我国部分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

参考Genbank发表的猪繁殖与呼吸综合征病毒（PKRSV）ATCC VR-2332的ORF5基因序列，设计并合成了一对引物．对来自福建、浙江、山东等地的PRRSV分离毒株进行RT-PCR扩增．获得约748bp的DNA片断，将其分别克隆入pMD18-T载体中，并进行测序。应用DNAStar软件分析所测序列，并与ATCCVR-2332、CH-1a、MLV、Lv等毒株的ORF5序列进行比较，结果表明：SHDl与F114、MLV、ATCCVR-2332同源性高达98．5％，与CH-1a同源性为91．0％，与其它毒株同源性为86．6％~88．4％；F114与MLV、ATCCVR-2332同源性为99．3％～99．7％．其余分离毒株在遗传关系上和CH-1a又分为明显的两个群．显示近年来各地PRRSV分离毒株与cH-1a株的遗传差异越来越大。

Analysis in Heredity and Variation of OPF 5 Genome Sequence of Wild Isolates of PRRS Viru sfrom Different Regions in China

According to the sequence of ATCC VR-2332 strain of porcine reproductive and respiratory syndrome virus published by the Genbank, a pair of primers was designed for RT-PCR amplification of PRRSV isolates from Fujian,Zhejiang and Shandong, obtaining DNA fragment of about 748bp, which were cloned into pMD18-T vector respectively and sequenced. The sequences of ORF5 genes were analysed using DNA Star and compared with those of ATCC VR-2332,CH-la,MLV and LV strains,indicating that the homology was up-to 98.5 between SHD1 and FJ14, MLV, ATCC VR2332, 91.0% between SHD1 and CH-la and 86.6%-88.4% between SHD1 and other strains; 99.3%-99.7% between FJ14 and MLV,ATCC VR-2332.And the other isolates and CH-la were two distinct genetically. It is suggested that recent isolates of PRRSV are becoming move different from CH-la genetically.