scholarly journals Coupling chromatin structure and dynamics by live super-resolution imaging

2020 ◽  
Vol 6 (27) ◽  
pp. eaaz2196 ◽  
Author(s):  
R. Barth ◽  
K. Bystricky ◽  
H. A. Shaban

Chromatin conformation regulates gene expression and thus, constant remodeling of chromatin structure is essential to guarantee proper cell function. To gain insight into the spatiotemporal organization of the genome, we use high-density photoactivated localization microscopy and deep learning to obtain temporally resolved super-resolution images of chromatin in living cells. In combination with high-resolution dense motion reconstruction, we find elongated ~45- to 90-nm-wide chromatin “blobs.” A computational chromatin model suggests that these blobs are dynamically associating chromatin fragments in close physical and genomic proximity and adopt topologically associated domain–like interactions in the time-average limit. Experimentally, we found that chromatin exhibits a spatiotemporal correlation over ~4 μm in space and tens of seconds in time, while chromatin dynamics are correlated over ~6 μm and last 40 s. Notably, chromatin structure and dynamics are closely related, which may constitute a mechanism to grant access to regions with high local chromatin concentration.

2019 ◽  
Author(s):  
R. Barth ◽  
K. Bystricky ◽  
H. A. Shaban

AbstractChromatin conformation regulates gene expression and thus constant remodeling of chromatin structure is essential to guarantee proper cell function. To gain insight into the spatio-temporal organization of the genome, we employ high-density photo-activated localization microscopy and deep learning to obtain temporally resolved super-resolution images of chromatin in living cells. In combination with high-resolution dense motion reconstruction, we confirm the existence of elongated ~ 45 to 90 nm wide chromatin ‘blobs’. A computational chromatin model suggests that these blobs are dynamically associating chromatin fragments in close physical and genomic proximity and adopt TAD-like interactions in the time-average limit. Experimentally, we found that chromatin exhibits a spatio-temporal correlation over ~ 4 μm in space and tens of seconds in time, while chromatin dynamics are correlated over ~ 6 μm and last 40 s. Notably, chromatin structure and dynamics are closely related, which may constitute a mechanism to grant access to regions with high local chromatin concentration.


2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.


2021 ◽  
Vol 120 (3) ◽  
pp. 9a
Author(s):  
Dushyant Mehra ◽  
Chiranjib Banerjee ◽  
Santosh Adhikari ◽  
Jacob M. Ritz ◽  
Angel Mancebo ◽  
...  

2021 ◽  
Author(s):  
Dushyant Mehra ◽  
Santosh Adhikari ◽  
Chiranjib Banerjee ◽  
Elias M. Puchner

The dynamic rearrangement of chromatin is critical for gene regulation, but mapping both the spatial organization of chromatin and its dynamics remains a challenge. Many structural conformations are too small to be resolved via conventional fluorescence microscopy and the long acquisition time of super-resolution PALM imaging precludes the structural characterization of chromatin below the optical diffraction limit in living cells due to chromatin motion. Here we develop a correlative conventional fluorescence and PALM imaging approach to quantitatively map time-averaged chromatin structure and dynamics below the optical diffraction limit in living cells. By assigning localizations to a locus as it moves, we reliably discriminate between bound and searching dCas9 molecules, whose mobility overlap. Our approach accounts for changes in DNA mobility and relates local chromatin motion to larger scale domain movement. In our experimental system, we show that compacted telomeres have a higher density of bound dCas9 molecules, but the relative motion of those molecules is more restricted than in less compacted telomeres. Correlative conventional and PALM imaging therefore improves the ability to analyze the mobility and time-averaged nanoscopic structural features of locus specific chromatin with single molecule precision and yields unprecedented insights across length and time scales.


BioEssays ◽  
1994 ◽  
Vol 16 (9) ◽  
pp. 657-662 ◽  
Author(s):  
Andrew A. Travers

2013 ◽  
pp. 306-310
Author(s):  
Heather J. Szerlong ◽  
Jeffrey C. Hansen

Genes ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 493 ◽  
Author(s):  
Birk

Since the advent of super-resolution microscopy, countless approaches and studies have been published contributing significantly to our understanding of cellular processes. With the aid of chromatin-specific fluorescence labeling techniques, we are gaining increasing insight into gene regulation and chromatin organization. Combined with super-resolution imaging and data analysis, these labeling techniques enable direct assessment not only of chromatin interactions but also of the function of specific chromatin conformational states.


2014 ◽  
Vol 15 (9) ◽  
pp. 17162-17187 ◽  
Author(s):  
Valeria Visone ◽  
Antonella Vettone ◽  
Mario Serpe ◽  
Anna Valenti ◽  
Giuseppe Perugino ◽  
...  

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