Fig. 3. Immunofluorescence signals of Cx43 protein in cryosections of the Cx31^–/– epidermis (A) are significantly weaker than in the epidermis of wild-type mice (cf. Fig. 1C). (B) Immunoblot analysis of Cx43 protein in Cx31^+/+ and Cx31^–/– tail skin. Cx31^+/+ skin lysate showed about threefold more Cx43 protein than Cx31^–/– lysate. Ponceau-stained nitrocellulose membranes (C) indicated equal protein loading of the lanes shown in (B). Nuclei were stained with Hoechst 33258 fluorescent dye. The basal lamina in A is marked by white dots. Bar, 25 µm. Epidermal layers: bs, basal; co, cornified; gr, granulous; sp, spinous.