Fig. 7. Expression of Bb.ß-catenin and Bb1C during neurulation. The embryos were double-stained for Bb.ß-catenin (A,C,E) and Bb1C (B,D,F). Anterior is to the left. (A,B) Dorsal surface view of a stage N1 embryo at the same focal plane. Signals for Bb.ß-catenin and Bb1C were detected at cell-cell contact sites in both the epidermal ectoderm (Ep) and the neural plate (Np). In cells at the edges of the epidermal ectoderm spreading over the neural plate (arrows), the characteristic concentrations of Bb1C and Bb.ß-catenin were poorly observed. Note that Bb2C was not detected during neurulation as shown in Fig. 6B. (C-F) Dorsal surface (C,D) and internal (E,F) views of a stage N2 embryo. The focal plane of E and F is separated from that of C and D by 9 µm. At the dorsalmost epidermal ectoderm, weaker levels of Bb1C were observed compared to more lateral areas, although the levels of Bb.ß-catenin showed no apparent differences (arrows in C and D). In the folded neural plate, Bb1C, together with Bb.ß-catenin, was highly concentrated at the apical sites of cell-cell contact (arrows in E and F). Nr, neuropore. Scale bar: 20 µm.