Discovery and capture of novel dynamic DNA methylation in human sperm with preferential links to altered folate metabolism
Ontology highlight
ABSTRACT:
PROVIDER: EGAS00001003617 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Previous studies have suggested an erasure of DNA methylation is required to develop the stem cells in the morula embryo. An exception involves imprinted genes that escape this DNA methylation erasure. Transgenerational differential DNA methylation regions (DMRs) have been speculated to also escape this erasure. The current study was designed to assess if morula embryos escape erasure of DDT (dichloro-diphenyl-trichloroethane)-induced transgenerational sperm DMRs. Observations demonstrate that the transgenerational sperm DMR sites are not erased, so are imprinted-like DMR sites. Interestingly, we also found that the majority of low-density CpG genomic sites had a significant increase in DNA methylation in the morula embryo compared to sperm. The general erasure of DNA methylation during embryogenesis appears applicable for high-density CpG islands, but not low-density CpG deserts.
2022-11-10 | GSE211135 | GEO
Project description:Numerous health consequences of tobacco smoke exposure have been characterized, and the effects of smoking on traditional measures of male fertility are well described. However, a growing body of data indicates that pre‐conception paternal smoking also confers increased risk for a number of morbidities on offspring. The mechanism for this increased risk has not been elucidated, but it is likely mediated, at least in part, through epigenetic modifications transmitted through spermatozoa. In this study, we investigated the impact of cigarette smoke exposure on sperm DNA methylation patterns in 78 men who smoke and 78 never‐smokers using the Infinium Human Methylation 450 beadchip. We investigated two models of DNA methylation alterations: (i) consistently altered methylation at specific CpGs or within specific genomic regions and (ii) stochastic DNA methylation alterations manifest as increased variability in genome‐wide methylation patterns in men who smoke. We identified 141 significantly differentially methylated CpGs associated with smoking. In addition, we identified a trend toward increased variance in methylation patterns genome‐wide in sperm DNA from men who smoke compared with never‐smokers. These findings of widespread DNA methylation alterations are consistent with the broad range of offspring heath disparities associated with pre‐conception paternal smoke exposure and warrant further investigation to identify the specific mechanism by which sperm DNA methylation perturbation confers risk to offspring health and whether these changes can be transmitted to offspring and transgenerationally.
2018-05-23 | GSE114753 | GEO
Project description:Age-dependent modifications of the germ cells epigenome remain poorly understood. Our objective was to assess the DNA methylation profile of human spermatozoa during aging. A cohort study was designed to investigate the effects of age and fertility status on sperm DNA methylation.
| EGAS00001004168 | EGA
Project description:The pre and postnatal environment can affect both an individual’s risk of adult onset metabolic disease and that of subsequent generations. Although animal models and epidemiological data implicate epigenetic inheritance, little is known of the mechanisms involved. In a robust intergenerational model of developmental programming we demonstrate that the nutritional environment experienced in utero by F1 generation embryos alters the DNA methylome of the F1 adult male germ line in a locus-specific manner, without affecting overall methylation levels. Differentially methylated regions are mostly hypomethylated and are enriched in nucleosome retaining regions in adult sperm. A substantial fraction is resistant to early embryo methylation reprogramming, and thus have the potential to alter F2 generation development. Altered expression of transcripts neighbouring differentially methylated regions are evident in tissues of F2 offspring despite lack of persistence of differential methylation. Transmitted methylation variation in the germline at key regulatory loci may therefore contribute to the development of metabolic disease in the subsequent generation. 2 biological replicates of pooled sperm samples for each control (C) or undernutrition (UN) model
2014-07-16 | E-GEOD-58747 | biostudies-arrayexpress
Project description:A father’s lifetime experiences can be transmitted to his offspring to affect health and development. The mechanisms underlying paternal epigenetic transmission are unclear. Unlike somatic cells, there are few nucleosomes in sperm and their function in epigenetic inheritance is unknown. We generated transgenic mice in which overexpression of the histone H3 lysine 4 (H3K4) demethylase LSD1/KDM1A during spermatogenesis reduced H3K4 dimethylation in sperm. KDM1A overexpression in one generation severely impaired development and survivability of offspring. These defects persisted transgenerationally in the absence of KDM1A germ line expression and were associated with altered RNA profiles in sperm and offspring. We show that epigenetic inheritance of aberrant development can be initiated by histone demethylase activity in developing sperm, without changes to DNA methylation at CpG-rich regions.
2015-10-08 | GSE66050 | GEO
Project description:5-methylcytosine is a major epigenetic modification sometimes called "the fifth nucleotide". However, our knowledge of how offspring inherit the DNA methylome from parents is limited. We generated nine single-base resolution DNA methylomes including zebrafish gametes and early embryos. The oocyte methylome is significantly hypo-methylated compared to sperm. Strikingly, the paternal DNA methylation pattern is maintained throughout early embryogenesis. The maternal DNA methylation pattern is maintained until the 16-cell stage. Then, the oocyte methylome is gradually discarded through cell division, and progressively reprogrammed to a pattern similar to that of the sperm methylome. The passive demethylation rate and the de novo methylation rate are similar in the maternal DNA. By the midblastula stage, the embryo?s methylome is virtually identical to the sperm methylome. Moreover, inheritance of the sperm methylome facilitates the epigenetic regulation of embryogenesis. Therefore, besides DNA sequences, sperm DNA methylome is also inherited in zebrafish early embryos.
