2008年辽宁省乙脑病毒分离株全基因组特征分析

Molecular characterization of full-length genome of Japanese encephalitis virus isolated in Liaoning Province in 2008

目的对2008年分离自辽宁蚊虫的乙脑病毒株进行全基因组序列测定和分析，了解其全基因组特征。方法使用针对乙脑病毒全基因组测序引物，RT-PCR扩增片段，完成对病毒全基因组序列的测定。应用ClustalX（1．83）、ATGC（V4）、DNAStar、GENEDOC（3．2）、Mega（4．0）等生物学软件完成全基因组核苷酸和氨基酸序列分析及病毒的系统进化分析。结果乙脑病毒LN0828株基因组全长10965个核苷酸，其中从97位到10392位为开放读码框，编码3432个氨基酸。与GenBank中的32株乙脑病毒在全基因组水平的核苷酸总体差异率为1．6％～16．4％，氨基酸总体差异率为0．3％～5．1％。与减毒活疫苗株SA14—14．2相比，编码区共存在1186个核苷酸差异，86个氨基酸差异。全基因组序列系统进化分析显示LN0828株属于基因Ⅰ型乙脑病毒。结论与该地区2002年和2007年乙脑病毒分离株高度同源，关键位点氨基酸未见变异。

Objective To sequence and analyze the whole genome of Japanese encephalitis virus （JEV） isolated from mosquitoes in Liaoning province in 2008. Methods Using RT-PCR to amplify fragments with genome sequencing primer. The full-length genome was obtained by sequencing and splicing. The differentiation analysis for nucleotides, deduced amino acid sequence and phylogenetic tree was performed by the software of Clustal X （1.83）, ATGC（V4）, DNAStar, GENEDOC（3.2） and Mega（4.0）. Results The whole genome of strain LN0828 possesses 10 965 nucleotides. An open reading frame from 97 to 10 392 including 10 296 nucleotides is capable of coding for a 3432 amino acid oolyprotein. Comparison of strain LN0828 genomic sequence with those of 32 JEV isolates in GenBank showed that nucleotide sequence divergence ranges from 1.6% to 16.4%, which resulted in amino acid sequence divergence from 0.3% to 5.1%. In comparison with live attenuated vaccine stain SA14-14-2 in open reading frame, strain LN0828 has a total of t186 nucleotide substitutions, 86 amino acid divergences. Based on phylogenetic analysis, the strain LN0828 belongs to the genotype Ⅰ JEV. Conclusion The whole genome of strain LN0828 is close to those of isolates from Liaoning in 2002 and 2007, which were grouped into genotype Ⅰ JEV.