Single nucleotide mapping of trait space reveals Pareto fronts that constrain adaptation
Single nucleotide mapping of trait space reveals Pareto fronts that constrain adaptation
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DOI：
10.1038/s41559-019-0993-0
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发表时间：
2019-11-01
影响因子：
16.8
通讯作者：
Sherlock, Gavin
中科院分区：
文献类型：
--
作者：
Li, Yuping;Petrov, Dmitri A.;Sherlock, Gavin
权衡约束多个性状的性能同时提高。这种权衡定义了帕累托前沿，它代表了一组最佳个体，这些个体在任何一个特质上都不能得到改善，而另一个特质的表现则会降低。令人惊讶的是，实验进化往往产生的基因型在所有测量性状的性能改善，也许表明至少在短期内没有权衡。在这里，我们在酿酒酵母中密集采样适应性突变，以询问第一步适应性突变是否会导致生长周期中的权衡。我们分离了数千个在精心选择的条件下进化的适应性克隆，并量化了它们在生长周期每个部分的表现。我们也发现，一些第一步适应性突变可以在一定程度上改善所有性状。然而，我们的密集采样使我们能够确定权衡，并建立帕累托前沿之间的发酵和呼吸，呼吸和固定阶段。此外，我们确定，在祖先基因组中没有一个单一的突变可以绕过检测到的权衡。最后，我们对数百个适应性克隆进行了测序，揭示了新的适应目标，并确定了所确定的权衡的遗传基础。
Trade-offs constrain the improvement of performance of multiple traits simultaneously. Such trade-offs define Pareto fronts, which represent a set of optimal individuals that cannot be improved in any one trait without reducing performance in another. Surprisingly, experimental evolution often yields genotypes with improved performance in all measured traits, perhaps indicating an absence of trade-offs at least in the short term. Here we densely sample adaptive mutations in Saccharomyces cerevisiae to ask whether first-step adaptive mutations result in trade-offs during the growth cycle. We isolated thousands of adaptive clones evolved under carefully chosen conditions and quantified their performances in each part of the growth cycle. We too find that some first-step adaptive mutations can improve all traits to a modest extent. However, our dense sampling allowed us to identify trade-offs and establish the existence of Pareto fronts between fermentation and respiration, and between respiration and stationary phases. Moreover, we establish that no single mutation in the ancestral genome can circumvent the detected trade-offs. Finally, we sequenced hundreds of these adaptive clones, revealing new targets of adaptation and defining the genetic basis of the identified trade-offs.