Fig. 3. Atrophy of the dendritic arborization of the lateral neurons in the absence of the BN. (A-F) Whole-mounts of third instar larval CNS; LNs are stained with GFP (green) and the visual system with anti-chaoptin (red). (A,B) Visual system (A) and LNs (B) in a w; UAS-gfp/+; gal1118/+ control CNS. (C) Apparently normal visual system in a w UAS-hid UAS-rpr/w; UAS-gfp/+; gal1118/+ CNS (as observed in 10 out of 10 brains). (D) BN-depleted visual system and LNs without dendritic arborization in a w; GMR-hid/UAS-gfp; gal1118/+ CNS. Although the BN was always undetectable in these third instar larval brains, the developing adult photoreceptors were present. They only degenerated during pupal life (data not shown), presumably when the apoptotic pathways were fully activated by HID expression. (E) Absence of visual system, and LNs without any detectable dendritic arborization in a w; UAS-gfp/+; gl^60J gal1118/ gl^60J CNS. (F) Visual system without adult photoreceptors and LNs with their dendritic arborization in a w; eya² UAS-gfp/ eya²; gal1118/+ mutant. (G,H) Whole-mounts of third instar larval CNS. LNs are stained with anti-PDF. (G) LNs without dendritic tree in a somda mutant. Broken line indicates the limit between different focal planes. (H) Wild-type LNs. A dendritic arborization was observed in only 9% of somda brain hemispheres (n=34), versus 92% of controls (n=13). APP, adult photoreceptors projections; BN, Bolwig nerve; DA, dendritic arborization of LNs; DP, dorsal projections of LNs; LNs, lateral neurons. Scale bar: 10 µm.