Dna Methylation
Dna Methylation - Related Videos
08:47
DNA Methylation Analysis
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2023
Methylation at CpG dinucleotides is a chemical modification of DNA hypothesized to play important roles in regulating gene expression. In particular, the methylation of clusters of methylation sites, called “CpG islands”, near promoters and other gene regulatory elements may contribute to the stable silencing of genes, for example, during epigenetic processes such as genomic imprinting and X-chromosome inactivation. At the same time, aberrant CpG methylation has been shown to be associated with...
21:24
Methylated DNA Immunoprecipitation
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Cited by 43 •
2009
This video demonstrates the protocol for methylated DNA immunoprecipitation (MeDIP). MeDIP is a two day procedure that selectively extracts methylated DNA fragments from a genomic DNA sample using antibodies with specificity for 5 -methylcytosine (anti-5 mC).
12:34
DNA Methylation: Bisulphite Modification and Analysis
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Cited by 75 •
2011
The gold standard for DNA methylation analysis is genomic sequencing of bisulphite converted DNA. This method takes advantage of the increased sensitivity of cytosine compared with 5-methylcytosine (5-MeC) to bisulphite deamination under acidic conditions. Unmethylated cytosines can be distinguished from methylated cytosines after PCR amplification of the target genomic DNA.
08:38
Targeted DNA Methylation Analysis by Next-generation Sequencing
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Cited by 83 •
2015
Bisulfite amplicon sequencing (BSAS) is a method for quantifying cytosine methylation in targeted genomic regions of interest. This method uses bisulfite conversion paired with PCR amplification of target regions prior to next-generation sequencing to produce absolute quantitation of DNA methylation at a base-specific level.
08:40
Methyl-binding DNA capture Sequencing for Patient Tissues
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Cited by 1 •
2016
Here we present a protocol to investigate genome wide DNA methylation in large scale clinical patient screening studies using the Methyl-Binding DNA Capture sequencing (MBDCap-seq or MBD-seq) technology and the subsequent bioinformatics analysis pipeline.
FAQs
DNA methyltransferases target cytosine bases at CpG sites and use S-adenosylmethionine as the methyl-group donor. This enzyme-directed placement creates localized regulatory patterns rather than altering the nucleotide sequence itself. The resulting distribution of methylated sites can therefore help distinguish active and less active genomic regions while preserving the underlying genetic information.
Methylation can reduce transcription directly by interfering with transcription-factor binding at regulatory DNA. It can also act indirectly by recruiting proteins that compact chromatin, making the region less accessible to the transcriptional machinery. These two effects connect a chemical modification at DNA to changes in gene activity and help establish tissue-specific expression patterns.
A sequence change modifies the nucleotide information itself, whereas DNA methylation changes how that information is regulated without changing the nucleotide sequence. This distinction allows cells with the same underlying DNA to maintain different gene-activity patterns. Such regulation is important for cellular identity and for developmental processes that require specialized cell states.
Researchers examine DNA methylation profiles and compare them with gene activity, tissue identity, developmental state, or disease-associated changes. They may also consider the activity of DNA methyltransferases because these enzymes establish the modification at cytosine bases in CpG sites. This approach helps connect molecular patterns with biological outcomes without treating methylation as a change in DNA sequence.
During embryonic development, methylation contributes to the establishment of stable gene-activity patterns that support different cellular identities. It also participates in genomic imprinting and X-chromosome inactivation, examples in which selective regulation helps cells maintain distinct functional states. Studying these patterns clarifies how development can produce specialized tissues while retaining the same nucleotide sequence.
Abnormal methylation profiles are investigated in cancer, aging, environmental responses, and disease mechanisms because they may reveal altered regulation of gene activity. Researchers also study these profiles for diagnostic purposes and as possible targets in therapeutic research. Their value lies in linking measurable epigenetic patterns with biological states that may differ from normal cellular regulation.