Fig. 6. Formation of the intercellular junctional complex at the apical side of the neuroepithelium. (A,D) Toluidine Blue staining of the wild-type and Hes1;Hes5 double-mutant neuroepithelium at E8.5. (B,C,E,F) TEM analysis of the wild-type and Hes1;Hes5 double-mutant neuroepithelium at E8.5. The junctional complex (arrowheads) is formed at the apical side of the neuroepithelium in both wild-type (B,C) and Hes1;Hes5 double-mutant embryos (E,F). Kissing points of the tight junction are indicated by arrows (C,F). (G-L) At E8.5, the adherens junction molecule N-cadherin and the tight junction molecules claudin-15 and -18 are expressed at the apical side of the neuroepithelium in both wild-type (G-I) and Hes1;Hes5 double-mutant embryos (J-L). Scale bars: 100 µm in A,D,G-L; 500 nm in B,E; 50 nm in C,F.