戊型肝炎基因重组研究

目的探讨戊型肝炎病毒基因重组及其对病毒抗原性的影响。方法收集HEV基因全序列,经过对齐、去除空位处理后,运用RDP2.0软件进行筛查,然后利用SimPlot3.5.1软件进行相似性分析和BOOTSCAN分析,对基因重组加以验证,并构建最大似然比进化树,观察重组片断拓扑结构的改变。结果利用RDP2.0软件共检测到3个重组序列,分别是AF459348、D11093、D11092,都是Ⅰ型HEV。相似性分析和BOOTSCAN分析都显示D11093、D11092重组是有统计学意义的,重组片断最大似然进化树的拓扑结构也发生了改变,都发生在Ⅰ型ORF1区。地缘分析表明D11092是基因重组的产物,而D11093极有可能是实验室内发生的重组。结论HEV进化过程中也存在重组,主要发生在Ⅰ型ORF1区;HEV基因重组对于未来HEV抗原性改变可能影响不大。

Genetic recombination in hepatitis E virus

Objective To explore recombination in Hepatitis E virus of different types and its influence on antigenicity.Methods Complete genomes of hepatitis E virus were collected from GenBank,and were aligned with MEGA3.1.All sites including gaps were removed from the alignment.Gene recombination was screened with RDP 2.0 software and was further validated by similarity analysis and BOOTSCAN analysis with SimPlot 3.5.1 software.Changes in topology of phylogenetic tree were detected with Maximum likelihood method(ML).Prediction of influence on antigenicity by gene recombination was obtained by observation of localization in which recombination occurred.Results Three putative recombinants including AF459348,D11093 and D11092 were detected with RDP 2.0.D11093 and D11092 were proved as occurrence of recombination by similarity analysis and BOOTSCAN analysis,and alternation in topological structure was found.Recombination occurred in ORF1 region.D11092 was a production of recombination in epidemic area,while recombination in D11093 might be a consequence of recombination within laboratory by analysis on isolation area of virus.Conclusions Genetic recombination occurs in HEV evolution,and mainly in ORF1 region of type I HEV.Its importance in changing HEV antigen is ignorable.