FIG 2.

Cre-mediated gene recombination is restricted to IEC in the small intestines of βNF-treated Prnp^ΔIEC mice. Female Prnp^ΔIEC mice were treated with β-naphthoflavone (βNF) for 5 days to specifically ablate Prnp expression in intestinal epithelial cells, and tissues were analyzed 14 days later. Prnp^ΔIEC mice treated with the vehicle alone (Veh.) were used as controls. (a and b) Whole-mount histological analysis of LacZ expression (blue) in the intestines of βNF-treated Prnp^ΔIEC mice (a) or vehicle-treated Prnp^ΔIEC control mice (b). S, small intestine; L, large intestine. (c and d) Histological analysis of LacZ expression (blue) in IEC and crypts in the intestines of βNF-treated Prnp^ΔIEC mice (c) or vehicle-treated Prnp^ΔIEC control mice (d). Sections were counterstained with nuclear fast red to detect cell nuclei (red). SM, submucosa. (e and f) Comparison of the percentages of LacZ-expressing crypts in the small (e) and large (f) intestines of βNF-treated Prnp^F/F control mice. Untreated Prnp^ΔIEC mice, vehicle-treated Prnp^ΔIEC mice, and βNF-treated Prnp^F/F mice were used as controls. Data represent mean percentages of LacZ-expressing crypts/mouse (n = 5 mice/group; 50 to 105 crypts/mouse). (g and h) Histological analysis of LacZ expression (blue) in Peyer's patches and colonic patches of βNF-treated Prnp^ΔIEC mice (g) or vehicle-treated Prnp^ΔIEC control mice (h). SED, subepithelial dome; Fo, follicle.