SPECIES-SPECIFIC DETECTION OF GROWTH-FACTOR GENE-EXPRESSION IN DEVELOPING MURINE PROSTATIC TISSUE

The aim of the present study was to develop a method by which the expr ession of paracrine signaling molecules could be localized to either e pithelial or stromal cells of developing prostatic tissue. Heterospeci fic tissue recombinants composed of mouse urogenital epithelium (mouse UGE) plus rat urogenital mesenchyme (rat UCM) and the reciprocal tiss ue recombinants, rat urogenital epithelium (rat UGE) plus mouse urogen ital mesenchyme (mouse UGM), were grafted under the renal capsule in i ntact, athymic male mouse and rat hosts. After 2 wk of growth, RNA fro m the grafts was analyzed by species-specific reverse transcription-po lymerase chain reaction for the expression of the mRNA for the followi ng molecules: transforming growth factors beta 1, beta 3, and alpha; e pidermal growth factor; epidermal growth factor receptor; and keratino cyte growth factor. The species of expression of these growth factor a nd receptor gene products within the heterospecific tissue recombinant s was identified, allowing determination of the cell layer in which th e genes were expressed. Identification of the tissue-specific expressi on of the growth factor and growth factor receptor profiles of the epi thelium and mesenchyme of this in vivo model provides a basis for unde rstanding the autocrine and paracrine mediators of cell-cell interacti ons in prostatic development.