Global Genome Analysis of the Downstream Binding Targets of Testis Determining Factor SRY and SOX9 [SOX9 ChIP]

A major event in mammalian male sex determination is the induction of the testis determining factor Sry and its downstream gene Sox9. The current study provides one of the first genome wide analyses of the downstream gene binding targets for SRY and SOX9 to help elucidate the molecular control of Sertoli cell differentiation and testis development. A modified ChIP-Chip analysis using a comparative hybridization was used to identify 71 direct downstream binding targets for SRY and 109 binding targets for SOX9. Interestingly, only 5 gene targets overlapped between SRY and SOX9. In addition to the direct response element binding gene targets, a large number of atypical binding gene targets were identified for both SRY and SOX9. Bioinformatic analysis of the downstream binding targets identified gene networks and cellular pathways potentially involved in the induction of Sertoli cell differentiation and testis development. The specific DNA sequence binding site motifs for both SRY and SOX9 were identified. Observations provide insights into the molecular control of male gonadal sex determination.哺乳动物雄性性别决定过程中的核心事件，为睾丸决定因子Sry（Sex-determining Region Y）及其下游靶基因Sox9（SRY-box 9）的诱导表达。本研究开展了首批全基因组范围内SRY与SOX9下游结合靶基因的分析，旨在阐明支持细胞（Sertoli cell）分化与睾丸发育的分子调控机制。研究采用改良的比较杂交染色质免疫沉淀芯片（Chromatin Immunoprecipitation-chip, ChIP-Chip）技术，分别鉴定得到71个SRY直接下游结合靶基因以及109个SOX9结合靶基因。值得注意的是，SRY与SOX9的共有结合靶基因仅为5个。除直接响应元件结合靶基因外，研究还为二者分别鉴定出大量非典型结合靶基因。对下游结合靶基因的生物信息学分析，揭示了可能参与支持细胞分化与睾丸发育调控的基因调控网络与细胞通路。本研究同时鉴定得到SRY与SOX9的特异性DNA序列结合基序。本研究结果为雄性性腺性别决定的分子调控机制提供了新的见解。