Effects Of ZSCAN4 And TEAD4 On The Acquisition Of Bovine Pluripotent Stem Cells

Induced pluripotent stem cells(i PSCs)have great potential for research and application in the fields of stem cell research,epigenetics and biomedicine.At present,great progress and achievements has been made in the study of i PS cells in humans and mice,but the research of embryonic stem cells(ESCs)and induced pluripotent stem cells has not made progress.In other large animals such as cattle.It was found that ZSCAN4 is an important factor which affects the development of preimplantation embryos.Specifically,ZSCAN4 participates in maintaining the long-term stability of telomeres and genomes in ES cells,and can prolong the length of telomeres in ES cells.In this study,lentiviral expression vectors of bovine Oct4,Sox2,Klf-4,c-Myc,Nanog and ZSCAN4 were constructed.Bovine i PS cells were infected by the combination of ZSCAN4 and other reprogramming factors,and compared with the other groups without ZSCAN4.The results showed that bovine i PS cells could be obtained in the groups expressing ZSCAN4 after 21 days of induction,while the other groups without expression of ZSCAN4 took 25 days.The number of i PS cells in the groups expressing ZSCAN4 was significantly higher than that in other groups without ZSCAN4 expression.Pluripotency analysis showed that bovine i PS cells can express OCT4 and NANOG pluripotent proteins in all groups.In addition,this study also discusses the effect of another embryonic development-related gene TEAD4 on the acquisition of bovine pluripotent stem cells.In this study,PLL3.7-TEAD4 knockdown vector was used to knock down TEAD4 in bovine fibroblasts to explore the function of TEAD4 in the induction of bovine i PS cells.The results showed that there was no significant difference in induction days and number of bovine i PS cells obtained between the groups with knockout TEAD4 and the groups without knockout TEAD4 in the case of the same reprogramming factor.But the number of alkaline phosphatase positive clones decreased in the groups with induced by OCT4,SOX2,KLF-4 and C-MYC in the case of knockout TEAD4.To sum up,ZSCAN4 can reduce the DNA damage after reprogramming of cells by stabilizing telomeres and genomes so that improving the induction efficiency of bovine i PS cells.The knockout of TEAD4 has no significant effect on the induction of bovine i PS cells.The decrease in the number of i PS cells in individual groups is probably caused by blocking the normal function of TEAD4 in somatic cells.This result may provide technical and theoretical support for the establishment of a more stable and more efficient induction method of bovine i PS cells in the future.