BAT-gal transgene reporter assay of canonical Wnt signaling
X-gal staining of both embryos and developing kidneys was performed as previously described [21]. Care was taken to reduce endogenous β-galactosidase activity within the developing kidney by increasing pH of the X-gal staining solution to 8.0. Changes in transgene β-Gal expression were quantitated using a β-Gal ELISA (Enzyme-linked immunoassay) kit (Roche, Indianapolis, IN), normalizing according to total protein. Each genotype was represented by a sample size of 4 except the non-transgenic (n = 5), Pygo1+/- ; Pygo2+/+ (n = 6), Pygo1-/- ; Pygo2+/- (n = 8), and Pygo1-/- ; Pygo2-/- (n = 6) groups.