根据Ⅰ型鸭肝炎病毒(Duck hepatitis virus,DHV-Ⅰ)ZJ-Ⅴ株基因组序列(GenBank登录号:EF382778),设计了一对扩增RNA聚合酶基因(RNA-dependent RNA polymerase,RdRp)的特异性引物,以ZJ-Ⅴ株基因组为模板,扩增DHV-Ⅰ的RdRp基因。运用DNAStar软件对ZJ-Ⅴ株病毒与GenBank上已发表的其他不同DHV毒株的RdRp基因序列进行同源性比较和遗传进化分析,结果表明,ZJ-Ⅴ株与A型DHV-ⅠR85952株(DQ226541)的同源性为97.1%,亲缘关系最近,与2株台湾新型(B型)DHV之间为76.9%和77.0%,与C-GY株和4株韩国新型(C型)DHV株之间为76.2%~76.5%,亲缘关系较远。将RdRp基因克隆至原核表达载体pET-32a(+),获得重组表达质粒pET-RdRp,转化宿主菌E.coli BL21(DE3),用IPTG进行诱导表达。SDS-PAGE分析结果显示RdRp蛋白分子量约为65 kDa,Western blot检测证明RdRp蛋白能与Ⅰ型鸭病毒性肝炎阳性血清产生特异性免疫反应,具有良好的免疫学活性。本文为进一步研究DHV-Ⅰ的复制机理奠定了基础。
In this study,a pair of specific primer,according to the complete genomic sequence of duck hepatitis virus Ⅰ(DHV-Ⅰ) ZJ-Ⅴ strain,was designed to amplify RNA-dependent RNA polymerase gene(RdRp).Then the sequence of RdRp was compared with some reference sequences of DHV-I published in GenBank,and the results showed that ZJ-Ⅴ strain had closer genetic relationship with DHV-Ⅰgenotype A,compared with genotype B and C.To express RdRp in E.coli,RdRp gene was inserted into pET-32a(+) vector.And the recombinant plasmid pET-RdRp was transfected into BL21(DE3)cells.The expression product was analyzed with SDS-PAGE and Western blot.The results showed that RdRp was expressed successfully,about 65 kDa.The paper laid the foundation for further study on the replication mechanism of DHV-Ⅰ.