Insights into the mechanism of sexually dimorphic synaptic connectivity

In sexually reproducing species, males and females respond to environmental sensory and transform the input into sexually dimorphic traits. These dimorphisms are the basis for sex-biased phenotypes in many neurological diseases. Yet, complete understanding of the underlying mechanism is still missing. How does the sexual identity impose molecular changes to individual neurons and circuits? What are the sex-specific synaptic changes that occur during development in these circuits? We have recently shown that synaptic elimination plays a central role in generating sexually dimorphic circuits in the nematode C. elegans - synapses between sex-shared neurons are removed dimorphically during development to accommodate for sex-specific behaviors. We will demonstrate the involvement of the ubiquitin-proteasome system (UPS) in sex-specific synapse pruning, and discuss how the sexual identity intersects with signaling pathways to confer spatial and temporal specificity for synapse elimination.