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目的 检测戊型肝炎病毒 (HEV)摩洛哥株非编码区 (UTR)序列 ,探讨HEV非编码区序列能否作为其基因型分型的依据。方法 使用基于RNA连接酶的cDNA末端快速扩增法 (RLM RACE)扩增HEV摩洛哥株 5′和 3′端片段并测序。所得序列使用LASERGENE和PHYLIP软件包与其他 2 9株HEV序列比较。结果 只有基于甲基化帽子结构的RLM RACE扩增出了 5′端片段。HEV摩洛哥株 5′端UTR有 2 6个核苷酸 ,3′端polyA之前有 6 5个核苷酸。基于 3′端UTR序列的进化树与基于全基因序列的进化树不全相同。HEV 3′端至少需要 10 0个左右核苷酸长的序列才可进行HEV基因型分型。结论 HEV摩洛哥株 5′端有甲基化帽子结构。HEV 3′端UTR序列不能完全代替全基因组序列进行基因型分型。部分序列替代全基因组进行基因型分型时需要考虑其部位和长度因素。
Objective To detect the sequence of non-coding region (UTR) of Hepatitis E virus (HEV) in Morocco and to investigate whether HEV noncoding region can be used as a basis for genotyping. Methods The 5 ’and 3’ end fragments of HEV Moroccan strain were amplified using RNA ligase based rapid amplification of cDNA ends (RLM RACE) and sequenced. The resulting sequences were compared to the other 29 HEV sequences using the LASERGENE and PHYLIP software packages. Results Only the 5 ’end of the RLM RACE based on the methylated cap structure was amplified. The HEV Moroccan strain has 26 nucleotides at the 5 ’UTR and 65 nucleotides at the 3’ polyA. Phylogenetic trees based on the 3 ’UTR sequence are identical to phylogenetic tree based on the whole gene sequence. HEV 3 ’end needs at least 10 0 nucleotides long sequence for HEV genotyping. Conclusion The 5 ’end of the HEV Moroccan strain has a methylated cap structure. HEV 3 ’UTR sequence can not completely replace the whole genome sequence genotyping. Partial sequence substitution of the whole genome for genotyping requires consideration of site and length factors.