Rapid microevolution during recent range expansion to harsh environments
Rapid microevolution during recent range expansion to harsh environments
复制标题
最近范围扩展到恶劣环境期间的快速微进化
DOI：
10.1186/s12862-018-1311-1
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发表时间：
2018-12-07
影响因子：
3.4
通讯作者：
Zhan, Aibin
中科院分区：
文献类型：
--
作者：
Chen, Yiyong;Shenkar, Noa;Zhan, Aibin
背景适应性进化是生物体在新环境中生存和繁衍的关键机制之一。最近的研究表明，物种中可能会迅速发生适应性进化，以应对范围扩张期间的新环境或环境挑战。然而，对于环境适应，许多研究成功检测到与当地环境相关的表型特征，但没有提供充分的微进化动力学遗传证据。因此，彻底研究快速微进化响应环境变化的遗传基础至关重要，特别是哪些基因和相关变异导致了环境挑战。在这里，我们对全基因组基因相关的微卫星进行了基因分型，以检测海洋被囊类入侵者海鞘（CionaRobista）在最近范围扩展到红海恶劣环境期间快速微进化的遗传特征。结果红海种群与全球其他种群显着不同。全基因组扫描以及多种分析方法成功鉴定了一组适应性基因。有趣的是，红海种群中几个适应位点的等位基因频率差异很大，我们发现这些适应位点的等位基因频率与当地环境因素之间存在显着相关性。此外，一组基因被注释为参与局部温度和盐度适应，并且所鉴定的适应性基因可能在很大程度上有助于对恶劣环境的成功入侵。结论本研究中获得的所有证据清楚地表明，环境驱动的选择在几代之内就在海鞘的基因组中留下了可检测的特征。这种快速的微进化过程在很大程度上导致了恶劣的环境适应，因此有助于在环境因素差异很大的不同水生生态系统中成功入侵。
BackgroundAdaptive evolution is one of the crucial mechanisms for organisms to survive and thrive in new environments. Recent studies suggest that adaptive evolution could rapidly occur in species to respond to novel environments or environmental challenges during range expansion. However, for environmental adaptation, many studies successfully detected phenotypic features associated with local environments, but did not provide ample genetic evidence on microevolutionary dynamics. It is therefore crucial to thoroughly investigate the genetic basis of rapid microevolution in response to environmental changes, in particular on what genes and associated variation are responsible for environmental challenges. Here, we genotyped genome-wide gene-associated microsatellites to detect genetic signatures of rapid microevolution of a marine tunicate invader, Ciona robusta, during recent range expansion to the harsh environment in the Red Sea.ResultsThe Red Sea population was significantly differentiated from the other global populations. The genome-wide scan, as well as multiple analytical methods, successfully identified a set of adaptive genes. Interestingly, the allele frequency largely varied at several adaptive loci in the Red Sea population, and we found significant correlations between allele frequency and local environmental factors at these adaptive loci. Furthermore, a set of genes were annotated to get involved in local temperature and salinity adaptation, and the identified adaptive genes may largely contribute to the invasion success to harsh environments.ConclusionsAll the evidence obtained in this study clearly showed that environment-driven selection had left detectable signatures in the genome of Ciona robusta within a few generations. Such a rapid microevolutionary process is largely responsible for the harsh environmental adaptation and therefore contributes to invasion success in different aquatic ecosystems with largely varied environmental factors.