Behavioral Impacts of the Gut Microbiome on Drosophila melanogaster

Recent studies indicate alterations in the gut microbiome impact behavior including increasing aggressive behavior. The gut of an organism is home to a complex community of bacteria, fungi and viruses that collectively make up the gut microbiome. The prevailing hypothesis is that changes in the microbiome are communicated to the brain and subsequently impact behavior. In the Certel lab, we are identifying factors that regulate aggressive behavior and have been specifically examining the role of octopamine using the model system Drosophila. Octopamine (OA) is a neurotransmitter and neuromodulator that is required to promote aggression. Males without OA exhibit decreased levels of aggression and increased levels of inter-male courtship. Here we ask how changes in the gut microbiome impact male aggressive behavior and how is OA involved? These questions are relevant as we recently determined OA neurons located in the brain also innervate the gut. We generated germfree males and our initial results suggest germfree males fight longer and at higher levels than control males. I will present additional results quantifying the aggression of germfree, OA null mutants, and appropriate controls. Our results describe the impact of the microbiome on animal behavior which may be broadly conserved