Embryonic transcription is controlled by maternally defined chromatin state
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ABSTRACT:
ORGANISM(S): Xenopus tropicalis
PROVIDER: GSE67974 | GEO | 2015/12/15
SECONDARY ACCESSION(S): PRJNA281501
REPOSITORIES: GEO
Similar Datasets
Project description:During development histone modifying enzymes are required for cell identity and lineage commitment, however little is known about the regulatory origins of the epigenome during embryonic development. Here we generate a comprehensive set of embryonic epigenome reference maps, which we use to determine the extent to which maternal factors shape chromatin state in Xenopus embryos. Using α-amanitin to inhibit zygotic transcription, we find that the majority of H3K4me3 and H3K27me3-enriched regions form a maternally defined epigenetic regulatory space with an underlying logic of hypomethylated islands. This maternal regulatory space extends to a substantial proportion of neurula stage-activated promoters. In contrast, p300-recruitment to distal regulatory regions requires embryonic transcription at most loci. The results show that H3K4me3 and H3K27me3 are part of a regulatory space that exerts an extended maternal control well into post-gastrulation development, and highlight the combinatorial action of maternal and zygotic factors through proximal and distal regulatory sequences. We have performed ChIP-sequencing of eight histone modifications, RNA polymerase II (RNAPII) and the enhancer protein p300 at five stages of development: blastula (st. 9), gastrula (st. 10.5, 12.5), neurula (st. 16) and tailbud (st. 30). These experiments allow identification of enhancers (H3K4me1, p300), promoters (H3K4me3, H3K9ac), transcribed regions (H3K36me3, RNAPII) and repressed and heterochromatic domains (H3K27me3, H3K9me2, H3K9me3, H4K20me3). In addition we generated pre-MBT (st. 8) maps for three histone modifications (H3K4me3, H3K9ac, H3K27me3) and single-base resolution DNA methylome maps using whole genome bisulfite sequencing of blastula and gastrula (st. 9 and 10.5) embryos. To determine the maternal and zygotic contributions to chromatin state, we used alpha-amanitin to block embryonic transcription. Fertilised eggs were injected with 2.3 nl of 2.67 ng/ul alpha-amanitin and developed until the control embryos reached mid-gastrulation. Alpha-amanitin and control embryos were used for RNA-seq and ChIP-seq of RNAPII, H3K4me3, H3K27me3 and p300. For all ChIP-seq samples of the epigenome reference maps and RNAPII ChIP-seq samples of the α-amanitin experiments three biological replicates of different chromatin isolations of 45 embryos were pooled. Two biological replicates for H3K4me3 (α-amanitin injected: resp. 90 and 56 embryo equivalents (eeq); control: resp. 45 and 67 eeq), H3K27me3 (α-amanitin injected: resp. 90 and 180 eeq; control: resp. 45 and 202 eeq) and p300 (α-amanitin injected: resp. 112 and 56 eeq; control: resp. 112 and 67 eeq) ChIP-seq samples of the α-amanitin experiments were generated. For RNA-seq samples of the α-amanitin experiments RNA from 5 embryos from one biological replicate was isolated and depleted of ribosomal RNA
2015-12-15 | E-GEOD-67974 | biostudies-arrayexpress
Project description:[PROJECT] After fertilization the embryonic genome is inactive until transcription is initiated during the maternal-zygotic transition (MZT). This universal process coincides with the formation of pluripotent cells, which in mammals can be used to generate embryonic stem (ES) cells. To study the changes in chromatin structure that accompany zygotic genome activation and pluripotency, we mapped the genomic locations of histone H3 modifications before and after MZT in zebrafish embryos. Repressive H3 lysine 27 trimethylation (H3K27me3) and activating H3 lysine 4 trimethylation (H3K4me3) are only detected after MZT. H3K4me3 marks more than 80% of genes, including many developmental regulatory genes that are also occupied by H3K27me3. Sequential chromatin immunoprecipitation demonstrates that both methylation marks occupy the same promoter regions, revealing that the bivalent chromatin domains found in cultured ES cells also exist in embryos. In addition, we find a large group of genes that are monovalently marked by H3K4me3 but not H3K27me3. These H3K4me3 monovalent genes are neither expressed nor stably bound by RNA polymerase II. Closer inspection of in vitro data sets reveals similar monovalent H3K4me3 domains in ES cells. The analysis of an inducible transgene indicates that H3K4me3 domains can form in the absence of sequence-specific transcriptional activators or stable association with RNA pol II. These results suggest that bivalent and monovalent domains might poise embryonic genes for activation and that the chromatin profile associated with pluripotency is established during MZT. [SAMPLES] ChIPchip analysis of histone modifications (H3K4me3, H3K27me3, H3K36me3) and RNA polymerase II in pre MZT (256-cell) and post MZT (4hpf; dome/30% epiboly) wt zebrafish embryos. H3K4me3, H3K27me3, H3K36me3 and PolII ChIP-chip at 256 cell stage (one replicate) and 4hpf (dome/30% epiboly) (two replicates)
