TY - JOUR
T1 - The prostatic utricle is not a müllerian duct remnant
T2 - Immunohistochemical evidence for a distinct urogenital sinus origin
AU - Shapiro, Ellen
AU - Huang, Hongying
AU - McFadden, Deborah E.
AU - Masch, Rachel J.
AU - Ng, Eliza
AU - Lepor, Herbert
AU - Wu, Xue Ru
AU - Khoury, Antoine
PY - 2004/10
Y1 - 2004/10
N2 - Purpose: The embryological origin of the utricle is thought to be a remnant of the fused caudal ends of the müllerian ducts (MDs). Others propose that the urogenital sinus (UGS) contributes either partially or totally to the development of this structure. Using immunohistochemical probes, we provide strong evidence that the utricle is of UGS origin only. Materials and Methods: Human fetal prostates, gestational ages 9 to 24 weeks, were serially cross-sectioned. Representative sections were stained with antibodies to p63 (basal cell marker), vimentin (mesoderm marker), uroplakins (marker for urothelium) Pax-2 (expressed in ductal and mesenchyme of urogenital system including the MDs and wolffian ducts) and Ki67 (proliferation). Apoptosis was detected with the TUNEL assay. Results: By 9 weeks there was weak expression of p63 in the basal layer of the UGS. At 11 weeks there was increased staining of p63 in the UGS and some p63 staining of the fused MDs, which expressed Pax-2 at this time. At 14 to 15 weeks as the MDs were undergoing apoptosis, there was an ingrowth of uroplakin-expressing UGS epithelium into the periurethral stroma, which formed a plate of p63 positive cells just beneath the UGS that was Ki67 positive. The remaining caudal MD epithelium was p63 negative and expressed vimentin and Pax-2. By 17 weeks the plate of p63 positive cells elongated forming the utricle that remained p63 positive but Pax-2 and vimentin negative. Conclusions: We show that the utricle forms as an ingrowth of specialized cells from the dorsal wall of the UGS as the caudal MDs regress.
AB - Purpose: The embryological origin of the utricle is thought to be a remnant of the fused caudal ends of the müllerian ducts (MDs). Others propose that the urogenital sinus (UGS) contributes either partially or totally to the development of this structure. Using immunohistochemical probes, we provide strong evidence that the utricle is of UGS origin only. Materials and Methods: Human fetal prostates, gestational ages 9 to 24 weeks, were serially cross-sectioned. Representative sections were stained with antibodies to p63 (basal cell marker), vimentin (mesoderm marker), uroplakins (marker for urothelium) Pax-2 (expressed in ductal and mesenchyme of urogenital system including the MDs and wolffian ducts) and Ki67 (proliferation). Apoptosis was detected with the TUNEL assay. Results: By 9 weeks there was weak expression of p63 in the basal layer of the UGS. At 11 weeks there was increased staining of p63 in the UGS and some p63 staining of the fused MDs, which expressed Pax-2 at this time. At 14 to 15 weeks as the MDs were undergoing apoptosis, there was an ingrowth of uroplakin-expressing UGS epithelium into the periurethral stroma, which formed a plate of p63 positive cells just beneath the UGS that was Ki67 positive. The remaining caudal MD epithelium was p63 negative and expressed vimentin and Pax-2. By 17 weeks the plate of p63 positive cells elongated forming the utricle that remained p63 positive but Pax-2 and vimentin negative. Conclusions: We show that the utricle forms as an ingrowth of specialized cells from the dorsal wall of the UGS as the caudal MDs regress.
KW - Embryology
KW - Mullerian ducts
UR - http://www.scopus.com/inward/record.url?scp=4544350463&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4544350463&partnerID=8YFLogxK
U2 - 10.1097/01.ju.0000140267.46772.7d
DO - 10.1097/01.ju.0000140267.46772.7d
M3 - Article
C2 - 15371806
AN - SCOPUS:4544350463
VL - 172
SP - 1753
EP - 1756
JO - Investigative Urology
JF - Investigative Urology
SN - 0022-5347
IS - 4 II
ER -