title: Accelerated growth of bovine preantral follicles in vitro after stimulation with both FSH and BMP-15 is accompanied by ultrastructural changes and increased atresia.
abstract: The objective of the present study was to determine the effects of bone morphogenetic protein (BMP)-15 and FSH on the growth, viability, and expression of mRNA for FSH (FSH-R) and BMP-15 (BMPR-IB and BMPR-II) receptors in cultured bovine secondary follicles. Secondary follicles were microdissected and cultured for 12 days in minimum essential medium-α alone or supplemented with BMP-15, sequential FSH, both BMP-15 and FSH, or BMP-15 from days 0 to 6, and FSH from days 7 to 12. Thereafter, the effect of these treatments on the follicular volume, viability, and antrum formation and the levels of mRNA for BMPR-IB, BMPR-II, and FSH-R were assessed. Compared with day 0, the follicles cultured with FSH or BMP-15, or both, had a significant and progressive increase in volume (P < 0.05). However, the follicles cultured for 12 days with both BMP-15 and FSH had the greatest volume and a greater rate of antrum formation than those in control medium, but results similar to those cultured with FSH (days 0 to 12) or BMP-15 (days 0 to 6) and FSH (days 7 to 12). Together with their accelerating effect on in vitro follicle growth, the combination of FSH and BMP-15 induced ultrastructural changes in the cultured follicles and increased atresia. However, adding either BMP-15 or FSH to the culture medium, not only promoted follicular growth and follicular antrum formation, but also maintained follicular viability during culture. Except for follicles cultured in minimal essential medium-α, the levels of mRNA for BMPR-IB were reduced, and the levels of mRNA for FSH-R were significantly greater in follicles cultured in medium supplemented with BMP-15. In conclusion, all in vitro follicle treatments supported growth of bovine preantral follicles; however, adding both BMP-15 and FSH to the culture medium (minimal essential medium-α) for 12 days provided the greatest stimulation. Furthermore, the viability and ultrastructural integrity of cultured follicles were only maintained when only BMP-15 or FSH was added to the culture medium.
authors.affiliation: Biotechnology Nucleus of Sobral (NUBIS), Federal University of Ceará, Sobral, Ceará, Brazil.
authors.forename: M J
authors.initials: MJ
authors.lastname: Passos
authors.forename: G L
authors.initials: GL
authors.lastname: Vasconcelos
authors.forename: A W B
authors.initials: AW
authors.lastname: Silva
authors.forename: I R
authors.initials: IR
authors.lastname: Brito
authors.forename: M V A
authors.initials: MV
authors.lastname: Saraiva
authors.forename: D M
authors.initials: DM
authors.lastname: Magalhães
authors.forename: J J N
authors.initials: JJ
authors.lastname: Costa
authors.forename: M A M
authors.initials: MA
authors.lastname: Donato
authors.forename: R P
authors.initials: RP
authors.lastname: Ribeiro
authors.forename: E V
authors.initials: EV
authors.lastname: Cunha
authors.forename: C A
authors.initials: CA
authors.lastname: Peixoto
authors.forename: C C
authors.initials: CC
authors.lastname: Campello
authors.forename: J R
authors.initials: JR
authors.lastname: Figueiredo
authors.forename: R
authors.initials: R
authors.lastname: van den Hurk
authors.forename: J R V
authors.initials: JR
authors.lastname: Silva
mesh_terms: D000818:Animals; D055430:Bone Morphogenetic Protein 15 / Q000494:pharmacology*; D052004:Bone Morphogenetic Protein Receptors / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D005496:Follicular Atresia / Q000187:drug effects*; D005786:Gene Expression Regulation; D006080:Ovarian Follicle / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism
chemical_list: D055430:Bone Morphogenetic Protein 15; D012333:RNA, Messenger; D011962:Receptors, FSH; D005640:Follicle Stimulating Hormone; D052004:Bone Morphogenetic Protein Receptors