Fig. 1. Characterisation of the Nß-cateninER fusion protein and generation of transgenic mice. (A) Schematic diagram showing the K14 expression cassette and Nß-cateninER transgene. (B) Anti-ER immunofluorescence staining of 3T3 cells expressing Nß-cateninER following treatment with ethanol or 4OHT for 24 hours. (C) The induction of luciferase activity after 4OHT treatment. 3T3 cells were transduced with GFP or Nß-cateninER and transiently transfected with the luciferase reporters FOPFLASH or TOPFLASH. The luciferase activity of each reporter was measured in triplicate and the s.d. is shown. (D) Anti-ER immunofluorescence staining (green) of wild-type and transgenic K14Nß-cateninER (line D4) mouse back skin, untreated and after 7 days treatment with 4OHT. Nuclei were stained with propidium iodide (red). Insets show higher magnification views of boxed areas. (E) Western blot of primary keratinocytes cultured from wild-type (WT) and transgenic (lines 3953 and D4) mice, probed with anti-ER (top panel) or, as a loading control, anti-Erk MAPK (bottom panel) antibodies. (F) Gross phenotype of wild-type and Nß-cateninER mice (line D2) treated daily for 14 days with 4OHT, showing dramatic stimulation of hair growth in the transgenic mouse. Scale bars: (B) 50 µm, (D) 100 µm (main pictures), 25 µm (inserts).