Investigation of Drosophila fruitless neurons that express Dpr/DIP cell adhesion molecules
Savannah G Brovero, Julia C Fortier, Hongru Hu, Pamela C Lovejoy, Nicole R Newell, Colleen M Palmateer, Ruei-Ying Tzeng, Pei-Tseng Lee, Kai Zinn, Michelle N Arbeitman
Abstract
Drosophila reproductive behaviors are directed by fruitless neurons. A reanalysis of genomic studies shows that genes encoding dpr and DIP immunoglobulin superfamily (IgSF) members are expressed in fru P1 neurons. We find that each fru P1 and dpr/DIP ( fru P1 ∩ dpr/DIP ) overlapping expression pattern is similar in both sexes, but there are dimorphisms in neuronal morphology and cell number. Behavioral studies of fru P1 ∩ dpr/DIP perturbation genotypes indicate that the mushroom body functions together with the lateral protocerebral complex to direct courtship behavior. A single-cell RNA-seq analysis of fru P1 neurons shows that many DIPs have high expression in a small set of neurons, whereas the dprs are often expressed in a larger set of neurons at intermediate levels, with a myriad of dpr/DIP expression combinations. Functionally, we find that perturbations of sex hierarchy genes and of DIP-ε change the sex-specific morphologies of fru P1 ∩ DIP-α neurons.