanese stress on both institutional and psychological levels. The social structural factors which convert stress to suicide are analyzed in terms of weak ego; restraint on aggression; a lack of social resources; and views of life, death and suicide. Japanese views of life, death and suicide are treated in terms of Absolute phenomenalism, the original form of Shintoism, to which Buddhism and Confucianism have been adjusted in Japan. Japanese phenomenalism affects suicide through its three aspects: animism, present-time oriented small groupism, and the absolute acceptance of the established social order. Confusion and conflict since World War II have increased anomic suicides; however, elements of fatalistic suicide (due to excessive formal or informal social regulations) and altruistic suicide (due to excessive formal or informal social regulations) and altruistic suicide (due to strong social integration) are evident. Suicide is still a highly institutionalized adjustment mechanism in Japan. PMID:7233479

  8. In vivo and in silico analyses of estrogenic potential of bisphenol analogs in medaka (Oryzias latipes) and common carp (Cyprinus carpio).

    PubMed

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

    2015-10-01

    Various studies have demonstrated the estrogenic effect of bisphenol A (BPA), a member of bisphenol analogs (BPs), in in vitro and in vivo assays. However, limited data are available on the estrogenic potentials and risks of other BPs in aquatic organisms. In addition, the estrogenic effect of chemicals is known to have species-specific responses in teleost fish. The objective of this study was to evaluate the potential estrogenic effects of BPs on the medaka (Oryzias latipes) and common carp (Cyprinus carpio) using in vivo and in silico assays. Our quantitative real-time PCR analyses revealed that the expression levels of several hepatic estrogen-responsive biomarker genes in male medaka responded to various types and concentrations of BPs in a dose-response manner. The order of in vivo estrogenic potencies of BPs was as follows: BPC≈BPAF>BPB>BPA⋙BPP. To further investigate the interaction potential of BPs with medaka estrogen receptor α (ERα) in silico, a three-dimensional model of the ERα ligand-binding domain (LBD) was built and docking simulations were performed. The docking simulation analysis revealed that BPC interaction potential for medaka ERα LBD was the most potent, followed by BPAF and BPA. Comparing this with carp ERα LBD revealed that the interaction potentials of these BPs to medaka ERα LBD were more stable than to carp ERα LBD. Furthermore, we identified key amino acid residues in medaka ERα LBD that interacted with BPC (Glu356, Arg397, and Cys533), BPAF (Thr350 and Glu356), and BPA (Glu356 and Met424), and found some differences in these key amino acid residues between medaka and carp ERα LBDs. These results of in vivo and in silico analyses showed potential estrogenic effects of BPs in teleost fish, and they also indicated that the differences in interaction potentials and key amino acid residues between medaka and carp ERα LBDs may be due to the differences between the species and estrogenic potencies of the selected BPs. PMID

  9. Autosomal gsdf acts as a male sex initiator in the fish medaka

    PubMed Central

    Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

    2016-01-01

    Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

  10. vox homeobox gene: a novel regulator of midbrain-hindbrain boundary development in medaka fish?

    PubMed

    Fabian, Peter; Pantzartzi, Chrysoula N; Kozmikova, Iryna; Kozmik, Zbynek

    2016-03-01

    The midbrain-hindbrain boundary (MHB) is one of the key organizing centers of the vertebrate central nervous system (CNS). Its patterning is governed by a well-described gene regulatory network (GRN) involving several transcription factors, namely, pax, gbx, en, and otx, together with signaling molecules of the Wnt and Fgf families. Here, we describe the onset of these markers in Oryzias latipes (medaka) early brain development in comparison to previously known zebrafish expression patterns. Moreover, we show for the first time that vox, a member of the vent gene family, is expressed in the developing neural tube similarly to CNS markers. Overexpression of vox leads to profound changes in the gene expression patterns of individual components of MHB-specific GRN, most notably of fgf8, a crucial organizer molecule of MHB. Our data suggest that genes from the vent family, in addition to their crucial role in body axis formation, may play a role in regionalization of vertebrate CNS. PMID:26965282

  11. Reiterative expression of pax1 directs pharyngeal pouch segmentation in medaka.

    PubMed

    Okada, Kazunori; Inohaya, Keiji; Mise, Takeshi; Kudo, Akira; Takada, Shinji; Wada, Hiroshi

    2016-05-15

    A striking characteristic of vertebrate development is the pharyngeal arches, which are a series of bulges on the lateral surface of the head of vertebrate embryos. Although each pharyngeal arch is segmented by the reiterative formation of endodermal outpocketings called pharyngeal pouches, the molecular network underlying the reiterative pattern remains unclear. Here, we show that pax1 plays crucial roles in pouch segmentation in medaka (Oryzias latipes) embryos. Importantly, pax1 expression in the endoderm prefigures the location of the next pouch before the cells bud from the epithelium. TALEN-generated pax1 mutants did not form pharyngeal pouches posterior to the second arch. Segmental expression of tbx1 and fgf3, which play essential roles in pouch development, was almost non-existent in the pharyngeal endoderm of pax1 mutants, with disturbance of the reiterative pattern of pax1 expression. These results suggest that pax1 plays a key role in generating the primary pattern for segmentation in the pharyngeal endoderm by regulating tbx1 and fgf3 expression. Our findings illustrate the crucial roles of pax1 in vertebrate pharyngeal segmentation and provide insights into the evolutionary origin of the deuterostome gill slit. PMID:27034424

  12. Gender-specific transcriptional profiling of marine medaka (Oryzias melastigma) liver upon BDE-47 exposure.

    PubMed

    Yu, W K; Shi, Y F; Fong, C C; Chen, Y; van de Merwe, J P; Chan, Alice K Y; Wei, F; Bo, J; Ye, R; Au, Doris W T; Wu, Rudolf S S; Yang, M S

    2013-09-01

    Marine medaka (Oryzias melastigma) were exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) to investigate the gender-specific transcriptional profiles of liver tissue in response to this flame retardant. A cDNA library of O. melastigma was constructed, and 2304 clones were amplified from the library to fabricate a cDNA microarray. Sequences of these genes were assembled into 1800 sequences using Geneious, a bioinformatics software. Corresponding expressed sequence tags were blasted against the National Centre for Biotechnology Information non-redundant database and further classified into various biological categories according to the Gene Ontology project. Male and female three-month-old were fed a diet of BDE-47 contaminated Artemia at low dosage (290.3±172.3ng BDE-47/day) and high dosage (580.5±344.6ng BDE-47/day) for 5 and 21 days, respectively. The transcriptional profiles of O. melastigma liver were then generated by the species-specific cDNA microrarray. The results from microarray analysis suggested very different gene expression patterns between males and females for both BDE-47 exposure-dose and exposure-time, with male livers having stronger gene regulatory responses than female livers. Importantly, our results revealed that in male O. melastigma only, BDE-47 exposure may activate phosphoinositide-3-kinase and mitogen-activated protein kinase, proteins that play importance roles in cell growth, proliferation and survival. PMID:23962555

  13. 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.

  14. Reassessment of the function of somatolactin alpha in lipid metabolism using medaka mutant and transgenic strains

    PubMed Central

    2012-01-01

    Background Somatolactin alpha (SLa) is a fish-specific peptide hormone secreted from the pituitary. In medaka, SLa functions to darken the skin color and lack of SLa makes it pale. Transcription of SLa is enhanced or suppressed when fish are kept in dark or bright conditions, respectively, indicating SLa’s important role in background acclimation of the skin color. Bizarrely, however, the lack of SLa seems to cause the additional defect of increased triglycerides in organs, which could not be rescued (decreased) by its overexpression. Results To assess this enigmatic result, we investigated genetic (the SLa, Slc45a2, r, and Y genes) and nongenetic (age, fasting, water temperature, and background color) effects on hepatic triglycerides. These experiments found that percent hepatic triglycerides quickly change in response to external/internal environments. Effects of SLa seemed to be much less obvious, although it may increase the proportion of hepatic triglycerides at least during certain breeding conditions or under certain genetic backgrounds. Conclusions The present results do not exclude the possibility that SLa takes part in lipid metabolism or other physiological processes. However, we suggest that skin-color regulation is the only definite role of SLa so far demonstrated in this species. PMID:22827540

  15. Evolution of Different Y Chromosomes in Two Medaka Species, Oryzias dancena and O. latipes

    PubMed Central

    Takehana, Yusuke; Demiyah, Diana; Naruse, Kiyoshi; Hamaguchi, Satoshi; Sakaizumi, Mitsuru

    2007-01-01

    Although the sex-determining gene DMY has been identified on the Y chromosome in the medaka (Oryzias latipes), this gene is absent in most Oryzias species, suggesting that closely related species have different sex-determining genes. Here, we investigated the sex-determination mechanism in O. dancena, which does not possess the DMY gene. Since heteromorphic sex chromosomes have not been reported in this species, a progeny test of sex-reversed individuals produced by hormone treatment was performed. Sex-reversed males yielded all-female progeny, indicating that O. dancena has an XX/XY sex-determination system. To uncover the cryptic sex chromosomes, sex-linked DNA markers were screened using expressed sequence tags (ESTs) established in O. latipes. Linkage analysis of isolated sex-linked ESTs showed a conserved synteny between the sex chromosomes in O. dancena and an autosome in O. latipes. Fluorescence in situ hybridization (FISH) analysis of these markers confirmed that sex chromosomes of these species are not homologous. These findings strongly suggest an independent origin of sex chromosomes in O. dancena and O. latipes. Further analysis of the sex-determining region in O. dancena should provide crucial insights into the evolution of sex-determination mechanisms in vertebrates. PMID:17194774

  16. Proton-facilitated ammonia excretion by ionocytes of medaka (Oryzias latipes) acclimated to seawater.

    PubMed

    Liu, Sian-Tai; Tsung, Lin; Horng, Jiun-Lin; Lin, Li-Yih

    2013-08-01

    The proton-facilitated ammonia excretion is critical for a fish's ability to excrete ammonia in freshwater. However, it remains unclear whether that mechanism is also critical for ammonia excretion in seawater (SW). Using a scanning ion-selective electrode technique (SIET) to measure H(+) gradients, an acidic boundary layer was detected at the yolk-sac surface of SW-acclimated medaka (Oryzias latipes) larvae. The H(+) gradient detected at the surface of ionocytes was higher than that of keratinocytes in the yolk sac. Treatment with Tricine buffer or EIPA (a NHE inhibitor) reduced the H(+) gradient and ammonia excretion of larvae. In situ hybridization and immunochemistry showed that slc9a2 (NHE2) and slc9a3 (NHE3) were expressed in the same SW-type ionocytes. A real-time PCR analysis showed that transfer to SW downregulated branchial mRNA expressions of slc9a3 and Rhesus glycoproteins (rhcg1, rhcg2, and rhbg) but upregulated that of slc9a2. However, slc9a3, rhcg1, rhcg2, and rhbg expressions were induced by high ammonia in SW. This study suggests that SW-type ionocytes play a role in acid and ammonia excretion and that the Na(+)/H(+) exchanger and Rh glycoproteins are involved in the proton-facilitated ammonia excretion mechanism. PMID:23678031

