Fig. 7. N-cadherin cytoplasmic tail (CTF2) stimulates cyclin D1 transcription and NC emigration. (A) Delamination of NC cells that received CTF2-GFP (arrows); CTF2-GFP+ delaminating cells co-express HNK-1 (arrows, left insert) and Brdu (arrows, right insert). (B) Quantification of NC delamination. Results represent the mean±s.d. of 5 embryos per treatment normalized to control values. (C,D) The transfected hemi-tubes and delaminating NC (arrows) reveal enhanced ß-catenin and cyclin D1 transcription (n=4 and 7, respectively); note the round appearance of the overexpressing cells. (E,F) Anti-GFP and phase-contrast images, respectively, showing that CTF2-GFP is enriched in nuclei of emigrated NC cells (arrows; n=8). (G-J) Electroporation of neural tubes with CTF2 followed by explantation in the presence of GI254023X. All explants were stained with antibodies directed to the intracellular domain of N-cadherin that also react with transfected CTF2 evident in cell nuclei. (G,H) Explants that received control-GFP and GI254023X (n=13). Note that cells retain membrane-bound N-cadherin immunoreactivity and are adhered to each other. (I,J) Explants treated with CTF2 and GI254023X (n=14). Note that cells expressing CTF2 in their nucleus (arrows in I and higher magnification in J) have emigrated from the tube, lack membrane immunostaining and are detached from each other. By contrast, untransfected cells in the same field still express membrane N-cadherin and are epithelial (I, compare left and right sides). Similar results were obtained upon transfection of CTF2 alone (data not shown; n=12). Scale bar: 35 µm in A (25 µm in left insert; 33 µm in right insert); 25 µm in C,D; 15 µm in E,F; 40 µm in G,I; 17 µm in H,J.