Ralf Jansen
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ralfjansen.bsky.social
Ralf Jansen
@ralfjansen.bsky.social
BIF PhD fellow in the Brennecke lab (@juliusbrennecke.bsky.social) at IMBA (@imbavienna.bsky.social), Vienna

Interested in transcription and RNA export.

http://www.oeaw.ac.at/imba/research/julius-brennecke
Reposted by Ralf Jansen
just in time for the opening of the @hohmannulrich.bsky.social group at @imbmainz.bsky.social
what started as a project on how cells export piRNA precursors, ended up as a tour de force in mRNA export. truly wonderful collaboration with @plaschkalab.bsky.social at the @viennabiocenter.bsky.social
New paper alert! Scientists in Clemens Plaschka’s lab at the IMP and @juliusbrennecke.bsky.social's lab at
@imbavienna.bsky.social solved a decade-old puzzle, uncovering how the information molecule mRNA travels from the cell’s nucleus to its periphery. More: bit.ly/4nHcvys
November 7, 2025 at 6:03 PM
Reposted by Ralf Jansen
New paper alert! Scientists in Julius Brennecke’s lab at IMBA and Clemens Plaschka’s lab at @impvienna.bsky.social solved a decade-old puzzle, uncovering how the information molecule mRNA travels from the cell’s nucleus to its periphery. More: https://imba.science/3Xl2hJ3
November 6, 2025 at 4:00 PM
Reposted by Ralf Jansen
The Wilkinson Lab is open for science! @mskcancercenter.bsky.social

🧬We'll be finding funky new RNA biology, mainly by looking at reverse transcriptases (i.e. the Best Enzymes In The World)🧬

annnd: I'm hiring - come join! Especially postdocs and PhD students - please get in touch (NYC is great)
Wilkinson Lab
We discover and study reverse transcriptases
wilkinsonlab.bio
October 31, 2025 at 7:00 PM
Reposted by Ralf Jansen
What’s it like doing a PhD between two labs? In our latest Behind the Science, Júlia Portell i de Montserrat, shared PhD student in the Plaschka lab at the IMP and the Brennecke lab at @imbavienna.bsky.social, tells us more about her unusual but rewarding PhD journey: bit.ly/3IHXtdp
October 13, 2025 at 3:07 PM
Reposted by Ralf Jansen
When transposons jump, genomes diverge - even in cultured cells.
I am happy to share our new preprint: a chromosome-scale genome assembly for Drosophila OSC cells, one of the key model systems in the piRNA field, especially for nuclear piRNA biology. 🧬🧵 (1/12)
October 14, 2025 at 8:34 PM
Reposted by Ralf Jansen
Thrilled to share that I’ll be joining @imbmainz.bsky.social in February 2026 to start my own group!
We will explore new mechanisms in eukaryotic gene expression, leveraging ‘evolutionary play’ to uncover how regulation, repurposing, and hijacking shape RNA biology.
PhD positions available!
October 12, 2025 at 8:19 PM
Reposted by Ralf Jansen
How are RNAs sorted for export vs. degradation in the nucleus? In collaboration with @heick.bsky.social’s lab we (@clemensplaschka.bsky.social and @juliusbrennecke.bsky.social labs) discovered a direct mechanistic link between the export and decay machineries: www.biorxiv.org/content/10.1... (1/x)
Molecular basis of polyadenylated RNA fate determination in the nucleus
Eukaryotic genomes generate a plethora of polyadenylated (pA+) RNAs[1][1],[2][2], that are packaged into ribonucleoprotein particles (RNPs). To ensure faithful gene expression, functional pA+ RNPs, in...
www.biorxiv.org
September 22, 2025 at 11:23 PM
Reposted by Ralf Jansen
I am excited to announce that I will be moving to IMB Mainz next year! The Winter call for the IPP PhD program is now open; if you are interested in maternal #mRNA regulation and #translation in early vertebrate development, please apply! Deadline: 16 October.

More info: www.imb.de/students-pos...
Laura Lorenzo Orts
IMB Mainz
www.imb.de
September 15, 2025 at 12:13 PM
Reposted by Ralf Jansen
Love RNA biology?

