Ioannis Tsirkas

Events for February 2026 06-07 July 2026 | Munich, GermanyDNA Replication and Its Impact on Genome and Chromatin MaintenanceWe are RepliFate, a European Training Doctoral Network dedicated to understanding how DNA replication...

We go live!!!

Join us Munich July5-7th to hear exciting research on #Replication by leaders in the field

AND !! registration is FREE 🥳 (but mandatory) - we hope to see many in Munich 🍺 @helmholtzmunich.bsky.social

@replifate.bsky.social @epicrossborders.bsky.social

replifate.eu/event/meetin...

PAF15–PCNA exhaustion governs the strand-specific control of DNA replication Nature - PCNA–PAF15 has a key role in determining replisome dynamics during genome replication and protecting against genome instability.

Dear Colleagues,

Delighted to share that our first lab paper is now published in Nature.!!! 😊😊😊

We identify a previously concealed “safety limit” in DNA replication program: cells intrinsically rate-limit PCNA via PAF15, shaping strand-specific and global replication dynamics.

👉 rdcu.be/e1bBt

Real-Time Segmentation and Classification of Birdsong Syllables for Learning Experiments https://www.biorxiv.org/content/10.64898/2025.12.19.695629v1

Get Mech Arena Download the game and send me a Friend invite!

Mech Arena link.plrm.zone/sdlgo/ki0l4

It was great to be part of this collaboration, I always admired Prof Maya Schuldiner's and Dr Ofir Klein's work.

lnkd.in/dfabHSkx

For the original papers developing the fluorescent scFvs technology in yeast:

lnkd.in/d_KZ8WMK

lnkd.in/dxt9MD6d

DNA replication initiation timing is important for maintaining genome integrity | Journal of Bacteriology The regulation of DNA replication is fundamental to cell growth and cell cycle control. In eukaryotes, under-initiation or over-initiation leads to genome instability. In bacteria, it is unclear how c...

DNA replication initiation timing is important for maintaining genome integrity | Journal of Bacteriology journals.asm.org/doi/10.1128/...

Such a nice review for one of our latest research works!

We look forward to the community's feedback!

We’re officially in Donald Trump’s mad king era All the books that are fit to cook.

The BLS did exactly what it's supposed to do: provide accurate, nonpartisan data. When the numbers showed Trump's "economic boom" was actually a bust (33k jobs vs claimed 291k), he fired the messenger. After all, when it rains too much, true leaders fire the meteorologists.

I don't like the person I become when designing primers

Retrospective and multifactorial single-cell profiling reveals sequential chromatin reorganization during X inactivation - Nature Cell Biology Kefalopoulou, Rullens et al. develop Dam&ChIC to assay chromatin state at two different time points in the same cell. The method was used to study the reorganization of LADs during cell division a...

I am very excited to share our latest work where we describe a new method to profile genome-wide chromatin transitions over time in single cells. Great collaborative effort with the van Oudenaarden group @hubrechtinstitute.bsky.social @oncodeinstitute.bsky.social www.nature.com/articles/s41....

RIF1 orchestrates a multi-step restoration of post-replicative H3K9me3 https://www.biorxiv.org/content/10.1101/2025.07.14.664777v1

🎤 Apply to speak @our TALENT FORUM by July 31!
Showcase YOUR research in Epigenetics & NucleicAcids @www.helmholtz-munich.de & connect with leading scientists

🧳Travel+accommodation covered if selected!
📝 Info+how to apply: lnkd.in/drkRvz7N

#postdoc #career #groupleader #HelmholtzMunich #research

Great week for #manga readers!

#WildStrawberry ch45
#Yattara ch18
#DramaQueen ch23
#Centuria ch56
#Dandadan ch198
#Chainsawman ch206
#Bugego ch10
#MärchenCrown ch11
#TheGodofTime ch5
#AsurasVerdict ch14

Especially the last one was so good! Here are a few artworks.

