Fig. 1. MALS-3 is expressed by and localizes to the apical surface of NPCs. (A-C) Immunostaining of E14 coronal sections of rat telencephalon with antibodies against MALS-3 (green), ZO2, F-actin or β-catenin (red) reveal the supra-apical localization of MALS-3 relative to ZO2 (A), β-catenin (B) and F-actin (C). Nuclei are stained with SYTO-11 (blue). The en face view in C shows the lumen of the ventricle at the bottom, then (from bottom to top) passes through the apical-most ends of VZ cells and into the domain occupied by adherens junctions, which appear as circles of F-actin staining. (D-L) MALS-3 is initially localized diffusely in VZ cells (D-F), but appears to adopt an apical localization at the onset of neurogenesis (E11.5, G-I), which is maintained throughout the rest of embryonic life (J-L). Scale bar: 5 µm.