Fibroblast growth factor-10: A stromal mediator of epithelial function in the ovine uterus

Fibroblast growth factor-10 (FGF-10) is a stromal-derived paracrine growth factor considered to be important during embryogenesis; however, its expres sion by cells in the female reproductive tract has not been investigated. T herefore, an ovine FGF-10 cDNA was cloned from an ovine endometrial cDNA li brary to investigate expression and potential paracrine characteristics of FGF-10 in the ovine uterus. The ovine FGF-10 cDNA encodes a protein of 213 amino acids and possesses an unusually long 5' untranslated region (UTR). I n situ hybridization demonstrated that ovine FGF-10 mRNA was expressed by e ndometrial stromal cells and by mesenchymal cells of the chorioallantoic pl acenta. The mRNA for FGF-7, a homologue of FGF-10, was localized in the tun ica muscularis of blood vessels in endometrium and myometrium. In contrast, FGF receptor 2IIIb, the high-affinity receptor for both FGF-10 and FGF-7, was expressed exclusively in luminal epithelium, glandular epithelium, and placental trophectoderm. The in vivo spatial expression pattern suggests th at FGF-10 is a novel endometrial stromal cell-derived mediator of uterine e pithelial and conceptus trophectodermal functions. The nonoverlapping spati al patterns of expression for FGF-10 and FGF-7 in ovine uterus and conceptu s suggest independent roles in uterine function and conceptus development.