Characterization of the TGFα-expressing TG mucosa. Scale in each figure indicates 100 μm. (a) Distribution of TGFα-expressing cells. Brown-colored TGFα-positive cells were visible along the luminal pit region in the WT mucosa, the elongated foveolar pit region, and the lower one-third of the glandular region in the TG mucosa. (b) Overlap of red-colored TGFα-positive cells and green-colored H+/K+-ATPase-positive parietal cells. Lower TGFα-positive cells in cluster are distinct from the green-colored parietal cells in the TG mucosa. (c) Northern blot of human TGFα mRNA and PCR-amplified mouse TGFα mRNA. Human TGFα mRNA is expressed in the TG mucosa alone (left panel), but PCR-amplified mouse TGFα mRNA is expressed similarly in both WT and TG mucosae (right panel). (d) Western blot of TGFα intermediate forms. TGFα precursor (20 kDa) and its intermediate forms are visualized more intensively in the TG mucosa than in the WT mucosa. (e) Localization of EGF receptor in the gastric mucosa. EGF receptor (EGF-R) was stained with Cy3 (red) and H+/K+-ATPase was stained with FITC (green). EGF-R was immunostained moderately in the upper pit region and strongly in the lower glandular region similarly in both the WT and TG mucosae. (f) Distribution of metallothionein in the gastric mucosa. Metallothionein is immunostained strongly in the lower glandular region, and moderately along the foveolar region. (g) Elongation of the gastric pit of the TG mucosa. PCNA-positive cells are distributed at the upper-third region in the WT gastric glands, whereas they are distributed more numerously and broadly in the middle glandular region. (h) PAS staining shows elongated pit in the TG mucosa.