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Anouk Willemsen

@willemsenanouk.bsky.social
2.1K followers 223 following 73 posts

Scientist working on genome evolution, viruses, computational molecular evolution, and experimental evolution. 👩🏼‍🔬 🇪🇺🇳🇱🇪🇸🇫🇷🇦🇹 veelab.univie.ac.at

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Anouk Willemsen @willemsenanouk.bsky.social · 24/09/2026
Why did some #viruses #evolve to be giants while others did not? ".. #giantViruses are typical viruses that evolved from smaller ones via accretion of genes recruited from the hosts." doi.org/10.1073/pnas... @mkrupovic.bsky.social & E. Koonin
doi.org
Why did some viruses evolve to be giants while others did not? | PNAS
Viruses are ubiquitous mobile genetic elements that are obligate symbionts of cellular life forms and replicate exclusively within host cells. The ...
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Alejandro Manzano Marín @amanzanom.bsky.social · 18/09/2026
Please help spread the word! I'm searching for a #PhD student to join my group to work on #Symbiont - #pathogen interactions in #Hemiptera. Fully-funded, 4 years *Full details 👇🏼 besymblab.univie.ac.at/wp-content/u... 🧵 on the project 👇🏼 bsky.app/profile/aman... #ScienceJobs #SymbioSky #MicroSky
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Anouk Willemsen @willemsenanouk.bsky.social · 23/08/2026
Decoding the deep: The #ecology, biogeography, and #evolution of #deepSea #viruses doi.org/10.1146/annu... #VirEvol #PhageSky
doi.org
Decoding the Deep: The Ecology, Biogeography, and Evolution of Deep-Sea Viruses
Viruses dominate the deep-ocean biosphere (>200-m depth) yet remain profoundly understudied. As the most abundant biological entities on Earth, they govern the geochemistry, evolution, and ecology ...
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Anouk Willemsen @willemsenanouk.bsky.social · 11/08/2026
#giantViruses encode vitamin K–based #redox modules for #lipid modification doi.org/10.1073/pnas...
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Giant viruses encode vitamin K–based redox modules for lipid modification | PNAS
Viruses with large DNA genomes often carry auxiliary metabolic genes that reprogram host physiology, yet their contributions to host redox and memb...
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Anouk Willemsen @willemsenanouk.bsky.social · 17/07/2026
Isolation of a Cohort of #giantViruses From Above the Arctic Circle in Northern Norway doi.org/10.1111/1462...
doi.org
Isolation of a Cohort of Giant Viruses From Above the Arctic Circle in Northern Norway
(1) From July 2021 and May 2025 441 marine, freshwater, and soil samples were collected between longitudes 12.79° W to 23.68° E and latitudes 67.88° N to 83.90° N. (2) All samples were screened for v....
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Anouk Willemsen @willemsenanouk.bsky.social · 08/07/2026
Great feeling delivering a talk at #VoM2026, what a stage! If you are into #giant viral entities, be sure to visit the team's posters 👇 55: Laura (MGEs and competition) 154: Daniela (Tupanvirus gene expression) 162: Dominik (Ecological interactions) 208: Büşra (Viruses and jumbo phages in FMT)
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Anouk Willemsen @willemsenanouk.bsky.social · 08/07/2026
Last week Elia (an @euerasmusplus.bsky.social master student) defended his thesis focused on #Tupanvirus infection and amoebal defence mechanisms. He now goes back to Radboud Univ. to pursue a PhD! It was a pleasure hosting him and can't wait to see what he does next!
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Anouk Willemsen @willemsenanouk.bsky.social · 19/06/2026
Genetic manipulation of a #giantVirus -associated #virophage by Jingjie Chen, Hiroyuki Ogata, and Hiroyuki Hikida (cls.kuicr.kyoto-u.ac.jp/en/) @KyotoUniversity doi.org/10.64898/202...
doi.org
Genetic manipulation of a giant virus-associated virophage
Virophages are double-stranded DNA viruses that hyperparasitize giant viruses infecting unicellular eukaryotes. Parasitization by virophages often reduces the replication of giant viruses, thereby mod...
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Mart Krupovic @mkrupovic.bsky.social · 11/05/2026
With Eugene Koonin, we wrote a rather comprehensive review on the origin, evolution and organization of the #virosphere. We describe all 10 viral realms and the logic behind them, and so much more. Check it out! comptes-rendus.academie-sciences.fr/biologies/ar...
