Conservation and divergence of DNA methylation patterns and functions in vertebrates
Ontology highlight
ABSTRACT:
ORGANISM(S): Bos taurus Mus musculus Canis lupus familiaris Gallus gallus Homo sapiens Oryctolagus cuniculus Sus scrofa
PROVIDER: GSE175615 | GEO | 2022/03/23
REPOSITORIES: GEO
Similar Datasets
Project description:Cytosine DNA methylation is a heritable epigenetic mark present in many eukaryotic organisms. While DNA methylation likely has a conserved role in gene silencing, the levels and patterns of DNA methylation appear to vary drastically among different organisms. Here, we used shotgun genomic bisulfite sequencing (BS-Seq) to compare DNA methylation in eight diverse plant and animal genomes. We found that patterns of methylation are very similar in flowering plants with methylated cytosines detected in all sequence contexts, whereas CG methylation predominates in animals. Vertebrates have methylation throughout the genome except for CpG islands. Gene body methylation is conserved with clear preference for exons in most of the organisms. Furthermore, genes appear to be the major target of methylation in Ciona and honeybee. Among the eight organisms, the green alga Chlamydomonas has the most unusual pattern of methylation, having non-CG methylation enriched in exons of genes rather than in repeats and transposons. In addition, we demonstrate that the Dnmt1 cofactor Uhrf1 has a conserved function in maintaining CG methylation in both transposons and gene bodies in the mouse, Arabidopsis, and zebrafish genomes. Comparison of methylation across eight eukaryotic organisms
2010-04-09 | E-GEOD-21152 | biostudies-arrayexpress
Project description:Cytosine DNA methylation is a heritable epigenetic mark present in many eukaryotic organisms. While DNA methylation likely has a conserved role in gene silencing, the levels and patterns of DNA methylation appear to vary drastically among different organisms. Here, we used shotgun genomic bisulfite sequencing (BS-Seq) to compare DNA methylation in eight diverse plant and animal genomes. We found that patterns of methylation are very similar in flowering plants with methylated cytosines detected in all sequence contexts, whereas CG methylation predominates in animals. Vertebrates have methylation throughout the genome except for CpG islands. Gene body methylation is conserved with clear preference for exons in most of the organisms. Furthermore, genes appear to be the major target of methylation in Ciona and honeybee. Among the eight organisms, the green alga Chlamydomonas has the most unusual pattern of methylation, having non-CG methylation enriched in exons of genes rather than in repeats and transposons. In addition, we demonstrate that the Dnmt1 cofactor Uhrf1 has a conserved function in maintaining CG methylation in both transposons and gene bodies in the mouse, Arabidopsis, and zebrafish genomes.
2010-04-09 | GSE21152 | GEO
Project description:Two-thirds of gene promoters in mammals are associated with regions of non-methylated DNA, called CpG islands (CGIs), which counteract the repressive effects of DNA methylation. In lower vertebrates, computational CGI predictions often reside away from gene promoters, suggesting a major divergence in gene promoter architecture across vertebrates. By experimentally identifying non-methylated DNA in the genomes of seven diverse vertebrates, we instead reveal that non-methylated islands (NMIs) of DNA are a central feature of vertebrate gene promoters. Furthermore, NMIs are present at orthologous genes across vast evolutionary distances, revealing a surprising level of conservation in this epigenetic feature. By profiling NMIs in different tissues and developmental stages we uncover a unifying set of features that are central to the function of NMIs in vertebrates. Together these findings demonstrate an ancient logic for NMI usage at gene promoters and reveal an unprecedented level of epigenetic conservation across vertebrate evolution. Bio-CAP was used to identify non-methylated regions of the genome in seven diverse vertebrates (human, mouse, platypus, chicken, lizard, frog and zebrafish) across a number of tissues.
2013-01-22 | E-GEOD-43512 | biostudies-arrayexpress
Project description:Conservation and divergence of DNA methylation patterns and functions in vertebrates
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Project description:To explore how parental epigenetic information is transmitted to the next generation across mammals, we systematically investigated the epigenomes of oocytes and early embryos among human, bovine, porcine, rat, and mouse. This unprecedented dataset revealed strikingly diverse, species-specific innovation of epigenetic transition. In oocytes, DNA methylation is restricted to active gene bodies in rodents, allowing methylation of maternal imprints but not intergenic paternal imprints. Strikingly, hypermethylation also occurs in non-transcribed regions in porcine and bovine, where paternal imprints instead reside in hypomethylated, megabase-long “CpG continents (CGCs)”. Despite the presence of H3K4me3 and H3K27me3 domains in non-human oocytes, only rodent H3K27me3 survives beyond genome activation, supporting H3K27me3-mediated imprinting. Coincidently, regulatory elements are segregated away from H3K27me3 domains, the ectopic invasion of which leads to aberrant embryonic transcription. Finally, human does not fully resemble any of the rest species. Hence, mammals invent diverse epigenetic inheritance and reprogramming which center around a delicate balance in establishing imprints while protecting other regulatory regions.
