Preliminary Study On The Effect Of Vitrification On Early Embryo Development In Porcine

In order to explore the minimum toxicity of porcine embryos on different split times and frozen protective liquid formula with the optimal frozen effect,the frozen method that was suitable for porcine embryos in different split times was sought to explore the impact of vitrification on developmental capacity of porcine embryos in different split times,so as to provide theoretical support for using frozen porcine embryos in productive practice.As a result,embryonic cells in three different split times were used as test materials.Vitrification was applied to screen out three different groups of frozen protective liquids.The effect differences of three different frozen carrier frozen embryos were compared.Also,parthenogenetic activation and external fertilization were selected to compare with developmental potential after embryo freezing-anabiosis.The findings showed that:1.Three frozen protective liquids had the low toxic role on embryonic cells in different split times.Embryonic survival rate,split rate,and blastocyst rate in each group were lower than the contrast group.Exclusive use of glycol or glycol mixing with dimethyl were suitable for vitrification of embryonic cells.By considering the effect of three frozen protective liquids on each period of embryos,the best frozen protective liquid was the second group:HM+7.5%(DMSO + EG),HM + 17%(DMSO + EG)+ 0.4 MSu.The best frozen period was the embryo 2nd cell period.2.The most suitable frozen protective liquids for embryonic cells with different split times were selected.GMP,OPS and hemi-straw carriers were used to compare with the impact on embryonic refrigeration,finding that OPS method was used in the 2nd cell period.The normal.rate of form was significantly higher than hemistraw and GMP tube(81.57%VS 58.96%VS 54.26%,P<0.05).The hemi straw had the highest split rate.In three methods,blastocyst rate didn’t have the significant difference,but hemi straw had the maximum blastocyst rate and blastocyst cell number.OPS method was applied in the 4th cell period.The normal rate of the form was significantly higher than other hemi straw and GMP tube(76.73%VS 34.24%VS 43.32%,P<0.05).Three carriers had no obvious difference in the split rate,but other hemi straw was slightly superior to other two carriers.Blastocyst rate hemi straw was higher than OPS and GMP tube(3.25%VS 0.49%VS 0,P<0.05).OPS method was applied in the 8th cell period.The normal rate of the form was significantly higher than other hemi straw and GMP tube(56.68%VS 26.58%VS 36.22%,P<0.05).Three carriers had no obvious difference in split rate.Blastocyst rate of hemi straw was higher than OPS and GMP(1.96%VS 0 VS 0,P<0.05).To sum up,hemi straw was more suitable for vitrification of embryos.3.Before vitrification,CB liquid was used to incubate embryonic cells in different split times,finding that survival rate and split rate of the embryo 2nd cell obtained by CB liquid incubation treatment and conventional vitrification had no statistical difference.Blastocyst rate of CB method was higher than the conventional vitrification(67.63%VS 54.14%,P<0.05).For the embryo 4th cell,survival rate disposed by CB method was higher than the conventional vitrification(52.47%VS 37.88%,P<0.05).Split rate and blastocyst rate didn’t have the significant difference,but the CB method was slightly higher than the conventional vitrification.For the embryo 8th cell,both methods had no statistical difference in survival rate,split rate and blastocyst rate.The findings indicated that the CB method was superior to the conventional vitrification.4.Parthenogenetic activation and in vitro fertilization(IVF)were used to compare with the developmental capacity of embryonic cells in different split times,finding that during the embryo 2nd cell,IVF and parthenogenetic activation had no significant difference in survival rate,split rate and blastocyst rate,but IVF was slightly superior to parthenogenetic activation.In the embryo 4th cell,survival rate of IVF was significantly higher than parthenogenetic activation(76.48%VS 52.47%,P<0.05).Both of them had no statistical difference in split rate and blastocyst rate.In the embryo 8th cell,survival rate and split rate of IVF were significantly higher than parthenogenetic activation(49.55%VS18.96%,P<0.05).IVF and parthenogenetic activation had no statistical difference in blastocyst rate.The findings indicated that embryonic cells’ early embryonic development rate disposed by IVF after frozen anabasis was superior to parthenogenetic activation.