Fig. 7. Wnt CM induces the accumulation of ß-catenin in nuclei. (A) Explants were pre-stimulated by 50 ng/ml FGF2, followed by stimulation with control medium or Wnt3a CM for 5 days. Explants were immunolabeled with anti-ß-catenin or Hoechst 33258 to stain nuclei. ß-catenin accumulated in the nuclei of cells that elongated after treatment with FGF2/Wnt CM (b; arrow), but not in the nuclei of morphologically normal cells cultured with control medium or FGF2/control medium (a). Scale bar: 10 µm. (B) Nuclear extracts were prepared from explants cultured with FGF2/control medium (F/C) or FGF2/Wnt CM (F/W). Western blotting was performed with anti-ß-catenin. Explants displayed an increased level of nuclear ß-catenin in response to FGF2/Wnt CM. Blots probed with an anti-lamin A/C antibody demonstrated equal loading of nuclear proteins.