  17. Characterization of assortative mating in medaka: Mate discrimination cues and factors that bias sexual preference.

    PubMed

    Utagawa, Umi; Higashi, Shoichi; Kamei, Yasuhiro; Fukamachi, Shoji

    2016-08-01

    Somatolactin alpha (SLα) is a peptide hormone that regulates skin color, and SLα-deficient and SLα-excess strains have been established in medaka (Oryzias latipes). Their skin colors differ conspicuously and males prefer to mate with females from the same strain. Pre-mating sexual isolation in this model vertebrate provides an ideal platform for investigating the molecular mechanisms of mate choice. Thus, we studied the sensory cues utilized by these fish to discriminate the same and different strains. When males were given a choice under monochromatic light, where the skin colors differed only in terms of brightness but not in hue, mating occurred but it was not assortative. This suggests that: (1) a visual cue is essential for mate discrimination rather than odor or acoustic cues; (2) the visual cue is color and not shape, size, or motion; and (3) the color cue needs to be perceived as the relative balance of brightness at multiple wavelengths rather than the brightness at a specific wavelength. In addition, we introduced another skin-color mutation into the SLα-excess strain and found that this new strain and the original SLα-excess strain, which also overexpressed SLα but exhibited distinct skin colors, preferred different colors. This demonstrates that SLα is not a primary determinant of sexual preference. The symmetrically biased sexual preferences of the SLα-deficient and SLα-excess strains may be acquired postnatally depending on their individual skin color or that of tank mates. PMID:27260680

  18. Influence of difenoconazole on lipid metabolism in marine medaka (Oryzias melastigma).

    PubMed

    Dong, Xiaocui; Li, Yan; Zhang, Lemeng; Zuo, Zhenghong; Wang, Chonggang; Chen, Meng

    2016-07-01

    Difenoconazole (DFZ) is a triazole fungicide that inhibits the biosynthesis of sterols in cell membranes and is widely used in agriculture for effectively treating fungal infections. However, there are few studies available addressing the effects of DFZ on lipid metabolism in marine fishes. The present study was conducted to investigate the effects of DFZ on lipid metabolism in marine medaka (Oryzias melastigma). After exposure to 1, 10, 100 and 1000 ng/L DFZ for 180 days, an increase in condition factor (CF), total lipids and polyunsaturated fatty acids (PUFA) contents accompanied with a decrease in saturated fatty acids was observed in the muscle of DFZ-exposed fish. The expression of peroxisome proliferator-activated receptor γ as well as retinoid X receptors in the muscle was up-regulated, which would be responsible for the lipid accumulation in the muscle. The elevation of Δ6-desaturase (FADS2) and Δ9-desaturase (SCD) mRNA levels in the muscle and liver might result in the increase of PUFA content. The increased CF index and total lipid amounts indicated that DFZ exposure could affect the health of fish. ∑SFA (sum of saturated fatty acids) and DHA (docosahexaenoic acid; 22:6n-3) concentrations decreased, and the levels of ∑PUFA and ∑n-6PUFA increased in the muscle, which suggested that DFZ exposure could change lipid metabolism and profiles in fish. PMID:27112457

  19. Sex and cultural differences in spatial performance between Japanese and North Americans.

    PubMed

    Sakamoto, Maiko; Spiers, Mary V

    2014-04-01

    Previous studies have suggested that Asians perform better than North Americans on spatial tasks but show smaller sex differences. In this study, we evaluated the relationship between long-term experience with a pictorial written language and spatial performance. It was hypothesized that native Japanese Kanji (a complex pictorial written language) educated adults would show smaller sex differences on spatial tasks than Japanese Americans or North Americans without Kanji education. A total of 80 young healthy participants (20 native Japanese speakers, 20 Japanese Americans-non Japanese speaking, and 40 North Americans-non Japanese speaking) completed the Rey Complex Figure Test (RCFT), the Mental Rotations Test (MRT), and customized 2D and 3D spatial object location memory tests. As predicted, main effects revealed men performed better on the MRT and RCFT and women performed better on the spatial object location memory tests. Also, as predicted, native Japanese performed better on all tests than the other groups. In contrast to the other groups, native Japanese showed a decreased magnitude of sex differences on aspects of the RCFT (immediate and delayed recall) and no significant sex difference on the efficiency of the strategy used to copy and encode the RCFT figure. This study lends support to the idea that intensive experience over time with a pictorial written language (i.e., Japanese Kanji) may contribute to increased spatial performance on some spatial tasks as well as diminish sex differences in performance on tasks that most resemble Kanji. PMID:24356949

  20. The Japanese Education System is a Failure, Say Some Japanese.

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    1997-01-01

    A Japanese editorial in an English-language daily harshly criticized Japanese education's failure to enhance students' spirit of independence; develop critical and artistic thinking skills; and promote social awareness and an international viewpoint. The United States finished fourth out of 60 in the (unpublicized) International Math Olympiad.…

  1. A physiologically-based pharmacokinetic model for disposition of 2,3,7,8-TCDD in fathead minnow and medaka.

    PubMed

    Parhizgari, Zahra; Li, James

    2014-05-01

    A physiologically-based pharmacokinetic model was developed for the disposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in 2 fish species--fathead minnow and medaka. The model was developed based on the empirical data on disposition of dioxins in fish tissues, as well as existing knowledge on the mechanisms of uptake, distribution, storage, and elimination of dioxins in various species (other than fish). The present study examined the applicability of mechanisms known to occur in other species for fish and concluded that the same mechanisms defined for disposition of 2,3,7,8-TCDD in (mostly) rodents can be applicable for the 2 fish species examined as well. Parameter values for the model were selected and/or calibrated using available databases. Model compartments included the gill, kidney, liver, and other richly-perfused tissues, as well as fat and other slowly-perfused tissues. The model was calibrated using 2 independent datasets for exposure of fathead minnow and medaka to 2,3,7,8-TCDD in water. The initial values of the model parameters were selected from several sources, and calibrated to represent the 2 exposure datasets. With very few exceptions, the estimated parameter values for the 2 species were comparable, and the final predictions were in strong agreement with the observations. The model developed in the present study can therefore be used in the prediction of the body burden of 2,3,7,8-TCDD in fathead minnow and medaka. Uncertainty in the model prediction as a result of variability in input parameters is discussed for the parameters with the highest impacts on the model outcome. PMID:24375498

  2. Paediatric male circumcision and penile hygiene: a Japanese mothers' view.

    PubMed

    Castro-Vázquez, Genaro

    2013-01-01

    This paper analyses the views of 20 Japanese mothers concerning paediatric male circumcision and penile hygiene. In Japan, routine male circumcision has never been implemented for newborns and children, and adult males are mostly circumcised at aesthetic clinics. However, media reports indicate a trend of Japanese mothers willing to have their sons circumcised. In discussing penile hygiene and male circumcision, the construct of a 'sexual script' becomes relevant to understanding how linguistic and gender barriers made references to male genitalia and penile hygiene largely appear as 'vulgar' and 'unfeminine' in daily life conversations. Peers were often identified as the main source of information and only mothers who have struggled with their children's penile infections have learnt about male genital hygiene, a domain of knowledge largely transmitted by men. Male circumcision becomes a double-edged sword that could help prevent penile infections but also an embarrassing conversational topic that could elicit discrimination because most Japanese children are uncircumcised. PMID:24152018

  3. Issei: Japanese Immigrants in Hawaii.

    ERIC Educational Resources Information Center

    Kimura, Yukiko

    Coming to Hawaii before July 1, 1924, when the Japanese Exclusion Act became effective, the experiences of the Issei or first generation are described. Divided into four parts, this book examines the experiences of Japanese immigrants in Hawaii from 1885 through 1970. Part 1, "The Formation and Stabilization of the Issei Community," explores the…

  4. The Japanese Language: An Introduction.

    ERIC Educational Resources Information Center

    Backhouse, A. E.

    This guide provides an overview of the salient features of the Japanese language from the perspective of the beginning-level English-speaking learner. Chapters address these topics: the Japanese language and its historic and cultural setting; phonology (sounds and syllables, word accentuation; loanwords; connected speech); writing (scripts,…

  5. Asian Pacific Perspectives: Japanese Americans.

    ERIC Educational Resources Information Center

    Los Angeles Unified School District, CA.

    These instructional materials on Japanese Americans for elementary students were developed through the K.E.Y.S. project (Knowledge of English Yields Success). Information is included on early immigrants, their historical and cultural background, and current problems of Japanese Americans. Resource guides describe the purpose of the unit, how to…

  6. A GLOSSARY OF JAPANESE NEOLOGISMS.

    ERIC Educational Resources Information Center

    BAILEY, DON C.

    THIS GLOSSARY COMPRISES A LIST OF USEFUL NEW WORDS AND PHRASES IN CURRENT USE NOT FOUND IN JAPANESE-ENGLISH DICTIONARIES, SPECIFICALLY KENKYUSHA'S NEW JAPANESE-ENGLISH DICTIONARY, 1954 EDITION, WHICH HAS SERVED AS THE MODEL IN MOST RESPECTS FOR THE FORMAT AND STYLE. ROMANIZATION OF THE ORTHOGRAPHY FOLLOWS A MODIFIED HEPBURN SYSTEM AND THE JAPANESE…

  7. Counseling Japanese Men on Fathering

    ERIC Educational Resources Information Center

    Seto, Atsuko; Becker, Kent W.; Akutsu, Motoko

    2006-01-01

    The authors review an article (J. Yamamoto & F. Tagami, 2004) published in the "Japanese Journal of Counseling Science" that described changes in contemporary Japanese family structures and illustrated a therapy process with a father to enhance the father-son relationship. Implications for the counseling profession in working with men on…

  8. Altered brain activity for phonological manipulation in dyslexic Japanese children

    PubMed Central

    Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

    2013-01-01

    Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children. PMID:24052613

  9. 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

  10. Reproductive and transgenerational toxicities of phenanthrene on female marine medaka (Oryzias melastigma).

    PubMed

    Sun, Lingbin; Zuo, Zhenghong; Chen, Meng; Chen, Yixin; Wang, Chonggang

    2015-05-01

    Phenanthrene (PHE) is one of the most abundant polycyclic aromatic hydrocarbons in the aquatic environment and often results from oil spills. To assess the effects of PHE on fish, marine medaka (Oryzias melastigma) was exposed to PHE at 0.06, 0.6, 6 and 60 μg/L. The reproductive functions and transgenerational effects were investigated. After 80 days exposure, the percentage of previtellogenic and vitellogenic oocytes in the ovary showed a significant decrease in the 0.06 and 60 μg/L groups. The mRNA levels of salmon-type gonadotropin releasing hormone, the follicle-stimulating hormone FSHβ, and the luteinizing hormone LHβ in the brain; the cytochrome P450 aromatase gene CYP19A and the estrogen receptor α (ERα) in the ovary; and ERα and vitellogenin VTG1 and 2 in the liver all exhibited significant down-regulation in the 0.06 and 60 μg/L groups, but did not significantly change in the 6 μg/L group compared to the control, which was quite consistent with development of the oocytes. A significant elevation of PHE accumulation in the brain in the 0.06 and 60 μg/L groups gave a reasonable explanation for the nonmonotonic dose-response and also elucidated the action pathway via the brain-pituitary-gonadal axis. The reduction of the time to hatch and the increased cardiac rhythm of embryos were in accord with the PHE accumulative levels in the eggs. The results demonstrated that exposure to PHE at both low and high concentrations can inhibit ovary development. In addition, PHE can be maternally transferred to embryos and influence the health and sustainability of the next generation. PMID:25805703

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

    PubMed

    Lee, Wenjau; Wang, Yun-Chi

    2015-01-01

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

  12. 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.

  13. Non Invasive High Resolution In Vivo Imaging of α-napthylisothiocyanate (ANIT) Induced Hepatobiliary Toxicity in STII Medaka

    PubMed Central

    Hardman, Ron; Kullman, Seth; Yuen, Bonny; Hinton, David E.

