Base-resolution detection of N4-methylcytosine in genomic DNA using 4mC-TAB-seq
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ABSTRACT:
ORGANISM(S): synthetic construct Caldicellulosiruptor acetigenus
PROVIDER: GSE63371 | GEO | 2015/07/11
SECONDARY ACCESSION(S): PRJNA267586
REPOSITORIES: GEO
Similar Datasets
Project description:N4-methylcytosine is a major DNA modification integral to restriction-modification (R-M) systems in bacterial genomes. Here we describe 4mC-Tet-Assisted Bisulfite-sequencing (4mC-TAB-seq), a method that accurately and rapidly reveals the genome-wide locations of N4-methylcytosines at single-base resolution. By coupling Tet-mediated oxidation with a modified sodium bisulfite conversion reaction, unmodified cytosines and 5-methylcytosines are read out as thymines, whereas N4-methylcytosines are read out as cytosines revealing their positions throughout the genome. 4mC-TAB-seq
2015-07-11 | E-GEOD-63371 | biostudies-arrayexpress
Project description:Base-resolution detection of N4-methylcytosine in genomic DNA using 4mC-TAB-seq
| PRJNA267586 | ENA
Project description:N 4-methylcytosine (4mC) is a natural DNA modification occurring in thermophiles and plays important roles in restriction-modification (R-M) systems in bacterial genomes. However, the precise location and sequence context of 4mC in the whole genome are limited. In this study, we developed an APOBEC3A-mediated deamination sequencing (4mC-AMD-seq) method for genome-wide mapping of 4mC at single-base resolution. In the 4mC-AMD-seq method, cytosine and 5-methylcytosine (5mC) are deaminated by APOBEC3A (A3A) protein to generate uracil and thymine, both of which are read as thymine in sequencing, while 4mC is resistant to deamination and therefore read as cytosine. Thus, the readouts of cytosines from sequencing could manifest the original 4mC sites in genomes. With the 4mC-AMD-seq method, we achieved the genome-wide mapping of 4mC in Deinococcus radiodurans (D. radiodurans). In addition, we confirmed that 4mC, but not 5mC, was the major modification in the D. radiodurans genome. We identified 1586 4mC sites in the genome of D. radiodurans, among which 564 sites were located in the CCGCGG motif. The average methylation levels in the CCGCGG motif and non-CCGCGG sequence were 70.0% and 22.8%, respectively. We envision that the 4mC-AMD-seq method will facilitate the investigation of 4mC functions, including the 4mC-involved R-M systems, in uncharacterized but potentially useful strains.
2021-12-15 | GSE189965 | GEO
Project description:5-hydroxymethylcytosine (5hmC), an oxidized derivative of 5-methylcytosine (5mC), has been implicated as an important epigenetic regulator of mammalian development. Current procedures use cost-prohibitive DNA sequencing methods to discriminate 5hmC from 5mC, limiting their accessibility to the scientific community. Here we report a method that combines TET-assisted bisulfite conversion with Illumina 450K DNA methylation arrays for a low-cost high-throughput approach that distinguishes 5hmC and 5mC signals. Implementing this approach, termed TAB-array, we assessed DNA methylation dynamics in the differentiation of human pluripotent stem cells into cardiovascular and neural progenitors. With the ability to discriminate 5mC and 5hmC, we found a much larger number of dynamically methylated genomic regions implicated in the development of these lineages than we could detect by 5mC analysis alone. The increased resolution and accuracy afforded by this approach provides a powerful means to investigate the distinct contributions of 5mC and 5hmC in human development and disease. We generated illumina 450k DNA methylation data for a total of 9 sample groups with two biological replicates for each group. Data for 4/9 groups were generated from glucosylated and bisulfite converted DNA, from human induced plurupotent stem cells (hIPSCs), differentiated cardiovascular progenitors (CVPs), differentiated neural progenitors (NPCs), and fibroblasts. Data for the next 4/9 groups were generated from glucosylated, TET-oxidized and bisulfite converted DNA, from and included replicates of hIPSCs, CVPs, NPCs, and fibroblasts. Data for the last group was generated from standard bisulfite converted DNA (not glucosylated) from fibroblasts.
