Transcription factor implicated in the cell fate determination in various organs. Binds to the E-box consensus sequence 5'-CANNTG-3'. Required for exocrine pancreatic development. Plays a central role in directing the differentiation of retinal progenitors towards horizontal and amacrine fates. Expression detected 24 hpf (hours post fertilization), in developing hindbrain, most abundant in rhombomeres 2 and 3. Neural expression peaks at 48 hpf, at which point transcripts are found in the hindbrain, rhombic lip, and optic precursors. The exocrine pancreas represents a population of cells encircling the embryonic islet. At 72 hpf, expressed throughout the endodermal region corresponding to the exocrine pancreas. Expression is restricted to the exocrine pancreas following an early period of transient neural expression. Positive exocrine precursors and insulin-positive endocrine elements are both temporally and spatially segregated during embryogenesis.