Lauriane Simon

SUMMARY Controlled transcription of genes is critical for cell differentiation and development. Gene expression regulation therefore involves a multilayered control from nucleosome composition in histone variants and their post‐translational modifications to higher‐order folding of chromatin fibers and chromatin interactions in nuclear space. Recent technological advances have allowed gaining insight into these mechanisms, the interplay between local and higher‐order chromatin organization, and the dynamic changes that occur during stress response and developmental transitions. In this review, we will discuss chromatin organization from the nucleosome to its three‐dimensional structure in the nucleus, and consider how these different layers of organization are maintained during the cell cycle or rapidly reprogrammed during development.