Developmental and Behavioral Effects of Altered Microbiome in Drosophila melanogaster Using Antibiotics and Antifungal Treatments

Abstract

Changes to the microbiome have been shown to affect mating behavior in Drosophila melanogaster fruit flies. Here, we aimed to determine if different shifts in microbiomes, caused by consumption of various antibiotics, would differentially affect development and a simple behavioral response of fruit flies. Flies were reared with either sulfaquinoxaline, tetracycline, the anti-fungal drug ketoconazole, or no antibiotics for one generation to determine effects of the drugs on development, size and viability. Fewer adults developed when flies were reared with tetracycline, and fewer pupae formed when flies consumed ketoconazole. However, pupal size and adult mass were not affected by antibiotic consumption. To help determine if potential effects on behavior were caused to by changes in the maternally-transmitted microbial flora, as opposed to consumption of the antibiotics, adults that developed from each of the four groups founded a second generation in media without antibiotics. Once adults, these offspring were starved overnight and placed in the middle of a chamber with sucrose-supplemented agar at one end and agar alone at the other end. Control flies showed no preference for any area of the chamber. Flies whose parents were Ketoconazole- and Sulfaquinoxaline-reared preferred either the middle or the sucrose end of the chamber, while Tetracycline-reared descendants preferred the sucrose end. Future studies can test these differential preferences across larger populations of flies, different strains of flies, and in responses to other kinds of stimuli. However, this data suggests that differences in maternally-transmitted microbiomes could affect simple behavioral responses in fruit flies.