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Anouk Willemsen @willemsenanouk.bsky.social · 03/06/2026
www.linkedin.com/posts/univer...
linkedin.com
University of Vienna – Anouk Willemsen, Assistant Professor at CeMESS | University of Vienna Philanthropy
When do viruses become a threat? 🧬 Viruses are all around us, and most go unnoticed. With new viral generations emerging daily, just a few mutations under the right conditions can change everything. ...
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Anouk Willemsen @willemsenanouk.bsky.social · 30/05/2026
Indeed. Was a fun piece to work on, with such a great team of people and friends!
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Hugo Bisio @molbiolgv.bsky.social · 29/05/2026
Just published! Check out our review of the Nucleocytoviricota infection cycle. Great teamwork! @mkrupovic.bsky.social @willemsenanouk.bsky.social @fischerlab.bsky.social @puffy-virus.bsky.social
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Anouk Willemsen @willemsenanouk.bsky.social · 22/05/2026
... meaning that while NCVs themselves do not rank among the most central (neither by degree or betweenness), NCV-connected microbial contigs assume dramatically elevated centrality compared to both unconnected microbes and the NCVs themselves. So, NCVs are key mediators of interaction. 4/4
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Anouk Willemsen @willemsenanouk.bsky.social · 22/05/2026
Through a multi-layered #networkAnalysis (looking at gene sharing, co-occurrence, and integration), we demonstrate nucleocytoviruses mediate the centrality of key interaction-hubs, and entities associated with NCVs strongly coincide with more central positions... 3/4
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Anouk Willemsen @willemsenanouk.bsky.social · 22/05/2026
Led by @dominikluecking.bsky.social , we reconstructed high-quality genomes from diverse Waste-water treatment plants (61 novel nucleocytoviruses, 15 virophages and 14 polinton-like viruses). We aimed to study interactions among the players in this complex ecosystems.... 2/4
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Anouk Willemsen @willemsenanouk.bsky.social · 22/05/2026
New Work out! A multilayered network reveals the centrality of newly discovered #Nucleocytoviricota in wastewater treatment plant communities w/ @dominikluecking.bsky.social & @amanzanom.bsky.social doi.org/10.64898/202... @erc.europa.eu @univie.ac.at @dome-vienna.bsky.social 1/4
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Anouk Willemsen @willemsenanouk.bsky.social · 15/05/2026
Reposting for #VirEvol
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Anouk Willemsen @willemsenanouk.bsky.social · 16/04/2026
Genomic islands in #Nucleocytoviricota. "[...] 37% of genomic islands are enriched in bacterial homologs, and several exhibit striking synteny with genomic regions recovered from environmentally co-occurring bacterial genomes [...]" doi.org/10.64898/202...
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Anita Meier @anitafmeier.bsky.social · 27/02/2026
Most viruses rely on the host to provide the entire translation machinery. However, giant viruses have evolved to encode part of the machinery themselves. Latest discovery: mimivirus (APMV) encodes its own initiation factor (vIF4F) and specifically promotes translation of viral mRNA!
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Maria Dzunkova @dzunkovam.bsky.social · 23/02/2026
We had a special speaker today at @i2sysbio.es , Anouk Willemsen @willemsenanouk.bsky.social. I have known her since my PhD and I truly admire her work on giant viruses #viruses #microsky
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Anouk Willemsen @willemsenanouk.bsky.social · 27/01/2026
For some reason, this didn't show up automatically in #giantVirus Single-cell genomics reveals complex microbial and viral associations in ciliates and testate amoebae "The frequent co-occurrence of giant viruses and microbial symbionts, especially in amoebae, suggests multipartite interactions"
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Anouk Willemsen @willemsenanouk.bsky.social · 15/12/2025
On our way to the 6th Ringberg Symposium on Giant Virus Biology #ringbergGV2025
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Anouk Willemsen @willemsenanouk.bsky.social · 10/12/2025
We also had bioinformatic exercises going from sequence download to tree building, inference of spillover events and recombination. Shout-out to @amanzanom.bsky.social , @dominikluecking.bsky.social & Büşra for leading this hands-on part. Definitely looking forward to the next edition! 2/2
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Anouk Willemsen @willemsenanouk.bsky.social · 10/12/2025
Last week we wrapped up the first edition of the Virus evolution and ecology course under the umbrella of the brand new Master in Microbiome Science offered @univie.ac.at. We learned about viruses, their evolution, and their ecological impact across different ecosystems. 1/2 #VirEvol
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Emmanuele Severi @emmseveri.bsky.social · 27/11/2025
#microsky #phagesky #phage #virus academic.oup.com/nar/advance-...
