猪繁殖与呼吸综合征病毒HS株结构蛋白基因的克隆与序列分析

根据GenBank中猪繁殖与呼吸综合征病毒(PRRSV)美洲株(VR-2332)基因序列,设计合成了ORF2a、ORF3、ORF4、ORF5、ORF6和ORF7基因的引物.利用RT-PCR扩增出PRRSV HS株各基因的cDNA片段,将扩增的各cDNA片段克隆入pMD18-T载体并测序.应用DNA Man软件,将测序结果与国内外已发表野毒株和疫苗株(VR-2332、Resp MLV、16244B、HN1、BJ-4、CH1-a、HB-1、HB-2、LV)的相应基因进行序列比较,并绘制系统进化树.结果表明,PRRSV HS株与美洲型的相应基因核苷酸同源性为83.6%～99.7%,与LV株的相应基因核苷酸同源性为38.9%～49%;推导的氨基酸与美洲型相应基因的同源性为86.6%～99.6%,与LV株的同源性为54.2%～78.2%.系统进化树表明,PRRSV HS株属于美洲型,与HN1、VR-2332、RespMLV、16244B、BJ-4亲缘关系较近.

Cloning and Sequence Analysis of Structural Protein Genes of Porcine reproductive and respiratory syndrome virus HS Strain

ORF2a-ORF7 genes of porcine reproductive and respiratory syndrome virus(PRRSV) HS strain were obtained by RT-PCR and sequenced after being cloned directly into the pMD 18-T.The sequences of ORF2a-ORF7 genes of the isolate were compared with the sequences of other PRRSV strains in GenBank by DNAMAN software.The results showed that the ORF2a-ORF7 of the PRRSV HS strain shared 83.6%-99.7% of nucleotide homology and 86.6%-99.6% of amino acid homology with that of North American genotype(VR-2332,Resp MLV,16244B,HN1,BJ-4,CH1-a,HB-1,HB-2),respectively.And they shared only 38.9%-49% of nucleotide homology and 54.2%-78.2% of amino acid homology with that of LV,respectively.The phylogenetic trees revealed the PRRSV HS strain was clustered within North American genotype and had close relationship with HN1,VR-2332,RespMLV,16244B,BJ-4.