Invasion and fixation of microbial dormancy traits under competitive pressure

STOCHASTIC PROCESSES AND THEIR APPLICATIONS

卷:130

Article

Blath, Jochen¹  Tobias, Andras¹ 

[1] TU Berlin, Str 17 Juni 136, D-10623 Berlin, Germany

关键词: Dormancy;    Seed bank;    Competition-induced switching;    Individual-based stochastic population model;    Multitype branching process;    Lotka-Volterra type system;   

DOI  :  10.1016/j.spa.2020.07.018

来源: Elsevier

【 摘 要 】

Microbial dormancy is an evolutionary trait that has emerged independently at various positions across the tree of life. It describes the ability of a microorganism to switch to a metabolically inactive state that can withstand unfavourable conditions. However, maintaining such a trait requires additional resources that could otherwise be used to increase e.g. reproductive rates. In this paper, we aim for gaining a basic understanding under which conditions maintaining a seed bank of dormant individuals provides a fitness advantage when facing resource limitations and competition for resources among individuals (in an otherwise stable environment). In particular, we wish to understand when an individual with a dormancy trait can invade a resident population lacking this trait despite having a lower reproduction rate than the residents. To this end, we follow a stochastic individual-based approach employing birth-and-death processes, where dormancy is triggered by competitive pressure for resources. In the large-population limit, we identify a necessary and sufficient condition under which a complete invasion of mutants has a positive probability. Further, we explicitly determine the limiting probability of invasion and the asymptotic time to fixation of mutants in the case of a successful invasion. In the proofs, we observe the three classical phases of invasion dynamics in the guise of Coron et al. (2017, 2019). (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free