Tomas Hessler

Highly mutagenic continuous evolution in E. coli using a Φ29-based orthogonal replication system - Nature Biotechnology Mutational rates of bacterial evolution are increased using an error-prone orthogonal system.

Very happy to see this work from Fabian Rehm, Jason Chin, and team on the development of a high error-rate orthogonal DNA replication system in E. coli, thus supporting continuous hypermutation and evolution of target genes in vivo. www.nature.com/articles/s41...

📣new preprint from the phagefoundry.org team 🎉 Jessica Trinh and Catherine Mageeney (Sandia National Laboratories)!!

Systematic analysis of prophages from ~1000 Acinetobacter baumannii isolates, induction & screening. We found this 😎 looking phage with bunch of 💍💍

New paper from my group in @science.org : "A small polymerase ribozyme that can synthesise itself and its complementary strand" www.science.org/doi/10.1126/...
Outstanding work by @edogia.bsky.social

Just published: "Planetary microbiome structure and generalist-driven gene flow across disparate habitats" by @podlesny.bsky.social @chanyeong-kim.bsky.social and @jonas-bio.bsky.social www.cell.com/cell/fulltex...

See the quoted post below for a thread on the preprint!

All you want for christmas is.... transposon mutagenesis!

Our new work at @cultivarium.bsky.social screening lots of transposon vectors in lots of bacteria, from @charliegilbert.bsky.social and team.

Transposon and promoter modular parts available on Addgene (pooled library will be there soon too)

Excited to share our discovery of archaeal circular, jumbo extrachromosomal elements (up to ~535 kb genomes). One related, 409-kb genome is integrated in CH4-eating Methanoperedens, representing the largest integrative element in Archaea so far! Curious about what they are doing? See the paper

A new extreme of meiotic evolution:

✔️ 𝗻𝗼 crossovers
✔️ 𝗻𝗼 gene conversion
✔️ 𝗻𝗼𝗿𝗺𝗮𝗹 meiosis & fertility

Sex mimics clonality without becoming asexual, in the holocentric multicellular eukaryote 𝘙𝘩𝘺𝘯𝘤𝘩𝘰𝘴𝘱𝘰𝘳𝘢 𝘵𝘦𝘯𝘶𝘪𝘴.

more about it:
www.biorxiv.org/content/10.6...

A related study from Nandita’s group on gene-specific sweeps - a great idea to compare non-synonymous linkage disequilibrium (LD) vs synonymous LD! Gut microbiome show pervasive selective sweeps in carbohydrate metabolism - diet adaptation! #microsky #microbiomesky 🧪🦠
www.nature.com/articles/s41...

Identification of proteins influencing CRISPR-associated transposases for enhanced genome editing Whole-genome screening reveals strategies to boost CRISPR-associated transposase genome editing efficiency.

#microsky #synbiosky

www.science.org/doi/10.1126/...

Esther Lederberg in the laboratory in the 1950's. Credit: Estherlederberg.com

Born #OnThisDay in 1922, Esther Lederberg was the first to isolate the lambda phage in 1951. She characterised the lysogenic phase, whereby the phage are able to integrate into the bacterial genome, staying dormant. This discovery made them a model tool of study, leading to many more breakthroughs.

Do you think transporters in E. coli contribute to metabolite release? No? Explore the effect of 66 different transporter knockout mutations on the exometabolome dynamics of ~300 metabolites yourself: keio.unil.ch

Teaser: Increased proline in ΔputP
#microsky #MEvoSky

Convergent evolution of viral-like Borg archaeal extrachromosomal elements and giant eukaryotic viruses - Nature Communications Borgs are large extrachromosomal elements of anaerobic methane-oxidizing archaea. Here, via in silico protein structure prediction of ~10,000 Borg proteins, the authors reveal that Borgs share numerou...

Out now in Nature Communications: Convergent evolution of viral-like Borg archaeal extrachromosomal elements and giant eukaryotic viruses

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

@luisvalentin.bsky.social @lingdong-shi.bsky.social @martianmicrobe.bsky.social @mschoelmerich.bsky.social

Bacteriophage genome-wide transposon mutagenesis Bacteriophages have genomes that span a wide size range, are densely packed with coding sequences, and frequently encode genes of unknown function. Classical forward genetics has defined essential gen...

#microsky #phagesky

Transposon mutagenesis of jumbo #phage using an anti-CRISPR factor as selectable marker

www.biorxiv.org/content/10.1...

An archaeal genetic code with all TAG codons as pyrrolysine Multiple genetic codes developed during the evolution of eukaryotes and bacteria, yet no alternative genetic code is known for archaea. We used proteomics to confirm our prediction that certain archae...

New paper out: An archaeal genetic code with all TAG codons as pyrrolysine: www.science.org/doi/10.1126/...

Red seaweed supplementation suppresses methanogenesis in the rumen, revealing potentially advantageous traits among hydrogenotrophic bacteria - Microbiome Background Macroalgae belonging to the genus Asparagopsis have shown to reduce methane (CH4) production during rumen fermentation, while increasing feed efficiency when added to the feed of cattle. Ho...

We are thrilled to announce our latest publication in the Microbiome journal in collaboration with
@thehesslab.bsky.social
Supplementation with red seaweed in cows reduces methane and induces previously uncharacterized hydrogenotropic bacteria.
microbiomejournal.biomedcentral.com/articles/10....

Very happy to share our recent work @cultivarium.bsky.social on genetic tools for Ideonella sakaiensis, a (Betaproteo-)bacterium that degrades PET plastic.

We identified a plasmid vector for the strain and generated a large RB-TnSeq library, screening for genes impacting plastic degradation.

