Efficiency of cryopreservation of embryos obtained in vitro culture

The possibility of long-term storage of embryos at low temperatures made it possible to significantly reduce the cost, simplify and increase the efficiency of using the world's best genetic resources by importing and exporting not animals, but embryos, served as a prerequisite for the creation and preservation of the gene pool of rare and endangered breeds, and introduced a planning element to the work on transplantation. The article presents the results of research on the effectiveness of cryopreservation of embryos obtained in vitro using standard cryopreservation methods used for freezing embryos in vivo. Thawing of embryos was carried out in accordance with the tasks set: to determine the level of preservation of embryos in vitro during cryopreservation in ethylene glycol and glycerin. During cryopreservation, the stage of development and the quality of embryos were taken into account. According to the analysis of the obtained data, cryopreser-vation of embryos obtained in vitro using traditional methods significantly reduces the viability of embryos after thawing compared to in vivo embryos. Thus, when using glycerol as a cryoprotector, the safety of embryos in General was 54.2-68.0%, when using ethylene glycol 56.6-62.1%, while in vivo embryos, as practice shows, remain suitable for transplantation after thawing in 98-100% of cases. When using ethylene glycol, the safety of embryos of excellent quality was 56.9%, and good 55.5%. Late blastocysts were preserved in 53.5% of cases, and expanded blastocysts in 60.0 %. When using glycerol, the safety of embryos at the late blastocyst stage was 4.7 PP. higher in comparison with expanded blastocysts, and embryos of excellent quality showed preservation by 25.3 p. p. higher, compared with embryos of good quality.

криоконсервация, криопротектор, глицерин, этиленгликоль, сохранность, выживаемость, бластоциста, качество, cryopreservation, cryoprotector, glycerin, ethylene glycol, safety, survival, blastocyst, quality

1. Hasler, J.F. The current status and future of commercial embryo transfer in cattle / J.F. Hasler //. Reprod. Sci. - 2003. Vol. 15. - P. 245-264.

2. Leibo, S. One-step-methods for direct non-surgycal transfer of frozen-thawed bovine embryos / S. Leibo // Theriogenology. - 1984. - Vol. 21. - P. 767-790.

3. Martino, M. The ginetics of chilling sausetivity of bovine oocytes cooled to non physiological temperftures / M. Martino, J. Roland, A. Nakagawa, S. Leibo // Theriogenology. - 1995. - Vol. 43. - P. 272-289.

4. Pollard, J.W. Comparative cryobiology ofin vitro and in vivo produced bovine embryos / J.W. Pollard, S.P. Leibo // Theriogenology. - 1993. - Vol. 30. - P. 287-317.

5. Sudano, M.J. Lipid content and apoptosis of in vitro-produced bovine embryos as determinants of susceptibility to vitrification / M.J. Sudano, D.M. Paschoal, S. Rascado Tda, L.C. Magalhaes, L.F. Crocomo // Theriogenology. - 2011. - Vol. 75. - P. 12111220.

6. Whitingham, D.G. Survival of mouse embryo frozen to -1960C and -2960C / D.G. Whitingham, S.P. Leibo, P. Mazur // Science. - 1972. - Vol. 178.- P. 411-414.