雌核生殖银鲫雄性发生及性别分化机制研究

Studies on fish sex and the related fields are very important for illustrating the evolution of sex regulation mechanism in vertebrates. Gibel carp (Carassius gibelio) is a hexaploid fish with ability of unisexual gynogenesis, but rare male individuals have been observed in natural habitats. In previous study, we have isolated a male-specific molecular marker in the gibel carp, and revealed that the extra microchromosomes in males played male determination role. However, the mechanisms of male incidence and sex differentiation in gibel carp are still unclear. In this project, we will screen male determination related genes in gibel carp, via single chromosome fluorescence microdissection and sequencing of male-specific microchromosome. Subsequently, we will isolate sex differentiation related genes in gibel carp, through gonadal transcriptome analysis at different development stages during sex differentiation. And we will identify the biological functions of some potential male determination or sex differentiation genes, using the methods of transgene and gene knockout. Thus, this project will preliminary clarify mechanisms of male occurrence and sex regulation in the gynogenetic gibel carp, which will help us for further understanding male origin and evolution in vertebrates.

鱼类性别及相关研究对于解析脊椎动物性别调控机制的演化有重要意义。银鲫是一种行雌核生殖的多倍体鱼类，但在自然群体中却存在少部分雄性个体。前期研究工作中，我们筛选得到银鲫雄性特异分子标记，揭示了雄性个体中额外微小染色体具有雄性决定作用。然而，雌核生殖银鲫雄性发生及性别分化机制还不清楚。本项目拟通过单染色体荧光显微切割及雄性特异微小染色体测序，筛选银鲫雄性决定相关基因；利用雌雄性腺分化时期不同发育阶段转录组分析，筛选银鲫性别分化相关基因；通过转基因和基因敲除等技术，鉴定潜在雄性决定或性别分化基因的生物学功能。本项目将初步阐明雌核生殖银鲫雄性发生和性别调控机制，促进对脊椎动物雄性起源和进化的深入理解。

鱼类性别及相关研究对于解析脊椎动物性别决定和分化机制的演化有重要意义。银鲫是一种行雌核生殖的六倍体鱼类，但在自然群体中却存在少部分雄性个体。前期研究工作中，我们筛选得到银鲫雄性特异分子标记，揭示了雄性个体中额外微小染色体与银鲫雄性决定紧密关联。然而，雌核生殖银鲫雄性发生及性别分化机制还不清楚。本项目解析了银鲫雄性特异超数微小染色体的基因组，筛选到性别决定时期雄性特异或者雄性偏向表达的潜在性别决定相关基因；发现银鲫性腺芳香化酶基因cyp19a1a具有雌性分化作用，揭示了银鲫重复的gsdf基因（gsdf-A和gsdf-B）通过协同抑制cyp19a1a转录来调控雄性分化；证明遗传雄性能够产生雄性子代且增加子代遗传多样性，对于雌核生殖银鲫演化适应性有重要作用；揭示银鲫性别决定系统的转换与生殖方式的转变紧密关联，并利用雌核生殖六倍体银鲫和有性生殖四倍体鲫创制了具有有性生殖能力的合成八倍体。本项目初步解析雌核生殖银鲫雄性发生和性别分化机制，为单性脊椎动物性别演化提供了创新见解。