中国人丙型肝炎病毒基因组的一级结构及其变异

PRIMARY STRUCTURE AND VARIATION OF CHINESE HEPATITIS C VIRUS GENOME

自河北省固安县和上海市的两份急性丙型肝炎病人血清分离丙型肝炎病毒RNA,纯化后经反转录和聚合酶链反应(PCR)获得覆盖病毒基因组全长的cDNA片段。通过对河北株丙型肝炎病毒基因全部cDNA序列的分析,以及对上海株丙型肝炎病毒部分重要区域cDNA序列的分析,确定了中国人丙型肝炎病毒基因cDNA的一级结构和变异趋势。实验结果表明,中国人丙型肝炎病毒的基因结构同日本与美国研究人员最初分离的丙型肝炎病毒基因结构相似。以中国河北株与日本HCV-J株比较,病毒基因有771个核苷酸不同,两者同源性为91.8％;氨基酸残基有174个不同,其同源性为94.3％。与美国HCV-1株相比,中国河北株有2011个棱苷酸发生变化,同源性为78.6％;氨基酸残基有458个发生变化,同源性为84.9％。河北与上海两株比较的结果发现,各区域变异程度大小不同,以E2基因区最高,NS3—NS4,NS5高度保守。总体水平上分析,我国的两株丙型肝炎病毒基因虽有变异,但总变异率很低,并且变异主要发生在结构基因区域。而与国外丙型肝炎病毒相比,变异则贯穿于全基因。表明中国丙型肝炎病毒基因组在核苷酸水平上有一定的共同特征。

Two acute hepathis C patient's sera collected seperatly from Hebei Province and Shanghai in China were used for isolation of China strain hepatitis C virus ( HCV ) genome RNA. Overlapping cDNA fragments ge-nerated by PCR were sequenced with the dideoxynucleotide method. Com-paring Hebei strain HCV with the original isolates of US HCV-1 and Japan HCV-J strain , 67.6% and 91.8% homology at the nucleotide Ievel was found respectively and at the amino acid Ievel, was 84.9% and 94.3%.The results also demonstrate the heterogenicity between HCV from Hebei ( Hebei strain) and Shanghai ( Shanghai strain ) in their core and E2 regions, but not in NS3-NS4(C-100)and NS5 regions where heterogenicity was found throughout the whole genome among HCV isolates from China, Japan and the United States.