Localization of bacterial communities within gut compartments across Cephalotes turtle ants

Microbial communities within the animal digestive tract often play an important function for their hosts. The composition of gut bacteria throughout many eukaryotes can be structured by host diet, vertical bacterial transmission, and variation within the digestive tract. In several ant taxa, recent findings have demonstrated that nitrogen provisioning by symbiotic bacteria makes up for deficiencies in herbivorous diets. Using 16S rRNA amplicon sequencing and qPCR, this study examined bacterial communities at a fine scale across one such taxon, the turtle ant genus Cephalotes.  We analyzed bacterial gut compartment variation to understand how bacterial diversity is structured across the digestive tract, potentially allowing for specific beneficial functions to the host. In addition, we aimed to understand if caste differentiation or host relatedness influences the gut bacterial communities of Cephalotes ants. These findings are noteworthy since we found that gut communities vary strongly across Cephalotes gut compartments in ways that transcend both caste and host phylogeny. Despite this, caste and host phylogeny both have detectable effects. Specific gut compartments may be structuring and altering their microbial community at a fine-scale, possibly due to the varying function of each gut compartment for digestion.