title: Effect of estradiol-17β during in vitro growth culture on the growth, maturation, cumulus expansion and development of porcine oocytes from early antral follicles.
abstract: Growing porcine oocytes from early antral follicles can acquire meiotic and developmental competence under suitable culture conditions, but at lower rates compared to full-grown oocytes. We postulated that estradiol-17β (E2 ) supported the acquisition of meiotic and developmental competence as well as cumulus-expansion ability during growth culture. Growing oocytes from early antral follicles (1.2 to 1.5 mm in diameter) were grown in vitro for 5 days in a medium containing 0, 10(-7) , 10(-6) , 10(-5) or 10(-4)  mol/L E2 ; after in vitro maturation, 35, 58, 47, 74 and 49% of oocytes matured to metaphase II, 25, 79, 77, 90 and 97% acquired cumulus-expansion ability, and 23, 54, 63, 89 and 64% were fully surrounded by cumulus cells, respectively. Following maturation, electro-stimulation was applied to the oocytes grown with 10(-5)  mol/L E2 . After 6 days of culture, in vitro-grown oocytes developed to the blastocyst stage at a rate similar to that for full-grown oocytes (31% and 40%, respectively). Therefore, we suggest that the use of E2 during growth culture improves the meiotic and developmental competence of oocytes, cumulus-expansion ability, and cumulus cell attachment to the oocytes.
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kubo
authors.forename: Ilse Silvia
authors.initials: IS
authors.lastname: Cayo-Colca
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyano
mesh_terms: D000818:Animals; D001755:Blastocyst; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000502:physiology*; D004558:Electric Stimulation; D004958:Estradiol / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D008540:Meiosis / Q000187:drug effects*; D008677:Metaphase / Q000187:drug effects; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects; D006080:Ovarian Follicle / Q000166:cytology*; D013552:Swine
chemical_list: D004958:Estradiol
keywords: blastocyst; electro-stimulation; estradiol-17β; in vitro growth; porcine oocyte