Preventing CpG hypermethylation in oocytes safeguards mouse development [WGBS 4-cell]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE304582 | GEO | 2025/09/03
REPOSITORIES: GEO
Similar Datasets
Project description:Except for regulatory CpG-island sequences, genomes of most mammalian cells are widely DNA-methylated. In oocytes though, DNAme is largely confined to transcribed regions. The mechanisms restricting de novo DNAme in oocytes and the relevance thereof for zygotic genome activation and embryonic development are largely unknown. Here we show that KDM2A and KDM2B, two histone demethylases, prevent genome-wide accumulation of histone H3 lysine 36 di-methylation, thereby impeding DNMT3A-catalyzed DNAme. We demonstrate that aberrant DNAme at CpG-islands inherited from Kdm2a/Kdm2b double mutant oocytes represses gene transcription in two-cell embryos. Aberrant maternal DNAme impairs pre-implantation embryonic development which is suppressed by Dnmt3a deficiency during oogenesis. Hence, KDM2A/KDM2B are essential for confining the oocyte methylome, thereby conferring competence for early embryonic development. Our research implies that the reprogramming capacity eminent to early embryos is insufficient for erasing aberrant DNAme from maternal chromatin, and that early development is vulnerable to gene dosage haplo-insufficiency effects.
2025-03-27 | GSE234968 | GEO
Project description:DNA methylation (DNAme) controls gene expression, genome stability and cell identity in many mammalian organisms. Genomes of most somatic cells and spermatozoa are largely methylated, apart from CpG-dense sequences including gene promoters1. In mouse oocytes, DNAme is mostly limited to transcribed regions2,3. The mechanisms restricting global DNAme acquisition in developing oocytes and the relevance thereof for regulating gene expression and embryo development after fertilization are unknown. Here we show that the histone H3 lysine 36 dimethyl (H3K36me2) demethylases KDM2A and KDM2B redundantly execute multiple chromatin functions during oocyte development, which are vital to pre- and post-implantation development. Firstly, by serving as recruitment factors of variant Polycomb Repressive Complex 1 (vPRC1), they control genome-wide H2A mono-ubiquitination deposition (H2AK119u1) and PRC1-dependent gene repression4. Secondly, as demethylases, KDM2A/KDM2B prevent global H3K36me2 accumulation, thereby impeding DNMT3A-catalyzed de novo DNAme within PRC1-controlled promoter, genic, and intergenic regions, and even at non-PRC1-controlled CpG-dense gene promoters5. Decisively, we demonstrate that aberrant Dnmt3a-dependent DNAme established in Kdm2a/Kdm2b double mutant oocytes represses transcription from maternal loci in two-cell embryos and impairs pre-implantation development. Hence, KDM2A/KDM2B are essential for defining the appropriate oocyte DNA methylome which in turn conveys competence for early embryonic development. Our research implies that the reprogramming capacity eminent to early embryos is insufficient to erase aberrant DNAme from maternal chromatin. Lastly, our work shows that early development is vulnerable to gene dosage haplo-insufficiency effects, possibly in a parental-specific manner.
2025-03-27 | GSE234967 | GEO
Project description:DNA methylation (DNAme) controls gene expression, genome stability and cell identity in many mammalian organisms. Genomes of most somatic cells and spermatozoa are largely methylated, apart from CpG-dense sequences including gene promoters1. In mouse oocytes, DNAme is mostly limited to transcribed regions2,3. The mechanisms restricting global DNAme acquisition in developing oocytes and the relevance thereof for regulating gene expression and embryo development after fertilization are unknown. Here we show that the histone H3 lysine 36 dimethyl (H3K36me2) demethylases KDM2A and KDM2B redundantly execute multiple chromatin functions during oocyte development, which are vital to pre- and post-implantation development. Firstly, by serving as recruitment factors of variant Polycomb Repressive Complex 1 (vPRC1), they control genome-wide H2A mono-ubiquitination deposition (H2AK119u1) and PRC1-dependent gene repression4. Secondly, as demethylases, KDM2A/KDM2B prevent global H3K36me2 accumulation, thereby impeding DNMT3A-catalyzed de novo DNAme within PRC1-controlled promoter, genic, and intergenic regions, and even at non-PRC1-controlled CpG-dense gene promoters5. Decisively, we demonstrate that aberrant Dnmt3a-dependent DNAme established in Kdm2a/Kdm2b double mutant oocytes represses transcription from maternal loci in two-cell embryos and impairs pre-implantation development. Hence, KDM2A/KDM2B are essential for defining the appropriate oocyte DNA methylome which in turn conveys competence for early embryonic development. Our research implies that the reprogramming capacity eminent to early embryos is insufficient to erase aberrant DNAme from maternal chromatin. Lastly, our work shows that early development is vulnerable to gene dosage haplo-insufficiency effects, possibly in a parental-specific manner.
