FIG. 4.

Increased proliferation in Ptk6^−/− intestine. A. BrdU incorporation is increased in crypts of Ptk6^−/− mice. Antibody binding was detected with DAB (brown), and sections were counterstained with hematoxylin (blue). B. The average number of BrdU-positive cells per crypt is significantly higher in Ptk6^−/− small intestine (P = 0.037). Error bars indicate standard deviations. C. PCNA immunoreactivity is not restricted to the crypt compartment in PTK6-deficient mice. PCNA-positive epithelial cells are detected in villi of Ptk6^−/− mice. Bars, 50 μm.