Nucleosome occupancy of C. elegans wild-type (N2) early stage embryos vs. mature sperm from him-8(e1489) males
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ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE115705 | GEO | 2018/07/23
REPOSITORIES: GEO
Similar Datasets
Project description:Here we report that the Caenorhabditis elegans sperm genome is packaged in nucleosomes and carries a histone-based epigenetic memory of genes with spermatogenesis-restricted expression and surprisingly genes with oogenesis-enriched expression as well. In sperm, spermatogenesis genes are uniquely marked with both active and repressive marks, which may reflect a sperm-specific chromatin signature.
2018-07-23 | GSE115704 | GEO
Project description:In mature human sperm, genes of importance for embryo development (i.e. transcription factors) lack DNA methylation and bear nucleosomes with distinctive histone modifications, suggesting the specialized packaging of these developmental genes in the germline. Here, we explored the tractable zebrafish model and found conceptual conservation as well as several new features. Biochemical and mass spectrometric approaches reveal the zebrafish sperm genome packaged in nucleosomes and histone variants (and not protamine), and we find linker histones high and H4K16ac absent - key factors which may contribute to genome condensation. We examined several activating (H3K4me2/3, H3K14ac, H2AFV) and repressing (H3K27me3, H3K36me3, H3K9me3, hypoacetylation) modifications/compositions genome-wide, and find developmental genes packaged in large blocks of chromatin with coincident activating and repressing marks and DNA hypomethylation, revealing complex ‘multivalent’ chromatin. Notably, genes that acquire DNA methylation in the soma (muscle) are enriched in transcription factors for alternative cell fates. Remarkably, we find H3K36me3 located in ‘silent’ developmental gene promoters, and not present at the 3’ ends of coding regions of genes heavily transcribed during sperm maturation, suggesting different rules for H3K36me3 in the germline and soma. We also reveal the chromatin patterns of transposons, rDNA, and tRNAs. Finally, high levels of H3K4me3 and H3K14ac in sperm are correlated with genes activated in embryos prior to the mid-blastula transition (MBT), whereas multivalent genes are correlated with activation at or after MBT. Taken together, gene sets with particular functions in the embryo are packaged by distinctive types of complex and often atypical chromatin in sperm.
2011-01-13 | GSE26609 | GEO
Project description:In mature human sperm, genes of importance for embryo development (i.e. transcription factors) lack DNA methylation and bear nucleosomes with distinctive histone modifications, suggesting the specialized packaging of these developmental genes in the germline. Here, we explored the tractable zebrafish model and found conceptual conservation as well as several new features. Biochemical and mass spectrometric approaches reveal the zebrafish sperm genome packaged in nucleosomes and histone variants (and not protamine), and we find linker histones high and H4K16ac absent - key factors which may contribute to genome condensation. We examined several activating (H3K4me2/3, H3K14ac, H2AFV) and repressing (H3K27me3, H3K36me3, H3K9me3, hypoacetylation) modifications/compositions genome-wide, and find developmental genes packaged in large blocks of chromatin with coincident activating and repressing marks and DNA hypomethylation, revealing complex ‘multivalent’ chromatin. Notably, genes that acquire DNA methylation in the soma (muscle) are enriched in transcription factors for alternative cell fates. Remarkably, we find H3K36me3 located in ‘silent’ developmental gene promoters, and not present at the 3’ ends of coding regions of genes heavily transcribed during sperm maturation, suggesting different rules for H3K36me3 in the germline and soma. We also reveal the chromatin patterns of transposons, rDNA, and tRNAs. Finally, high levels of H3K4me3 and H3K14ac in sperm are correlated with genes activated in embryos prior to the mid-blastula transition (MBT), whereas multivalent genes are correlated with activation at or after MBT. Taken together, gene sets with particular functions in the embryo are packaged by distinctive types of complex and often atypical chromatin in sperm. [DNA profiling]: H3K4me3, H3K4me2, H3K14ac, H3K36me3, H3K27me3, H3K9me3, and H2AFV ChIP-chip in zebrafish sperm; DNA methylation in zebrafish sperm and muscle by MeDIP-chip. (two replicates and dye-swaps for all experiments). Antibodies: H3K4me3 (Abcam ab8580 and Active Motif 39159), H3K4me2 (Abcam ab7766), H3K14Ac (Upstate 07-353), H2AZ (Abcam ab4174), H3K27me3 (Upstate 07-449), H3K9me3 (Active Motif 39161), H3K36me3 (Abcam ab9050), 5-methylcytidine (Eurogentec BI-MECY-1000). Supplementary files: Processed data files reporting calculated enrichment log2 ratio (mean ChIP/mean Input in the log2 ratio). Note: For analysis, "mean Input" from H3K4me3-rep1 ch1, H3K4me2-rep1 ch2, and H3K36me3-rep2 ch1 for all ChIP eluates. [mRNA profiling]: Transcripts in zebrafish mature sperm using zebrafish expression microarray from Agilent. (two replicates)
2011-01-13 | E-GEOD-26609 | biostudies-arrayexpress
