Global Genome Analysis of the Downstream Binding Targets of Testis Determining Factor SRY and SOX9 [SRY 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中的核心事件，是睾丸决定因子Sry（Sex-determining Region Y）及其下游基因Sox9（SRY-box 9）的诱导表达。本研究针对SRY与SOX9的下游基因结合靶点开展全基因组分析，为阐明支持细胞分化与睾丸发育的分子调控机制提供了重要依据。本研究采用改良的比较杂交染色质免疫沉淀芯片（ChIP-Chip）分析方法，分别鉴定得到71个SRY直接下游结合靶点与109个SOX9结合靶点。值得注意的是，SRY与SOX9仅共享5个共同基因靶点。除直接响应元件结合基因靶点外，本研究还为SRY与SOX9分别鉴定出大量非典型结合基因靶点。对下游结合靶点的生物信息学分析，揭示了可能参与支持细胞分化与睾丸发育诱导的基因调控网络与细胞通路。此外，本研究还鉴定得到SRY与SOX9的特异性DNA序列结合基序。上述发现为雄性性腺性别决定的分子调控机制提供了新的见解。