鸡传染性支气管炎病毒中国地方分离株S1基因5′端的变异

Variation of 5′ end Region of S1 Gene of Avian Infectious Bronchitis Virus Isolates in China

对自海南省、广西省发生鸡传染性支气管炎 (IB)鸡群分离的 4株 IBV分离株 (Ha N- 1/95、Ha N- 2 /95、GX- 1/98、GX- 2 /98)的主要免疫原纤突蛋白 S1基因经 RT- PCR扩增其 5′端约 1.2 kb的目的片段 ,将其插入载体 p MD 18- T中 ,在大肠杆菌中实现目的基因的克隆。对克隆的目的基因经限制性酶切分析及 PCR鉴定后 ,以双脱氧链终止法测定其核苷酸序列 ,并与 Gen Bank中的参考毒株 (H12 0、SD- 1/97和 Holte)相应序列作比较 ,分析其同源性。结果表明 ,Ha N- 1/95、Ha N- 2 /95、GX- 1/98及 SD- 1/97与疫苗株 H12 0的核苷酸序列同源性分别为 99.5 %、99.2 %、97.9%和99.5 % ,其推导氨基酸序列同源性分别为 99.1%、98.9%、96 .9%和 99.2 %。 GX- 2 /98与 Holte株的核苷酸序列同源率为 99.0 % ,其推导的氨基酸序列同源性为 98.6 % ,而与其他中国分离株的核苷酸序列的同源性仅为 70 %左右 ,氨基酸序列的同源性仅为 6 8%左右。

It had been sequenced that 4 parts of the spike protein(S) gene which encode the aminoterminal of the S1 subunit of 4 isolates((HaN 1/95,HaN 2/95,GX 1/98,GX 2/98) of infectious bronchitis virus(IBV) respectively.The isolates were isolated in Hainan province in 1995 and Guangxi province in 1998 respectively.The four parts of S1 gene were amplified by reverse transcription polymerase chain reaction(RT PCR) using specific oligonucleotide primers and cloned into pMD 18 T vector.The nucleotide sequences of part of S1 gene of the four IBV isolates were determined and compared with published sequences of Holte,H120,SD 1/97 reference strains.The nucleotide sequence similarities of H120 with (HaN 1/95,HaN 2/95,GX 1/98) and SD 1/97 strains were 99 5%,99 2%,97 9%,99 5%,respectively.The similarities of the deduced amino acid sequences for the parts of S1 glycoprotein were 99 15%,98 9%,96 9%,99 2%,respectively.The nucleotide sequence similarity of GX 2/98 strain with Holte was 99 0%,and the similarity of the deduced amino acid sequence of GX 2/98 strain with Holte was 98 6%.