Fig. S3

Lamination of Tectal Dendrites Is Disrupted in drg^s510 Mutants and Radial Glia Appear Morphologically normal in box Mutants, Related to Figure 5(A–C) TEM photographs of the basement membrane of WT (A) and drg^s510 (B, C) tectum at 5 dpf. The arrow in A points at the lamina densa in WT. Yellow arrowheads in B and C point at the putative lamina densa in drg^s510 tectum(B, C). Instead of a smooth lamina densa, which contains type IV Collagen, two thin electron-dense layers are present in drg^s510. Red stars indicate neurites, probably axonal profiles, aberrantly projecting into the ECM near the surface. Scale bar is 0.5 µm.(D and E) Single optical sections of Dlx5/6:GFP transgenic fish at 6 dpf. The WT pattern (D) shows six laminae. In drg^s510 (F), these laminae are present but more diffuse, and the superficial-most terminations are disrupted.(F–I) Projections of radial glia in Gal4s1082t crossed to UAS:Kaede in WT (F, H) and box^{tm70 g} (G, I) at 3 dpf (F, G) and 5 dpf (H, I). Arrows point to glial endfeet. Radial glia and their endfeet appear normal in the mutant. Scale bar (in F, for panels F-I) is 10μm.