鸡传染性支气管炎病毒中国分离株S1基因的序列分析

采用RTPCR方法扩增了12株鸡传染性支气管炎病毒中国分离株的全长S1基因,并进行了序列分析。通过与GenBank中登录的其他IBV参考毒株S1基因序列比较,进行了系统进化分析。结果表明,12株分离毒株属于同一个进化群的2个不同进化亚群。其中11株分离株与国内一些分离株亲缘关系最近,属于同一进化亚群,而广西分离株GX041则与欧洲毒株4/91亲缘关系较近,属于另一亚群。这些结果说明,中国各地的流行毒株变异较大,实际免疫中要根据流行毒株的特性选择合适的疫苗株来进行。

Sequence analysis of S1 gene of IBV strains isolated in China

S1 genes of 12 strains of infectious bronchitis virus(IBV) isolated in China were amplified using RT-PCR, and the cDNA sequences of those strains were determined. Nucleotide sequence analysis was processedby comparingwith the published S1 genesequencesof other avian IBV strains in GenBank. Using the software of MEGA to analyze molecular phylogeny, a phylogenetic tree was constructed with neighbor-joining method and maximum parsimony method. The phylogenetic tree based on the nuc- leotide sequences of the S1 gene revealed that 12 Chinese IBV isolates had evolved intoone monogroupbut could be divided into twodistinct subgroups. The results showed that S1 gene of 11 IBV isolates was most closely related to that of other IBV strains isolated in China, while GX04-1 showed acloser phylogenetic relationship with European strain 4/91. The results suggested that there were a high variability among IBV isolates co-circulating in China and vaccines should be developed based on the local strains of IBV.