Max Planck Institute for Plant Breeding Research, Cologne, Germany.
Mathematics and Bioscience, Department of Mathematics and Max F. Perutz Labs, University of Vienna, Vienna, Austria.
Nat Commun. 2022 Mar 18;13(1):1461. doi: 10.1038/s41467-022-28800-z.
Understanding how populations adapt to abrupt environmental change is necessary to predict responses to future challenges, but identifying specific adaptive variants, quantifying their responses to selection and reconstructing their detailed histories is challenging in natural populations. Here, we use Arabidopsis from the Cape Verde Islands as a model to investigate the mechanisms of adaptation after a sudden shift to a more arid climate. We find genome-wide evidence of adaptation after a multivariate change in selection pressures. In particular, time to flowering is reduced in parallel across islands, substantially increasing fitness. This change is mediated by convergent de novo loss of function of two core flowering time genes: FRI on one island and FLC on the other. Evolutionary reconstructions reveal a case where expansion of the new populations coincided with the emergence and proliferation of these variants, consistent with models of rapid adaptation and evolutionary rescue.
了解种群如何适应突然的环境变化对于预测未来挑战的反应是必要的，但在自然种群中，确定特定的适应性变体、量化它们对选择的反应并重建其详细历史是具有挑战性的。在这里，我们使用来自佛得角群岛的拟南芥作为模型，研究在突然转向更干旱的气候后适应的机制。我们发现，在选择压力的多变量变化之后，有全基因组适应的证据。特别是，在各个岛屿上，开花时间的缩短是平行的，大大提高了适应性。这种变化是由两个核心开花时间基因的从头丧失功能的趋同介导的：一个岛上的 FRI 和另一个岛上的 FLC。进化重建揭示了一个案例，即在这些变体出现和扩散的同时，新种群的扩张与之相吻合，这与快速适应和进化拯救的模型一致。
