Developmental biology of the pancreas

All pancreatic cell types (endocrine, exocrine, and ductal) are derived fro m the same endodermal dorsal and ventral anlage, which grow together to for m the definitive pancreas. Golosow and Grobstein were pioneers in the field of pancreatic developmental research, as were Wessells and Cohen, who alre ady in the 1960s performed classic embryological experiments describing the morphogenesis of the pancreas and the epithelio-mesenchymal interactions t hat are instrumental for proper pancreas development. Recent findings sugge st that follistatin and fibroblast growth factors represent some of these k ey mesenchymal factors that actively promote at least pancreatic exocrine d evelopment. The true endodermal origin of the pancreatic endocrine cells be came evident by experiments performed by the groups of LeDouarin and Rutter in the 1970s. The newly acquired insights regarding the specification of p ancreatic endocrine cells as controlled by the notch signaling pathway (i.e ., similar to the mechanisms by which neurons are specified during neurogen esis) have provided a novel understanding of the long acknowledged similari ties between neurons and the pancreatic endocrine cells. Last, the identifi cation of a number of distinct transcription factors operating at various l evels of pancreatic development and in different cell types has provided us eful information both on pancreas development and on various pancreatic dis orders such as diabetes. Interestingly, four of the hitherto defined five d ifferent maturity-onset diabetes of the young (MODY) genes correspond to tr anscription factors, and, in addition, several transcription factors have a lso been linked to type 2 diabetes.