Thread by @ChiragNepal

Just read 2012 review @NatureRevGenet pubmed.ncbi.nlm.nih.gov/22641018/
DNA methylation has instructive role in initiating or reinforcing silencing ?? Open question !!
#NotDNAmExpert, my take, DNAm reinforces silencing. Please share your thoughts.

#DNAm of the Hprt gene on the inactive X chromosome occurred after the chromosome had been inactivated. In other words, #DNAm appeared to serve as a ‘lock’ to reinforce a previously silenced state of X-linked genes. @CellCellPress pubmed.ncbi.nlm.nih.gov/3791414/

In cancer cells, genes with CGI promoters that are already silenced by Polycomb are more likely than other genes to become DNAm in cancer: that is, the silent state precedes methylation. #TooManyRefsForThis

This @PNASNews paper showed Gene activation precedes DNA demethylation in response to infection in human dendritic cells
pnas.org/content/116/14…

Why #DNAm is probably not an initial silencing mechanism? pubmed.ncbi.nlm.nih.gov/17687327/ De novo methylation could not occur on nucleosome bearing H3K4me2/3 marks, which are associated with active genes. Active TSSs are depleted of nucleosomes and lack substrate for de novo methylation

CGI genes have larger nucleosome depleted regions, so R these genes less likely to be reg by #DNAm and more likely to be reg by histone-mod. #MayBeTrue But PRC2 bound CGI genes are often most HyperMet in cancer and some r overExp in cancer. @NatureComms nature.com/articles/s4146…

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