Braaker Sonja, Heckel Gerald
Computational and Molecular Population Genetics (CMPG), Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland.
Mol Ecol. 2009 Jun;18(11):2518-31. doi: 10.1111/j.1365-294X.2009.04189.x. Epub 2009 Apr 23.
The colonisation history and genetic structure of the common vole (Microtus arvalis) was investigated in the region of the Alps by analysing the mitochondrial cytochrome b gene (mtDNA) and 19 microsatellite loci (nucDNA) for 137 voles from 52 localities. mtDNA data provided a much refined distribution of three highly divergent evolutionary lineages in the region compared to previous studies. Although high mountain ranges are widely accepted to be barriers for colonisation processes for many organisms and especially small terrestrial mammals, our phylogeographic analyses showed clear evidence of four transalpine colonisation events by the common vole. Individual-based phylogenetic analyses of nucDNA and two alternative Bayesian-clustering approaches revealed a deep genetic structure analogous to mtDNA. Incongruence between nucDNA and mtDNA at the individual level was restricted to the regions of contact between the lineages. mtDNA patterns and strong female philopatry in M. arvalis suggest that the crossings of the Alps occurred during the colonisation of the region when it was free from ice after the last glaciation. nucDNA patterns suggest that some of the transalpine elements of this phylogeographic pattern were subsequently eroded by male-biased gene flow. We conclude that the combination of phylogeography and landscape genetics at the individual level can provide very detailed insights into colonisation events and may even allow differentiation between historical and more recent processes.
通过分析来自52个地点的137只田鼠的线粒体细胞色素b基因（mtDNA）和19个微卫星位点（核DNA），对阿尔卑斯山地区普通田鼠（Microtus arvalis）的殖民历史和遗传结构进行了研究。与之前的研究相比，mtDNA数据提供了该地区三个高度分化的进化谱系更为精细的分布情况。尽管高山山脉被广泛认为是许多生物尤其是小型陆地哺乳动物殖民过程的障碍，但我们的系统地理学分析显示，普通田鼠有四次穿越阿尔卑斯山的殖民事件的明确证据。基于个体的核DNA系统发育分析和两种替代的贝叶斯聚类方法揭示了与mtDNA类似的深层遗传结构。个体水平上核DNA和mtDNA之间的不一致仅限于谱系之间的接触区域。mtDNA模式和普通田鼠强烈的雌性留居性表明，阿尔卑斯山的穿越发生在该地区最后一次冰期后无冰的殖民化过程中。核DNA模式表明，这种系统地理模式中的一些跨阿尔卑斯元素随后被雄性偏向的基因流侵蚀。我们得出结论，个体水平上的系统地理学和景观遗传学相结合，可以为殖民事件提供非常详细的见解，甚至可能区分历史过程和更近的过程。
