Pishko O. Osmotic behavior of mouse oocytes and embryos at the different steps of cryopreservation

The thesis is aimed to study the osmotic behavior of mouse oocytes and embryos at different steps of cryopreservation and to determie the transport parameters of cells. The development stage has been shown not affecting significantly the permeability coefficient for water molecules via embryo plasma membranes. There are no statistically significant differences for coefficients of membrane permeability for one- and two-cell embryos for ethylene glycol molecules (measured in 10% ethylene glycol solutions) and only for 8-cell embryo the tendency to a reduction of this index is observed. It has been established that fertilization and stage of development do not affect permeability coefficient of plasma membranes of mouse embryos for molecules of 1,2-PD within the limits of first three cleavage steps. The use of ethylene-sucrose cryopreservation medium for freezing the two-cell mouse embryos, being sensitive to the effect of cryodamage was substantiated.