The evolution of coexistence from competition in experimental co-cultures of Escherichia coli and Saccharomyces cerevisiae
The evolution of coexistence from competition in experimental co-cultures of Escherichia coli and Saccharomyces cerevisiae
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DOI：
10.1038/s41396-020-00810-z
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发表时间：
2020-10-22
期刊：
影响因子：
11
通讯作者：
McDonald, Michael J.
中科院分区：
文献类型：
--
作者：
Barber, Jake N.;Sezmis, Aysha L.;McDonald, Michael J.
微生物群落由许多在小空间尺度上共存的物种组成。这很难解释，因为许多物种间的相互作用是竞争性的，生态理论预测，一个物种将导致竞争同一资源的另一个物种的灭绝。相反，进化理论认为，自然选择可以通过驱动竞争物种使用不重叠的资源来实现共存。然而，与竞争排斥的速度相比，从进化上逃脱灭绝的速度可能很慢。在这里，我们使用大肠杆菌和酿酒酵母的实验共培养来研究竞争资源的物种共存的进化。我们发现，虽然大肠杆菌通常在共培养中胜过酿酒酵母，但少数群体在经历了大约 1000 代的共同进化后进化出了稳定的共存。我们对酿酒酵母和大肠杆菌群体进行了测序，鉴定了多重命中基因，并将这些基因的等位基因改造到几个遗传背景中，发现一些突变改变了大肠杆菌和酿酒酵母之间的相互作用。总之，我们的数据表明，共存可以从两个没有共同进化历史的物种之间的激烈竞争中重新进化。
Microbial communities are comprised of many species that coexist on small spatial scales. This is difficult to explain because many interspecies interactions are competitive, and ecological theory predicts that one species will drive the extinction of another species that competes for the same resource. Conversely, evolutionary theory proposes that natural selection can lead to coexistence by driving competing species to use non-overlapping resources. However, evolutionary escape from extinction may be slow compared to the rate of competitive exclusion. Here, we use experimental co-cultures of Escherichia coli and Saccharomyces cerevisiae to study the evolution of coexistence in species that compete for resources. We find that while E. coli usually outcompetes S. cerevisiae in co-culture, a few populations evolved stable coexistence after similar to 1000 generations of coevolution. We sequenced S. cerevisiae and E. coli populations, identified multi-hit genes, and engineered alleles from these genes into several genetic backgrounds, finding that some mutations modified interactions between E. coli and S. cerevisiae. Together, our data demonstrate that coexistence can evolve, de novo, from intense competition between two species with no history of coevolution.