Fig. 3.

Ctip2 is required for keratinocyte differentiation induced by growth factor depletion and by Ca²⁺-induced terminal differentiation. (A) Keratinocytes cultured in growth medium (GM) were depleted of growth factors overnight and treated with 0.2 mM CaCl₂ for the indicated times before harvest for immunoblotting analyses using antibodies against Ctip2, Ki67, K10, LOR, FLG, E-cadherin, p21, Notch1, cleaved Notch1 (cNotch1), K14 and β-actin. (B) Time course (0–48 hrs) of the cell–cell junction formation and stratification following a Ca²⁺ switch in WT (left) and Ctip2-KO (right) cells was determined by immunofluorescence using anti-phalloidin (red) and anti-E-cadherin (green) antibodies. Scale bar: 25 µm. (C) Immunofluorescence staining of E14.5, E16.5, and E18.5 skin sections from WT (left) and Ctip2-KO (right) embryos with anti-E-cadherin (green) and anti-phalloidin (red) antibodies. The nuclei were counterstained with DAPI (in blue). Scale bar: 20 µm. The results are representative of at least three independent studies.