Join us to explore the piRNA pathway with structural and genetic approaches (see 👇👇).

PhD student/postdoc position co-supervised by Clemens Plaschka & myself.

DM or email us if you’d like to know more!

@vbcscitraining.bsky.social @imbavienna.bsky.social @impvienna.bsky.social
PIWI clade Argonautes are essential for transposon silencing. Without them, animals are sterile due to massive transposon activity.

But how does piRNA-guided target interaction translate into silencing?

PhD student Júlia Portell Montserrat has an intriguing answer

www.cell.com/molecular-ce...
September 18, 2025 at 2:34 PM
Reposted by Ralf Jansen
My first first-author paper is out!🎉
Here we propose a model where a silencing complex, PIWI*, assembles on target RNAs to recruit effectors and shut down transposon activity.
Huge thanks to the Brennecke and Plaschka labs, especially Julius and Clemens, and all co-authors!
PIWI clade Argonautes are essential for transposon silencing. Without them, animals are sterile due to massive transposon activity.

But how does piRNA-guided target interaction translate into silencing?

PhD student Júlia Portell Montserrat has an intriguing answer

www.cell.com/molecular-ce...
September 17, 2025 at 1:00 PM
Reposted by Ralf Jansen
PIWI clade Argonautes are essential for transposon silencing. Without them, animals are sterile due to massive transposon activity.

But how does piRNA-guided target interaction translate into silencing?

PhD student Júlia Portell Montserrat has an intriguing answer

www.cell.com/molecular-ce...
September 17, 2025 at 10:39 AM
Reposted by Ralf Jansen
Close inter-lab collaborations with shared PhD students and postdocs are the future!
Julia is the hero of this work, she is currently looking for postdoc labs …
📰 New paper alert!

In a collaborative project with the lab of Clemens Plaschka at the IMP, the lab of Julius Brennecke has revealed how PIWI proteins kickstart transposon silencing in reproductive cells.

The findings are published in Molecular Cell: www.sciencedirect.com/science/arti...
How cells lock down “jumping genes”:
Researchers from IMBA and IMP identify the first protein interactions that trigger PIWI–piRNA–mediated transposon silencing, using AlphaFold predictions, genetics, biochemistry and cell biology.
Read more: www.viennabiocenter.org/about/news/t...
September 9, 2025 at 10:59 AM
Reposted by Ralf Jansen
New paper by our Plaschka lab with Brennecke’s lab at IMBA!

Researchers at the Vienna BioCenter have solved a 20-year-old mystery in genome biology, revealing how PIWI proteins engage partner molecules to silence “jumping genes” that threaten genetic stability.
How cells lock down “jumping genes”:
Researchers from IMBA and IMP identify the first protein interactions that trigger PIWI–piRNA–mediated transposon silencing, using AlphaFold predictions, genetics, biochemistry and cell biology.
Read more: www.viennabiocenter.org/about/news/t...
September 8, 2025 at 9:10 AM
So happy to see the PhD work of Emilio Santillán published—what an amazingly elegant piece of work!!
Working with him and Luisa at the IMP was a great and formative experience.
Our work on the function of miR-51/miR-100 is out! miR-100 is widely conserved across eumetazoans but its function has been mysterious. Emilio Santillán found in worms it regulates signaling and extracellular matrix genes, some of which seem to be conserved targets! www.science.org/doi/10.1126/...
An ancient and essential miRNA family controls cellular interaction pathways in C. elegans
A microRNA that arose at the origin of eumetazoans regulates cell adhesion and signaling in C. elegans through conserved targets.
www.science.org
September 3, 2025 at 7:46 PM
Reposted by Ralf Jansen
1/ How do animals develop immunity against a newly encountered transposable element from scratch? Our study reveals that the mobility of TEs is their Achilles heel, allowing hosts to develop a powerful small RNA-mediated silencing response.
www.biorxiv.org/content/10.1...
August 14, 2025 at 5:09 PM
My colleagues Baptise Rafanel et al. investigated how a newly invading transposon can be silenced. They found that not only antisense insertions in piRNA clusters such as flamenco, but also insertions in the 3‘UTR of genes can drive potent silencing.
Antisense transposon insertions into host genes trigger piRNA mediated immunity https://www.biorxiv.org/content/10.1101/2025.07.28.667215v1
August 2, 2025 at 8:36 PM
Reposted by Ralf Jansen
Pls. share widely

