Decoding sexual dimorphism of the sex-shared nervous system at single-neuron resolution

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Sex-specific behaviors are linked to neuronal differences, but the molecular basis at the single-neuron level is poorly understood.
• Understanding how genetic sex influences neural molecular architecture is crucial for deciphering behavioral dimorphism.

Purpose of the Study:

• To investigate the molecular differences between neurons in adult male and hermaphrodite C. elegans.
• To identify genes and regulatory mechanisms contributing to sex-specific neuronal wiring and behavior.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) was employed to profile the transcriptomes of sex-shared neurons.
• Comparative analysis of gene expression patterns between male and hermaphrodite C. elegans nervous systems.

Main Results:

• Widespread molecular dimorphism was observed across neuron types, including touch receptors.
• Neuropeptide and signaling genes showed significant sex-biased expression, especially in males.
• Neurotransmitter identities were largely conserved, suggesting modulatory roles in functional dimorphism.

Conclusions:

• Genetic sex profoundly impacts neuronal molecular composition, driving functional diversification of conserved circuits.
• Sex-biased gene expression correlates with synaptic connectivity biases, highlighting regulatory candidates for wiring.
• This molecular framework aids in understanding the neural basis of sex-specific behaviors.