Microbial Morphogenesis and Growth Laboratory, Institut Pasteur, Paris, France.
Department of Environmental Microbiology, Dübendorf, Switzerland.
Elife. 2021 Oct 6;10:e67495. doi: 10.7554/eLife.67495.
Cells must control the cell cycle to ensure that key processes are brought to completion. In , it is controversial whether cell division is tied to chromosome replication or to a replication-independent inter-division process. A recent model suggests instead that processes may limit cell division with comparable odds in single cells. Here, we tested this possibility experimentally by monitoring single-cell division and replication over multiple generations at slow growth. We then perturbed cell width, causing an increase of the time between replication termination and division. As a consequence, replication became decreasingly limiting for cell division, while correlations between birth and division and between subsequent replication-initiation events were maintained. Our experiments support the hypothesis that both chromosome replication and a replication-independent inter-division process can limit cell division: the two processes have balanced contributions in non-perturbed cells, while our width perturbations increase the odds of the replication-independent process being limiting.
细胞必须控制细胞周期，以确保关键过程得以完成。在这个过程中，细胞分裂是与染色体复制相关，还是与独立于复制的分裂前过程相关，这一直存在争议。最近的一个模型表明，分裂前过程可能会以相当的概率限制单细胞分裂。在这里，我们通过在缓慢生长的条件下，在多个世代中监测单细胞的分裂和复制，来实验性地检验这种可能性。然后，我们扰动细胞宽度，导致复制终止和分裂之间的时间增加。结果，复制对细胞分裂的限制作用越来越小，而出生和分裂之间以及随后的复制起始事件之间的相关性仍然保持。我们的实验支持这样一种假设，即染色体复制和独立于复制的分裂前过程都可以限制细胞分裂：在未受干扰的细胞中，这两个过程的贡献是平衡的，而我们的宽度干扰增加了独立于复制的过程受到限制的可能性。
