两株不同毒力EV71全基因组序列测定及分析

Complete genome sequence analysis of two enterovirus 71 strains with different leveel of virulence

目的了解济南市2008年EV71的流行和变异情况,寻求潜在的EV71毒力决定位点。方法采用分段扩增的RT-PCR方法对EV71JN200803和JN200804株的基因组全长进行扩增、测序。对两株EV71的全基因组核苷酸、氨基酸序列进行比较,对非编码区进行RNA二级结构的预测和分析,并对VP1区和全基因组进行遗传进化分析。结果 EV71JN200803和JN200804株的基因组全长分别为7 405nt和7 404nt,编码区没有核苷酸的插入和缺失,全基因组序列的组成和结构均符合肠道病毒71型的特征。JN200803和JN200804全基因组有106个核苷酸突变,编码区98个,非编码区8个,编码区多数属于同义突变,仅造成16个氨基酸突变。遗传进化分析显示,EV71JN200803和JN200804株与2008年国内其他流行株同属C4亚型的C4a进化分支,与Fuyang/17.08/1株进化关系最近。结论 2008年济南市流行的EV71属于C4a亚型,济南分离株的毒力决定位点不但具有非单一性,而且具有较为独特的济南区域特点。

ABSTRACT.. In ordor to understand the prevalence and variation of Enterovirus 71 （EV71） in Jinan in 2008, and to seek the potential virulence gene site of EV71, The complete genome of JN200803 and JN200804 strains was amplified, sequenced and analyzed. The results showed that the full length of the EV71 JN200803 and JN200804 genome were 7 405 and 7 404 nt re- spectively, and no insertion or deletion was detected in the coding region. The complete genome sequences of JN200803 and JN200804 were compared. There were 106 nucleotide variations were founded, induding 98 nucleotide variations in the coding region, 8 nucleotide variations in the noncoding regions. The nucleotide variations happened in the coding region were synony- mous mutations except 16 amino acid mutations. The phylogenetic analysis based on VP1 region and complete genome indicated that JN200803 and JN200804 had the closesst genetic relationship with Fuyang/17.08/1, and belonged to the same subgeno- type C4a. The virulence gene site of EV71 strains isolated from Jinan possesses not only non-singularity but also the special dis- trict characteristics of Jinan.