Fig. 5. Stabilization of ß-catenin causes increased pancreas organ size in PdxCre^late ß-cat^active mice. (A) Gross morphology of pancreata from a control (left) and PdxCre^late ß-cat^active mutant (right). (B) Quantitative measurements revealed a 4.6-fold increase in pancreas mass in PdxCre^late ß-cat^active mutants between birth and 1 year (n7 for each time point analyzed; control, blue; PdxCre^late ß-cat^active, orange). (C,D) High levels of ß-catenin (green) can be detected in the DAPI stained (blue) nuclei of adult PdxCre^late ß-cat^active exocrine cells (D), identified by amylase staining (red). By contrast, ß-catenin is localized exclusively to the plasma membrane of control cells (C). Scale bars: 10 µm. (E,F) Staining of pancreatic sections for the proliferation marker, phospho-histone H3 (PH3, red) and co-stained for DAPI (blue) reveals an increase in the number of proliferating cells in the PdxCre^late ß-cat^active mutant (F) when compared with control (E). Scale bars: 100 µm. (G,H) Hematoxylin and Eosin staining of adult pancreas sections from PdxCre^late ß-cat^active mice (H) reveals an increase in cell density within the exocrine pancreas, but not the endocrine islet (at center) when compared with control (G). (I) Quantification of PH3 positive cells (n=4 per genotype analyzed) indicates that the relative number of proliferating cells in the PdxCre^late ß-cat^active mutant (orange) is increased 2.5-fold over control (blue) 21 days postnatally. (J) Quantification of the relative number of nuclei per field confirms that the density of cells within the exocrine pancreas of PdxCre^late ß-cat^active mice (orange) is increased 1.8-fold over control (blue), while the endocrine cell density is normal (n=4). Confidence intervals calculated using Student's t-test. #, not significant; ^*, P<0.05; ^**, P<0.01. Error bars represent s.e.m.