Supplement Of Betaine Into Embryo Culture Medium Can Rescue Injury Effect Of Ethanol On Mouse Embryo Development

Mammal embryos can be impaired by mother's excessive ethanol uptake,which induces a higher level of reactive oxygen species(ROS)and interferes in one carbon unit metabolism.Betaine exists in various stages of early embryonic development and has a stable level,has osmotic protection and antioxidant function,and can be used as a source of methyl donors to participate in one-carbon metabolism.In this article,the direct effect of adding ethanol and betaine to the culture medium on mouse embryo development was analyzed through in vitro culture,uterine transplantation and immunofluorescence staining system.It was verified that betaine can effectively repair the embryonic development after ethanol damage and preliminary explored the repair mechanism of betaine.1.Dose effect relationship between ethanol concentration and embryonic developmentBy adding different concentrations of ethanol in the culture medium,the direct effect of ethanol on mouse embryo development was observed and the development rate of the blastocyst was counted,thus revealing the dose-effect relationship between ethanol and embryonic development.At the same time,we have found that in vitro culture of early embryos using a medium containing 1% ethanol will have a significant effect on early embryonic development.The detrimental effects of ethanol on early embryos will persist throughout the developmental period,including the rate of formation and implantation of the lower blastocysts and deterioration of fetal development after implantation.2.Supplementation of betaine in embryonic medium can repair the damage of ethanol on mouse embryonic development.By adding 50 ?g/mL betaine to the culture medium,the damage of ethanol to early embryos can be effectively recovered and relieved,including recovery of ethanol caused by blastocyst formation rate and blastocyst implantation rate.At the same time,the betaine-containing betaine supplemented with betaine was transplanted into mice,and thedegree of fetal development at 8 days after implantation was observed.It can be found that the degree of inhibition and damage of fetal development by ethanol can be significantly improved.3.Preliminary study on the mechanism of betaine repair ethanol on the development of mouse embryos.By ROS fluorescent staining of ROS levels in embryos at different times,it was found that the addition of betaine can reduce the level of ROS in embryonic cells caused by ethanol and repair embryonic development at each stage of ethanol damage.Betaine is known as trimethyl glycine.To rule out the ability of betaine to act as a methyl donor,it was investigated whether betaine repairs damage to embryonic development through osmotic protection.We added glycine,which also had osmotic protection,to the culture medium.We found that the addition of glycine to the culture medium did not repair embryo development damage as did betaine.In addition,the results of 5-methylcytosine immunoassay showed that addition of betaine to the culture medium can reduce the increase of genomic DNA methylation of blastocyst cells induced by 1% ethanol,while glycine can not play the same role.The above series of experiments show that betaine can effectively repair the development of embryos damaged by ethanol,and may repair this damage by reducing the level of ROS caused by ethanol and restoring the level of genomic DNA methylation in blastocysts.