title: Effect of 2-mercaptoethanol and cysteine supplementation during in vitro maturation on the developmental competence of oocytes from hormone-stimulated lambs.
abstract: The objective was to determine the effect of 2-mercaptoethanol and cysteine on in vitro developmental competence of oocytes from lambs (4-8-week old) stimulated with eCG and pFSH. Oocytes were matured in medium (TCM199) with no supplement (Control group) or with 100 microM 2-mercaptoethanol and 600 microM cysteine (GSH group). Oocytes from adult sheep were also included (Adult group). The addition of 2-mercaptoethanol and cysteine did not improve nuclear maturation or microtubule configuration 12, 15, 18, or 24 h after placement in maturation medium. Sperm head decondensation and male pronucleus formation were evaluated at 6, 12, and 18 h after commencement of IVF; sperm decondensation appeared earlier in the GSH group (6h after the start of IVF). There were differences (P<0.05) between the Control group and the GSH and Adult groups for: fertilization rate at both 12 h (55.4, 77.0, and 80.6%, respectively) and 18 h (67.9, 86.9, and 88.7%); parthenogenesis rate at both 12 h (25.0, 10.8, and 5.6%) and 18 h (28.3, 9.8, and 4.5%); and polyspermy rate at 18 h (26.4, 4.9, and 5.7%). Blastocyst rate at 7d was higher in the GSH group than the Control group (23.9% vs. 14.9%, P<0.05), but both were lower (P<0.05) than the Adult group (38.3%). The addition of 2-mercaptoethanol and cysteine improved sperm decondensation and rates of fertilization and the blastocyst development to 7d, with no effect on blastocyst rate at 9 d.
authors.affiliation: State Key Laboratory for Agrobiotechnology and Department of Animal Physiology, College of Biological Science, China Agricultural University, Beijing 100094, China.
authors.forename: J
authors.initials: J
authors.lastname: Bai
authors.forename: J
authors.initials: J
authors.lastname: Hou
authors.forename: H
authors.initials: H
authors.lastname: Guan
authors.forename: F
authors.initials: F
authors.lastname: Yan
authors.forename: X
authors.initials: X
authors.lastname: Cui
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: An
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D003470:Culture Media; D003545:Cysteine / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D008623:Mercaptoethanol / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects*; D010053:Ovary / Q000187:drug effects; D012756:Sheep
chemical_list: D006063:Chorionic Gonadotropin; D003470:Culture Media; D008623:Mercaptoethanol; D005640:Follicle Stimulating Hormone; D003545:Cysteine