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Federico Teloni @fedeteloni.bsky.social · Sep 3

Thrilled to share this collaborative work, including our @gerlichlab.bsky.social, uncovering a fundamental charge-based principle of centromere positioning!
Check it out 👇

Gerlich Lab @gerlichlab.bsky.social · Sep 3

1/ New preprint alert!
In collaboration between the Rosen, Redding, Collepardo-Guevara & Gerlich labs, we uncover a surprising principle of chromosome organisation: electrostatic repulsion positions centromeres at the chromosome surface during mitosis.
🔗 doi.org/10.1101/2025...

An electrostatic repulsion model of centromere organisation

During cell division, chromosomes reorganise into compact bodies in which centromeres localise precisely at the chromatin surface to enable kinetochore-microtubule interactions essential for genome se...

doi.org

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Reposted by Federico Teloni

Anton Goloborodko @golobor.bsky.social · Jul 15

We found a new asymmetry in the large-scale chromosome structure: sister chromatids are systematically shifted by hundreds of kb in the 5′→3′ direction of their inherited strands! The work was led by Flavia Corsi, in close collaboration with the Daniel Gerlich lab.
www.biorxiv.org/content/10.1...
1/

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Reposted by Federico Teloni

Andreas Panagopoulos @apanagopoulos.bsky.social · May 21

Delighted to share that the results of my main postdoc project are now published in @nature.com

🔗 doi.org/10.1038/s415...

Multigenerational cell tracking of DNA replication and heritable DNA damage - Nature

A multigenerational single-cell tracking approach provides a framework to dissect phenotypic plasticity at the single-cell level, offering insights into cellular processes that may resemble early even...

doi.org

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Federico Teloni @fedeteloni.bsky.social · May 21

Congratulations for the amazing work!

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Federico Teloni @fedeteloni.bsky.social · Apr 25

Today marks the 80th anniversary of Italy’s Liberation Day, commemorating the end of the Nazi-fascist regime.
The freedom we inherited must be protected every day, because fascism doesn’t belong in the past, unless we keep it there.

La libertà va difesa ogni giorno.
#25aprile #liberazione

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Federico Teloni @fedeteloni.bsky.social · Feb 12

Fixed link www.biorxiv.org/content/10.1...

Proximity determines donor candidacy during DNA double-stranded break homology directed repair

DNA double-stranded breaks (DSBs) are especially toxic events that can be reversed by homology-directed repair (HDR), wherein information is copied from an intact template molecule. RAD51 mediates ini...

www.biorxiv.org

Federico Teloni @fedeteloni.bsky.social · Feb 12

Thanks Jeroen!

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Federico Teloni @fedeteloni.bsky.social · Feb 12

Yes, after replication sisters are linked by cohesion, making them the preferred template for HR: this restricts the area of search, but additionally we observe that loop-forming and cohesive cohesin work together to define a proper search domain and establish productive contacts

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Federico Teloni @fedeteloni.bsky.social · Feb 12

doi.org/10.1101/2025...

Cohesin guides homology search during DNA repair via loops and sister chromatid linkages

Accurate repair of DNA double-strand breaks (DSBs) is essential for genome stability, and defective repair underlies diseases such as cancer. Homologous recombination uses an intact homologous sequenc...

doi.org

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Federico Teloni @fedeteloni.bsky.social · Feb 12

The study is specific for homologous search of HR during S/G2 phase, we didn't take a look at meiosis yet, but definitely something interesting to pursue.

(Thanks for the DOI heads up, bluesky cut in the preview and it went unnoticed)

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Federico Teloni @fedeteloni.bsky.social · Feb 12

Now with the proper working link, sorry for the trouble! doi.org/10.1101/2025...

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Federico Teloni @fedeteloni.bsky.social · Feb 12

How does cohesin guide homology search? Preprint from @albertomarin.bsky.social in the Ha lab! https://doi.org/10.1101/2025.02.10.637451

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

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Federico Teloni @fedeteloni.bsky.social · Feb 12

Huge thanks to my co-authors, @imbavienna.bsky.social and the fantastic facilities at @viennabiocenter.bsky.social. This work was supported by @erc.europa.eu, #MSCA, @fwf-at.bsky.social, @snsf-ch.bsky.social, @embo.org, @wwtf.at & #BIF.
For more great science on this topic check the post below 👇

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Federico Teloni @fedeteloni.bsky.social · Feb 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 favour productive interactions

This ensures efficient & accurate homology search!

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Federico Teloni @fedeteloni.bsky.social · Feb 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

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Federico Teloni @fedeteloni.bsky.social · Feb 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.

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Federico Teloni @fedeteloni.bsky.social · Feb 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.

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Federico Teloni @fedeteloni.bsky.social · Feb 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!

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Federico Teloni @fedeteloni.bsky.social · Feb 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 breakrather than across the entire genome.
How does chromosome organization influence the search range?

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Federico Teloni @fedeteloni.bsky.social · Feb 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.

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Federico Teloni @fedeteloni.bsky.social · Feb 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?

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Federico Teloni @fedeteloni.bsky.social · Feb 12

New preprint from the @gerlichlab.bsky.social @imbavienna.bsky.social!

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 👉 https://doi.org/10.1101/2025.02.10

Follow along for key insights! 🧵

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Federico Teloni @fedeteloni.bsky.social · Jan 23

You never know what people might find valuable these days, I guess willhaben is the way!

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Federico Teloni @fedeteloni.bsky.social · Jan 23

Looks like a "portable" speaker system for old iPods! Almost a relic 😂

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Reposted by Federico Teloni

Vienna BioCenter Scientific Training @vbcscitraining.bsky.social · Nov 29

The Vienna Biocenter Summer School 2025 call is now open for talented undergrads, it's a great prog. for students who are interested in the life sciences.
training.vbc.ac.at/summer-school/ @impvienna.bsky.social @imbavienna.bsky.social @gmivienna.bsky.social @maxperutzlabs.bsky.social

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