我国部分地区丙型肝炎病毒5′端部分基因序列的比较

SEQUENCE COMPARISON OF THE 5′NCR OF HCV GENOME IN DIFFERENT GEOGRAPHICAL REGIONS OF CHINA

目的 :测定我国部分地区丙型肝炎病毒 (HCV)分离株的 5′端部分cDNA序列 ,研究其基因型以及变异特点 ,为丙型肝炎的治疗和预后判断提供参考依据。方法 :用反转录套式聚合酶链反应 (RT -nPCR)法和 5′NCR区引物对我国部分地区 9株HCVRNA阳性血清进行扩增 ,扩增产物为 2 56bp ,将其纯化连接到PGEM -T载体上 ,然后进行测序 ,并与已发表的 50株HCV全序列的相应序列比较 ,并用种系发生法分析。结果 :该 9株HCV5′NCR核苷酸序列的同源性为93.0 %～ 99.6% ,其中 7株之间的同源性为 98.8%～ 99.6% ,另两株为 99.6%。同其它 50株同源性比较结果提示 ,7株属 1b型 ,2株属 2a型 ,种系发生法分析也支持这一结果。变异分析结果表明 ,同一亚型的核苷酸变异特点相似。结论 :该 9株HCV分离株分属 1b型和 2a型 ,该区同源性较高 ,但同一亚型的核苷酸变异特点相似。

Objective:To determine the sequence of partial cDNA of the 5′noncoding region of hepatitis C virus(HCV 5′NCR) genome in different geographical regions of China and to study the genotype and variation characteristic,so as to provide reference basis for treatment and prognosis of hepatitis C.Methods:A total of 9 HCV isolates from different regions of China were obtained. The HCV5′NCR of the isolates were amplified with reverse transcription-polymerase chain reaction(RT-PCR), the fragment of 256 bp was cloned into PGEM-T vector, then sequenced by auto-sequencing instrument. The sequences were compared with other 50 isolates previously reported and also analyzed by phylogenesis.Results:The homology of the 9 isolates was 93.0%～99.6%. Among them, 7 isolates had higher homology(98.8%～99.6%),the homology of the other 2 isolates was 99.6%. The results of the homology comparison among these 9 isolates and other 50 isolates reported in genbank suggested that isolates belongod to 1 b and 2 a genotype. Phylogenetic analysis also supported these results. The study of the nucleotide variation showed that the characteristic of the variation was similar in the same subtype.Conclusion:These 9 isolates belonged to 1 b and 2 a genotype. The homology was high in this region and the same subtype had the similar variation characteristics.