Influence of BMP-2 on early follicular development and mRNA expression of oocyte specific genes in bovine preantral follicles cultured in vitro
Rodrigo O.D.S. Rossi1, Ellen V. da Cunha1, Antonia M.L.R. Portela1, José R.S. Passos1, José J.N. Costa1, Anderson W.B. Silva1, Márcia V.A. Saraiva1, Christina A. Peixoto2, Mariana A.M. Donato2, Robert van den Hurk3 and José R.V. Silva1
1Biotechnology Nucleus of Sobral - NUBIS, Federal University of Ceara, Sobral, CE, Brazil, 2Laboratory of Ultrastructure, CPqAM/FIOCRUZ, Federal University of Pernambuco, Recife-PE, Brazil and 3Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
Offprint requests to: José R.V. Silva, Biotechnology Nucleus of Sobral, NUBIS, Federal University of Ceara, Sobral, CE, Brazil. e-mail: jrvsilva@ufc.br or roberto_viana@yahoo.com
Summary. This study evaluates the effect of different concentrations (0, 10, 50 and 100ng/mL) of bone morphogenetic protein-2 (BMP-2) on primordial and secondary follicle development. It also investigates the effects of FSH and BMP-2 on the growth, morphology, ultrastructure and expression of mRNA for GDF9, NLRP5 and NPM2 genes in secondary follicles cultured for 18 days. The presence of BMP-2 at all tested concentrations increased the development of primordial follicles in vitro, but the highest concentration of BMP-2 (100 ng/mL) reduced the percentage of normal follicles when compared with tissues cultured with 10 ng/mL BMP-2. During culture of secondary follicles, in contrast to higher concentrations (50 or 100 ng/mL), 10 ng/mL BMP-2 kept the morphology of follicles during initial stages of in vitro culture. This concentration of BMP-2 also benefits maintenance of the ultrastructure of 18-day cultured follicles. The presence of both BMP-2 and FSH in culture medium resulted in a significant (P<0.05) increase in follicular diameter after 18 days of culture. However, both FSH and BMP-2 reduced follicular mRNA expression of GDF9 and NLRP5 when compared to follicles cultured in media containing only FSH. In combination with FSH, BMP-2 reduced the mRNA levels of NPM2, when compared to follicles cultured in control medium. It is concluded from these data that 10 ng/mL BMP-2 promotes the growth of primordial in vitro and it helps to maintain the ultrastructure of secondary follicles, while FSH is more important for better expression of follicular markers like GDF9 and NLRP5. Histol Histopathol 31, 339-348 (2016)
Key words: Ovarian follicles, BMP-2, FSH, Cow, Culture
DOI: 10.14670/HH-11-674