Sequencing and genome-wide mapping of 146 bp mono-nucleosomal DNA from human and bovine sperm
Ontology highlight
ABSTRACT:
ORGANISM(S): Bos taurus Homo sapiens
PROVIDER: GSE47843 | GEO | 2014/07/08
SECONDARY ACCESSION(S): PRJNA208076
REPOSITORIES: GEO
Similar Datasets
Project description:The phenomenon of nucleosome retention in mammalian sperm chromatin is still not clarified yet. The goal of our study was to characterize the binding sites of sperm nucleosomes in the human and bovine genomes, and through this, to clarify whether nucleosome retention in sperm underlies rules of great generality and has a biological function. Comparing two mammalian systems we found that nucleosomes remain mainly in centromeres and in non-coding intergenic and intron regions. In contrast, coding DNA, promoter regions and transcription start and end sites, especially in homeobox genes and in the majority of genes with relevance for organ development and morphogenesis, were nucleosome-free. 146 bp mono-nucleosomal DNA was isolated and purified from sperm samples of two fertile bulls (bos taurus), one fertile man and a pool of four fertile donors; each DNA sample was deep sequenced using Illumina GAIIx and genome-wide mapped on respective genome; nucleosome-binding sites were analyzed in a genome-wide comparative manner.
2014-07-08 | E-GEOD-47843 | biostudies-arrayexpress
Project description:During mammalian spermatogenesis, male germ cells undergo dramatic reorganization of chromatin, whereby 90-99% of histones are evicted and replaced by protamines. This reorganization prominently features histone acetylation to loosen chromatin structure. Given the potential role of retained histones in fertility and early embryonic development, the genomic location of retained nucleosomes is of great interest. However, the ultimate position and mechanisms underlying nucleosome eviction/retention are poorly understood, including several studies utilizing MNase-seq methodologies, but reporting remarkably dissimilar locations. Here, we utilized ATAC-seq to determine the location of retained nucleosomes in mouse sperm and found enrichment at promoters, but also retention at inter- and intragenic regions, and repetitive elements. We further investigated nucleosome eviction/retention by generating pre-meiotic, germ cell specific, conditional knockout mice for the histone acetyltransferase Gcn5, a key histone acetyltransferase. Gcn5cKO germ cells exhibited abnormal chromatin dynamics during spermiogenesis, including diminished nucleosome eviction leading to increased histone retention in sperm. These mice exhibited severe reproductive phenotypes: abnormal sperm production, sperm morphology, and ultimately, male infertility. Our findings demonstrate Gcn5 mediated histone acetylation promotes chromatin accessibility and nucleosome eviction in spermiogenesis, and that loss of histone acetylation leads to defects that disrupt male fertility and potentially, early embryogenesis.
2019-11-07 | GSE134825 | GEO
Project description:During mammalian spermatogenesis, male germ cells undergo dramatic reorganization of chromatin, whereby 90-99% of histones are evicted and replaced by protamines. This reorganization prominently features histone acetylation to loosen chromatin structure. Given the potential role of retained histones in fertility and early embryonic development, the genomic location of retained nucleosomes is of great interest. However, the ultimate position and mechanisms underlying nucleosome eviction/retention are poorly understood, including several studies utilizing MNase-seq methodologies, but reporting remarkably dissimilar locations. Here, we utilized ATAC-seq to determine the location of retained nucleosomes in mouse sperm and found enrichment at promoters, but also retention at inter- and intragenic regions, and repetitive elements. We further investigated nucleosome eviction/retention by generating pre-meiotic, germ cell specific, conditional knockout mice for the histone acetyltransferase Gcn5, a key histone acetyltransferase. Gcn5cKO germ cells exhibited abnormal chromatin dynamics during spermiogenesis, including diminished nucleosome eviction leading to increased histone retention in sperm. These mice exhibited severe reproductive phenotypes: abnormal sperm production, sperm morphology, and ultimately, male infertility. Our findings demonstrate Gcn5 mediated histone acetylation promotes chromatin accessibility and nucleosome eviction in spermiogenesis, and that loss of histone acetylation leads to defects that disrupt male fertility and potentially, early embryogenesis.