academic.oup.com
Virus taxonomy: the database of the International Committee on Taxonomy of Viruses
Abstract. Taxonomic classification underlies all biological science and is the basis for comparative analysis of biological organisms and therefore our und
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Anouk Willemsen @willemsenanouk.bsky.social · 25/11/2025
Strain-level diversity of #giantViruses infecting #chlorarachniophyte #algae in the subtropical North Pacific by @fischerlab.bsky.social doi.org/10.1101/2025...
doi.org
Strain-level diversity of giant viruses infecting chlorarachniophyte algae in the subtropical North Pacific
Giant DNA viruses are ubiquitous among unicellular eukaryotes and occur in marine, freshwater, and terrestrial environments. Despite intense metagenomic data mining, their strain-level diversity remai...
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Johana Rotterova @micrott.bsky.social · 19/11/2025
Is it a flagellate? A tiny ball with tentacles? Contamination in my ciliate culture? NEW SUPERGROUP OF EUKARYOTES? Yes to all 4! Meet Solarion - just out in #Nature doi.org/10.1038/s415... Huge congrats to Marek Valt, Cepicka Lab & the star team! Very happy to be part of this project. #ProtistsOnSky
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Anouk Willemsen @willemsenanouk.bsky.social · 17/09/2025
Reposting for #VirEvol
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Anouk Willemsen @willemsenanouk.bsky.social · 09/09/2025
Proud moment to see the first Master student of the team (Lotte Mayer) successfully defend her Master's thesis work digging into viral factories of #giantViruses. A link to part of her work: doi.org/10.1101/2025... @erc.europa.eu @univie.ac.at @cemess.bsky.social @dome-vienna.bsky.social
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Anouk Willemsen @willemsenanouk.bsky.social · 26/08/2025
Last week #ESEB2025 wrapped up. It was a great opportunity to chat with colleagues, hear about great evolutionary research, present the group's work, and be a proud PI of Laura, who did a great job presenting her PhD work! Two years to go until next ESEB! @eseb2025.bsky.social
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Karolin Luger @nucleosomepolice.bsky.social · 26/07/2025
our paper is online! rdcu.be/exXBX . Who would have thought that some #giantviruses not only have #histones, but even histone variants that make weird #nucleosomes (pdb 9CVT). Fantastic work from Ale Villalta and Chelsea Toner, with Hugo Bisio @molbiolgv.bsky.social and Chantal Abergel
rdcu.be
Melbournevirus encodes a shorter H2B-H2A doublet histone variant that forms structurally distinct nucleosome structures
Nature Communications - Melbournevirus encodes a conserved shorter H2B-H2A doublet variant. Here the authors report a cryo-EM structure of a nucleosome-like particle reconstituted with viral H4-H3...
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Anouk Willemsen @willemsenanouk.bsky.social · 14/07/2025
Heat Shock Protein 70 (AKA HSP70) in Mimiviridae and Phycodnaviridae likely originated from horizontal transfer from their protist hosts. By @sfelena.bsky.social & @amaachi.bsky.social doi.org/10.1101/2025... #giantVirus #VirEvol
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Multiple origins, one function: evolutionary pathways of HSP70 proteins in viruses
Heat shock proteins 70 (HSP70) are highly conserved molecular chaperones found across all domains of life, where they play essential roles in cellular stress responses. While HSP70 homologs have been ...
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Anouk Willemsen @willemsenanouk.bsky.social · 13/06/2025
Out now in its final peer-reviewed form @asm.org's Journal of Virology! doi.org/10.1128/jvi.... @dome-vienna.bsky.social @erc.europa.eu @amersocvirology.bsky.social
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Anouk Willemsen @willemsenanouk.bsky.social · 08/05/2025
Thanks for the comment! Originally we did write BONCAT in our manuscript. With your comment as support we might still be able to change it back in the final version.
