中文摘要：

为了探索猪繁殖与呼吸综合征病毒（PRRSV）强、弱毒株的Nsp9基因对PRRSV复制的影响,构建含有PRRSV XH-GD强毒株、CH-1R弱毒株Nsp9全长基因的质粒p IRes2-EGFP-Nsp9-XH-GD、p IRes2-EGFP-Nsp9-CH-1R,并将重组质粒分别转染到Marc-145细胞中,以MOI=1的剂量接种PRRSV XH-GD毒株,通过TCID50试验测定病毒的滴度,采用荧光定量PCR和Western Blot方法来测定病毒的N蛋白表达情况。结果表明,转染弱毒株CH-1R Nsp9基因的Marc-145细胞中,PRRSV的N蛋白在mRNA水平、蛋白质水平上的表达量均高于转染强毒株XH-GD组,且病毒的滴度也显著高于转染强毒株XH-GD组。综上,在Marc-145细胞中,弱毒株CH-1R Nsp9基因对PRRSV复制的促进作用优于强毒株XH-GD。

英文摘要：

In order to verify the difference of gene Nsp9 between virulent strain and low virulent strain whether could enchance the replication of PRRSV, plasmids pIRes2-EGFP-Nsp9-XH-GD and pIRes2-EGFP-Nsp9-CH-1R containing whole Nsp9 genome were transfected into Marc-145 cells,qPCR and Western Blot were conducted to e- valuate its titer and expression after PRRSV was inoculated, the results showed that the level of N protein in the cells that were transfected with low virulent strain CH-1R Nsp9 gene was higher than the control group-virulent strain XH-GD in the mRNA level. Meanwhile, on the protein level, it was the same as the mRNA level, and virus titer was also higher than virulent strain. It demonstrated that Nsp9 gene of low virulent strain CH-1R in the Marc- 145 cells was more beneficial to the replication of PRRSV than that of virulent strain XH-GD.