Allard M W, Honeycutt R L
Department of Organismic and Evolutionary Biology, Harvard University.
Mol Biol Evol. 1992 Jan;9(1):27-40. doi: 10.1093/oxfordjournals.molbev.a040706.
Mitochondrial DNA (mtDNA) sequence variation was examined in eight taxa of the African rodent family Bathyergidae, as well as in two taxa representative of the Old-World hystricognathid rodent families Petromyidae and Thryonomyidae. A total of 812 bp, constituting domains I-III of the 12S ribosomal rRNA gene, were compared for each taxon. The high levels of intrafamilial mtDNA sequence divergence observed (average 16.8, range 3.5-23.2) support an ancient origin for the five genera, 20-38 Mya. These data do not support the current subfamilial groupings of the Bathyergidae. The eastern African naked mole-rat, Heterocephalus glaber, is the most basal representative of the family, with the silvery mole-rat, Heliophobius, being the next most basal. South African forms [dune, common, and cape mole-rats (Bathyergus, Cryptomys, and Georychus, respectively)] group together. The independent origin of the common mole-rat, relative to the naked mole-rat, suggests that complex social systems evolved in parallel along different bathyergid lineages. The 12S rRNA gene is not evolving at a higher rate within the rodent lineages, relative to that seen for artiodactyls and primates. Bathyergid rodents appear to fall at an extreme end of the spectrum of mammalian variation, with respect to both transition/transversion ratios and divergence, showing much lower transition/transversion ratios than those previously reported for intrafamilial comparisons.
对非洲啮齿动物滨鼠科的八个分类单元以及旧大陆豪猪亚目啮齿动物科鳞尾松鼠科和蔗鼠科的两个代表性分类单元的线粒体DNA（mtDNA）序列变异进行了研究。每个分类单元比较了总共812个碱基对，它们构成了12S核糖体RNA基因的结构域I - III。观察到的科内mtDNA序列高度分歧（平均16.8，范围3.5 - 23.2）支持这五个属起源于2000万至3800万年前。这些数据不支持当前滨鼠科的亚科分组。东非裸鼹鼠（Heterocephalus glaber）是该科最基部的代表，银毛鼹鼠（Heliophobius）是其次基部的。南非的种类（分别为沙丘鼹鼠、普通鼹鼠和海角鼹鼠，即Bathyergus、Cryptomys和Georychus）聚在一起。普通鼹鼠相对于裸鼹鼠独立起源，这表明复杂的社会系统在不同的滨鼠科谱系中平行演化。相对于偶蹄目动物和灵长目动物，12S rRNA基因在啮齿动物谱系中的进化速度并不更快。就转换/颠换比率和分歧而言，滨鼠科啮齿动物似乎处于哺乳动物变异范围的极端，其转换/颠换比率远低于先前报道的科内比较结果。
