The development of the male genitourinary system: III. The formation of the spongiose and glandar urethra

Area of Science:

• Embryology
• Urology
• Developmental Biology

Background:

• The formation of the urethra is traditionally explained by the disintegration of the urethral plate into a groove, followed by fusion of flanking urethral folds.
• Recent challenges question the existence of these folds, impacting the understanding of hypospadias, a condition linked to failed fold fusion.

Purpose of the Study:

• To investigate the role of mesodermal fold formation and fusion in urethral tube development.
• To clarify the embryological basis of congenital urethral abnormalities.

Main Methods:

• Histological examination of developing urethras.
• Analysis of mesodermal fold dynamics during embryonic development.

Main Results:

• Evidence supports the essential role of mesodermal fold formation and subepithelial fusion in creating the urethral tube.
• The process of fold fusion is critical for normal urethral development.

Conclusions:

• Mesodermal fold formation and fusion are fundamental to urethral tube development.
• Disruptions in this process provide a clear explanation for common congenital urethral abnormalities, including hypospadias.