TY - JOUR
T1 - Feasibility of a nylon-mesh holder for vitrification of bovine germinal vesicle oocytes in subsequent production of viable blastocysts
AU - Abe, Yasuyuki
AU - Hara, Kenshiro
AU - Matsumoto, Hiromichi
AU - Kobayashi, Jin
AU - Sasada, Hiroshi
AU - Ekwall, Hans
AU - Rodriguez-Martinez, Heriberto
AU - Sato, Eimei
PY - 2005/6/1
Y1 - 2005/6/1
N2 - To improve the feasibility of nylon-mesh holder for vitrification of bovine cumulus-oocytes complexes (GV-COCs) having germinal vesicle, this study was conducted to demonstrate effects of sugars and protocol of exposure in vitrification on subsequent in vitro maturation, ultrastructural changes, and in vitro development in bovine immature oocytes after cryopreservation using nylon mesh. Before vitrification, GV-COCs were exposed to the cryoproteciant, which was composed of 40% (v/v) ethylene glycol, 18% (w/v) Ficoll-70, and 0.3 M sucrose (EFS40) or 0.3 M trehalose (EFT40), either by single step or in a stepwise way. The maturation rates in the stepwise exposure with EFS40 or EFT40 were significantly higher (P < 0.05) compared with the corresponding rates in the single step. In the stepwise exposure, few abnormalities were observed compared with the single-step exposure, where most oocytes showed a highly vacuolated cytoplasm with many ruptured mitochondria. Cleavage rates in fertilized oocytes previously exposed stepwise to EFS40 or EFT40 were significantly higher than those exposed by the single-step procedure. The cleaved embryos derived from the stepwise exposure to EFS40 developed to blastocysts. After transfer of blastocysts derived from vitrified GV oocytes, a female calf was born. These results indicate that vitrification of large numbers of bovine GV-COCs using a nylon-mesh holder accompanied with stepwise exposure minimizes structural damage in organelles, resulting in yield of viable blastocysts following in vitro embryo production.
AB - To improve the feasibility of nylon-mesh holder for vitrification of bovine cumulus-oocytes complexes (GV-COCs) having germinal vesicle, this study was conducted to demonstrate effects of sugars and protocol of exposure in vitrification on subsequent in vitro maturation, ultrastructural changes, and in vitro development in bovine immature oocytes after cryopreservation using nylon mesh. Before vitrification, GV-COCs were exposed to the cryoproteciant, which was composed of 40% (v/v) ethylene glycol, 18% (w/v) Ficoll-70, and 0.3 M sucrose (EFS40) or 0.3 M trehalose (EFT40), either by single step or in a stepwise way. The maturation rates in the stepwise exposure with EFS40 or EFT40 were significantly higher (P < 0.05) compared with the corresponding rates in the single step. In the stepwise exposure, few abnormalities were observed compared with the single-step exposure, where most oocytes showed a highly vacuolated cytoplasm with many ruptured mitochondria. Cleavage rates in fertilized oocytes previously exposed stepwise to EFS40 or EFT40 were significantly higher than those exposed by the single-step procedure. The cleaved embryos derived from the stepwise exposure to EFS40 developed to blastocysts. After transfer of blastocysts derived from vitrified GV oocytes, a female calf was born. These results indicate that vitrification of large numbers of bovine GV-COCs using a nylon-mesh holder accompanied with stepwise exposure minimizes structural damage in organelles, resulting in yield of viable blastocysts following in vitro embryo production.
KW - Assisted reproductive technology
KW - Bovine
KW - Embryo
KW - GV oocytes
KW - Gamete biology
KW - Nylon mesh
KW - Oocyte development
KW - Ovum
KW - Vitrification
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UR - http://www.scopus.com/inward/citedby.url?scp=18844383986&partnerID=8YFLogxK
U2 - 10.1095/biolreprod.104.037051
DO - 10.1095/biolreprod.104.037051
M3 - Article
C2 - 15689537
AN - SCOPUS:18844383986
VL - 72
SP - 1416
EP - 1420
JO - Biology of Reproduction
JF - Biology of Reproduction
SN - 0006-3363
IS - 6
ER -