2025-03-27 | GSE234965 | GEO
Project description:DNA methylation (DNAme) controls gene expression, genome stability and cell identity in many mammalian organisms. Genomes of most somatic cells and spermatozoa are largely methylated, apart from CpG-dense sequences including gene promoters1. In mouse oocytes, DNAme is mostly limited to transcribed regions2,3. The mechanisms restricting global DNAme acquisition in developing oocytes and the relevance thereof for regulating gene expression and embryo development after fertilization are unknown. Here we show that the histone H3 lysine 36 dimethyl (H3K36me2) demethylases KDM2A and KDM2B redundantly execute multiple chromatin functions during oocyte development, which are vital to pre- and post-implantation development. Firstly, by serving as recruitment factors of variant Polycomb Repressive Complex 1 (vPRC1), they control genome-wide H2A mono-ubiquitination deposition (H2AK119u1) and PRC1-dependent gene repression4. Secondly, as demethylases, KDM2A/KDM2B prevent global H3K36me2 accumulation, thereby impeding DNMT3A-catalyzed de novo DNAme within PRC1-controlled promoter, genic, and intergenic regions, and even at non-PRC1-controlled CpG-dense gene promoters5. Decisively, we demonstrate that aberrant Dnmt3a-dependent DNAme established in Kdm2a/Kdm2b double mutant oocytes represses transcription from maternal loci in two-cell embryos and impairs pre-implantation development. Hence, KDM2A/KDM2B are essential for defining the appropriate oocyte DNA methylome which in turn conveys competence for early embryonic development. Our research implies that the reprogramming capacity eminent to early embryos is insufficient to erase aberrant DNAme from maternal chromatin. Lastly, our work shows that early development is vulnerable to gene dosage haplo-insufficiency effects, possibly in a parental-specific manner.
2025-03-27 | GSE234966 | GEO
Project description:Oocytes must accumulate and store maternal factors such as proteins during growth to sustain the first stages of embryonic development. How mammalian oocytes store maternal proteins is not understood. Here, we show that mouse and human oocytes store proteins on cytoplasmic lattices. With super-resolution light microscopy and electron tomography, we demonstrate that cytoplasmic lattices are twisted filament bundles formed by proteins of the subcortical maternal complex, filling the entire ooplasm. The lattices were associated with many proteins that have crucial functions during early embryo development, including proteins controlling genome methylation. Loss of cytoplasmic lattices prevented the accumulation of these proteins and resulted in early embryonic arrest. Thus, cytoplasmic lattices are important for storage of essential maternal proteins and the developmental success of early mammalian embryos.
2023-10-23 | PXD038575 | Pride
Project description:H3K36 methylation plays an important role in gene regulation. The role of H3K36 demethylase Kdm2b has been well studied. However, the role of Kdm2a in embryonic stem cells are still unkonwn. To study the function of Kdm2a in embryonic stem cells. We used CRISPR-gRNA system to knockout Kdm2a. We analyzed the gene expression change and identified target genes and repeats of Kdm2a. We uncovered a novel role of Kdm2a in regulating gene expression in embryonic stem cells.