Selection and transmission of the gut microbiome alone can shift mammalian behavior Nature Communications - Here, the authors present evidence that the gut microbiome alone, without changes in the host genome, can shape how animals respond to selection, identifying a bacterium and...

We selected the laziest mouse at each round to inoculate the next batch of germfree mice: over rounds of selection and passaging, behavior shifted without changes to the mouse genome: rdcu.be/eM3rO
🦠🧫

The tRNA epitranscriptomic landscape and RNA modification enzymes in Vibrio cholerae Author summary This study charts the first genome-wide map of transfer RNA (tRNA) modifications in the cholera pathogen, Vibrio cholerae, revealing how chemical marks on tRNAs shape translation and st...

Our new paper maps the tRNA modification landscape in Vibrio cholerae! 💫
We describe differences from E. coli and discuss links to decoding of stress-related codons 🦠
Huge thanks to amazing co-authors and collaborators!
@plos.org #rnasky #microsky #tRNAmodifications

How do spontaneous mutations arise?

In this latest #GENETICS review, Susan Lovett and @thalia.bsky.social provide a detailed overview of bacterial genetics experiments instrumental in understanding how genomes change. buff.ly/CXJnTqn

VACANCY - Independent research fellowships leading to tenured positions

We’re inviting applications from outstanding researchers who either hold, or wish to apply for, Independent Research Fellowships.

APPLICATION DEADLINE: 10 November 2025

Click here to apply: jic.link/Fellows

A miniature CRISPR–Cas10 enzyme confers immunity by inhibitory signalling - Nature Panoptes, an anti-phage defence system against virus-mediated immune suppression, is revealed.

Now online at @nature.com we show how the Panoptes defense system protects against viruses that attempt immune evasion - and expands our understanding of the role of oligonucleotides in immunity.

Check out this work co-led with @benadler.bsky.social here:

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

Most plasmids described in E. coli are small compared to the megaplasmids we identified here! Check out the preprint if you want to learn about these mysterious large elements and their potential functions 🧬. I’m very grateful to have had the opportunity to work on this in @banfieldlab.bsky.social

📢 New preprint on work by my first PhD student William Pallier.

Recovery of microbial ecophysiology and carbon accrual functions in peatlands under restoration.

We demonstrate that microbial ecophysiology predictably changes with peatland ecosystem health.

www.biorxiv.org/content/10.1...

Phage-mediated lysis does not determine Cutibacterium acnes colonization on human skin Despite Cutibacterium acnes being the most abundant and prevalent bacteria on human skin, only a single type of phage has been identified that infects this host. Here, we leverage this one-to-one syst...

How much of selection in human microbiomes is driven by phage?

Excited to share our latest, led by A. Delphine Tripp, showing a case where phage is just not that important:

Phage-mediated lysis does not determine Cutibacterium acnes colonization on human skin

www.biorxiv.org/content/10.1...

🧵

Phages with a broad host range are common across ecosystems - Nature Microbiology Proximity-ligation-based sequencing from 111 samples and 5 environments reveals that a substantial proportion of phages infect multiple species.

You like phages ? In this publication, we use metaHiC and our new version of the MetaTOR pipeline to challenge the traditional view of phages with a narrow host range.
@rkoszul.bsky.social @natmicrobiol.nature.com @cnrs.fr @institutpasteur.bsky.social

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

Assistant Professor Plant-Microbe Interactions We seek a creative, collaborative, and visionary plant biologist to establish an internationally recognized research program at the forefront of plant-microbe interactions aimed at understanding how t...

The Department of Biology at Colorado State University is hiring an Assistant Professor in the area of plant-microbe interactions! Please spread the word!

jobs.colostate.edu/postings/165...

GPU-accelerated homology search with MMseqs2 - Nature Methods Graphics processing unit-accelerated MMseqs2 offers tremendous speedups for homology retrieval from metagenomic databases, query-centered multiple sequence alignment generation for structure predictio...

GPU-accelerated MMseqs2 offers tremendous speedup for homology retrieval, protein structure prediction with ColabFold, and protein structure search with Foldseek. @martinsteinegger.bsky.social @milot.bsky.social @machine.learning.bio

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

AlphaFold model of the complex formed between HK2 and the SOX10 5′UTR (189–204 nts). The predicted RNA structure is shown in cyan, and HK2 protein is shown in green. HK2 residues and SOX10 mRNA nucleotides at the interaction interface are highlighted in red. Inset: schematic representation of the secondary structure of the SOX10 5′UTR (189–204 nts) predicted by Mfold, with the putative HK2-binding region (194–198 nts) marked in red.

Hexokinase 2 (HK2) is known for its metabolic role in #glycolysis. This study shows that it also functions as an #RNAbindingProtein that regulates mRNA translation, particularly of SOX10, promoting #melanoma cell proliferation independently of glycolysis @plosbiology.org 🧪 plos.io/3ViI1qL

Naiavirus: an enveloped giant virus with a pleomorphic, flexible tail - Nature Communications Rodrigues and Queiroz et al. report the discovery of Naiavirus, the largest enveloped virus, isolated from a Brazil biome. With an oval capsid and flexible tail, its giant genome holds many novel gene...

Naiavirus: an enveloped giant virus with a pleomorphic, flexible tail
nature.com/articles/s41467-025-63463-6

Programmable antisense oligomers for phage functional genomics - Nature Establishing antisense oligomers as versatile, non-genetic tools to silence phage mRNAs opens applications in basic research and biotechnology, as shown by identifying essential factors for propagation of the nucleus-forming jumbo phage ΦKZ such as the RNase H-like protein ΦKZ155.

Nature research paper: Programmable antisense oligomers for phage functional genomics

go.nature.com/46b1XAQ