Confocal analysis of Pygo1 / Pygo2 mutant E18.5 kidneys. (B, D) Pygo1
-/- mutant E18.5 kidneys and (A, C) kidneys of normal littermates were stained using antibodies to (C, D) Cited1 or (A, B) Wt1, both expressed in the condensing metanephric mesenchyme, and colored as red, Cdh1, a general marker of epithelia (blue), and DBA lectin staining the ureteric tree . Confocal Z-sections were obtained every 5 μm for 75–80 μm. A reduced number of ureteric tips per area was observed in (B, D) the Pygo1/Pygo2 null kidneys compared with (A, C) control littermates. In addition, ureteric bud tips were often more dilated in Pygo1/2 null mutants compared with controls. The condensed mesenchyme surrounding the ureteric bud was also significantly expanded in the mutants. Original magnification × 200.