Kotaro Chihara
@kochihara.bsky.social
Molecular biology in phage-bacteria interactions | Postdoc in the phage engineering group at NIID, Japan
Reposted by Kotaro Chihara
Out Now! A phage protein screen identifies triggers of the bacterial innate immune system #MicroSky
A phage protein screen identifies triggers of the bacterial innate immune system
Nature Microbiology, Published online: 16 January 2026; doi:10.1038/s41564-025-02239-6A library of 400 phage protein-coding genes is used to find a trove of antiphage systems, revealing systems that target tail fibre and major capsid proteins.
go.nature.com
January 16, 2026 at 4:53 PM
Out Now! A phage protein screen identifies triggers of the bacterial innate immune system #MicroSky
Reposted by Kotaro Chihara
Happy to share our recent preprint:
"DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity"
www.biorxiv.org/content/10.6...
@spp2330.bsky.social, @mibinet.bsky.social, @dfg.de @hhu.de @fzj.bsky.social
"DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity"
www.biorxiv.org/content/10.6...
@spp2330.bsky.social, @mibinet.bsky.social, @dfg.de @hhu.de @fzj.bsky.social
January 14, 2026 at 8:57 AM
Happy to share our recent preprint:
"DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity"
www.biorxiv.org/content/10.6...
@spp2330.bsky.social, @mibinet.bsky.social, @dfg.de @hhu.de @fzj.bsky.social
"DNA-intercalating antiphage molecules trigger abortive infection through mutual destruction and synergize with bacterial immunity"
www.biorxiv.org/content/10.6...
@spp2330.bsky.social, @mibinet.bsky.social, @dfg.de @hhu.de @fzj.bsky.social
Reposted by Kotaro Chihara
Phold's manuscript is now available @narjournal.bsky.social thanks to @susiegriggo.bsky.social @npbhavya.bsky.social @vijinim.bsky.social @linsalrob.bsky.social @martinsteinegger.bsky.social @milot.bsky.social @eunbelivable.bsky.social & others not on bsky #phagesky academic.oup.com/nar/article/...
January 14, 2026 at 5:10 AM
Phold's manuscript is now available @narjournal.bsky.social thanks to @susiegriggo.bsky.social @npbhavya.bsky.social @vijinim.bsky.social @linsalrob.bsky.social @martinsteinegger.bsky.social @milot.bsky.social @eunbelivable.bsky.social & others not on bsky #phagesky academic.oup.com/nar/article/...
Reposted by Kotaro Chihara
Secret life of prophages: template-directed synthesis of DNA superstructures via prophage activation and rolling circle replication in bacterial biofilms
bioRxiv by Gabriel Antonio S. Minero et al
with @thethormannden.bsky.social, Rikke Louise Meyer
www.biorxiv.org/content/10.6...
bioRxiv by Gabriel Antonio S. Minero et al
with @thethormannden.bsky.social, Rikke Louise Meyer
www.biorxiv.org/content/10.6...
Secret life of prophages: template-directed synthesis of DNA superstructures via prophage activation and rolling circle replication in bacterial biofilms
Extracellular DNA (eDNA) plays crucial roles in biofilm formation and function, yet the role of bacteriophages (phages) in controlling eDNA synthesis, structure and activity remains obscure. Here, we ...
www.biorxiv.org
January 11, 2026 at 3:12 PM
Secret life of prophages: template-directed synthesis of DNA superstructures via prophage activation and rolling circle replication in bacterial biofilms
bioRxiv by Gabriel Antonio S. Minero et al
with @thethormannden.bsky.social, Rikke Louise Meyer
www.biorxiv.org/content/10.6...
bioRxiv by Gabriel Antonio S. Minero et al
with @thethormannden.bsky.social, Rikke Louise Meyer
www.biorxiv.org/content/10.6...
Reposted by Kotaro Chihara
Only in Shenzhen: Science Nature coffee bar. If you’ve published in @science.org or @nature.com, they give you coffee for free. 100% real!
January 10, 2026 at 10:43 AM
Only in Shenzhen: Science Nature coffee bar. If you’ve published in @science.org or @nature.com, they give you coffee for free. 100% real!
