Noise-driven growth rate gain in clonal cellular populations
Noise-driven growth rate gain in clonal cellular populations
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DOI：
10.1073/pnas.1519412113
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发表时间：
2016-03-22
影响因子：
11.1
通讯作者：
Wakamoto, Yuichi
中科院分区：
文献类型：
--
作者：
Hashimoto, Mikihiro;Nozoe, Takashi;Wakamoto, Yuichi
自然界和实验室中的细胞群体由表型异质的个体组成，这些个体相互竞争，导致复杂的群体动态。基于异质单细胞动力学知识预测种群增长特征仍然具有挑战性。通过观察数百代的单细胞分辨率的细胞群，我们发现，生长噪音导致大肠杆菌的克隆种群翻了一番，比其组成的单细胞在广泛的平衡生长条件下的平均倍增时间更快。我们表明，人口水平的增长率增益以及年龄结构的人口和细胞系的竞争是可预测的。此外，我们从理论上揭示了增长率增益可以与谱系生成时间分布的相对熵。出乎意料的是，我们发现一个经验之间的线性关系的平均值和方差的生成时间的条件，这提供了一个一般的约束最大的增长率。总之，这些结果证明了噪音对人口增长的根本好处，并确定了一个增长规律，为增殖设定了“速度限制”。
Cellular populations in both nature and the laboratory are composed of phenotypically heterogeneous individuals that compete with each other resulting in complex population dynamics. Predicting population growth characteristics based on knowledge of heterogeneous single-cell dynamics remains challenging. By observing groups of cells for hundreds of generations at single-cell resolution, we reveal that growth noise causes clonal populations of Escherichia coli to double faster than the mean doubling time of their constituent single cells across a broad set of balanced-growth conditions. We show that the population-level growth rate gain as well as age structures of populations and of cell lineages in competition are predictable. Furthermore, we theoretically reveal that the growth rate gain can be linked with the relative entropy of lineage generation time distributions. Unexpectedly, we find an empirical linear relation between the means and the variances of generation times across conditions, which provides a general constraint on maximal growth rates. Together, these results demonstrate a fundamental benefit of noise for population growth, and identify a growth law that sets a "speed limit" for proliferation.