草鱼抗GCRV主效功能分子筛选及其遗传机制解析

草鱼是我国养殖产量最大的淡水鱼类，但草鱼呼肠孤病毒（GCRV）引起的出血病长期制约其健康发展。基于抗GCRV先天免疫特性开展草鱼抗病育种是解决这一难题的重要手段，本项目基于团队已有的草鱼和赤眼鳟全基因组数据，结合前期发现多个先天免疫通路和功能分子（C3、C1q4、C9补体凝血级联、TLR-IRF干扰素调控等）与GCRV抗性显著相关的研究基础，拟以赤眼鳟、草鱼与赤眼鳟杂交F1、母源免疫草鱼及不同水系原种草鱼为材料，通过多组学高通量测序进一步系统筛选鉴定抗GCRV免疫通路和分子；利用过表达、RNA干扰、基因编辑、免疫共沉淀、双分子荧光互补、磷酸化和泛素化检测等技术解析抗GCRV免疫分子的遗传特性及功能机制，发掘GCRV抗性功能明显和遗传关联性强的主效抗性分子；并在三大水系原种草鱼群体中开展抗病亲本筛选和家系选育，创制GCRV抗病抗逆草鱼新材料，奠定抗病草鱼分子设计育种的材料、理论和技术基础。

Grass carp (Ctenopharyngodon idellus) is the largest cultured freshwater fish in China, while the healthy development of grass carp industry is long-term restricted by grass carp hemorrhage disease caused by GCRV (grass carp reovirus) infection. The development of new breeding techniques based on innate immune molecules with high GCRV resistance is becoming urgent to solve the problem. Our previous study from C. idellus and barbel chub (Squaliobarbus curriculus) suggests complement and coagulation cascade related molecules (C3, C1q4 and C9) and TLR-IRF interferon signaling are promising GCRV resistance candidate pathways and molecules. In this proposed project, using different populations of wild C. idellus, S. curriculus, hybrid F1 progeny from C. idellus and S. curriculus, and maternal immunized C. idellus progeny as the research materials, we will conduct multi-omics high-throughput sequencing technology to comprehensively screen and verify GCRV resistance candidate pathways and molecules based on the sequenced genomes of C. idellus and S. curriculus. We will utilize over-expression, RNA interference, gene editing, co-immunoprecipitation, bimolecular fluorescence complementation, phosphorylation and ubiquitination detection tools to dissect the immune regulation and hereditary mechanism of GCRV key resistance molecules, which show strong disease resistance and genetic association in different strains of C. idellus. Lastly, we will perform molecular marker assisted breeding to test the breeding potential of GCRV key resistance molecules in the three major families of wild C. idellus in China. Our findings will develop new C. idellus sources with GCRV resistant, and lay a material, theoretical and technical foundation for the molecular design breeding of disease-resistant grass carp.