2021-11-26 | GSE163620 | GEO
Project description:Accelerated evolution of any portion of the genome is of significant interest, potentially signaling positive selection of phenotypic traits and adaptation. Accelerated evolution remains understudied for structured RNAs, despite the fact that an RNA's structure is often key to its function. RNA structures are typically characterized by compensatory (structure-preserving) basepair changes that are unexpected given the underlying sequence variation, i.e., they have evolved through negative selection on structure. We address the question of how fast the primary sequence of an RNA can change through evolution while conserving its structure. Specifically, we consider predicted and known structures in vertebrate genomes. After careful control of false discovery rates, we obtain 13 de novo structures (and three known Rfam structures) that we predict to have rapidly evolving sequences-defined as structures where the primary sequences of human and mouse have diverged at least twice as fast (1.5 times for Rfam) as nearby neutrally evolving sequences. Two of the three known structures function in translation inhibition related to infection and immune response. We conclude that rapid sequence divergence does not preclude RNA structure conservation in vertebrates, although these events are relatively rare.
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Project description:The complexity of the maize (Zea mays) genome makes it an ideal system for the study of both genetics and epigenetics. Here, we generated the integrated maps of transcriptomes and epigenomes of shoots and roots of two maize inbred lines and their reciprocal hybrids, and globally surveyed the epigenetic variations and their relationships with transcriptional divergence between different tissues and different genotypes. We observed that whereas histone modifications vary both between tissues and between genotypes, DNA methylation patterns are more distinguishable between genotypes than between tissues. Histone modifications were associated with transcriptomic divergence between tissues and between hybrids and parents. Further, we show that genes up-regulated in both shoots and roots of hybrids were significantly enriched in the nucleosome assembly pathway. Interestingly, 22- and 24-nt siRNAs were shown to be derived from distinct transposable elements (TEs), and for different TEs in both shoots and roots, the differences in siRNA activity between hybrids and patents were primarily driven by different siRNA species. Together, our results suggest that despite of the variations in specific genes or genomic loci, similar mechanisms may account for the genome-wide epigenetic regulation of gene activity and transposon stability in different tissues of maize hybrids. Genome-wide integrated maps of mRNA and small RNA (sRNA) transcriptomes, DNA methylomes and genome-wide distribution of three representative histone modifications (H3K4me3, H3K9ac and H3K36me3) in the shoots and roots of 14 day old seedlings of two maize inbred lines (B73 and Mo17) and their reciprocal hybrids (B73 x Mo17 and Mo17 x B73).
2013-03-19 | E-GEOD-43142 | biostudies-arrayexpress
Project description:Mitochondrial heteroplasmy, the presence of more than one mtDNA variant in a cell or individual is not as uncommon as previously thought. It is mostly due to the high mutation rate of the mtDNA and limited repair mechanisms present in the mitochondrion. The phenomenon has been studied mostly in human samples and in medical contexts. Heteroplasmy has also been researched in other species in fields such as forensics or genetic foot printing, but these studies usually focused on contained families within closely related species. Here we describe a large cross-species evaluation of heteroplasmy in mammals. We employed a novel approach to detect mitochondrial heteroplasmy in both novel and previously reported ChIP-sequencing datasets, which include concomitant mitochondrial DNA sequenced in the experiment. Here, we report novel ChIP-seq experiments for H3K4me1 and CEBPA across mammals, as well as some H3K4me3, H3K27ac and total histone H3 experiments. Most of the reported CEBPA experiments are good quality pull-downs, however the quality of many of the other experiments reported here has not been interrogated in detail. Whereas this does not affect the investigation of mitochondrial DNA pollution for the purposes of this study, both H3K4me1 and total histone H3 ChIP-seq datasets were often sequenced to relatively low depth and showed low ChIP enrichment compared to the other antibodies.
2016-05-13 | E-MTAB-3933 | biostudies-arrayexpress
Project description:The complexity of the maize (Zea mays) genome makes it an ideal system for the study of both genetics and epigenetics. Here, we generated the integrated maps of transcriptomes and epigenomes of shoots and roots of two maize inbred lines and their reciprocal hybrids, and globally surveyed the epigenetic variations and their relationships with transcriptional divergence between different tissues and different genotypes. We observed that whereas histone modifications vary both between tissues and between genotypes, DNA methylation patterns are more distinguishable between genotypes than between tissues. Histone modifications were associated with transcriptomic divergence between tissues and between hybrids and parents. Further, we show that genes up-regulated in both shoots and roots of hybrids were significantly enriched in the nucleosome assembly pathway. Interestingly, 22- and 24-nt siRNAs were shown to be derived from distinct transposable elements (TEs), and for different TEs in both shoots and roots, the differences in siRNA activity between hybrids and patents were primarily driven by different siRNA species. Together, our results suggest that despite of the variations in specific genes or genomic loci, similar mechanisms may account for the genome-wide epigenetic regulation of gene activity and transposon stability in different tissues of maize hybrids.
2013-03-19 | GSE43142 | GEO
Project description:Two-thirds of gene promoters in mammals are associated with regions of non-methylated DNA, called CpG islands (CGIs), which counteract the repressive effects of DNA methylation. In lower vertebrates, computational CGI predictions often reside away from gene promoters, suggesting a major divergence in gene promoter architecture across vertebrates. By experimentally identifying non-methylated DNA in the genomes of seven diverse vertebrates, we instead reveal that non-methylated islands (NMIs) of DNA are a central feature of vertebrate gene promoters. Furthermore, NMIs are present at orthologous genes across vast evolutionary distances, revealing a surprising level of conservation in this epigenetic feature. By profiling NMIs in different tissues and developmental stages we uncover a unifying set of features that are central to the function of NMIs in vertebrates. Together these findings demonstrate an ancient logic for NMI usage at gene promoters and reveal an unprecedented level of epigenetic conservation across vertebrate evolution.
2013-01-22 | GSE43512 | GEO