[Plutocracy]

Hi all, I'm wondering why there are more scientific papers published on methylation than on acetylation. On PubMed, there are 50k results when I type in "DNA methylation", but only 12k results when I type in "histone acetylation". Is there any clear reason why? Methylation being easier to assay, having more clinical importance, or being discovered earlier? Please let me know.

[Furanone]

I cannot speak for DNA derivitization, but my knowledge of polysaccharide analysis where you first methylate the free hydroxyl groups then acid hydrolyze the glycosidic linkages and then acetylate the newly liberated hydroxyl groups before running the derivitized monosaccharides on GC-MS to determine the branching structure, the methylation step is much easier and as far as I know there is less that can go wrong with that step.

[Babcock_Hall]

@OP,

Do you have some idea of when DNA methylation was discovered and when histone acetylation was discovered?

[Plutocracy]

The earliest papers I found were from 1968 for histone acet. and from 1969 for DNA met. Also, there were 1000 papers between '60's-80's for methylation, compared to only 250 papers for acetylation. I'm guessing the difference may be due to the access of methods (Gel electrophoresis for methylation over RNA extraction for acetylation), but I'm not 100% sure.

[Babcock_Hall]

I am under the impression that methylated cytosine residues have been known at least since Chargaff was working on his analytical experiments, and its discovery was even before this.

[Yggdrasil]

It's also worth noting that DNA methylation exits in all domains of life (bacteria, archaea, and eukaryotes), while histones are present only in eukaryotes.

[sjb]

Another thought may be that acetylation is a specific term for ROH -> ROCOMe, rather than ROCOR', though obviously methylation is also specific in this way..?

[Plutocracy]

@ B Hall

I understand that methylation was known at the time of Chargaff (but he didn't work on them, no?), but I believe their regulatory functions were not known until the late 60's, hence my late dates.

@ Ygg

Yes, thank you! That definitely helps explain the discrepancy.

@ sjb

If I'm not mistaken, acetylation is broadly the creation of a new acetyl group to a molecule. Histone acetylation refers to the specific transfer of an acetyl group to a lysine residue of a histone protein.