2014-12-12 | E-GEOD-60225 | biostudies-arrayexpress
Project description:DNA methylation is a key mechanism for regulation of DNA repair, DNA replication, and gene expression. In bacteria, DNA is modified by methylation on C5-cytosine (5mC), N6-adenine (6mA) and N4-cytosine (4mC). Metazoans were thought to only use 5mC to regulate gene expression until the recent discovery of N6-adenine methylation in DNA of diverse metazoan species, including mammals. Here we show by dot blot, immunoprecipitation with 4mC-specific antibodies, and ultra-high performance liquid chromatography coupled with triple-quadrupole mass spectrometry that 4mC also occurs in most eukaryotes. We further characterize 4mC sites on a near genome-wide scale by single molecule real time (SMRT) sequencing in the nematode C. elegans. In C. elegans, 4mC is found in all chromosomes but is relatively sparse on the X chromosome. 4mC is relatively enriched on introns, depleted on exons, and co-localizes with 6mA. In human cells, 4mC is anti-correlated with 5mC. Moreover, 4mC modifications are associated with increased gene expression. Transfection of human cells with a 4mC-modified luciferase reporter plasmid increases luciferase expression as compared to the unmethylated plasmid. These data suggest that 4mC promotes gene transcription, playing an opposing role to 5mC, which generally represses transcription. Thus 4mC modification of DNA is a previously unrecognized mechanism of gene regulation in eukaryotes, providing evidence for a complex epigenetic DNA code.
2018-09-01 | GSE86993 | GEO
Project description:Flavobacterium sp. TAB 87 Genome sequencing and assembly
| PRJNA297146 | ENA
Project description:5-hydroxymethylcytosine (5hmC), an oxidized derivative of 5-methylcytosine (5mC), has been implicated as an important epigenetic regulator of mammalian development. Current procedures use cost-prohibitive DNA sequencing methods to discriminate 5hmC from 5mC, limiting their accessibility to the scientific community. Here we report a method that combines TET-assisted bisulfite conversion with Illumina 450K DNA methylation arrays for a low-cost high-throughput approach that distinguishes 5hmC and 5mC signals. Implementing this approach, termed TAB-array, we assessed DNA methylation dynamics in the differentiation of human pluripotent stem cells into cardiovascular and neural progenitors. With the ability to discriminate 5mC and 5hmC, we found a much larger number of dynamically methylated genomic regions implicated in the development of these lineages than we could detect by 5mC analysis alone. The increased resolution and accuracy afforded by this approach provides a powerful means to investigate the distinct contributions of 5mC and 5hmC in human development and disease.
2014-12-12 | GSE60225 | GEO
Project description:Methylation of cytosines at the 5th carbon position of the aromatic ring has long been regarded as the predominant type of DNA base modification in eukaryotes. Often called “the fifth base”, C5-methylcytosine (5mC) plays an important role in genome defense against mobile genetic elements, and is mostly associated with transcriptional silencing, establishment of the closed chromatin configuration, and repressive histone modifications. Recently, another type of DNA modification, N6-methyladenine (6mA), has been added to the repertoire of modified bases in eukaryotic DNA, and was mostly linked to elevated transcription levels. In prokaryotes, 5mC and 6mA typically constitute components of restriction-modification (R-M) systems, along with N4-methylcytosine (4mC), which so far has been confined to bacteria. Here we report the first case of 4mC occurrence in eukaryotic DNA. We find that bdelloid rotifers, small freshwater invertebrates known for their ability to reproduce clonally and to acquire genes from non-metazoan sources, lack the canonical eukaryotic C5-methyltransferases but instead encode an amino-methyltransferase of bacterial origin, N4CMT, which is present in all bdelloid families separated by tens of millions of years of evolution. The recombinant N4CMT introduces 4mC into genomic DNA in vivo and in vitro. Using SMRT-seq (PRJNA558051), MeDIP-seq, ChIP-seq, and RNA-seq, we examined genome-wide distribution of non-canonical base modifications over annotated genomic features and observed an excess of 4mC in silenced transposable elements and certain tandem repeats, while 6mA tends to associate with transcribed genes and active chromatin. The presence of the chromodomain in N4CMT explains its affinity for repressive histone marks, H3K9me3 and especially H3K27me3. Our results expand the known repertoire of eukaryotic base modifications, shed light on the process of recruitment of methyl groups as epigenetic marks in DNA, and highlight the role of horizontal gene transfer as an important driver of evolutionary innovation in eukaryotes.
