Sex Differences in Sociability for Drosophilamelanogaster with Altered Gut Microbiomes.

In Drosophila melanogaster the gut microbiome has been shown to influence multiple behaviors, including aggressive social behavior. Here, we investigate the effect of the Drosophila microbiome on pro-social behavior. We predicted that reducing the microbiome would lead to a decrease in pro-social behavior in adult flies. After altering the flies' microbiomes, we observed that virgin male flies with reduced microbiomes were significantly less social than virgin male control flies (t=3.09, p=0.006). We did not observe this difference in virgin female flies (t=0.344, p=0.73), or mated flies of either sex (males: t=0.456, p=0.66; females: t=0.271, p=0.79). Our results suggest that the role of the Drosophila microbiome in pro-social behavior is dependent on both sex and previous social experience.