Adaptive prediction of environmental changes by microorganisms
Adaptive prediction of environmental changes by microorganisms
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DOI：
10.1038/nature08112
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发表时间：
2009-07-09
期刊：
影响因子：
64.8
通讯作者：
Pilpel, Yitzhak
中科院分区：
文献类型：
--
作者：
Mitchell, Amir;Romano, Gal H.;Pilpel, Yitzhak
一些微生物的自然栖息地可能会不稳定地波动，而另一些微生物的自然栖息地更可预测，为下一次环境变化提供了提前准备的机会。与经典的巴甫洛夫条件反射类似，微生物可能已经进化到通过适应它们出现的时间顺序来预测环境刺激。在这里，我们提出了两种模式微生物--大肠杆菌和酿酒酵母--环境变化预测的证据。我们表明，预期是一种适应性特征，因为预先暴露于生态中通常出现的早期刺激会改善有机体在遇到第二个刺激时的适应性。此外，我们观察到在实验室进化实验中反复暴露于第一个刺激下的大肠杆菌菌株条件反应的丧失。对分子水平的关注揭示了刺激的自然时间顺序嵌入到调控网络的线路中-早期刺激预先诱导后来的刺激所需的基因，而后来的刺激只诱导应对它们所需的基因。我们的工作表明，环境预期是一种适应性特征，在进化过程中被反复选择，因此可能在生物学中无处不在。
Natural habitats of some microorganisms may fluctuate erratically, whereas others, which are more predictable, offer the opportunity to prepare in advance for the next environmental change. In analogy to classical Pavlovian conditioning, microorganisms may have evolved to anticipate environmental stimuli by adapting to their temporal order of appearance. Here we present evidence for environmental change anticipation in two model microorganisms, Escherichia coli and Saccharomyces cerevisiae. We show that anticipation is an adaptive trait, because pre-exposure to the stimulus that typically appears early in the ecology improves the organism's fitness when encountered with a second stimulus. Additionally, we observe loss of the conditioned response in E. coli strains that were repeatedly exposed in a laboratory evolution experiment only to the first stimulus. Focusing on the molecular level reveals that the natural temporal order of stimuli is embedded in the wiring of the regulatory network-early stimuli pre-induce genes that would be needed for later ones, yet later stimuli only induce genes needed to cope with them. Our work indicates that environmental anticipation is an adaptive trait that was repeatedly selected for during evolution and thus may be ubiquitous in biology.