Immunofluorescent labeling of neural stem cells in the Drosophila optic lobe

The Drosophila visual system is an excellent model system to study the switch from proliferating to differentiating neural stem cells. In the developing larval optic lobe, symmetrically dividing neuroepithelial cells transform to asymmetrically dividing neuroblasts in a highly ordered and sequential manner. This chapter presents a protocol to visualize neural stem cell types in the Drosophila optic lobe by fluorescence confocal microscopy. A main focus is given on how to dissect, fix, immunolabel, and mount brains to reveal cellular morphology during early larval brain development.