Vitrification of bovine oocytes: implications of follicular size and sire on the rates of embryonic development.
OBJECTIVE
The objectives were to test how the source of oocytes and semen impacted vitrification of large numbers of bovine oocytes and subsequent IVF and early embryo development to test procedures that may assist with assisted reproductive technologies in humans.


METHODS
Bovine oocytes were vitrified from follicles of different diameters, small (< or =4 mm) and medium (4 to 10 mm), using nylon mesh. Oocytes were exposed to the cryoprotectant composed of 40% (v/v) ethylene glycol, 18% (w/v) Ficoll-70, and 0.3 M sucrose in three stepwise dilutions. Thawing was conducted with a series of 0.5, 0.25 and 0.125 M sucrose dilutions in 20% fetal bovine serum.


RESULTS
The cleavage (39.1% vs. 58.5%) and blastocyst rates (5.1% vs. 22.9%) were significantly lower for the vitrified oocytes. Follicle size had a significant impact on the development of embryos. Sires had significant effects on embryonic developmental rates.


CONCLUSIONS
We conclude that differences in development exist due to follicle source and sire used for IVF after vitrification.
Anchamparuthy
Vahida M
VM
Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0315, USA.
Dhali
Arindam
A
Lott
Whitney M
WM
Pearson
Ronald E
RE
Gwazdauskas
Francis C
FC
D000818:Animals; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D015925:Cryopreservation / Q000379:methods* / Q000592:standards; D003451:Cryoprotective Agents / Q000494:pharmacology; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008297:Male; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D018709:Statistics, Nonparametric
D003451:Cryoprotective Agents