    2009-01-01

    A novel transparent stock of medaka (Oryzias latipes; STII), homozygous recessive for all four pigments (iridophores, xanthophores, leucophores, melanophores), permits transcutaneous, high resolution ( < 1μm) imaging of internal organs and tissues in living individuals. We applied this model to in vivo investigation of α-napthylisothiocyanate (ANIT) induced hepatobiliary toxicity. Distinct phenotypic responses to ANIT involving all aspects of intrahepatic biliary passageways (IHBPs), particularly bile preductular epithelial cells (BPDECs), associated with transitional passageways between canaliculi and bile ductules, were observed. Alterations included: attenuation/dilation of bile canaliculi, bile preductular lesions, hydropic vacuolation of hepatocytes and BPDECs, mild BPDEC hypertrophy, and biliary epithelial cell (BEC) hyperplasia. Ex vivo histological, immunohistochemical, and ultrastructural studies were employed to aid in interpretation of, and verify, in vivo findings. 3D reconstructions from in vivo investigations provided quantitative morphometric and volumetric evaluation of ANIT exposed and untreated livers. The findings presented show for the first time in vivo evaluation of toxicity in the STII medaka hepatobiliary system, and, in conjunction with prior in vivo work characterizing normalcy, advance our comparative understanding of this lower vertebrate hepatobiliary system and its response to toxic insult. PMID:18022256

  14. High levels of plasma cortisol and impaired hypoosmoregulation in a mutant medaka deficient in P450c17I.

    PubMed

    Takahashi, Hideya; Sato, Tadashi; Ikeuchi, Toshitaka; Saito, Kazuhiro; Sakaizumi, Mitsuru; Sakamoto, Tatsuya

    2016-07-15

    scl is a spontaneous medaka mutant deficient in P450c17I, which is required for production of sex steroids, but not of cortisol, the major role of which is osmoregulation in teleost fish. The scl mutant provides a new model to study the functions of these hormones. We first found that fish homozygous for this mutation have plasma cortisol constitutively at a high physiological level (1000 nM). Since we previously showed that this level reversed the seawater-type differentiation of the medaka gastrointestinal tract, hypoosmoregulation of the scl mutant was analyzed. Muscle water contents in freshwater were normal in scl homozygotes, but the contents were lower than those of the wild type (WT) after seawater transfer. There were no differences in gill mRNA levels of corticosteroid receptors or ion transporters between scl homozygotes and WT. In the intestine, expression of glucocorticoid receptors and Na(+)/K(+)/2Cl(-) cotransporter were induced in WT during seawater acclimation, but not in scl homozygotes. The high plasma cortisol may prevent hypoosmoregulation by inhibition of increased intestinal water absorption, essentially by the Na(+)/K(+)/2Cl(-) cotransporter, in seawater. PMID:27107936

  15. 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.

  16. Pathogenicity of the pinewood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings.

    PubMed

    Mamiya, Y; Shoji, T

    2009-06-01

    Pathogenicity of the pine wood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings was tested with inoculation experiments under nursery conditions. Water suspensions of nematodes (mixed stages cultured on Botrytis cinerea or dispersal fourth-stage juveniles (DJ4) extracted from the adult Japanese pine sawyer, Monochamus alternatus) were injected into the stems of 2- and 3-year-old Japanese larch and Japanese black pine, Pinus thunbergii, seedlings growing in a nursery. In another treatment, Japanese pine sawyer adults holding DJ4 were released under a net that covered the upper half of the seedlings. Regardless of nematode inoculation method, Japanese larch seedlings were as susceptible as Japanese black pine seedlings to B. xylophilus under nursery conditions. The rate of disease development was similar on larch and pine seedlings. Nematode population densities were lower in the stems of dead larch seedlings than in the stems of dead pine seedlings. Histopathological observations revealed that the distribution of nematodes in the stems of dead larch seedlings was mostly limited to the cortex, phloem and cambial zone. Traumatic resin canal formation was one of the most characteristic symptoms in larch seedlings which was dissimilar to that in pine seedlings. PMID:22661789

  17. Identification and Expression Profiling of MicroRNAs in the Brain, Liver and Gonads of Marine Medaka (Oryzias melastigma) and in Response to Hypoxia

    PubMed Central

    Lau, Karen; Lai, Keng Po; Bao, Jessie Yun Juan; Zhang, Na; Tse, Anna; Tong, Amy; Li, Jing Woei; Lok, Si; Kong, Richard Yuen Chong; Lui, Wing Yee; Wong, Alice; Wu, Rudolf Shiu Sun

    2014-01-01

    The marine medaka (Oryzias melastigma) has been increasingly used as a fish model for detecting environmental stresses and chemical contaminants in the marine environment. Recent mammalian studies have shown that environmental stresses can alter the expression profiles of microRNAs (miRNAs), leading to transgenerational effects. Here, we use high-throughput Illumina RNA sequencing (RNA-Seq) for miRNA transcriptome analysis of brain, liver, and gonads from sexually mature male and female marine medaka. A total of 128,883,806 filtered sequence reads were generated from six small RNA libraries, identifying a total of 2,125,663 non-redundant sequences. These sequences were aligned and annotated to known animal miRNAs (miRBase) using the BLAST method. A total of 223 distinct miRNA types were identified, with the greatest number expressed in brain tissue. Our data suggested that 55 miRNA types from 34 families are common to all tested tissues, while some of the miRNAs are tissue-enriched or sex-enriched. Quantitative real-time PCR analysis further demonstrated that let-7a, miR-122, and miR-9-3p were downregulated in hypoxic female medaka, while miR-2184 was specifically upregulated in the testis of hypoxic male fish. This is the first study to identify miRNAs in O. melastigma using small RNA deep sequencing technology. Because miRNA expression is highly conserved between marine medaka and other vertebrates, marine medaka may serve as a good model for studies on the functional roles of miRNAs in hypoxia stress response and signaling in marine fish. PMID:25350659

  18. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    SciTech Connect

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  19. Children's on-line processing of scrambling in Japanese.

    PubMed

    Suzuki, Takaaki

    2013-04-01

    This study investigates the on-line processing of scrambled sentences in Japanese by preschool children and adults using a combination of self-paced listening and speeded picture selection tasks. The effects of a filler-gap dependency, reversibility, and case markers were examined. The results show that both children and adults had difficulty in comprehending scrambled sentences when they were provided as reversible sentences. The reversibility effect was significant for children, whereas the interaction of reversibility and a filler-gap dependency was significant for adults. However, this does not indicate that children's parsing is fundamentally different from that of adults. For those children who processed the nominative and accusative case markers equally fast, the reactivation of the dislocated constituent was observed in the gap position. These results suggest that children's processing is basically the same as adults' in that their sentence processing is incremental and they parse a gap to form a filler-gap dependency. PMID:22460686

  20. Japanese viral encephalitis

    PubMed Central

    Tiroumourougane, S; Raghava, P; Srinivasan, S

    2002-01-01

    One of the leading causes of acute encephalopathy in children in the tropics is Japanese encephalitis (JE). Transmitted by the culex mosquito, this neurotropic virus predominately affects the thalamus, anterior horns of the spinal cord, cerebral cortex, and cerebellum. It mainly affects children <15 years and is mostly asymptomatic. The occasional symptomatic child typically presents with a neurological syndrome characterised by altered sensorium, seizures, and features of intracranial hypertension. Aetiological diagnosis is based on virus isolation or demonstration of virus specific antigen or antibodies in the cerebrospinal fluid/blood. Though no antiviral drug is available against JE, effective supportive management can improve the outcome. Control of JE involves efficient vector control and appropriate use of vaccines. PMID:11930023

  1. Japanese Experiment Module (JEM)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Japanese Experiment Module (JEM) pressure module is removed from its shipping crate and moved across the floor of the Space Station Processing Facility at Kennedy Space Center (KSC) to a work stand. A research laboratory, the pressurized module is the first element of the JEM, named 'Kibo' (Hope) to arrive at KSC. Japan's primary contribution to the International Space Station, the module will enhance unique research capabilities of the orbiting complex by providing an additional environment in which astronauts will conduct experiments. The JEM also includes an exposed facility or platform for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

  2. Japanese Encephalitis Vaccines

    PubMed Central

    McArthur, Monica A.; Holbrook, Michael R.

    2012-01-01

    Japanese encephalitis (JE) is a significant human health concern in Asia, Indonesia and parts of Australia with more than 3 billion people potentially at risk of infection with Japanese encephalitis virus (JEV), the causative agent of JE. Given the risk to human health and the theoretical potential for JEV use as a bioweapon, the development of safe and effective vaccines to prevent JEV infection is vital for preserving human health. The development of vaccines for JE began in the 1940s with formalin-inactivated mouse brain-derived vaccines. These vaccines have been shown to induce a protective immune response and to be very effective. Mouse brain-derived vaccines were still in use until May 2011 when the last lots of the BIKEN® JE-VAX® expired. Development of modern JE vaccines utilizes cell culture-derived viruses and improvements in manufacturing processes as well as removal of potential allergens or toxins have significantly improved vaccine safety. China has developed a live-attenuated vaccine that has proven to induce protective immunity following a single inoculation. In addition, a chimeric vaccine virus incorporating the prM and E structural proteins derived from the live-attenuated JE vaccine into the live-attenuated yellow fever 17D vaccine virus backbone is currently in clinical trials. In this article, we provide a summary of JE vaccine development and on-going clinical trials. We also discuss the potential risk of JEV as a bioweapon with a focus on virus sustainability if used as a weapon. PMID:23125946

  3. Photostimulation of Japanese quail.

    PubMed

    Molino, A B; Garcia, E A; Santos, G C; Vieira Filho, J A; Baldo, G A A; Almeida Paz, I C L

    2015-02-01

    To adapt commercial poultry production to a new scenario of energy savings and to develop specific practices for quail production aimed at reducing costs while maintaining or improving productivity, four experiments were conducted. In the first experiment, birds were allocated to four treatments (photoperiod duration): T1: 14 L:10 D; T2: 15 L:9 D; T3: 16 L:8 D; and T4: 17 L:7 D. In the second experiment, birds were subjected to four levels of brightness: T1: 5 lux; T2: 10 lux; T3:15 lux; and T4: 22 lux (control). In the third experiment, four types of lamps were evaluated: T1: compact fluorescent lamp (color temperature: 6,500 K); T2: compact fluorescent lamp (color temperature: 2,700 K); T3: incandescent lamp; and T4: yellow LED. In the last experiment, four lighting programs were compared: T1: continuous program (control), in which there was a single photoperiod of 15 h; the other treatments consisted of intermittent lighting programs, as follows: T2: 1 h of light provided 1 h after dusk; T3: 1 h of light provided 2 h before dawn; T4: half an hour of light provided 1 h after dusk and half an hour of light provided 1.5 h before dawn. In each experiment, 1,296 Japanese quail were evaluated for four 28-d cycles, totaling 112 experimental days. A completely randomized experimental design of 4 treatments with 12 replicates of 27 birds each was applied in all trials. Performance and egg quality were evaluated in each experiment. Higher egg production and adequate egg quality, as well as energy savings, can be obtained with Japanese quail using compact fluorescent lamps or LEDs and a photoperiod of 15 h/d supplied using an intermittent lighting program, with 1 h of artificial light 2 h before dawn at a brightness of 5 lux. PMID:25589080

  4. Japanese attitudes towards foreign languages.

    PubMed

    Abe, Keiko

    2004-01-01

    The purpose of this study is to clarify Japanese attitudes towards foreign languages based on the kinds and changes of TV and radio programs that aired on the Japanese national broadcasting station (NHK) between 1955 and 2000. Foreign language programs are classified into three groups according to their content: 1) cultivation, 2) education, or 3) communication. For Japanese people, foreign languages are the measures of intelligence and intellect. Studying a foreign language is considered a sign of intelligence whether or not it is used for actual communication. The number of foreign language programs has increased tremendously since 1965 in part because the global economy has brought many countries in such close contact. Since 1990, programs for the purpose of communication have increased because of the necessity to communicate with foreign people. Japanese attitudes towards studying foreign languages have been changing gradually from an intellectual purpose to a communication purpose. PMID:15156734

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

    PubMed Central

    2012-01-01

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

  6. Evolution of Acetylcholinesterase and Butyrylcholinesterase in the Vertebrates: An Atypical Butyrylcholinesterase from the Medaka Oryzias latipes

