Control by tra-1 of Sexual Differentiation in C. elegans

描述（由申请人提供）：该项目的长期目标是利用秀丽隐杆线虫了解性别二态性和性别特异性器官发生的分子基础。性别分化是正常发育的核心，但控制它的分子机制却知之甚少。本应用程序的重点是两性二态特征，男性感觉射线（V射线）和体细胞性腺，它们作为性别特异性神经系统发育和性别特异性器官发生的范例。核心假设是，特定的调节途径作用于主调节剂TRA-1的下游，以控制特定组织和器官的性别分化。该实验室此前发现了两个关键的下游因子：DM结构域蛋白MAB-3和叉头蛋白FKH-6。在强有力的初步数据的指导下，我们的具体目的是阐明性别特异性神经系统发育是如何通过TRA-1和MAB-3在雄性尾巴中调节的，以及性别特异性性腺激素是如何由TRA-1和FKH-6控制的。第一个目的是研究MAB-3抑制雄性抗神经bHLH基因ref-1的机制，评估候选MAB-3共抑制因子，发现激活ref-1的蛋白，并研究TRA-1的作用。第二个目的是确定FKH-6的调控靶点和FKH-6突变体的抑制因子，评估候选的FKH-6共调控因子，并研究TRA-1如何拮抗和增强FKH-6的功能。拟议的研究将利用创新的方法，包括基于信息学的靶基因鉴定、体内DNA结合测定、“表型”数据库的挖掘以及可诱导的组织特异性RNAi方法的开发，揭示一个关键但鲜为人知的发展方面的分子基础。这项工作与人类健康有明显的相关性：DM结构域蛋白和叉头蛋白控制哺乳动物的性别分化，我们最近发现DM结构域基因的突变会导致睾丸癌。性别分化失败导致性别逆转、性别模糊、泌尿生殖畸形、不孕症和性腺癌。该建议研究DM结构域蛋白与保守染色质调节因子的相互作用，可能为治疗剂的开发开辟道路。

DESCRIPTION (provided by applicant): The long-term goal of this project is to use C. elegans to understand the molecular basis of sexual dimorphism and sex-specific organogenesis. Sexual differentiation is central to normal development but the molecular mechanisms controlling it are poorly understood. The focus of this application is on two sexually dimorphic features, male sensory rays (V rays) and the somatic gonad, which serve as paradigms for sex-specific nervous system development and sex-specific organogenesis. The central hypothesis is that specific regulatory pathways act downstream of the master regulator TRA-1 to control sexual differentiation of specific tissues and organs. This laboratory previously discovered two key downstream factors: the DM domain protein MAB-3, and the forkhead protein FKH-6. Guided by strong preliminary data, our specific aims are to elucidate how sex-specific nervous system development is regulated in the male tail by TRA-1 and MAB-3, and how sex-specific gonadogenesis is controlled by TRA-1 and FKH-6. The first aim investigates the mechanism by which MAB-3 represses the antineural bHLH gene ref-1 in males, evaluates candidate MAB-3 corepressors, finds a protein that activates ref-1, and investigates the role of TRA-1. The second aim identifies targets of FKH-6 regulation and suppressors of fkh-6 mutants, evaluates candidate FKH-6 coregulators, and investigates how TRA-1 both antagonizes and potentiates FKH-6 functions. The proposed research will uncover the molecular basis of a critical but poorly understood aspect of development, using innovative approaches including informatics-based identification of target genes, in vivo DNA binding assays, mining of "phenome" databases, and development of inducible tissue- specific RNAi methods. This work has clear relevance to human health: DM domain proteins and forkhead proteins control sexual differentiation in mammals, and we recently discovered that mutations in a DM domain gene cause testicular cancer. Failure of sexual differentiation causes sex reversal, sexual ambiguity, urogenital malformation, infertility, and gonadal cancer. This proposal investigates DM domain protein interactions with conserved chromatin regulators, potentially opening the way to development of therapeutic agents.