Dmrt1 in mammalian sexual development

描述（由申请人提供）：拟议工作的目的是了解Dmrt1基因如何控制睾丸的发育和功能。睾丸有两个基本功能：制造精子，精子是男性生殖系DNA不朽的载体；并产生激素，指导身体其他部位以男性特有的方式发育。我们发现了Dmrt家族的保守转录调控因子，并表明一些Dmrt蛋白对脊椎动物的性腺发育很重要。DMRT1缺失会导致睾丸发育的严重缺陷，并且在人类中，与男性向女性的性别逆转有关。最近，我们发现129/Sv小鼠品系需要Dmrt1来控制生殖细胞的多能性，阻止这些细胞形成身体的其他细胞类型而不是精子。该提议的主要假设是Dmrt1在控制生殖系干细胞中起着核心作用，在干细胞本身和周围的支持细胞（称为Sertoli细胞）的不同阶段都起作用。我们有四个目标。Aim 1询问DMRT1如何控制胚胎中的生殖细胞多能性。我们将确定Dmrt1突变的胚胎生殖细胞在失去其正常命运承诺时的变化，确定Dmrt1是否控制生殖细胞或支持细胞的这一过程，并确定生殖细胞多能性的候选调节因子。目的2测试DMRT1在成体精子发生中的功能，重点是成体生殖系干细胞。我们将使用一种创新的遗传策略来确定Dmrt1在成体生殖系干细胞中的作用。目的3旨在通过确定DMRT1在新生儿睾丸中直接调节的基因来阐明DMRT1的功能。目的4验证了Dmrt1与相邻的Dmrt3基因协同指导胚胎睾丸发育的假设，评估了Dmrt3和Dmrt1Dmrt3双突变体在致敏遗传背景下的表型。这将为去除这两个基因的人类性别逆转缺失提供一个小鼠模型。

DESCRIPTION (provided by applicant): The 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. We discovered the Dmrt family of conserved transcriptional regulators and have shown that several DMRT proteins are important for gonadal development in vertebrates. Loss of DMRT1 causes severe defects in testis development and, in humans, is associated with male-to- female sex reversal. Recently we found that Dmrt1 is required in the 129/Sv mouse strain to control germ cell pluripotency, preventing these cells from forming other cell types of the body rather than sperm. The main hypothesis of this proposal is that Dmrt1 plays a central role in controlling germ line stem cells, acting at different stages both in the stem cells themselves and in surrounding support cells called Sertoli cells. We have four aims. Aim 1 asks how DMRT1 controls germ cell pluripotency in the embryo. We will identify changes in Dmrt1 mutant embryonic germ cells as they lose their normal fate commitment, determine whether Dmrt1 controls this process in the germ cells or the Sertoli cells, and identify candidate regulators of germ cell pluripotency. Aim 2 tests the function of DMRT1 during adult spermatogenesis, focusing on adult germ line stem cells. We will use an innovative genetic strategy to determine the role of Dmrt1 in adult germ line stem cells. Aim 3 seeks to illuminate the function of DMRT1 by identifying the genes it directly regulates in the neonatal testis. Aim 4 tests the hypothesis that Dmrt1 acts with the adjacent Dmrt3 gene to coordinately direct embryonic testis development, assessing the phenotype of Dmrt3 and Dmrt1Dmrt3 double mutants on sensitized genetic backgrounds. This will provide a mouse model for human sex-reversing deletions that remove the two genes. The work we propose is highly relevant to human health. DMRT1 is implicated in human infertility, in testicular dysgenesis, and in testicular cancer. Our studies may permit better diagnosis and treatment of these conditions. Furthermore, because Dmrt1 plays a role in controlling germ line pluripotency, our work may aid in the use of germ line stem cells for therapeutic cloning and for restoration of fertility after chemotherapy.