part of part of develops from develops from has potential to develop into has potential to develop into prostate gland prostate bud A region of the fetal urogenital sinus epithelium destined to become the prostate[GO]. AR activation releases instructive signals from UGM that acts on UGS epithelium (UGE) to stimulate cell proliferation, form prostate ductal progenitors (prostatic buds), and regulate cell adhesion dynamics to permit prostatic bud outgrowth. There are three phases of prostatic budding: (1) the specification phase, when instructive developmental cues define where buds will form in the UGS, (2) the initiation phase, when prostatic buds begin to form, and (3) the elongation phase, when proliferation, cell adhesion, and cell migration coordinate outgrowth of prostatic buds into UGM. Timing of prostatic bud formation and the quantity and pattern of buds that are formed in the UGS are strictly regulated [3, 4]. The position of prostatic buds as they emerge from the UGS in utero determines the arrangement of prostate ducts in adulthood.[PMID:18977204] prostate ductal progenitor UBERON:0003820 prostate primordium prostatic bud EMAPA:36141 prostate gland bud urogenital sinus epithelium epithelial bud prostate field