How does cohesin guide homology search? New preprint from @AlbertoMarinG1 in the @taekjip lab! New method for monitoring homology search (RaPID-seq)? Check the preprint from the @jcornlab !

Congrats to @FedeTeloni and all co-authors! Many thanks to @IMBA_Vienna & the fantastic facilities @viennabiocenter. This work was supported by @ERC_Research , @MSCActions , @FWF_at, @snsf_ch , @EMBO , #WWTF & #BIF. For more great science on this topic check below 👇11/12.

We propose a dual function of cohesin in homology search:. 🔹Loop-forming cohesin defines search space, limited by TADs.🔹Cohesive cohesin tethers the break to its sister, to favor productive interactions.This ensures efficient & accurate homology search! 10/12

DSBs recruit two cohesin pools to distinct domains. 🔹Loop-forming cohesin accumulates across ~1 Mb, controlling homology sampling range. 🔹Cohesive cohesin accumulates at DSBs, tethering the broken DNA ends to the intact sister chromatid. 9/12

Cohesion directs homology search towards sister chromatid. What happens if we disrupt sister cohesion? Upon sororin depletion (cohesion stabilizer):.✅ Loops remain intact.❌ Contacts between sister chromatids are lost.8/12

DSBs remodel sister chromatids in cis and trans. 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. 7/12

A new tool: sister-pore-C. 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. 6/12

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! 5/12

RAD51 filaments sample local TADs. By mapping RAD51, a key repair protein, we found that homology search occurs within topologically associated domains near the break rather than across the entire genome. How does chromosome organization influence the search range? 4/12

Site-specific induction of homology-directed repair. To study how chromosome architecture influences homology search, we induced DSBs at specific genomic sites in S/G2-synchronized human cells. Most breaks were repaired by homologous recombination. 3/12

The challenge of homology search. DNA double-strand breaks (DSBs) are dangerous, but homologous recombination repairs them accurately using a homologous template. How do broken DNA ends find homology sites in the folded chromatin architecture of the nucleus? 2/12.

New #preprint from our lab at @IMBA_Vienna !.How do DNA breaks locate homology sites in the vast space of the human genome? We show how #cohesin guides homology search for faithful repair!.Read more 👉 Follow along for key insights! 🧵1/12.

The Gerlich lab is once again offering a stipended, 9-week Summer School position for undergraduates in 2025 - a chance to join us in Vienna and research chromatin & transcription. For more information, head to

Just had our annual lab christmas dinner, featuring curry and Schrottwichteln (a not-quite-secret-santa, rules here: . Wishing you a festive end to 2024!

RT @PlantoPhagy: 📢📢📢Please RT‼️ Ma Lab @gmivienna @viennabiocenter are hiring at #PhD #postdoc & @technician levels. They will study insect….

RT @IMPvienna: The IMP took a group photo after it started its operations in 1988, so we thought it's getting time for an update. Now with….

Want to join the Gerlich lab? We are hiring! We are offering a fully funded position in this year's winter call for the @viennabiocenter PhD programme. Apply below ahead of the 15th October deadline #viennawaitsforyou.

A great big congratulations to Sofia, who successfully defended her PhD thesis @IMBA_Vienna yesterday. Here’s one happy graduate complete with traditional lab-made defense hat 🎩 Well done Sofia!. @SofiaKolesni29 @viennabiocenter @TrainingVbc

RT @IMBA_Vienna: 🧬📚 👏🏻 Congrats to our visiting summer school students and host groups: Sanne (@Gerlich_Lab), Bella (@grade_sofia), Maria J….

This week we waved goodbye to the fantastic Sanne Wijma, who joined our lab as part of the annual @viennabiocenter summer school. Sanne presented her work in yesterday’s summer school symposium, and we couldn’t be more proud!.