Developmental remodeling repurposes larval neurons for sexual behaviors in adultDrosophila

Abstract

SUMMARYMost larval neurons inDrosophilaare repurposed during metamorphosis for functions in adult life, but their contribution to the neural circuits for sexually dimorphic behaviors is unknown. Here, we identify two interneurons in the nerve cord of adultDrosophilafemales that control ovipositor extrusion, a courtship rejection behavior performed by mated females. We show that these two neurons are present in the nerve cord of larvae as mature, sexually monomorphic interneurons. During pupal development, they acquire the expression of the sexual differentiation gene,doublesex, undergodoublesex-dependent programmed cell death in males, and are remodeled in females for functions in female mating behavior. Our results demonstrate that the neural circuits for courtship inDrosophilaare built in part using neurons that are sexually reprogrammed from former sex-shared activities in larval life.