Fig. 3. Abnormal esophagus phenotype of hypomorphic mutants at P0. Sections of esophagi of wild type (A-D) and Sox2^EGFP/LP compound mutants (E-H) stained with haematoxylin and eosin (A,E), anti-Keratin 14 (B,F), Alcian blue (C,G), and anti-Muc5AC (D,H). (I) Semi-quantitative RT-PCR for expression in mutant esophagi of several glandular stomach- and intestine-specific genes. Tff1, Tff2 and Muc5B are normally specifically expressed in posterior (antral/fundic) stomach (P-stomach), not in forestomach (A-stomach). Agr2 is normally expressed in both posterior stomach and intestine. Clca3, Reg3g and Cdx1 are normally expressed in intestine. ß-actin is internal control for RT-PCR. Scale bars: 50 µm in A-H.