    PubMed Central

    Pezzementi, Leo; Nachon, Florian; Chatonnet, Arnaud

    2011-01-01

    Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are thought to be the result of a gene duplication event early in vertebrate evolution. To learn more about the evolution of these enzymes, we expressed in vitro, characterized, and modeled a recombinant cholinesterase (ChE) from a teleost, the medaka Oryzias latipes. In addition to AChE, O. latipes has a ChE that is different from either vertebrate AChE or BChE, which we are classifying as an atypical BChE, and which may resemble a transitional form between the two. Of the fourteen aromatic amino acids in the catalytic gorge of vertebrate AChE, ten are conserved in the atypical BChE of O. latipes; by contrast, only eight are conserved in vertebrate BChE. Notably, the atypical BChE has one phenylalanine in its acyl pocket, while AChE has two and BChE none. These substitutions could account for the intermediate nature of this atypical BChE. Molecular modeling supports this proposal. The atypical BChE hydrolyzes acetylthiocholine (ATCh) and propionylthiocholine (PTCh) preferentially but butyrylthiocholine (BTCh) to a considerable extent, which is different from the substrate specificity of AChE or BChE. The enzyme shows substrate inhibition with the two smaller substrates but not with the larger substrate BTCh. In comparison, AChE exhibits substrate inhibition, while BChE does not, but may instead show substrate activation. The atypical BChE from O. latipes also shows a mixed pattern of inhibition. It is effectively inhibited by physostigmine, typical of all ChEs. However, although the atypical BChE is efficiently inhibited by the BChE-specific inhibitor ethopropazine, it is not by another BChE inhibitor, iso-OMPA, nor by the AChE-specific inhibitor BW284c51. The atypical BChE is found as a glycophosphatidylinositol-anchored (GPI-anchored) amphiphilic dimer (G2a), which is unusual for any BChE. We classify the enzyme as an atypical BChE and discuss its implications for the evolution of AChE and BChE and for

  7. Japanese version of cutaneous body image scale: translation and validation.

    PubMed

    Higaki, Yuko; Watanabe, Ikuko; Masaki, Tomoko; Kamo, Toshiko; Kawashima, Makoto; Satoh, Toshihiko; Saitoh, Shiroh; Nohara, Michiko; Gupta, Madhulika A

    2009-09-01

    Cutaneous body image, defined as the individual's mental perception of the appearance of their skin, hair and nails, is an important psychodermatological element in skin diseases. To measure individuals' cutaneous body image, a practical and accurate instrument is necessary. In this study, we translated the Cutaneous Body Image Scale (CBIS), a 7-item instrument originally created by Gupta et al. in 2004, into Japanese using a forward- and back-translation method and evaluated the reliability and validity of the instrument by psychometric tests. A total of 298 healthy adults (64 men and 234 women, aged 28.9 +/- 9.9 years) and 165 dermatology patients (56.7% eczema/dermatitis, 9.8% acne, 7.5% alopecia, 6.9% psoriasis, 19.1% skin tumor/fleck/other) (30 men and 135 women, aged 37.9 +/- 15.2 years) responded to the Japanese version of the CBIS. The internal-consistency reliability of the instrument was high (Cronbach's alpha, healthy adults 0.88, patients 0.84). The CBIS measure demonstrates good test-retest reliability (healthy adults gamma = 0.92, P < 0.0001; patients gamma = 0.79, P < 0.001). Compared to the healthy adults (4.11 +/- 1.80), the CBIS scores among dermatology patients (3.18 +/- 1.69, P = 0.000) were significantly low. The CBIS scores showed moderate correlation with the "emotions" and "global" scores of Skindex-16 in healthy adults (gamma = -0.397 and -0.373, respectively) and in patients (gamma = -0.431 and -0.38, respectively). A stepwise multiple regression analysis revealed that an emotional aspect of skin-condition related quality of life was the best predictor of cutaneous body image in both healthy adults and patients (beta = -0.31 and -0.41, respectively) followed by "body dissatisfaction" (beta = -0.17, and -0.23, respectively). Adjusted R(2) was 0.246 in healthy adults and 0.264 in patients. These were consistent with the results from the original the CBIS. These results suggest that the Japanese version of the CBIS is a reliable and valid

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

    PubMed

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

    2014-01-01

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

  9. The Japanese Balloon Program

    NASA Astrophysics Data System (ADS)

    Nishimura, J.

    The Japanese scientific ballooning program has been organized by ISAS since the institute was founded in mid 1960s. Since then, the balloon group of ISAS has been engaged in the development of the balloon technologies and scientific observations in collaboration with scientists and engineers in other universities and organizations. Here, I describe several subjects of recent activities, the details of some items will also be reported in the separate papers in this meeting.Preparation of a new mobile receiving station.

  10. Balloons of made of the EVAL (Ethylene-Vinyl-Alcohol) films. EVAL film has specific Infra-red absorption bands, and is expected to be useful for saving the ballast for a long duration flight.
  11. A high altitude balloon with thin polyethylene films achieving at an altitude of above 50km. Further improvement of this type of balloons is continued by inventing how to extrude thin films less than 5 microns of thickness.
  12. Recent achievement of Antarctica Flights under the collaboration of ISAS and National Polar Institute.
  13. Other new efforts to long duration flights such as satellite link boomerang balloon systems and others.
  14. New balloon borne scientific instrumentation for observations of high energy electrons and Anti-protons in cosmic-rays.
  15. Accessibility of host cell lineages to medaka stem cells depends on genetic background and irradiation of recipient embryos.

    PubMed

    Hong, Ni; Li, Mingyou; Zeng, Zhiqiang; Yi, Meisheng; Deng, Jiaorong; Gui, Jianfang; Winkler, Christoph; Schartl, Manfred; Hong, Yunhan

    2010-04-01

    Chimera formation is a powerful tool for analyzing pluripotency in vivo. It has been widely accepted that host cell lineages are generally accessible to embryonic stem (ES) cells with the actual contribution depending solely on the intrinsic pluripotency of transplanted donor cells. Here, we show in the fish medaka (Oryzias latipes) that the host accessibility to ES cell contribution exhibits dramatic differences. Specifically, of three albino host strains tested (i (1) , i (3) and af), only strain i (1) generated pigmented chimeras. Strikingly, this accessibility is completely lost in i (1) but acquired in i (3) after host gamma-irradiation. Host irradiation also differentially affected ES cell contribution to somatic organs and gonad. Therefore, the accessibility of various host cell lineages can vary considerably depending on host strains and cell lineages as well as on irradiation. Our findings underscore the importance of host genotypes for interpreting donor cell pluripotency and for improving ES-derived chimera production. PMID:20238480

  16. Autobiographical memory functions in young Japanese men and women.

    PubMed

    Maki, Yoichi; Kawasaki, Yayoi; Demiray, Burcu; Janssen, Steve M J

    2015-01-01

    The present study examined whether the three major functions of autobiographical memory observed in Western societies (i.e., directing-behaviour, social-bonding and self-continuity) also exist in an East Asian society. Two self-report measures were used to assess the autobiographical memory functions of Japanese men and women. Japanese young adults (N = 451, ages 17-28 years) first completed the original Thinking About Life Experiences (TALE) Questionnaire. They subsequently received three TALE items that represented memory functions and attempted to recall a specific instance of memory recall for each item. Confirmatory factor analyses on the TALE showed that the three functions were replicated in the current sample. However, Japanese participants reported lower levels of all three functions than American participants in a previous study. We also explored whether there was an effect of gender in this Japanese sample. Women reported higher levels of the self-continuity and social-bonding functions than men. Finally, participants recalled more specific instances of memory recall for the TALE items that had received higher ratings on the TALE, suggesting that the findings on the first measure were supported by the second measure. Results are discussed in relation to the functional approach to autobiographical memory in a cross-cultural context. PMID:24967887

  17. 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. PMID:26924701

  18. Color constancy in Japanese animation

    NASA Astrophysics Data System (ADS)

    Ichihara, Yasuyo G.

    2006-01-01

    In this study, we measure the colors used in a Japanese Animations. The result can be seen on CIE-xy color spaces. It clearly shows that the color system is not a natural appearance system but an imagined and artistic appearance system. Color constancy of human vision can tell the difference in skin and hair colors between under moonlight and day light. Human brain generates a match to the memorized color of an object from daylight viewing conditions to the color of the object in different viewing conditions. For example, Japanese people always perceive the color of the Rising Sun in the Japanese flag as red even in a different viewing condition such as under moonlight. Color images captured by a camera cannot present those human perceptions. However, Japanese colorists in Animation succeeded in painting the effects of color constancy not only under moonlight but also added the memory matching colors. They aim to create a greater impact on viewer's perceptions by using the effect of the memory matching colors. In this paper, we propose the Imagined Japanese Animation Color System. This system in art is currently a subject of research in Japan. Its importance is that it could also provide an explanation on how human brain perceives the same color under different viewing conditions.

  19. In vivo recombination efficiency of two site-specific recombination systems, VCre/VloxP and SCre/SloxP, in medaka (Oryzias latipes).

    PubMed

    Kishimoto, Kenta; Nakayama, Manabu; Kinoshita, Masato

    2016-08-01

    The present study delineates the in vivo efficiency of two site-specific recombination systems, VCre/VloxP and SCre/SloxP, in medaka (Oryzias latipes). VCre, SCre, and Cre RNA was microinjected into fertilized medaka eggs belonging to three transgenic lines harboring VloxP, SloxP, and loxP cassette. VCre induced site-specific recombination specifically at VloxP sequence and SCre at SloxP sequence without any cross-reactivity. These findings provide two novel alternative recombination systems in vivo in addition to the existing Cre/loxP and Flp/FRT systems, thus enabling sophisticated gene expression in model organisms. PMID:27224047

  20. 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...

  21. An Assessment of the Effects of the Endocrine Disrupting Chemical 17ß-Trenbolone on Japanese Medaka Fish in a Multigenerational Exposure

    EPA Science Inventory

    Presently the research emphasis for endocrine disrupting chemicals has been on the development of short-term screening assays. However, assessing effect concentrations of the most sensitive developmental stages impacted in longer-term and multi-generation tests remains to be det...

  22. An Evaluation of the Chronic Effects of Endocrine Disrupting Chemical 4-tert-octylphenol using Japanese Medaka in a Multigenerational Test

    EPA Science Inventory

    The USEPA seeks to assess the potential effects of chemicals on populations of fish. For many of these chemicals there is little information regarding their potential to produce effects on reproduction and reproductive development through two full generations. To facilitate and...

