dmrt1 4种选择性剪切本在黄鳝性别分化和转换中的功能及调控机制研究

黄鳝性反转机制是极富挑战的研究课题。因性反转特性导致的苗种匮乏是制约黄鳝养殖业的瓶颈。相比于性别决定因子，鱼类的性别分化信号通路和因子相对保守。dmrt1在后生动物性别分化中具有保守且重要的作用。已报道dmrt1在黄鳝等多个物种性别分化过程中发生选择性剪切，各剪切本表达趋势不同，但剪切本在性别分化中的功能尚未知。我们发现完全敲除dmrt1的黄鳝提前性反转为雄性，这一出乎意料的表型提示，dmrt1的选择性剪切本可能在黄鳝性别分化和转换过程中起到重要且独特的作用。本项目拟分析dmrt1各转录本在正常或异常性反转黄鳝的性腺表达特征；研制表达dmrt1单一转录本的黄鳝；发掘各转录本的靶基因；分析各转录本的顺式调控元件和反式作用因子。以期初步解析黄鳝dmrt1 4种主要转录本在性别分化和转换过程中的功能及调控机制，为探索黄鳝性腺分化和发育的规律、进而人为控制、以获得大体型雌亲鳝和早熟雄亲鳝提供指导。

The study of the mechanism underlying the sex reversal of the rice field eel is a challenging project in life science. The deficiency of the fries for aquaculture is like a bottleneck restricting the production yield increase of the rice field eel, due to the sex reversal traits. Compared with sex determinators, the sex differentiation signal pathways as well as factors involved are relatively conserved among fish. The dmrt1 gene plays an important and conserved role in sex differentiation of extensive metazoan species. Alternative splicing of dmrt1 gene is reported during sex differentiation in many animals including the rice field eel, producing various transcripts with different expression tendency, whose exact functions are still unkown at the present. We knocked out dmrt1 in the rice field eel and found the time for sex reversal of the mutant fish was shifted to an earlier date, which was unexpected and suggested us the alternative splicing transcripts of dmrt1 might have a vital and unique role in the sex differentiation and sex reversal in the rice field eel. In this project, the gonadal expression characteristics of dmrt1 transcripts will be identified in the rice field eel undergoing normal or abnormal sex reversal. The rice field eel with ectopic dmrt1 transcript expressing will be produced. The effecting targets of each dmrt1 transcript will be identified, as well as the cis-acting elements and trans-acting factors. The function and regulatory mechanism for the main four transcripts of dmrt1 in the sex differentiation and sex reversal in the rice field eel will be elucidated. Our findings will guide the exploration for gonad differentiation and development pattern of the rice field eel, then help to control the gonad development to get female eel parents with big body or mature male eel parents.