Gonadal plasticity of DMRT1 mutants in the medaka

Dmrt1存在于许多脊椎动物中，在性别分化时期表现出睾丸特异性表达，表明Dmrt1在脊椎动物性腺睾丸发育中具有保守功能。然而，功能性分析只在哺乳动物中有报道。目前的研究重点是Dmrt1在具有XX-XY性别决定系统的硬骨鱼（Oryzias latipes）中的功能。尽管medaka的性别是由Y染色体特异性基因Dmy的存在与否决定的，但我们证明，在筛选基因驱动突变文库发现的一个Dmrt1突变系中，XY突变体发育成正常雌性并产卵。这些结果表明，Dmrt1在dmy触发的雄性分化途径后维持睾丸分化至关重要。

Dmrt1, which is found in many verte brates, exhibits testis-specific expression during the sexual differentiation period, suggesting a conserved function of Dmrt1 in the testicular development of vertebrate gonads. However, functional analyses have been reported only in mammals. The current study focused on the Dmrt1 function in the teleost medaka, Oryzias latipes, which has an XX-XY sex determina tion system. Although medaka sex is determined by the presence or absence of the Y chromosome-specific gene Dmy, we demonstrated that in one Dmrt1 mutant line, which was found by screening a gene-driven mutagenesis library, XY mutants developed into nor mal females and laid eggs. These results show that Dmrt1 is essential to maintain testis differentiation after Dmy-triggered male differentiation pathway.