鸡传染性支气管炎病毒纤突蛋白的目的基因点突变对其免疫原性的影响

反转录聚合酶链反应扩增鸡传染性支气管炎病毒中国流行株的主要免疫原纤突蛋白Ｓ１基因，将其插入载体ｐＵＣ１８的ＢａｍＨⅠ／ＨｉｎｄⅢ位点，在大肠杆菌中实现目的的基因的分子克隆。经克隆化Ｓ１基因的限制性酶切片多段多态性分析和Ｓｏｕｔｈｅｒｎ杂交之后，双脱氧链终止法测定其５‘端高变区核苷酸序列，并以此与ＧｅｎｅＢａｎｋ中的参考毒株Ｍａｓｓａｃｈｕｓｓｅｔｔｓ４１相应序列作比较，分析其同源性。

EFFECT OF SITE MUTATION IN SPIKE 1 PROTEIN GENE ON IMMUNOGENICITY OF THE AVIAN INFECTIOUS BRONCHITIS VIRUS

After cloning and identification of the gene encoding spike l protein of the avian infectious bronchitis virus(IBV) HD isolate of China, the sequence of the 5' end within the hypervariable region (HVR) of the S1 gene was analyzed, and compared with the corresponding sequence of the IBV standard M41 strain from the GeneBank. One bp site mutation on the analyzed sequence was found between M41 and the HD strains, which was located at the 350nt after ATG, i. e. the Gly in HD replaced for Ala in M41 at the 41 amino acid residue of S1 glycoprotein. Cross protection between two vaccine strains showed that significant different protective effect can be induced by the site mutation on 5' end within the HRV of the S1 gene on the immunogenicity of IBV.