Effects Of Different Developmental Environments On The Expression Of Genes Related To The Developmental Ability Of Mouse Oocytes With Different Chromatin Configurations

Assisted reproductive technology has now become an important method to solve infertility and has good application prospects.In this method,the oocytes need to undergo in vitro maturation(IVM),fertilization and embryos.Therefore,obtaining oocytes with higher developmental capacity is the key to successfully obtaining in vitro embryos(IVP).In addition,zearalenone(ZEN)and stress are common causes of decreased reproductive function of female animals,which seriously threaten the reproductive health of humans and animals.By observing the chromatin configuration changes of mice with different ages,ZEN treatment,and restraint stress,using RTq PCR method to determine the development ability of surrounded nucleolus(SN)and nonsurrounded nucleolus(NSN)oocytes The expression of its related genes,elucidating the relationship between oocyte chromatin configuration and developmental ability and gene transcription,and the influence of different environments on the developmental ability of oocytes are of great significance to the reproductive health of humans and animals.The results of the study are as follows:(1)Compared with adult mouse oocytes with different chromatin configurations,the proportion of young mouse NSN oocytes that can develop to 2-cell embryos is 38.1%,and the proportion of young mouse SN oocytes that can develop to The proportion of 4-cell embryos is38.9%;the proportion of adult mouse SN oocytes that can develop into 2-cell embryos is 92%,and the proportion of 4-cell embryos that can develop into 8-cell embryos is 82.6%.Although they are all SN type oocytes,the developmental ability of oocytes may be significantly affected due to the difference of follicular microenvironment;(2)Compared with the control group,the ratio of oocytes to 4-cell embryos and morulas through parthenogenetic activation in the ZEN injection group decreased by nearly 20%,indicating that ZEN significantly reduced the development ability of oocytes;(3)Compared with the control group,the continuous restraint stress group showed a significant decrease in the ratio of GV phase,SN configuration and pSN of mouse oocytes,while the ratio of cNSN configuration,cpNSN configuration and cpSN configuration oocytes Both are significantly improved,and the rate of 4-cell embryos produced after restraint stress in subsequent development experiments is only 47.4%,indicating that restraint stress will cause chromatin to agglutinate in advance,thereby significantly reducing the development ability of oocytes;(4)Expression of genes OCT4,Stella,Mater,Zar1 and Mapk8 that are beneficial to the development of oocytes in the group with a high proportion of SN-type oocytes after different treatments during the in vitro maturation of oocytes The expression level of unfavorable genes Foxj2,SHP1 and Bax was significantly reduced,and the mRNA expression level of Bcl-2 was significantly higher than that of Bax.Therefore,due to the different follicular microenvironment and the effects of environmental pollutants(ZEN)and stress,the ratio of the chromatin configuration of mouse oocytes will be affected,and then the expression of different genes will be affected,thereby affecting the development ability of oocytes in vitro.