title: Direct evidence for the pancreatic lineage: NGN3+ cells are islet progenitors and are distinct from duct progenitors.
abstract: The location and lineage of cells that give rise to endocrine islets during embryogenesis has not been established nor has the origin or identity of adult islet stem cells. We have employed an inducible Cre-ER(TM)-LoxP system to indelibly mark the progeny of cells expressing either Ngn3 or Pdx1 at different stages of development. The results provide direct evidence that NGN3+ cells are islet progenitors during embryogenesis and in adult mice. In addition, we find that cells expressing Pdx1 give rise to all three types of pancreatic tissue: exocrine, endocrine and duct. Furthermore, exocrine and endocrine cells are derived from Pdx1-expressing progenitors throughout embryogenesis. By contrast, the pancreatic duct arises from PDX1+ progenitors that are set aside around embryonic day 10.5 (E9.5-E11.5). These findings suggest that lineages for exocrine, endocrine islet and duct progenitors are committed at mid-gestation.
authors.affiliation: Department of Molecular and Cellular Biology, and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Gu
authors.forename: Jolanta
authors.initials: J
authors.lastname: Dubauskaite
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Melton
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D019070:Cell Lineage; D004627:Embryonic Induction; D004703:Endocrine System / Q000166:cytology / Q000196:embryology; D018398:Homeodomain Proteins; D007515:Islets of Langerhans / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D010179:Pancreas / Q000166:cytology* / Q000196:embryology* / Q000254:growth & development; D010183:Pancreatic Ducts / Q000196:embryology; D013234:Stem Cells / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D015534:Trans-Activators; C407737:Neurog3 protein, mouse; C084010:pancreatic and duodenal homeobox 1 protein