Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:Zygotic genome activation (ZGA) is a critical post-fertilization step that promotes totipotency and allows different cell fates to emerge in the developing embryo. MERVL, murine endogenous retrovirus-L, is transiently upregulated at the 2-cell stage around the time of ZGA. Although MERVL expression is widely used as a marker of totipotency, the role of this retrotransposon in mouse embryogenesis remains elusive. Here, we develop methods for consistent knockdown (KD) and inactivation of interspersed copies of MERVL and show that MERVL transcripts, but not encoded retroviral proteins and their long terminal repeat (LTR) promoter that drives chimeric transcripts with host genes, is essential for accurate regulation of the host transcriptome and chromatin state during preimplantation development. Both KD and CRISPRi-based repression of MERVL result in embryonic lethality due to defects in differentiation and genomic stability. Furthermore, transcriptome and epigenome analysis revealed that loss of MERVL transcript led to retain an accessible chromatin state at, and aberrant expression of, a subset of 2-cell specific genes at mid-preimplantation stages. Taken together, our results suggest a model in which an endogenous retrovirus plays a critical role in regulating host cell fate potential.
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:To better understand transcriptional regulation during human oogenesis and pre-implantation embryonic development, we defined stage-specific transcription, which revealed cleavage stage as highly distinctive. We present multiple lines of evidence that two cleavage-specific homologs, mouse mDUX and human DUX4, each activate hundreds of cleavage-specific endogenous genes (e.g. ZSCAN4, ZFP352, KDM4E) and retroviral elements (MERVL/HERVL-family). Remarkably, mDux expression converts mouse ESCs into two-cell embryo-like (2C-like) cells by binding to MERVL promoters/enhancers and restoring the chromatin landscape (via ATACseq) to the pattern of mouse two-cell embryos
Project description:Endogenous retrovirus MERVL is specifically expressed in a minority of embryonic stem cells. To determine the restrain mechanism of MERVL, we knocked out Ssrp1 and analyzed the effect on the expression of transposable elements and coding genes.
Project description:Endogenous retrovirus MERVL is specifically expressed in a minority of embryonic stem cells and 2-cell embryos. To determine the function of MERVL transcripts, we knocked down MuERVL and analyzed the effect on the expression of MERVL and its targeting genes. It turns out the downregulation of MuERVL would lead to downregulation of MERVL nearby genes. This study extends our understandings of the machanism by which MERVL regulates its neatby genes.
