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Fig. 2. Regionalization of the gut epithelium along the anterior-posterior axis at 7 days of development (stage 46/47). In situ hybridization to 7-day Xenopus guts showing regional expression of markers along the anterior posterior axis of the epithelium (dark blue). Left column shows the entire gut, centre column the anterior boundary (if appropriate) and the right column the posterior boundary. (A–C) Xsox2 (arrow 1 marks the stomach/transitional zone boundary and arrow 2 marks the boundary between the transitional zone and intestine). (D–F) IFABP. (G–I) Xcad 1. (J–L) Xcad 2. (M–O) Xhox3. (P) Schematic of the gut at 7 days showing the position of expression boundaries relative to differentiated tissue boundaries. Pa, pancreas; li, liver; g, gall bladder; st, stomach; si, small intestine; co, colon; pr, proctodeum. |