Department of Physics & Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, Pennsylvania 19104-6396, USA.
Phys Rev Lett. 2019 Mar 22;122(11):118101. doi: 10.1103/PhysRevLett.122.118101.
We study the effect of correlations in generation times on the dynamics of population growth of microorganisms. We show that any nonzero correlation that is due to cell-size regulation, no matter how small, induces long-term oscillations in the population growth rate. The population only reaches its steady state when we include the often-neglected variability in the growth rates of individual cells. We discover that the relaxation timescale of the population to its steady state is determined by the distribution of single-cell growth rates and is surprisingly independent of details of the division process such as the noise in the timing of division and the mechanism of cell-size regulation. We validate the predictions of our model using existing experimental data and propose an experimental method to measure single-cell growth variability by observing how long it takes for the population to reach its steady state or balanced growth.
我们研究了代时相关性对微生物种群增长动力学的影响。结果表明，任何由细胞大小调控引起的非零相关性，无论多么小，都会导致种群增长率的长期振荡。只有当我们考虑到个体细胞增长率的变化时，种群才会达到稳定状态。我们发现，种群达到稳定状态的弛豫时间尺度取决于单细胞生长率的分布，而且令人惊讶的是，它与分裂过程的细节无关，如分裂时间的噪声和细胞大小调控的机制。我们使用现有的实验数据验证了我们模型的预测，并提出了一种通过观察种群达到稳定状态或平衡生长所需的时间来测量单细胞生长变异性的实验方法。
