Effects of BMP-7 and FSH on the development of goat preantral follicles and levels of mRNA for FSH-R, BMP-7 and BMP receptors after in-vitro culture

ABSTRACT

This study aimed to evaluate the effects of FSH and BMP - 7 on growth and on expression of FSH - R , BMP - 7 and BMP receptors in cultured secondary follicles. Goat secondary follicles (~200 μm) were isolated and cultured in vitro, with 5% CO 2 in air at 39°C, for 6 days in the presence of BMP - 7 (50 ng/m l ) supplemented or not with FSH (50 ng/m l ). Follicular diameter and the formation of the antrum were evaluated before and after culture. For each treatment, at the end of culture period, groups of 6 follicles were collected and, after extraction of total RNA and cDNA synthesis, the levels of mRNA for FSH - R, BMP - 7 and BMP receptors in cultured secondary follicles were quantified by real time PCR. The results showed that addition of BMP - 7 or F SH to culture medium stimulated growth of secondary follicles , while addition of both BMP - 7 and FSH was needed to significantly increase the percentage of follicles forming an antrum and the follicular levels of mRNA for both BMP - 7 and FSH - R. For BMP receptors, FSH reduced the levels of mRNA for BMPR - IA and BMP - RII in comparison with those follicles cultured in MEM alone and supplemented with BMP - 7, respectively. In conclusion , l ike FSH, BMP - 7 affect s in vitro growth of cultured secondary follicle s , but it stimulates antrum formation and expression of the mRNA ’s for BMP - 7 and FSH - R only in presence of both BMP - 7 and FSH . However, the levels of mRNA f or BMP - RIA and BMP - RII are reduced in follicles culture d in medium supplemented with FSH.