Fig. 2.

The Notch signalling pathway is active in neuroepithelial cells. (A) The intracellular domain of Notch is strongly enriched in neuroepithelial cells (to the right of the arrowhead) and downregulated in neuroblasts (arrows, to the left of the arrowhead). (B,B′) As shown by fluorescent in situ hybridisation, Tom is strongly expressed in neuroepithelial cells (green, grey) and downregulated in Dpn-positive neuroblasts (arrows, blue). Arrowhead indicates the neuroepithelial to neuroblast transition zone. Scale bars: 10 μm.