DMRT1 in Mammalian Sexual Development

描述（由申请人提供）：我们鉴定了第一类广泛保守的性调节基因，即与果蝇doubletex基因相关的转录因子。它们共享一个独特的锌指DNA结合结构域，我们将其命名为DM结构域。在当前的资金周期中，我们研究了Dmrt 1的功能，Dmrt 1是该基因家族的哺乳动物成员。人DMRT 1定位于染色体9p上的一个短片段，该片段在睾丸发育不全中缺失。我们发现，小鼠Dmrt 1的无效突变导致睾丸分化严重缺陷，并导致至少一种菌株背景下的性逆转。我们在其他物种中的表达研究表明，Dmrt1可能是所有脊椎动物睾丸发育所必需的，包括那些具有高度分化的性别决定机制的动物。 我们提出的工作的目的是阐明Dmrt 1和两个相关基因控制哺乳动物性腺发育的机制，在遗传和分子水平。 我们有四个目标。在目的1中，我们调查已知的性调节基因Dmrt 1控制在胚胎性腺。我们还将测试相关基因Dmrt3的功能。Dmrt3在胚胎睾丸中表达，其人类同源物，如DMRT1，受到性别逆转人类9p缺失的影响。在目标2中，我们寻找睾丸中Dmrt 1调控的其他靶点，并测试哪些是直接调控的。在目标3中，我们研究了Dmrt 1蛋白如何控制转录，测试了与Dmrt 1特异性相互作用的候选转录辅助调节因子的功能重要性。在目的4中，我们研究了卵巢特异性基因Dmrt 5在性腺发育中的作用，该基因与Dmrt 1相关，测试它是否在雌性中起类似于Dmrt 1在雄性中的作用。我们的工作将有助于揭示哺乳动物性分化的分子基础和建立调控基因通路。这也将推进我们对人类先天性缺陷的病因学在这一关键过程中的理解。

DESCRIPTION (provided by applicant): We identified the first widely conserved class of sexual regulatory genes, transcription factors related to the Drosophila doublesex gene. These share a unique zinc finger DNA binding domain we named the DM domain. In the current funding cycle we have investigated the function of Dmrt1, a mammalian member of this gene family. Human DMRT1 maps to a short segment on chromosome 9p that is deleted in testis dysgenesis. We showed that a null mutation in murine Dmrt1 causes severe defects in testis differentiation and causes sex reversal on at least one strain background. Our expression studies in other species showed that Dmrt1 is probably required for testis development in all vertebrates, including those with highly diverged sex determination mechanisms. The objective of the work we propose is to elucidate the mechanisms by which Dmrt1 and two related genes control mammalian gonad development, at both the genetic and molecular levels. We have four aims. In Aim 1, we investigate which of the known sexual regulatory genes Dmrt1 controls in the embryonic gonad. We also will test the function of a related gene, Dmrt3. Dmrt3 is expressed in the embryonic testis and its human homologue, like DMRT1, is affected by sex reversing human 9p deletions. In Aim 2 we search for additional targets of Dmrt1 regulation in the testis, and test which are regulated directly. In Aim 3 we investigate how the Dmrt1 protein controls transcription, testing the functional importance of candidate transcriptional coregulators that specifically interact with Dmrt1. In Aim 4, we investigate the role in gonad development of Dmrt5, an ovary-specific gene related to Dmrt1, testing whether it plays a role in females analogous to that of Dmrt1 in males. Our work will help to reveal the molecular basis of mammalian sexual differentiation and to establish a pathway of regulatory genes. This will also advance our understanding of the etiology of human congenital defects in this critical process.