Factors influencing the results of transfers of rabbit embryos stored at -196 degrees C.
Rabbit embryos at the 8-cell and morula stages were frozen and stored at -196 degrees C for 2-200 days. After thawing the embryos were examined for their viability in vitro and in vivo. In vitro, 62.5% of frozen 8-cell embryos and 81.4% of frozen morulae developed to blastocysts. In the control group of unfrozen embryos, 93.2% 8-cell embryos and 92.4% morulae developed to the blastocyst stage. Culture permitted a more reliable elimination of the embryos damaged during freezing and thawing. Embryos were transferred into the reproductive tracts of the recipients either directly after thawing or after 24 h in culture. Synchronous transfers of frozen rabbit embryos were not successful. After asynchronous transfers of morulae and blastocysts into the oviducts, implantation was 31.8% and 42.9%, respectively. After transfer of blastocysts into the uterine horns of the recipients, 47.6% embryos implanted.
D000818:Animals; D001755:Blastocyst; D010064:Embryo Implantation; D004624:Embryo Transfer; D004971:Estrus; D005187:Fallopian Tubes; D005260:Female; D005615:Freezing; D009028:Morula / Q000637:transplantation; D011247:Pregnancy; D011817:Rabbits; D014599:Uterus