PT  - JOURNAL ARTICLE
AU  - Haitham A. Shaban
AU  - Roman Barth
AU  - Kerstin Bystricky
TI  - Nanoscale mapping of chromatin dynamics in living cells
AID  - 10.1101/405969
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 405969
4099  - http://biorxiv.org/content/early/2019/11/25/405969.short
4100  - http://biorxiv.org/content/early/2019/11/25/405969.full
AB  - Principles of genome folding and their relationship to function depend on understanding conformational changes of the chromatin fiber in real-time. However, bulk chromatin motion has not been analysed at high resolution. We developed Hi-D, a method to quantitatively map dynamics of chromatin and abundant nuclear proteins for every pixel simultaneously over the entire nucleus from fluorescence image series. Hi-D combines reconstruction of chromatin motion using computer vision and classification of local diffusion processes by Bayesian inference. We discovered that DNA dynamics in the nuclear interior are spatially partitioned into 0.3 – 3 µm domains in a mosaic-like manner which is uncoupled from chromatin compaction. This pattern was remodeled in response to transcriptional activity accompanied by global reduction of DNA dynamics. In contrast, we found that RNA polymerase II dynamics are, compared to actively transcribing cells, reduced in quiescent cells and when elongation was inhibited. Our results strengthen the hypothesis that chromatin dynamics are dictated by interchromatin contacts, rather than chromatin density. Hi-D can be applied to any dense and bulk structures opening new perspectives towards understanding motion of nuclear molecules in the context of nuclear architecture.