decepentaplegic directs the 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 {cap} dsx and fru11/12 {cap} FD6 as downregulating dpp in subsets of sex-peptide target neurons disrupts receptivity. Here, dpp is required for correct neuronal wiring in dppHB3 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.