犬瘟热病毒H基因的序列分析

Genetic analysis of Hgene of canine distemper virus

【目的】探索犬瘟热病毒(Canine distemper virus,CDV)基因的遗传变异情况,为CDV的防控提供理论依据。【方法】收集2014-2015年流行于上海和安徽两地的CDV野毒株,用RT-PCR方法克隆其血球凝集素蛋白基因(H),从分子水平上讨论CDV H基因的流行规律、遗传进化特性和变异情况。【结果】分离的5株CDV之间H基因核苷酸和氨基酸序列的同源性分别为97.5%~99.9%和97.5%~99.2%,其与CDV疫苗株CDV3和Onderstepoort H基因核苷酸的同源性为90.9%~99.9%,氨基酸的同源性为90.4%~99.6%。进化树分析结果表明,分离到的5株CDV野毒株均属于亚洲Ⅰ型,与大部分的亚洲Ⅰ型处于同一分支。CDV H基因有9处潜在的天冬氨酸糖基化位点;H基因整体的同义突变概率与非同义突变概率的比例,即ds/dn=5.887 0。【结论】选择压力并未作用于分离到的CDV毒株,而是在中性选择作用下进化的。

【Objective】This article discussed the genetic characteristics and regularity of H gene from canine distemper virus（CDV）in molecular level.【Method】CDV strains from Shanghai and Anhui in2014-2015 were collected and their H genes were cloned by RT-PCT.Then,the regularity and genetic characteristics were analyzed in molecular level.【Result】The nucleotide and amino acid similarities of H gene between the 5wild strains were 97.5%-99.9% and 97.5%-99.2%,respectively.The nucleotide and amino acid similarities of H gene between the 5 wild strains and vaccine strains CDV3 and Onderstepoort were 90.9%-99.9% and 90.4%-99.6%.Phylogeny tree showed that the collected 5CDV lineage belonged to Asia-Ⅰ,like most of the other H protein genes of Asia-Ⅰ.There are 9potential N-glycosylation sites and ds/dnratio was 5.887 0.【Conclusion】The selection process did not affect isolated CDV stains and the evolution occurred with a neutral evolution pattern.