Spring blooms from self-assembly: epigenetic memory governed by nuclear assemblies and condensates

While trimethylated marks on histone H3K27 encode silenced epigenetic memory states, these alone have been proposed to be insufficient to retain functional memory and state switching over many cell cycles. FLOWERING LOCUS C (FLC) in Arabidopsis thaliana is one such locus silenced by H3K27me3, and which governs the critical timing of flowering after winter cold. Such vernalization silencing at FLC requires the cold-promoted protein VIN3 and the Polycomb accessory protein VRN5. Using single-molecule Slimfield tracking in the living root, we reveal nuclear assemblies of each of VIN3 and VRN5 throughout vernalization.