title: Effect of low oxygen tension atmosphere and maturation media supplementation on nuclear maturation, cortical granules migration and sperm penetration in swine in vitro fertilization.
abstract: The aim of this study was to evaluate the efficiency of low oxygen tension (5% CO(2) , 5% O(2) and 90% N(2) ) on in vitro oocyte maturation using defined media (0.1% polyvinyl alcohol - PVA) or 10% porcine follicular fluid (PFF)-supplemented media. To achieve this goal, oocytes were evaluated regarding cortical granules (GCs) migration, nuclear maturation and sperm penetration. Oocytes were in vitro matured under different conditions: 5% or 20% O(2) atmosphere and 0.1% PVA- or 10% PFF-supplemented media and evaluated at 0 and 44 h of maturation. To evaluate the migration of CGs and nuclear maturation, by confocal microscopy, oocytes were incubated with 100 μg of FITC-PNA/ml and 10 μg/ml of propidium iodide. To address sperm penetration, after maturation, in vitro fertilization for 6 h and in vitro culture for 18 h, zygotes were incubated with 10 mg/ml Hoechst 33342. Pronuclei and polar bodies were quantified using an epifluorescence microscope. Atmosphere conditions did not affect the CGs migration, but media supplementation did. Oocytes matured in 10% PFF media had a higher percentage of CGs in the oocyte periphery than oocytes matured in PVA-supplemented media. However, this fact did not have effect on in vitro sperm penetration levels. No effect of atmosphere conditions and media supplementation was observed on the rates of metaphase II oocytes. Therefore, the use of low oxygen tension in association with PVA maturation media does not improve the in vitro maturation system of porcine oocytes, because its use did not improve nuclear maturation, CGs migration and zygotes monospermic rates.
authors.affiliation: EMBRAPA Swine and Poultry Research Center, Concordia, Santa Catarina, Brazil. mariana.marques@cnpsa.embrapa.br
authors.forename: M G
authors.initials: MG
authors.lastname: Marques
authors.forename: F R O
authors.initials: FR
authors.lastname: de Barros
authors.forename: M D
authors.initials: MD
authors.lastname: Goissis
authors.forename: P V
authors.initials: PV
authors.lastname: Cavalcanti
authors.forename: C H C
authors.initials: CH
authors.lastname: Viana
authors.forename: M E O D
authors.initials: ME
authors.lastname: Assumpção
authors.forename: J A
authors.initials: JA
authors.lastname: Visintin
mesh_terms: D000818:Animals; D003470:Culture Media / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary*; D008297:Male; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010100:Oxygen / Q000494:pharmacology*; D013084:Sperm-Ovum Interactions / Q000187:drug effects*; D013552:Swine / Q000502:physiology*
chemical_list: D003470:Culture Media; D010100:Oxygen