Very fascinating! can’t help wondering whether mimivirus tRNAs — together with its local translation compartment — might play a failsafe role against host immunity.
www.nature.com/articles/s41564-025-02234-x
www.nature.com/articles/s41564-025-02234-x
Client Challenge
www.nature.com
January 9, 2026 at 12:29 PM
Very fascinating! can’t help wondering whether mimivirus tRNAs — together with its local translation compartment — might play a failsafe role against host immunity.
www.nature.com/articles/s41564-025-02234-x
www.nature.com/articles/s41564-025-02234-x
Reposted by Kotaro Chihara
Our paper is out! Hiding in plain sight among Cas12a nucleases, Cas12a3 cleaves not its RNA target but the 3′ ends of tRNA. Huge thanks to all who made this possible, especially the Beisel lab, Biao & Dirk for the structure, & @sebastianglatt.bsky.social for all things tRNA. doi.org/10.1038/s415...
RNA-triggered Cas12a3 cleaves tRNA tails to execute bacterial immunity - Nature
Cas12a3 nucleases constitute a distinct clade of type V CRISPR–Cas bacterial immune systems that preferentially cleave the 3′ tails of tRNAs after recognition of target RNA to induce growth arres...
www.nature.com
January 7, 2026 at 4:15 PM
Our paper is out! Hiding in plain sight among Cas12a nucleases, Cas12a3 cleaves not its RNA target but the 3′ ends of tRNA. Huge thanks to all who made this possible, especially the Beisel lab, Biao & Dirk for the structure, & @sebastianglatt.bsky.social for all things tRNA. doi.org/10.1038/s415...
Reposted by Kotaro Chihara
A systematic analysis of STAND NTPases and their associated sensor domains in bacterial immunity 🤯 Mind-blowing work !
Diverse bacterial pattern recognition receptors sense the conserved phage proteome
Recognition of foreign molecules inside cells is critical for immunity in all domains of life. Proteins of the STAND NTPase superfamily, including eukaryotic nucleotide-binding oligomerization domain ...
www.biorxiv.org
January 5, 2026 at 12:17 PM
A systematic analysis of STAND NTPases and their associated sensor domains in bacterial immunity 🤯 Mind-blowing work !
Reposted by Kotaro Chihara
Do viruses use RNA to rewire bacteria?
Yes!
In our paper in @cp-molcell.bsky.social RIL-seq reveals interkingdom RNA interactions during λ infection. Phages don’t just encode proteins, they use small RNAs to hijack bacterial replication and fine-tune infection.
#RNA #Phage
doi.org/10.1016/j.mo...
Yes!
In our paper in @cp-molcell.bsky.social RIL-seq reveals interkingdom RNA interactions during λ infection. Phages don’t just encode proteins, they use small RNAs to hijack bacterial replication and fine-tune infection.
#RNA #Phage
doi.org/10.1016/j.mo...
Phage-encoded small RNA hijacks host replication machinery to support the phage lytic cycle
Using RIL-seq, Silverman et al. map the RNA interactome of E. coli during phage lambda
infection and uncover a conserved phage-encoded sRNA that activates host replication
machinery. Their findings re...
www.cell.com
December 19, 2025 at 6:43 AM
Do viruses use RNA to rewire bacteria?
Yes!
In our paper in @cp-molcell.bsky.social RIL-seq reveals interkingdom RNA interactions during λ infection. Phages don’t just encode proteins, they use small RNAs to hijack bacterial replication and fine-tune infection.
#RNA #Phage
doi.org/10.1016/j.mo...
Yes!
In our paper in @cp-molcell.bsky.social RIL-seq reveals interkingdom RNA interactions during λ infection. Phages don’t just encode proteins, they use small RNAs to hijack bacterial replication and fine-tune infection.
#RNA #Phage
doi.org/10.1016/j.mo...
Reposted by Kotaro Chihara
Phages are full of genes of unknown function that are likely adaptive in specific conditions.
