Project description:TET1, TET2 and TET3 are DNA demethylases with critical roles during early embryonic development and cell differentiation. To assess the contributions of TET proteins to cell function during early development, single and compound knockouts of Tet genes in mouse pluripotent embryonic stem cells (ESCs) were generated. ESCs lacking all alleles of Tet1 and Tet2, or all alleles of Tet1, Tet2 and Tet3 form epiblast-like cells and epiblast stem cells in culture, indicating that TET proteins are not required to transit between naïve, formative and primed pluripotency. Moreover, in differentiation protocols, ESCs with double-knockouts of Tet1 and Tet2 or triple-knockouts of Tet1, Tet2 and Tet3 do not differentiate normally , fail to activate somatic gene expression and retain expression of pluripotency transcription factors. Therefore, TET1 and TET2, but not TET3 act redundantly to facilitate somatic differentiation. Importantly, ESCs with double knockouts of Tet1 and Tet2, or triple knockouts of Tet1, Tet2 and Tet3 cells do differentiate into primordial germ cell-like cells (PGCLCs). Furthermore, PGCLC differentiation of Tet1, Tet2 double knockouts, or Tet1, Tet2, Tet3 triple knockouts occurs with high efficiency in the presence or absence of PGC-promoting cytokines. Moreover, acquisition of a PGCLC transcriptional programme occurs more rapidly in the absence of TET proteins. These results establish TET proteins as key regulators enabling epiblast cells to choose between somatic and germline fates. The functions of Tet1 and Tet2, but not Tet3 are required to enable epiblast cells to undergo somatic differentiation and in the absence of TET protein function, epiblast cell differentiation defaults to the germline.
Project description:The TET proteins TET1, TET2 and TET3 constitute a new family of dioxygenases that utilize molecular oxygen and the cofactors Fe(II) and 2-oxoglutarate to convert 5-methylcytosine (5mC) to 5-hydroxy-methylcytosine (5hmC) and further oxidation products in DNA1-5. Here we show that Tet1 and Tet2 have distinct roles in regulating 5hmC deposition and gene expression in mouse embryonic stem cells (mESC). Tet1 depletion in mESC primarily diminishes 5hmC levels at transcription start sites (TSS), whereas Tet2 depletion is mostly associated with decreased 5hmC in gene bodies relative to TSS. 5hmC is enriched at exon start and end sites, especially in exons that are highly expressed, and is significantly decreased upon Tet2 knockdown at the boundaries of high-expressed exons that are selectively regulated by Tet2. In differentiating murine B cells, Tet2 deficiency is associated with selective exon exclusion in the gene encoding the transmembrane phosphatase CD45. Tet2 depletion is associated with increased 5hmC and decreased 5mC at promoters/ TSS regions, possibly because of the redundant activity of Tet1. Together, these data indicate a complex interplay between Tet1 and Tet2 in mESC, and show that loss-of-function of a single TET protein does not necessarily lead to loss of 5hmC and a corresponding gain of 5mC, as generally assumed. The relation between Tet2 loss-of-function and selective changes in exon expression could potentially explain the frequent occurrence of both TET2 loss-of-function mutations and mutations in proteins involved in pre-mRNA splicing in myeloid malignancies in humans. Gene and exon expression analysis in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by RNA-sequencing. Mapping of 5-hydroxymethylcytosine in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by anti-CMS-seq. Mapping of methylcytosine in mESC, and Tet2 kd mESC by MeDIP-seq.
