A spatial model of the evolution of quorum sensing regulating bacteriocin production
A spatial model of the evolution of quorum sensing regulating bacteriocin production
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DOI：
10.1093/beheco/arm061
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发表时间：
2007-09-01
影响因子：
2.4
通讯作者：
Hoekstra, Rolf F.
中科院分区：
文献类型：
--
作者：
Czaran, Tamas;Hoekstra, Rolf F.
像任何形式的合作行为一样，细菌中的群体感应(QS)可能容易受到作弊的影响，即那些贡献较少但仍从他人提供的好处中获利的个人。在这篇文章中，我们使用元胞自动机(CA)模型来探索QS作为空间结构种群中抗生素生产的调节机制的进化稳定性。QSG被认为是调节细菌素(抗竞争毒素)在细菌素产生能力和免疫力方面具有多型性的细菌群体中的排泄。由QS引起的社会相互作用和由细菌素排泄引起的竞争相互作用都被认为只在局部尺度上有效，即仅限于紧邻的细胞。这意味着一种相当分散的群体选择。CA模型与假设没有空间结构但在其他方面具有相同假设的模型形成对比。我们的分析预测，当产生细菌素的菌株、耐药菌株和敏感菌株之间的竞争性相互作用只涉及能够共享QS所涉及的信号和响应基因的密切相关的菌株时，QS作为细菌素分泌的调节机制在进化上是不稳定的。然而，当竞争是在不相关的菌株之间，并且QS等位基因只能由细菌素产生的菌株携带时，只要其成本很小，临界群体阈值既不太低也不太高，就可能进化出稳定的QS。
Like any form of cooperative behavior, quorum sensing (QS) in bacteria is potentially vulnerable to cheating, the occurrence of individuals that contribute less but still profit from the benefits provided by others. In this paper, we explore the evolutionary stability of QS as a regulatory mechanism of antibiotics production in a spatially structured population, using cellular automaton (CA) modeling. QSg is supposed to regulate the excretion of a bacteriocin (anticompetitor toxin) in a population of bacteria polymorphic for the ability to produce and to be immune to the bacteriocin. Both the social interactions resulting from QS and the competitive interactions resulting from the bacteriocin excretion are supposed to be only effective at the local scale, that is, restricted to the immediately neighboring cells. This implies a rather diffuse kind of group selection. The CA model is contrasted to a model assuming no spatial structure but with otherwise identical assumptions. Our analysis predicts that QS as a regulatory mechanism of bacteriocin excretion is evolutionarily unstable when the competitive interactions between bacteriocin-producing, resistant, and sensitive strains only involve closely related strains which can share the signaling and responding genes involved in QS. However, when the competition is between unrelated strains and the QS alleles can only be carried by the bacteriocin-producing strains, stable QS may evolve provided its costs are small and the critical quorum threshold is neither too low nor too high.