Spatial distribution of Scube1 mRNA in male and female UGT. (a,b) Whole-mount in situ hybridization showing Scube1 transcript expression in E18.5 male (M) and female (F) urogenital tract (panel a shows lateral view and panel b shows dorsal view). Scube1 mRNA was present in a subset of the urogenital mesenchyme including the VMP (marked by arrows in male and female). In females there was staining in the mesenchyme of the Mullerian duct (MD). In males, the seminal vesicle (SV) mesenchyme showed little or no staining. In both sexes the urethra (Ur) and urethral mesenchyme were negative for Scube1 mRNA. (c,d) P0 male urogential tract. The mesenchyme of the dorsal prostate (DP), dorsolateral prostate (DLP), and ventral prostate (VP) showed Scube1 transcript expression. In panel d, DLP is shown on the left hand side and epithelial buds (arrows; negative for Scube1) can be seen entering the DLP mesenchyme. On the right hand side of panel d ventral prostate is shown, and Scube1 transcripts are abundant in the mesenchyme and show enrichment in the peripheral mesenchyme.