拟穴青蟹雌雄间在生长速度、个体大小、营养价值等方面存在明显差异，是单性养殖的潜在品种。但目前关于性别间遗传差异的研究甚少，尚不清楚其性别决定类型，这严重制约了性别控制及单性育种研究的开展。本项目拟在已筛选到性别连锁标记和性别相关基因的基础上，采用分子和细胞生物学技术探究拟穴青蟹染色体性别决定机制。首先利用基因分型技术阐明性别连锁标记在全同胞家系世代间的遗传规律，结合基因组框架图深入挖掘性别相关基因；然后运用遗传作图技术在高密度图谱中定位性别决定区、性别连锁标记和性别相关基因，弄清它们的分布特征及连锁关系，鉴定出性别相关连锁群；最后通过核型分析和FISH技术，揭示出性别决定区、性别连锁标记和性别相关基因在染色体上的定位规律，鉴定出性别相关染色体及对应的连锁群，从而深入阐明染色体性别决定机制。本项目将深化对海洋蟹类性别决定机制的认识，为开展性逆转、性别控制及单性育种研究提供理论依据和技术支撑。

The mud crab Scylla paramamosain has a big potential for unisexual culture, because the females have many advantages than the males, such as faster growth rate, bigger body size, and higher nutritional value. However, little information could be available for the genetic differences between sexes, and what’s more, the sex determination system is still unknown that has severely limited the studies on sex control and unisexual breeding. In our previous study, sex linked SNP molecular markers and sex associated genes were obtained. Here we plan to further discover the chromosome sex determination system of S. paramamosain using molecular and cell biology technology. Firstly, we will illuminate the inheritance pattern of sex linked markers in full-sib families by genotyping technology, and deeply isolate sex associated genes based on recently completed draft genome. Secondly, we will construct high-density genetic linkage maps, map the sex determination region, sex linked markers, and sex associated genes, and identify the sex related linkage group. Finally, we will reveal the mapping characteristics of sex linked markers and sex associated genes on chromosomes using FISH technology, and further distinguish the sex related chromosome and clarify the chromosome sex determination system. This study will provide new insights into sex determination system of marine crabs, and facilitate the studies on sex reversal, sex control, and unisexual breeding.