β-Catenin is required for prostate growth and branching.

<p>(A) immunohistochemistry (IHC) on sections of <i>β-Cat;Nkx3.1:Cre</i> mutant and control E18.5 UGS with a β-Catenin antibody. Adjacent panels show high magnification of buds. Note the strong staining in the buds of control prostates that is lost in most cells of mutant prostates. Far right panel is high magnification of a bud that has not lost β-Catenin, indicated with a black arrow. (B) double IHC for β-Catenin and LEF1 on <i>β-Cat;Nkx3.1:Cre</i> and control E18.5 UGS sections. Strong nuclear LEF1 expression is observed in control prostatic buds, but lost in mutant buds. Adjacent panels show buds at high magnification. White outline indicates bud. White cells are autofluorescence from red blood cells. (C) X-gal staining of <i>ROSA-LacZ β-Cat;Nkx3.1:Cre</i> and control prostate organ cultures grown for 5 days. (D) quantitative analysis shows a significant decrease in the total number of prostatic ducts in <i>β-Cat;Nkx3.1:Cre</i> mutants (p = 0.0068, n = 5). Error bars represent standard deviation.