TRANSCRIBING PANCREAS

For similar to 30-35 years, our insight into some of the fundamental a spects of pancreas development has been based mainly on two independen t studies performed in the 1960s by Golosow and Grobstein and Wessells and Cohen. By performing classical embryological experiments, these t wo reports described the morphogenesis of the pancreas and the epithel iomesenchymal interactions that are required for proper pancreas devel opment. In the 1970s, the groups of LeDourain and associates and Rutte r and associates showed, importantly, that despite their similarities with neurons, the pancreatic endocrine cells, like the exocrine and du ctual cells, were of an endodermal origin. Then during the 1980s, stud ies pioneered by Rutter, but also performed by many other groups, mere focused on the transcriptional regulation of endocrine and exocrine g enes. This eventually lead to the cloning of various transcription fac tors. By using a genetic approach to study the function of these trans cription factors, new insights into pancreas development have now emer ged that, on a molecular level, are beginning to explain some of the e arlier observations. This review discusses our current knowledge of th e mechanisms by which the various pancreatic cell types are generated.