2013-05-20 | GSE44075 | GEO
Project description:5-methylcytosine is a major epigenetic modification sometimes called "the fifth nucleotide". However, our knowledge of how offspring inherit the DNA methylome from parents is limited. We generated nine single-base resolution DNA methylomes including zebrafish gametes and early embryos. The oocyte methylome is significantly hypo-methylated compared to sperm. Strikingly, the paternal DNA methylation pattern is maintained throughout early embryogenesis. The maternal DNA methylation pattern is maintained until the 16-cell stage. Then, the oocyte methylome is gradually discarded through cell division, and progressively reprogrammed to a pattern similar to that of the sperm methylome. The passive demethylation rate and the de novo methylation rate are similar in the maternal DNA. By the midblastula stage, the embryo?s methylome is virtually identical to the sperm methylome. Moreover, inheritance of the sperm methylome facilitates the epigenetic regulation of embryogenesis. Therefore, besides DNA sequences, sperm DNA methylome is also inherited in zebrafish early embryos. hMeDIP-seq is performed in sperm,2-cell,16-cell,1k-cell and a input control sample 4 new samples are added to GSE44075. RNA-seq is performed in sperm, egg,1k-cell, germring samples .hMeDIP-seq is performed in sperm,2-cell,16-cell,1k-cell and a input control sample 10 new samples are added to GSE44075. Bisulfite-seq is performed for nine samples : sperm, egg,16-cell,32-cell,64-cell,128-cell,1k-cell , Germring and testis. TAB-seq is performed for one sample , 32-cell.
2013-05-20 | E-GEOD-44075 | biostudies-arrayexpress
Project description:The WGBS data was published in PMID: 31393794 and the sequencing data from WGBS and MCC-Seq have been submitted to the European Genome-phenome Archive under the accession number EGAS00001003617. The paternal environment including stress, diet and toxicants has been linked to infertility and negative outcomes for offspring such as birth defects and adult onset of disease. Such effects may be transmitted via sperm through epigenetic mechanisms. To date, in depth profiling of the sperm epigenome in men has been limited. Our objective was to characterize the sperm profile of histone H3 lysine 4 tri-methylation (H3K4me3) from a reference population of men and relate this to sperm DNA methylation. ChIP-seq targeting H3K4me3 was performed on sperm from a representative reference population of 30 men and then overlapped with whole genome bisulfite sequencing (WGBS) data from the same men. Our analysis revealed that H3K4me3 is localized throughout the genome and at genes for fertility and development. Remarkably, enrichment was also found at regions that escape epigenetic reprogramming in primordial germ cells, embryonic enhancers and SINEs. The level of H3K4me3 in sperm associates with the degree of gene expression in embryo development. We find significant overlap in H3K4me3 and DNA methylation throughout the genome suggesting potential for the development of a personalized medicine approach for the assessment of fertility, lifestyle and environmental exposures.
2021-07-20 | GSE156108 | GEO
Project description:BACKGROUND: In previous studies using candidate gene approaches, low sperm count (oligospermia) has been associated with altered sperm mRNA content and DNA methylation in both imprinted and non-imprinted genes. We performed a genome-wide analysis of sperm DNA methylation and mRNA content to test for associations with sperm function. METHODS AND RESULTS: Sperm DNA and mRNA were isolated from 21 men with a range of semen parameters presenting to a tertiary male reproductive health clinic. DNA methylation was measured with the Illumina Infinium array at 27,000 CpG loci. Unsupervised clustering of methylation data differentiated the 21 sperm samples by their motility values. Recursively partitioned mixture modeling (RPMM) of methylation data resulted in four distinct methylation profiles that were significantly associated with sperm motility (P=0.01). Linear models of microarray analysis (LIMMA) was performed based on motility and identified 9,189 CpG loci with significantly altered methylation (Q<0.05) in the low motility samples, with many loci located in genes associated with subfertility and epigenetic regulation. In the low motility samples, the majority of disrupted CpG loci (80%) were hypomethylated. Of the aberrantly methylated CpGs, 194 were associated with imprinted genes almost equally distributed into hypermethylated (predominantly paternally expressed) and hypomethylated (predominantly maternally expressed) groups. Sperm mRNA was measured with the Human Gene 1.0 ST Affymetrix GeneChip Array. LIMMA analysis based on motility identified 20 candidate transcripts as differentially expressed in low motility sperm, including HDAC1 (NCBI 3065), SIRT3 (NCBI 23410), and DNMT3A (NCBI 1788). Altered expression of these epigenetic regulatory genes was associated with RPMM DNA methylation class. CONCLUSIONS: Using integrative genome-wide approaches to study epigenetic and gene expression patterns in human sperm we identified CpG methylation profiles and mRNA alterations associated with low sperm motility, and that low motility sperm may have aberrant genome-wide hypomethylation due to excess HDAC1 activity. See summary above
2011-06-02 | E-GEOD-26974 | 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