Thelma Escobar

Abstract Gene expression programmes conferring cellular identity are achieved through the organization of chromatin structures that either facilitate or impede transcription. Among the key determinants of chromatin organization are the histone modifications that correlate with a given transcriptional status and chromatin state. Until recently, the details for the segregation of nucleosomes on DNA replication and their implications in re-establishing heritable chromatin domains remained unclear.

Highlights • CRISPR-biotinylation system to track parental nucleosome segregation at single loci • Biotinylation of replication-dependent histone H3 nucleosomes exclusively in G1/S • Parental nucleosomes redeposit locally in repressed chromatin domains • Parental nucleosomes disperse in the case of active chromatin domains Summary Chromatin domains and their associated structures must be faithfully inherited through cellular division to maintain cellular identity.

Highlights • Transcriptional inhibition disrupts CTCF binding to chromatin • RNA-binding regions (RBRs) in CTCF are found within ZF1 and ZF10 • Gene expression and chromatin binding are disrupted by RBR mutants • Chromatin loops are markedly decreased in ZF1Δ and ZF10Δ mutant rescues Summary The function of the CCCTC-binding factor (CTCF) in the organization of the genome has become an important area of investigation, but the mechanisms by which CTCF dynamically contributes to genome...