2017 Fiscal Year Final Research Report
The mechanism for sex reversal in ovarian aromatase loss-of-function mutant medaka
| 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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| Keywords | 性分化 / 性転換 / 性的可塑性 / メダカ / エストロゲン |
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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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| Free Research Field |
生殖内分泌学
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