Figure 6. Wnt9b signals through the noncanonical pathway to regulate tubule diameter.

Western blots of total protein extracted from wild-type and Wnt9b^neo/neo kidneys probed with an antibody specific to the dephosphorylated (active) form of β-catenin show no significant differences in canonical Wnt activity compared to wild type (a). Section in situ hybridization with a probe for the β−catenin target axin-2 also shows no significant decrease in canonical activity in P1 Wnt9b^neo/neo kidneys (c) compared to wild type (b). Note that there is no ectopic axin2 expression in cystic proximal tubules (asterisks in c). (d) Western blots indicate that activated Rho is significantly decreased in Wnt9b^neo/neo kidneys at P1 relative to total (+GTP control) Rho levels. Addition of GDP (+GDP) to inactivate Rho was used as a negative control. Phosphorylated Jnk2 is also significantly decreased in the Wnt9b^neo/neo kidneys at P1 relative to total levels of Jnk2 (d). Blots shown are representative examples of data gathered from at least 3 different blots from 3 independent protein extractions.