decepentaplegic directs wiring of female-differentiated fruitless sex peptide response-inducing neurons

Female reproductive success requires coordinated behavioural responses following mating. In Drosophila melanogaster , these responses include reduced receptivity to further mating and increased oviposition, which are triggered by the male-derived sex-peptide (SP). Although the neural pathways controlling these behaviours have been partially characterized, the developmental mechanisms that establish and maintain these circuits remain poorly understood. Using a genetic approach, we identified an EMS-induced mutant that retains eggs and fails to reduce receptivity following SP exposure. We mapped this mutation to the dpp locus. Dpp acts within SP response inducing neurons (SPRINz) fru11/12 ∩ dsx and fru11/12 ∩ FD6 as downregulating dpp in subsets of sex-peptide target neurons disrupts receptivity. Here, dpp is required for correct neuronal wiring in dpp ^HB3 mutants. Moreover, female sexual differentiation trough the sex determination gene tra is required in SPRINz to display post-mating behaviours. Together, these findings suggest a new role for dpp in specifying neuronal connectivity in the context of sexual differentiation by the Drosophila canonical sex determination pathway to implement neuronal wiring for post-mating behaviours.