辽宁地区猪繁殖与呼吸综合征病毒分离株ORF5基因的遗传变异分析

为研究辽宁地区猪繁殖与呼吸综合征病毒(PRRSV)ORF5基因的生物学特性及遗传变异情况,通过RT-PCR方法对PRRSV阳性样品的ORF5基因进行扩增,应用DNA Star软件对检测的序列进行比对和遗传变异分析。结果显示,分离的8株PRRSV的ORF5基因全长为603 bp,均属北美型,不同分离株间的核苷酸、氨基酸同源性分别为91.5%~99.0%、88.1%~98.5%;遗传变异分析表明,分离株处于不同的进化分支,但均属于亚群3,为高致病性PRRSV。以上结果表明,辽宁地区主要流行毒株为高致病性PRRSV,在不同地区有不同的PRRSV毒株同时流行,但具有相同的进化来源。

Genetic Variation Analysis of ORF5 Gene of PRRSV Isolates in Liaoning Area

In order to study the biological characteristics and the genetic variation of porcine reproductive and respiratory syndrome virus(PRRSV) ORF5 gene in Liaoning area between 2014 and 2015,the full sequence of PRRSV ORF5 gene was amplified by RT-PCR from the PRRSV positive swine,and the sequence alignment and genetic variation analysis were conducted by DNA Star.The results showed that the ORF5 gene of 8 PRRSV strains was 603 bp,which belonged to the American mutant strain.Compared with representative strains,the nucleotide and amino acid homology were 91.5％ to 99.0％ and 88.1％ to 98.5％,respectively.The genetic variation analysis suggested that the isolated strains were in different branches of evolution,but they were located in the subgroup 3.These results indicated that the main epidemic strain in Liaoning area between 2014 and 2015 was the highly pathogenic PRRSV,and various PRRSV strains existed in different regions of Liaoning at the same time,which had the same evolutionary origin.