Fossorial but widespread: the phylogeography of the common spadefoot toad (Pelobates fuscus), and the role of the Po Valley as a major source of genetic variability
Fossorial but widespread: the phylogeography of the common spadefoot toad (Pelobates fuscus), and the role of the Po Valley as a major source of genetic variability
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DOI：
10.1111/j.1365-294x.2007.03274.x
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发表时间：
2007-07-01
影响因子：
4.9
通讯作者：
Veith, Michael
中科院分区：
文献类型：
--
作者：
Crottini, Angelica;Andreone, Franco;Veith, Michael
棕背蜥（Pelobates fuscus）是一种穴居两栖动物，栖息于欧洲平原地区。为了揭示物种范围扩张和收缩事件的痕迹，我们对线粒体细胞色素B基因的702 bp进行了测序。为了推断种群历史，我们应用了嵌套分支地理分析（NCPA）等非线性地理方法，并使用概括统计分析了中性进化模型下的种群结构。人口被分配到不同的排水系统，我们测试了明确的避难所模型的假设，使用分子方差分析，核苷酸多样性，有效的人口规模估计，NCPA，错配分布和贝叶斯测年的信息。聚结模拟被用作推导或先验假设的地理学假设的可验证性的事后检验。我们的所有方法的组合，使重建的殖民历史和殖民地理的P. fuscus，并证实了先前的假设存在两个主要的遗传谱系内P. fuscus。使用非洲-欧洲vicariance的Pelobates cultripes和Pelobates varaldii和应用贝叶斯测年，我们估计分歧的这些不同的地理谱系上新世。我们建议存在三个不同的冰川避难所：（一）里海和黑海之间的地区作为“东部血统”的扩张的起源;（二）多瑙河系统作为“西部血统”的一部分多样性的中心;（三）波河流域，最大的遗传变异中心。这符合气候波动是青海云杉分化过程中的关键事件的假设。
Pelobates fuscus is a fossorial amphibian that inhabits much of the European plain areas. To unveil traces of expansion and contraction events of the species' range, we sequenced 702 bp of the mitochondrial cytochrome b gene. To infer the population history we applied phylogeographical methods, such as nested clade phylogeographical analysis (NCPA), and used summary statistics to analyse population structure under a neutral model of evolution. Populations were assigned to different drainage systems and we tested hypotheses of explicit refugial models using information from analysis of molecular variance, nucleotide diversity, effective population size estimation, NCPA, mismatch distribution and Bayesian dating. Coalescent simulations were used as post hoc tests for plausibility of derived or a priori assumed biogeographical hypotheses. Our combination of all approaches enabled the reconstruction of the colonization history and phylogeography of P. fuscus and confirmed a previous assumption of the existence of two major genetic lineages within P. fuscus. Using the Afro-European vicariance of Pelobates cultripes and Pelobates varaldii and applying Bayesian dating we estimated the divergence of these phylogeographical lineages to the Pliocene. We suggest the existence of three different glacial refugia: (i) the area between the Caspian and Black Seas as the origin for the expansion of the 'eastern lineage'; (ii) the Danube system as a centre of diversity for part of the 'western lineage'; (iii) the Po Valley, the largest centre of genetic variability. This fits the hypothesis that climatic fluctuation was a key event for differentiation processes in P. fuscus.