Control of early development of the pancreas in rodents and humans: implications of signals from the mesenchyme.

During the last few years, progress has been made in the control of pancreatic development. Many transcription factors have been described in the pancreas and a genetic approach has been used to define their role in pancreatic development. Pancreatic development depends on mesodermic signals, with the initial steps controlled by signals from the notochord that is in close contact with the dorsal endoderm of the gut fated to become pancreas. Later signals from the mesenchyme that surrounds the embryonic pancreatic epithelium regulate the proliferation of immature pancreatic epithelial cells and their differentiation into endocrine or exocrine tissue. This review discusses recent data on the role the signals from the mesenchyme have in the development of the pancreas in rodents and humans.