The origin of queen ant and the nest strata shape the assembly of the bacterial community associated with the fungus garden of Atta mexicana (Hymenoptera: Formicidae)

Many leaf-cutter ant species in the Attini tribe have evolved the ability to cultivate fungi for food, allowing them to become ecologically important herbivores and forest pests throughout the Neotropics. While the primary fungal gardens of these insects have been extensively researched for decades, their bacterial microbiota remains relatively underexplored, which is particularly true for Atta mexicana, a species distributed from Central to North America. In this work, we surveyed the assembly of the bacterial microbiota associated with the fungus garden of this species under controlled conditions, using high-throughput sequencing of the bacterial 16S ribosomal DNA gene. By doing so, we found differences in the bacterial community assembly associated to the origin of the founder queen ant and the nest level of the fungus garden, suggesting complex ongoing ecological succession processes, which we propose are driven by the spatial specialization along the fungus garden. This functional specialization could explain the differences we observed while also providing many ideas for future work.