Calling all transposon fans & lovers of genetic innovation

MOBILE GENOME welcomes you in Heidelberg, Nov. 4–7 2025

→ Vibrant & friendly community
→ Cutting-edge talks from mechanisms to physiology
→ Plenty of surprises (TEs never stop innovating)

submit abstract by July 29
⏰ Abstract deadline for 'The mobile genome' is 29 July!

👉 https://s.embl.org/mge25-01-bl

Join us 4–7 Nov 2025 at EMBL Heidelberg (or online) to explore the impact of TEs across biology. 🧬🔍

⭐🧑🏼‍🔬 24 talks + 15 flash talks from posters – don't miss out!

#EMBOMobileGenome
July 16, 2025 at 8:43 AM
Reposted by Ralf Jansen
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/
July 15, 2025 at 8:11 AM
Reposted by Ralf Jansen
📖 Happy to share our recent preprint! www.biorxiv.org/content/10.1... We discovered how SINEs are kept silent: the ChAHP protein complex acts as a molecular brake on POL III transcription retrotransposons. A 🧵:
ChAHP Silences SINE Retrotransposons by Inhibiting TFIIIB Recruitment
Short interspersed nuclear elements (SINEs) are abundant non-autonomous transposable elements derived from RNA polymerase III (POL III)-transcribed short non-coding RNAs. SINEs retain sequence feature...
www.biorxiv.org
July 3, 2025 at 6:18 AM
Reposted by Ralf Jansen
The fascinating work spearheaded by Kirsten Senti on the diversification and adaptation of endogenous retroviruses in the host gonad 'ecosystem'' is officially published.
🚨📢 New paper alert!
A study led by Kirsten Senti and Julius Brennecke offers new insights into how ancient endogenous retroviruses diversified to exploit different cell “niches” in the fruit fly ovary, and how the host’s defenses adapted in return. https://imba.science/Brennecke_EMBOJ
June 17, 2025 at 8:34 PM
Reposted by Ralf Jansen
I freaking 😍 this paper. The ecology of the genome is one thing. The ecology of the Drosophila ovary another.
The fascinating work spearheaded by Kirsten Senti on the diversification and adaptation of endogenous retroviruses in the host gonad 'ecosystem'' is officially published.
🚨📢 New paper alert!
A study led by Kirsten Senti and Julius Brennecke offers new insights into how ancient endogenous retroviruses diversified to exploit different cell “niches” in the fruit fly ovary, and how the host’s defenses adapted in return. https://imba.science/Brennecke_EMBOJ
June 19, 2025 at 3:26 PM
Reposted by Ralf Jansen
🚨📢 New paper alert!
A study led by Kirsten Senti and Julius Brennecke offers new insights into how ancient endogenous retroviruses diversified to exploit different cell “niches” in the fruit fly ovary, and how the host’s defenses adapted in return. https://imba.science/Brennecke_EMBOJ
June 16, 2025 at 9:40 AM
Reposted by Ralf Jansen
REFEREE 1: “I conclude with a simple, direct statement - this is the best paper I have read all year!”
#TransparentPeerReview

Co-evolving infectivity and expression patterns drive the diversification of endogenous retroviruses
@juliusbrennecke.bsky.social et al

www.embopress.org/doi/full/10....
June 6, 2025 at 2:18 PM
Reposted by Ralf Jansen
The @viennabiocenter.bsky.social PostDoc Program call is now open! We have 16 fully-funded positions for scientists with a PhD in biology, chemistry, physics, bioinformatics etc.

Apply here: training.vbc.ac.at/post-docs/vi...

#VBCPostDoc
June 2, 2025 at 11:28 AM