2022-01-07 | GSE140051 | GEO
Project description:Methylation of cytosines at the 5th carbon position of the aromatic ring has long been regarded as the predominant type of DNA base modification in eukaryotes. Often called “the fifth base”, C5-methylcytosine (5mC) plays an important role in genome defense against mobile genetic elements, and is mostly associated with transcriptional silencing, establishment of the closed chromatin configuration, and repressive histone modifications. Recently, another type of DNA modification, N6-methyladenine (6mA), has been added to the repertoire of modified bases in eukaryotic DNA, and was mostly linked to elevated transcription levels. In prokaryotes, 5mC and 6mA typically constitute components of restriction-modification (R-M) systems, along with N4-methylcytosine (4mC), which so far has been confined to bacteria. Here we report the first case of 4mC occurrence in eukaryotic DNA. We find that bdelloid rotifers, small freshwater invertebrates known for their ability to reproduce clonally and to acquire genes from non-metazoan sources, lack the canonical eukaryotic C5-methyltransferases but instead encode an amino-methyltransferase of bacterial origin, N4CMT, which is present in all bdelloid families separated by tens of millions of years of evolution. The recombinant N4CMT introduces 4mC into genomic DNA in vivo and in vitro. Using SMRT-seq (PRJNA558051), MeDIP-seq, ChIP-seq, and RNA-seq, we examined genome-wide distribution of non-canonical base modifications over annotated genomic features and observed an excess of 4mC in silenced transposable elements and certain tandem repeats, while 6mA tends to associate with transcribed genes and active chromatin. The presence of the chromodomain in N4CMT explains its affinity for repressive histone marks, H3K9me3 and especially H3K27me3. Our results expand the known repertoire of eukaryotic base modifications, shed light on the process of recruitment of methyl groups as epigenetic marks in DNA, and highlight the role of horizontal gene transfer as an important driver of evolutionary innovation in eukaryotes.
2022-01-07 | GSE140050 | GEO
Project description:Methylation of cytosines at the 5th carbon position of the aromatic ring has long been regarded as the predominant type of DNA base modification in eukaryotes. Often called “the fifth base”, C5-methylcytosine (5mC) plays an important role in genome defense against mobile genetic elements, and is mostly associated with transcriptional silencing, establishment of the closed chromatin configuration, and repressive histone modifications. Recently, another type of DNA modification, N6-methyladenine (6mA), has been added to the repertoire of modified bases in eukaryotic DNA, and was mostly linked to elevated transcription levels. In prokaryotes, 5mC and 6mA typically constitute components of restriction-modification (R-M) systems, along with N4-methylcytosine (4mC), which so far has been confined to bacteria. Here we report the first case of 4mC occurrence in eukaryotic DNA. We find that bdelloid rotifers, small freshwater invertebrates known for their ability to reproduce clonally and to acquire genes from non-metazoan sources, lack the canonical eukaryotic C5-methyltransferases but instead encode an amino-methyltransferase of bacterial origin, N4CMT, which is present in all bdelloid families separated by tens of millions of years of evolution. The recombinant N4CMT introduces 4mC into genomic DNA in vivo and in vitro. Using SMRT-seq (PRJNA558051), MeDIP-seq, ChIP-seq, and RNA-seq, we examined genome-wide distribution of non-canonical base modifications over annotated genomic features and observed an excess of 4mC in silenced transposable elements and certain tandem repeats, while 6mA tends to associate with transcribed genes and active chromatin. The presence of the chromodomain in N4CMT explains its affinity for repressive histone marks, H3K9me3 and especially H3K27me3. Our results expand the known repertoire of eukaryotic base modifications, shed light on the process of recruitment of methyl groups as epigenetic marks in DNA, and highlight the role of horizontal gene transfer as an important driver of evolutionary innovation in eukaryotes.
2022-01-07 | GSE140049 | GEO