Dynamics of CTCF- and cohesin-mediated chromatin looping revealed by live-cell imaging.
Science
; 376(6592): 496-501, 2022 04 29.
Article
in En
| MEDLINE
| ID: mdl-35420890
ABSTRACT
Animal genomes are folded into loops and topologically associating domains (TADs) by CTCF and loop-extruding cohesins, but the live dynamics of loop formation and stability remain unknown. Here, we directly visualized chromatin looping at the Fbn2 TAD in mouse embryonic stem cells using super-resolution live-cell imaging and quantified looping dynamics by Bayesian inference. Unexpectedly, the Fbn2 loop was both rare and dynamic, with a looped fraction of approximately 3 to 6.5% and a median loop lifetime of approximately 10 to 30 minutes. Our results establish that the Fbn2 TAD is highly dynamic, and about 92% of the time, cohesin-extruded loops exist within the TAD without bridging both CTCF boundaries. This suggests that single CTCF boundaries, rather than the fully CTCF-CTCF looped state, may be the primary regulators of functional interactions.
Full text:
1
Database:
MEDLINE
Main subject:
Chromatin
/
Chromosomal Proteins, Non-Histone
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Year:
2022
Type:
Article