Fig. 5. Aberrant cell death occurs in T-Cre; Fgf8^Flox/2,3 kidneys. Confocal imaging of metanephroi from control (A,C,F) or T-Cre; Fgf8^Flox/2,3 (B,D,E,G,H) embryos at E12.5 (A,B), E14.5 (C,D,E), E16.5 (F,G,H) stained with the acidotrophic fluorochrome Lysotracker Red. E and H are enlargements of the boxed regions in D and G, respectively. D shows a preferential loss of mesenchymal cells from the cortical nephrogenic zone (also arrows in D and G). H shows a loss of tubular epithelial cells (arrowheads) in mutant tissues.