Expression and Regulation of FGF Receptors in Mouse Granulosa Cells

Abstract

Signals from fibroblast growth factors (FGFs) play a critical role in regulating the development of ovarian granulosa cells; however, the expression and regulation of FGF receptors are not well understood. The present study was conducted to assess the expression kinetics of transcripts encoding FGF receptors (FGFRs) during granulosa cell development in mice. In addition, the effects of oocytes on the levels of Fgfr transcripts were examined, as well as the expression of FGFR mRNA expression in porcine granulosa cells. All four types of Fgfr transcripts were detected in cumulus and mural granulosa cells with a tendency toward higher expression levels in mural granulosa cells. Interestingly, the expressions of Fgfr1 and Fgfr2 mRNA in cumulus cells were suppressed by co-culture with oocytes, whereas their expression in mural granulosa cells was promoted. Porcine cumulus cells expressed higher levels of FGFR1 and FGFR2 mRNA than mural granulosa cells. The results show that FGF receptor expression in granulosa cells, at least at the mRNA level, is dynamically regulated during follicular development, and that oocytes participate in the regulation of differential expression between cumulus and mural granulosa cells. Moreover, the regulation of transcripts encoding FGF receptors in granulosa cells may differ between mice and pigs.