Castration of adult male mice was performed using standard techniques. For tamoxifen induction of Cre activity in mice containing Nkx3.1CreERT2/+, mice were administered 9 mg/40 g tamoxifen for 4 consecutive days. For prostate regeneration, physiological levels of testosterone (1.875 µg/hr) were administered for four weeks by subcutaneous implantation of mini-osmotic pumps (Alzet)45 (link). When included, BrdU (100 mg/kg) was administered once daily during the first three days of regeneration. For single-cell transplantation, single YFP+ cells were isolated by mouth-pipetting under epifluorescence illumination from a dissociated prostate cell suspension obtained from castrated and tamoxifen-induced Nkx3.1CreERT2/+; R26R-YFP/+ mice. A single YFP+ cell (or YFP− cell as a control) was recombined with 2.5 × 105 rat urogenital sinus mesenchyme cells in a 10 µl collagen pad, followed by transplantation under the kidney capsule of nude mice and harvesting after 10–12 weeks.
Cryosections were stained with primary antibodies as listed in