2006～2008年重庆部分区县PRRSV分离株ORF5和Nsp2基因的遗传变异分析  

Analyses of genetic variation in Nsp2 and ORF5 genes of porcine reproductive and respiratory syndrome virus strains in some counties of Chongqing Municipality from 2006 to 2008

作　　者：高君[1] 冉智光[2] 谭世君[2] 汤明[1] 曾政[2] 杨泽林[2] 米自由 熊仲良[2] 

机构地区：[1]西南大学动物科技学院,重庆400716 [2]重庆市动物疫病预防控制中心,重庆401147

出　　处：《中国兽医科学》2009年第7期580-586,共7页Chinese Veterinary Science

基　　金：重庆市科技攻关项目(2009AC1111)

摘　　要：为了解重庆市PRRSV流行毒株的遗传变异情况和分子流行病学背景,对2006-2008年分离到的14株重庆市内的PRRSV流行毒株进行了Nsp2和ORF5基因序列的测定和分析。结果显示,与2006年以来国内流行的变异毒株相比,Nsp2与ORF5基因的核苷酸同源性分别达到97.3%-99.5%和98.2%-99.7%,这2个基因推导的氨基酸序列同源性分别达到95.7%-99.2%和98.0%-99.5%。与传统毒株相比,Nsp2和ORF5基因及其推导的氨基酸都存在点突变,并在Nsp2基因内部存在编码30个氨基酸的碱基对的不连续缺失,ORF5基因未存在缺失。从遗传进化以及变异情况看,重庆市流行的PRRSV主要为变异毒株,属于美洲型中的亚群Ⅱ。To understand the molecular epidemiology of prevalent porcine reproductive and respiratory syndrome virus（PRRSV） in Chongqing Municipality,the Nsp2 and ORF5 genes of 14 Chongqing strains of PRRSV collected between 2006 to 2008 were amplified by RT-PCR and sequenced. By comparing these sequences with Chinese PRRSV strains published after 2006,Nsp2 gene shared 97.3% to 99.5% of nucleotide homologies and 95.7% to 99.2%of the deduced amino acid homologies, and the ORF5 gene shared 98.2% to 99.7% of nucleotide homologies and from 98.0% to 99.5% of the deduced amino acid homologies. Compared with classical PRRSV strains,Nsp2 gene of the Chongqing strains resulted in 30 discontinuous amino acid deletions and some site mutations,and the ORF5 gene had a few site mutations but no deletion. The phylogenetic tree indicated that PRRSV Chongqing strains might be mutant strains, and were classified into subtype Ⅱ of North American type.

关 键 词：猪生殖与呼吸综合征病毒 NSP2基因 ORF5基因 遗传变异 

分 类 号：S852.659.6[农业科学—基础兽医学] Q503[农业科学—兽医学]