Figure 4

Expression of Dlk1 alters the cellular distribution of Notch. (A-C) M-Dlk (A,A" green, white) is present at the cortex/membrane of expressing cells and results in stabilization of Notch (A,A', B,B', C,C' red, white) within the stripe of M-Dlk expression (yellow arrows/line). (B-B") Higher magnification, cell outlines with M-Dlk and Notch enrichment are visible (e.g. arrowhead). (C-C") X/Z section, co-enrichment of Notch and M-Dlk on apical and lateral regions of cells is seen (e.g. arrowhead; note there is also non-specific accumulation of anti-Dlk staining along the surface of the specimen). (D-E) SM-Dlk (D, D"; E, E"; green, white) accumulates on the basal surface of the epithelium (e.g. arrow in E,E"), and at lower levels around the membrane/cortical regions. Less stabilisation/accumulation of Notch is detected, but there is enrichment at the cortex of some SM-Dlk expressing cells (e.g. arrowheads). (A'-E') Notch channels only, (A"-E") anti-Dlk channels only. Yellow arrows and lines indicate domain of ptc::Gal4 driven expression.