Espinosa-Soto Carlos, Hernández Ulises, Posadas-García Yuridia S
Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
Evol Dev. 2021 Sep;23(5):459-473. doi: 10.1111/ede.12391. Epub 2021 Aug 29.
A new phenotypic variant may appear first in organisms through plasticity, that is, as a response to an environmental signal or other nongenetic perturbation. If such trait is beneficial, selection may increase the frequency of alleles that enable and facilitate its development. Thus, genes may take control of such traits, decreasing dependence on nongenetic disturbances, in a process called genetic assimilation. Despite an increasing amount of empirical studies supporting genetic assimilation, its significance is still controversial. Whether genetic assimilation is widespread depends, to a great extent, on how easily mutation and recombination reduce the trait's dependence on nongenetic perturbations. Previous research suggests that this is the case for mutations. Here we use simulations of gene regulatory network dynamics to address this issue with respect to recombination. We find that recombinant offspring of parents that produce a new phenotype through plasticity are more likely to produce the same phenotype without requiring any perturbation. They are also prone to preserve the ability to produce that phenotype after genetic and nongenetic perturbations. Our work also suggests that ancestral plasticity can play an important role for setting the course that evolution takes. In sum, our results indicate that the manner in which phenotypic variation maps unto genetic variation facilitates evolution through genetic assimilation in gene regulatory networks. Thus, we contend that the importance of this evolutionary mechanism should not be easily neglected.
一种新的表型变异可能首先通过可塑性出现在生物体中，也就是说，作为对环境信号或其他非遗传扰动的一种反应。如果这种性状是有益的，选择可能会增加使该性状得以产生并促进其发展的等位基因的频率。因此，基因可能会控制这种性状，在一个称为遗传同化的过程中减少对非遗传干扰的依赖。尽管有越来越多的实证研究支持遗传同化，但其重要性仍存在争议。遗传同化是否广泛存在在很大程度上取决于突变和重组降低性状对非遗传扰动的依赖的难易程度。先前的研究表明突变的情况就是如此。在这里，我们使用基因调控网络动态模拟来解决关于重组的这个问题。我们发现，通过可塑性产生新表型的亲本的重组后代更有可能在不需要任何扰动的情况下产生相同的表型。它们在遗传和非遗传扰动后也倾向于保留产生该表型的能力。我们的工作还表明，祖先的可塑性可以在设定进化路径方面发挥重要作用。总之，我们的结果表明，表型变异映射到遗传变异的方式通过基因调控网络中的遗传同化促进了进化。因此，我们认为这种进化机制的重要性不应被轻易忽视。
