Collaborative Research: Mapping interactions mediated by secondary metabolites in a fungus-growing ant microbiome

大多数微生物产生小分子次级代谢物作为信号和/或抗生素，控制物种之间的相互作用。尽管这些分子具有巨大的医学意义，但它们的自然多样性和功能仍然不为人所知。这阻碍了对微生物群落如何维持关键生态系统功能（如健康的宿主-微生物关系）的充分理解。为了进一步了解这些系统，该项目将基于环境样品中特定微生物和次生代谢物的共存，生成微生物相互作用及其相关次生代谢物的网络。工作将在真菌生长蚂蚁Trachymyrmex septentrionalis上进行，作为这些研究的实验模型，分析在美国东部收集的蚁群中由次级代谢物介导的宿主-微生物相互作用。通过与新设计的网络资源相连接的公共展示，还将利用七氏绦虫的共生关系广泛地展示动物与微生物相互作用的基础知识。此外，博士后、研究生和本科生研究人员将接受微生物学和化学生态学方面的培训，包括代表性不足的群体的成员。因此，该项目将广泛推进对次生代谢物的多样性和自然功能及其对宿主-微生物相互作用的影响的理解。几乎所有的微生物都会产生次生代谢物。这些分子在共生体中特别常见，它们介导宿主与微生物的相互作用。这种相互作用通常使用低通量方法进行研究，该方法将次生代谢物产生生物从其自然群落中去除。因此，这些实验不足以确定原位次生代谢物的多样性，也不能明确地将特定分子与它们自然介导的生态相互作用联系起来。为了克服这些局限性，本项目将开发一种方法，通过鉴定相互作用分类群和介导这些相互作用的次级代谢物之间的共变异模式，全面鉴定由次生代谢物介导的种间相互作用，以真菌生长蚂蚁Trachymyrmex septentrionalis为实验模型。在这种方法中，相互作用的分类群将与彼此以及介导这种相互作用的代谢物共同发生。相反，拮抗相互作用的分类群很少共存，介导这种拮抗相互作用的代谢物将与产生分类群共存，而不是与目标分类群共存。原位相互作用将用实验室蚁群微生物培养进行概括。各级研究人员将接受这些分子和化学生态学方法的培训，并将开发博物馆和在线资源，向更广泛的公众传播结果。总之，该项目将提供一种方法学方法来绘制微生物群落中次生代谢物介导的相互作用，并确定这些分子的原位功能。

Most microbes produce small molecule secondary metabolites as signals and/or antibiotics that control interactions between species. Despite their immense medical importance, the natural diversity and function of these molecules remains obscure. This prevents a full understanding of how microbial communities maintain critical ecosystem functions such as healthy host-microbe relationships. To further understand these systems, this project will generate networks of microbial interactions and their associated secondary metabolites based on the co-occurrence of particular microbes and secondary metabolites in environmental samples. Work will be conducted on the fungus-growing ant Trachymyrmex septentrionalis as an experimental model for these studies, profiling host-microbe interactions that are mediated by secondary metabolites within ant colonies collected throughout the Eastern USA. The T. septentrionalis symbiosis will also be utilized to broadly demonstrate the basics of animal-microbe interactions via a public display that will be linked to newly designed web resources. In addition, postdoctoral, graduate, and undergraduate researchers will be trained in microbiology and chemical ecology, including members of underrepresented groups. This project will therefore broadly advance understanding of the diversity and natural function of secondary metabolites and their impacts of host-microbe interactions.Nearly all microbes produce secondary metabolites. These molecules are particularly common in symbioses, where they mediate host-microbe interactions. Such interactions are typically studied using low-throughput approaches that remove secondary metabolite-producing organisms from their natural communities. These experiments are therefore insufficient to determine in situ secondary metabolite diversity, and cannot unambiguously link specific molecules to the ecological interactions that they naturally mediate. To overcome these limitations, this project will develop an approach to comprehensively identify interspecific interactions mediated by secondary metabolites by identifying patterns of co-variation between interacting taxa and the secondary metabolites that mediate these interactions, using the fungus-growing ant Trachymyrmex septentrionalis as an experimental model. In this approach, taxa that interact mutualistically will co-occur with both each other and the metabolite that mediates this mutualistic interaction. Reciprocally, taxa that interact antagonistically will rarely co-occur, and the metabolite that mediates this antagonistic interaction will co-occur with the producing taxon but not the target taxon. In situ interactions will be recapitulated using laboratory ant colonies microbial cultures. Researchers at various levels will be trained in these molecular and chemical ecology methods and museum and online resources to disseminate results to the broader public will be developed. Together, this project will provide a methodological approach to map interactions mediated by secondary metabolites in microbial communities and identify the in situ functions of such molecules.