Fig. 7. Co-localisation studies of AR and SM. Propidium Iodide (PI) staining of nuclei is shown in red, AR is shown in green, SM is shown in blue and the merged images are shown on the right-hand side. PI/AR co-expression results in a yellow colour. (A-D) P0 male UGT, showing urethral SM (UrSM), epithelial buds of the ventral prostate (VPE) and prostatic mesenchyme (VPM). (D) UrSM contains little or no AR, whereas that SM associated with the VPE is AR positive, as is VPM. (E-H) P0 female UGT, where UrSM and VMP are visible. AR levels in the P0 female UrSM appear lower than those observed in the VMP. (I-L) A female UGT grown in vitro in the absence of testosterone; the SM layer shows lower levels of AR than the VMP. (M-P) A P0 female UGT grown in the presence of testosterone, where levels of AR in the SM layer are similar to those in the VMP. Comparison of L and P suggests that AR expression has been upregulated in the UrSM.