Fruitless produces diverse neuronal sex differences by editing lineage-programmed chromatin landscapes

neurons from both sexes (i.e. with and without Fru protein) we determine the transcriptional mechanisms by which Fruitless produces cell-type specific regulatory effects. We demonstrate that Fruitless's actions are constrained by the chromatin landscape produced by cell lineage. Within lineage-specific landscapes, type-specific transcriptional dimorphisms arise from varying "Fru power" across cell types, which emerges as a combination of Fruitless dose, DNA binding domain isoforms, and the motif repertoire of individual enhancers. Together, these mechanisms allow a single factor to produce multifaceted transcriptional effects that subtly alter individual neuron types and produce sex-specific circuit functions.