Wnt gene expression and action during rat prostate development. A: reverse-transcriptase polymerase chain reaction revealed expression of Wnts 2, 2b, 4, 5a, 7b, and 11 as well as Fzd 2 and 4 and Dsh 1 in the day 3 rat ventral prostate. B: Contralateral rat ventral prostate lobes were collected on the day of birth and cultured in the presence of 10nM testosterone with bovine serum albumin or 0.01 µg/ml Dkk1 for 4 days. This was repeated in 4 separate prostates. The data shows a growth promoting effect of canonical Wnt inhibition by Dkk1 protein.