Tegelström H, Wyöni P I, Gelter H, Jaarola M
Department of Genetics, Uppsala University, Sweden.
Biochem Genet. 1988 Apr;26(3-4):223-37. doi: 10.1007/BF00561462.
The bank vole (Clethrionomys glareolus) and the northern red-backed vole (C. rutilus) are two closely related species where interspecific crosses result in fertile female but sterile male offspring. Mitochondrial DNA (mtDNA) from C. rutilus has passed the species barrier and is found in C. glareolus from northern Fennoscandia. The present report shows that the genetic distance between the two species, calculated from enzyme data (Nei's D), is 0.64. Isoelectric focusing of muscle proteins resolved around 55 bands, of which each species had 6 or 7 bands not present in the other species. Sequence divergence of mtDNA from the two species is 13.9%. A comparison between protein and mtDNA distances in other species pairs reveals a high correlation between the two measures, indicating that differences in mtDNA between taxa are not random when compared to divergence in protein-coding nuclear genes. The relationship between genetic divergence in proteins and that in mtDNA between Clethrionomys glareolus and C. rutilus is similar to that found in other species pairs. It is also shown that despite large differences on the protein level it is still, in some cases, possible for species pairs to produce fertile hybrid females.
小林姬鼠（Clethrionomys glareolus）和北美红背田鼠（C. rutilus）是两个亲缘关系密切的物种，它们的种间杂交会产生可育的雌性后代，但雄性后代不育。北美红背田鼠的线粒体DNA（mtDNA）跨越了物种屏障，在斯堪的纳维亚半岛北部的小林姬鼠中也有发现。本报告显示，根据酶数据（内氏遗传距离D）计算得出，这两个物种之间的遗传距离为0.64。肌肉蛋白的等电聚焦分离出约55条带，其中每个物种都有6或7条带是另一个物种所没有的。这两个物种的mtDNA序列差异为13.9%。对其他物种对的蛋白质和mtDNA距离进行比较后发现，这两种测量方法之间存在高度相关性，这表明与蛋白质编码核基因的差异相比，不同分类群之间mtDNA的差异并非随机。小林姬鼠和北美红背田鼠之间蛋白质和mtDNA的遗传差异关系与在其他物种对中发现的关系相似。研究还表明，尽管在蛋白质水平上存在很大差异，但在某些情况下，物种对仍有可能产生可育的杂交雌性后代。
