Figure 1.

Two stereo pair images (convergent, or cross-eyed viewing) of computer-assisted, serial-section reconstructions showing the dorsal portion of the prostate from two mouse fetuses. The prostate from a control male with 0.21 pg/ml free serum estradiol (blue urethra) is shown below. The top prostate is reconstructed from a male fetus exposed to 0.32 pg/ml free serum estradiol (red urethra). Glandular buds that form into the dorsal (green), lateral (yellow), and dorsocranial (blue) glands in the adult prostate can be seen as outgrowths of the fetal urogenital sinus (ventral buds are not visible). The utriculus (pink) is the remnant of the regressing embryonic female reproductive tract (Müllerian ducts). Compared with controls, estradiol significantly increased the number of prostatic glandular buds and caused a reduction in the size of the lumen of the urethra, which passes through the prostate.