2019-11-07 | GSE134560 | GEO
Project description:During mammalian spermatogenesis, male germ cells undergo dramatic reorganization of chromatin, whereby 90-99% of histones are evicted and replaced by protamines. This reorganization prominently features histone acetylation to loosen chromatin structure. Given the potential role of retained histones in fertility and early embryonic development, the genomic location of retained nucleosomes is of great interest. However, the ultimate position and mechanisms underlying nucleosome eviction/retention are poorly understood, including several studies utilizing MNase-seq methodologies, but reporting remarkably dissimilar locations. Here, we utilized ATAC-seq to determine the location of retained nucleosomes in mouse sperm and found enrichment at promoters, but also retention at inter- and intragenic regions, and repetitive elements. We further investigated nucleosome eviction/retention by generating pre-meiotic, germ cell specific, conditional knockout mice for the histone acetyltransferase Gcn5, a key histone acetyltransferase. Gcn5cKO germ cells exhibited abnormal chromatin dynamics during spermiogenesis, including diminished nucleosome eviction leading to increased histone retention in sperm. These mice exhibited severe reproductive phenotypes: abnormal sperm production, sperm morphology, and ultimately, male infertility. Our findings demonstrate Gcn5 mediated histone acetylation promotes chromatin accessibility and nucleosome eviction in spermiogenesis, and that loss of histone acetylation leads to defects that disrupt male fertility and potentially, early embryogenesis.
2019-11-07 | GSE134521 | GEO
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: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: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.
2014-07-08 | GSE58101 | GEO
Project description:One elusive aspect of the chromosome architecture is how it constrains the DNA topology. Nucleosomes stabilise negative DNA supercoils by restraining a DNA linking number difference (∆Lk) of about -1.26. However, whether this capacity is uniform across the genome is unknown. Here, we calculated the ∆Lk restrained by over 4000 nucleosomes in yeast cells. To achieve this, we placed each nucleosome in a circular minichromosome and performed Topo-seq, a high-throughput procedure to inspect the topology of circular DNA libraries in one gel electrophoresis. We found that nucleosomes inherently restrain distinct ∆Lk values depending on their genomic origin. Nucleosome DNA topologies differ at gene bodies (∆Lk=-1.29), intergenic regions (∆Lk=-1.23), rDNA genes (∆Lk=-1.24) and telomeric regions (∆Lk=-1.07). Nucleosomes near the transcription start and termination sites also exhibit singular DNA topologies. Our findings demonstrate that nucleosome DNA topology is imprinted by its native chromatin context and persists when the nucleosome is relocated.
2023-06-05 | GSE228623 | GEO
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.
2013-06-15 | GSE42629 | GEO
Project description:In the yeast genome, a large proportion of nucleosomes occupy well-defined positions. While the contribution of chromatin remodelers and DNA binding proteins to maintain this organization is well established, the relevance of the DNA sequence to nucleosome positioning in the genomic context remains controversial. Through genome-wide, quantitative analysis of nucleosome positioning and high-resolution mutagenenesis of mononucleosomal DNA, we show that sequence changes distort the nucleosomal pattern at the level of individual nucleosomes. This effect is equally detected in transcribed and non-transcribed regions, suggesting the existence of sequence elements contributing to positioning. To identify such elements, we incorporated information from nucleosomal signatures into artificial synthetic DNA molecules and found that they generated regular nucleosomal arrays indistinguishable from those of endogenous sequences. Strikingly, this information is species-specific and can be combined with coding information through the use of synonymous codons such that genes from one species can be engineered to adopt the nucleosomal organization of another. These findings open up the possibility of designing coding and non-coding DNA molecules capable of directing their own nucleosomal organization.
2016-09-20 | GSE84910 | GEO