Kith and kin in amoeba-bacteria cooperation

了解微生物之间的合作是至关重要的。病原微生物有时会以伤害我们的方式合作。组成我们肠道微生物群的细菌可以以对我们有益的方式合作。微生物既可以与本物种的成员合作，也可以与其他物种合作。这个项目将展示物种内部和物种之间的合作实际上是如何密切相关的。首先，这两个过程经常一起工作。微生物群体之间的合作需要它们与更大的宿主生物合作。本研究将通过使用一个简单易懂的模型系统来检验偏爱亲属如何影响与主人的合作。许多伯克氏菌寄生在变形虫宿主体内，产生有益和有害的影响。这项研究将展示细菌的合作能力，尤其是在近亲之间的合作能力，是如何影响宿主的生存和繁殖的。物种内和物种间合作的理论有相似之处。研究人员将为一个更统一的理论构建数学模型，该理论将允许对一种合作类型的见解应用于另一种合作类型。最后，这项研究将通过将微生物伴侣放在实验室中来测试这些理论，看看随着时间的推移，使用实验进化会发生什么变化。这项工作的结果将解释远远超出细菌-变形虫系统的微生物相互作用，对医学和农业具有潜在的见解。研究人员将开发主动学习模块，使学生能够操纵微生物相互作用的模型并看到结果。他们还将制作教育短片，广泛提供。合作既发生在物种内部，也发生在物种之间，但这两个领域一直是分开研究的。本研究将以三种方式连接这些研究传统，通过研究变形虫-细菌互惠关系中亲缘选择的重要性，通过开发形式上类似于亲缘选择模型的互惠关系的亲缘选择模型，并将这些模型应用于变形虫-细菌互惠关系。首先，研究人员将研究种内亲缘选择在种间共生，即变形虫-细菌原农业系统中的重要性。他们将调查细菌的亲缘关系，它们的亲缘识别，以及它们对宿主适应性的影响。其次，他们将对未被充分研究的物种选择方面进行建模，在这种选择中，合作者付出了直接的适应成本，但可以通过其他物种的间接利益得到补偿，模型采用了类似于遗传亲缘关系的回归系数。最后，研究人员将在不同的相互作用环境下进化参与者，以应用和测试模型。他们将决定直接选择的相对角色，由于合作伙伴的间接选择，以及他们的相互作用。该理论将有助于统一不同的思想流派，经验方法将可转移到许多其他系统。此外，研究人员将根据他们的研究主题开发教育模块，将涉及本科生和K12学生，并向公众发表演讲。他们还将通过学术成功策略方面的信息性文章促进教授的多样化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding cooperation among microbes is vital. Pathogenic microbes sometimes cooperate in ways that harm us. The bacteria comprising our gut microbiome can cooperate in ways that benefit us. Microbes can cooperate both with members of their own species and with other species. This project will show how within- and between species cooperation are actually closely related. First, the two processes often work together. Cooperation among microbial populations is required for them to cooperate with a larger host organism. This study will examine how favoring relatives affects cooperation with their host by using a simple, understandable model system. Many Burkholderia bacteria inhabit an amoeba host, conferring both helpful and harmful effects. The study will show how the ability of bacteria to cooperate, especially among relatives, affects host survival and reproduction. There are similarities between the theories of within- and between-species cooperation. The investigators will construct mathematical models for a more unified theory that will allow insights about one type of cooperation to be applied to the other type. Finally, this study will test these theories by putting the microbial partners together in the lab to see what changes occur over time using experimental evolution. The results of this work will explain microbial interactions far beyond this bacteria-amoeba system, with potential insights for medicine and agriculture. The investigators will develop active learning modules that allow students to manipulate models of microbial interactions and see the consequences. They will also produce short educational videos that will be widely available.Cooperation occurs both within and between species, but these two realms have been studied rather separately. This study will bridge these research traditions in three ways, by studying the importance of kin selection in an amoeba-bacteria mutualism, by developing kith selection models of mutualism that are formally similar to kin selection models, and by applying those models to an amoeba-bacteria mutualism. First, the investigators will study the importance of within-species kin selection in a between-species symbiosis, the amoeba-bacteria proto-farming system. They will investigate relatedness of the bacteria, their kin recognition, and the effects of these on host fitness. Second, they will model understudied aspects of kith selection in which cooperators pay a direct fitness cost but can be compensated by an indirect benefit from the other species, modeled by a regression coefficient that is formally similar to genetic relatedness. Finally, the investigators will evolve the participants under different interaction circumstances in the amoeba-bacteria mutualism to apply and test the models. They will determine the relative roles of direct selection, indirect selection due to partners, and their interaction. The theory will help unify disparate schools of thought and the empirical methods will be transferable to many other systems. Furthermore, the investigators will develop educational modules on the topic of their research, will involve undergraduates, and K12 students, and make presentations to the public. They also will facilitate diversification of the professoriate with informative pieces on academic success strategies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.