Targeted ablation of AP-2α and AP-2γ in mouse skin. γ-cKO, α-cKO, and DcKO mice were compared with WT littermates. (A) Immunolocalization of AP-2α and AP-2γ in P0 skins. Color coding of markers is according to secondary antibodies used in detection; nuclei were counterstained with DAPI (blue). Solid white lines denote skin surface. Dotted lines denote dermoepidermal boundary. Note that DP (arrows) also express AP-2γ. Bars, 20 μm. (B) Immunoblot analyses with monospecific antibodies and real-time PCR on mRNAs were performed on P0 epidermis, enzymatically separated from the dermis/HFs. Molecular mass of proteins is shown. PCR primer sets were specific for the AP-2α and AP-2γ sequences targeted for deletion. DcKO real-time PCR values were consistently below the level of detection from three or more independent experiments. (C) P0 mutant mice and their WT littermates. (D and E) Histology and ultrastructure of P0 epidermis. Vertical bars in D represent epidermis thickness. Boxed areas in E are magnified in bottom panels. BL, basal layer; Sp, spinous layer; Gr, granular layer; SC, stratum corneum; der, dermis; KF, keratin filament; KG, keratohyalin granules. Bars, 10 μm. (F) Barrier assay, as determined by penetration of blue dye.