Chromatin

Chromatin is the complex of DNA, histones, and associated proteins that packages the genome inside the nucleus. Its basic unit, the nucleosome, can be tightly compacted as heterochromatin or loosely arranged as euchromatin, controlling which genes are accessible for transcription. Chromatin organisation safeguards genomic stability and cellular identity. Loss of heterochromatin and disorganised chromatin architecture are recognised hallmarks of ageing and contribute to cellular dysfunction.