The angioblasts at the foregut endoderm migrate from the lateral plate mesoderm in response to CxCl12 signals. These angioblasts are positive for both Cxcr4 and Lmo2.
Recent work on the chick embryo demonstrated that the chemokine ligand CxCl12 is expressed in the foregut endoderm before Pdx1(the earliest pancreatic marker) expression. CxCl12 signals to the lateral plate mesoderm, thereby attracting these angioblasts. In response, the angioblasts migrate to the endoderm border and signal via an unknown mechanism to induce Pdx1 expression in the foregut endoderm. It remains unclear if these cells are the source of pancreatic blood vessels or merely participate in epithelial specification.
EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
