Fig. 5

Tectal Dendrite Stratification Requires both Robo/Slit Signaling and Collagen IV(A) In situ hybridization, showing that robo2 mRNA is expressed in both RGCs and tectal neurons.(B) Double labeling of Dlx5/6:GFP (red) expressing tectal neurons and robo2 mRNA (green).(C and D) Sections of tectum labeled with anti-parvalbumin at 6 dpf. WT tectum (C) shows four distinct laminae. No lamination is detected in ast^ti272z tectum (D).(E and F) Sections of WT (E) and ast^ti272z (F) tectum labeled with anti-parvalbuminin (red), anti-GFP (green) and DAPI (blue). Laminae are numbered in (E) as in (C).(G–I) Projections of confocal images of tectal neurons, transiently labeled with Dlx5/6:Gal4 and UAS:Dsred at 6 dpf. In the WT (G), neurites are organized into two laminae. In ast^ti272z (H), no lamination is detectable. In drg^s510 (I), the two laminae are more closely spaced, and ectopic neurites extend outside the superficial layer.(J–L) Radial glial endfeet attachment requires Col4a5. Projections of confocal images of radial glia in the WT (J), ast^ti272z (K) and drg^s510 (L) at 6 dpf.Arrows point at the endfeet anchored within the basement membrane. Asterisks (^*) indicate processes from other cells. Scale bars represent 40 μm in (A) and 20 μm in (B), (C), (G), and (J).