Project description:The TET proteins TET1, TET2 and TET3 constitute a new family of dioxygenases that utilize molecular oxygen and the cofactors Fe(II) and 2-oxoglutarate to convert 5-methylcytosine (5mC) to 5-hydroxy-methylcytosine (5hmC) and further oxidation products in DNA1-5. Here we show that Tet1 and Tet2 have distinct roles in regulating 5hmC deposition and gene expression in mouse embryonic stem cells (mESC). Tet1 depletion in mESC primarily diminishes 5hmC levels at transcription start sites (TSS), whereas Tet2 depletion is mostly associated with decreased 5hmC in gene bodies relative to TSS. 5hmC is enriched at exon start and end sites, especially in exons that are highly expressed, and is significantly decreased upon Tet2 knockdown at the boundaries of high-expressed exons that are selectively regulated by Tet2. In differentiating murine B cells, Tet2 deficiency is associated with selective exon exclusion in the gene encoding the transmembrane phosphatase CD45. Tet2 depletion is associated with increased 5hmC and decreased 5mC at promoters/ TSS regions, possibly because of the redundant activity of Tet1. Together, these data indicate a complex interplay between Tet1 and Tet2 in mESC, and show that loss-of-function of a single TET protein does not necessarily lead to loss of 5hmC and a corresponding gain of 5mC, as generally assumed. The relation between Tet2 loss-of-function and selective changes in exon expression could potentially explain the frequent occurrence of both TET2 loss-of-function mutations and mutations in proteins involved in pre-mRNA splicing in myeloid malignancies in humans. Gene and exon expression analysis in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by RNA-sequencing. Mapping of 5-hydroxymethylcytosine in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by anti-CMS-seq. Mapping of methylcytosine in mESC, and Tet2 kd mESC by MeDIP-seq.
Project description:The TET proteins TET1, TET2 and TET3 constitute a new family of dioxygenases that utilize molecular oxygen and the cofactors Fe(II) and 2-oxoglutarate to convert 5-methylcytosine (5mC) to 5-hydroxy-methylcytosine (5hmC) and further oxidation products in DNA1-5. Here we show that Tet1 and Tet2 have distinct roles in regulating 5hmC deposition and gene expression in mouse embryonic stem cells (mESC). Tet1 depletion in mESC primarily diminishes 5hmC levels at transcription start sites (TSS), whereas Tet2 depletion is mostly associated with decreased 5hmC in gene bodies relative to TSS. 5hmC is enriched at exon start and end sites, especially in exons that are highly expressed, and is significantly decreased upon Tet2 knockdown at the boundaries of high-expressed exons that are selectively regulated by Tet2. In differentiating murine B cells, Tet2 deficiency is associated with selective exon exclusion in the gene encoding the transmembrane phosphatase CD45. Tet2 depletion is associated with increased 5hmC and decreased 5mC at promoters/ TSS regions, possibly because of the redundant activity of Tet1. Together, these data indicate a complex interplay between Tet1 and Tet2 in mESC, and show that loss-of-function of a single TET protein does not necessarily lead to loss of 5hmC and a corresponding gain of 5mC, as generally assumed. The relation between Tet2 loss-of-function and selective changes in exon expression could potentially explain the frequent occurrence of both TET2 loss-of-function mutations and mutations in proteins involved in pre-mRNA splicing in myeloid malignancies in humans. Gene and exon expression analysis in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by RNA-sequencing. Mapping of 5-hydroxymethylcytosine in mESC, Tet1 knockdown mESC, and Tet2 knockdown mESC by anti-CMS-seq. Mapping of methylcytosine in mESC, and Tet2 kd mESC by MeDIP-seq.
Project description:Nephron endowment is a key determinant of later life hypertension and kidney disease. Here we studied whether epigenetic changes, specifically the ten–eleven translocation (Tet) DNA demethylase family, Tet1, Tet2, and Tet3-mediated active DNA hydroxymethylation is necessary for gene expression regulation and kidney differentiation. We generated mice with deletion of Tet1, Tet2 or Tet3 in Six2 positive nephron progenitors (NP). We did not observe changes in development or kidney function in mice with nephron progenitor-specific deletion of Tet1, Tet2, Tet3 or Tet1/Tet2 or Tet1/Tet3. On the other hand, mice with combined Tet2 and Tet3 loss in Six2-positive NPCs failed to form nephrons leading to kidney failure and perinatal death. Tet2 and Tet3 loss in Six2-positive NPs resulted in defect in mesenchymal to epithelial transition and renal vesicle differentiation. Whole genome bisulfite sequencing, single cell RNA sequencing, and gene and protein expression assay identified a defect in expression in genes in the WNT-β-catenin signaling pathway in absence of Tet2 and Tet3 due to a failure in demethylation of these loci. Our results indicate the key role of Tet2 and Tet3-mediated active cytosine hydroxymethylation in NPs in kidney development and nephron endowment.
Project description:We inactivated RYBP, YAF2, TET1, TET2, and TET3 in bronchial cells, individually and in combination, and observed widespread DNA methylation by performing whole genome bisulfite sequencing.