Immunofluorescent labeling for Pdx1, Sox9, Nkx6.1, Ptf1a, Ngn3 and E-cadherin (Ecad) in emerging trunk and tip domains of developing mouse pancreas. Hnf1β and Nkx6.1 become progressively restricted to the central trunk region of the branching pancreatic epithelium, from which Ngn+ cells begin to emerge. In contrast, Ptf1a is restricted to peripheral tips. As late as E13.5, Pdx1 and Sox9 are expressed in both central trunk and and peripheral tip domains.