Figure 5.

 Increase in the number of apoptotic cells in the BETA2 −/− endocrine pancreas. X-Gal-stained E17.5 and P0 pancreatic sections were subjected to TUNEL assay. For each individual animal, the numbers of cells positive for apoptosis and/or X-gal were counted from five slide sets of four serial 7-μm sections, which included an average of five islet clusters per section. Results are the average of numbers from three different animals and are shown as percent of the number of endocrine cells; error bars represent standard deviation. At P0 there were ∼14-fold more (P < 0.00001, n = 3) apoptotic cells in the −/− endocrine pancreas (B,C) than in its +/− counterpart (A,C). However, at E17.5 (C), the −/− endocrine pancreas already showed a tendency of having fivefold more (P = 0.0204, n = 3) apoptotic cells than its +/− counterpart. Two-sided Student’s t-test was used to determine the significance of the differences.