Figure 1. Xenopus ndrg1a is expressed early in the archenteron roof endoderm and late in pancreas, oesophagus, stomach, and duodenum primordia, as revealed by whole mount in situ hybridization.

(A) Lateral view of a blastula. (B) Whole mount in situ hybridization on bisected stage 18 neurula, anterior toward the left. (C–E) Lateral view, head toward the left. Note that the foregut ndrg1a signal in E covers pharynx, oesophagus, pancreas, stomach, and duodenum. (F, G) Transversal sections of a stage 28 embryo at the levels illustrated by the dashed lines in E. (H, I) Lateral view, head toward the left. (J) Ventral view, head toward the left. Abbreviations: ar, archenteron roof endoderm; de, dorsal endoderm; dp, dorsal pancreatic bud; ey, eye; gb, gall bladder; osd, oesophagus, stomach and duodenum anlagen; p, proctodaeum; pa, pancreas; pd, pronephric duct; ph, pharynx; pr, pronephric anlage; pt, pronephric proximal tubules; vp, ventral pancreatic bud.