OPUS: CRS: Synthesizing microbial ecology of fungus-growing ants

What are the rules to engineer microbiomes to improve health of animals and plants? What organisms use microbiome engineering to improve their own health? Do these organisms use specific mechanisms to assemble beneficial microbes into their microbiomes? Addressing these questions will elucidate general principles of microbiome engineering, with implications for medicine and agriculture. The proposed work will synthesize research on one group of organisms that have practiced microbiome engineering for millions of years, the fungus-growing insects, specifically fungus-growing ants. Fungus-growing insects are farmers. They cultivate gardens of fungal food embedded in complex communities of beneficial microbes that serve nutritive and health functions, but can also include microbial pathogens. Research during the last three decades vastly increased genomic, microbial, physiological, and biochemical understanding of such insect-microbe interactions. There exists therefore now an interest in a comparative synthesis of these diverse host-microbiome associations and the underlying rules of microbiome engineering.<br/><br/>The proposed work will generate two syntheses to elucidate general principles of microbiome assembly and microbiome interactions with the host. The first synthesis will summarize recent microbial, genomic, and biochemical insights on fungus-growing insects to (i) generate an integrative understanding of ecological and evolutionary processes shaping such complex mutualisms; (ii) elucidate unresolved controversies; (iii) evaluate alternate hypotheses underlying these controversies; (iv) outline experimental work to test these hypotheses; and thus (v) identify promising novel research directions. The second synthesis will summarize the biology of fungus-growing ants occurring in the US to enable researchers to address the promising research directions that emerge from the first synthesis. The second synthesis will also integrate 25 years of unpublished observations and photography by the collaborating investigators on the fungus-growing ants of the USA. The second synthesis will therefore enable US researchers to take advantage of their local biodiversity and develop local study systems. The project will also generate visual media on all species of fungus-growing ants in the US and disseminate commons-use images to the public.<br/><br/>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.