GSE113164
Transcriptional defects and reprogramming barriers in somatic cell nuclear reprogramming as revealed by single-embryo RNA sequencing
Nuclear reprogramming reinstates totipotency or pluripotency in somatic cells by changing their genetic transcription. This technology is widely used in medicine, animal husbandry and other industries. However, certain deficiencies, such as the poor developmental ability of reprogrammed nuclear transfer (NT) embryos and the low birth rate (less than 5%) of cloned animals, severely restrict the promotion of this technology. Multiple nuclear reprogramming barriers likely exist in the process of somatic nuclear reprogramming. Furthermore, the NT embryos obtained via this technology have transcriptional defects in embryonic development. To address these problems, in this study, two types of NT embryos were constructed using the same genetic background in mice. We detected the full transcriptome of all stages of NT embryos using single-cell RNA-seq and obtained the following results: 1) NT embryos have translation initiation defects during the minor zygotic genome activation (ZGA) period; NT embryos display RNA processing and RNA modification defects during the major ZGA period, and their protein kinase activity in protein phosphorylation exhibits defects during blastocyst formation; and 2) 2003 constant genes cannot be reprogrammed in cumulus cells (CCs) and mouse embryo fibroblast cells (MEFs); of these constant genes, 399/583 reprogramming barrier genes (RBGs) continue to mis-transcribe from the pronuclear stage to the blastula stage, and the same 136 RBGs are found in both the CCs and MEFs. The main functions of these RBGs is to positively regulate certain factors. In conclusion, our study offers full transcriptome blueprints of all stages of CC donor NT embryos, MEF donor NT embryos and in vivo embryos and reveals new transcriptional defects and reprogramming barriers in nuclear reprogramming. These findings provide insight for further mechanism studies investigating somatic nuclear reprogramming. Overall design: The transcriptomic analyses of in vivo fertilized embryos, cumulus cell NT embryos and MEF NT embryos were systematically performed. First, the dynamic changes in gene transcription during the entire embryonic developmental process from the pronuclear stage to the blastocyst stage were systematically examined in these three types of embryos separately. Then, the differences in the gene transcripts among these embryos and donor cells were intensively explored.