Bistability and hysteresis in epigenetic regulation of the lactose operon. Since Delbruck, a long series of ignored models
Bistability and hysteresis in epigenetic regulation of the lactose operon. Since Delbruck, a long series of ignored models
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DOI：
10.1170/t667
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发表时间：
2005-01-01
影响因子：
1.6
通讯作者：
Guespin-Michel, J
中科院分区：
文献类型：
--
作者：
Laurent, M;Charvin, G;Guespin-Michel, J
双稳态是指系统以“全有或全无”的方式在可选的稳态之间切换的能力。这个强大的概念源于对驱动开放系统的非线性方程的分析。这是与一类特定的动态结构相关的各种监管模式之一，格兰斯多夫和普里戈金将其命名为“耗散结构”。另一种状态之间的不连续转变的想法最早由德尔布鲁克在1949年提出。科恩和霍里巴塔以及诺维克和韦纳证实，这种转变发生在十年后对乳糖操纵子进行的实验中。用非线性微分方程组建模使模拟乳胶操纵子的动态行为成为可能，而用异步逻辑分析建模阐明了正反馈电路在多稳态的出现中所起的决定性作用。然而，这些研究在很大程度上被忽视了，直到最近证明了乳胶操纵子的不同状态之间的双稳态转变的滞后性。正如Delbruck最初提出的那样，细菌采用的乳糖消耗模式是由表观遗传而不是遗传控制的：真正的关键决定因素是环境变量相对于操纵子结构成分的变化方向。
Bistability is the capacity of a system to switch in an "all-or-none" manner between alternative steady states. This powerful concept originates from the analysis of non-linear equations driving open systems. It is one of the various patterns of regulation associated with a particular class of dynamic structures that Glansdorff and Prigogine baptised "dissipative structures". The idea of discontinuous transitions between alternative states was first formulated much earlier, by Delbruck, in 1949. Cohn and Horibata and Novick and Weiner confirmed that such transitions occur in experiments on the lactose operon carried out ten years later. Modelling with non-linear differential equations made it possible to simulate the dynamic behaviour of the lac operon, and modelling by asynchronous logical analysis elucidated the determinant role played by positive feedback circuits in the emergence of multistationarity. Nevertheless, these studies were largely ignored until the recent demonstration of the hysteretic nature of the bistable transition between alternative states of the lac operon. As originally suggested by Delbruck, the pattern of lactose consumption adopted by the bacterium is controlled epigenetically rather than genetically: the true key determinant is the direction of change of an environmental variable with respect to the structural components of the operon.