Interindividual epigenetic variability: Sound or noise?

Abstract

Interindividual variability is an inherent characteristic of biological systems. Whereas the underlying molecular sources of interindividual variability remain poorly understood, recent work by Ecker et al. (Ecker S, Chen L, Pancaldi V, Bagger FO, et al. 2017. Genome Biol 18: 18.) sheds light on the characterization of this phenomenon in a complex biological scenario. By combining data from the BLUEPRINT Epigenome Project with a novel analytical approach, these authors were able to measure the degree of transcriptional and epigenetic variability across a wide panel of samples and types of immune cell. Interestingly, neutrophils displayed increased variability compared to monocytes and T cells, which may be related to the crucial role of the former as an initial mediator of immune responses. Here we review recent literature in this area, and discuss some important issues raised by these innovative analyses. Furthermore, we summarize other potential sources of epigenetic variability, such as epigenetic drift and the epigenetic clock, as well as the current ongoing direction of the field. Differential molecular variability of immune cell typesA recent report by Ecker and co-workers has unraveled, in a genome-wide manner, the extent of transcriptional and epigenetic variability in three major immune cell types [11]. Taking advantage of the publicly available BLUEPRINT Human Variation Panel, the authors analyzed RNA-seq and array-based DNA methylation data from 125 donors using transcriptomic and epigenomic datasets matched across

Transcriptome Profiling Analyses in Psoriasis: A Dynamic Contribution of Keratinocytes to the Pathogenesis

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Epigenetic and Transcriptional Variability Shape Phenotypic Plasticity

“…Besides sex, age is the most important non‐genetic source of inter‐individual variability (recently reviewed by Tejedor and Fraga). It has been shown that epigenetic marks change over life to such an extent that an individual's age can be predicted from its DNA methylation profile .…”

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