戊型肝炎病毒基因ORF1、ORF2阳性选择分析

Positive selection of ORF1 and ORF2 in hepatitis E virus genome

摘要: 目的探讨戊型肝炎病毒基因2个主要读码框(ORF)1、(ORF)2是否存在阳性选择位点。方法p¨p^.收集戊型肝炎基因全序列,利用MEGA3.0软件进行序列比对,校对密码子。PHYLIP3.6构建NJ进化树,PAML4.0分析阳性选择位点。结果平均进化率估计提示ORF1、ORF2均以净化选择为主,平均ω分别为0.029,0.024;中性进化模型显示有ORF1有93%的位点属于保守位点。平均ω=0.018;ORF2有98%的位点属于保守位点,平均ω=0.018;阳性选择模型分析结果提示ORF1、ORF2没有阳性选择位点。结论HEV进化过程中可能不存在阳性选择的进化模式。

Abstract: ObjectiveTo explore positive selection sites in ORF1 and ORF2 of hepatitis Evirus(HEV)genome.MethodsThirty-one complete genomes of types of HEV were retrieved from GenBank,and were aligned,corrected by codon with MEGA 3.1 software package.Phylogenetic tress were constructed with PHYLIP3.6 package.Adaptive evolution was analyzed with PAML 4.0 package.ResultsIt was revealed that purified evolution prevailed the ORF1 and ORF2 with ω of 0.029 and 0.024 respectively.Ninety-three percent of ORF1 sites and 98 percent of ORF1 sites were conservative with ω of 0.018 by neutral evolution model.No positive selection site was found in ORF1 or ORF2.ConclusionNo positive selection site was found in ORF1 or ORF2,which indicated that positive selection was not prevailing during HEV evolution.