title: Protein localization of epidermal growth factor in sheep ovaries and improvement of follicle survival and antrum formation in vitro.
abstract: 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.
authors.affiliation: Nucleus of Biotechnology Applied to Ovarian Follicle Development, Federal University of San Francisco Valley, Petrolina, PE, Brazil.
authors.forename: L P
authors.initials: LP
authors.lastname: Santos
authors.forename: V R P
authors.initials: VR
authors.lastname: Barros
authors.forename: A Y P
authors.initials: AY
authors.lastname: Cavalcante
authors.forename: V G
authors.initials: VG
authors.lastname: Menezes
authors.forename: T J S
authors.initials: TJ
authors.lastname: Macedo
authors.forename: J M S
authors.initials: JM
authors.lastname: Santos
authors.forename: V R
authors.initials: VR
authors.lastname: Araújo
authors.forename: M A A
authors.initials: MA
authors.lastname: Queiroz
authors.forename: M H T
authors.initials: MH
authors.lastname: Matos
mesh_terms: D000818:Animals; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D010053:Ovary / Q000166:cytology* / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*; D012756:Sheep / Q000502:physiology*
chemical_list: D004815:Epidermal Growth Factor