Lower Urinary Tract

Early Genitourinary System

Male Reproductive System

Female Reproductive System



Organ Summary - Early Genitourinary System

Early urogenital system

Early Genitourinary System




Note: The above buttons only retrieve data for the Early Reproductive System - a subset of the Early Genitourinary System.

Development of the murine reproductive system

In the genital system, the first evidence of a genital (or gonadal) ridge is seen at about 10 dpc. This arises as a distinct, rostro-caudally elongated mound of tissue that develops on the medial aspect of the mesonephros. At this stage, and for approximately two days, it is not possible either histologically or morphologically to recognise whether the future gonad is destined to give rise to a testis, or to an ovary. For this reason, this period is referred to as the so-called “indifferent” gonad stage. Within a relatively short period of time, however, by about TS19 (11.5 dpc), there is considerable evidence of primordial germ cell colonization of the indifferent gonads. (more…)

Development of the murine kidneys

The metanephros develops from the most caudal part of the nephrogenic cord that is itself derived from the intermediate plate mesoderm (see above). The initial renal anlage that develops from the most rostral part of the nephrogenic cord is termed the pronephros. The latter is not believed to function in the mouse, or in any other mammal. However, within the pronephros, a relatively small number of pronephric (or nephrotomal) vesicles form in a cranio-caudal direction, and these “drain” into the pronephric duct. As the pronephros is a relatively transient structure in mammals, the absence of differentiated glomeruli within it strongly suggests that it probably does not act as even a primitive excretory organ. Despite the complete degeneration of the pronephros, the pronephric duct is retained. This structure is then taken over by the mesonephros (also termed the “Wolffian” body), and is only then termed the mesonephric portion of the nephric duct. (more…)


Early urogenital system (Theiler Stage 17)