Labile H3.3+H2A.Z nucleosomes mark 'nucleosome-free regions'

Chromatin marks, including histone modifications and variants, have become important tools for characterizing epigenomes, yet how they might interact with one another to facilitate gene expression and regulation has remained unclear. a new study maps unstable nucleosomes containing both H3.3 and H2A.Z histone variants to human promoters and regulatory elements and suggests that transient occupancy by double-variant nucleosomes is a general feature of eukaryotic gene regulation.