Host-parasite coevolution promotes innovation through deformations in fitness landscapes

eLife

Einat S Tamar¹  Roy Kishony¹  Benjamin Kerr²  Luis Zaman³  Alita R Burmeister⁴  Justin R Meyer⁵  Hannah M Strobel⁵  Jenna Gallie⁶  Animesh Gupta⁷ 

[1] Department of Biology, Technion – Israel Institute of Technology, Haifa, Israel;Department of Biology, University of Washington, Seattle, United States;Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, United States;Department of Ecology and Evolutionary Biology, Yale University, New Haven, United States;Department of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, United States;Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany;Department of Physics, University of California San Diego, La Jolla, United States;

关键词: fitness landscapes;    coevolution;    bacteriophage;    lambda;    arms race;   

DOI  :  10.7554/eLife.76162

来源: DOAJ

【 摘 要 】

During the struggle for survival, populations occasionally evolve new functions that give them access to untapped ecological opportunities. Theory suggests that coevolution between species can promote the evolution of such innovations by deforming fitness landscapes in ways that open new adaptive pathways. We directly tested this idea by using high-throughput gene editing-phenotyping technology (MAGE-Seq) to measure the fitness landscape of a virus, bacteriophage λ, as it coevolved with its host, the bacterium Escherichia coli. An analysis of the empirical fitness landscape revealed mutation-by-mutation-by-host-genotype interactions that demonstrate coevolution modified the contours of λ’s landscape. Computer simulations of λ’s evolution on a static versus shifting fitness landscape showed that the changes in contours increased λ’s chances of evolving the ability to use a new host receptor. By coupling sequencing and pairwise competition experiments, we demonstrated that the first mutation λ evolved en route to the innovation would only evolve in the presence of the ancestral host, whereas later steps in λ’s evolution required the shift to a resistant host. When time-shift replays of the coevolution experiment were run where host evolution was artificially accelerated, λ did not innovate to use the new receptor. This study provides direct evidence for the role of coevolution in driving evolutionary novelty and provides a quantitative framework for predicting evolution in coevolving ecological communities.

【 授权许可】

Unknown