Perturbation of RET signaling in the embryonic kidney

We have used a RET‐Ig fusion protein to disrupt signaling in the rat embryonic kidney development pathway. Treatment of embryonic kidney organ cultures with RET‐Ig results in a decrease in branching of the ureteric bud and a down regulation in expression of the Wnt‐11, Wnt‐4, and ld genes. These data suggest that Wnt‐11, Wnt‐4, and ld function downstream of RET signaling in normal development. Expression of BMP‐7, shh, and ptc were uneffected by RET‐Ig treatment, implying that these genes are regulated independently of ret. We have also performed immunohistochemistry with a GFRα‐1 specific polyclonal antisera to localize GFRα‐1 protein expression in the developing kidney. Dev. Genet. 24:263–272, 1999. © 1999 Wiley‐Liss, Inc.