Analysis of Sexual Plasticity in Gonads by AMH System

在这一预算的支持下，我们首次阐明了性腺性可塑性的分子和细胞机制，AMH系统参与了这一机制。我们发现这个系统在卵巢中我们称之为“生发摇篮”的地方起作用，那里存在生殖系干细胞。这是脊椎动物卵巢中干细胞和生态位结构的首次成功展示。AMH系统在生发摇篮中以滤泡间方式起作用，并间接调节干细胞亚群的增殖。性的可塑性也是通过生殖细胞的调节来控制的。这说明生发摇篮不仅具有调节卵数的作用，而且具有性可塑性。动物和哺乳动物AMH系统的功能不同。我们还发现，哺乳动物睾丸形成的另一个重要基因sox9在medaka性腺的雄性化中不起作用。结合功能分析，我们的研究共同表明，脊椎动物的不同物种发展了自己的性别决定系统。

With support of this budget, we firstly clarified the molecular and cellular mechanism of sexual plasticity in the gonads and AMH system is involved in this mechanism. We discovered that this system functions in what we named 'Germinal Cradle' in the ovary, in which germline stem cells are present. This was the first successful demonstration of stem cells and niche structure in vertebrate ovary. The AMH system functions in interfollicular manner in the Germinal Cradles and indirectly regulates proliferation of subpopulation of stem cells. The sexual plasticity is also controlled through the regulation of germ cells. This indicates that Germinal Cradles is not only for regulation of the egg number but also for sexual plasticity.The function of AMH system differs in medaka and mammals. We also revealed that sox9, another important gene for testis formation in mammals, does not functions in masculinization of medaka gonads. Together with functional analysis, our studies collectively indicate that different species in vertebrates develop their own system of sex determination.