Notch signaling is spatially activated within differentiating embryonic epidermis. (A) Confocal images of basal or suprabasal planes from WM E17.5 epidermis isolated from TNR-GFP mouse. Green, GFP; blue, DAPI. (B) Sagittal section of E17.5 epidermis immunolabeled with antibody against Notch 1 intracellular domain (NICD1). (C) Sagittal section of E17.5 epidermis immunolabeled with antibodies against Notch ligand Jagged 1 (green) and basement membrane glycoprotein NIDOGEN (red). (D) Sagittal section of E17.5 epidermis immunolabeled with antibodies against E-cadherin (green) and HES1 (red). Dotted line denotes dermal–epidermal border. Bars: (A) 15 µm; (B–D) 30 µm.