Laboratory of Genetics, Comparative and Evolutionary Biology, University of Thessaly, Viopolis, Mezourlo, Larissa, Greece.
Department of Forestry and Natural Environment Administration, TEI of Thessaly, Larissa, Greece.
BMC Evol Biol. 2019 Jan 10;19(1):17. doi: 10.1186/s12862-019-1354-y.
The aim of the study was to use hybrid populations as well as island populations of the European brown hare (Lepus europaeus) to explore the effect of evolutionary events, such as the post-deglaciation translocations, spontaneous and human-mediated, local adaptation and the genetic drift in the shaping of the phylogeographic patterns of the species. For this purpose, we used molecular markers, both nuclear and mitochondrial, that are indicative for local adaptation as well as neutral markers to elucidate the patterns of population differentiation based on geographic isolation and the clade of origin. To broaden our analysis, we included data from our previous studies concerning mainland populations, to explore the genetic differentiation in the base of the geographic origin (mainland/island) of the populations.
Our results suggest that local adaptation shapes the differentiation in both genomes, favoring specific alleles in nuclear genes (e.g. DQA) or haplotypes in mtDNA (e.g. Control Region, CR). mtDNA variation was found to be in a higher level and was able to give a phylogeographic signal for the populations. Furthermore, the degree of variation was influenced not only by the geographic origin, but also by the clade of origin, since specific island populations of Anatolian origin showed a greater degree of variation compared to specific mainland populations of the European clade. Concerning the hybrid population, we confirmed the existence of both clades in the territory and we provided a possible explanation for the lack of introgression between the clades.
Our results indicate that the Quaternary's climatic oscillations played a major role in the shaping of the phylogeographic patterns of the species, by isolating populations in the distinct refugia, where they adapted and differentiate in allopatry, leading to genome incompatibilities observed nowadays.
本研究旨在利用欧洲野兔（Lepus europaeus）的混合种群和岛屿种群，探讨进化事件（如冰川消融后的迁徙、自然和人为介导的局部适应以及遗传漂变）对物种形成的系统地理格局的影响。为此，我们使用了分子标记，包括核和线粒体标记，这些标记既可以指示局部适应，也可以指示中性标记，以根据地理隔离和起源分支阐明种群分化的模式。为了扩大我们的分析，我们纳入了之前关于大陆种群的研究数据，以探讨种群起源地（大陆/岛屿）的遗传分化。
我们的研究结果表明，局部适应塑造了两个基因组的分化，有利于核基因（如 DQA）中的特定等位基因或线粒体 DNA（如控制区，CR）中的特定单倍型。线粒体 DNA 的变异程度较高，并且能够为种群提供系统地理信号。此外，变异程度不仅受地理起源的影响，还受起源分支的影响，因为来自安纳托利亚起源的特定岛屿种群与来自欧洲分支的特定大陆种群相比，显示出更大的变异程度。关于杂种种群，我们在该地区证实了两个分支的存在，并为分支之间缺乏基因渗入提供了一种可能的解释。
我们的研究结果表明，第四纪的气候波动在物种形成的系统地理格局中发挥了重要作用，通过将种群隔离在不同的避难所中，使它们在异地适应和分化，导致了现今观察到的基因组不相容性。
