Ishida N, Oyunsuren T, Mashima S, Mukoyama H, Saitou N
Laboratory of Molecular and Cellular Biology, Japan Racing Association, Tokyo.
J Mol Evol. 1995 Aug;41(2):180-8. doi: 10.1007/BF00170671.
The noncoding region between tRNAPro and the large conserved sequence block is the most variable region in the mammalian mitochondrial DNA D-loop region. This variable region (ca. 270 bp) of four species of Equus, including Mongolian and Japanese native domestic horses as well as Przewalskii's (or Mongolian) wild horse, were sequenced. These data were compared with our recently published Thoroughbred horse mitochondrial DNA sequences. The evolutionary rate of this region among the four species of Equus was estimated to be 2-4 x 10(-8) per site per year. Phylogenetic trees of Equus species demonstrate that Przewalskii's wild horse is within the genetic variation among the domestic horse. This suggests that the chromosome number change (probably increase) of the Przewalskii's wild horse occurred rather recently.
tRNAPro与大的保守序列块之间的非编码区是哺乳动物线粒体DNA D环区中变化最大的区域。对包括蒙古本土马、日本本土马以及普氏野马在内的四种马属动物的这个可变区（约270碱基对）进行了测序。这些数据与我们最近发表的纯血马线粒体DNA序列进行了比较。估计这四种马属动物中该区域的进化速率为每年每个位点2-4×10^(-8) 。马属动物的系统发育树表明，普氏野马处于家马的遗传变异范围内。这表明普氏野马的染色体数目变化（可能增加）是相当近期发生的。
