论文标题
人口增长率和细胞大小分布的渐近解耦
Asymptotic decoupling of population growth rate and cell size distribution
论文作者
论文摘要
各个细菌细胞生长的速率取决于细胞成分（例如核糖体和蛋白质）的浓度。这些浓度随着时间的流逝不断波动，并从母亲到子细胞遗传，从而导致各代细胞的生长速率之间的相关性。细胞的分裂尺寸也是随机的，并且由于一种称为细胞大小调节的现象，各代相关。生长和分裂过程的波动和相关性影响成倍增长的培养物的种群动态。在这里，我们为细胞的种群动力学提供了分析解决方案，并连续波动的生长速率与细胞大小调节的通用模型相结合。我们表明，在平衡的增长中，生长和分裂过程的影响是脱成的。人口增长率仅取决于单细胞生长速率过程，人口细胞的大小分布仅取决于分裂和细胞大小调节的模型。人口增长率始终高于平均单细胞增长率，并且差异随增长率变异性及其相关时间而增加。这种差异还为人口达到稳态的时间范围。我们为在这种稳定状态的方法期间提供了分析解决方案，以实现人口增长率和大小分布的行进波的振荡。
The rate at which individual bacterial cells grow depends on the concentrations of cellular components such as ribosomes and proteins. These concentrations continuously fluctuate over time and are inherited from mother to daughter cells, leading to correlations between the growth rates of cells across generations. Division sizes of cells are also stochastic and correlated across generations due to a phenomenon known as cell size regulation. Fluctuations and correlations from both growth and division processes affect the population dynamics of an exponentially growing culture. Here, we provide analytic solutions for the population dynamics of cells with continuously fluctuating growth rates coupled with a generic model of cell-size regulation. We show that in balanced growth, the effects of growth and division processes decouple; the population growth rate only depends on the single-cell growth rate process, and the population cell size distribution only depends on the model of division and cell size regulation. The population growth rate is always higher than the average single-cell growth rate, and the difference increases with growth rate variability and its correlation time. This difference also sets the timescale for the population to reach its steady state. We provide analytical solutions for oscillations in population growth rate and traveling waves in size distribution during this approach to the steady state.
