Chang B H, Shimmin L C, Shyue S K, Hewett-Emmett D, Li W H
Center for Demographic and Population Genetics, University of Texas, Houston 77225.
Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):827-31. doi: 10.1073/pnas.91.2.827.
In humans and rodents the male-to-female ratio of mutation rate (alpha m) has been suggested to be extremely large, so that the process of nucleotide substitution is almost completely male-driven. However, our sequence data from the last intron of the X chromosome-linked (Zfx) and Y chromosome-linked (Zfy) zinc finger protein genes suggest that alpha m is only approximately 2 in rodents with a 95% confidence interval from 1 to 3. Moreover, from published data on oogenesis and spermatogenesis we estimate the male-to-female ratio of the number of germ cell divisions per generation to be approximately 2 in rodents, confirming our estimate of alpha m and suggesting that errors in DNA replication are the primary source of mutation. As the estimated alpha m for rodents is only one-third of our previous estimate of approximately 6 for higher primates, there appear to be generation-time effects--i.e., alpha m decreases with decreasing generation time.
在人类和啮齿动物中，突变率的雄性与雌性比例（αm）被认为极大，以至于核苷酸替换过程几乎完全由雄性驱动。然而，我们来自X染色体连锁（Zfx）和Y染色体连锁（Zfy）锌指蛋白基因最后一个内含子的序列数据表明，在啮齿动物中αm仅约为2，95%置信区间为1至3。此外，根据已发表的关于卵子发生和精子发生的数据，我们估计啮齿动物中每代生殖细胞分裂数的雄性与雌性比例约为2，这证实了我们对αm的估计，并表明DNA复制错误是突变的主要来源。由于啮齿动物的估计αm仅为我们先前对高等灵长类动物约6的估计的三分之一，似乎存在世代时间效应——即，αm随世代时间的缩短而降低。
