The hidden side of invasions: Massive introgression by local genes
The hidden side of invasions: Massive introgression by local genes
复制标题
DOI：
10.1111/j.1558-5646.2008.00413.x
复制
发表时间：
2008-08-01
期刊：
影响因子：
3.3
通讯作者：
Excoffier, Laurent
中科院分区：
文献类型：
--
作者：
Currat, Mathias;Ruedi, Manuel;Excoffier, Laurent
尽管有数以百计的报告涉及植物和动物，但渗透的潜在机制仍然不清楚，即使经常引用某种形式的选择。在最近在新栖息地定居的物种中一再报告了渐渗，这表明应该更多地关注人口统计过程，以了解渐渗的机制。在这里，我们通过空间显式模拟表明，如果入侵物种与当地物种之间的杂交没有得到严格防止，那么在入侵被占领的领土期间，中性基因的大量导入发生。我们还证明了渗入几乎完全发生在从本地到入侵物种，特别是对于远离入侵来源的种群，并且这与两个物种的相对密度无关。这种模式在基因流动减少的标记上表现得最强，这与细胞器基因通常优先跨物种边界导入的观察结果一致。对文献的调查表明，在动物和植物中，大多数已发表的关于范围扩大过程中的入侵性的经验研究，都遵循我们模型的预测。我们的结果表明，物种形成基因可以通过比较干扰的原生物种和入侵物种对的基因组来识别。
Despite hundreds of reports involving both plants and animals, the mechanisms underlying introgression remain obscure, even if some form of selection is frequently invoked. Introgression has repeatedly been reported in species that have recently colonized a new habitat, suggesting that demographic processes should be given more attention for understanding the mechanisms of introgression. Here we show by spatially explicit simulations that massive introgression of neutral genes takes place during the invasion of an occupied territory if interbreeding is not severely prevented between the invading and the local species. We also demonstrate that introgression occurs almost exclusively from the local to the invading species, especially for populations located far away from the source of the invasion, and this irrespective of the relative densities of the two species. This pattern is strongest at markers experiencing reduced gene flow, in keeping with the observation that organelle genes are often preferentially introgressed across species boundaries. A survey of the literature shows that a majority of published empirical studies of introgression during range expansions, in animals and in plants, follow the predictions of our model. Our results imply that speciation genes can be identified by comparing genomes of interfertile native and invading species pairs.