Barrio E, Latorre A, Moya A, Ayala F J
Department de Genètica, Facultat de Biologia, Universitat de València.
Mol Biol Evol. 1992 Jul;9(4):621-35. doi: 10.1093/oxfordjournals.molbev.a040749.
We have constructed restriction-site maps of the mtDNAs in 13 species and one subspecies of the Drosophila obscura group. The traditional division of this group into two subgroups (affinis and obscura) does not correspond to the phylogeny of the group, which shows two well-defined clusters (the Nearctic affinis and pseudoobscura subgroups) plus a very heterogeneous set of anciently diverged species (the Palearctic obscura subgroup). The mtDNA of Drosophila exhibits a tendency to evolve toward high A+T values. This leads to a "saturation" effect that (1) begets an apparent decrease in the rate of evolution as the time since the divergence of taxa increases and (2) reduces the value that mtDNA restriction analysis has for the phylogenetic reconstruction of Drosophila species that are not closely related.
我们构建了果蝇蒙昧族13个物种和1个亚种中线粒体DNA（mtDNA）的限制性酶切图谱。该族传统上分为两个亚族（亲缘亚族和蒙昧亚族），但这与该族的系统发育并不相符，其系统发育显示出两个界限分明的类群（新北区亲缘亚族和拟暗果蝇亚族），再加上一组非常混杂的古老分化物种（古北区蒙昧亚族）。果蝇的线粒体DNA有朝着高A+T值进化的趋势。这导致了一种“饱和”效应，即（1）随着分类单元分化时间的增加，进化速率明显下降；（2）降低了线粒体DNA限制性分析对于亲缘关系不紧密的果蝇物种系统发育重建的价值。
