Carja Oana, Liberman Uri, Feldman Marcus W
Department of Biology, Stanford University, Stanford, California 94305-5020.
Genetics. 2014 Apr;196(4):1185-97. doi: 10.1534/genetics.114.161364. Epub 2014 Feb 4.
Stochastic switching is an example of phenotypic bet hedging, where offspring can express a phenotype different from that of their parents. Phenotypic switching is well documented in viruses, yeast, and bacteria and has been extensively studied when the selection pressures vary through time. However, there has been little work on the evolution of phenotypic switching under both spatially and temporally fluctuating selection pressures. Here we use a population genetic model to explore the interaction of temporal and spatial variation in determining the evolutionary dynamics of phenotypic switching. We find that the stable switching rate is mainly determined by the rate of environmental change and the migration rate. This stable rate is also a decreasing function of the recombination rate, although this is a weaker effect than those of either the period of environmental change or the migration rate. This study highlights the interplay of spatial and temporal environmental variability, offering new insights into how migration can influence the evolution of phenotypic switching rates, mutation rates, or other sources of phenotypic variation.
随机切换是表型风险对冲的一个例子，在这种情况下，后代可以表达与其父母不同的表型。表型切换在病毒、酵母和细菌中已有充分记录，并且在选择压力随时间变化时已得到广泛研究。然而，在空间和时间波动的选择压力下，关于表型切换的进化研究很少。在这里，我们使用种群遗传模型来探索时间和空间变化在决定表型切换进化动态中的相互作用。我们发现，稳定的切换率主要由环境变化率和迁移率决定。这个稳定率也是重组率的递减函数，尽管这种影响比环境变化周期或迁移率的影响要弱。这项研究突出了空间和时间环境变异性的相互作用，为迁移如何影响表型切换率、突变率或其他表型变异来源的进化提供了新的见解。