2019-08-20 | GSE117148 | GEO
Project description:CpG island elements are associated with most mammalian gene promoters, yet how they contribute to gene regulation remains poorly understood. Recently it has become clear that a subset of CpG islands in embryonic stem cells can act as polycomb response elements and are recognized by the polycomb silencing systems to regulate the expression of genes involved in pluripotency and early developmental transcription programs. How CpG islands function mechanistically as nucleation sites for polycomb repressive complexes remains unknown. Here we discover that the KDM2B protein, by virtue of its ZF-CxxC DNA binding domain, specifically recognizes non-methylated DNA in CpG islands elements genome-wide. Through a physical interaction with the polycomb repressive complex 1 (PRC1), KDM2B targets PRC1 to CpG islands where it contributes to H2AK119ub1 and gene repression at a subset of polycomb targets. Unexpectedly, we also find that CpG islands are occupied by low levels of PRC1 throughout the genome, suggesting that the KDM2B-PRC1 complex may sample CpG island associated genes for susceptibility to polycomb mediated silencing. These observations demonstrate an unexpected and direct link between recognition of CpG islands by KDM2B and targeting of the polycomb repressive system. This provides the basis for a new model describing the functionality of CpG islands as mammalian PREs. ChIP-Seq to compare KDM2A vs. KDM2B genome-wide binding profiles and to understand the contribution of KDM2B to RING1B nucleation. Binding of Kdm2a and Kdm2b to the genome was examined in wildtype mESC, and Kdm2b and Ring1b in mESC where Kdm2b has been stably knocked down by shRNA.
2012-12-26 | E-GEOD-40860 | biostudies-arrayexpress
Project description:De novo DNA methylation (DNAme) during mammalian spermatogenesis yields a densely methylated genome, with the exception of CpG islands (CGIs), which are hypomethylated in sperm. Following fertilization, the paternal genome undergoes widespread DNAme loss before the first S-phase. Paradoxically, recent mass spectrometry analysis revealed that a low level of de novo DNAme occurs exclusively on the zygotic paternal genome. However, the genomic loci involved and impact on genic transcription was not addressed. Here, we employ allele-specific analysis of whole-genome bisulphite sequencing (WGBS) data and show that a number of genomic loci, including several dozen CGI promoters, are de novo methylated on the paternal genome in 2-cell embryos. A subset of these promoters maintain DNAme through development to the blastocyst stage. Consistent with zygotic paternal DNAme acquisition (PDA), many of these loci are hypermethylated in androgenetic blastocysts but hypomethylated in parthenogenetic blastocysts. Strikingly, PDA is lost following maternal deletion of Dnmt3a. Furthermore, a subset of promoters showing PDA which are normally transcribed from the paternal allele in ICM cells show premature transcription at the 4C stage in maternal Dnmt3a knockout embryos. Taken together, these observations uncover an unexpected role for maternal DNMT3A activity in post-fertilization epigenetic reprogramming and transcriptional silencing of the paternal genome.
2020-08-19 | GSE141877 | GEO
Project description:While de novo DNA methylation (DNAme) in mammalian germ cells is dependent upon DNMT3A and DNMT3L, oocytes and spermatozoa show distinct patterns of DNAme. In mouse oocytes, de novo DNAme requires the lysine methyltransferase (KMTase) SETD2, which deposits H3K36me3. Surprisingly, we show here that SETD2 is dispensable for de novo DNAme in the male germline. Rather, the KMTase NSD1, which broadly deposits H3K36me2 in euchromatic regions, plays a critical role in de novo DNAme in prospermatogonia, including of imprinted genes. However, males deficient in germline NSD1 show a more severe defect in spermatogenesis than Dnmt3l-/- males. Furthermore, unlike DNMT3L, NSD1 safeguards a subset of genes against H3K27me3-associated transcriptional silencing. In contrast, H3K36me2 plays only a minor role in de novo DNAme during oogenesis and females with NSD1 deficient oocytes are fertile. Thus, the sexually dimorphic pattern of DNAme in mature mouse gametes is driven by distinct profiles of H3K36 methylation.
2020-07-10 | GSE148150 | GEO
Project description:Fully-grown oocytes are transcriptionally silent and must stably maintain mRNAs needed for oocyte meiotic maturation and early embryonic development. However, where and how mammalian oocytes store maternal mRNAs is unclear. Here, we report that mammalian oocytes accumulate mRNAs in a mitochondria-associated ribonucleoprotein domain (MARDO). MARDO assembly around mitochondria was promoted by the RNA-binding protein ZAR1, and directed by an increase in mitochondrial membrane potential during oocyte growth. MARDO foci coalesced into hydrogel-like matrices that clustered mitochondria. Maternal mRNAs stored in the MARDO were translationally repressed. Loss of ZAR1 disrupted the MARDO, dispersed mitochondria, and caused a premature loss of MARDO-localized mRNAs. Thus, a mitochondria-associated membraneless compartment controls mitochondrial distribution and regulates maternal mRNA storage, translation and decay to ensure fertility in mammals.
2022-10-25 | PXD036974 | Pride