| Sperm cryopreservation is one of the necessary means of artificial insemination technology,and the composition of the sperm cryoprotectant is crucial during the production process.Protein tyrosine phosphorylation is one of the indicators for determining whether sperm is capacitating.The ROS produced during sperm capacitation produce oxidative stress when ROS accumulate to a certain level.To prevent oxidative stress,reduce freezing damage to sperm or prevent premature sperm maturation,the addition of antioxidant supplements to cryoprotectants provides enhanced protection against potential ROS accumulation.The study found that crocin is an effective antioxidant with the ability to reduce lipid peroxidation,mitochondrial and lysosomal membrane damage,similar to protective agents.The purpose of this experiment was to investigate the effects of safflor as a cryoprotectant on the capacitation and quality of bovine sperm and the expression of related antioxidant genes and apoptotic genes.0,0.5,1,15,2 mM crocin was added to the sperm cryoprotectant and frozen for two weeks.After thawing,the spermatozoa CASA test,hypotonic swelling test,Coomassie stain test and CASA auxiliary instrument test were performed.The sperm motility index,the sperm morphology and exercise quality at 0.5 mM was not significantly different from the control group,but the effect was the best in the treatment group(P<0.05).The protein-yield after the frozen-thawed sperm was evaluated.The level of phosphorylation was 35kDa,and crocin(0.5mM)was the highest level of tyrosine phosphorylation(P<0.05),but it was not significantly different from the control group;among the related antioxidant genes,crocin(0.5 The mRNA expression levels of mM)MAD,CAT and GPX were the highest.Among the related apoptotic genes,the expression of crocin(0.5 mM)Caspase-3 and TNF-a mRNA was the lowest(P<0.05),and the expression of Caspase-8 was compared with the control group.The difference was not significant but significantly lower than the other treatment groups.In summary,the addition of crocin can improve the antioxidant activity of sperm and reduce apoptosis,and has no obvious damage to sperm quality,and also contribute to sperm capacitation. |
