Ⅰ型鸭肝炎病毒SN株和弱毒疫苗株全基因组克隆及序列分析

Molecular cloning and sequence analysis of complete genome of DHV-Ⅰ SN strain and attenuated vaccine strain

根据Ⅰ型鸭肝炎病毒(DHV-Ⅰ)基因组序列设计并合成引物,通过RT-PCR方法对鸭肝炎病毒SN株和弱毒疫苗株全基因分段扩增并克隆测序。比较分析SN株、弱毒疫苗株和参考毒株多聚蛋白基因和VP1基因核苷酸序列构建系统进化树。结果表明,所测定的2个毒株多聚蛋白基因核苷酸序列与DHV-Ⅰ型GFS99广东株相似性最高(99.5%)。DHV-ⅠVP1基因核苷酸序列系统进化树分为3个群:SN株在以韩国强毒株R85952为代表的强毒株群中,弱毒疫苗株在以A66为代表的弱毒株群中,另外一群是以SY1为代表的从浙江分离的强毒株。

The genome sequences of duck hepatitis virus type1（DHV-1） SN strain and attenuated vaccine strain were amplified by RT-PCR with the primers designed according to the conserved region of DHV-1 genome.The sequence of polyprotein gene and VP1 gene were analyzed by DNAStar software and the phylogenetic trees were constructed.The results showed that the two strains had closest relationship with DHV I GFS99 strain sharing 99.5% identity.Phylogenetic tree analysis of VP1 showed that all DHV-1 strains could be classified into three distinct genetic subgroups： SN strain was genetically close to R85952 virulent reference strain could be classified as subgroup;the attenuated vaccine strain was closer with low virulent A66 strain,which were classified as subgroup Ⅱ,and the SY1 virulent reference strain which isolated from Zhejiang belong to the subgroup Ⅲ.