猪繁殖与呼吸综合征病毒TS株结构蛋白基因的克隆与变异分析

从河北唐山分离到一株疑似猪繁殖与呼吸综合征病毒(PRRSV),接种Marc-145细胞,经2代盲传后出现细胞病变,经鉴定为PRRSV,命名为TS株。利用RT-PCR扩增出TS株各基因的cDNA片段,然后克隆入pMD19-T载体并测序。应用DNAStar软件,结合其它河北毒株与多株GenBank中已发表的PRRSV毒株相应基因进行序列比较。结果表明:PRRSV TS株与VR-2332同源性为88.9%-94.7%,与河北省2007年以来发现的8个毒株同源性很强,为98.0%-99.7%;与LV株的亲缘关系较远,同源性为61.2%-69.0%,属于美洲型。遗传进化树表明国内美洲型分离株明显分为2个亚群,所有河北省流行毒株属于同一亚群,且TS株与高致病性代表毒株JXA1关系非常近。本研究将为河北省预防和控制PRRS提供重要的理论数据。

Cloning and Sequence Analysis of Structural Protein Genes of Porcine Reproductive and Respiratory Syndrome Virus TS Strain

The ORF2a-ORF7 genes of porcine reproductive and respiratory syndrome virus(PRRSV) TS strain isolated in our laboratory from Tangshan Hebei were obtained by RT-PCR and sequenced after being cloned directly into the pMD19-T.The sequences of ORF2a-ORF7 genes of the isolate were compared with the sequences of other PRRSV strains in GenBank by DNAStar software.The results showed that the ORF2a-ORF7 of the PRRSV TS strain shared 88.9%-94.7%of nucleotide homology with North American genotype(VR-2332) and highly homology with the strains isolated from Hebei province in recent years.But,they shared only 61.2%-69.0%of nucleotide homology with LV strain,and belong to American genotype.The phylogenetic trees revealed the domestic strains could be divided into two subgroups,the Hebei strains were clustered within one subgroup and had close relationship with highly pathogenic representative strain JXAl.This study will provide reference of PRRS prevention and control in Hebei province.