Methods for mapping three-dimensional genome architecture

Methods ◽  
2020 ◽  
Vol 170 ◽  
pp. 1-3
Author(s):  
Surabhi Chowdhary ◽  
Amoldeep S. Kainth ◽  
David S. Gross
2018 ◽  
Vol 95 (2) ◽  
pp. 189-198
Author(s):  
J.-F. Ouimette ◽  
C. Rougeulle ◽  
R.A. Veitia

2021 ◽  
Author(s):  
Ruoyu Wang ◽  
Joo-Hyung Lee ◽  
Feng Xiong ◽  
Jieun Kim ◽  
Lana Al Hasani ◽  
...  

SARS-CoV-2 has made >190-million infections worldwide, thus it is pivotal to understand the viral impacts on host cells. Many viruses can significantly alter host chromatin, but such roles of SARS-CoV-2 are largely unknown. Here, we characterized the three-dimensional (3D) genome architecture and epigenome landscapes in human cells after SARS-CoV-2 infection, revealing remarkable restructuring of host chromatin architecture. High-resolution Hi-C 3.0 uncovered widespread A compartmental weakening and A-B mixing, together with a global reduction of intra-TAD chromatin contacts. The cohesin complex, a central organizer of the 3D genome, was significantly depleted from intra-TAD regions, supporting that SARS-CoV-2 disrupts cohesin loop extrusion. Calibrated ChIP-Seq verified chromatin restructuring by SARS-CoV-2 that is particularly manifested by a pervasive reduction of euchromatin modifications. Built on the rewired 3D genome/epigenome maps, a modified activity-by-contact model highlights the transcriptional weakening of antiviral interferon response genes or virus sensors (e.g., DDX58) incurred by SARS-CoV-2. In contrast, pro-inflammatory genes (e.g. IL-6) high in severe infections were uniquely regulated by augmented H3K4me3 at their promoters. These findings illustrate how SARS-CoV-2 rewires host chromatin architecture to confer immunological gene deregulation, laying a foundation to characterize the long-term epigenomic impacts of this virus.


Science ◽  
2021 ◽  
Vol 372 (6540) ◽  
pp. 371-378
Author(s):  
Kyle N. Klein ◽  
Peiyao A. Zhao ◽  
Xiaowen Lyu ◽  
Takayo Sasaki ◽  
Daniel A. Bartlett ◽  
...  

The temporal order of DNA replication [replication timing (RT)] is correlated with chromatin modifications and three-dimensional genome architecture; however, causal links have not been established, largely because of an inability to manipulate the global RT program. We show that loss of RIF1 causes near-complete elimination of the RT program by increasing heterogeneity between individual cells. RT changes are coupled with widespread alterations in chromatin modifications and genome compartmentalization. Conditional depletion of RIF1 causes replication-dependent disruption of histone modifications and alterations in genome architecture. These effects were magnified with successive cycles of altered RT. These results support models in which the timing of chromatin replication and thus assembly plays a key role in maintaining the global epigenetic state.


Science ◽  
2013 ◽  
Vol 341 (6147) ◽  
pp. 1237973 ◽  
Author(s):  
Jesse M. Engreitz ◽  
Amy Pandya-Jones ◽  
Patrick McDonel ◽  
Alexander Shishkin ◽  
Klara Sirokman ◽  
...  

Many large noncoding RNAs (lncRNAs) regulate chromatin, but the mechanisms by which they localize to genomic targets remain unexplored. We investigated the localization mechanisms of the Xist lncRNA during X-chromosome inactivation (XCI), a paradigm of lncRNA-mediated chromatin regulation. During the maintenance of XCI, Xist binds broadly across the X chromosome. During initiation of XCI, Xist initially transfers to distal regions across the X chromosome that are not defined by specific sequences. Instead, Xist identifies these regions by exploiting the three-dimensional conformation of the X chromosome. Xist requires its silencing domain to spread across actively transcribed regions and thereby access the entire chromosome. These findings suggest a model in which Xist coats the X chromosome by searching in three dimensions, modifying chromosome structure, and spreading to newly accessible locations.


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