IRCEB: Evolutionary Ecology of the Attine Ant-Microbe Mutualism: Experimental and Molecular Approaches to Understanding Symbiosis and Coevolution

蚂蚁农业，以种植真菌的蚂蚁与其真菌品种之间的共生为例，作为理解形成高度整合共生的一般生态和共同进化机制的模型系统进行了深入研究。蚂蚁农业共生关系包括(1)蚁农、(2)真菌品种、(3)寄生于蚂蚁花园的真菌“杂草”、(4)控制花园寄生虫并在蚂蚁身上培养的产生抗生素的细菌之间的互惠和寄生相互作用。该项目专门探讨了抗真菌-细菌共生的生态复杂性，并通过测试多个生态和进化水平的假设来阐明其5000万年的共同进化历史，包括：(1)蚁群内的局部生态水平；(2)人口和社区层面；(3)生物地理水平；系统发育层面包括(4)共同进化过程与历史生态学；(5)共生介导的物种形成；(6)共生生命史对进化变化速率的影响。因为共生是生命史上一个反复出现的主题，这项研究有望对推动生物复杂性和多样性的广泛机制产生一般性的见解。在某些情况下，这些见解可能会影响与人类福利直接相关的问题，包括抗生素耐药性的演变和可持续农业的实践。

Ant agriculture, exemplified by the symbiosis between fungus-growing (attine) ants and their fungal cultivars, is intensively studied as a model system for understanding the general ecological and coevolutionary mechanisms that shape highly integrated symbioses. The attine ant agricultural symbiosis encompasses both mutualistic and parasitic interactions between (1) ant farmers, (2) fungal cultivars, (3) parasitic fungal "weeds" that infest ant gardens, and (4) antibiotic-producing bacteria that control the garden parasites and are cultured on the bodies of ants. This project specifically explores the ecological complexity of the attine ant-fungus-bacterium symbiosis and elucidates its 50-million-year coevolutionary history by testing hypotheses posed at multiple ecological and evolutionary levels, including: (1) the local ecological level within ant colonies; (2) the population and community levels; (3) the biogeographic level; and the phylogenetic level, including (4) coevolutionary processes and historical ecology; (5) symbiont-mediated speciation; and (6) the effects of symbiotic life histories on rates of evolutionary change. Because symbiosis is a major recurring theme in the history of life, this research is expected to generate general insights into the broad mechanisms that drive biological complexity and diversity. Such insights could in some cases impact issues directly relevant to human welfare, including the evolution of antibiotic resistance and the practice of sustainable agriculture.