Fig. 7. Cells within S-shaped bodies die in Fgf8 hypomorphs. (A-D) Immunofluorescence assay for PAX2 (green), to identify the developing nephrons and collecting ducts, and LysoTracker (LysoT, red) staining to identify regions containing dying cells in vibratome sections of normal and Fgf8 severe hypomorph kidneys at the stages indicated. (A'-D') Higher magnification views. Arrows indicate regions where Bowman's capsule progenitors are dying in normal and mutant kidneys; white arrowhead indicates regions where tubule progenitors are dying in the mutant kidney; open arrowheads point to regions in the peripheral zone of the mutant kidney where cells are dying.