猪圆环病毒Ⅱ型ZZ株ORF2基因的扩增、测序与序列分析

Amplification,Sequencing and Sequence Analysis of ORF2 Gene of PCV Ⅱ in ZZ Strain

扩增PCV-2 ZZ毒株ORF2基因,并进行序列分析和同源比较。根据GenBank中PCV-2毒株基因序列设计1对特异性引物,对郑州分离株（ZZ）猪圆环病毒PCV-2型的ORF2基因进行了扩增。测序后,将所测序列与已公布的PCV-2 ORF2序列进行同源性比较,并绘制系统发育进化树。通过扩增可获得702 bp的PCV-2 ORF2全基因,编码234个氨基酸,分子量27 995.93 D。所有毒株间的ORF2基因核苷酸同源性与氨基酸同源性均为89.2%-100%;ZZ株与HZ0201分离株的ORF2基因的核苷酸序列同源性较近（98.3%）,而与hk102同源性较远（92.0%）。进化树分析表明,各分离毒株在进化上地理位置的相关性不明显。该研究对圆环病毒的流行病学和疫苗研究及其抗原的变异都具有重要参考价值。

The aim of the research was to amplify ORV2 gene of PCV Ⅱ in ZZ strain and make sequence analysis and homology comparison. Aeeording to the sequence of PCV-2 gene in virus strain on GenBank website, a pair of specific primers were designed to amplify ORF2 gene of PCV Ⅱ in Zhengzbou isolated strain （ZZ）. After sequencing, the homology comparison was conducted on measured sequence and the published ORF2 sequence of PCV-2 gene and the phylogenetie tree was drawn. The whole ORF2 gene of PCV-2 of 702 bp was obtained through amplification, 234 amino acids were ceded and molecular weight was 27 995.93 D. Homology of nueleetide and amino acid in ORF gene among all virus strains both were 89.2% - 100%. The homology of nueleetide sequence in ORF gene between ZZ strain and HZ0201 isolated strain was closer, being 98.3% and that with hk102 strain was farther, being 92.0%. The analysis of phylogenetie tree indicated that the relativity of geogiaphical position on evolution among isolated strains was not obvious. The research had important reference values for studying the epidemiology and vaccine of eireovirus and its antigen aberrance.