  23. Japanese respond to campaign.

    PubMed

    1994-08-01

    A unique campaign launched by JOICFP in August 1993 had by the end of June 1994 netted US $41,200 to support activities of the integrated Project (IP) in developing countries. Under the campaign, the public, institutions, organizations, and businesses have been sending in used prepaid cards for sale to collectors in Japan and abroad. Prepaid cards are widely used throughout Japan for phones, subways, railways and highways. Nippon Telegraph and Telephone Corporation (NTT) alone issues 20 million cards annually. The campaign, which has been widely featured in the media, has proved effective for drawing attention to JOICFP and to population and family planning issues. Gaining the understanding of the Japanese public about population issues has grown in importance since the government's announcement of the new Global Issues Initiative (GII). Word about the campaign was carried by radio, television, newspapers, and magazines nationwide. The number of cards sent in escalated with the attention. By the end of June, JOICFP had received around 700,000 cards, of which 550,000 have been exchanged for cash. The funds generated by the card sales have been allocated to support grassroots IP activities and encourage the self-reliance of projects in China, Ghana, Guatemala, Nepal, Tanzania, and Zambia. Responses to the campaign have come from individuals as well as local governments, hospitals, enterprises, and educational institutions. Many of these have initiated their own card-collection system and information-dissemination activities to support JOICFP. Over 5000 different organizations are now collaborating with JOICFP for the campaign, including Tenmaya Department Store in Okayama City. PMID:12288124

  24. Homogamy and Intermarriage of Japanese and Japanese Americans with Whites Surrounding World War II

    ERIC Educational Resources Information Center

    Ono, Hiromi; Berg, Justin

    2010-01-01

    Although some sociologists have suggested that Japanese Americans quickly assimilated into mainstream America, scholars of Japanese America have highlighted the heightened exclusion that the group experienced. This study tracked historical shifts in the exclusion level of Japanese and Japanese Americans in the United States surrounding World War…

  25. Construction of a Linkage Map of the Medaka (Oryzias latipes) and Mapping of the Da Mutant Locus Defective in Dorsoventral Patterning

    PubMed Central

    Ohtsuka, Masato; Makino, Satoshi; Yoda, Kinya; Wada, Hironori; Naruse, Kiyoshi; Mitani, Hiroshi; Shima, Akihiro; Ozato, Kenjiro; Kimura, Minoru; Inoko, Hidetoshi

    1999-01-01

    Double anal fin (Da) is a medaka with an autosomal semidominant mutation that causes mirror image duplication of the ventral region concentrating on the caudal region. The chromosomal location of the Da gene and its sequence have remained unknown. We constructed a medaka linkage map as a first step to approach positional cloning of the gene. The segregation analysis was performed on the basis of genetic recombination during female meiosis using 134 random amplified polymorphic DNA (RAPD) markers, 13 sequence-tagged sites (STSs), 15 polymorphic sequences from known genes, and the Da gene. One hundred forty-six markers from the above markers segregated into 26 linkage groups. The size of the genome was estimated to be 1776 cM in length. We identified four syntenic regions between medaka and zebrafish (and human) by mapping the known genes and found one of them to be located in close proximity to the Da gene. By mapping the region surrounding the Da gene in high resolution, two markers were detected flanking the Da gene at 0.32 and 0.80 cM. The detected markers providing a vital clue to initiate chromosome walking will lead us to the definite location of the Da gene. PMID:10613850

  1. Marine Biodiversity in Japanese Waters

    PubMed Central

    Fujikura, Katsunori; Lindsay, Dhugal; Kitazato, Hiroshi; Nishida, Shuhei; Shirayama, Yoshihisa

    2010-01-01

    To understand marine biodiversity in Japanese waters, we have compiled information on the marine biota in Japanese waters, including the number of described species (species richness), the history of marine biology research in Japan, the state of knowledge, the number of endemic species, the number of identified but undescribed species, the number of known introduced species, and the number of taxonomic experts and identification guides, with consideration of the general ocean environmental background, such as the physical and geological settings. A total of 33,629 species have been reported to occur in Japanese waters. The state of knowledge was extremely variable, with taxa containing many inconspicuous, smaller species tending to be less well known. The total number of identified but undescribed species was at least 121,913. The total number of described species combined with the number of identified but undescribed species reached 155,542. This is the best estimate of the total number of species in Japanese waters and indicates that more than 70% of Japan's marine biodiversity remains un-described. The number of species reported as introduced into Japanese waters was 39. This is the first attempt to estimate species richness for all marine species in Japanese waters. Although its marine biota can be considered relatively well known, at least within the Asian-Pacific region, considering the vast number of different marine environments such as coral reefs, ocean trenches, ice-bound waters, methane seeps, and hydrothermal vents, much work remains to be done. We expect global change to have a tremendous impact on marine biodiversity and ecosystems. Japan is in a particularly suitable geographic situation and has a lot of facilities for conducting marine science research. Japan has an important responsibility to contribute to our understanding of life in the oceans. PMID:20689840

  2. JABEE in Japanese Engineering Education

    NASA Astrophysics Data System (ADS)

    Takeda, Kunihiko; Ishikawa, Tomoyuki

    JABEE in Japanese engineering education is discussed by focusing on the status and treatment of engineers in Japanese society and their achievements. The entrance fee and tuition of the engineering departments of higher education facilities are higher than those of the law, economy and literature departments. On the other hand, an engineer's lifelong wage is smaller than that of those who have graduated from the latter fields. Although engineering students must study for a longer period of time, the scholarship system to support these students in Japan falls far behind that in the U.S.A. The achievements of Japanese engineering were summarized from the viewpoint of economic indications such as 1) production of steel, 2) energy consumption per person as a function of GDP, 3) income 4) real estate abroad and miscellaneous factors such as the life spans and criminal rates of many countries. These analyses made it clear that Japanese engineers have the highest ability even compared to advanced countries and this is because of the higher engineering education in Japan ; but their status is unreasonably low in Japanese society. The four points by which the present status of Japanese engineers can be improved were discussed in relation to the introduction and the achievement of the JABEE system. The true aim of education reform by JABEE is that the engineering education in Japan should shift “from government to non-government”, “from organization to individual” and “from control to interdependency.” The expected points of improvement are discussed.

  3. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    PubMed Central

    Webb, Carol F.; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-01-01

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. PMID:26111446

  4. The Nonacademic Curriculum of the Japanese Preschool.

    ERIC Educational Resources Information Center

    Peach, Mark

    1994-01-01

    Japanese nursery school and kindergarten activities are designed to facilitate the socialization of Japanese children. The culture of the home and the culture of the school (and by extension the rest of Japanese society) are so different from each other that it is believed the open and unselfconscious help of the education system is necessary to…

  5. Shattering Myths: Japanese American Educational Issues.

    ERIC Educational Resources Information Center

    Yoshiwara, Florence M.

    An historical review of the immigration and resettlement patterns, and a demographic profile of Japanese Americans reveals a myth of the "successful minority." Since the founding of the Japanese American Citizens League in 1928, Japanese Americans have defeated alien land laws, discriminatory immigration quotas, anti-miscengenation laws, and…

  6. Two Modes of Counting in Japanese.

    ERIC Educational Resources Information Center

    Backus, Robert L.

    1972-01-01

    This paper seeks to formulate a principle that explains the working of the Japanese number system with respect to Japanese nouns and that defines the kinds of nouns and contexts that condition the forms of number expressions. It is the author's theory that in applying numbers to nouns, the Japanese make a formal distinction between things they…

  7. Teaching Japanese Literature and Translation in Tandem.

    ERIC Educational Resources Information Center

    Beichman, Janine

    1983-01-01

    Describes a method of teaching Japanese literature to Japanese native speakers by comparing English translations to the original texts. Discusses criteria for choosing a text and lists some of the texts used and the method in which they were used. This method gave students a deeper understanding of the original Japanese text. (SED)

  8. Japanese/Korean Linguistics, Volume 8.

    ERIC Educational Resources Information Center

    Silva, David J., Ed.

    A collection of research in Japanese and Korean linguistics includes: "Repetition, Reformulation, and Definitions: Prosodic Indexes of Elaboration in Japanese" (Mieko Banno); "Projection of Talk Using Language, Intonation, Deictic and Iconic Gestures and Other Body Movements" (Keiko Emmett); "Turn-taking in Japanese Political Debate: Syntax,…

  9. Development of the Japanese Sword

    NASA Astrophysics Data System (ADS)

    Tanimura, Hiromu

    1980-02-01

    Both the beauty and the utility of the Japanese sword as a weapon depend on the characteristic metallic component structure of the sword blade steel. After briefly describing the characteristics of the sword blade and the history of the Japanese sword, this paper describes the forging process for making the composite structure of the sword blade steel, according to the author's experiences. Finally, andent ironmaking and steelmaking processes are briefly explained. The author concludes that the high purity of the iron and steel obtained to the beauty and artistry of the finished sword blade.

  10. Other Japanese Educations and Japanese Education Otherwise. Review Essay

    ERIC Educational Resources Information Center

    Takayama, Keita

    2011-01-01

    Education in the United States was in a state of "crisis" at the time of the 1983 release of "A Nation at Risk," the landmark report on the US education reform. This was the time when the rising Japanese economy started threatening the post-war US economic dominance and conservative figures such as Ronald Reagan gained popular support. Subsequent…

  11. Japanese couples' opinions.

    PubMed

    Ozaki, M

    1993-06-01

    The Japanese National Survey on Family Planning has been conducted since 1950 by the Mainichi Newspapers. The 21st survey, which included approximately 3400 persons, was conducted in 1992 in conjunction with various family planning organizations. The results reported include the ideal number of children, care for the elderly, tolerance for induced abortion, beliefs about the side effects of oral contraceptives, attitudes of husbands toward their wives working outside the home, sexual harassment, and elderly husband's concern about contracting AIDS. 45% of respondents supported Japan's involvement in FP efforts in developing countries, and 20.9% disapproved of involvement. Fertility declined from 1.54 in 1990 to 1.53 in 1991. There was an 5% increase to 75.3% in the number of women concerned about declining fertility for such reasons as the loss of social vitality and the increased burden of support in old age. However, 60.9% of wives and 56.8% of husbands felt that the government should not take action to prevent further fertility decline. Public policies for reducing the cost of education were supported by 39.6% of wives and 43.6% of husbands. A similar number supported increases in child allowance, and a smaller percentage of husbands and wives wanted the government to subsidize housing expenses. The ideal number of children was 3 for 45.7% of those surveyed, which was more than those desiring 2 children. The ideal of 3 children was held by survey participants who were more than 35 years old and by those with a high education. Part-time workers and office clerks were more likely to report that 2 children were ideal. An increasing number of respondents (60.4%) do not intend to rely on their children in old age. There has been a shift in family planning methods from induced abortions to increased contraceptive use. The highest rate of contraceptive use is among wives 35-39 years old. 75.3% use condoms. 67.7% reported concern about side effects from oral

  12. Perception of a Japanese Vowel Length Contrast by Japanese and American English listeners: Behavioral and Electrophysiological Measures

    PubMed Central

    Hisagi, Miwako; Shafer, Valerie L.; Strange, Winifred; Sussman, Elyse S.

    2010-01-01

    This study examined the role of automatic selective perceptual processes in native and non-native listeners' perception of a Japanese vowel length contrast (tado vs. taado), using multiple, natural-speech tokens of each category as stimuli in a “categorial oddball” design. Mismatch Negativity (MMN) was used to index discrimination of the temporally-cued vowel contrast by naïve adult American listeners and by a native Japanese-speaking control group in two experiments in which attention to the auditory input was manipulated: in Exp 1 (Visual-Attend), listeners silently counted deviants in a simultaneously-presented visual categorial oddball shape discrimination task; in Exp 2 (Auditory-Attend), listeners attended to the auditory input and implicitly counted target deviants. MMN results showed effects of language experience and attentional focus: MMN amplitudes were smaller for American compared to Japanese listeners in the Visual-Attend Condition and for the American listeners in the Visual compared to Auditory-Attend condition. Subtle differences in topography were also seen, specifically in that the Japanese group showed more robust responses than the American listener's at left hemisphere scalp sites that probably index activity from the superior temporal gyrus. Follow-up behavioral discrimination tests showed that Americans discriminated the contrast well above chance, but more poorly than did Japanese listeners. This pattern of electrophysiological and behavioral results supports the conclusion that early experience with phonetic contrasts of a language results in changes in neural representations in auditory cortex that allow for more robust automatic, phonetic processing of native-language speech input. PMID:20816759

  13. Gender-specific modulation of immune system complement gene expression in marine medaka Oryzias melastigma following dietary exposure of BDE-47.