A Multimodal Adaptive Optical Microscope For In Vivo Imaging from Molecules to Organisms https://www.biorxiv.org/content/10.1101/2025.06.02.657494v1

#spoileralert

#WildStrawberrt #Manga with itdld best double spread. Too sad this is getting axed ;(

RNA transcripts regulate G-quadruplex landscapes through G-loop formation G-quadruplexes (G4s) are prevalent DNA structures that regulate transcription but also threaten genome stability. How G4 dynamics are controlled remains poorly understood. Here, we report that RNA tra...

Excited our paper is out! G-quadruplex (G4) unwinding via an intricate G-loop assembly and disassembly mechanism maintains genome integrity. Pioneered by Koichi Sato with great collaborators Jing Lyu and @simonelsasser.bsky.social Check it out: www.science.org/doi/10.1126/science.adr0493 🧵(1/4)

#spoileralert

#dandadan #manga nailed it this time, one of its coolest #artworks! Remember, this is a weekly #manga!

The material properties of a bacterial-derived biomolecular condensate tune biological function in natural and synthetic systems - Nature Communications “Intracellular phase separation is emerging as a universal principle for organizing biochemical reactions in time and space. Here the authors show that PopZ condensate dynamics support cell division a...

www.nature.com/articles/s41...

POPtag is officially my new favourite named tag! BTW, nice work!

This was a gift from a colleague, and it looks breathtaking. Done within one day (1000 pieces, around 12-15 hours)

A rather remarkable retraction for a paper where apparently no authors contributed! I guess these #papermill authors were a bit too honest... #fraud
@elsevierconnect.bsky.social

doi.org/10.1016/j.ij...

CTC1-STN1-TEN1 controls DNA break repair pathway choice via DNA end resection blockade Antagonistic activities of the 53BP1 axis and the tumor suppressor BRCA1-BARD1 determine whether DNA double-strand breaks (DSBs) are repaired by end joining or homologous recombination. We show that t...

CST complex blocks end resection by BLM-DNA2 or EXO1, therefore promoting non-homologous endjoining and inhibiting repair templated DNA repair.
www.science.org/doi/10.1126/...

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...

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

🔗 doi.org/10.1038/s415...

Pint of Science Munich Explore Pint of Science Deutschland events in Munich

Grab a pint & dive into science! 🍻

Pint of Science is back in Munich:
🗓️ May 19–21, 2025
🕢 19:30–22:00

#HelmholtzMunich researchers share big ideas – from AI to antibodies.

🎟️ Info & tickets: t1p.de/lvpuv

#pint25 #pint25de

Spoiler alert!

#Dandadan #manga #194 does not disappoint this Monday too! Back2back peak chapters!

Excited to share our latest from my postdoc at @mskcancercenter.bsky.social in the Sfeir Lab, in collaboration with the Simon Powell Lab! We uncovered a novel genome repair mechanism in human cells: RNA-templated DNA double-strand break repair (RT-DSBR). (1/5)

Heater, laying in bed, patiently waiting for breakfast.

I used to have nightmares about getting a pet and forgetting to feed it.

I have not had a single one of those dreams since getting Heater because there is not a chance in Hell she will let me forget breakfast.

homer simpson is laying in bed under a blue blanket . Alt: homer simpson is laying in bed under a blue blanket waking up from a nightmare

I just woke up from a nightmare where I was giving a guest lecture to an undergrad cell biology class and none of them knew the central dogma or what DNA or RNA were. I spent an hour teaching that instead. They didn’t understand why they needed to know about DNA for cell biology. 🫠😫😱

What governs where DNA replication begins in human cells? Here, we show that origins of replication in human DNA are epigenetically specified and that crucially, this epigenetic mark is required for both DNA replication and cell proliferation! @narjournal.bsky.social academic.oup.com/nar/article/...

Fluorescence recovery in the Super-Resolution regime reveals subcompartments of 53BP1 foci https://www.biorxiv.org/content/10.1101/2025.05.07.652606v1