Figure 1. The secondary transition of the stomach.

A: Regions of the stomach at E17.5. G.C: greater curvature, L.C. Lesser curvature. B: Co-staining of H⁺/K⁺-ATPase (green), Pepsinogen C (blue) and E-cadherin in E16.5 stomach. The numbers refer to pictures in D). C: Multiplex RT-PCR of expression of Chromogranin A (Chrg A), H⁺/K⁺ ATPase (Atp4b), pepsinogen C (Pgc) and Trefoil Factor 1 and 2 (Tff1 and Tff2). a-tubulin (a-tub) was used as an internal control. The shown bands are representative examples from two experiments. Ages analyzed included E14.5, E15.5, E16.5 E17.5 and E18.5. (n=2/gestational time point). D: Immunohistochemistry for H⁺/K⁺ ATPase and Pepsinogen C or Chromogranin A co-stained with E-cadherin at E15.5 (top row) and E16.5 (bottom row). Numbers refer to positions in B). Insert 2 shows one forming gland with both pepsinogen and H⁺/K⁺ ATPase expressing cells. This was the only one found (n=3).