    PubMed

    Ye, Roy R; Lei, Elva N Y; Lam, Michael H W; Chan, Alice K Y; Bo, Jun; van de Merwe, Jason P; Fong, Amy C C; Yang, Michael M S; Lee, J S; Segner, Helmut E; Wong, Chris K C; Wu, Rudolf S S; Au, Doris W T

    2011-08-01

    BDE-47 is one of the most widely found congeners of PBDEs in marine environments. The potential immunomodulatory effects of BDE-47 on fish complement system were studied using the marine medaka Oryzias melastigma as a model fish. Three-month-old O. melastigma were subjected to short-term (5 days) and long-term (21 days) exposure to two concentrations of BDE-47 (low dose at 290 ± 172 ng/day; high dose at 580 ± 344 ng/day) via dietary uptake of BDE-47 encapsulated in Artemia nauplii. Body burdens of BDE-47 and other metabolic products were analyzed in the exposed and control fish. Only a small amount of debrominated product, BDE-28, was detected, while other metabolic products were all under detection limit. Transcriptional expression of six major complement system genes involved in complement activation: C1r/s (classical pathway), MBL-2 (lectin pathway), CFP (alternative pathway), F2 (coagulation pathway), C3 (the central component of complement system), and C9 (cell lysis) were quantified in the liver of marine medaka. Endogenous expression of all six complement system genes was found to be higher in males than in females (p < 0.05). Upon dietary exposure of marine medaka to BDE-47, expression of all six complement genes were downregulated in males at day 5 (or longer), whereas in females, MBl-2, CFP, and F2 mRNAs expression were upregulated, but C3 and C9 remained stable with exposure time and dose. A significant negative relationship was found between BDE-47 body burden and mRNA expression of C1r/s, CFP, and C3 in male fish (r = -0.8576 to -0.9447). The above findings on changes in complement gene expression patterns indicate the complement system may be compromised in male O. melastigma upon dietary exposure to BDE-47. Distinct gender difference in expression of six major complement system genes was evident in marine medaka under resting condition and dietary BDE-47 challenge. The immunomodulatory effects of BDE-47 on transcriptional

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

    PubMed

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

    2016-01-01

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

  15. Teaching Japanese-American Incarceration

    ERIC Educational Resources Information Center

    Miksch, Karen L.; Ghere, David

    2004-01-01

    Few events in American history are so universally deplored as the incarceration of Japanese Americans during World War II. The United States government has acknowledged the error and the injustice that resulted with an official Presidential apology and a Congressional disbursement of reparations to the victims of the incarceration policy. The…

  16. The Japanese Copula: A Dummy?

    ERIC Educational Resources Information Center

    Wenck, G.

    1973-01-01

    Discussion of whether the Japanese copula can adequately be described as a dummy, i.e., as an element which although existing in the surface structure can be dispensed with in the deep structure of a sentence; based on a paper read at the 1970 meeting of the Societas Linguistica Europaea, Prague, Czechoslovakia. (RS)

  17. Japanese Industry Boosts Pollution Spending

    ERIC Educational Resources Information Center

    McAbee, Michael K.

    1975-01-01

    In response to tightening emission standards imposed by the government, Japanese industry will increase its capital spending on pollution control equipment to account for about 20 percent of all industrial capital spending. Preferential treatment and loans from government-affiliated financial institutions are available for projects. (Author/MLH)

  18. Contrastive Rhetoric: Japanese and English.

    ERIC Educational Resources Information Center

    Hinds, John

    Research is reviewed on systematic differences in expository styles due to cultural or linguistic diversity. The critique concentrates on the method of data gathering, the usage of the categorization "Oriental," and the description of English paragraph development. An investigation is reported that consisted of an analysis of the Japanese and…

  19. Japanese Logic Puzzles and Proof

    ERIC Educational Resources Information Center

    Wanko, Jeffrey J.

    2009-01-01

    An understanding of proof does not start in a high school geometry course. Rather, attention to logical reasoning throughout a student's school experience can help the development of proof readiness. In the spirit of problem solving, the author has begun to use some Japanese logic puzzles other than sudoku to help students develop additional…

  20. Japanese at Mimosa Elementary School.

    ERIC Educational Resources Information Center

    Uchihara, Azusa

    2001-01-01

    Describes the Japanese program at Mimosa Elementary School in Roswell, Georgia. The success of the program has been aided by collaborative team teaching, a spiraled curriculum, creative teaching methods, Teacher -made materials, and communication among teachers, parents, and administrators. he challenges are also discussed. (Author/VWL)

  1. An Island Effect in Japanese.

    ERIC Educational Resources Information Center

    Richards, Norvin

    2000-01-01

    Develops an argument for a pied-piping approach to the apparent absence of island effects in Japanese, along the lines of Nishigauchi (1986, 1990). Investigates the nature of pied-piping, developing a theory that accounts for the fact that wh-islands cannot be pied-piped. (Author/VWL)

  2. Three Plays from the Japanese.

    ERIC Educational Resources Information Center

    Mayfield, M. Kent

    This study is both an interpretation and a translation of three modern Japanese plays, providing an artistic perspective on the radical reordering of experience and thought with which modern man must grapple in cross-cultural encounters. An introductory essay prefaces each play, providing a historical, critical, or appreciative perspective from…

  3. Citation Indicators of Japanese Journals.

    ERIC Educational Resources Information Center

    Haiqi, Zhang; Yamazaki, Shigeaki

    1998-01-01

    Evaluates Japanese journals--128 indexed in the 1994 "Journal Citation Reports"--in bibliometric parameters such as impact factors (IFs), mean IFs from citing and cited journals, and self-citing and self-cited rates. Results: only 15 journals, with a wide variation of self-citing and self-cited rates, have obtained a current impact higher than…

  4. Moral Development of Japanese Kindergartners.

    ERIC Educational Resources Information Center

    Taylor, Satomi Izumi; Ogawa, Tetsuya; Wilson, Jeanne

    2002-01-01

    Interviews were conducted with 28 kindergartners, their teachers, and their director to examine Japanese children's moral development. Qualitative analysis of interviews revealed three themes related to moral development: social system morality, emotions, and responsibility. Children made moral decisions based on social system morality…

  5. Japanese; Particles, Verbs, and Adjectives.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This volume has been prepared as a reference book on particles, verbs, and "true" adjectives, as presented in the Defense Language Institute's Basic Course in Japanese. Forty-six particles are listed, with varying numbers of different usages explained and illustrated by examples. (AMM)

  6. Long Distance Scrambling in Japanese.

    ERIC Educational Resources Information Center

    Saito, Mamoru

    1992-01-01

    The nature of scrambling in Japanese is examined in light of the work of Webelhuth and Mahajan, and it is argued that their apparently inconsistent hypotheses are both necessary for the analysis of scrambling. A modified version is suggested. (59 references) (Author/LB)

  7. Acquisition and Use of Linguistic Knowledge: Scrambling in Child Japanese as a Test Case

    ERIC Educational Resources Information Center

    Minai, Utako; Isobe, Miwa; Okabe, Reiko

    2015-01-01

    The current study investigates preschool-age children's comprehension of scrambled sentences in Japanese. While scrambling has been known to be challenging for children, biasing them to exhibit non-adult-like interpretations (e.g., Hayashibe in "Descr Appl Linguist" 8:1-18, 1975; Sano in "Descr Appl Linguist" 10:213-233, 1977;…

  8. Is "g" an Entity? A Japanese Twin Study Using Syllogisms and Intelligence Tests

    ERIC Educational Resources Information Center

    Shikishima, Chizuru; Hiraishi, Kai; Yamagata, Shinji; Sugimoto, Yutaro; Takemura, Ryo; Ozaki, Koken; Okada, Mitsuhiro; Toda, Tatsushi; Ando, Juko

    2009-01-01

    Using a behavioral genetic approach, we examined the validity of the hypothesis concerning the singularity of human general intelligence, the "g" theory, by analyzing data from two tests: the first consisted of 100 syllogism problems and the second a full-scale intelligence test. The participants were 448 Japanese young adult twins (167 pairs of…

  9. Influence of sexual competition and social context on homosexual behavior in adolescent female Japanese macaques.

    PubMed

    Gunst, Noëlle; Leca, Jean-Baptiste; Vasey, Paul L

    2015-05-01

    We explored the role that sexual and social partners play in the expression of female homosexual behavior among adolescent female Japanese macaques at Arashiyama, Japan. Our data fully or partially supported all the predictions related to four non-mutually exclusive hypotheses, namely the "adult male disinterest in adolescent females" hypothesis, the "numerous homosexual adult females" hypothesis, the "safer homosexual interactions" hypothesis and the "same-sex sexual interactions" hypothesis. Our results show that both sexual context (e.g., lack of adolescent female attractivity toward adult males, presence of motivated same-sex sexual partners), and social context (e.g., risk of aggression) help explain the high frequency and prevalence of homosexual behavior in adolescent females in the Arashiyama group of Japanese macaques. As with adult females, whose homosexual consortships do not reflect generalized patterns of social affiliation or kinship, we found that adolescent females' same-sex sexual partners were neither kin, nor were they non-kin individuals with whom adolescent females were closely affiliated outside of a consortship context. Our study furthers the growing database of female homosexual behavior in Japanese macaques and provides additional evidence that homosexual behavior as expressed by adolescent female Japanese macaques is, like heterosexual behavior, sexual in nature. We discuss the relevance of our findings to a broader comparative approach that may shed light upon the development and evolution of human homosexuality. PMID:25597406

  10. A Comparative Study of Japanese/English Bilingual Code-Switching in Three Different Domains.

    ERIC Educational Resources Information Center

    Taura, Hideyuki

    This study examined Japanese/English code-switching in three different contexts: a bilingual radio program broadcast in Japan; language of two bilingual siblings; and an adult bilingual dinner party. Particular attention was paid to the situational meanings of code-switching and to politeness issues. Code-switching was examined first at four…

  11. Extensive Reading and Language Learning: A Diary Study of a Beginning Learner of Japanese.

    ERIC Educational Resources Information Center

    Leung, Ching Yin

    2002-01-01

    Investigated the impact of extensive reading on an adult's self-study of Japanese over a 20-week period. Data were collected from a learner diary, audio recordings from several private tutorial sessions, and vocabulary tests. Results show extensive reading can enhance vocabulary acquisition and reading comprehension and promote a positive attitude…

  12. Japanese and American Children's Moral Evaluations of Reporting on Transgressions

    ERIC Educational Resources Information Center

    Chiu Loke, Ivy; Heyman, Gail D.; Itakura, Shoji; Toriyama, Rie; Lee, Kang

    2014-01-01

    American and Japanese children's evaluations of the reporting of peers' transgressions to authority figures were investigated. Seven-, 9-, and 11-year-old children (N = 160) and adults (N = 62) were presented with vignettes and were asked to evaluate the decisions of child observers who reported their friend's either major or…

  13. Pair-List Readings in Korean-Japanese, Chinese-Japanese and English-Japanese Interlanguage

    ERIC Educational Resources Information Center

    Marsden, Heather

    2008-01-01

    In English and Chinese, questions with a "wh"-object and a universally quantified subject (e.g. "What did everyone buy?") allow an individual answer ("Everyone bought apples.") and a pair-list answer ("Sam bought apples, Jo bought bananas, Sally bought..."). By contrast, the pair-list answer is reportedly unavailable in Japanese and Korean. This…

  14. 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

  15. Contrast and covert contrast: The phonetic development of voiceless sibilant fricatives in English and Japanese toddlers

    PubMed Central

    Li, Fangfang; Edwards, Jan; Beckman, Mary E.

    2009-01-01

    This paper examines the acoustic characteristics of voiceless sibilant fricatives in English-and Japanese-speaking adults and the acquisition of contrasts involving these sounds in 2- and 3-year-old children. Both English and Japanese have a two-way contrast between an alveolar fricative (/s/), and a postalveolar fricative (/∫/ in English and /ɕ/ in Japanese). Acoustic analysis of the adult productions revealed cross-linguistic differences in what acoustic parameters were used to differentiate the two fricatives in the two languages and in how well the two fricatives were differentiated by the acoustic parameters that were investigated. For the children’s data, the transcription results showed that English-speaking children generally produced the alveolar fricative more accurately than the postalveolar one, whereas the opposite was true for Japanese-speaking children. In addition, acoustic analysis revealed the presence of covert contrast in the productions of some English-speaking and some Japanese-speaking children. The different development patterns are discussed in terms of the differences in the fine phonetic detail of the contrast in the two languages. PMID:19672472

  16. Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) - Mammalian Mutagenicity Study Group (MMS).

