The Effects Of CLC On The Quality And Sperm-egg Binding Of GV Stage Frozen-thawed Porcine Oocytes

Cryopreservation of oocytes is a potentially valuable technology and one of the most developed studies in the field of assisted reproduction.Cryopreservation and in vitro culture of porcine oocytes have great medical value for embryonic stem cell research,but at present,the in vitro culture and embryo production of porcine oocytes after freezing and thawing are still backward,probably due to the low temperature during cryopreservation.The freezing damage caused by the oocyte affects the quality of the oocyte.The main purpose of this experiment is to investigate whether the addition of the cryoprotectant CLC(methyl-?-cyclodextrin)to the vitrification of frozen chilled porcine GV oocytes maturation rate,zona pellucida lysis time,apoptosis protein The amount of expression and the combination of spermatozoa have an effect.The GV stage oocytes after freezing and thawing were tested for in vitro maturation,heat-clearing with zona pellucida,and Western blotting(WB)to determine the quality of pig oocytes.Routine testing of fresh pig semen is an important process to aid in the detection of sperm-egg binding.The blank control group with 0 mg/ml CLC was set,and the treatment group with 0.5 mg/ml,5 mg/ml,and 10 mg/ml CLC were added.The GV stage oocytes were cryopreserved for two weeks for in vitro maturation andculture.The results showed that:1.The oocyte maturation rate was the highest at the concentration of 5 mg/ml CLC(74.67 4.67%),which was significantly higher than that of the control group(P<0.05).When the concentration of 5 mg/ml CLC was added,the zona pellucidum hardening time was the shortest,which was significantly lower than that of the control group(P<0.05).2.Cleaved caspase-3 protein expression was lowest when CLC was added at 5 mg/ml.3.In the sperm adhesion test,the adhesion rate of sperm and oocyte in the treatment group with different concentrations was higher than that in the control group.Through experiments,the addition of cryoprotector CLC(methyl--cyclodextrin)in vitrified freezing solution can reduce the low temperature damage of pig oocytes during cryopreservation,protect the quality of oocytes and improve the sperm-egg binding ability.