Fig. 4. Metanephric development in control (A,C,E,G) and T-Cre; Fgf8^Flox/2,3 (B,D,F,H) progeny stained with Hematoxylin and Eosin. (A,B) At E12.5, control (A) and mutant (B) kidneys show similar patterns of ureteric bud (UB) branching and induction of metanephric mesenchyme, with condensation and renal vesicle formation (arrowheads). (C,D) At E14.5, mutant kidneys (D) show renal vesicles, which do not progress, unlike controls (C) in which S-shaped bodies (s) and glomeruli (g) are evident. This pattern persists at E16.5 (E,F), and, by E18.5 (G,H), only radii of UB branches remain in mutants (H). Scale bars: 100 µm.