中文摘要：

在现在的学习， 89 猪的繁殖、呼吸的症候群病毒(PRRSV ) 在 2007 ～ 2012 期间在中国孤立随机从 GenBank 基因顺序数据库被选择。这些的进化特征孤立基于非结构的蛋白质的序列被分析 2 (Nsp2 ) 并且 glycoprotein 5 (GP5 ) 。isolates 的基因变化也与六代表性的紧张相比。结果证明基因差异的高度在中国在 PRRSV 人口之中存在。高度病原的 PRRSV 孤立，与在 Nsp2 区域的 30 氨基酸残余的不连续的删除，在中国在整个 20072012 仍然是最主导的病毒。由于代表性的疫苗的紧张的广泛的使用，自然再结合事件发生在紧张之间。三孤立 HH08， DY，和 YN-2011 比其它孤立的与疫苗的紧张有关仔细是更多。YN-2011 和 DY 是在紧张 SP 和 CH-1R 之间的再结合事件的进化产品。现在的学习的结果为 PRRSV 的传染病学以及为疫苗的开发提供有用信息。

英文摘要：

In the present study, 89 porcine reproductive and respiratory syndrome virus（PRRSV） isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2（Nsp2） and glycoprotein 5（GP5）. The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.