传染性法氏囊病病毒自然重配株全基因组序列分析  

Genomic sequence analyses of reassortment strains of infectious bursal disease virus in nature

作　　者：朱向东[1,2] 王永山[1] 欧阳伟[1] 潘群兴[1] 毕振威[1] 李月华[1,2] 范红结[2] 王笑梅[3] 

机构地区：[1]江苏省农业科学院兽医研究所农业部兽用生物制品工程技术重点实验室国家兽用生物制品工程技术研究中心,江苏南京210014 [2]南京农业大学动物医学院,江苏南京210095 [3]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室,黑龙江哈尔滨150001

出　　处：《中国兽医学报》2014年第2期219-226,共8页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金资助项目(31272537);江苏省自然科学基金资助项目(BK2010471;BK2012787)

摘　　要：从具有新的流行病学特征的传染性法氏囊病（IBD）发病鸡群中分离到2株传染性法氏囊病病毒（IBDV），分别命名为QL和ZZ—ll，对4周龄SPF鸡的致死率分别为94％和86％。为分析该毒株的分子生物学特征，对其全基因组序列进行了测定，2个病毒株基因组A节段长度为3260bp、B节段长度2827bp。病毒演化分析结果显示2个病毒基因组A节段的核苷酸序列与已发表的强毒株序列的同源性分别为96．8％～98．1％和96．9％～98．4％，处在IB—DV超强毒株分支上；而B节段与已发表的弱毒株序列的同源性分别为89．7％～90．4％和90．0％～90．7％，位于弱毒株分支上。IBDV超强毒株和弱毒株序列特征氨基酸残基与基序分析表明，QL和ZZ—11两个病毒株的A节段VP2基因的氨基酸残基为222A、249Q、253Q、254G、256I、294I和299S，七肽基序为SWSASGS，均符合超强毒株的分子特征；而B节段777～782位核苷酸序列为GGTGCC，没有KpnI酶切位点，具有弱毒株的序列特点。以上分析结果表明，QL和ZZ—11为IBDV自然重配株，A节段源于超强毒株，而B节段源于弱毒株。Two isolates of infectious bursal disease virus （IBDV） with new epidemiological charac teristics in China were acquired and named as QL and ZZ-11. The mortality rate of specific patho-gen free （SPF） chickens inoculated with the isolate QL was 94% ,and ZZ-11 was 86%. By sequen cing,the genomes of QL and ZZ-11 were the same in size,and segment A and B were 3 260 bp and 2 827 bp,respectively. The phylogenetic analysis showed that segment-A of the two isolates were 96.8%o to 98.1% and 96.9% to 98.4 % homology to that of the published strains belonging to the very virulent strain branch;while segment-B was in the branch of the attenuated strains,the ho- mologies were from 89.7% to 90.4% and from 90.0% to 90.7%. Segment A of the two isolates had molecular characteristics of very virulent strains with 222A, 249Q, 253Q, 254G, 256I, 294I, 299S and heptapeptide motif SWSASGS in VP2 gene; While segment B owned the sequencecharacteristics of attenuated strains which did not have Kpn I restriction sites at their 777-782 nu cleotides （GGTGCC）. It indicated that QL and ZZ-11 might be the natural reassortment viruses with segment A derived from the very virulent strains and segment B from the attenuated strains, separately. The discovery of reassortment viruses in nature suggests an additional risk of using live IBDV vaccines,which could act as genetic donors for genome reassortment.

关 键 词：传染性法氏囊病病毒(IBDV) 病毒演化 重配病毒 序列分析 

分 类 号：S852.65[农业科学—基础兽医学]