Xi J N, Graham D Y, Wang K N, Estes M K
Division of Molecular Virology, Baylor College of Medicine, Houston, TX 77030.
Science. 1990 Dec 14;250(4987):1580-3. doi: 10.1126/science.2177224.
Major epidemic outbreaks of acute gastroenteritis result from infections with Norwalk or Norwalk-like viruses. Virus purified from stool specimens of volunteers experimentally infected with Norwalk virus was used to construct recombinant complementary DNA (cDNA) and derive clones representing most of the viral genome. The specificity of the clones was shown by their hybridization with post- (but not pre-) infection stool samples from volunteers infected with Norwalk virus and with purified Norwalk virus. A correlation was observed between the appearance of hybridization signals in stool samples and clinical symptoms of acute gastroenteritis in volunteers. Hybridization assays between overlapping clones, restriction enzyme analyses, and partial nucleotide sequence information of the clones indicated that Norwalk virus contains a single-stranded RNA genome of positive sense, with a polyadenylated tail at the 3' end and a size of at least 7.5 kilobases. A consensus amino acid sequence motif typical of viral RNA-dependent RNA polymerases was identified in one of the Norwalk virus clones. The availability of Norwalk-specific cDNA and the new sequence information of the viral genome should permit the development of sensitive diagnostic assays and studies of the molecular biology of the virus.
急性肠胃炎的大规模流行爆发是由诺沃克病毒或诺沃克样病毒感染引起的。从实验感染诺沃克病毒的志愿者粪便样本中纯化的病毒被用于构建重组互补DNA（cDNA）并获得代表病毒基因组大部分的克隆。这些克隆的特异性通过它们与感染诺沃克病毒的志愿者感染后（而非感染前）的粪便样本以及纯化的诺沃克病毒的杂交得以显示。在粪便样本中杂交信号的出现与志愿者急性肠胃炎的临床症状之间观察到了相关性。重叠克隆之间的杂交分析、限制性酶切分析以及克隆的部分核苷酸序列信息表明，诺沃克病毒含有一个正义单链RNA基因组，在3'端有一个聚腺苷酸化尾巴，大小至少为7.5千碱基。在诺沃克病毒的一个克隆中鉴定出了病毒RNA依赖性RNA聚合酶典型的共有氨基酸序列基序。诺沃克特异性cDNA的可得性以及病毒基因组的新序列信息应有助于开发灵敏的诊断检测方法并开展该病毒的分子生物学研究。
