Notch gene expression during pancreatic organogenesis

Notch receptors are involved in regulating the balance between cell differe ntiation and stem cell proliferation during the development of numerous tis sues (Artavanis-Tsakonas, S., Matsuno, K., Fortini, M.E., 1995. Notch signa ling. Science 268, 225-232). Here the expression of all four vertebrate Not ch genes, their ligands, and some down-stream targets is analyzed during mo use pancreatic organogenesis. Notch I is the first Notch gene expressed in the pancreatic epithelium, and coexpression with HES 1 suggests that the No tch 1 pathway is activated. Notch 2 expression follows later when pancreati c buds branch and is restricted to embryonic ducts, believed to be the sour ce for endocrine and exocrine stem cells. Notch 3 and Notch 4 are expressed in pancreatic mesenchyme and later in endothelial cells. Together these de scriptive data comprise a framework for understanding the cellular basis fo r Notch function during pancreatic development. (C) 2000 Elsevier Science I reland Ltd. All rights reserved.