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Anouk Willemsen @willemsenanouk.bsky.social · 08/05/2025
When transported outside of the viral factory, the translation of viral mRNA takes place in a well-defined ring surrounding it. We expect these methods to be widely applicable to other viruses for the visualisation and quantification of RNA molecules. 4/4
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Anouk Willemsen @willemsenanouk.bsky.social · 08/05/2025
While viral mRNA localisation changes depending on the infection stage, transcription occurs at well-defined spots within the viral factory. The original viral cores released within the cytoplasm most likely define these spots. 3/4
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Anouk Willemsen @willemsenanouk.bsky.social · 08/05/2025
Combined with other labelling techniques, we show the #Mimivirus transcription and translation sites during an infection cycle in the amoeba host cell. 2/4
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Anouk Willemsen @willemsenanouk.bsky.social · 08/05/2025
New work out! Spearheaded by Lotte, we have developed a single-molecule messenger RNA fluorescence in situ hybridisation (smFISH) protocol for #giantViruses in an #Acanthamoeba host. doi.org/10.1101/2025... 1/4 #ProtistsOnSky #MicroSky @dome-vienna.bsky.social @cemess.bsky.social @erc.europa.eu
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Karolin Luger @nucleosomepolice.bsky.social · 16/01/2025
by now you probably know that #giantviruses have #histones, but some also have histone variants! Check out our latest preprint on an essential H2B-H2A histone variant in Melbournevirus - a fantastic collaboration with the Abergel Lab, spearheaded by Ale Villalta. www.biorxiv.org/content/10.1...
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Cameron Thrash @jcamthrash.bsky.social · 10/01/2025
Pacmanvirus isolated from the Lost City hydrothermal field extends the concept of transpoviron beyond the family Mimiviridae academic.oup.com/ismej/advanc... #jcampubs
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fischerlab.bsky.social @fischerlab.bsky.social · 09/12/2024
Looking for a postdoc in environmental virology? Fascinated by giant viruses and their glycobiology? We have a position available at the MPI for Marine Microbiology! @mpimarinemicrobio.bsky.social @maxplanck.de career.mpi-bremen.de/jobposting/8...
career.mpi-bremen.de
Post-Doc Protist Viruses
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Anouk Willemsen @willemsenanouk.bsky.social · 01/12/2024
Don't forget the #giantVirus tag! With it, it will get collected in the Giant virus feed
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Anouk Willemsen @willemsenanouk.bsky.social · 12/11/2024
🖐️
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Anouk Willemsen @willemsenanouk.bsky.social · 10/11/2024
also @rubengonzalez.bsky.social @sfelena.bsky.social
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Anouk Willemsen @willemsenanouk.bsky.social · 10/11/2024
🖐️
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Anouk Willemsen @willemsenanouk.bsky.social · 10/11/2024
Reposting for #VirEvol and #giantViruses
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Karolin Luger @nucleosomepolice.bsky.social · 05/11/2024
there is a new #giantvirus in town! and it speaks Finnish! www.biorxiv.org/content/10.1...
biorxiv.org
Genomic and structural insights into Jyvaskylavirus, the first giant virus isolated from Finland
Giant viruses of protists are a diverse and likely ubiquitous group of organisms. Here, we describe Jyvaskylavirus, the first giant virus isolated from Finland. This clade B marseillevirus was found i...
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Karolin Luger @nucleosomepolice.bsky.social · 23/10/2024
behold our paper on Medusavirus nucleosomes. Fantastic work by Chelsea Toner, @nhoitsma.bsky.social, and Sashi Weerawarana This giant virus also encodes a linker histone, more about that in the paper 🧪👩‍🔬 🧵. www.nature.com/articles/s41...
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Anouk Willemsen @willemsenanouk.bsky.social · 25/10/2024
Finally, by analyzing the new amoebal genomes, we discovered viral integrations (potentially from GVs) into some of them, indicating historical infections. Most notably some inserted major capsid proteins seem to potentially encode for intact proteins (work in progress)... Read and enjoy! 4/4
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Anouk Willemsen @willemsenanouk.bsky.social · 25/10/2024
They encode few to complete tRNA sets and even genes from the translational machinery (e.g. tRNA--ligases). The host immune system may also play a role, driving viral codon usage away from its own. Moreover, its replication site (nuclear vs. cytoplasmatic) could also play a role. 3/4
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