肾型鸡传染性支气管炎病毒J株S1基因克隆和序列分析

Cloning and sequence analysis of S1 gene of isolate J of avian nephropathogenic infectious bronchitis virus

采用特异引物对来自浙江地区的肾病型鸡传染性支气管炎病毒(IBV)J株进行RT PCR,将扩增得到的S1基因cDNA克隆入pBluescriptSK质粒载体中,经克隆、鉴定后测序。结果显示,IBV J株S1基因全长为 1 73 1nt,编码一条 576个氨基酸组成的多肽,其核苷酸与已报道的IBV M4 1、H12 0 、Beaudette、Beijing、D4 1、Gray、4/91毒株的同源性为 82.73 %～ 78.4 2 %,有大量的点突变并且伴有基因插入和基因缺失;经S1蛋白分子进化系统分析,提示J株与其它各毒株的亲缘关系较远,为一新的IBV变异株。

WT5”BZ]cDNA of S1 gene of isolate J of avian nephropathogenic infectious bronchitis virus(IBV) isolated from Zhejiang province was amplified by reverse transcription polymerase chain reaction with special primers and cloned into plasmid pBluescript SK. The recombinants were identified by digestion of restriction enzyme BamHI,HindⅢ and PCR amplification, while the recombinants were sequenced. The results show that cDNA of S1 gene of isolate J of IBV was composed of 1 731 nucleotides encoding a polypeptide of 576 amino acids. Nucleotide homogeneity of S1 gene of IBV J isolate with S1 genes of other IBV strains M 41 , H 120 , Beaudette, Beijing, D 41 , Gray, 4/91 ranged from 82.73% to 78.42%. S1 gene of IBV J isolate existed much point mutation, as well as gene insert and gene deletion. Evolution analysis indicated that IBV J isolate was far relation to the other strains of IBV. These results suggested that IBV J isolate was a new variant of IBV.