1株鸡传染性法氏囊病毒VP2基因的克隆及其分子流行病学分析

摘要

In order to understand the epidemiological characteristics of infectious bursal disease virus (IBDV) in Henan province,the molecular epidemiology of VP2 gene from IBDV (XX511 strain) isolated from a chicken farm in Xinxiang was studied.According to the IBDV genome sequences information published in GenBank,specific primers were designed and synthesized,and the VP2 hypervariable region of IBDV was cloned and analyzed by RT-PCR.The sequence alignment was done,and evolutionary tree was drawn for virulence-related two hydrophilic and heptapeptide regions in VP2 hypervariable region between XX511 strain and other reference strains at home and abroad.The results showed that the homology of amino acid sequence of hypervariable region of VP2 gene with that of virulent strains D49706 and AJ878898 was 96.8％,and 100％ with that of Guangdong strain JQ911703.Compared with the reference classical strain,the XX511 strain had a mutation of one amino acid in the first hydrophilic region.By comparing with other epidemic strains in China (including Henan),we found that strain XX511 was in the same branch with Guangdong epidemic strain JQ911703 in 2012.%为了解河南地区鸡传染性法氏囊病毒(IBDV)的流行特征,研究了分离于河南新乡地区某发病鸡场的1株IBDV(XX511毒株)VP2基因的分子流行病学特征.根据GenBank公布的IBDV基因组序列信息,设计合成特异性引物,应用RT-PCR方法对分离于新乡某发病鸡场的IBDV野毒株XX511的VP2高变区进行克隆及分析,并将XX511毒株的VP2高变区中与毒力相关的2个亲水区及七肽区与国内外其他参考毒株进行序列比对,绘制进化树.结果显示,XX511毒株与超强毒株D49706、AJ878898的VP2基因高变区氨基酸序列的同源性均为96.8％,与广东地区JQ911703毒株具有100％的同源性.与参照的经典毒株相比,XX511毒株在第一亲水区发生了1个氨基酸位点的突变.通过与国内外(包括河南地区)其他流行毒株的比对及进化分析发现,XX511毒株与2012年广东流行JQ911703毒株处于同一分支.