Bistability is a common mechanism to ensure robust and irreversible cell cycle transitions. Whenever biological parameters or external conditions change such that a threshold is crossed, the system abruptly switches between different cell cycle states. Experimental studies have uncovered mechanisms that can make the shape of the bistable response curve change dynamically in time. Here, we show how such a dynamically changing bistable switch can provide a cell with better control over the timing of cell cycle transitions. Moreover, cell cycle oscillations built on bistable switches are more robust when the bistability is modulated in time. Our results are not specific to cell cycle models and may apply to other bistable systems in which the bistable response curve is time-dependent.

双稳态是确保鲁棒和不可逆的细胞周期转换的常见机制。每当生物学参数或外部条件发生变化从而超过阈值时，系统都会在不同的细胞周期状态之间突然切换。实验研究发现了可以使双稳态响应曲线的形状随时间动态变化的机制。在这里，我们展示了这种动态变化的双稳态开关如何为电池提供对电池周期转换时序的更好控制。此外，当双稳态被及时调制时，建立在双稳态开关上的细胞周期振荡更加鲁棒。我们的结果并非特定于细胞周期模型，可能适用于双稳态响应曲线与时间有关的其他双稳态系统。