甘肃犬瘟热病毒流行株N蛋白和H蛋白基因的序列分析

Sequence analysis of nucleoprotein and hemagglutinin genes of wild type canine distemper virus isolated from dogs in Gansu Province

采用RT-PCR方法扩增了3株犬瘟热病毒(CDV)分离株的N、H蛋白基因,将其克隆入pGEM-T Easy载体并进行序列分析。结果表明,获得的N蛋白基因序列与GenBank上登录的其他国家和地区的CDV分离株相应序列的同源性为92.5%～99.9%,获得的H蛋白基因与其他国家和地区的CDV分离株相应序列的同源性为81.7%～100%。由N蛋白基因和H蛋白基因推导的氨基酸序列构建的遗传进化树可知,这3株CDV流行株均处于野毒株的分支上,在N蛋白基因的遗传进化树上,CDV流行株呈现明显的地域性差异,而在H蛋白基因的遗传进化树上,不同国家和地区的CDV分离株之间虽有一定的地域联系,但与N蛋白基因相比,其地域性联系并不明显。说明这3株CDV流行株为野毒株,H蛋白基因的变异水平明显高于N蛋白基因,而N蛋白基因更能显示毒株与地域的关系。

The nucleoprotein（N） gene and hemagglutinin（H） gene were amplified from 3 strains of canine distemper virus（CDV） isolated from dogs in Gansu Province by RT-PCR.Subsequently,the nucleotides of these two genes were sequenced and analyzed by Clustal V of DNAstar.The N gene shared from 92.5% to 99.9% homology with those of the CDV strains available in GenBank.The H gene shared from 81.7% to 100% homology with those of the CDV strains from other regions.The phylogenetic tree based on the amino acid sequences deduced from the nucleotides sequences of the N gene indicated that the strains of CDV had remarkable difference and characteristics among different regions,but the phylogenetic tree based on the deduced H protein＇s amino acid sequences showed that the CDV strains were not different among the different regions.The above results showed that the 3 CDV strains from Gansu were classified as wild type.The mutations in H gene were more than that in N gene and N gene were able to display the relationship between CDV strain and region.