Maturation, fertilization, and development of dog oocytes in vitro.
Preovulatory oocytes were collected from ovaries of beagle bitches that had received superovulatory treatment. They were cultured in a modified Krebs-Ringer bicarbonate solution containing 10% fetal calf serum and 30 mg/L gentamicin sulfate for up to 72 h. About 32% of oocytes reached metaphase II by 72 h of culture. When these in vitro-matured oocytes were inseminated with ejaculated beagle spermatozoa that had been preincubated for 4 h, sperm penetration of the zona pellucida started about 1 h after insemination, and both male and female pronuclei were seen in the ooplasm at 8 h after insemination. At 18-20 h after insemination, oocytes were transferred to Whitten's medium and cultured for 76-78 h. The first cleavage was observed at 48 h after insemination, and 15 of 45 oocytes developed to the 2-8-cell stage. These results demonstrate that in vitro-matured canine oocytes can be fertilized and develop to the 8-cell stage in vitro.
Yamada
S
S
Second Research Division, Fuji Life Science Inc., Yamanashi-pref., Japan.
Shimazu
Y
Y
Kawaji
H
H
Nakazawa
M
M
Naito
K
K
Toyoda
Y
Y
D000818:Animals; D002454:Cell Differentiation; D004285:Dogs; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D066298:In Vitro Techniques; D008297:Male; D009865:Oocytes / Q000166:cytology*; D010062:Ovulation Induction; D013075:Sperm Capacitation