Stabilization of ß-catenin during murine Kidney Development

We define a pathogenic role for a ß-catenin-activated genetic pathway in murine renal dysplasia. Cre-mediated stabilization of ß-catenin in the ureteric cell lineage prior to the onset of kidney development increased ß-catenin levels and caused renal aplasia or severe hypodysplasia. A genome-wide analysis of mRNA expression in dysplastic tissue identified down-regulation of genes required for ureteric branching and up regulation of Tgfß2 and Dkk1. Hoxb7-Cre:EGFP mice ( Zhao, et al. (2004) Dev Biol 276:403-415) were crossed with mice containing loxP sites flanking exon 3 of the ß-catenin allele (ß-catdelta3/delta3) (Harada,et al. (2002) Cancer Res 62:1971-1977) to generate ß-catenin gain-of-function mutant mice specific to the uteric bud, termed ß-catGOF-UB .Eighteen ß-catGOF-UB mutant kidneys and 9 WT kidneys were micro-dissected at E12.5. Mutant kidneys were divided into three random pools (n=3) consisting of 6 kidneys each and mRNA expression assessed by microarray.