Fig. 2.

Development of the renal cortex and patterning of the ureteric bud epithelium are normal in Wnt7b mutants. In situ hybridization to E15.5 kidney sections to examine branching morphogenesis (Wnt11), nephrogenesis (Wnt4), cortical stroma progenitors (Foxd1), nephron number and nephron patterning (Gsh1 for podocytes, Slc34a1 for proximal convoluted tubules, and Slc12a3 for distal convoluted tubules) indicates that these processes were unaffected in Wnt7b mutants. The expression of Wnt11 at the branching tips of the ureteric epithelium, Wnt9b in the non-tip ureteric epithelium, Wnt7b in the more-distal ureteric epithelium, renal pelvic epithelium and ureter, Foxa1 in the prospective medullary collecting ducts, renal pelvic epithelium and ureter, and Foxi1 in intercalated cells of the maturing collecting duct demonstrate normal stratification and differentiation of the ureteric epithelium in Wnt7b mutants. The Wnt7b riboprobe was generated from part of the exon 4 sequence and thus detected Wnt7b mRNA signals in both control and Wnt7b mutant kidneys. Scale bar: 200 μm.