抗菌肽是无脊椎动物先天免疫系统中清除细菌、真菌的主要免疫效应分子，其产生过程受到多种信号通路的调节。目前，在抗菌肽发挥抗菌活性过程，关于抗菌功能与分子本身其他功能的协同作用机制的研究结果，以及抗菌肽分子抗菌活性与分子结构基序之间关联的研究结果，十分有限。因此，本课题进行淡水小龙虾抗菌肽基因的表达调控以及功能的系统研究，包括基因克隆、组织分布、病原刺激下的表达模式。在重组表达抗菌肽基因后，制备抗血清，从体内、体外研究基因的多种功能。同时，利用基因定点突变技术，研究决定抗菌肽分子抗菌活性的分子结构基序；并且，解析天然抗菌肽分子与突变分子的晶体结构，来探索分子结构基序与抗菌功能之间的关系。此外，重点研究在病毒刺激下，抗菌肽分子与抗病毒免疫反应之间的关联。本课题对于进一步完善无脊椎动物先天免疫系统基础理论，具有较大促进意义，对于水产类经济动物免疫防治策略的制定具有重要的理论促进和实践指导意义。

Antimicrobial peptides were the main effector molecules that involved in the clearance process of bacteria and fungi in invertebrate innate immune system. There were a lot of signal pathways which were involved in the antimicrobial peptides producing processes. At present, in the process of antimicrobial peptides exerting their antibacterial activities, the research results about the synergistic effect mechanism between antimicrobial function and other functions of the molecules themselves, and the research results about the relationship between antibacterial activity and antibacterial peptides molecular structure were very limited. In this project, the gene expression regulation and molecules function of antimicrobial peptides were systematically studied in Procambarus clarkii. The research contents included gene cloning, tissue distribution, the gene expression profile under the pathogens stimulation, and so on. The antiserum preparation, function research in vivo and vitro were done, after recombinant expression of antibacterial peptides genes was achieved. At the same time, the structural motif which could decide the antimicrobial activity was studied, using the site-directed mutagenesis technique. And the crystal structures of natural antimicrobial peptides and mutational molecules were analyzed to explore the relationship between molecular structure motif and function. In addition, the relationship between the antimicrobial peptides and antiviral immune response under viral stimulation was centrally studied. The results of this project has a great significance for further improvement of the invertebrate innate immunity system basal theory. And there are very important theoretical promotion and practical guiding significance to the immune prevention and control strategies for aquatic economical animal.