Sex-specific neurons play pivotal roles in regulating sexually dimorphic behaviors. In insects, the sex determination gene doublesex (dsx) establishes major sexual dimorphism of the nervous system, in which male-specific dsxM promotes neuronal development, while female-specific dsxF inhibits neuronal development by promoting neuronal apoptosis. In this study, we find that dsx regulates the number of dsx-expressing central neurons in Drosophila in cell-specific manners. Although dsxM overall promotes an increase in the number of dsx neurons, it inhibits the emergence of specific pC1 neurons. dsxF reduces the number of different pC1/pC2 subtypes, but promotes the formation of pC1d. We also find that dsxM and dsxF barely affect the number of some pC2 neurons. Changes in the number of pC1/pC2 neurons alter their roles in regulating different behaviors, including courtship, aggression, and locomotion. Our results illustrate the multifaceted functions of dsx in sexually dimorphic neuronal development and behaviors.

doublesex

Sexual dimorphism

Neuronal development

Courtship

Aggression

Locomotion

Drosophila

© 2025 The Authors. Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Limited and Science Pressé