Gojobori T, Moriyama E N, Kimura M
National Institute of Genetics, Mishima, Japan.
Proc Natl Acad Sci U S A. 1990 Dec;87(24):10015-8. doi: 10.1073/pnas.87.24.10015.
Evolution of viral genes is characterized by enormously high speed compared with that of nuclear genes of eukaryotic organisms. In this paper, the evolutionary rates and patterns of base substitutions are examined for retroviral oncogenes, human immunodeficiency viruses (HIV), hepatitis B viruses (HBV), and influenza A viruses. Our results show that the evolutionary process of these viral genes can readily be explained by the neutral theory of molecular evolution. In particular, the neutral theory is supported by our observation that synonymous substitutions always much predominate over nonsynonymous substitutions, even though the substitution rate varies considerably among the viruses. Furthermore, the exact correspondence between the high rates of evolutionary base substitutions and the high rates of production of mutants in RNA viruses fits very nicely to the prediction of the theory. The linear relationship between substitution numbers and time was examined to evaluate the clock-like property of viral evolution. The clock appears to be quite accurate in the influenza A viruses in man.
与真核生物的核基因相比，病毒基因的进化速度极快。本文研究了逆转录病毒癌基因、人类免疫缺陷病毒（HIV）、乙型肝炎病毒（HBV）和甲型流感病毒的碱基替换进化速率和模式。我们的结果表明，这些病毒基因的进化过程很容易用分子进化的中性理论来解释。特别是，我们观察到同义替换总是比非同义替换占主导地位，这一观察结果支持了中性理论，尽管不同病毒之间的替换率差异很大。此外，RNA病毒中进化碱基替换的高发生率与突变体产生的高发生率之间的精确对应非常符合该理论的预测。研究了替换数与时间之间的线性关系，以评估病毒进化的时钟样特性。在人类的甲型流感病毒中，这种时钟似乎相当准确。
