Cell-type-specific genetic tools for the Drosophila central complex and their use to investigate neuropeptide expression and sleep regulation.

The central complex (CX) plays a key role in many higher order functions of the insect brain including navigation and activity regulation. Genetic tools for manipulating individual cell types, and knowledge of what neurotransmitters and neuromodulators they express, will be required to gain detailed mechanistic understanding of how these functions are executed. We have generated and characterized a large collection of split-GAL4 driver lines that express in individual or small subsets of cell types in the Drosophila CX. We survey neuropeptide expression in the central brain using fluorescent in situ hybridization and show that several CX cell types express multiple neuropeptides. We use our driver lines to identify CX cell types whose activation affects sleep, and identified other central brain cell types that link the circadian clock to the CX. The well characterized genetic tools and information on neuropeptide expression we provide should enhance studies of the CX. Cell-type-specific drivers were used to identify specific cell types in the Drosophlia central complex, and these cells were isolated and RNA-Seq libraries were generated from them to determine the expression of neuropeptides and neurotransmitters.