The molecular basis of cell memory in mammals: The epigenetic cycle

Abstract

Cell memory refers to the capacity of cells to maintain their gene expression program once the initiating environmental signal has ceased. This exceptional feature is key during the formation of mammalian organisms, and it is believed to be in part mediated by epigenetic factors that can endorse cells with the landmarks required to maintain transcriptional programs upon cell duplication. Here, we review current literature analyzing the molecular basis of epigenetic memory in mammals, with a focus on the mechanisms by which transcriptionally repressive chromatin modifications such as methylation of DNA and histone H3 are propagated through mitotic cell divisions. The emerging picture suggests that cellular memory is supported by an epigenetic cycle in which reversible activities carried out by epigenetic regulators in coordination with cell cycle transition create a multiphasic system that can accommodate both maintenance of cell identity and cell differentiation in proliferating stem cell populations.

Role of epigenetics and alterations in RNA metabolism in leukodystrophies

“…Epigenetic modulation provides a rapid and adaptive mechanism in response to different environmental influences, creating an individual molecular signature, also called epigenetic memory (Espinosa-Martínez et al, 2024;Ge & Brickner, 2024). These molecular marks induced by environmental triggers may be transmitted to future generations via intergenerational or transgenerational epigenetic inheritance.…”