Gene body methylation safeguards ribosomal DNA transcription by preventing PHF6-mediated enrichment of repressive histone mark H4K20me3

Abstract

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Genome-wide DNA methylation reveals potential epigenetic mechanism of age-dependent viral susceptibility in grass carp

“…Enrichment analysis revealed that gene body hyper-DMGs were involved in genes related to transcription, biosynthesis, and metabolism, all of them are constitutively expressed genes. It was proposed that the function of gene body hypermethylation is most likely homeostatic, which may maintain gene expression in response to developmental and/or environmental stresses [ 38 ]. Therefore, the high gene body methylation levels in TYO fish may imply that the TYO fish was more stable than FMO fish after GCRV infection, which may be one of the reasons for age-dependent viral susceptibility in grass carp.…”

Ribosomal DNA methylation in human and mouse oocytes increases with age

“…Thus, similar to the aging male mammalian germline, the entire rDNA transcription unit in oocytes may be susceptible to aging. In contrast to promoter regions, gene body methylation promotes transcription of rDNA [ 26 ].…”

“…Promoter methylation inhibits assembly of the transcription initiation process and, consequently rDNA transcription and expression [ 25 ]. In contrast, gene body methylation prevents binding of repressive histone marks to maintain transcription [ 26 ]. Advanced parental age is associated with increased methylation of rDNA UCE and core promoter in both oocyte and sperm, which may affect nucleolar biology of the resulting embryos.…”

“…Thus, similar to the aging male mammalian germline, the entire rDNA transcription unit in oocytes may be susceptible to aging. In contrast to promoter regions, gene body methylation promotes transcription of rDNA [26]. In somatic cells and spermatogonial stem cells, methylation changes could be due to errors in the maintenance of DNA methylation patterns and epigenetic drift.…”

“…The human genome is endowed with several hundred (315±104) rDNA transcription units, each containing more than 1,500 CpG sites [ 24 ]. Promoter methylation of the tandemly arrayed transcription units on the acrocentric short arms leads to epigenetic rDNA silencing [ 25 ], whereas gene body methylation may enhance rDNA transcription [ 26 ]. In turn, rDNA transcription affects ribosome biogenesis, overall protein synthesis, and essentially each cellular process.…”