Higher survival rate of vitrified and thawed in vitro produced bovine blastocysts following culture in defined medium supplemented with beta-mercaptoethanol.
The present study was conducted to compare bovine embryo developmental quality, after culture in different defined culture media, up to blastocyst stage, and subsequently cultured in media supplemented with beta-mercaptoethanol (beta-ME) following blastocyst vitrification and thawing. In part one of this study, presumptive zygotes were randomly allocated into the following media: (1) CR1, (2) KSOM, (3) SOF, and (4) sequential KSOM-SOF. In the second part of the study, blastocysts derived from four different culture media were subjected to a solid surface vitrification (35% (v/v) ethylene glycol+0.5M Sucrose+5% (w/v) Polyvinylpyrrolidone (PVP), and tested for the effect of beta-ME on their post-vitrification survival. Following thawing, blastocysts were cultured with or without beta-ME. Culture medium had no effect on cleavage rates; however, a significantly greater number of zygotes cultured in KSOM, KSOM-SOF, or SOF developed to the 8-cell stage, compared with those cultured in CR1. A greater proportion of the zygotes cultured in SOF or KSOM-SOF reached blastocysts, than did those cultured in CR1 or KSOM. The use of sequential KSOM-SOF significantly increased total cell numbers of Day 7 expanded-blastocysts when compared to those cultured in CR1, KSOM, or SOF. Addition of beta-ME into culture media after vitrification and thawing improved blastocyst survival, hatching rates, and total cell numbers of blastocysts. In conclusion, supplementation of beta-ME into culture medium after vitrification and thawing significantly increased blastocyst survival, hatching rates, and their total cell numbers. These results suggest that vitrified IVF embryos should be thawed and briefly cultured in beta-ME medium prior to embryo transfer.
Nedambale
Tshimangadzo Lucky
TL
Connecticut Center for Regenerative Biology, University of Connecticut, 1392 Storrs Rd., U-4243, Storrs, CT 06269-4243, USA. nedambale@hotmail.com
Du
Fuliang
F
Yang
Xiangzhong
X
Tian
Xiuchun Cindy
XC
D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000502:physiology; D002417:Cattle; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003470:Culture Media; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary*; D004624:Embryo Transfer; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008623:Mercaptoethanol / Q000494:pharmacology*; D014022:Tissue Survival / Q000187:drug effects
D003470:Culture Media; D008623:Mercaptoethanol