Figure 2

Mushroom body neurons are divided into molecularly distinct compartments. Mushroom body neurons expressing tagged markers were generated by crossing flies containing mushroom body Gal4 drivers with flies carrying UAS-controlled markers. The 201Y Gal4 was used in all panels except L10-YFP and homer-GFP, for which the OK107 Gal4 was used. 201Y drives expression in a large subset of mushroom body neurons [54, 55], and OK107 drives expression in all mushroom body neurons [11] as well as the optic lobe. Brains were dissected from third instar larvae, fixed and analyzed by confocal microscopy. All panels represent confocal projections through the entire mushroom body, except homer-GFP, which shows the cell bodies, dendrites and proximal axons, with distal axons in the inset. Low expression levels of n-syb-YFP expression were generated by using a 2XUAS vector, and low levels of homer-GFP were generated by raising larvae at 18°C. Arrow points to region of proximal axon in which Apc-2 GFP was localized. Scale bar at lower right is 20 μm.