SARS冠状病毒CT基因型发现及相关特征

Find of SARS Coronavirus CT Genotype and Its Characterization

目的 研究SARS冠状病毒基因型及相关特征。方法 对杭州市首例SARS病人分离的SARS冠状病毒ZJ0 1株进行全基因组测序 ,并在GenBank数据库登录。记录号 :AY2 970 2 8,版本号 :gi:3 0 910 85 9。整个全基因组由 2 9715bp组成。使用GenBank数据库中最新登陆的SARS病毒的基因组进行序列比对、突变点分析和多态性分析、特殊片段的系统进化分析。结果 发现在ZJ0 1株的 93 91、 175 5 5、2 1712、 2 2 2 13和 2 7819位点 ,分别是T、T、G、T和T核苷酸碱基 ,和GenBank数据库中的其他SARS冠状病毒株比较 ,除第 1、 2、 4和 5突变位点 (C :G :C :C/T :T :T :T)之外 ,发现在 2 1712位点 (第 3个 )A/G突变也参于这一遗传标识。因此我们提出 5个突位点将 17株病毒分为两种基因型的新概念 ,即C :G :A :C :C与T :T :G :T :T两型 ,简称C型和T型。ZJ0 1病毒株属于T基因型 ,在中国大陆内地是首次发现和发表。突起蛋白基因片断的进化树分析 ,广州的GZ0 1C基因型株进化距离和其他病毒株相差甚远 ;比较而言 ,和C基因型BJ0 1、CUHK W1病毒株较为接近 ,其次是T基因型的F1和F2组。 5个突变位点 (C :G :A :C :C/T :T :G :T :T)的两个发生在编码突起蛋白 (S)的基因中 ,分别是A/G和C/T突变 ,由此引起的突起蛋白 (S)氨基酸变化是Asp/

Objective To study on SARS coronavirus genotyupe and its characterization.Methods A SARS coronavirus named ZJ01 were isolated from the throat swab samples taken from a patient in Hangzhou,Zhejiang province.The complete genome sequence of ZJ01 consists of 29715 bp(GenBank accession:AY297028,version:gi:30910859).We compared 127 SARS genome sequences in GenBank to analyze the common sequence variations,the probability of co occurrence of multiple polymorphisms or mutations,Phylogenetic analysis.Results By bioinformatics processing and analysis,It was found that the nucleotides at genome loci of 9391?17555?21712?22213 and 27819 were T,T,G,T and T,respectively.Compared with other SARS coronavirus genomes in the GenBank database,we detedted a A/G mutation at position 21712 besides the other 4 mutation loci(C:G:C:C/T:T:T:T)involved in this genetic signature.Therefore a novel definition was put forward that according to these 5 mutation loci,17 SARS coronavirus strains would be grouped into two genotypes,C:G:A:C:C/T:T:G:T:T and abbreviated as SARS coronavirus C genotype and T genotype.According to this novel definition,the ZJ01 isolate belongs to SARS coronavirus T genotype first discovered and reported in mainland,China.Phylogenetic analysis of spike protein gene fragment showed that,GZ01 isolate is phylogenetically distinct from other isolates.Compared to groups F1 and F2 of T genotype,isolates of BJ01 and CUHK W1 were more closely related to GZ01 isolate.It is interesting to find that two(A/G and C/T)of the five mutation loci(C:G:A:C:C/T:T:G:T:T)occurred in the spike protein gene,which cause changes of the Asp to Gly and Thr to Ile in the protein,respectively.Conclusions Attentions should be paid to whether these genotype and mutation patterns were related to virus's biological activities,epidemic characteristics and host clinical symptoms.