Fig. 8. Expression of Bb1C and Bb2C in the late neurula. (A-C) A stage N3 embryo was triple-stained for Bb.ß-catenin (A), Bb1C (B) and Bb2C (C). Anterior is to the left. Dorsal is to the top. Bb1C was detected in the nerve cord (Nc) and differentiating notochord (No), but not or only faintly in the endoderm (En). Bb2C was detected in the notochord and endoderm, but not or little in the nerve cord. Note that in the notochord, the pattern of Bb1C expression differs from that of Bb.ß-catenin and of Bb2C (fat and thin arrows). (D) High magnification of the area boxed in B. The images for Bb.ß-catenin (green) and Bb1C (purple) were colored and merged. Bb1C colocalized with Bb.ß-catenin appears white (arrow). Arrowheads indicate the apical concentrations of Bb1C in the nerve cord (Nc) epithelial cells. (E,F) High magnification of the area boxed in A. In E, the images for Bb.ß-catenin (green) and Bb1C (purple) were colored and merged. In F, the image for Bb2C is shown. Arrows indicate interfaces between notochord dorsal (NoD) cells, at which Bb2C was detected, and arrowheads indicate interfaces between notochord ventral (NoV) cells and between notochord mid (NoM) cells. Some of the Bb1C and Bb2C signals were closely located. Note that NoM cells are interdigitated between the NoD and NoV cell layers. (G) Dorsolateral view of a stage N3 embryo stained for Bb.ß-catenin. Anterior is to the left. A single line of NoD cells is seen. The arrow points to the posterior region of the notochord, where NoM cells have not interdigitated. Scale bars: 20 µm.