Adaptation dynamics in stressful environments from standing genetic variation in S. cerevisiae. Adaptation dynamics in stressful environments

Adaptation, both at the phenotypic and genetic level, is often assumed but rarely observed in real time. Thus, we usually know little about the timing and dynamics of adaptation, and the underlying genetic mechanisms. Here, we use the power of experimental evolution with Baker’s yeast and whole population sequencing, to track fitness and genomic changes for 1000 asexual generations in four divergent, stressful environments. Instead of clonal starting conditions, we used outcrossed founder populations containing standing genetic variation.

表型与遗传层面的适应性演化通常仅为学界的预设假设，却极少能被实时观测到。因此，我们对适应性演化的发生时序、动态过程及其背后的潜在遗传机制往往知之甚少。本研究借助酿酒酵母（Baker’s yeast）实验演化模型与全种群测序（whole population sequencing）技术的优势，对4个差异化胁迫环境下共计1000个无性世代的种群适合度（fitness）与基因组变化进行了追踪。本研究未采用克隆起始种群（clonal starting conditions）作为实验初始条件，而是选用携带现存遗传变异（standing genetic variation）的异交创始种群（outcrossed founder populations）开展实验。