草鱼是我国的“四大家鱼”之一，养殖产量常年占据我国首位。然而，草鱼极易感染由草鱼呼肠孤病毒GCRV引起的出血病，死亡率可高达80%，对草鱼养殖业危害极大。根据GCRV的温度依赖性、发病快的特点，前期我们构建出新型衣壳蛋白靶向灭活转基因草鱼，通过GCRV攻毒实验，获得了抗病毒草鱼模型，发现转THVS阳性草鱼的抗病毒能力出现了分化，我们发现这种分化是由THVS插入位点多态性引起的。本申请项目拟针对不同抗病力的转基因草鱼，在基因、胚胎及个体层面验证THVS系统的插入位点多态性及其表达特征。利用高通量测序技术，建立不同抗病力草鱼的THVS插入位点数据库，通过“插入位点--抗病力”关联分析，以及插入基因和插入位点上下游关联基因的表达活性分析；最终，捕获完全抗病相关的关键插入位点，揭示THVS插入多态性及其关联基因与草鱼抗出血病能力的关系，为抗出血病草鱼模型的建立奠定基础。

Grass carp is one of the “four major Chinese carps” in our country, and its yield occupies the first place in China for many years. However, grass carp is easy to be infected with haemorrhagic disease caused by GCRV. The mortality rate can be as high as 80%, which is very harmful to grass carp. According to the characteristics of GCRV’s temperature dependence and fast onset, we constructed a innovative capsid protein targeting inactivated transgenic grass carp in the early stage. Through GCRV infection experiment, we obtained an antiviral grass carp model, and found that the antiviral ability of THVS-positive grass carp was differentiated. We found that this differentiation was caused by the polymorphism of THVS insertion site . The application project intends to verify the insertion site polymorphism and expression characteristics of THVS system at gene, embryo and individual levels for transgenic grass carp with different GCRV resistance. By using high-throughput sequencing technology, the database of THVS insertion sites of grass carp with different GCRV resistance was established. Through "insertion site and resistance" association analysis, as well as the expression activity analysis of insertion genes and upstream or downstream genes of insertion sites, and the key insertion sites related to complete anti GCRV were captured. Finally, the relationship between the insertion polymorphism and related genes of THVS and the resistance of grass carp to haemorrhagic disease was revealed. It laid a foundation for the establishment of the model of grass carp resistant to haemorrhagic disease.