Full-term development of in vitro-matured, vitrified and fertilized bovine oocytes.
In vitro-matured bovine oocytes were vitrified in a mixture of 2 M-dimethyl sulphoxide (DMSO), 1 M-acetamide and 3 M-propylene glycol dissolved in mTCM199. After vitrification and thawing, the oocytes were exposed to 2-0.1M-sucrose solution in 1 or 12 steps to remove the cryoprotectants. Then the oocytes were fertilized in vitro and co-cultured with a monolayer of cumulus cells for 7 days. Nine of 88 inseminated oocytes developed to the blastocyst stage. Three blastocysts were transferred to 3 recipients, resulting in 2 pregnancies.
Hamano
S
S
Tokyo Bio-Technology Center, Livestock Improvement Association Inc., 3-21-10 Higashishinagawa, Shinagawa-ku, Tokyo 140, Japan.
Koikeda
A
A
Kuwayama
M
M
Nagai
T
T