Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Chromatin dynamics and genome-wide profiling of repetitive elements during early mammalian embryogenesis.

ABSTRACT: We have used repetitive elements, including retrotransposons, as model loci to address how and when heterochromatin forms during development. High throughput RNA-sequencing using a Nano-CAGE protocol throughout early embryogenesis revealed that the expression of repetitive elements is abundant in embryonic cells, highly dynamic and stage-specific, with most repetitive elements becoming repressed before implantation. Furthermore, we show that Line L1 elements and IAP retrotransposons become reactivated from both parental genomes in mouse embryos after fertilisation, indicating an open chromatin configuration at the beginning of development. Our data show that the reprogramming process that follows fertilisation is accompanied by a robust transcriptional activation of retrotransposons and suggests that expression of repetitive elements is initially regulated through an RNA-dependent mechanism in mammals. Genome Wide profiling of CAGE transcripts using Nano-CAGE and RNAseq in oocytes and 3 different stages of mouse pre-implantation development

ORGANISM(S): Mus musculus

SUBMITTER: Stephanie Le Gras

PROVIDER: E-GEOD-39849 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:In mammals, DNA methylation is essential for protecting repetitive sequences from aberrant transcription, translocation, and homologous recombination. However, DNA hypomethylation occurs during specific developmental stages (e.g. preimplantation embryos) and in certain cell types (e.g., primordial germ cells). The absence of dysregulated repetitive elements in these cells suggests the existence of alternative mechanisms that prevent genome instability triggered by DNA hypomethylation. In this report, we seek to elucidate the factors that play a critical role in ensuring genome stability by focusing on DAXX and ATRX, two proteins that have been linked to transcriptional control and epigenetic regulation. We carried out ChIP-seq and RNA-seq analyses to compare the genome-wide binding and transcriptome profiles of DAXX and ATRX in mouse ES (mES) cells triple knocked out for the three mammalian DNA methyltransferases (DNMTs) (TKO cells) to those in wildtype mES cells. Our data indicate that DAXX and ATRX are distinct in their chromatin-binding profiles and highly co-enriched at tandem repetitive elements. Global DNA hypomethylation, as was the case in TKO cells, further promoted the recruitment of the DAXX/ATRX complex to tandem repeat sequences including IAP (intracisternal A‐particle) retrotransposons and telomeres. Inhibition of DAXX or ATRX in cells with hypomethylated genomes (e.g., TKO cells, mES cells cultured in ground-state conditions, and preimplantation embryos) increased aberrant transcriptional de-repression of repeat elements and dysfunction at telomeres. Furthermore, we provide evidence that DAXX/ATRX-dependent silencing may occur through DAXX’s interaction with SUV39H1 and increased H3K9me3 on repetitive sequences. Our study suggests that DAXX and ATRX are important for safeguarding the genome, particularly in silencing repetitive elements in the absence of DNA methylation. We tested the hypothesis that the DAXX/ATRX complex participates in protecting repetitive elements in the absence of DNA methylation. To this end, we investigated genome-wide chromatin targeting of DAXX and ATRX in wildtype mES cells, and in mES cells that exhibit extensive loss of DNA methylation due to homozygous knockout of all three DNA.

Dataset Information

Chromatin dynamics and genome-wide profiling of repetitive elements during early mammalian embryogenesis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure