Figure 6.

De novo expression of Msx1 in the Apc-deficient colon. Immunohistochemical staining of Msx1, PCNA, and mucin 2 in wt (control), Apc^cKO/cKO Villin-CreERT2 (Apc^KO/KO Msx1^+/+), and Apc^cKO/cKO Msx1^cKO/cKO Villin-CreERT2 (Apc^KO/KO Msx1^KO/KO) mice 7 days after tamoxifen administration. Notice the absence of PCNA staining in the crypts close to the colonic surface upon Msx1 inactivation (black arrowhead). In contrast, production of goblet cells marker mucin 2 is impaired in the hyperplastic epithelium irrespective of the Msx1 gene status. The histological analysis was performed using samples obtained from nine animals (three for each genotype); representative images are shown. Sections were counterstained with hematoxylin. Boxed areas are magnified in the insets. Scale bar: 0.15 mm.