Fig. 6. Exogenously added FGF10 can rescue the PDX1-expressing pool of epithelial cells in cultured pancreas derived from Fgf10 mutants. Consecutive sections of explanted cultured tissue were stained for PDX1 (green) and glucagon (red). (A) Cultured explanted tissue derived from an Fgf10 mutant stained for PDX1. Very few stained cells were detected. (B) Section adjacent to A showing that glucagon-positive cells were present. (C) Explanted tissue derived from Fgf10 mutants, cultured with 50 ng/ml FGF10 and stained for PDX1. The PDX1-positive cells are present in the bud outgrowth from the foregut epithelium. (D) Glucagon-expressing cells in an adjacent section to C. (E) An additional population of PDX1-positive cells detected in the explanted tissue from Fgf10 mutants that was cultured with FGF10. (F) No glucagon-positive cells were detected in the section adjacent to that in E. (G) Cultured explanted tissue derived from a wild-type littermate and stained for PDX1. The arrow indicates an additional population of PDX1-stained cells. (H) Glucagon-positive cells in the section adjacent to that in G. The white dashed lines in D, F and H indicate the position of the PDX1-positive cells in C, E and G, respectively.