Analysis of Variation of Hepatitis C Viral Genome.

利用Chiron公司的专利资料，对C型肝炎病原日本丙型肝炎病毒（HCV- j）基因组进行了分析，其中含有部分HCV基因组结构。利用RT-PCR扩增和cDNA文库筛选获得的cDNA克隆，确定了HCV-J全基因组结构的核苷酸序列。HCV-J基因组全长9422个核苷酸，开放阅读框长9030个核苷酸。在氨基酸水平上，与黄病毒科的同源性较弱，但与其他动物病毒的核苷酸序列没有明显的同源性。因此，我们认为HCV-J应该被划分为一个不同于黄病毒和鼠疫病毒的新病毒科。HCV- j与原HCV分离株（HCV- us）的核苷酸序列差异24%，氨基酸序列差异15%，我们认为HCV- j与HCV- us是不同亚型的HCV。我们还利用RT-PCR分析了NS5区域的核苷酸序列，该区域编码RNA聚合酶。从日本不同地区的16份标本（肝炎和肝细胞癌患者血清）中获得19个HCV-J基因组，该地区与HCV-US的核苷酸序列差异为14-17%。此外，在HCV-J基因组中，2.5 ~ 11%的核苷酸序列和0 ~ 7%的氨基酸序列存在差异。这些结果显示了基因组的异质性和差异性。进口血制品的日本血友病患者中存在HCV-US型，且HCV-US型之间存在序列多样性（2-8%的核苷酸序列）。还分析了假定包膜区和RNA聚合酶结构域的序列多样性。该区域的氨基酸序列差异较大，毒株间存在12-31%的氨基酸序列差异。值得注意的是，我们发现了两个高变区，然而，我们将在未来阐明这些变区与病毒持续感染机制之间的关系。少

The genome of Japanese hepatitis C virus (HCV-J), causative agent of C-type hepatitis, has analyzed using the information of patent of Chiron Corp. containing a part of the genome structure of HCV. We have determined the nucleotide sequence of whole genomic structure of HCV-J from cDNA clones which were obtained by the amplification with RT-PCR and screening of cDNA library. HCV-J genome was 9422 nucleotides in length and had a long open reading frame of 9030 nucleotides. At the amino acid level we could find weak homology with those of the Flaviviridae, but not find any significant homology of the nucleotide sequence with other animal viruses. Therefore, we concluded that HCV-J should be classified into a new virus family distinct from the flaviviruses and pestiviruses. Comparison of HCV-J with the original isolate of HCV (HCV-US) showed 24% difference in nucleotide sequence and 15% difference in amino acid sequence and we proposed that HCV-J and HCV-US are different subtype HCV.We ha … More ve also analyzed the nucleotide sequence of putative NS5 region, which encodes RNA polymerase, by RT-PCR. 19 HCV-J genomes were obtained from 16 specimens (serum of patients with hepatitis and hepatocellular carcinoma) in various areas of Japan. 14-17% of nucleotide sequence in this region was different from that of HCV-US. Furthermore, 2.5-11% of nucleotide sequence and 0-7% of amino acid sequence differed among HCV-J genomes. These results showed the heterogeneity and variation of the genomes. HCV-US types were found in Japanese hemophiliacs received imported blood products and sequence diversity (2-8% of nucleotide sequence) was found among HCV-US types. Sequence diversity of putative envelope region was also analyzed as well as RNA polymerase domain. Variation of this region was more remarkable and 12-31% of amino acid sequence differed among virus strains. Notably, we found two hypervariable regions, however, we gave to clarify the relationship between these variable regions and the mechanism of persistent infection of virus, in future. Less