Growth laws emerging from studies of cell populations provide essential constraints on the global mechanisms that coordinate cell growth1-3. The foundation of bacterial cell cycle studies relies on two interconnected dogmas that were proposed more than 50 years ago-the Schaechter-Maaloe-Kjeldgaard growth law that relates cell mass to growth rate1 and Donachie's hypothesis of a growth-rate-independent initiation mass4. These dogmas spurred many efforts to understand their molecular bases and physiological consequences5-14. Although they are generally accepted in the fast-growth regime, that is, for doubling times below 1 h, extension of these dogmas to the slow-growth regime has not been consistently achieved. Here, through a quantitative physiological study of Escherichia coli cell cycles over an extensive range of growth rates, we report that neither dogma holds in either the slow- or fast-growth regime. In their stead, linear relations between the cell mass and the rate of chromosome replication-segregation were found across the range of growth rates. These relations led us to propose an integral-threshold model in which the cell cycle is controlled by a licensing process, the rate of which is related in a simple way to chromosomal dynamics. These results provide a quantitative basis for predictive understanding of cell growth-cell cycle relationships.

中文翻译：

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大肠杆菌中细胞生长和细胞周期的一般定量关系。

细胞群研究中出现的生长规律为协调细胞生长的全局机制提供了必要的限制1-3。细菌细胞周期研究的基础依赖于 50 多年前提出的两个相互关联的教条——Schaechter-Maaloe-Kjeldgaard 生长定律，将细胞质量与生长速率联系起来 1 和 Donachie 的与生长速率无关的起始质量的假设 4。这些教条激发了许多努力来了解它们的分子基础和生理后果5-14。尽管它们在快速增长状态下被普遍接受，即倍增时间低于 1 小时，但这些教条向缓慢增长状态的扩展并没有始终如一地实现。在这里，通过对大范围生长速率下的大肠杆菌细胞周期的定量生理学研究，我们报告说，无论是缓慢增长还是快速增长，这两种教条都不成立。取而代之的是，在生长速率范围内发现了细胞质量与染色体复制分离速率之间的线性关系。这些关系使我们提出了一个积分阈值模型，其中细胞周期由许可过程控制，许可过程的速率以简单的方式与染色体动力学相关。这些结果为预测理解细胞生长-细胞周期关系提供了定量基础。这些关系使我们提出了一个积分阈值模型，其中细胞周期由许可过程控制，许可过程的速率以简单的方式与染色体动力学相关。这些结果为预测理解细胞生长-细胞周期关系提供了定量基础。这些关系使我们提出了一个积分阈值模型，其中细胞周期由许可过程控制，许可过程的速率以简单的方式与染色体动力学相关。这些结果为预测理解细胞生长-细胞周期关系提供了定量基础。