Re:Strange DNA structures linked to cancer
by ralfd on Saturday January 22, 2022 @10:04AM
(#30037278)
In sexually reproducing organisms, much of the epigenetic modification within cells is reset during meiosis.
Re:Strange DNA structures linked to cancer
by rflrob on Saturday January 22, 2022 @12:18PM
(#30038620)
While I’m of the opinion that trans-generational epigenetic inheritance is not typically important in human biology, the most convincing argument I’ve heard is that the egg cells that will become a grandchild are present and post-meiotic in the fetus of the mother, so exposures to the grandmother could have effects 2 generations down without requiring some relatively exotic pattern of inheritance.
Re:Strange DNA structures linked to cancer
by pfisherman on Saturday January 22, 2022 @02:30PM
(#30040009)
Methylation is just one part of epigenetics. There are other types of chemical modifications such as histone acylation that play a role. Also physical interactions such as transcription factor binding, chromatin accessibility, etc. Increasingly the spatial organization of the genome into topologically associated domains (TADs) is thought to impact transcription.
https://en.wikipedia.org/wiki/Cancer_epigenetics
"As Vogelstein et al. point out, in a colorectal cancer there are usually about 3 to 6 driver mutations and 33 to 66 hitchhiker or passenger mutations.[2] However, in colon tumors compared to adjacent normal-appearing colonic mucosa, there are about 600 to 800 heavily methylated CpG islands in promoters of genes in the tumors while these CpG islands are not methylated in the adjacent mucosa."