猪繁殖与呼吸综合征病毒7个分离株全基因序列测定及遗传进化分析

Genomic sequencing and analysis of the variations of 7 porcine reproductive and respiratory syndrome virus isolates

为了解猪繁殖与呼吸综合征病毒(PRRSV)的变异情况,本研究利用RT-PCR方法对2006年～2009年在我国部分地区分离鉴定的7株PRRSV分别进行9段基因片段扩增,测序分析表明,获得的病毒全基因序列与PRRSV JXA1变异株高度同源。并与GenBank中登录的其他70株PRRSV全基因序列进行遗传分析,根据构建的遗传进化树分析表明,中国大陆PRRSV分离株包含美洲型和欧洲型,美洲型可分为3个亚群,亚群1主要为以JXA1株为代表的病毒株,本研究中的7个分离株均为亚群1,其GP5主要中和抗原表位高度变异;亚群2主要为以CH-1a株为代表的病毒株;亚群3主要为以VR-2332株为代表的病毒株。欧洲型病毒株BJEU06-1、NMEU09-1分属于不同亚型。本实验为深入研究该病毒的遗传与变异及其分子流行病学研究奠定基础。

To investigate the variations of porcine reproductive and respiratory syndrome virus （PRRSV）, the whole genomes of 7 PRRSVs isolated during 2006 to 2009 were amplified by RT-PCR and sequenced. The complete genomic analysis indicated that the 7 PRRSV isolates （EF517962, EU825723, EU825724, HQ843178, HQ843179, HQ843180, HQ843181） were high homology with PRRSV JXA1 strain. The cladogram demonstrated that the PRRSVs isolated in mainland of Chinese were belonged to North American （NA） type and Europen （EU） genotype compared with 70 PRRSV reference strains in GenBank. Three highly diverse subgroups were clearly divided in the NA-genotype. PRRSV JXAI, CH-la and VR-2332 strains were of the representation of subgroup 1, subgroup 2, subgroup 3, respectively. BJEU06-1, NMEU09-1 of EU-genotype strains were belonged to a different branch. The 7 isolates were all classified in subgroup 1. Our date in this study would be useful to further investigate the genomic variation and molecular epidemiology of PRRSV.