Higuchi R G, Wrischnik L A, Oakes E, George M, Tong B, Wilson A C
Department of Biochemistry, University of California, Berkeley 94720.
J Mol Evol. 1987;25(4):283-7. doi: 10.1007/BF02603111.
Sequences are reported for portions of two mitochondrial genes from a domestic horse and a plains zebra and compared to those published for a quagga and a mountain zebra. The extinct quagga and plains zebra sequences are identical at all silent sites, whereas the horse sequence differs from both of them by 11 silent substitutions. Postmortem changes in quagga DNA may account for the two coding substitutions between the quagga and plains zebra sequences. The hypothesis that the closest relative of the quagga is the domestic horse receives no support from these data. From the extent of sequence divergence between horse and zebra mitochondrial DNAs (mtDNAs), as well as from information about the fossil record, we estimate that the mean rate of mtDNA divergence in Equus is similar to that in other mammals, i.e., roughly 2% per million years.
报告了家马和平原斑马两个线粒体基因部分的序列，并与已发表的斑驴和山斑马的序列进行了比较。已灭绝的斑驴和平原斑马序列在所有沉默位点上都是相同的，而马的序列与它们两者相比有11个沉默替换。斑驴DNA的死后变化可能解释了斑驴和平原斑马序列之间的两个编码替换。斑驴的近亲是家马这一假设没有得到这些数据的支持。根据马和斑马线粒体DNA（mtDNA）之间的序列分歧程度，以及化石记录的信息，我们估计马属动物mtDNA的平均分歧率与其他哺乳动物相似，即大约每百万年2%。
