罗非鱼近缘种不同性别决定方式的分子进化机制研究

项目名称： 罗非鱼近缘种不同性别决定方式的分子进化机制研究

项目编号： No.91331119

项目类型： 重大研究计划

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 王德寿

作者单位： 西南大学

项目金额： 100万元

中文摘要： 近缘种尼罗罗非鱼和奥利亚罗非鱼分别采用XY和ZW两种性别决定类型。基于两者杂交后代可育的事实，我们认为性别决定类型的区分不是绝对的，亲本两套不同性别决定基因和调控网络存在协作机制，性别对抗性选择对于性别决定位点产生和快速固定有重要作用。杂交导致的基因渐渗可产生不可估量的基因组合和多态性，是对不可预测环境的投资，这在罗非鱼的快速分化和适应辐射过程中有重要作用。基于已公布的罗非鱼基因组序列，我们利用新一代测序技术测得两种罗非鱼以及它们杂交后代性别决定与分化关键时期性腺的20个（12个待测）转录组数据，寻找性别决定基因和下游调控网络，筛选性别特异、性别差异基因，分析它们以及类固醇合成酶基因的表达谱，从全基因组水平比较两种罗非鱼性别决定基因及其调控机制的差异，揭示性别对抗性选择和杂交引起的基因渐渗对于性别决定基因的进化、物种形成和适应辐射的作用，从而阐明罗非鱼近缘种不同性别决定方式的分子进化机制。

中文关键词： 近缘种；性别决定；性别决定方式转换；分子机制；

英文摘要： Sex is a special characteristics. Two closely related tilapiine species, Oreochromis niloticus and O. aureus adopted XY and ZW sex determination system, respectively. Based on the fact that interspecific hybridization between the two fishes produces fertile offspring, we propose that there are no absolute barriers between those two systems, instead, there is a coordination mechanism between the two different sex determining genes and regulating networks. Sexually antagonistic selection has critical roles in the recruitment and fixation of new sex determining locus. Introgression resulted from interspecific hybridization produces inestimable gene combinations and polymorphisms, which are investments to the indeterminate future environment, and therefore, is critical to the rapid divergence and adaptation of the tilapiines. In the present study, we intend to prove these hypotheses by making use of the completed 5 cichlid genome sequences, and the 20 gonad transcriptomes (12 to be sequenced) from the two species and their hybrids sampled at the critical period of tilapia sex determination and differentiation. We plan to screen their sex determining genes and regulating networks from the genome and transcriptome level, to select sex specific and sex biased genes and analyze the expression profile of these genes and

英文关键词： closely related species；sex determination；transition of sex determining system；molecular mechanisms；