免疫抗体压力下PRRSV GD株Nsp2和GP5基因变异分析

Variation Analysis of the Nsp2 and GP5 Gene of PRRSV(GD strain) under Antibody Selective Pressures

以PRRSV GD-2007株为材料,在自然条件和抗体压力下连续传至40代后,分别命名为PRRSV-GD-f 40和PRRSV-GDAb-f 40,进行RT-PCR,扩增Ns p2基因部分序列和GP5基因全长,克隆并测序。应用序列分析软件将测序结果和已经发表的PRRSV毒株进行比对,结果显示:Nsp2基因扩增片段大小均为796 bp,自然传代和抗体压力下传代后的新毒株和母源毒株的相似性分别为98.0%和97.9%;扩增的GP5基因大小为603 bp,编码200个氨基酸,和母源毒株的相似性分别为99.2%和98.8%。

PRRSV strain GD was continuously propagated in Marc-145 cells for 40 passages without PRRSV antibody or with PRRSV antibody and the viruses after passages were named RRRSV-GD-f40 or RRRSV-GDAb-f40 respectively. Nsp2 and GP5 genes were cloned and sequenced. Comparison results showed that the amplification fragment of Nsp2 gene of all isolates were 796 bp long and shared 98.0% or 97.9% similirities with maternal strain respectively. The GP5 genome analyses showed that their cDNAs of GP5 were 603bp long and shared 99.2% or 98.8% similirities with maternal strain respectively.