Colloquium

Chromatin organisation is inherently dynamic and tightly coupled to gene regulation. Within the nucleus, condensed heterochromatin is typically transcriptionally repressed, whereas more open euchromatin is associated with activity. ATP-dependent chromatin remodelers reshape this landscape by promoting loop formation and by sliding, evicting, and rebinding nucleosomes. Although these processes clearly influence genome architecture, their respective contributions to spatial folding and temporal dynamics remain unresolved. In this talk I will present an active-polymer modelling framework for chromatin that explicitly incorporates remodeler-driven activity. We use it to disentangle how loop-mediated compaction and nucleosome-level remodelling set condensation levels and dynamical regimes. The resulting static and dynamic structures are consistent with key experimental observations, offering mechanistic insight into how active processes coordinate chromatin folding across scales.