Membrane Protein Fam70a Regulates Meiotic Progression Of Mouse Oocytes

Mammalian oocytes produce haploid gametes by meiotic.A mass of maternal factors accumulated during oocyte maturation,which are extremely important to the early events of embryonic development.Those maternal factors are the guarantee of fertilization and embryonic development.They also play a very important role in the process of “maternal-zygotic-transition”.Therefore,the study on the meiotic maturation process of oocytes becomes particularly important.Fam70a,also known as Tmem225 A,is a member of the family of transmembrane proteins.However,as a transmembrane protein across the entire biofilm,its function of the oocytes meiosis is not yet clear.We firstly found that Fam70 a is an oocyteprominent protein concentrating at membrane of mouse oocytes.After knocking down Fam70 a by specific siRNA transfection of oocytes,we found that the absence of Fam70 a resulted in the arrest of oocyte development in the pre-MII phase.After 16 h culture in vitro,compared with the control group,Fam70a-knockdown group increased the degree of non-congressed chromosomes in the oocytes of the MII stage,resulting in the disorder of chromosome separation,the decrease of the split volume,and the increase in polar body volume tends to symmetrical split.After knocking down Fam70 a in oocytes,the fertilization rate and the rate of 2-pronucleus decrease.These results suggest that Fam70 a may play a meaningful way in meiosis of oocytes.In addition,in terms of functional mechanisms,through IP-Masspec mass spectrometry,we have found a protein that may interact with Fam70a: β-catenin.After the specific knockdown of Fam70 a,the expression of inactive phosphorylated β-catenin was increased.Through analysis of literature and experiments,we speculated that Fam70 a may participate in the Wnt/β-catenin signaling pathway through the interaction of tumor factor APC and β-catenin,thus affecting the meiosis of mouse oocytes.