鱼类性别是由遗传和环境共同决定的，温度是影响性别分化最重要的环境因子之一。以往研究主要从下丘脑-垂体-性腺轴解释高温诱导鱼类雄性化机理。近年模式鱼类的研究显示原始生殖细胞（PGCs）在性别分化过程中起重要作用。高温是否会影响鲆鲽鱼类PGCs迁移、增殖？高温作用下生殖细胞形态结构、数量增殖及相关基因表达如何变化？生殖细胞与周围体细胞如何互作诱导协同分化为精巢？等一系列问题都需深入探索。该项目拟采用牙鲆遗传全雌家系（XX）为研究对象，从胚胎、仔鱼期PGCs的迁移、增殖变化；性别分化关键期生殖细胞与周围体细胞形态结构、数量及相关的基因的表达和互作等方面，并结合内分泌系统调控通路系统揭示高温作用下生殖细胞与体细胞发育与分化规律，以期从组织、细胞及分子发育生物学的视角阐明高温影响牙鲆PGCs发育及雄性化的机理，完善鱼类性别分化基础理论及生殖发育调控机制，并为揭示全球变暖导致海鱼生态结构变化积累资料。

Sex determination of fish is dependent on both genetic and environmental factors. In fish, temperature is one of the most important sex-determination factors. Previous studies about the mechanism of masculinization effect of high temperature on flatfishes mainly focused on the the hypothalamic-pituitary-gonadal axis. Recently, it has been demonstrated that the primordial germ cells (PGCs) play important role in sex determination in model fish species. PGCs-ablated fishes develop as sterile males. Thus, questions associated with the effect of high temperature on germ cells need to answer, including： The effect of high temperature on migration and proliferation of PGCs in flatfishes; The changes in morphology, number and the gene expression of germ cells during sex differentiation under high temperature;The interaction between germ cells and somatic cells under high temperature, which results in the formation of testis. This project will take genetic female olive flounder (Paralichthys olivaceus) (XX) under high temperature treatment as the research object. Systematical investigations on: 1) the migration and proliferation of PGCs; 2) dynamic changes in the number, morphology and gene expression; 3) endocrinological pathway, will be carried out to reveal the development process of germ cells and somatic cells and elucidate the the mechnism of masculinization under high temperature. The resluts of this project will enrich the basic knowledge of fish sex differentiation,improve the regulation mechanism of reproduction and development in flatshes and provide valuable information for research on ecological structure changes of marine fishes under global warming.