ABSTRACT
This chapter reviews the concepts of pancreas development. It describes the status of islet differentiation from mouse and human embryonic stem (ES) cells. The chapter outlines how one might begin to recapitulate developmental signals in culture to direct ES cell specification to islet lineages. It discusses remaining challenges toward generating transplantable functional islet tissue for treating diabetes. Pancreatic development is a multi-step process that requires correct endoderm patterning and pancreas specification, bud formation, branching morphogenesis and islet formation. During gastrulation, totipotent cells of the epiblast divide, differentiate, and rearrange into three distinct germ layers: ectoderm, mesoderm and endoderm. The dual primordia of the pancreas, which form the ventral and dorsal anlagen, have initial contact with different embryonic tissues. This has generally been considered an indication that some of the early inductive signaling events may be different between the two lobes.
