DNA methylation


: the enzymatically controlled addition of a methyl group to a nucleotide base (such as cytosine in eukaryotes) in a molecule of DNA that plays a role in regulating gene expression (as by the inhibition of genetic transcription)
When a methyl group attaches to a specific spot on a gene—a process called DNA methylation—it can change the gene's expression, turning it off or on, dampening it or making it louder.John Cloud
A handful of drugs that affect DNA methylation already exist, and are being used to treat cancers in which faulty gene labeling plays a role.Helen Pilcher
A process called DNA methylation sets down "marks" on bits of DNA and is typically thought to squelch gene expression.Sarah Baldauf
DNA methylation is a mark on genomic DNA made by addition of methyl groups to cytosine bases …Adrian Bird

Word History

First Known Use

1963, in the meaning defined above

Time Traveler
The first known use of DNA methylation was in 1963

Dictionary Entries Near DNA methylation

Cite this Entry

“DNA methylation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/DNA%20methylation. Accessed 28 Mar. 2023.

Medical Definition

DNA methylation

: the enzymatically controlled methylation of a nucleotide base (as cytosine in eukaryotes) in a molecule of DNA that plays a role in suppressing gene expression
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