Microbial evolution along the parasitism-mutualism continuum

动物和植物宿主由有害（寄生）和有益（互利）物种组成的不同微生物群落。然而，这些角色并不固定，可能取决于其他物种的存在。微生物沿着寄生和互利共生之间的连续体存在，但我们还不知道是什么驱使一些微生物成为寄生微生物，而另一些则成为互利共生微生物。最重要的是，我们不知道微生物在宿主体内的相互作用是如何联合收割机与宿主之间的传播结合起来的，从而推动选择沿着寄生-互惠连续体进行。我的研究计划的首要长期目标是开发和测试新的理论，以了解微生物如何以及为什么进化为寄生或互利共生。在接下来的五年里，我的团队将致力于三个短期目标：（1）从理论上确定宿主内和宿主间的过程如何驱动微生物中寄生和互利特性的进化;（2）对微生物的共同进化如何改变组分和群落水平的寄生和互利进行理论预测;以及（3）预测宿主内特定微生物群落的进化，并与实验室科学家合作使用已建立的进化实验来测试这些预测。 我们将开发数学模型，捕捉微生物跨尺度（内和宿主之间）的相互作用，并分析微生物性状，如毒力，传播性和宿主保护（共同）演变。这种方法将使我们能够描绘内和主机之间的规模选择寄生和互惠性状的影响。然后，我们将通过与实验室科学家合作，在微观蠕虫中实验性地进化细菌来测试我们的建模预测。我们的研究是理解宿主-微生物进化生态学的关键，为进化生物学家提供了新的理论框架和可检验的预测。了解微生物进化沿着寄生-互利共生连续体也对未来治疗传染病的疗法具有重要意义。例如，已知来自健康人类供体的微生物群落的移植是对某些抗微生物剂抗性感染的有效治疗。随着对微生物如何在群落中（共同）进化的基本过程的重要见解，我们将更好地安全和有目的地操纵我们体内的这些群落，为各种传染病创造新的治疗选择。

Animals and plants host diverse microbial communities consisting of both harmful (parasitic) and beneficial (mutualistic) species. However, these roles are not fixed and may depend on which other species are present. Microbes exist along a continuum between parasitism and mutualism, but we do not yet know what drives some to be parasitic and others to be mutualistic. Crucially, we do not know how microbial interactions within a host combine with transmission between hosts to drive selection along the parasitism-mutualism continuum. The overarching long-term goal of my research program is to develop and test novel theory to understand how and why microbes evolve to be parasitic or mutualistic. Over the next five years, my team will address three short-term objectives: (1) theoretically determine how within- and between-host processes drive the evolution of parasitic and mutualistic traits in a microbe; (2) develop theoretical predictions for how microbial coevolution shifts constituent- and community-level parasitism and mutualism; and (3) predict evolution in specific microbial communities inside a host and test these predictions in collaboration with lab scientists using established evolution experiments. We will develop mathematical models that capture microbial interactions across scales (within- and between-host) and analyse how microbial traits such as virulence, transmissibility, and host protection (co-)evolve. This approach will allow us to delineate the impact of the within- and between-host scales on selection for parasitic and mutualistic traits. Then, we will test our modelling predictions by working with lab scientists to experimentally evolve bacteria in microscopic worms. Our research is key to understanding host-microbe evolutionary ecology, providing evolutionary biologists with novel theoretical frameworks and testable predictions. Understanding microbial evolution along the parasitism-mutualism continuum also has important implications for future therapeutics to treat infectious diseases. For example, transplantation of microbial communities from healthy human donors is known to be an effective treatment for certain antimicrobial resistant infections. With crucial insights into the fundamental processes of how microbes (co)evolve in communities, we will be better placed to manipulate these communities inside our bodies safely and purposefully to create new therapeutic options for a variety of infectious diseases.