ABSTRACT
How the 2-m-long genomic DNA is packaged into chromatin in the 10-µm eukaryotic nucleus is a fundamental question in cell biology. DNA accessibility depends on chromatin structure and dynamics, which basically control all DNA-related processes, such as transcription, DNA replication and repair. The hierarchical model of chromatin organization has been controversial in recent years because live-cell evidence for the existence of chromatin fibers, particularly those 30 nm in diameter, has remained elusive. Herein, we report a DNA-binding, fluorogenic and self-blinking small-molecule probe for the first live-cell 3D superresolution imaging of chromatin fibers with structural plasticity and fast dynamics. Selective inhibition of histone deacetylases led to decompaction of chromatin fibers due to hyperacetylation of histones. Our live-cell imaging results suggest a model of DNA packaging in interphase with the hierarchical organization of nucleosomal arrays and chromatin fibers.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Title slighly modified. Abstract and introduction revised. Fig. 5 revised.
