Improving postcryopreservation survival capacity: an embryo-focused approach

ABSTRACT

The major challenge for a greater dissemination of in vitro produced (IVP) bovine embryos is to improve embryonic survival after cryoprese rvation. The involvement of embryo niclipids on this issue is well documented. However, it has been recognized that not only the amount of lipids that affects embryo cryotolerance, but the embryo survival capacity after cryopreservation is a rather multifactorial event. In this review, some strategies to improve embryonic lipid composition and postcryo preservation survival by modifying the embryos themselves to make them more cryopreservable are overviewed The ue of sedefined and defined serum free cul ture media, the addition of some chemicals in the culture media to modify embryo lipid composition, and the modulation of embryo cell membrane fluidity by cholesterol or unsaturated fatty acids added to the culture media and oocyte/embryo donor nutritional management with a diet enriched in polyunsaturated fatty acids, were described as alternatives for the improvement of IVP embryo survival after cryopreservation.