Latorre A, Barrio E, Moya A, Ayala F J
Department of Ecology and Evolutionary Biology, University of California, Irvine 92717.
Mol Biol Evol. 1988 Nov;5(6):717-28. doi: 10.1093/oxfordjournals.molbev.a040526.
We report a restriction-site study of the mitochondrial DNA (mtDNA) of seven species of the Drosophila obscura group. One species (D. azteca) belongs to the affinis subgroup; the other six species are classified in the obscura subgroup, three of them being from the old-world species (D. obscura, D. ambigua, and D. subobscura) and three from the new-world species (D. pseudoobscura, D. persimilis, and D. miranda). The mtDNA patterns suggest that the phylogeny of the group needs to be revised. The Nearctic obscura species appear as more closely related to D. azteca (affinis subgroup) than to the Palearctic species. The three Palearctic species are, in turn, a very heterogeneous group, with D. obscura no more closely related to D. subobscura and D. ambigua than to D. affinis or the Nearctic obscura species. The rates of mtDNA evolution are variable: some lineages have evolved at rates two or three times greater than others. If an average rate of 0.5% nucleotide substitutions/Myr is assumed, the divergence among the four main lineages in the phylogeny would have occurred 12-15 Myr ago, during the Miocene, which is consistent with biogeographic information.
我们报告了对果蝇隐种组七种果蝇线粒体DNA（mtDNA）的限制性酶切位点研究。其中一个物种（阿兹特克果蝇）属于近缘亚组；其他六个物种被归类于隐种亚组，其中三个来自旧世界物种（黑腹果蝇、模糊果蝇和次模糊果蝇），另外三个来自新世界物种（拟暗果蝇、拟似果蝇和米兰达果蝇）。mtDNA模式表明该组的系统发育需要修订。新北区的隐种与阿兹特克果蝇（近缘亚组）的关系似乎比与古北区物种的关系更密切。反过来，这三个古北区物种是一个非常异质的群体，黑腹果蝇与次模糊果蝇和模糊果蝇的关系并不比与近缘果蝇或新北区隐种更密切。mtDNA的进化速率是可变的：一些谱系的进化速率比其他谱系快两到三倍。如果假设核苷酸替换的平均速率为0.5%/百万年，那么系统发育中四个主要谱系之间的分歧将发生在1200 - 1500万年前的中新世，这与生物地理学信息一致。
