Really happy to share that our preprint is now published in @narjournal.bsky.social! 🎉

now published at BMC Biology!
rdcu.be/fdITD

There are Science papers and then there are *I just dropped and shattered my mug of coffee Usual Suspects style* Science papers www.science.org/doi/10.1126/...

✍️ The @sandraduharcourt.bsky.social Lab published a new article
📖 Genome Biology
📃 A H3K27me3 reader complex couples H3K27me3 accumulation to nascent transcription of transposable elements in Paramecium

🔗 link.springer.com/article/10.1...

Merci Raphaël !!

Thanks Max!

Thank you Bassem!

Thank you Peter!

Thanks Ralf!

First first-author paper out! 🎉

We show that the classically repressive mark H3K27me3 can be linked to active transcription through a newly identified reader complex 🤯

Really grateful to everyone involved in this project during my PhD!

Thread below 👇

Germ cells have their own versions of core transcription factors and fertility depends on them.
We're hiring a PhD student to figure out how! 📢
Fly genetics + proteomics + genomics. Fully funded.
Aarhus University 🇩🇰
Deadline May 1 👇

Please share with anyone who might be interested!

Our work on chromatin evolution in brown algae is finally out!

This is also my first "co-first author" paper!! I’m excited to share what we found 👇

Excited to share our new preprint exploring how Paramecium achieves diverse flow functions, i.e. feeding and swimming, simultaneously. This work was spearheaded by our ExM expert, PhD student Daphne Laan @daphnelaan.bsky.social :
www.biorxiv.org/content/10.6...

Excited to announce the upcoming Jacques Monod Conference on the mechanistic and evolutionary basis of programmed DNA elimination (Sept 21–25, 2026):
cjm.sb-roscoff.fr/en/conferenc...
Organized by @laurarossevo.bsky.social and myself.

How does the piRNA pathway solve the self vs. non-self problem? 🧬

Since piRNAs come from single-stranded RNA, how does the cell choose the right ones? For years, "piRNA clusters" were seen as THE privileged source. But are they really special and earmarked for biogenesis? (1/19)

A Naïve RNA Sampling Core Enables Adaptive piRNA Specificity Against Transposable Elements www.biorxiv.org/content/10.64898/2026.02...

Programmed ‘DNA splicing’ removes transposons from genes Nature Reviews Molecular Cell Biology - A study that showed that programmed DNA elimination in somatic genomes of ciliates involves excision of intrusive, transposon-derived sequences from genes.

Happy to begin the year with the publication of a Journal Club article - Programmed ‘DNA splicing’ removes transposons from genes.
rdcu.be/eXBym

Adenine DNA methylation associated with transcriptionally permissive chromatin is widespread across eukaryotes - Nature Genetics Long-read sequencing in 18 unicellular eukaryotes reveals that 6mA is widespread across eukaryotes and is enriched at transcriptionally permissive regions, which are also marked by H3K4me3.

Out today, our take on 6-methyladenine #6mA evolution in Eukaryotes @natgenet.nature.com. We asked a simple question, is really DNA 6mA common across the eukaryotes? The answer is "yes" if you're a unicellular eukaryote 🦠, not so if you're multicellular 🐝🌱🍄. www.nature.com/articles/s41... 1/9

The tiny germline chromosomes of Paramecium aurelia have an exceptionally high recombination rate and are capped by a new class of Helitrons Background. Paramecia belong to the ciliate phylum of unicellular eukaryotes characterized by nuclear dimorphism. A diploid germline micronucleus (MIC) transmits genetic information across sexual gene...

Excited to share our new preprint on BioRxiv!
A collaborative effort spanning many years and several labs to uncover what the germline chromosomes of Paramecium really look like. 🔗 www.biorxiv.org/content/10.1...
1/5

Congrats Andreas!!

Lab’s first paper is out!! We show the first structures of #Asgard #chromatin by #cryo-EM 🧬❄️
Asgard histones form closed and open hypernucleosomes. Closed are conserved across #Archaea, while open resemble eukaryotic H3–H4 octasomes and are Asgard-specific. More here: www.cell.com/molecular-ce...

BMP signaling-dependent dorsal-to-ventral gradient of PAX3/7 transcriptional activity revealed by the P34::tk::LacZ reporter. Left: expression patterns of neural progenitor (NP) and interneuron (IN) TF markers in the developing spinal cord. Right: Immunostaining for β-galactosidase (β-gal; red/grey), GFP (blue/grey) and either OLIG3 (green/grey) or pSMAD1/5/9 (green/grey) on transverse sections of E9.0 (bottom) and E9.5 (top) P34::tk::LacZ; Pax3+/GFP spinal cords at brachial level. Black and white panels show magnified views of the boxed region.

How do pleiotropic TFs generate organized diversity in developing tissues? @spinalorga.bsky.social shows that PAX3 & PAX7 organize #SpinalCord by acting as both repressors & pioneer activators, regulated by #morphogens to ensure precise neural subtype specification @plosbiology.org 🧪 plos.io/4qumsla

Thanks Max!!

@ijmonod.bsky.social @i2bcparissaclay.bsky.social @frm-officiel.bsky.social @EUR_G.E.N.E @upcite.bsky.social

This is part of my PhD work that I recently concluded in the lab of @sandraduharcourt.bsky.social 🎓 🎓
Huge thanks to everyone who contributed to this story (Mélanie, Marc & Valério, who are co-authors with me on this project !) as well as all collaborators for their dedication and insights. 🎉

By revealing how condensin I assists a domesticated transposase in sculpting the somatic genome, this work opens the door to exploring how genome organisation shapes DNA elimination in Paramecium 🤩

👉 To conclude, we show that condensin I physically and functionally interacts with PiggyMac, thus highlighting a strong interaction between the two machineries.

🧬 We demonstrate that this new development-specific complex is essential for DNA elimination and the establishment of H3K9me3 & H3K27me3 patterns during development, fully phenocopying PiggyMac depletion.

🧪Using TurboID proximity labelling, we identified condensin I subunits among the closest interactors of the PiggyMac endonuclease, leading to the identification of a development-specific condensin I complex

Small‐RNA‐guided histone modifications and somatic genome elimination in ciliates In ciliates, an ancestral pathway for transposable element repression by small RNAs and histone methyltransferases has evolved into a highly orchestrated process to eliminate unwanted sequences from ...

During Paramecium development, 30% of the germline genome, including TEs, is precisely eliminated to form a functional somatic genome.
The endonuclease PiggyMac and its partners catalyse this process, but how they are targeted to DNA is unknown. (see doi.org/10.1002/wrna... for more)