Epigenetics: What it is about?

Abstract

Epigenetics has captured the attention of scientists in the past differentiated cells can maintain their phenotypes for decades without undergoing division, which points out the limitation of the «heritability» criterion for a particular phenomenon to qualify as epigenetic. «Epigenetic stability» encompasses traits preservation in both dividing and non dividing cells. Likewise, the use of the term «epigenetic regulation» has been misleading as it overlaps with «regulation of gene expression», whereas «epigenetic information» clearly distinguishes epigenetic from genetic phenomena. Consequently, how could epigenetic information be transmitted and perpetuated? The term «epigenetic templating» has been proposed to refer to a general mechanism of perpetuation of epigenetic information that is based on the preferential activity of enzymes that deposit a particular epi

Epigenetic Error and Large-scale Genomic Instability in Cancer

“…From an evolutionary point of view, it is likely that epigenetic markers arose as a means of protecting genetic information [1]. The primary epigenetic marker is DNA methylation and DNA methylation would furnish a way to distinguish between 'self' and 'foreign' genetic material as, for example, for the selective action of the restriction endonuclease system in bacteria [2].…”

Molecular turnover, the H3.3 dilemma and organismal aging (hypothesis)

“…These mechanisms play a role in the maintenance of differentiated phenotypes in cell lineages during embryonic development and in adult ages, although their primary evolutionary role might have been to protect genetic information, for example, via suppression of parasitic genetic elements (Saade & Ogryzko, 2014). …”

“…Epigenetics focuses on the mechanisms of processing of epigenetic informationdefined here as information that is both (i) necessary to determine the state of an organism in addition to its DNA sequence (i.e., genetic information) and (ii) relatively stable compared to the characteristic times of metabolic changes and cellular lifespan (Russo et al, 1996;Bird, 2007). These mechanisms play a role in the maintenance of differentiated phenotypes in cell lineages during embryonic development and in adult ages, although their primary evolutionary role might have been to protect genetic information, for example, via suppression of parasitic genetic elements (Saade & Ogryzko, 2014).…”

Topokaryotyping – a proposal for a novel approach to study nuclear organization

“…Several levels of chromatin compaction are known, and the information about every level of this organization -from the nucleosome positioning to its higher level folding and ultimately to the location of a particular genomic sequence in the nucleus (topological organization of genome) -appears to be important for the understanding of various aspects of a gene function, including transcription, replication, repair and recombination [1].…”