猪繁殖呼吸综合症(PRRS)是由PRRS病毒（PRRSV）感染引起的危害大和防治难的世界性传染病，目前仍缺乏安全有效的疫苗药物和技术。本项目将（1）构建猪源全基因组靶基因gRNA文库和利用全基因组基因敲除编辑Genome-Wide CRISPR-Cas9技术，在猪全基因组中筛选PRRSV感染相关候选基因；（2）构建猪单个特定基因gRNA表达载体和利用单个特定基因敲除编辑CRISPR-Cas9技术，鉴定感染候选基因在PRRSV增殖感染中作用，挖掘PRRSV感染相关猪重要基因；（3）利用CRISPR-Cas9等技术研究该重要基因对PRRSV增殖感染的作用机理，为研究PRRSV致病、猪免疫抗病等机理奠定基础，为防治PRRS新型疫苗药物的研制、通过敲除或修饰感染相关猪重要基因的策略培育抗病新品种等提供参考，将具有重要的理论和应用价值。

Porcine Reproductive and Respiratory Syndrome (PRRS) that is caused by PRRS virus (PRRSV) is worldwide serious infectious diseases, and results in huge economic loss and difficulties of prevention and control, is therefore the industry leading killer. Due to the complex immunological characteristics of the PRRSV constantly variation and suppression of pig immune response, these increase the difficulties to investigate the PRRSV pathogenic mechanism and the porcine immune antiviral mechanism, so that it is still lack of effective security vaccines and drugs and techniques. ..This project will (1) establish the pig Genome-Wide gRNA library and use the Genome-Wide CRISPR-CAS9 technique to knockout genome-wide genes, to screen and select the candidate genes related with PRRSV-infection based on pig whole genome; (2) establish the pig targeted gene gRNA vector and apply the CRISPR-CAS9 tool that knockouts a single specific gene, to study the roles of candidate genes on PRRSV proliferation and infection, and then identify the pig important genes related PRRSV proliferation and infection; and (3) investigate the mechanisms of pig important genes on PRRSV proliferation and infection using CRISPR-CAS9. ..The results obtained from this project will contribute to the development of the new types of vaccines and drugs to prevent and control PRRS, and to breeding disease-resistance pigs through the important genetic strategy that knockout or modify the pig important genes related with PRRSV proliferation and infection, and also enhance to better understand the PRRSV pathogenic mechanism and porcine immune antiviral mechanism, so this project will have important applied and theoretical value.