上海市伪狂犬病病毒相关毒力基因分子变异分析

为了解伪狂犬病病毒(pseudorabies virus,PRV)4种主要毒力基因(gB、gC、gD和gE)的分子特征和变异情况,采用PCR技术,对2010—2015年分离到的28株PRV进行基因扩增和测序。结果显示:2010—2015年分离毒株的gB、gC、gD和gE基因均存在多位点突变,且位于抗原表位区;与2010年分离毒株的gD基因相比,2012年后分离毒株存在6个连续氨基酸插入。基于gB、gC、gD和gE基因的进化树显示:上海市2010年分离的4个毒株与2012年以后分离的毒株虽属于同一大的分支,但与经典毒株亲缘关系近,处于同一小的分支中;2012年分离毒株与2011年后国内变异株亲缘关系近,处于另一分支中。这些毒力基因抗原表位区域氨基酸的突变可能导致其毒力及抗原性发生改变;2012年以后分离毒株均为变异株,并已成为上海市的主要流行毒株。本研究为PRV分子致病机制及分子流行病学研究提供了依据。

Molecular Variation Analysis on Virulence Genes Related to Pseudorabies Virus in Shanghai City

In order to identify the molecular characteristics and variation of major virulence genes(gB,gC,gD and gE)of pseudorabies virus(PRV),28 strains isolated from 2010 to 2015 were amplified and sequenced by PCR assay.The results showed that multi-site mutations appeared in the epitope zones of all the genes;compared to the gD gene isolated in 2010,six consecutive amino acid insertions appeared in the strains isolated since 2012.Based on the genetic evolution trees of gB,gC,gD and gE gene,the four strains isolated in 2010 belonged to the same big branch as the strains isolated since 2012,but they were closely related to the classical strains,which were in the same small branch;the strains isolated in 2012 were closely related to the domestic variant strains isolated since 2011,which belonged to another branch.The virulence and antigenicity of the genes might be changed by the mutations of amino acids in the epitope zones.All the strains isolated since 2012 were variant,and had become prevalent in Shanghai City.Therefore,some references were provided for the study of PRV molecular pathogenesis and molecular epidemiology.