Adaptive response of a gene network to environmental changes by fitness-induced attractor selection.
Adaptive response of a gene network to environmental changes by fitness-induced attractor selection.
复制标题
基因网络对环境变化的自适应反应通过健身诱导的吸引子选择。
DOI：
10.1371/journal.pone.0000049
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发表时间：
2006-12-20
期刊：
影响因子：
3.7
通讯作者：
Yomo, Tetsuya
中科院分区：
文献类型：
--
作者：
Kashiwagi, Akiko;Urabe, Itaru;Kaneko, Kunihiko;Yomo, Tetsuya
细胞在各种稳定的遗传程序（吸引子）之间切换以适应环境条件。信号转导机制有效地将环境变化传递给基因调控装置，以表达适当的遗传程序。然而，由于环境条件的数量远大于可用遗传程序的数量，因此细胞可以在大量条件下利用相同的遗传程序，因此它可能无法针对每种环境条件（特别是那些很少遇到的环境条件）进化出信号传导途径。在这里，我们表明，在没有信号转导的情况下，可以切换到表达适应外部条件的基因的适当吸引子状态。在大肠杆菌的合成双稳态基因开关中，相互抑制的操纵子控制两种替代营养环境所需的两个基因的表达，细胞可靠地选择了由基因表达噪声驱动的“适应性吸引子”。数学模型表明，要避免“非适应性吸引子”，因为在不利条件下，细胞活性较低，从而抑制 mRNA 代谢，导致基因表达出现较大波动。这反过来又使得非自适应状态变得不太稳定。尽管吸引子选择不如通过专用级联的信号转导那么有效，但它简单且稳健，并且可能代表了自适应响应的原始机制，该机制先于针对经常遇到的环境变化的信号级联的进化。
Cells switch between various stable genetic programs (attractors) to accommodate environmental conditions. Signal transduction machineries efficiently convey environmental changes to the gene regulation apparatus in order to express the appropriate genetic program. However, since the number of environmental conditions is much larger than that of available genetic programs so that the cell may utilize the same genetic program for a large set of conditions, it may not have evolved a signaling pathway for every environmental condition, notably those that are rarely encountered. Here we show that in the absence of signal transduction, switching to the appropriate attractor state expressing the genes that afford adaptation to the external condition can occur. In a synthetic bistable gene switch in Escherichia coli in which mutually inhibitory operons govern the expression of two genes required in two alternative nutritional environments, cells reliably selected the “adaptive attractor” driven by gene expression noise. A mathematical model suggests that the “non-adaptive attractor” is avoided because in unfavorable conditions, cellular activity is lower, which suppresses mRNA metabolism, leading to larger fluctuations in gene expression. This, in turn, renders the non-adaptive state less stable. Although attractor selection is not as efficient as signal transduction via a dedicated cascade, it is simple and robust, and may represent a primordial mechanism for adaptive responses that preceded the evolution of signaling cascades for the frequently encountered environmental changes.
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DOI：
10.2142/biophysics.1.25
发表时间：
2005
期刊：
Biophysics (Nagoya-shi, Japan)
影响因子：
--
作者：
Furusawa C;Suzuki T;Kashiwagi A;Yomo T;Kaneko K
通讯作者：
Kaneko K
影响因子：
9.9
作者：
Dublanche, Yann;Michalodimitrakis, Konstantinos;Serrano, Luis
通讯作者：
Serrano, Luis
影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
DOI：
10.1073/pnas.040411297
发表时间：
2000-02-29
影响因子：
11.1
作者：
Hasty, J;Pradines, J;Collins, JJ
通讯作者：
Collins, JJ
DOI：
10.1073/pnas.0408507102
发表时间：
2005-03-08
影响因子：
11.1
作者：
Hooshangi, S;Thiberge, S;Weiss, R
通讯作者：
Weiss, R