title: Modification of maturation condition improves oocyte maturation and in vitro development of somatic cell nuclear transfer pig embryos.
abstract: This study examined effects on the developmental competence of pig oocytes after somatic cell nuclear transfer (SCNT) or parthenogenetic activation (PA) of : 1) co-culturing of oocytes with follicular shell pieces (FSP) during in vitro maturation (IVM); 2) different durations of maturation; and 3) defined maturation medium supplemented with polyvinyl alcohol (PVA; control), pig follicular fluid (pFF), cysteamine (CYS), or beta-mercaptoethanol (beta-ME). The proportion of metaphase II oocytes was increased (p < 0.05) by co-culturing with FSP compared to control oocytes (98% vs. 94%). However, blastocyst formation after SCNT was not improved by FSP coculture (9% vs. 12%). Nuclear maturation of oocytes matured for 39 or 42 h was higher (p < 0.05) than that of oocytes matured for 36 h (95-96% vs. 79%). Cleavage (83%) and blastocyst formation (26%) were significantly higher (p < 0.05) in oocytes matured for 42 h than in other groups. Supplementation of a defined maturation medium with 100 microM CYS or 100 microM beta-ME showed no stimulatory effect on oocyte maturation, embryo cleavage, or blastocyst formation after PA. beta-ME treatment during IVM decreased embryo cleavage after SCNT compared to pFF or PVA treatments, but no significant difference was found in blastocyst formation (7-16%) among the four treatment groups. The results indicated that maturation of oocytes for 42 h was beneficial for the development of SCNT embryos. Furthermore, the defined maturation system used in this study could support in vitro development of PA or SCNT embryos.
authors.affiliation: College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
authors.forename: Kilyoung
authors.initials: K
authors.lastname: Song
authors.forename: Eunsong
authors.initials: E
authors.lastname: Lee
mesh_terms: D000818:Animals; D003543:Cysteamine; D046149:Embryo Culture Techniques / Q000662:veterinary*; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D015571:Follicular Fluid; D008623:Mercaptoethanol; D053652:Nuclear Transfer Techniques / Q000662:veterinary*; D009865:Oocytes / Q000254:growth & development*; D034421:Sus scrofa / Q000502:physiology*; D013997:Time Factors
chemical_list: D003543:Cysteamine; D008623:Mercaptoethanol