Diet-induced mating preference in Drosophila

Diet-induced mating preference was initially observed by Dodd (1). Subsequently, we reported that diet-induced mating preference occurred in Drosophila melanogaster. Treatment of the flies with antibiotics abolished the mating preference, suggesting that fly-associated commensal bacteria were responsible for the phenomenon (2). The hypothesis was confirmed when it was shown that colonizing antibiotic-treated flies with Lactobacillus plantarum reestablished mating preference in multiple-choice mating assays with CMY (0.65% agar, 7.6% cornmeal, 7.6% molasses, 5% inactivated brewer's yeast, 0.1% methyl-4-hydroxybenzoate, 0.76% ethanol, and 0.4% propionic acid) flies. Furthermore, analytical studies indicated that the flies grown on different media had distinct levels of cuticular hydrocarbon sex pheromones. The difference in their levels was reduced when the flies were treated with antibiotics.