Fig. 4. MALS is required for the maintenance but not establishment of the apical localization of PALS1 and PATJ during corticogenesis. (A-H) Coronal sections of control and MALS^TKO mutant brains at E13.5 immunostained for MALS (A,B), PALS1 (C,D), CRB (E,F) and PATJ (G,H) reveal loss of MALS (B) and apical PATJ (H) relative to control. Coronal sections of control and MALS^TKO mutant brains at E18.5 immunostained for aPKC (I,J), PALS1 (K,L), CRB (M,N) and PATJ (O,P) reveal loss of apical PALS1 (L) and PATJ (P) in MALS^TKO mutants. Scale bar: 10 µm. (Q) No changes were observed in total protein levels for any of the above proteins in MALS^TKO mutant brains relative to controls.