摘要
本研究应用RT-PCR方法扩增出分离自广西的26株鸡传染性支气管炎病毒(IBV)以及参考株M41和疫苗株H120、Ma5和4/91的3'端非编码区(3'UTR)的cDNA,并对其进行了克隆、序列测定、比较及其系统进化分析。序列分析结果表明,与Beaudette株的3'UTR序列相比较,26株分离的IBV中有1株和3株的分离株3'UTR序列分别插入了23个和2个碱基,另外有12株、6株、1株、2株和1株的分离株3'UTR序列分别缺失了1个、2个、22个、29个和84个碱基,不同毒株之间碱基数量最大相差达107个碱基。系统进化分析结果表明,26株分离株可分为4群,其中21株属于第Ⅰ群,与经典疫苗株H120的核苷酸同源性均较低(54.4%～75.5%);3株与4/91同属于第Ⅱ群;1株与H120同属于第Ⅲ群;另外1株单独属于Ⅴ群。综上所述,广西流行IBV的绝大部分毒株在3'UTR序列上与目前常用的疫苗株相比都发生了很大的变异,而且存在多种形式的碱基缺失和插入现象。由此,我们认为流行株的变异可能是疫苗不能提供有效保护的主要原因。
This investigation was the report on cloning,sequencing,comparing and phylogenetically analysis of the cDNA of 3＇ untranslated region（3＇UTR） sequence of 26 infectious bronchitis virus（IBV） strains isolated from Guangxi province of China the reference strain M41 and the vaccine strains H120,Ma5 and 4/91 which by using reverse transcriptase polymerase chain reaction（RT-PCR）.The results of sequence analysis showed that comparing with the Beaudette strain,there were 1 and 3 of Guangxi IBV strains which inserted 23 and 2 nucleotides（nts）,respectively.There were 12,6,1,2 and 1 Guangxi IBV strains which deleted 1,2,22,29 and 84 nts,respectively,and the maximal nucleotides difference was107 nts in 3＇ UTR sequence among Guangxi IBVs.The results of phylogenetic tree analysis showed that 26 Guangxi IBVs were classified into 4 distinct clusters.21 out of 26 IBV isolates were grouped into cluster Ⅰ and had lower homology with the classical vaccine strain H120（54.4%～75.5%）.3 isolates belonged to clusterⅡ,which included 4/91 strain.One isolate belonged to cluster Ⅲ,which included H120 strain.Another one isolate constituted cluster Ⅴ alone.In summary,most of IBV strains isolated from Guangxi had mutation in the 3＇UTR sequence comparing with the commonly used vaccine strains,and the nucleotide deletions and nucleotide insertions occurred in various ways among Guangxi IBV strains.Therefore,we believed that the genetic variations may be the main reason which vaccines can＇t protect effectively against epidemic strains in the field.
出处
《基因组学与应用生物学》
CAS
CSCD
北大核心
2010年第3期457-463,共7页
Genomics and Applied Biology
基金
国家自然科学基金(30700599)
广西自然科学基金(桂科青0728003和桂科自0991044)
广西科技攻关项目(0993009-2)
广西高等学校优秀人才资助项目(桂教人才0802)共同资助