Project description:Mammalian embryonic stem (ES) cells and sperm exhibit unusual chromatin packaging that plays important roles in cellular function. Here, we extend a recently developed technique, based on deep paired-end sequencing of lightly digested chromatin, to assess footprints of nucleosomes and other DNA-binding proteins genome-wide in murine ES cells and sperm. In ES cells, we recover well-characterized features of chromatin such as promoter nucleosome depletion, and further identify widespread footprints of sequence-specific DNA-binding proteins such as CTCF, which we validate in knockdown studies. We document global differences in nuclease accessibility between ES cells and sperm, finding that the majority of histone retention in sperm preferentially occurs in large gene-poor genomic regions, with only a small subset of nucleosomes being retained over promoters of developmental regulators. Finally, we describe evidence that CTCF remains associated with the genome in mature sperm, where it could play a role in organizing the sperm genome. We use Micrococcal Nuclease (MNase) to map chromatin structure in mouse ES cells and sperm. Specifically, we generate paired-end deep-sequencing libraries that are able to distinguish DNA digestion products by size, thus allowing us to simultaneously map nucleosomes as well as other DNA-binding proteins such as transcription factors.
2014-07-08 | E-GEOD-58101 | biostudies-arrayexpress
Project description:To achieve the extreme nuclear condensation necessary for sperm function, most histones are replaced with protamines during spermiogenesis in mammals. Mature sperm retain only a small fraction of nucleosomes, which are, in part, enriched on gene regulatory sequences, and recent findings suggest that these retained histones provide epigenetic information that regulates expression of a subset of genes involved in embryo development after fertilization. We addressed this tantalizing hypothesis by analyzing two mouse models exhibiting abnormal histone positioning in mature sperm due to impaired poly(ADP-ribose) (PAR) metabolism during spermiogenesis and identified altered sperm histone retention in specific gene loci genome-wide using MNase digestion-based enrichment of mononucleosomal DNA. We then set out to determine the extent to which expression of these genes was altered in embryos generated with these sperm. For control sperm, most genes showed some degree of histone association, unexpectedly suggesting that histone retention in sperm genes is not an all-or-none phenomenon and that a small number of histones may remain associated with genes throughout the genome. The amount of retained histones, however, was altered in many loci when PAR metabolism was impaired. To ascertain whether sperm histone association and embryonic gene expression are linked, the transcriptome of individual 2-cell embryos derived from such sperm was determined using microarrays and RNA sequencing. Strikingly, a moderate but statistically significant portion of the genes that were differentially expressed in these embryos also showed different histone retention in the corresponding gene loci in sperm of their fathers. These findings provide new evidence for the existence of a linkage between sperm histone retention and gene expression in the embryo. Mnase sensitivity of sperm DNA, indicating nucleosomal, not protamine, packaging was altered in mice by manipulating poly(ADP-ribose) metabolism in adult males using a specific PARP inhibitor for 6 weeks. Abnormal sperm nucleosomal organization of males analyzed by these tiling arrays was compared with differential gene expression in 2 cell embryos fathered by these males analyzed by separate gene expression arrays and RNA sequencing.
2014-08-30 | E-GEOD-56282 | biostudies-arrayexpress
Project description:To achieve the extreme nuclear condensation necessary for sperm function, most histones are replaced with protamines during spermiogenesis in mammals. Mature sperm retain only a small fraction of nucleosomes, which are, in part, enriched on gene regulatory sequences, and recent findings suggest that these retained histones provide epigenetic information that regulates expression of a subset of genes involved in embryo development after fertilization. We addressed this tantalizing hypothesis by analyzing two mouse models exhibiting abnormal histone positioning in mature sperm due to impaired poly(ADP-ribose) (PAR) metabolism during spermiogenesis and identified altered sperm histone retention in specific gene loci genome-wide using MNase digestion-based enrichment of mononucleosomal DNA. We then set out to determine the extent to which expression of these genes was altered in embryos generated with these sperm. For control sperm, most genes showed some degree of histone association, unexpectedly suggesting that histone retention in sperm genes is not an all-or-none phenomenon and that a small number of histones may remain associated with genes throughout the genome. The amount of retained histones, however, was altered in many loci when PAR metabolism was impaired. To ascertain whether sperm histone association and embryonic gene expression are linked, the transcriptome of individual 2-cell embryos derived from such sperm was determined using microarrays and RNA sequencing. Strikingly, a moderate but statistically significant portion of the genes that were differentially expressed in these embryos also showed different histone retention in the corresponding gene loci in sperm of their fathers. These findings provide new evidence for the existence of a linkage between sperm histone retention and gene expression in the embryo. Mnase sensitivity of sperm DNA, indicating nucleosomal, not protamine, packaging was altered in mice by manipulating poly(ADP-ribose) metabolism in adult males using Parg gene disruption (Parg(110)-/-). Abnormal sperm nucleosomal organization of males analyzed by these tiling arrays was compared with differential gene expression in individual 2 cell embryos fathered by these males analyzed in separate expression microarrays.
