性类固醇激素的反馈调节在哺乳动物生殖活动中的作用和机制已被阐明。但是，作为脊椎动物中种类最多的鱼类，其类固醇激素的反馈调节仍不清楚。最近基因敲除的证据揭示，促性腺激素在鱼类生殖活动中的地位突出，可能作为性类固醇激素反馈调节的一个突破口。目前性类固醇激素对促性腺激素的调节，仅集中在雌雄异体鱼类中的初步研究，而雌雄同体鱼类中的这方面研究还是空白。基于此，我们在在雌雄同体斜带石斑鱼中初步研究显示：雄激素对垂体中两种促性腺激素的调节作用不同。但具这种差异调节的分子机制尚需进一步研究。本项目拟以斜带石斑鱼为研究对象，采用双色原位杂交共定位、性腺切除与激素补偿、启动子点突变及CHIP方法，旨在解答性类固醇激素调控雌雄同体鱼类促性腺激素的作用及分子机制。本项目的研究将填补鱼类性类固醇激素反馈调节研究中的空白，也将加深我们对脊椎动物生殖调控的认识，同时也将为揭示雌雄同体鱼类性逆转的机制提供参考。

The feedback regulation mechanism of sex steroids in reproductive activities has been elucidated in mammalian. However, the feedback regulation of steroids in fish, as the most abundant species in vertebrates, remains unclear. Recent studies using gene knockout reveal that gonadotropins play a prominent role in fish reproductive activities and may serve as a breakthrough in the regulation of sex steroids feedback. The preliminary study of the sex steroid regulation on gonadotropins has only focused on hermaphroditic fishes, but the study on hermaphrodite fishes is still blank. Based on this, we have conducted preliminary studies in the hermaphrodite grouper. Our results showed that the androgen had different regulation on the two kinds of gonadotropins, but with the molecular mechanism of this difference needs further study. This project, using orange-spotted grouper as the experimental model, intends to investigate the molecular mechanisms effects of sex steroid on the regulation of gonadal hormones in hermaphrodite fish by using two-color in situ hybridization, gonadectomy and hormone replacement, promoter point mutation and CHIP method. The research of this project will fill in the blank of the research on the sex steroid feedback regulation and will also deepen our understanding of vertebrate reproductive regulation and provide a reference for revealing the mechanism of hermaphroditism.