Bap55 mutants cause derepression of a PN-GAL4. (A) WT Mz19 anterodorsal neuroblast clones label PNs targeting to the VA1d and DC3 glomeruli. The DC3 glomerulus is difficult to visualize in confocal stacks. (B) WT Mz19 lateral neuroblast clones label a single class of PNs targeting to the DA1 glomerulus. (C) WT Mz19 never labels ventral PN neuroblast clones. No labeling is observed in the antennal lobe. (D) Bap55-/-Mz19 anterodorsal neuroblast clones exhibit ectopic labeling of PNs targeting many glomeruli in the anterior antennal lobe. (E) Bap55-/-Mz19 lateral neuroblast clones exhibit ectopic labeling of local interneurons, which target throughout the antennal lobe. (F) Bap55-/-Mz19 clones ectopically label ventral PNs, which are never labeled in WT, and that target to very few glomeruli in the antennal lobe. (G, H) WT Mz19 never labels a single anterodorsal PN when clones are generated just after larval hatching. (G1, G2) show no labeling in the antennal lobe. (H) shows no axon labeling in the lateral horn. (I, J) Bap55-/-Mz19 exhibits ectopic labeling of single anterodorsal PNs, which target to the anterodorsal glomerulus DA4l (I1), while avoiding the posterior glomerulus DL1 (I2). The axons form an L-shaped pattern in the lateral horn, with branches in the mushroom body calyx (J). Green marks mCD8-GFP-labeled PNs generated by MARCM and labeled using Mz19-GAL4. (G, I) show partial confocal stacks; (A-F, H, J) show full confocal stacks; magenta is the presynaptic marker nc82; symbols are as in Figure 2. Scale bars: 20 μm in (A) (for A-G, I) and (H) (for H, J).