Chromatin replication and epigenome maintenance

Abstract

It is known that information that is not contained in the DNA sequence - epigenetic information - can be inherited from the parent to the offspring. However, many questions remain unanswered regarding the extent and mechanisms of such inheritance. In this Review, we consider the evidence for transgenerational epigenetic inheritance via the gametes, including cases of environmentally induced epigenetic changes. The molecular basis of this inheritance remains unclear, but recent evidence points towards diffusible factors, in particular RNA, rather than DNA methylation or chromatin. Interestingly, many cases of epigenetic inheritance seem to involve repeat sequences.

The effects of SUUR protein suggest its role in repressive chromatin renewal during replication inDrosophila

“…While the core replication complex, which performs DNA synthesis, is thoroughly studied, little is known about the molecular mechanisms underlying proper inheritance of epigenetic information during replication. 3,4 Yet, inability of the cell to maintain or correctly read the epigenetic information may result in cancer. 5,6 Maintenance of epigenetic information throughout development requires reestablishment of histone modification marks on chromosomes after each replication cycle.…”

“…As a rule, histone modifications are first diluted after the replication and are subsequently restored more or less rapidly, prior to the next cell cycle (for review see 3 ). Yet, a slightly different scenario was observed for H3K27me3 histone mark in Drosophila cells.…”

“…copies. 3,7 New histones need to be modified according to the local epigenetic state when incorporated into the chromosome. In mammals, some modifications are cast immediately after the replication fork by chromatin factors including chromatin remodelers and histone chaperones; other modifications are introduced later during chromatin maturation, when the replication fork has already passed.…”

Epigenetic setting and reprogramming for neural cell fate determination and differentiation

“…Epigenetic status can change dramatically at the point of DNA synthesis during the cell-cycle progression [71,72]. For example, methylated CpGs are passed on to one of the two daughter DNAs, allowing a difference between the original DNA and daughter DNA in terms of DNA methylation status.…”

Gene Silencing and Polycomb Group Proteins: An Overview of their Structure, Mechanisms and Phylogenetics

“…These modifications, in turn, define the configuration of chromatin and its accessibility to transcriptional machinery (for a review, see Golbabapour et al, 2011). Methylation of H3K9 is important in constitutive heterochromatin, while that of H3K27 is a key repressive factor for the regulation of developmental genes (for a review, see Alabert and Groth, 2012).…”