Gonadal plasticity of DMRT1 mutants in the medaka

Dmrt 1在许多脊椎动物中发现，在性分化期间表现出睾丸特异性表达，表明Dmrt 1在脊椎动物性腺的睾丸发育中具有保守的功能。然而，功能分析仅在哺乳动物中报道。本研究主要探讨了Dmrt 1基因在具有XX-XY性别决定系统的青鳉中的功能。虽然青鳉性别是由Y染色体特异性基因Dmy的存在或不存在决定的，但我们证明了在一个Dmrt 1突变系中，通过筛选基因驱动的诱变文库发现，XY突变体发育成正常雌性并产卵。这些结果表明，Dmrt 1是必不可少的，以维持睾丸分化后，Dmy触发的雄性分化途径。

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.