Trade-offs between microbial growth phases lead to frequency-dependent and non-transitive selection.
Trade-offs between microbial growth phases lead to frequency-dependent and non-transitive selection.
复制标题
微生物生长阶段之间的权衡导致频率依赖和非传递选择。
DOI：
10.1098/rspb.2017.2459
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Shakhnovich,EugeneI
中科院分区：
文献类型：
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作者：
Manhart,Michael;Adkar,BharatV;Shakhnovich,EugeneI
微生物种群中的突变不仅可以通过增加其指数增长率来增加基因型的频率，还可以通过减少其滞后时间或调整产量（资源效率）来增加基因型的频率。当我们试图预测突变的进化命运时，多种生活史特征对选择的贡献是进化生物学的一个关键问题。在这里，我们使用微生物生长模型来表明，存在与生长期和滞后期相对应的两个不同的选择组成部分，而产量则调节它们的相对重要性。当阶段之间存在权衡时，该模型预测了丰富的种群动态：由于频率依赖选择，多种菌株可以共存或表现出双稳定性，并且由于非传递选择，菌株可以进行石头剪刀布相互作用。我们描述了实现这些现象所需的环境条件和特征模式，我们证明这些特征很容易进行实验。我们的结果为分析微生物生长性状的高通量测量提供了一个理论框架，特别是解释突变体性状之间的多效性和相关性。这项工作还强调需要对简单微生物系统中的选择进行更全面的测量，在这种系统中，普通适应度景观的概念被打破。
Mutations in a microbial population can increase the frequency of a genotype not only by increasing its exponential growth rate, but also by decreasing its lag time or adjusting the yield (resource efficiency). The contribution of multiple life-history traits to selection is a critical question for evolutionary biology as we seek to predict the evolutionary fates of mutations. Here we use a model of microbial growth to show that there are two distinct components of selection corresponding to the growth and lag phases, while the yield modulates their relative importance. The model predicts rich population dynamics when there are trade-offs between phases: multiple strains can coexist or exhibit bistability due to frequency-dependent selection, and strains can engage in rock–paper–scissors interactions due to non-transitive selection. We characterize the environmental conditions and patterns of traits necessary to realize these phenomena, which we show to be readily accessible to experiments. Our results provide a theoretical framework for analysing high-throughput measurements of microbial growth traits, especially interpreting the pleiotropy and correlations between traits across mutants. This work also highlights the need for more comprehensive measurements of selection in simple microbial systems, where the concept of an ordinary fitness landscape breaks down.