Data from: Mutation dynamics and fitness effects followed in single cells

Mutations have been investigated for more than a century but remain
difficult to observe directly in single cells, which limits the
characterization of their dynamics and fitness effects. By combining
microfluidics, time-lapse imaging, and a fluorescent tag of the mismatch
repair system in Escherichia coli, we visualized the emergence of
mutations in single cells, revealing Poissonian dynamics. Concomitantly,
we tracked the growth and life span of single cells, accumulating ~20,000
mutations genome-wide over hundreds of generations. This analysis revealed
that 1% of mutations were lethal; nonlethal mutations displayed a
heavy-tailed distribution of fitness effects and were dominated by
quasi-neutral mutations with an average cost of 0.3%. Our approach has
enabled the investigation of single-cell individuality in mutation rate,
mutation fitness costs, and mutation interactions.

突变的研究已持续逾一个世纪，但在单细胞中直接观测仍具挑战，这限制了对其动态变化及适合度效应的表征。通过结合微流控技术、延时成像及大肠杆菌（Escherichia coli）错配修复系统的荧光标记，我们实现了单细胞中突变发生的可视化，揭示其符合泊松动力学特征。同时，我们追踪了单细胞的生长与寿命，在数百代内积累了全基因组范围内约20,000个突变。分析显示，1%的突变具有致死性；非致死突变的适合度效应呈重尾分布，且以平均代价为0.3%的准中性突变为主导。我们的方法为研究突变率、突变适合度代价及突变间相互作用中的单细胞个体差异提供了可能。