14 dpc male mouse UGS explants were grown for 7 days in media containing androgen (10nM, dihydrotestosterone, DHT) and vehicle alone (0.1%DMSO) or vehicle containing trichostatin A (10–100nM TSA). (A) In situ hybridization was used to visualize NK3 transcription factor locus 1 (Nkx3-1, purple), which marks prostatic bud epithelium and immunohistochemistry (IHC) was used to visualize E-cadherin (orange), which marks UGS epithelium. (B) Prostatic bud number and (C) buds undergoing branching morphogenesis and (D) number of tips per bud undergoing branching morphogenesis were quantified from n=5 UGSs per group. Results are mean ± SEM. Asterisk indicates significant differences (p ≤ 0.05) from control, arrowheads and insets indicate representative buds undergoing branching morphogenesis.