Cohesin-mediated loops control search range
When we disrupted cohesin regulators, search dynamics changed:
🔹 Reducing loops by NIPBL depletion narrowed homology search
🔹 Expanding loops by WAPL depletion made the search broader
Cohesin loops regulate homology search range!
When we disrupted cohesin regulators, search dynamics changed:
🔹 Reducing loops by NIPBL depletion narrowed homology search
🔹 Expanding loops by WAPL depletion made the search broader
Cohesin loops regulate homology search range!
Comments
Homology-directed repair normally uses the sister chromatid as a template, but how does a DSB find its sister locus in 3D space? We developed sister-pore-C, a high-resolution method to map chromatin interactions within & between sister chromatids.
Sister-pore-C allows us to track how DNA architecture changes before and after DSBs. We found that DSBs locally increase loops and interactions between the broken ends and the intact sister chromatid.
What happens if we disrupt sister cohesion? Upon sororin depletion (cohesion stabilizer):
✅ Loops remain intact
❌ Contacts between sister chromatids are lost
🔹Loop-forming cohesin defines search space, limited by TADs
🔹Cohesive cohesin tethers the break to its sister, to favour productive interactions
This ensures efficient & accurate homology search!
For more great science on this topic check the post below 👇
New method for monitoring homology search (RaPID-seq)? Preprint from @charlesyeh.bsky.social in @jcornlab.bsky.social! https://doi.org/10.1101/2025.02.10.63716
(BTW the DOI link is broken)
(Thanks for the DOI heads up, bluesky cut in the preview and it went unnoticed)