Data from: Loss of growth homeostasis by genetic decoupling of cell division from biomass growth: implication for size control mechanisms

Growing cells adjust their division time with biomass accumulation to maintain growth homeostasis. Size control mechanisms, such as the size checkpoint, provide an inherent coupling of growth and division by gating certain cell cycle transitions based on cell size. We describe genetic manipulations that decouple cell division from cell size, leading to the loss of growth homeostasis, with cells becoming progressively smaller or progressively larger until arresting. This was achieved by modulating glucose influx independently of external glucose. Division rate followed glucose influx, while volume growth was largely defined by external glucose. Therefore, the coordination of size and division observed in wild‐type cells reflects tuning of two parallel processes, which is only refined by an inherent feedback‐dependent coupling. We present a class of size control models explaining the observed breakdowns of growth homeostasis.

增殖细胞可随生物量积累调整分裂时长，以维持生长稳态（growth homeostasis）。诸如细胞大小检查点（size checkpoint）这类大小调控机制，可通过基于细胞尺寸对部分细胞周期进程进行门控，实现生长与分裂的内在耦联。本研究描述了可将细胞分裂与细胞尺寸解耦的遗传操作，该操作会导致生长稳态丧失，使细胞持续变小或持续变大，直至增殖停滞。该表型可通过独立于胞外葡萄糖浓度调控葡萄糖内流（glucose influx）实现。细胞分裂速率随葡萄糖内流变化，而细胞体积增长则主要由胞外葡萄糖浓度决定。因此，野生型细胞中观察到的尺寸与分裂的协调关系，实则反映了两个平行过程的协同调控，而这种协调仅能通过内在的反馈依赖性耦联得以优化。我们提出了一类可解释上述生长稳态破坏现象的尺寸调控模型。