论文标题
细菌种群的休眠和转移的相互作用：入侵，固定和共存状态
The interplay of dormancy and transfer in bacterial populations: Invasion, fixation and coexistence regimes
论文作者
论文摘要
我们研究了微生物种群动力学的两个基本机制与称为休眠和水平基因转移的相互作用。相应的特征是有许多伪造的，在微生物群落中无处不在，以重要的方式影响了它们的动态。最近，他们分别（分别）进入了基于随机的个体建模的重点（Billiard等，2016，2018; Champagnat，Méléard和Tran，2021; Blath andTóbiás2020）。在这里，我们在统一模型中检查了它们的综合效果。确实，我们考虑了两个子人群的（理想化的）场景，分别携带“性状1”和“特质2”，其中特质1个人能够（在竞争压力下）转变为休眠状态，并且特质2个人能够以水平基因转移，将特质1个个体变成特质2个个人，并以率根据个人的频率，将特质1个个人变成特质。在大种群的限制中，我们研究了一个人（一个“突变”）到达居住在平衡状态的特质J居民人口的命运，价格为$ i，j = 1,2，i \ neq j $。在所有居民人群分别拟合并且突变人群的初始行为的所有情况下，我们提供了对入侵动态的完整分析。我们确定了参数制度，用于入侵和固定新特征，两个特征的稳定共存以及“创始人控制”（最初的居民始终占主导地位，无论其特征如何）。最引人注目的结果是，即使某些特征2（以特质为代价1的转移受益）在某些情况下也会发生稳定的共存，而仅仅是单独使用时不适合。在创始人控制的情况下，极限动态系统具有不稳定的共存平衡。在所有情况下，我们都会观察到Champagnat（2006）的入侵动态的古典（最多3）阶段。
We investigate the interplay between two fundamental mechanisms of microbial population dynamics and evolution called dormancy and horizontal gene transfer. The corresponding traits come in many guises and are ubiquitous in microbial communities, affecting their dynamics in important ways. Recently, they have each moved (separately) into the focus of stochastic individual-based modelling (Billiard et al. 2016, 2018; Champagnat, Méléard and Tran, 2021; Blath and Tóbiás 2020). Here, we examine their combined effects in a unified model. Indeed, we consider the (idealized) scenario of two sub-populations, respectively carrying 'trait 1' and 'trait 2', where trait 1 individuals are able to switch (under competitive pressure) into a dormant state, and trait 2 individuals are able to execute horizontal gene transfer, turning trait 1 individuals into trait 2 ones, at a rate depending on the frequency of individuals. In the large-population limit, we examine the fate of a single trait i individual (a 'mutant') arriving in a trait j resident population living in equilibrium, for $i,j=1,2,i \neq j$. We provide a complete analysis of the invasion dynamics in all cases where the resident population is individually fit and the initial behaviour of the mutant population is non-critical. We identify parameter regimes for the invasion and fixation of the new trait, stable coexistence of the two traits, and 'founder control' (where the initial resident always dominates, irrespective of its trait). The most striking result is that stable coexistence occurs in certain scenarios even if trait 2 (which benefits from transfer at the cost of trait 1) would be unfit when being merely on its own. In the case of founder control, the limiting dynamical system has an unstable coexistence equilibrium. In all cases, we observe the classical (up to 3) phases of invasion dynamics à la Champagnat (2006).
