Restoration of the normal intestinal phenotype is associated with raised levels of apoptosis and down-regulation of Wnt target gene expression. (A) Apoptosis in the intestine as assessed by active caspase-3 staining (B) Number of apoptotic cells, scored using active caspase-3 stained sections in the crypt compartment from control and Tet-OΔN89β-catenin mice after 10 days doxycycline treatment and 1, 2 and 7 days following doxycycline withdrawal. (C) qRT-PCR analysis of Wnt target genes in the intestine of control and Tet-OΔN89β-catenin mice treated with doxycycline for 10 days and 1, 2 and 7 days following doxycycline withdrawal. The level of the transcripts is expressed relative to that in control animals. *Significant difference compared to control (p<0.05, Mann-Whitney, n=4-5). Dox: doxycycline.