Fig. 7. (A,B) Dissected stomachs from E18.5 embryos were longitudinally sectioned and stained with Hematoxylin and Eosin. The thickness of the glandular epithelium is increased in the mutant stomach compared with the littermate control. (C-F) The adjacent tissue sections between fore-stomach and hind-stomach were stained by anti-H⁺/K⁺-ATPase ß-subunit antibody (C,D) and anti-GATA4 (E,F) antibodies. The transition zone between oxyntic mucosa (os) and stratified squamous epithelium (sse) of the fore-stomach are indicated by arrows. (G-T) Marker gene analyses in the adult stomachs: (G-L) Sections (4 µm) prepared from the stomachs of 35-day-old mice were staining with Hematoxylin and Eosin. The histological morphology of zymogenic region (G,H), mucoparietal zone (I,J) and pure mucus zone (K,L) showed no obvious difference in the conditional mutant stomach (H,J,L) and littermate control (G,I,K). (M,N) The secreted glycoprotein of the zymogenic zone of stomachs was visualized by PAS staining and no discernable difference was observed in the conditional mutant stomach (N) and littermate control (M). (O,P) The gastric parietal cells were stained with anti-H⁺/K⁺-ATPase ß-subunit antibody. (Q,R) The neck and pre-neck cells (red) at the gastric units showed no difference in the control (Q) and conditional mutant (R) stomachs. (S,T) Anti-GATA4 antibody was used to mark glandular gastric epithelium. Positive signals were found in base of glandular gastric epithelium at pure mucus zone in the control (S) and the mutant (T).