2010-01-25 | E-GEOD-20023 | biostudies-arrayexpress
Project description:Polycomb group (PcG) proteins are transcriptional repressors important to maintain cell identity during embryonic development. Ezh2, the catalytic subunit of the Polycomb Repressive Complex 2, is responsible for placing the epigenetic repressive mark histone H3 lysine 27 trimethylation (H3K27me3). In contrast to results in mouse models, zebrafish embryos mutant for both maternal and zygotic ezh2 (MZezh2) can form a normal body plan at 1 day post fertilization (dpf) but die at 2 dpf, exhibiting pleiotropic phenotypes. To elucidate the specificity of PcG-mediated repression during early zebrafish development, we conducted in depth analysis of the transcriptome, epigenome, and proteome of the MZezh2 mutant embryos at 1 dpf. We found that, despite modifications in the epigenetic landscape, transcriptome and proteome analysis revealed only minor changes in gene and protein expression levels.
2019-09-09 | PXD010922 | Pride
Project description:Wnt signal usually functions as a spatial gradient. A localized Wnt3a can induce asymmetric division of mouse embryonic stem cells, whereas proximal daughter cells maintain self-renew and distal daughter cells acquire hallmarks of differentiation. Here, we develop an approach, SET-seq (same cell epigenome and transcriptome sequencing), to jointly profile epigenome and transcriptome in the same single cell. By utilizing SET-seq, we profile H3K27me3 and H3K4me3 with gene expression in Wnt3a induced asymmetric cell division. H3K27me3, but not H3K4me3, is correlatedly changed with gene expression. Single cells clustered by H3K27me3 recapitulate the clusters defined by gene expression. Furthermore, Aebp2, which is the regulator of H3K27me3, is important for the cell-fate decision with localized Wnt signal. Our results provide a convenient way to jointly profile epigenome and transcriptome in the same cell, and uncover the mechanistic insights into the gene regulatory programs for maintaining and resetting stem cell fate during differentiation.
2021-09-05 | GSE168637 | GEO
Project description:[PROJECT] After fertilization the embryonic genome is inactive until transcription is initiated during the maternal-zygotic transition (MZT). This universal process coincides with the formation of pluripotent cells, which in mammals can be used to generate embryonic stem (ES) cells. To study the changes in chromatin structure that accompany zygotic genome activation and pluripotency, we mapped the genomic locations of histone H3 modifications before and after MZT in zebrafish embryos. Repressive H3 lysine 27 trimethylation (H3K27me3) and activating H3 lysine 4 trimethylation (H3K4me3) are only detected after MZT. H3K4me3 marks more than 80% of genes, including many developmental regulatory genes that are also occupied by H3K27me3. Sequential chromatin immunoprecipitation demonstrates that both methylation marks occupy the same promoter regions, revealing that the bivalent chromatin domains found in cultured ES cells also exist in embryos. In addition, we find a large group of genes that are monovalently marked by H3K4me3 but not H3K27me3. These H3K4me3 monovalent genes are neither expressed nor stably bound by RNA polymerase II. Closer inspection of in vitro data sets reveals similar monovalent H3K4me3 domains in ES cells. The analysis of an inducible transgene indicates that H3K4me3 domains can form in the absence of sequence-specific transcriptional activators or stable association with RNA pol II. These results suggest that bivalent and monovalent domains might poise embryonic genes for activation and that the chromatin profile associated with pluripotency is established during MZT. [SAMPLES] ChIPchip analysis of histone modifications (H3K4me3, H3K27me3, H3K36me3) and RNA polymerase II in pre MZT (256-cell) and post MZT (4hpf; dome/30% epiboly) wt zebrafish embryos.
