The pre-pancreatic foregut endoderm cells of the dorsal foregut are the first cells in this region to display pancreatic gene expression during development. They give rise to the pancreatic progenitor cells of all pancreatic cell types. The pre-pancreatic foregut endoderm cells are located in the pancreatic region of the endoderm and in the pancreatic buds.
PDX1 expression in the human embryonic dorsal foregut endoderm occurs at CS12 (30dpc), along with other transcription factors important for pancreatic differentiation: GATA4, FOXA2 and SOX17.
In the human, budding begins at CS13 (30-33 dpc) in PDX1/GATA4/ SOX9-positive regions. At this stage, NKX6.1 expression begins in the dorsal bud, but neither SOX17 nor NKX2.2 expression is detected yet.
EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