2014-08-30 | E-GEOD-56281 | biostudies-arrayexpress
Project description:We have combined standard micrococcal (MNase) digestion of nuclei with a modified protocol for construction paired-end DNA sequencing libraries to map both nucleosomes and subnucleosome-sized particles at single base-pair resolution throughout the budding yeast genome. We found that partially unwrapped nucleosomes and subnucleosome-sized particles can occupy the same position within a cell population, suggesting dynamic behavior. By varying the time of MNase digestion, we have been able to observe changes that reflect differential sensitivity of particles, including eviction of nucleosomes. Our protocol and mapping method provide a general strategy for characterizing full epigenomes. We used micrococcal nuclease mapping, chromatin immunoprecipitation and paired-end sequencing to determine the structure of yeast centromeres at single base-pair resolution.
2011-10-26 | E-GEOD-30551 | biostudies-arrayexpress
Project description:Nucleosomes are the principal packaging units of chromatin and critical for gene regulation and genome stability. In mammals, a subset of nucleosomes fail to be replaced by protamines during spermatogenesis and are retained in mature spermatozoa providing opportunities for paternal epigenetic transmission. In humans, the remaining 10% localize at regulatory elements of genes. To assess evolutionary conservation and to dissect the molecular logic underlying nucleosome retention, we determined the genome wide nucleosome occupancy in mouse spermatozoa that only contain 1% residual histones. In striking contrast to mammalian somatic cells and haploid round spermatids, we observe high enrichment of nucleosomes at CpG-rich sequences throughout the genome, at conserved regulatory sequences as well as at intra- and intergenic regions and repetitive DNA. This preferred occupancy occurs mutually exclusive with DNA methylation both in mouse and human sperm. At unmethylated CpG-rich sequences, residing nucleosomes are largely composed of the H3.3 histone variant, and trimethylated at lysine 4 (H3K4me3). Both canonical H3.1/H3.2 and H3.3 variant histones are present at promoters marked by Polycomb-mediated H3K27me3, which is strongly predictive for gene repression in pre-implantation embryos. Our data indicate important roles of DNA sequence composition, DNA methylation, variant H3.3 and canonical H3.1/H3.2 histones and associated modifications in nucleosome retention versus eviction during the histone-to-protamine remodeling process in elongating spermatids and potentially in epigenetic inheritance by nucleosomes between generations. Identification of histone, histone variant and histone modification states in round spermatids and sperm
2013-06-15 | E-GEOD-42629 | biostudies-arrayexpress
Project description:To achieve the extreme nuclear condensation necessary for sperm function, most histones are replaced with protamines during spermiogenesis in mammals. Mature sperm retain only a small fraction of nucleosomes, which are, in part, enriched on gene regulatory sequences, and recent findings suggest that these retained histones provide epigenetic information that regulates expression of a subset of genes involved in embryo development after fertilization. We addressed this tantalizing hypothesis by analyzing two mouse models exhibiting abnormal histone positioning in mature sperm due to impaired poly(ADP-ribose) (PAR) metabolism during spermiogenesis and identified altered sperm histone retention in specific gene loci genome-wide using MNase digestion-based enrichment of mononucleosomal DNA. We then set out to determine the extent to which expression of these genes was altered in embryos generated with these sperm. For control sperm, most genes showed some degree of histone association, unexpectedly suggesting that histone retention in sperm genes is not an all-or-none phenomenon and that a small number of histones may remain associated with genes throughout the genome. The amount of retained histones, however, was altered in many loci when PAR metabolism was impaired. To ascertain whether sperm histone association and embryonic gene expression are linked, the transcriptome of individual 2-cell embryos derived from such sperm was determined using microarrays and RNA sequencing. Strikingly, a moderate but statistically significant portion of the genes that were differentially expressed in these embryos also showed different histone retention in the corresponding gene loci in sperm of their fathers. These findings provide new evidence for the existence of a linkage between sperm histone retention and gene expression in the embryo. 9 WT samples in 3 groups of 3. Each group consists of 3 eggs fertilized by the same father. 9 KO samples in the same setup. Samples are single 2-cell embryos. All mice are in a 129SVE (=129S6/SvEvTac, Taconic) background.
2014-08-30 | E-GEOD-56184 | biostudies-arrayexpress