作　　者： ; ; ; ; ; ; ;

机构地区： 河南农业大学牧医工程学院

出　　处： 《西北农林科技大学学报（自然科学版）》 2009年第9期27-33,共7页

摘　　要： 【目的】研究鸡传染性支气管炎病毒（IBV）W侏膜蛋白基因的分子特征。【方法】根据GenBank中已发表的鸡传染性支气管炎病毒M基因序列，设计并合成1对特异性引物，利用RT-PCR技术成功扩增了IBV河南地方分离毒株W株M基因全长片段，然后进行克隆、测序，并与GenBank中发表的11株国内外参考毒株进行比较分析。【结果】获得的W株M基因全长为681bp，编码M蛋白226个氨基酸残基，其N端的前60nt为前导序列，近N端含有2个潜在的N-糖基化位点；3个跨膜区域分别位于21-37，45～68，74～94aa处，在171～176，183～193aa处有2个潜在的抗原位点，且M蛋白上有9个高度保守的半胱氨酸；与参考毒株相比，IBV-W株M基因的核苷酸同源性为88．2％～92．7％，推导的氨基酸同源性为91．1％～95．67％；M蛋白的突变主要发生在前16位氨基酸，其中第2位缺失1个氨基酸，第3～6位连续插入4个氨基酸，第8～9位缺失2个氨基酸，第14～16位的3个氨基酸发生连续突变，其他位点的氨基酸变异为点突变，M蛋白核苷酸序列的变异主要表现为静默突变，亲水区较疏水区更易变易；在系统发生进化树中，W株与BJ株处于同一个小的分支上，亲缘关系较近，而与其他参考株的亲缘关系较远。【结论】推测W株可能是一个新的变异株。 [Objection] The research was to study molecular characterization of matrix glyeoprotein gene of infectious bronchitis virus （IBV） W strain. [Method] The matrix glycoprotein gene of IBV-W strain isolated from Henan province was successfully amplified with a pair of specific primers by reverse transcription polymerase chain reaction （RT-PCR）. The PCR products were cloned, sequenced and compared with 11 reference IBV strains published in GenBank. [Result] The results showed that the full length sequence of M gene of W strain consisted of 681 nucleotides,coding 226 amino acid residues of M protein. A leading sequence （signal peptide,about 60 nucleotides） and two glycosylated sites were located nearby the N-terminal. Three transmembrane domains were located in the regions from 21 to 37,from 45 to 68,and from 74 to 94 amino acids respectively. Two potential antigen sites existed in the regions between 171--176 and between 183--193. M protein included nir,e highly conserved cysteine residues. The M gene sequence analysis showed that it shared 88.2 %--92.7% nucleotide homology and 91.1%--95.6% deduced amino acid sequence homology with IBV strains from GenBank. In M protein, there was a variable region which was mainly located in the sites from 1 to 16 amino acids,for example,one amino acid was lost at site 2,4 amino acids were inserted at site 3--6,2 amino acids were lost at the site 8--9,and 3 amino acids were mutated at site 14--16,but variations of amino acids at other sites were point mutations. The variations of nucleotide sequence in M protein were mainly manifested as silent mutation. Variations within the hydro-philicity region were easier than that in the hydrophobicity region. Phylogenetic analysis based on the nucleotide sequences of M gene revealed that IBV-W strain was situated in the same branch of the phylogenetic tree with BJ strain for more close relation,while it was far related to the other strains of IBV. [Conclusion] These results suggested that IBV-W isolated in this study was a new stra

关 键 词： 鸡传染性支气管炎病毒 基因 分子特征

领　　域： [农业科学] [农业科学] [农业科学] [生物学]