摘要
采用RT-PCR方法克隆测定传染性支气管炎病毒（Infections Bronchitis Virus，IBV）疫苗株H52全基因组序列，并与其它已知全基因组序列的我国分离株进行比较分析，以分析我国IBV地方分离株与疫苗株的分子遗传关系。结果表明，H52基因组全长为27630bp（不包括polyA），A＋T含量为61．8％，它与我国IBV分离株全基因组同源性在83．9％～95．2％之间，其中与KQ6的同源性最高（95．2％），与其余株均在88％以下。在基因组内基因的同源性中，以S1、S2与E变异最大，除KQ6外，其余各株（含台湾株）与H52在S1蛋白上的同源性只有72．4％～80．7％，在S2蛋白上的同源性为85．5％～88．1％，E蛋白为82．9％～93．3％。系统进化分析表明，国内分离株，除KQ6外，在进化分支中已独立于H52和其它Massachusetts型衍生毒株。H52与我国地方分离株存在较大的分子遗传差异，这些差异可能导致单纯Massachusetts型疫苗（如H120，H52）不能有效地免疫保护我国的鸡群。
To analyze the molecular genetic relationship between the infectious bronchitis virus(IBV) vaccine strain H52 and endemic IBV strains,the complete genome of this vaccine strain was sequenced by RT-PCR and compared with sequences of other Chinese IBV strains.The H52 strain was 27 627 nucleotides in length,with A+T content of 61.8%.The H52 strain showed homologies of 83.9%-95.2% of genomes with other IBV strains among which it had the highest homology with KQ6(95.2%) and lower homologies with the rest strains(88%).S1,S2 and E were revealed to be the more variable regions in the genomes.The similarities of S1,S2 and E between H52 and other Chinese strains were respective 72.4%-80.7%,85.5%-88.1%,and 82.9%-93.3% with except that KQ6 showed a closer relatedness with H52.In the phylogenetic analysis by full genomes and subregions,the Chinese IBV strains were independent from H52 and other Massachusetts strains on the evolution branch with except KQ6.These results have demonstrated that the H52 strain has a rather large molecular genetic divergence from most of the Chinese endemic strains,which may result in insuffiencient protection against the infection in the field.
出处
《中国动物传染病学报》
CAS
2009年第2期17-23,共7页
Chinese Journal of Animal Infectious Diseases
基金
国家科技支撑计划资助(2006BAD06A03)
国家自然科学基金项目(30625030)
