瑞士苏黎世大学Andreas Wagner研究团队揭示了选择如何通过突变来增强蛋白质的演化能力。2020年12月4日，国际知名学术期刊《科学》发表了这一成果。

为了研究选择强度如何影响可演化性，研究人员对黄色荧光蛋白群体进行了不同选择机制下的定向演化，然后将其进化为绿色荧光的新表型。处于强烈选择黄色表型状态的群体向绿色表型演化最快。它们这样做是通过积累能够增加强度和折叠性的突变来实现的。在弱选择下，新功能化的突变起初频率更高，但更频繁的有害突变破坏了它们最终的成功。

这些实验表明选择如何通过增强鲁棒性来增强演化能力，并为演化成功创造必要条件。

研究人员介绍，自然选择可以促进或阻碍群体的演化能力，即演化出新的和适应性表型的能力，但其背后的机制却知之甚少。

附：英文原文

Title: Selection enhances protein evolvability by increasing mutational robustness and foldability

Author: Jia Zheng, Ning Guo, Andreas Wagner

Issue&Volume: 2020/12/04

Abstract: Natural selection can promote or hinder a population’s evolvability—the ability to evolve new and adaptive phenotypes—but the underlying mechanisms are poorly understood. To examine how the strength of selection affects evolvability, we subjected populations of yellow fluorescent protein to directed evolution under different selection regimes and then evolved them toward the new phenotype of green fluorescence. Populations under strong selection for the yellow phenotype evolved the green phenotype most rapidly. They did so by accumulating mutations that increase both robustness to mutations and foldability. Under weak selection, neofunctionalizing mutations rose to higher frequency at first, but more frequent deleterious mutations undermined their eventual success. Our experiments show how selection can enhance evolvability by enhancing robustness and create the conditions necessary for evolutionary success.

DOI: 10.1126/science.abb5962

Source: https://science.sciencemag.org/content/370/6521/eabb5962