The morphogenetic tissue interactions between epithelium and mesenchyme of male accessory sexual gland primordia were investigated by standard culture methods. Seminal vesicle (SV), urogenital sinus (UGS), and preputial gland (PP) rudiments were excised from 13- to 19-day old embryonic mice. After tryptic-separation, the epithelium and mesenchyme of these rudiments were recombined into control (homotypic) and experimental (heterotypic) recombinants which were subsequently grown in the anterior chamber of the eye of adult male hosts.
In recombinants composed of accessory sexual gland epithelium (SV, UGS, or PP) and urogenital gland mesenchyme (SV or UGS), the histotypic pattern of the recombinants reflected the source of the epithelium. Normal differentiation of SV, UGS, and PP epithelium occurred consistently when these epithelia were associated with SV or UGS mesenchyme. On the other hand, urogenital gland epithelium (SV or UGS) did not develop normally when associated with the integumentally-derived preputial gland mesenchyme. Instead, seminal vesicle epithelium was maintained as a columnar epithelium arranged in a simple tubular structure, while urogenital sinus epithelium formed a keratinized epithelium despite the presence of androgens. These data illustrate (1) the supportive properties common to urogenital mesenchyme, (2) the stability of accessory sexual gland epithelium, and (3) the lack of strict mesenchymal requirements of these epithelia. Furthermore, the data suggest that urogenital and integumental mesenchyme differ significantly in their ability to mediate hormonally-dependent developmental processes.