Micron-scale coherence in interphase chromatin dynamics


Zidovska, A. ; Weitz, D. A. ; Mitchison, T. J. Micron-scale coherence in interphase chromatin dynamics. Proceedings of the National Academy of Sciences of the United States of America 2013, 110, 15555-15560. Copy at http://www.tinyurl.com/myrzp5d
2013_pnas_zidovska.pdf2.49 MB


Chromatin structure and dynamics control all aspects of DNA biology yet are poorly understood, especially at large length scales. We developed an approach, displacement correlation spectroscopy based on time-resolved image correlation analysis, to map chromatin dynamics simultaneously across the whole nucleus in cultured human cells. This method revealed that chromatin movement was coherent across large regions (4-5 mu m) for several seconds. Regions of coherent motion extended beyond the boundaries of single-chromosome territories, suggesting elastic coupling of motion over length scales much larger than those of genes. These large-scale, coupled motions were ATP dependent and unidirectional for several seconds, perhaps accounting for ATP-dependent directed movement of single genes. Perturbation of major nuclear ATPases such as DNA polymerase, RNA polymerase II, and topoisomerase II eliminated micron-scale coherence, while causing rapid, local movement to increase; i.e., local motions accelerated but became uncoupled from their neighbors. We observe similar trends in chromatin dynamics upon inducing a direct DNA damage; thus we hypothesize that this may be due to DNA damage responses that physically relax chromatin and block long-distance communication of forces.

Last updated on 08/08/2014