Effect of mesenchymal glandular inductors on the growth and cytodifferentiation of neonatal mouse seminal vesicle epithelium.

To investigate the developmental properties of glandular mesenchymal inductors along the cranial-caudal extent of the developing male urogenital tract, neonatal mouse seminal vesicle epithelium (SVE) was combined with mesenchyme of the seminal vesicle (SVM), urogenital sinus (UGM), bulbourethral gland (BUG-M), or bladder (BLM) and grafted under the renal capsule of adult syngeneic or athymic male mice. Both SVM + SVE and UGM + SVE tissue recombinants expressed SV histogenesis and SV secretory proteins. BUG-M + SVE recombinants exhibited extensive growth as evidenced by a 36-fold increase in wet weight and a 27-fold increase in DNA content; however, the glandular structures that were induced in the SVE lacked the convoluted mucosa typical of SV. Furthermore, neither SV nor prostatic secretory proteins were detected in these recombinants. SVE grown in association with BLM failed to develop altogether. Thus, the ability to promote SV histogenesis and function is distinctly different in mesenchyme of cranial (SVM and UGM) versus caudal (BUG-M) regions. This implies the existence of a glandular inductive field in the developing male urogenital tract within which inductive activity varies regionally.