Effects of GDF-9 and FSH on mRNA Expression for FSH-R, GDF-9 and BMPs in in vitro Cultured Goat Preantral Follicles

The aim of the present study was to determine the role of GDF-9 and/or FSH on the growth and mRNA expression for FSH-R, GDF-9, and BMPs in goat secondary follicles after culture in vitro. Goat secondary follicles (similar to 200 mu m) were isolated and cultured for six days in minimum essential medium (MEM) supplemented with GDF-9 (200 ng/mL), FSH (50 ng/mL) or both. At the beginning and end of culture, the follicular diameter was evaluated and compared. The levels of mRNA for GDF-9, FSH-R and BMPs - 2, - 4, - 6, - 7 and - 15 in cultured follicles were quantified by real time PCR. The results showed that a significant increase of follicle diameter after six days when compared to day 0, but the presence of GDF-9 and FSH did not influence the follicular growth in comparison with those cultured in MEM. Real time PCR showed that GDF-9 down-regulated the levels of mRNA for BMPs - 2 and 15, while FSH either alone or in combination with GDF-9 did not affect the expression of GDF-9, FSH-R and BMPs. In conclusion, GDF-9 reduced the expression of BMP-2 and - 15 in caprine preantral follicles after their culture, but FSH either alone or in association with GDF-9 did not control the expression of GDF-9, FSH-R and BMPs.