Gene-Environment Interplay on Oviposition Site Selection in Drosophila melanogaster

The underlying mechanisms of decision-making behaviour are poorly understood. Oviposition site selection (OSS) in the Drosophila melanogaster fruit fly provides a useful system for studying simple decision-making. OSS is influenced by both genetic and environmental variation. Variation of the foraging gene (for) is known to affect OSS. Given a choice of highand low-nutrient oviposition sites, groups of rovers (for) lay significantly more of their eggs on low-nutrient sites than sitters (for) and sitter mutants (for). I examined the roles of choice, female density, and for expression in gustatory neural circuitry in rover/sitter differences in OSS. I found a role of choice and female density in rover/sitter differences, and a role of for in response to glycerol, an indicator of yeast. However, driving for-mRNA expression in gustatory neurons using the GAL4/UAS system did not alter OSS. These findings suggest a central role of for in decision-making