DMRT1 in mammalian sexual development

描述（由申请人提供）：拟议工作的总体目标是了解Dmrt 1基因如何控制睾丸的发育和功能。睾丸有两个基本功能：产生精子，作为男性生殖系DNA永生的载体的细胞;以及产生激素，指导身体的其他部分以男性特有的方式发育。dmrt 1是一个保守的转录调控因子家族，在哺乳动物睾丸中控制着多个关键过程。这项工作与人类健康直接相关：人类DMRT 1的丢失与男性到女性的性别逆转，性分化障碍（DSD），不育和睾丸生殖细胞肿瘤（TGCT）有关。在小鼠中，Dmrt 1控制胚胎性腺中的生殖细胞多能性，并控制成年人的有丝分裂/减数分裂决定。一个新的发现是，睾丸决定必须积极维护出生后的Dmrt 1和Dmrt 1突变的睾丸经历大规模的出生后重编程成为卵巢样器官。该提案有三个目标，重点是加深我们对DMRT 1如何控制睾丸中关键过程的理解。目的1探讨DMRT 1如何阻止出生后睾丸的转分化。这是一个新发现的、未经研究的生物学过程。拟议的实验使用条件基因靶向方法来询问DMRT 1是否会阻止出生后胎儿性别决定网络的重新激活，确定出生后性别维持的新调节因子，并使用ChIP-seq来确定小鼠和人类睾丸中与DMRT 1结合的基因。目的2采用精确控制的功能丧失和获得方法，验证DMRT 1在精原干细胞向定向祖细胞转化中的关键作用。目的3将确定DMRT 1是如何失活的精原细胞从有丝分裂到减数分裂的过渡，并将测试当这未能发生的后果。这项研究的结果应该有助于治疗性腺癌和不育症，并将为细胞命运重编程和新型男性避孕药设计的研究提供信息。

DESCRIPTION (provided by applicant): The overall objective of the proposed work is to understand how the Dmrt1 gene controls development and function of the testis. The testis has two essential functions: production of sperm, the cells that serve as vehicles for the immortality of male germ line DNA; and production of hormones that direct other parts of the body to develop in a male-specific manner. Dmrt1 belongs to family of conserved transcriptional regulators and controls multiple critical processes in the mammalian testis. This work has direct human health relevance: loss of DMRT1 in humans is associated with male-to-female sex reversal, disorders of sexual differentiation (DSD), infertility, and testicular germ cell tumors (TGCTs). In mice Dmrt1 controls germ cell pluripotency in the fetal gonad and controls the mitosis/meiosis decision in adults. A new discovery is that testis determination must be actively maintained postnatally by Dmrt1 and that Dmrt1 mutant testes undergo massive postnatal reprogramming to become ovary-like organs. This proposal has three aims focused on deepening our understanding of how DMRT1 controls key processes in the testis. Aim 1 asks how DMRT1 prevents transdifferentiation in the postnatal testis. This is a newly discovered and unstudied biological process. The proposed experiments use conditional gene targeting approaches to ask whether DMRT1 prevents reactivation of the fetal sex determination network postnatally, identify new regulators of postnatal sex maintenance, and use ChIP-seq to identify genes that are bound by DMRT1 in the mouse and human testis. Aim 2 tests the hypothesis that DMRT1 is critical for the transition from spermatogonia stem cell to committed progenitor cell, using precisely controlled loss- and gain-of-function approaches. Aim 3 will determine how DMRT1 is inactivated as spermatogonia transition from mitosis to meiosis and will test the consequences when this fails to occur. The results of this study should aid in treatment of gonadal cancer and infertility, and will inform studies of cell fate reprogramming and design of novel male contraceptives.