Orito E, Mizokami M, Ina Y, Moriyama E N, Kameshima N, Yamamoto M, Gojobori T
Second Department of Internal Medicine, Nagoya City University Medical School, Japan.
Proc Natl Acad Sci U S A. 1989 Sep;86(18):7059-62. doi: 10.1073/pnas.86.18.7059.
An analysis of molecular phylogeny was undertaken to examine whether the evolution of the hepadnavirus family is host-dependent. Using the nucleotide sequences of 18 strains, we constructed phylogenetic trees. The trees obtained show that all 12 strains of hepatitis B virus can be classified into four subgroups that are not compatible with conventional subtypes. We estimated the rate of synonymous (silent) substitution for hepatitis B virus to be 4.57 x 10(-5) per site per year. Applying this rate to the phylogenetic tree, we estimated that duck hepatitis B virus diverged from a common ancestor about 30,000 years ago at the earliest, that woodchuck hepatitis virus and ground squirrel hepatitis virus diverged about 10,000 years ago, and that hepatitis B virus diverged within the last 3000 years. Because these divergence times of the viruses are much more recent than those of the host species, it suggests that the hepadnavirus family evolved independently of host-species divergence.
进行了分子系统发育分析，以研究嗜肝DNA病毒科的进化是否依赖于宿主。利用18个毒株的核苷酸序列，我们构建了系统发育树。所得的树状图显示，所有12株乙型肝炎病毒可分为四个亚组，这与传统亚型不相符。我们估计乙型肝炎病毒的同义（沉默）替代率为每年每个位点4.57×10⁻⁵。将该速率应用于系统发育树，我们估计鸭乙型肝炎病毒最早在约30000年前从一个共同祖先分化出来，土拨鼠肝炎病毒和地松鼠肝炎病毒在约10000年前分化，而乙型肝炎病毒在过去3000年内分化。由于这些病毒的分化时间比宿主物种的分化时间近得多，这表明嗜肝DNA病毒科的进化独立于宿主物种的分化。
