Factors affecting survival rates of in vitro produced bovine embryos after vitrification and direct in-straw rehydration

摘要: The aim of this work was to investigate the possibilities simplification, and outline limits application, a vitrification method for cow embryos. Morulae blastocysts were produced by in vitro fertilization slaughterhouse-derived, matured oocytes with frozen-thawed bull semen, subsequent culture on granulosa cell monolayer. Vitrification performed equilibration embryos 12.5% ethylene glycol dimethylsulphoxide at 20-22 degrees C 60 s, then 25% 4 another s. Embryos loaded straws, placed liquid nitrogen vapour 2 min, plunged. Straws thawed 22 water-bath, directly rehydrated further incubated straw, expelled cultured 72 h. In first experiment, different age developmental stage (Day 5 compacted morulae, Day 6 early blastocysts, Days 7 expanded 8 hatched blastocysts) as well previously subjected partial zone dissection vitrified. After thawing, re-expansion rates zona-dissected did not differ (67 87%, respectively), hatching more frequent frozen advanced stages (34, 47 63% respectively). rate morulae lower (10%) no these observed. second vitrified using PBS, PBS+albumin, TCM199 TCM199+calf serum holding media. No differences seen. However, when incubation concentrated cryoprotectant solution C, embryo survival decreased (PBS+albumin) or survived (TCM199+calf serum) procedure. third vitrified, thawed, 1 day, re-expanded again thawed. Out 87% that cycle, 73% 47% following thawing. These observations prove procedure described is relatively harmless, it can be used an intact zona required obtain high rates.