CtBP1/2 restrict DUX-dependent and independent 2C-like programs in mouse embryonic stem cells
TL;DR
It is shown that disruption of C-terminal binding protein 1/2 activates both DUX-dependent minor ZGA-associated genes and DUX-independent major ZGA- and post-ZGA-associated programs.
Abstract
After fertilization, maternally deposited mRNAs are cleared, and de novo transcription is initiated through zygotic genome activation (ZGA), a core event of the maternal-to-zygotic transition in mice. 2-cell-like cells (2CLCs), a rare MERVL-positive subpopulation of mouse embryonic stem cells, partially recapitulate transcriptional features of 2-cell embryos. Although canonical MERVL-high 2CLCs depend on DUX, Dux knockout embryos can develop to term, suggesting that 2CLC models do not fully capture DUX-independent pathways associated with preimplantation transcriptional programs. Here, we show that disruption of C-terminal binding protein 1/2 (Ctbp1/2) activates both DUX-dependent minor ZGA-associated genes and DUX-independent major ZGA- and post-ZGA-associated programs. Pramel7 is derepressed independently of DUX and contributes to subsets of both programs. PRAMEL7 overexpression partially rescues transcriptional defects caused by Dux deletion and is associated with UHRF1 downregulation and DNA demethylation-linked activation of post-ZGA-associated genes. These findings identify CtBP1/2 as repressors of multiple early embryonic transcriptional programs in mouse embryonic stem cells. CtBP1/2 loss activates both DUX-dependent minor-ZGA and DUX-independent major/post-ZGA transcriptional programs in mouse ESCs. PRAMEL7 links these pathways by promoting Dux expression and UHRF1 downregulation-associated DNA demethylation. Ctbp1/2 deletion expands MERVL-EGFP-positive ESCs and reveals distinct DUX-dependent high-GFP and DUX-independent low-GFP populations. CtBP1/2 directly represses rapid-response major-ZGA genes, including Pramel7 and Gata1. DUX controls delayed minor-ZGA genes. Ctbp1/2 depletion upregulates PRAMEL7, which activates post-ZGA-associated genes through UHRF1 downregulation. Ctbp1/2 deletion expands MERVL-EGFP-positive ESCs and reveals distinct DUX-dependent high-GFP and DUX-independent low-GFP populations. CtBP1/2 directly represses rapid-response major-ZGA genes, including Pramel7 and Gata1. DUX controls delayed minor-ZGA genes. Ctbp1/2 depletion upregulates PRAMEL7, which activates post-ZGA-associated genes through UHRF1 downregulation. CtBP1/2 loss activates both DUX-dependent minor-ZGA and DUX-independent major/post-ZGA transcriptional programs in mouse ESCs. PRAMEL7 links these pathways by promoting Dux expression and UHRF1 downregulation-associated DNA demethylation.