摘要翻译：
大肠杆菌中的细菌趋化性是研究信号转导的一个规范体系。该系统的一个显著特征是群体中的精确适应与单个细胞中的大波动细胞行为共存（Korobkova et al.2004，Nature，428，574)。利用随机模型，我们发现在实验中观察到的非刺激细胞的大的行为变异性是这种自适应系统结构的直接后果。可逆的共价修饰循环，其中甲基化和去甲基化反应拮抗地调节受体-激酶复合物的活性，运行在一级动力学范围之外。因此，控制细胞行为的受体激酶表现出乙状结肠激活曲线。这条曲线同时放大了系统内在的随机波动，延长了响应刺激的弛豫时间。由于随机波动引起大的行为变异性，而松弛时间支配着对小刺激反应的平均运行持续时间，波动行为最大的细胞也表现出最大的趋化反应。最后，对数字细菌的大规模模拟表明，趋化网络被调谐到同时优化细胞在缺乏营养物质的情况下的随机扩散和细胞对引诱剂梯度的反应。
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英文标题：
《Relationship between cellular response and behavioral variability in
  bacterial chemotaxis》
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作者：
Thierry Emonet and Philippe Cluzel
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最新提交年份：
2007
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分类信息：

一级分类：Quantitative Biology        数量生物学
二级分类：Molecular Networks        分子网络
分类描述：Gene regulation, signal transduction, proteomics, metabolomics, gene and enzymatic networks
基因调控、信号转导、蛋白质组学、代谢组学、基因和酶网络
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一级分类：Quantitative Biology        数量生物学
二级分类：Cell Behavior        细胞行为
分类描述：Cell-cell signaling and interaction; morphogenesis and development; apoptosis; bacterial conjugation; viral-host interaction; immunology
细胞-细胞信号传导及相互作用；形态发生和发育；细胞凋亡；细菌接合；病毒-宿主相互作用；免疫学
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一级分类：Quantitative Biology        数量生物学
二级分类：Other Quantitative Biology        其他定量生物学
分类描述：Work in quantitative biology that does not fit into the other q-bio classifications
不适合其他q-bio分类的定量生物学工作
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英文摘要：
  Bacterial chemotaxis in Escherichia coli is a canonical system for the study of signal transduction. A remarkable feature of this system is the coexistence of precise adaptation in population with large fluctuating cellular behavior in single cells (Korobkova et al. 2004, Nature, 428, 574). Using a stochastic model, we found that the large behavioral variability experimentally observed in non-stimulated cells is a direct consequence of the architecture of this adaptive system. Reversible covalent modification cycles, in which methylation and demethylation reactions antagonistically regulate the activity of receptor-kinase complexes, operate outside the region of first-order kinetics. As a result, the receptor-kinase that governs cellular behavior exhibits a sigmoidal activation curve. This curve simultaneously amplifies the inherent stochastic fluctuations in the system and lengthens the relaxation time in response to stimulus. Because stochastic fluctuations cause large behavioral variability and the relaxation time governs the average duration of runs in response to small stimuli, cells with the greatest fluctuating behavior also display the largest chemotactic response. Finally, Large-scale simulations of digital bacteria suggest that the chemotaxis network is tuned to simultaneously optimize the random spread of cells in absence of nutrients and the cellular response to gradients of attractant.
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PDF链接：
https://arxiv.org/pdf/0705.4635