New preprint: Phage TnSeq identifies essential genes rapidly and knocks all non-essentials. We would like to send a pool of phiKZ mutants to anyone wanting it! Reach out
tinyurl.com/bdcfrejh
New preprint: Phage TnSeq identifies essential genes rapidly and knocks all non-essentials. We would like to send a pool of phiKZ mutants to anyone wanting it! Reach out
tinyurl.com/bdcfrejh
December 8, 2025 at 3:04 PM
Phages are full of genes of unknown function that are likely adaptive in specific conditions.
New preprint: Phage TnSeq identifies essential genes rapidly and knocks all non-essentials. We would like to send a pool of phiKZ mutants to anyone wanting it! Reach out
tinyurl.com/bdcfrejh
New preprint: Phage TnSeq identifies essential genes rapidly and knocks all non-essentials. We would like to send a pool of phiKZ mutants to anyone wanting it! Reach out
tinyurl.com/bdcfrejh
Reposted by Kotaro Chihara
💾 ABRicate 1.2.0 has been released!
This 'oversight' lasted 6 years, but with help from @finlaym.bsky.social we got CI working and updated all the databases. #bioconda #conda #bioinformatics #microbiology #genomics
github.com/tseemann/abr...
This 'oversight' lasted 6 years, but with help from @finlaym.bsky.social we got CI working and updated all the databases. #bioconda #conda #bioinformatics #microbiology #genomics
github.com/tseemann/abr...
Releases · tseemann/abricate
:mag_right: :pill: Mass screening of contigs for antimicrobial and virulence genes - tseemann/abricate
github.com
December 5, 2025 at 11:27 PM
💾 ABRicate 1.2.0 has been released!
This 'oversight' lasted 6 years, but with help from @finlaym.bsky.social we got CI working and updated all the databases. #bioconda #conda #bioinformatics #microbiology #genomics
github.com/tseemann/abr...
This 'oversight' lasted 6 years, but with help from @finlaym.bsky.social we got CI working and updated all the databases. #bioconda #conda #bioinformatics #microbiology #genomics
github.com/tseemann/abr...
Reposted by Kotaro Chihara
Thrilled to share that my postdoc research is published today in @science.org! We found that DNA repair uses cohesin complexes to build new chromatin loops that guide the homology search and boost accurate repair! 1/n
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Cohesin drives chromatin scanning during the RAD51-mediated homology search
Cohesin folds genomes into chromatin loops, the roles of which are under debate. We found that double-strand breaks (DSBs) induce de novo formation of chromatin loops in human cells, with the loop bas...
www.science.org
December 4, 2025 at 9:50 PM
Thrilled to share that my postdoc research is published today in @science.org! We found that DNA repair uses cohesin complexes to build new chromatin loops that guide the homology search and boost accurate repair! 1/n
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Kotaro Chihara
Preprint: Systematic discovery of TIR-based immune signaling systems in bacteria
Conservation of TIR-derived signals accross the tree of life! We found bacterial TIR immune systems that signal via canonical cADPR (like in humans) and 2'cADPR (a plant immune signal).
Documented 11 Thoeris types
Conservation of TIR-derived signals accross the tree of life! We found bacterial TIR immune systems that signal via canonical cADPR (like in humans) and 2'cADPR (a plant immune signal).
Documented 11 Thoeris types
December 4, 2025 at 1:56 PM
Preprint: Systematic discovery of TIR-based immune signaling systems in bacteria
Conservation of TIR-derived signals accross the tree of life! We found bacterial TIR immune systems that signal via canonical cADPR (like in humans) and 2'cADPR (a plant immune signal).
Documented 11 Thoeris types
Conservation of TIR-derived signals accross the tree of life! We found bacterial TIR immune systems that signal via canonical cADPR (like in humans) and 2'cADPR (a plant immune signal).
Documented 11 Thoeris types
Reposted by Kotaro Chihara
Check this out for the 2026 SISB (phage defense) meeting in NYC. Mark your calendar! (and note the Zoom option, if needed)
sisb2026.rockefeller.edu
sisb2026.rockefeller.edu
SISB2026
sisb2026.rockefeller.edu
December 1, 2025 at 11:44 PM
Check this out for the 2026 SISB (phage defense) meeting in NYC. Mark your calendar! (and note the Zoom option, if needed)
sisb2026.rockefeller.edu
sisb2026.rockefeller.edu
Reposted by Kotaro Chihara
Our SPARHA story is out in Nature Communications!
doi.org/10.1038/s414...
