Fig. 4. Or47a and Or47b axons show strong pathfinding defects and terminate in ectopic glomeruli in dock mutants. Antennal lobes, in which single Or47a or Or47b axons were labeled with mCD8::GFP using the MARCM technique, were stained with anti-CD8 (green) and nc82 mAb (red). See Materials and Methods for the genotypes. (A,B) In wild type, each Or47a axon can be seen to synapse on the ipsilateral DM3 and then send a collateral to the contralateral DM3. (C,D) In the dock mutant, Or47a axons branch normally. However, both axon branches are severely misrouted and arborize away from their normal target area. (E,F) Wild-type Or47b axons terminate on VA1lm and extend a collateral across the commissure to the corresponding glomerulus on the contralateral lobe. (G,H) In the dock mutant, some Or47b axons can be seen extending to dorsal brain regions (arrowhead), while others stop short of VA1lm. Broken outlines in all panels indicate the approximate positions of the glomerular targets. Scale bar: 25 µm.