Cryopreservation of bovine somatic cell nuclear-transferred blastocysts: effect of developmental stage.
The effect of developmental stage on the survival of bovine somatic cell nuclear-transferred blastocysts after freezing and thawing was evaluated. We also investigated how freezing affects nuclear-transferred (NT) embryos and in vitro fertilized (IVF) bovine embryos. Advanced-stage bovine NT blastocysts survived freezing better than early-stage NT blastocysts (86 vs 14%). The trend was similar with IVF embryos (87 vs 30%). At the stages tested, there was no significant difference in the survivability of NT and IVF embryos from advanced (86 vs 87%) or early-stage blastocysts (14 vs 30%). The average survival rate did not differ between NT and IVF bovine embryos (50 vs 51%). The higher survival rate of advanced-stage blastocysts compared to early-stage blastocysts in NT and IVF bovine embryos might be due to their higher cell number. In NT (128 +/- 25 vs 53 +/- 20) and IVF (128 +/- 29 vs 75 +/- 22) groups, advanced-stage blastocysts contained a significantly higher total cell number than early-stage blastocysts. There was no difference in total cell number between advanced-stage NT and IVF blastocysts (128 +/- 25 vs 128 +/- 29), however, early-stage NT and IVF blastocysts (53 +/- 20 vs 75 +/- 22) differed significantly.
Amarnath
Dasari
D
Laboratory of Animal Reproduction, College of Agriculture, Kinki University, Nara, Japan.
Kato
Yoko
Y
Tsunoda
Yukio
Y
D000818:Animals; D001757:Blastomeres / Q000166:cytology / Q000502:physiology*; D002417:Cattle; D002470:Cell Survival; D015925:Cryopreservation; D019855:Ethylene Glycol; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008297:Male; D053652:Nuclear Transfer Techniques; D015044:Zona Pellucida
D019855:Ethylene Glycol