| Project/Area Number |
26840107
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Morphology/Structure
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| Research Institution | Tokyo University of Marine Science and Technology |
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Principal Investigator |
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| Research Collaborator |
NAGAHAMA Yoshitaka 愛媛大学, 社会連携機構, 教授
Young Graham University of Washington, School of Aquatic and Fishery Sciences, 教授
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| Project Period (FY) |
2014-04-01 – 2018-03-31
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| Project Status |
Completed (Fiscal Year 2017)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 性分化 / 性転換 / 性的可塑性 / メダカ / エストロゲン / 卵巣分化 / 卵巣形成 / 硬骨魚類 / 魚類 / 内分泌学 / 分子生物学 |
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| Outline of Final Research Achievements |
Although estrogens have been generally considered to play a critical role in ovarian differentiation in non-mammalian vertebrates, the specific functions of estrogens during ovarian differentiation remain unclear. We isolated two mutants with premature stops in the ovarian aromatase (cyp19a1) gene from a mutagenesis library of the medaka, Oryzias latipes. In XX mutants, gonads first differentiated into normal ovaries containing many ovarian follicles that failed to accumulate yolk. Subsequently, ovarian tissues underwent extensive degeneration, followed by the appearance of testicular tissues. During the initial phase of degeneration of ovarian tissues, the genes involved in synthesis of non-aromatizable androgens were up-regulated. Our results suggest that the imbalance of estrogens and androgens, especially the potential for an increase in androgens could be part of the mechanism that induced degeneration of ovarian follicles in ovaries and sex reversal of cyp19a1 mutants.
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