Transcription profiling of mouse Ngn3-expressing pancreatic cells in a time series through embryonic development and adult islet cells

Neurogenin3 (Ngn3) is a basic helix-loop-helix transcription factor which is expressed in scattered cells in the embryonic pancreas. Mice deficient for Ngn3 fail to produce any pancreatic endocrine cells and die shortly after birth. Expression of transcription factors critical to pancreatic development (Isl1, NeuroD, Pax4, and Pax6) is missing and endocrine precursors are absent in mutant pancreatic epithelium. This study utilizes mice which were engineered to contain EGFP (Enhanced Green Fluorescent Protein) under the control of the Ngn3 promoter. In this way, cells which express Ngn3 can be FACS sorted and studied throughout embryonic development (E13.5, E14.5, E15.5, E16.5, and E17.5). EGFP positive cells from the embryonic time-points in addition to adult islets (no cells expressing Ngn3) were hybridized to the BCBC PancChip 6.0 expression microarray, thus generating a profile of gene expression during this critical stage of development of the endocrine pancreas.