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. 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.