Fig. 7. Structural elements necessary for full barrier acquisition in K5-Klf4 DTs. Profilaggrin, filaggrin, involucrin and loricrin expression in E16.5 epidermis of wild-type and K5-Klf4 DTs. (A) Profilaggrin processed to filaggrin is not detected in wild-type epidermis until after the permeability change (E17.5), but is already processed in all of the E16.5 K5-Klf4 DTs. (B) Involucrin levels do not change during barrier acquisition and there is no difference between the wild-type and K5-Klf4 DTs. (C) Loricrin levels are slightly decreased in K5-Klf4 DT lines 2 and 6. (D,E) Ponceau S stainings; p84 expression was used as a control.