title: Different hormonal requirements of pig oocyte-cumulus complexes during maturation in vitro.
abstract: Cytoplasmic maturation as determined by male pronuclear formation following fertilization in vitro was examined in pig oocytes cultured under different hormonal conditions during either the first or second 20 h period of in vitro maturation. Exposure to several combinations of pregnant mares' serum gonadotrophin (PMSG) (10 IU ml-1), hCG (10 IU ml-1) and oestradiol (1 microgram ml-1) for a second 20 h period following culture in a medium supplemented with these hormones for 20 h did not result in differences among treatment groups in maturation rates, penetration rates or polyspermy rates. However, supplementation with PMSG and oestradiol for the last 20 h of culture reduced male pronuclear formation rates significantly. When oocyte-cumulus complexes were cultured in hormone-free media for 20 h after culture in several combinations of supplemental hormones for the first 20 h period, germinal vesicle breakdown rates and maturation rates were lower in oocytes previously exposed to oestradiol alone or no hormonal supplements (68-70% and 45-49%, respectively) than in oocytes previously exposed to PMSG or hCG (89-99% and 71-89%, respectively). Exposure of oocytes to oestradiol alone also reduced the penetration rate (61%) compared with PMSG or hCG (86-99%). Supplementation of media with PMSG alone or together with other hormones increased the male pronuclear formation rate (63-72%) compared with supplementation with oestradiol (33%) or no hormonal supplements (32%). The concentration of oestradiol in maturation medium decreased at filtration (to 216.5 +/- 72.6 ng ml-1) before culture.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Animal Sciences, University of Missouri-Columbia 65211.
authors.forename: H
authors.initials: H
authors.lastname: Funahashi
authors.forename: T
authors.initials: T
authors.lastname: Cantley
authors.forename: B N
authors.initials: BN
authors.lastname: Day
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry; D003593:Cytoplasm / Q000502:physiology; D004958:Estradiol / Q000032:analysis / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D008297:Male; D008540:Meiosis / Q000187:drug effects*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D011374:Progesterone / Q000032:analysis; D013084:Sperm-Ovum Interactions / Q000502:physiology; D013552:Swine; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin; D003470:Culture Media; D006064:Gonadotropins, Equine; D011374:Progesterone; D004958:Estradiol