Department of Chemistry, Rice University, Houston, Texas 77251, United States.
Center for Theoretical Biological Physics, Rice University, Houston, Texas 77251, United States.
J Phys Chem Lett. 2020 Oct 15;11(20):8777-8782. doi: 10.1021/acs.jpclett.0c02627. Epub 2020 Oct 1.
How bacteria are able to maintain their sizes remains an open question. It is believed that cells have narrow distributions of sizes as a consequence of a homeostasis that allows bacteria to function at the optimal conditions. Several phenomenological approaches to explain these observations have been presented, but the microscopic origins of the cell-size regulation are still not understood. Here, we propose a new stochastic approach to investigate the molecular mechanisms of maintaining the cell sizes in bacteria. It is argued that the cell-size regulation is a result of coupling of two stochastic processes, cell growth and division, which eliminates the need for introducing the thresholds. Dynamic properties of the system are explicitly evaluated, and it is shown that the model is consistent with the experimentally supported adder principle of the cell-size regulation. In addition, theoretical predictions agree with experimental observations on bacteria. Theoretical analysis clarifies some important features of bacterial cell growth.
细菌如何能够维持其大小仍然是一个悬而未决的问题。人们认为，细胞的大小分布很窄，这是一种内稳态的结果，使细菌能够在最佳条件下发挥作用。已经提出了几种唯象学方法来解释这些观察结果，但细胞大小调节的微观起源仍未被理解。在这里，我们提出了一种新的随机方法来研究细菌中维持细胞大小的分子机制。有人认为，细胞大小的调节是细胞生长和分裂两个随机过程耦合的结果，这消除了引入阈值的必要性。系统的动态特性被明确评估，并表明该模型与实验支持的细胞大小调节的加法器原理一致。此外，理论预测与细菌的实验观察结果一致。理论分析澄清了细菌细胞生长的一些重要特征。
