Fig. 1. Specific ablation of Myc in keratinocytes. (A-C) Southern blotting analysis of EcoRI digested genomic DNA; the probe detects the three alleles: Myc WT (20 kb), Myclox (10 kb) and deleted Myclox (KO; 16 kb). Genomic DNA is from embryos (E; A) or (B,C) from whole tail, tongue, liver, heart, skin (S), epidermis (Ep) or dermis (D) of adult mice bearing or not Cre as indicated (+ or –). Animals were aged 4 months to 1 year. (D) RPA on RNA from epidermis of control (Ct) or KO mice to detect Myc-related mRNAs. KO underlined indicates the presence of a severe phenotype, mth (month) indicates the age of the mouse. The experiment was performed on ten different pairs of littermates from one and a half months to one and a half years of age.