2010-01-26 | GSE20023 | GEO
Project description:The oocyte epigenome plays critical roles in mammalian gametogenesis and embryogenesis. Yet, how it is established remains elusive. Here, we report that histone-lysine N-methyltransferase SETD2, an H3K36me3 methyltransferase, is a crucial regulator of the mouse oocyte epigenome. Deficiency in Setd2 leads to extensive alterations of the oocyte epigenome, including the loss of H3K36me3, failure in establishing the correct DNA methylome, invasion of H3K4me3 and H3K27me3 into former H3K36me3 territories and aberrant acquisition of H3K4me3 at imprinting control regions instead of DNA methylation. Importantly, maternal depletion of SETD2 results in oocyte maturation defects and subsequent one-cell arrest after fertilization. The preimplantation arrest is mainly due to a maternal cytosolic defect, since it can be largely rescued by normal oocyte cytosol. However, chromatin defects, including aberrant imprinting, persist in these embryos, leading to embryonic lethality after implantation. Thus, these data identify SETD2 as a crucial player in establishing the maternal epigenome that in turn controls embryonic development.
2019-05-01 | GSE112832 | GEO
Project description:The oocyte epigenome plays critical roles in mammalian gametogenesis and embryogenesis. Yet, how it is established remains elusive. Here, we report that histone-lysine N-methyltransferase SETD2, an H3K36me3 methyltransferase, is a crucial regulator of the mouse oocyte epigenome. Deficiency in Setd2 leads to extensive alterations of the oocyte epigenome, including the loss of H3K36me3, failure in establishing the correct DNA methylome, invasion of H3K4me3 and H3K27me3 into former H3K36me3 territories and aberrant acquisition of H3K4me3 at imprinting control regions instead of DNA methylation. Importantly, maternal depletion of SETD2 results in oocyte maturation defects and subsequent one-cell arrest after fertilization. The preimplantation arrest is mainly due to a maternal cytosolic defect, since it can be largely rescued by normal oocyte cytosol. However, chromatin defects, including aberrant imprinting, persist in these embryos, leading to embryonic lethality after implantation. Thus, these data identify SETD2 as a crucial player in establishing the maternal epigenome that in turn controls embryonic development.
2019-05-01 | GSE112834 | GEO
Project description:The oocyte epigenome plays critical roles in mammalian gametogenesis and embryogenesis. Yet, how it is established remains elusive. Here, we report that histone-lysine N-methyltransferase SETD2, an H3K36me3 methyltransferase, is a crucial regulator of the mouse oocyte epigenome. Deficiency in Setd2 leads to extensive alterations of the oocyte epigenome, including the loss of H3K36me3, failure in establishing the correct DNA methylome, invasion of H3K4me3 and H3K27me3 into former H3K36me3 territories and aberrant acquisition of H3K4me3 at imprinting control regions instead of DNA methylation. Importantly, maternal depletion of SETD2 results in oocyte maturation defects and subsequent one-cell arrest after fertilization. The preimplantation arrest is mainly due to a maternal cytosolic defect, since it can be largely rescued by normal oocyte cytosol. However, chromatin defects, including aberrant imprinting, persist in these embryos, leading to embryonic lethality after implantation. Thus, these data identify SETD2 as a crucial player in establishing the maternal epigenome that in turn controls embryonic development.
2019-05-01 | GSE112833 | GEO
Project description:Maternal-to-zygotic transition (MZT) is a conserved and fundamental process during which the maternal environment of oocyte transits to the zygotic genome driven expression program, and terminally differentiated oocyte and sperm are reprogrammed to totipotency. It is initiated by maternal mRNAs and proteins during the period of zygotic genome quiescence after fertilization, followed by a gradual switch to zygotic genome activation and accompanied by clearance of maternal RNAs and proteins. A key question for embryonic development is how MZT process is regulated. Here we used a low-input proteomic analysis to measure the proteomic dynamics during early development of mouse maternal-to-zygotic transition.
2023-03-27 | PXD041023 | Pride
Project description:The epigenome plays critical roles in controlling gene expression and development. However, how the parental epigenomes transit to the zygotic epigenome in early development remains elusive. Here, we show parental-to-zygotic transition in zebrafish involves extensive erasure of parental epigenetic memory starting by methylating gametic enhancers. Surprisingly, this occurs even prior to fertilization for sperm. Both parental enhancers lose histone marks by the 4-cell stage, and zygotic enhancers are not activated until around zygotic genome activation (ZGA). By contrast, many promoters remain hypomethylated and, unexpectedly, acquire de novo histone acetylation as early as at the 4-cell stage. They then resolve into either activated or repressed promoters upon ZGA. Maternal depletion of histone acetyltransferases results in aberrant ZGA and early embryonic lethality. Finally, such reprogramming is largely driven by maternal factors with zygotic products contributing to embryonic enhancer activation. Thus, these data revealed widespread enhancer dememorization and promoter priming during parental-to-zygotic transition.
2018-10-25 | GSE114954 | GEO