Figure 1.
Ptf1a and Rbpjl expression during pancreatic development. (A) Immunofluorescent localization of PTF1a (green) at E10.5, E11.5, E12.5, and E13.5. (Red) E-cadherin. Arrowheads point to nascent acini. (B) Hybridization in situ detection of Ptf1a and Rbpjl mRNAs in early acinar cells around the periphery (solid arrowheads) compared with Ngn3 mRNA (open arrowheads) in endocrine cell precursors in the interior of the pancreatic epithelium at E14.5. Ptf1a and Rbpjl are for nearby, nonadjacent sections. (C) mRNAs were quantified by quantitative RT–PCR with RNA isolated from embryonic pancreatic rudiments and expressed relative to the levels at E18.5. The Rbpj and Rbpjl level mRNAs have a reciprocal relationship. Error bars are SEM; points without bars have SEMs equal to or smaller than the symbol.