There is growing theoretical evidence that spatial structure can affect the ecological and evolutionary outcomes of host-parasite interactions. Locally restricted interactions have been shown in particular to affect host resistance and tolerance. In this study we investigate the evolution of several types of host disease resistance strategies, alone or in combination, in spatially structured populations. We construct a spatially explicit, individual-based stochastic model where hosts and parasites interact with each other in a spatial lattice, and interactions are restricted to a given neighbourhood of varying size. We investigate several host resistance strategies, including constitutive (expressed in all resistant hosts), induced (expressed only upon infection), and combinations thereof. We show that a costly constitutive resistance cannot reach fixation, whereas an inducible resistance strategy may become fixed in the population if the cost remains low, particularly if it impacts host recovery. We also demonstrate that mixed strategies can be maintained in the host population, and that a higher investment in a recovery-boosting inducible resistance allows for a higher investment in a constitutive response. Our simulations reveal that the spatial structure of the population impacts the selection for resistance in a complex fashion. While single strategies of resistance are generally favoured in less structured populations, mixed strategies can sometimes prevail only in highly structured environments, e.g. when combining constitutive and transmission-blocking induced responses Overall these results shed new light on the dynamics of disease resistance in a spatially-structured host-pathogen system, and advance our theoretical understanding of the evolutionary dynamics of disease resistance, a necessary step to elaborate more efficient and sustainable strategies for disease management.

中文翻译：

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宿主对空间结构性种群中病原体的抗性策略：基于代理的评估。

越来越多的理论证据表明空间结构可以影响宿主-寄生虫相互作用的生态和进化结果。已显示局部受限的相互作用特别影响宿主的抗性和耐受性。在这项研究中，我们调查了空间结构性种群中几种类型的宿主抗病性策略（单独或组合）的演变。我们构建了一个空间明确的，基于个体的随机模型，在该模型中，宿主和寄生虫在空间格子中相互影响，并且相互作用被限制在给定大小不一的邻域中。我们研究了几种宿主抗性策略，包括组成型（在所有抗性宿主中均表达），诱导（仅在感染时表达）及其组合。我们表明，昂贵的本构抗性无法达到固定，而如果成本仍然很低，特别是如果它影响宿主的恢复，则诱导性抗性策略可能在人群中变得固定。我们还证明，可以在寄主群体中维持混合策略，并且在促进恢复的诱导抗性上进行更高的投资可以在本构反应上进行更高的投资。我们的模拟表明，种群的空间结构以一种复杂的方式影响着抗性的选择。虽然结构化程度较低的人群通常倾向于采用单一的抗药性策略，但有时混合策略有时只能在高度结构化的环境中盛行