Interdependence of behavioural variability and response to small stimuli in bacteria.
Interdependence of behavioural variability and response to small stimuli in bacteria.
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作者：
大肠杆菌中控制细菌运动的趋化信号网络是信号转导的经典模型系统。这一途径调节鞭毛马达的行为，将细菌推向化学引诱剂的来源。虽然这个系统对环境变化的反应放松到稳定状态，但趋化网络中的信号事件是嘈杂的，即使在没有刺激的情况下，也会导致运动行为的巨大时间变化。事实上，同一个信号网络同时控制着行为的可变性和细胞的反应，这一事实提出了一个问题，即这两个特征是否独立。在这里，我们在实验上建立了活细菌趋化系统中的波动-反应关系。利用这种关系，我们证明了从刺激前测量的行为变异性来推断细胞反应的可能性。在监测单个细菌马达刺激前和刺激后的切换行为时，我们发现变异性与细胞不同功能状态的反应时间呈线性关系。这项研究强调，基本的涨落-响应关系并不局限于热力学平衡的物理系统，而是可扩展到活细胞。这种关系不仅意味着行为可变性和细胞反应是耦合的特征，而且还提供了一个一般框架，以检验网络设计的选择如何塑造这种相互依赖。
The chemotaxis signalling network in E. coli that controls the locomotion of bacteria is a classic model system for signal transduction. This pathway modulates the behaviour of flagellar motors to propel bacteria towards sources of chemical attractants. Although this system relaxes to a steady-state in response to environmental changes, the signalling events within the chemotaxis network are noisy and cause large temporal variations of the motor behaviour even in the absence of stimulus. The fact that the same signalling network governs both behavioural variability and cellular response raises the question of whether these two traits are independent. Here, we experimentally establish a fluctuation-response relationship in the chemotaxis system of living bacteria. Using this relationship, we demonstrate the possibility of inferring the cellular response from the behavioural variability measured before stimulus. In monitoring pre- and post-stimulus switching behaviour of individual bacterial motors, we found that variability scales linearly with the response time for different functioning states of the cell. This study highlights that the fundamental fluctuation-response relationship is not constrained to physical systems at thermodynamic equilibrium but is extensible to living cells. Such a relationship not only implies that behavioural variability and cellular response are coupled traits, but also provides a general framework to examine how the selection of a network design shapes this interdependence.
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影响因子：
64.8
作者：
Alon, U;Surette, MG;Leibler, S
通讯作者：
Leibler, S
影响因子：
64.8
作者：
Barkai, N;Leibler, S
通讯作者：
Leibler, S
影响因子：
8.6
作者：
Dorignac, J;Kalinowski, A;Mohanty, P
通讯作者：
Mohanty, P
影响因子：
8.6
作者：
Cugliandolo, LF;Dean, DS;Kurchan, J
通讯作者：
Kurchan, J
DOI：
10.1088/1742-5468/2008/08/p08005
发表时间：
2008-08-01
影响因子：
2.4
作者：
Chetrite, Raphael;Falkovich, Gregory;Gawedzki, Krzysztof
通讯作者：
Gawedzki, Krzysztof