SARS冠状病毒M基因变异规律分析  

Analysis on M genes variation rules of SARS-CoV

作　　者：胡族琼[1] 赵卫[1] 晏辉钧[2] 张文炳[1] 刘志伟[1] 郭新雄[1] 何凡[1] 江丽芳[2] 龙北国[1] 

机构地区：[1]南方医科大学公共卫生与热带医学学院,广州510515 [2]中山大学中山医学院微生物学教研室

出　　处：《中国公共卫生》2005年第12期1451-1452,共2页Chinese Journal of Public Health

基　　金：广东省科技攻关基金;广东省医药科研基金(A2004378)

摘　　要：目的测定SARS冠状病毒(SARS-CoV)GD322株M基因序列,与其他SARS-CoV M基因进行比较分析,初步了解SARS-CoV在流行过程中M基因的变异规律。方法提取GD322株RNA,经RT-PCR扩增M基因后克隆至T-载体,转化DH5α,并进行序列测定。以SARS冠状病毒多伦多株2(TOR2)M基因为基准,利用Clustal X软件与其他SARS-CoV M基因进行比较,了解变异情况,采用Protean软件预测α螺旋和B细胞抗原表位。结果完成GD322株基因测序(AY702026),通过对已发表81株SARS-CoV M基因序列初步分析,选定TOR2为基准株。发现36株M基因与TOR2株序列相同,5株存在同义突变,40株存在非同义突变。共有11个突变位点,其中9个非同义突变位点,2个同义突变位点。对非同义突变代表株Frankfurt1和TW5的M基因进行α螺旋和B细胞抗原表位预测,结果和基准株序列比,差异无统计学意义。结论SARS-CoV M基因虽然有随流行时间推移突变逐渐增大的趋势,但总突变率低,基因序列较稳定,且香港M旅馆相关毒株变异小于香港M旅馆无关毒株。变异对其抗原性无影响。Objective To discover the variations rules of M genes through sequencing the M gene of SARS-CoV GD322 isolate and to compare it with those of published on GenBank. Methods RNA was extracted from SARS-CoV GD322 strain and used for RT-PCR, then the PCR prducts were cloned into pGEM-T vector and transformed DH5a, with which was fol- Lowed M gene sequencing. This M gene sequence and other 81 M genes published on GenBank were used to compare with the M gene of TOR2 with Clustal X, from which the variation rules of M genes were gotten. Then, predicted the a turn and the possible B cell epitopes with Protean program and analyzed the variations effect on them. Results After sequencing the gene of GD322 isolate（AY702026） and analyzing those published 81 M genes, TOR2 was selected as the reference strain. Among the 82 M genes, 36 isolates＇ M genes were same as that of TOR2, 5 isolates synonymous mutation and 40 isolates nonsynonymous mutation. 11 nucleotide mutation sites were discovered in the 82 M genes, 9 of which were nonsynonymous mutation and 2 synonymous mutation. The results of predicting the a turn and the B cell epitopes of M genes of Frankfurt 1 and TW5 showed no differences to those of TOR2. Conclusion Though the variations of SARS-CoV M genes are of gradually increasing trend during the course of epidemic spread, the total mutation rate is quite small and the M gene sequences are considerably stable, the isolates related to M hotel varied less than those with no relation to. The variations of M genes have hardly affected the antigenicity of M protein.

关 键 词：SARS-COV M基因 序列分析 B细胞抗原表位 

分 类 号：R373.1[医药卫生—病原生物学]