Single-Nucleus Neuronal Transcriptional Profiling of Male C. elegans Uncovers Regulators of Sex-Specific and Sex-Shared Behaviors

Sexual differentiation of the nervous system causes differences in neuroanatomy, synaptic connectivity, and physiology. These sexually-dimorphic phenotypes ultimately translate into profound behavioral differences. C. elegans’ two sexes, XO males and XX hermaphrodites, demonstrate differences in neurobiology and behavior. However, the neuron class and sex-specific transcriptomic differences, particularly at the single-neuron level, that cause such phenotypic divergence remains understudied. Here, using single-nucleus RNA sequencing, we assessed and compared adult male and hermaphrodite C. elegans neuronal transcriptomes, identifying sex-specific neurons, including previously-unannotated male neurons. Sex-shared neurons displayed large expression differences, with some neuron classes clustering as distinct neurons between the sexes. Males express ∼100 male-specific GPCRs, largely limited to a subset of neurons. We identified the most highly-divergent neurons between the sexes, and functionally characterized a sex-shared target, vhp-1, in male-specific pheromone chemotaxis. Our data provide a resource for discovering nervous-system-wide sex transcriptomic differences and the molecular basis of sex-specific behaviors.