Fig. 4. N-cadherin-mediated inhibition of NC delamination is associated with a downregulation of cyclin D1 transcription and G1-S transition. (A-C) Brdu incorporation (red nuclei) following electroporation (green) with control-GFP (A), wild-type N-cadherin (B) and cN390-GFP (C). (D) Quantification of the percentage of Brdu+/GFP+ nuclei in the various treatments (data are the mean±s.d. of at least five embryos per treatment). Cells that received wild-type N-cadherin failed to incorporate Brdu+ and no GFP+ NC cells exited the treated side of the tube. By contrast, Brdu+ NC cells emigrate normally from control-GFP and cN390-GFP-treated hemi-tubes (arrows in A,C). Note that Brdu+ nuclei are spread across the apico-basal thickness of the NT (C) contrary to their normal localization to the basal half of the epithelium (A). (E-H) cyclin D1 mRNA (blue) is reduced in cells that received wild-type N-cadherin-GFP (G,H, green) but not in control-GFP-treated hemi-tubes (E,F) where delaminating NC cells express cyclin D1 (arrows). Scale bar: 25 µm for A-C,E,F; 30 µm for G,H.