    PubMed

    Hamada, Shuichi; Ohyama, Wakako; Takashima, Rie; Shimada, Keisuke; Matsumoto, Kazumi; Kawakami, Satoru; Uno, Fuyumi; Sui, Hajime; Shimada, Yasushi; Imamura, Tadashi; Matsumura, Shoji; Sanada, Hisakazu; Inoue, Kenji; Muto, Shigeharu; Ogawa, Izumi; Hayashi, Aya; Takayanagi, Tomomi; Ogiwara, Yosuke; Maeda, Akihisa; Okada, Emiko; Terashima, Yukari; Takasawa, Hironao; Narumi, Kazunori; Wako, Yumi; Kawasako, Kazufumi; Sano, Masaki; Ohashi, Nobuyuki; Morita, Takeshi; Kojima, Hajime; Honma, Masamitsu; Hayashi, Makoto

    2015-03-01

    The repeated-dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect hepatocarcinogens. We conducted a collaborative study to assess the performance of this assay and to evaluate the possibility of integrating it into general toxicological studies. Twenty-four testing laboratories belonging to the Mammalian Mutagenicity Study Group, a subgroup of the Japanese Environmental Mutagen Society, participated in this trial. Twenty-two model chemicals, including some hepatocarcinogens, were tested in 14- and/or 28-day RDLMN assays. As a result, 14 out of the 16 hepatocarcinogens were positive, including 9 genotoxic hepatocarcinogens, which were reported negative in the bone marrow/peripheral blood micronucleus (MN) assay by a single treatment. These outcomes show the high sensitivity of the RDLMN assay to hepatocarcinogens. Regarding the specificity, 4 out of the 6 non-liver targeted genotoxic carcinogens gave negative responses. This shows the high organ specificity of the RDLMN assay. In addition to the RDLMN assay, we simultaneously conducted gastrointestinal tract MN assays using 6 of the above carcinogens as an optional trial of the collaborative study. The MN assay using the glandular stomach, which is the first contact site of the test chemical when administered by oral gavage, was able to detect chromosomal aberrations with 3 test chemicals including a stomach-targeted carcinogen. The treatment regime was the 14- and/or 28-day repeated-dose, and the regime is sufficiently promising to incorporate these methods into repeated-dose toxicological studies. The outcomes of our collaborative study indicated that the new techniques to detect chromosomal aberrations in vivo in several tissues worked successfully. PMID:25892619

  17. Japanese carbon storage in materials.

    PubMed

    Gielen, Dolf; Yagita, Hiroshi

    2002-02-01

    The NEAT model (Nonenergy-use Emission Accounting Tables) has been developed in order to estimate CO2 emissions caused by so-called nonenergy use of fossil fuels. The model is based on material flow accounting. The model has been applied to a number of countries in order to validate and improve its use. This paper discusses the case study for Japan. The NEAT analysis suggests that emissions in 1996 were 23 Mt higher than previously estimated based on the guidelines of the Intergovernmental Panel on Climate Change (IPCC). This quantity equals 1.9% of the total Japanese greenhouse gas emission. It is recommended to adjust the Japanese emission accounting practice and to apply more detailed emission estimation methods in future years. Given similar results for other countries it is also recommended to improve the IPCC guidelines. PMID:11928351

  18. The medaka mutation tintachina sheds light on the evolution of V-ATPase B subunits in vertebrates

    NASA Astrophysics Data System (ADS)

    Müller, Claudia; Maeso, Ignacio; Wittbrodt, Joachim; Martínez-Morales, Juan R.

    2013-11-01

    Vacuolar-type H+ ATPases (V-ATPases) are multimeric protein complexes that play a universal role in the acidification of intracellular compartments in eukaryotic cells. We have isolated the recessive medaka mutation tintachina (tch), which carries an inactivating modification of the conserved glycine residue (G75R) of the proton pump subunit atp6v1Ba/vatB1. Mutant embryos show penetrant pigmentation defects, massive brain apoptosis and lethality before hatching. Strikingly, an equivalent mutation in atp6v1B1 (G78R) has been reported in a family of patients suffering from distal renal tubular acidosis (dRTA), a hereditary disease that causes metabolic acidosis due to impaired kidney function. This poses the question as to how molecularly identical mutations result in markedly different phenotypes in two vertebrate species. Our work offers an explanation for this phenomenon. We propose that, after successive rounds of whole-genome duplication, the emergence of paralogous copies allowed the divergence of the atp6v1B cis-regulatory control in different vertebrate groups.

  19. 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.

  20. The potential immune modulatory effect of chronic bisphenol A exposure on gene regulation in male medaka (Oryzias latipes) liver.

    PubMed

    Qiu, Wenhui; Shen, Yang; Pan, Chenyuan; Liu, Shuai; Wu, Minghong; Yang, Ming; Wang, Ke-Jian

    2016-08-01

    Bisphenol A (BPA) is a well-known estrogenic endocrine disrupting chemical (EDC) ubiquitously present in various environmental media. The present study aims to identify the responsive genes in male fish chronically exposed to low concentrations of BPA at the transcription level. We screened genes from a suppression subtractive hybridization library constructed from male medaka (Oryzias latipes) livers after 60-d exposure to 10μg/L BPA under the condition at which changes of hepatic antioxidant parameters have been previously reported. The identified genes were predicted to be involved in multiple biological processes including antioxidant physiology, endocrine system, detoxification, notably associated with the immune response processes. With real time PCR analysis, the immune-associated genes including hepcidin-like precursor, complement component and factors, MHC class I, alpha-2-macroglobulin and novel immune-type receptor 6 isoform were significantly up-regulated in a nonmonotonic dose response pattern in livers upon exposure to different concentrations of BPA (0.1, 1, 10, 100, 1000μg/L). Our results demonstrated a negative impact on gene regulation in fish chronically exposed to relatively low and environmentally relevant concentrations of BPA, and suggested the potential immune modulatory effect of chronic EDC exposure on fish. The immunotoxicity of BPA and other EDCs should be much concerned for the health of human beings and other vertebrates exposed to it. PMID:27104808

  1. Effects of Space Flight-Associated Stimuli on Development of Murine and Medaka Sensory-Motor Systems

    NASA Technical Reports Server (NTRS)

    Wolgemuth, Debra J.

    1999-01-01

    The major goal of these studies was to continue investigations into the influence of altered gravitational fields on the development and function of the vertebrate brain and nervous system. Of major focus during the 18-month finding period of this award was the maintenance of the animals used in the experimental mouse and medaka model paradigms. The experiments focused on characterization of stress-sensitive periods in neural development and immediate or delayed effects on gene expression, physiology and behavior. The hypothesis under investigation was that the environment of space will have biologically significant effects on the development and function of the vertebrate nervous system. We have postulated that these effects will be more significant on certain neural compartments, such as the vestibular-motor system, and that these effects will have greater impact at particular stages of embryonic and post-natal development of the animal. Development of the central nervous system is well known for its vulnerability and sensitivity to environmental stimuli, although the effects of gravitational influences are poorly understood. The long-term goals of this research effort, initiated previously and continued in limited capacity during this interim period, were to provide important new information on the effects of altered environments during these critical periods.

  2. 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

  3. 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. PMID:26919805

  4. Development and swimming behavior of Medaka fry in a spaceflight aboard the Space Shuttle Columbia (STS-107).

    PubMed

    Niihori, Maki; Mogami, Yoshihiro; Naruse, Kiyoshi; Baba, Shoji A

    2004-09-01

    A space experiment aimed at closely observing the development and swimming activity of medaka fry under microgravity was carried out as a part of the S*T*A*R*S Program, a space shuttle mission, in STS-107 in January 2003. Four eggs laid on earth in an artificially controlled environment were put in a container with a functionally closed ecological system and launched on the Space Shuttle Columbia. Each egg was held in place by a strip of Velcro in the container to be individually monitored by close-up CCD cameras. In the control experiment, four eggs prepared using the same experimental set-up remained on the ground. There was no appreciable difference in the time course of development between space- and ground-based embryos. In the ground experiment, embryos were observed to rotate in place enclosed with the egg membrane, whereas those in the flight unit did not rotate. One of the four eggs hatched on the 8th day after being launched into space. All four eggs hatched in the ground unit. The fry hatched in space was mostly motionless, but with occasional control of its posture with respect to references in the experimental chamber. The fry hatched on ground were observed to move actively, controlling their posture with respect to the gravity vector. These findings suggest that the absence of gravity affects the initiation process of motility of embryos and hatched fry. PMID:15459450

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

    PubMed

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

    2016-01-01

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

  6. Prevalence of metabolic syndrome compared between native Japanese and Japanese-Americans.

    PubMed

    Yoneda, Masayasu; Yamane, Kiminori; Jitsuiki, Kuniaki; Nakanishi, Shuhei; Kamei, Nozomu; Watanabe, Hiroshi; Kohno, Nobuoki

    2008-03-01

    Metabolic syndrome is a condition characterized by the accumulation of multiple risk factors for atherosclerosis. Japanese-Americans in the U.S. have a more rapid and intense progression of atherosclerosis than native Japanese in Japan due to a westernization of their lifestyle. We investigated the prevalence of metabolic syndrome between 416 native Japanese (194 men and 222 women) in Hiroshima and 574 Japanese-Americans (217 men and 357 women) in Los Angeles, aged 30-89 years. According to the criteria proposed by the Japanese Society of Internal Medicine, the prevalence was 13.9 and 2.7% for native Japanese men and women, and 32.7 and 3.4% for Japanese-American men and women, respectively. According to the IDF or AHA/NHLBI criteria, the prevalence was 20.1 and 6.3%, and 38.7 and 4.5%, or 13.4 and 14.4%, and 30.9 and 27.7%, respectively. Thus, the prevalence of metabolic syndrome in men was significantly higher in Japanese-American than in native Japanese by all the three criteria. However, the prevalence in women was similar between native Japanese and Japanese-American by the Japanese and IDF criteria, whereas it was significantly higher in Japanese-American than in native Japanese by the AHA/NHLBI criteria. This report demonstrates that a westernization of lifestyle can increase the prevalence of metabolic syndrome among Japanese-Americans as compared to native Japanese. PMID:18006105

  7. Geochemical aspects of some Japanese lavas.

    NASA Technical Reports Server (NTRS)

    Philpotts, J. A.; Martin, W.; Schnetzler, C. C.

    1971-01-01

    K, Rb, Sr, Ba and rare-earth concentrations in some Japanese lavas have been determined by mass-spectrometric stable-isotope dilution. The samples fall into three rare-earth groups corresponding to tholeiitic, high alumina and alkali basalts. Japanese tholeiites have trace element characteristics similar to those of oceanic ridge tholeiites except for distinctly higher relative concentrations of Ba. Japanese lavas may result from various degrees of partial fusion of amphibole eclogite.

  8. Americans and Japanese Nonverbal Communication. Linguistic Communications 15 (Papers in Japanese Linguistics 3).

    ERIC Educational Resources Information Center

    Taylor, Harvey M.

