【摘要】 为了给河北地区预防和控制猪繁殖与呼吸综合征(PRRS)提供理论数据,根据GenBank公布的多株PRRSV全基因序列,设计并合成3对特异性引物,应用RT-PCR方法分别扩增HB-3(cz)株、HB-4(hs)株的ORF5、ORF6、ORF7基因片段.分别将片段克隆入pGM-T载体后进行测序,并结合其他河北毒株与多株GenBank中PRRSV毒株ORF5～7基因序列进行比较.结果表明,河北省2007年以来发现的9个毒株序列同源性很强,与近年国内流行的毒株群相似性很高,达98.8%～99.5%,均属于美洲型;其主要结构蛋白E、M、N蛋白抗原表位区域极其类似;与前些年国内主要流行毒株群相似性较低,为91.9%～92.6%;遗传进化树分析表明国内美洲型分离株明显地分为2个亚群,河北省流行的毒株亲缘关系较近,在同一亚群内.更多还原

【Abstract】 Three pairs of primers were designed according to the published nucleotide sequences of porcine reproductive and respiratory syndrome virus(PRRSV) in GenBank,and to amplify complete ORF5-7 gene of PRRSV HB-3(cz),HB-4(hs) strains by RT-PCR.The PCR products were cloned into pGM-T vector.The recombinant plasmid were sequenced and compared with sequences of other PRRSV strains in GenBank.The results show that the 9 strains isolated from Hebei Province belonged to American genotype;the ORF5-7 gene of them have 98.8%-99.5% homologies in nucleotide level with the strains isolated from China in recent years,and the antigenic epitope regions of major structural protein were homologous;whereas it was only 91.9%-92.6% homologies with the strains isolated from China in last years.Phylogenetic tree analysis showed that the domestic strains could be divided into two subgroups according to the genetic distance,and the Hebei strains belonged to one subgroup.更多还原