Get access

Protein Localization of Epidermal Growth Factor in Sheep Ovaries and Improvement of Follicle Survival and Antrum Formation In Vitro

Authors

  • LP Santos,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • VRP Barros,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • AYP Cavalcante,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • VG Menezes,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • TJS Macedo,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • JMS Santos,

    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • VR Araújo,

    1. LAMOFOPA, Faculty of Veterinary Medicine, State University of Ceara, Fortaleza, CE, Brazil
    Search for more papers by this author
  • MAA Queiroz,

    1. Laboratory of Bromatology and Animal Nutrition, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    Search for more papers by this author
  • MHT Matos

    Corresponding author
    1. Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil
    • Author's address (for correspondence): MHT Matos, Curso de Pós-Graduação em Ciência Animal (CPGCA), Universidade Federal do Vale do São Francisco (UNIVASF), Rodovia BR 407, Km 12, Lote 543, Projeto de Irrigação Nilo Coelho, S/N, C1, CEP: 56300-990, Petrolina, PE, Brasil.

      E-mail: helena.matos@univasf.edu.br

    Search for more papers by this author

Contents

The aims of this study were to characterize EGF protein expression in ovine ovaries and to verify the effect of EGF on the in vitro development of isolated pre-antral follicles. After collection, ovarian tissue was fixed for immunohistochemical analysis. Additional pairs of ovaries were collected, and secondary follicles were cultured for 18 days in α-MEM+ (control) alone or supplemented with EGF (1, 10 or 50 ng/ml). The immunostaining for EGF was observed in oocytes from pre-antral and antral follicles, in granulosa cells of primary and secondary follicles, as well as in cumulus and mural cells of antral follicles. After 18 days, the results showed that treatment with 50 ng/ml EGF significantly increased the percentage of morphologically normal follicles compared with the control group (α-MEM+) and significantly reduced the precocious extrusion of oocytes and increased the percentage of antral follicles compared with the control and 1 ng/ml EGF. All the treatments induced a progressive and significant increase of the follicular diameter throughout the period of culture. However, there were no significant differences in follicular diameter or in the daily growth rate among treatments. In conclusion, this study demonstrated the presence of EGF in ovine ovaries. Moreover, 50 ng/ml EGF increased the percentage of normal follicles and improved antrum formation in isolated ovine follicles after 18 days of in vitro culture.

Ancillary