<i>Cis</i> -regulatory fragments from the <i>dissatisfaction</i> gene identify novel mating behavior neurons in female <i>Drosophila</i>

During Drosophila courtship, males chase and sing to females, while females perform abdominal behaviors to indicate their willingness to mate. The nerve cord circuits in females that produce their abdominal behaviors are poorly characterized. We recently identified an anatomically diverse population of abdominal interneurons called the dissatisfaction (dsf)- and doublesex-expressing abdominal ganglion (DDAG) neurons that influence several female mating behaviors. Here, we searched the dsf locus for cis-regulatory enhancer fragments that regulate its spatial expression in the adult and larval central nervous system. We found several enhancers, most located within 2 introns, that drove reporter expression in subsets of dsf-expressing neurons throughout the brain and nerve cord. Using one of these enhancers, we genetically isolated a single subtype of female-specific DDAG local interneurons. Optogenetic activation of these neurons triggered vaginal plate opening in both unmated and mated females, a behavior used by Drosophila females to signal receptivity to courting males. Our findings offer new reagents to target dsf-expressing cells and new insights into the neural substrates in Drosophila females that express their mating decisions during courtship.