Fig. 8. Constitutively active Notch1 promotes proximal tubule formation while inhibiting the progenitor from differentiating into podocytes and distal tubules. (A) Notch1 activation in the mesenchyme causes renal hypoplasia at E17.5. (B) The ureteric bud branches only once. Subsequent planes of sectioning are marked (a-c). Ck8 is visualized using Cy3, but the image is pseudocolored to correspond with Ba-Bc. (C,C') E11.5 metanephroi from mutant (C) or wild type (C') were cultured for 4 days, stained with LTL (green) and Ck8 (red). (Ba-Bc) Serial sections of the mutant kidney stained with markers for renal tubules. Arrowheads locate the same cells in adjacent sections. Scale bars: A,B,C,C', 0.5 mm; Ba-Bc, 0.1 mm.