Epigenetics

Bridge Epigenetic marks — DNA methylation and histone modifications — can persist across generations without altering DNA sequence, providing a molecular mechanism by which historical trauma (genocide, famine, war) leaves measurable biological signatures in descendants, bridging social history with molecular epigenomics.

Fields: Molecular Biology, Epigenetics, Social Science, Psychology, Public Health

Epigenetic modifications — primarily CpG methylation of DNA and post- translational modifications of histones (H3K4me3, H3K27me3) — regulate gene expression without altering the underlying DNA sequenc...

Bridge Chromatin remodeling defines the epigenetic landscape as a biophysical energy surface where nucleosome positions are attractors and ATP-dependent remodeling complexes act as thermal fluctuation amplifiers that enable transitions between chromatin states — making Waddington's epigenetic landscape a quantitative free-energy landscape in the nucleosome positioning problem.

Fields: Epigenetics, Biophysics, Cell Biology, Systems Biology

Waddington (1957) used the metaphor of a ball rolling down a landscape of valleys (cell fates) to describe development. Chromatin biophysics makes this literal: nucleosome positioning along DNA create...

Bridge Protein post-translational modifications bridge chemistry and biology: the PTM code — phosphorylation, ubiquitination, acetylation, glycosylation, and SUMOylation — acts as a combinatorial language that expands the proteome 100-fold and enables the epigenetic histone code.

Fields: Chemistry, Biology, Biochemistry, Cell Biology, Epigenetics

Post-translational modifications (PTMs) are covalent chemical additions to amino acid side chains that expand proteome diversity and regulatory complexity far beyond what the genome encodes. The major...

Bridge DNA methylation epigenetic clocks are quantitative aging biomarkers that predict chronological and biological age with sub-decade accuracy, bridging epigenetics and geroscience by operationalizing the rate of biological aging.

Fields: Epigenetics, Geroscience, Genomics

Epigenetic clocks (Horvath, Hannum, PhenoAge, GrimAge) use penalized regression on CpG methylation levels across hundreds of genomic loci to construct a quantitative biomarker of biological age that p...

Bridge The biology of chronic stress bridges social science and biology: social determinants of health (employment, neighborhood, social status) are biologically embedded via the HPA axis, cortisol dysregulation, telomere shortening, and epigenetic modification — translating social inequality into measurable molecular and cellular damage.

Fields: Social Science, Sociology, Biology, Endocrinology, Epidemiology, Public Health, Epigenetics

Allostatic load (McEwen & Stellar 1993): chronic activation of stress-response systems (HPA axis, sympathetic nervous system, immune system) causes cumulative physiological wear that manifests as elev...