Single-cell transcriptome profiles of Drosophila fruitless-expressing neurons from both sexes

Abstract

Drosophila melanogaster reproductive behaviors are orchestrated by fruitless neurons. We performed single-cell RNA-sequencing on fru P1 pupal neurons. Uniform Manifold Approximation and Projection (UMAP) clustering generates an atlas containing 113 clusters. While the male and female neurons overlap in UMAP space, more than half the UMAP clusters have sex-differences in neuron number, and nearly all clusters display sex-differential expression. Based on an examination of enriched marker genes, we annotate clusters as circadian clock neurons, mushroom body Kenyon cell neurons, neurotransmitter- and/or neuropeptide-producing, and those that express doublesex. Enriched marker gene analyses also shows that genes that encode members of the immunoglobulin superfamily of cell adhesion molecules, transcription factors, neuropeptides, neuropeptide receptors, and Wnts have unique patterns of enriched expression across the clusters. In vivo spatial gene-expression links to the UMAP clusters are provided. A functional analysis of fru P1 circadian neurons shows they have dimorphic roles in sleep/activity and period length. Given that most clusters are comprised of male and female neurons indicates that the sexes have fru P1 neurons with common gene expression programs. Sex-specific expression is overlaid on this program, to build the potential for vastly different sex-specific behaviors.