Understanding chemical warfare in the nest of leafcutter ants

All plants and animals are associated with beneficial bacterial communities that we call their microbiomes. Despite recent advances in microbial community analysis however we have a very limited understanding of how a host assembles a beneficial microbiome or the benefits exchanged between the host and symbiotic bacteria.
We address these questions using South American leafcutter ants as a model system. Acromyrmex echinatior ants cut leaves from the rainforest and feed them to a symbiotic fungus that they grow as food. The fungal cultivar is the sole food source for their larvae and without it the colony will die. However, the ants are plagued by a co-evolved fungus called Escovopsis which parasitises the fungal cultivar and cause it, and the whole ant colony, to die. To combat Escovopsis the ants grow antibiotic-producing actinomycete bacteria on the outsides of their bodies. The bacteria make antibacterials that prevent other bacteria from growing on the ants and antifungals which the ants use as weed killers to kill the Escovopsis. This is a great model system because the microbiome is well characterised, external and experimentally tractable.
In this interdisciplinary project you will use cutting edge techniques, including dual RNA-seq, stable isotope probing and mass spectrometry to understand the positive and negative interactions that occur between the ants, their microbiome bacteria and the Escovopsis parasite and to determine which antibiotics the actinomycete bacteria are making to prevent other bacteria from invading their niche.