半滑舌鳎是我国鲆鲽鱼类主要养殖品种之一和理想模式鱼类，其主要病原鳗弧菌对养殖业可持续发展造成严重威胁，因为对半滑舌鳎的抗菌免疫防御机理不清楚，缺乏有效防治措施。在前期研究获得的“补体信号通路是抗鳗弧菌感染关键因素”基础上，本研究拟开展半滑舌鳎补体信号通路3个途径的基因鉴定、鳗弧菌感染后易感组、抗感组和对照组中免疫组织基因表达谱、蛋白表达谱及差异表达分析，筛选出各途径中关键补体基因；对关键基因进行组织时空定量表达分析；并通过过表达、RNA干扰、免疫共沉淀在细胞系中进行体外功能分析、结合重组蛋白在鱼体内不同感染状态下对关键基因表达的影响进行体内功能分析，从基因-基因、基因-蛋白及蛋白-蛋白层面揭示半滑舌鳎补体信号通路关键基因在病原识别、信号传递和病原清理阶段的抗菌感染免疫防御机理，绘制出组成清晰、功能明确的补体信号通路。丰富鱼类分子免疫理论，并为产业上防治细菌性疾病提供理论和技术支撑。

Half-smooth tongue sole (Cynoglossus semilaevis) is an important mariculture fish species in China, also a long-standing research model for basic research in flat fish. Recently, its cultivation has been severely threatened by Vibrio anguillarum, however, the fundamental molecular mechanisms of the antibacterial immune defense remain unclear in C. semilaevis. Our early studies have revealed that the complement singling pathway may play vital roles in antibacterial immune defense. Here, in this project, we will identify the complement genes based on both the transcriptome data obtained in our early research and gene cloning method, conduct Digital Gene Expression (DGE) and isobaric Tag for Relative and Absolute Quantitation (iTRAQ) and analysis gene differential expression profiling in immune tissues among the control group, the susceptible group and the resistant group, then find the candidate key complement genes. QPCR is utilized to determine their temporal and spatial expression patterns in tissue with V. anguillarum infection; and gene in vivo, in vitro functional verification will be performed by overexpression, RNAi, gene recombination and gene protein interaction; by co-immunoprecipitation (CoIP) and chromatin immunoprecipitation assay (ChIP) to verify the function of the complement proteins and interaction networks, to understand the mechanisms of antibacterial immune defense singling pathways in pathogen recognition, signal transmission and pathogen cleanup in C. semilaevis. Taken together, our results will expand our knowledge of molecular immunology in C. semilaevis, set foundation and provide technical support for prevention and control the bacterial diseases, such as V. anguillarum in aquaculture.