    Each culture has its own nonverbal as well as its verbal language. Movements, gestures and sounds have distinct and often conflicting interpretations in different countries. For Americans communicating with Japanese, misunderstandings are of two types: Japanese behavior which is completely new to the American, and Japanese behavior which is…

  9. An experience in Japanese academic medicine.

    PubMed Central

    Tierney, L M

    1994-01-01

    The Japanese health care system has been highly praised for its universal access, freedom of patient choice, maintenance of a private system, and creative funding. Japanese citizens enjoy general good health, low infant mortality, and long life expectancy. Nevertheless, aspects of Japanese medical education, both graduate and undergraduate, and the structure of academic departments differ from those seen in the United States. A sabbatical spent teaching general internal medicine in Japan provided the experience for this review of the Japanese system. I describe the structure and function of departments of medicine and observations made at daily clinical teaching exercises in hospitals throughout the country. PMID:8160464

  10. In-vivo imaging of the fracture healing in medaka revealed two types of osteoclasts before and after the callus formation by osteoblasts.

    PubMed

    Takeyama, Kazuhiro; Chatani, Masahiro; Takano, Yoshiro; Kudo, Akira

    2014-10-15

    The fracture healing research, which has been performed in mammalian models not only for clinical application but also for bone metabolism, revealed that generally osteoblasts are induced to enter the fracture site before the induction of osteoclasts for bone remodeling. However, it remains unknown how and where osteoclasts and osteoblasts are induced, because it is difficult to observe osteoclasts and osteoblasts in a living animal. To answer these questions, we developed a new fracture healing model by using medaka. We fractured one side of lepidotrichia in a caudal fin ray without injuring the other soft tissues including blood vessels. Using the transgenic medaka in which osteoclasts and osteoblasts were visualized by GFP and DsRed, respectively, we found that two different types of functional osteoclasts were induced before and after osteoblast callus formation. The early-induced osteoclasts resorbed the bone fragments and the late-induced osteoclasts remodeled the callus. Both types of osteoclasts were induced near the surface on the blood vessels, while osteoblasts migrated from adjacent fin ray. Transmission electron microscopy revealed that no significant ruffled border and clear zone were observed in early-induced osteoclasts, whereas the late-induced osteoclasts had clear zones but did not have the typical ruffled border. In the remodeling of the callus, the expression of cox2 mRNA was up-regulated at the fracture site around vessels, and the inhibition of Cox2 impaired the induction of the late-induced osteoclasts, resulting in abnormal fracture healing. Finally, our developed medaka fracture healing model brings a new insight into the molecular mechanism for controlling cellular behaviors during the fracture healing. PMID:25131195

  11. The acute and regulatory phases of time-course changes in gill mitochondrion-rich cells of seawater-acclimated medaka (Oryzias dancena) when exposed to hypoosmotic environments.

    PubMed

    Kang, Chao-Kai; Yang, Wen-Kai; Lin, Shang-Tao; Liu, Chin-Cheng; Lin, Huei-Ming; Chen, Hong-Huan; Cheng, Chien-Wen; Lee, Tsung-Han; Hwang, Pung-Pung

    2013-01-01

    The recent model showed that seawater (SW) mitochondrion-rich (MR) cells with hole-type apical openings secrete Cl(-) through the transporters including the Na(+), K(+)-ATPase (NKA), Na(+), K(+), 2Cl(-) cotransporter (NKCC), and cystic fibrosis transmembrane conductance regulator (CFTR). The present study focused on the dynamic elimination of the Cl(-) secretory capacity and illustrated different phases (i.e., acute and regulatory phases) of branchial MR cells in response to hypoosmotic challenge. Time-course remodeling of the cell surfaces and the altered expressions of typical ion transporters were observed in the branchial MR cells of SW-acclimated brackish medaka (Oryzias dancena) when exposed to fresh water (FW). On the 1st day post-transfer, rapid changes were shown in the acute phase: the flat-type MR cells with large apical surfaces replaced the hole-type cells, the gene expression of both Odnkcc1a and Odcftr decreased, and the apical immunostaining signals of CFTR protein disappeared. The basolateral immunostaining signals of NKCC1a protein decreased throughout the regulatory phase (>1day post-transfer). During this period, the size and number of NKA-immunoreactive MR cells were significantly reduced and elevated, respectively. Branchial NKA expression and activity were maintained at constant levels in both phases. The results revealed that when SW-acclimated brackish medaka were transferred to hypoosmotic FW for 24h, the Cl(-) secretory capacity of MR cells was eliminated, whereas NKCC1a protein was retained to maintain the hypoosmoregulatory endurance of the gills. The time-course acute and regulatory phases of gill MR cells showed different strategies of the euryhaline medaka when subjected to hypoosmotic environments. PMID:22960413

  12. Embryonic Medaka Model of Microglia in the Developing CNS Allowing In Vivo Analysis of Their Spatiotemporal Recruitment in Response to Irradiation

    PubMed Central

    Yasuda, Takako; Oda, Shoji; Hibi, Yusuke; Satoh, Satomi; Nagata, Kento; Hirakawa, Kei; Kutsuna, Natsumaro; Sagara, Hiroshi; Mitani, Hiroshi

    2015-01-01

    Radiation therapy (RT) is pivotal in the treatment of many central nervous system (CNS) pathologies; however, exposure to RT in children is associated with a higher risk of secondary CNS tumors. Although recent research interest has focused on the reparative and therapeutic role of microglia, their recruitment following RT has not been elucidated, especially in the developing CNS. Here, we investigated the spatiotemporal dynamics of microglia during tissue repair in the irradiated embryonic medaka brain by whole-mount in situ hybridization using a probe for Apolipoprotein E (ApoE), a marker for activated microglia in teleosts. Three-dimensional imaging of the distribution of ApoE-expressing microglia in the irradiated embryonic brain clearly showed that ApoE-expressing microglia were abundant only in the late phase of phagocytosis during tissue repair induced by irradiation, while few microglia expressed ApoE in the initial phase of phagocytosis. This strongly suggests that ApoE has a significant function in the late phase of phagocytosis by microglia in the medaka brain. In addition, the distribution of microglia in p53-deficient embryos at the late phase of phagocytosis was almost the same as in wild-type embryos, despite the low numbers of irradiation-induced apoptotic neurons, suggesting that constant numbers of activated microglia were recruited at the late phase of phagocytosis irrespective of the extent of neuronal injury. This medaka model of microglia demonstrated specific recruitment after irradiation in the developing CNS and could provide a useful potential therapeutic strategy to counteract the detrimental effects of RT. PMID:26061282

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

    PubMed

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

    2015-09-01

    Although several previous studies have demonstrated the presence of equine estrogens in the aquatic environment, limited data are currently available on the endocrine-disrupting potentials in fish and the risks they pose to aquatic organisms. To investigate the interactions of major equine estrogens equilin (Eq) and equilenin (Eqn), as well as their metabolites 17α-dihydroequilin, 17β-dihydroequilin, 17α-dihydroequilenin and 17β-dihydroequilenin, with the estrogen receptor α (ERα) of medaka (Oryzias latipes), a three-dimensional model of the ligand-binding domain (LBD) of ERα was built in silico, and docking simulations were performed. The docking simulation analysis indicated that the interaction of 17β-dihydroequilenin with the ERα LBD is the most potent, followed by those of 17α-dihydroequilin and 17β-dihydroequilin, whereas those of Eq and Eqn were least potent. We further analyzed gene expression profiles in the livers of male medaka exposed to Eq and Eqn. A DNA microarray representing 6000 genes revealed that 24-h exposure to Eq and Eqn (100 ng/L) upregulated the expression of 6 and 34 genes in the livers of males, respectively. Genes upregulated by Eq included the estrogenic biomarker genes vitellogenins and choriogenins, suggesting the estrogenic potential of Eq. In contrast, Eqn exposure upregulated several cancer-related genes, such as mediator complex subunit 16 and RAS oncogene family members, suggesting a carcinogenic potential for Eqn. These results suggest that equine estrogens may have not only endocrine-disrupting potentials via the ERα signaling pathway but also carcinogenic potency in male medaka. PMID:25611945

  14. Polycystic kidney disease in the medaka (Oryzias latipes) pc mutant caused by a mutation in the Gli-Similar3 (glis3) gene.

    PubMed

    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

  15. A Confirmatory Model for Substance Use Among Japanese American and Part-Japanese American Adolescents

    PubMed Central

    Williams, John Kino Yamaguchi; Else, 'Iwalani R. N.; Goebert, Deborah A.; Nishimura, Stephanie T.; Hishinuma, Earl S.; Andrade, Naleen N.

    2013-01-01

    Few studies have examined the effect of ethnicity and cultural identity on substance use among Asian and Pacific Islander adolescents. A cross-sequential study conducted in Hawai'i with 144 Japanese American and part-Japanese American adolescents assessed a model integrating Japanese ethnicity, cultural identity, substance use, major life events, and social support. Japanese American adolescents scored higher on the Japanese Culture Scale and on the Peers’ Social Support than the part-Japanese American adolescents. Significant associations for substance use and impairment included culturally intensified events and Japanese cultural identity- behavior subset. Models had good overall fits and suggested that conflict surrounding cultural identity may contribute to substance use. PMID:23480213

  16. A confirmatory model for depression among Japanese American and part-Japanese American adolescents.

    PubMed

    Williams, John Kino Yamaguchi; Else, 'Iwalani R N; Hishinuma, Earl S; Goebert, Deborah A; Chang, Janice Y; Andrade, Naleen N; Nishimura, Stephanie T

    2005-02-01

    A confirmatory model integrating Japanese ethnicity, cultural identity, and depression was developed (N = 140). The model incorporated the Center for Epidemiologic Studies-Depression Scale (CES-D), Major Life Events Scale, and Japanese Cultural Scale. Japanese American adolescents scored higher on the Japanese Cultural Scale and reported fewer depressive symptoms on the CES-D total and on 2 of the 3 CES-D factors than part-Japanese American adolescents. Predictors for depression were being Japanese American vs. part-Japanese American, female gender, and culturally intensified events. A significant interaction of behavior by self-identification was noted. The model had good overall fit and suggested that the formation of cultural identity may contribute to depressive symptoms experienced by adolescents, particularly adolescents of mixed heritage. PMID:15727494

  17. C3 variants in Japanese.

    PubMed

    Nishimukai, H; Kitamura, H; Sano, Y; Tamaki, Y

    1985-01-01

    By high-voltage agarose gel electrophoresis, seven phenotypes of C3 were found in Japanese. The allele frequencies for C3*S, C3*S025, C3*S02, C3*F, C3*F06, C3*F065, and C3*F08 were 0.9943, 0.0003, 0.0003, 0.0006, 0.0003, 0.0021, and 0.0021, respectively. CH50, C3/C3c protein concentrations, and C3 hemolytic activities in fresh sera with variant C3 phenotypes were within the normal ranges. PMID:3988301

  18. The Teaching of Japanese in Australia.

    ERIC Educational Resources Information Center

    Marriott, Helen E.

    1992-01-01

    The article surveys the development of Japanese language courses in Australia, noting a variety of factors contribute to the growth and recent intensification of interest in the subject. It examines problems within Japanese language teaching and discusses further innovative course development, differentiation of needs, employer perceptions, and…

  19. Classroom Silence: Voices from Japanese EFL Learners

    ERIC Educational Resources Information Center

    Harumi, Seiko

    2011-01-01

    This article explores Japanese EFL learners' classroom silence in a Japanese EFL context. The existence of silence in second language learning contexts can be a source of conflict between students and teachers and even among students themselves. It can also be an obstacle to acquiring the target language. In order to tackle this problem and to…

  20. Interpersonal Mistrust and Unhappiness among Japanese People

    ERIC Educational Resources Information Center

    Tokuda, Yasuharu; Inoguchi, Takashi

    2008-01-01

    Our main objective in this paper is to evaluate the possible association between interpersonal mistrust and unhappiness among Japanese people. Based on cross-sectional data for the Japanese general population from the Asia Barometer Survey (2003-2006), we analyzed the relationship between interpersonal mistrust and unhappiness using a logistic…