We investigated a new short pAgo-HNH defense system, showing that it assembles into filaments degrading cellular DNA, inducing abortive infection, resolved their structure, and uncovered the activation mechanism 🧵
doi.org/10.1038/s414...
We investigated a new short pAgo-HNH defense system, showing that it assembles into filaments degrading cellular DNA, inducing abortive infection, resolved their structure, and uncovered the activation mechanism 🧵
December 1, 2025 at 8:38 AM
Our SPARHA story is out in Nature Communications!
doi.org/10.1038/s414...
We investigated a new short pAgo-HNH defense system, showing that it assembles into filaments degrading cellular DNA, inducing abortive infection, resolved their structure, and uncovered the activation mechanism 🧵
doi.org/10.1038/s414...
We investigated a new short pAgo-HNH defense system, showing that it assembles into filaments degrading cellular DNA, inducing abortive infection, resolved their structure, and uncovered the activation mechanism 🧵
Reposted by Kotaro Chihara
🧬🛡️How are new immune mechanisms created?
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
November 27, 2025 at 9:35 AM
🧬🛡️How are new immune mechanisms created?
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
We show how Lamassu antiphage system, originated from a DNA-repair complex and evolved into a compact and modular immune machine, wt Dinshaw Patel lab in @pnas.org.
👏 @matthieu-haudiquet.bsky.social, Arpita Chakravarti & all authors!
doi.org/10.1073/pnas...
Reposted by Kotaro Chihara
⭐ NAR Breakthrough! ⭐
🔬 New study reveals how the Retron-Eco7 system helps bacteria sense and fight phage attacks, identifying a clever immune-sensing mechanism in the bacteria–phage arms race.
🧬 Read more: doi.org/10.1093/nar/...
#NARBreakthrough #Microbiology #PhageBiology #BacterialDefense
🔬 New study reveals how the Retron-Eco7 system helps bacteria sense and fight phage attacks, identifying a clever immune-sensing mechanism in the bacteria–phage arms race.
🧬 Read more: doi.org/10.1093/nar/...
#NARBreakthrough #Microbiology #PhageBiology #BacterialDefense
November 24, 2025 at 6:16 PM
⭐ NAR Breakthrough! ⭐
🔬 New study reveals how the Retron-Eco7 system helps bacteria sense and fight phage attacks, identifying a clever immune-sensing mechanism in the bacteria–phage arms race.
🧬 Read more: doi.org/10.1093/nar/...
#NARBreakthrough #Microbiology #PhageBiology #BacterialDefense
🔬 New study reveals how the Retron-Eco7 system helps bacteria sense and fight phage attacks, identifying a clever immune-sensing mechanism in the bacteria–phage arms race.
🧬 Read more: doi.org/10.1093/nar/...
#NARBreakthrough #Microbiology #PhageBiology #BacterialDefense
Reposted by Kotaro Chihara
KlebPhaCol paper is now out! Go check it out and see all that we offer.
And when ready, visit our website for more: www.klebphacol.org
And when ready, visit our website for more: www.klebphacol.org
November 22, 2025 at 6:19 PM
KlebPhaCol paper is now out! Go check it out and see all that we offer.
And when ready, visit our website for more: www.klebphacol.org
And when ready, visit our website for more: www.klebphacol.org
Reposted by Kotaro Chihara
#microsky #phagesky #phage
Anyone who’s tried deleting prophages in the lab by HR knows the difficulties of the task. Here we have an example of how HR-mediated natural transformation might hit the same hurdle in a more native context.
academic.oup.com/mbe/article/...
Anyone who’s tried deleting prophages in the lab by HR knows the difficulties of the task. Here we have an example of how HR-mediated natural transformation might hit the same hurdle in a more native context.
academic.oup.com/mbe/article/...
Chromosomal Curing Drives an Arms Race Between Bacterial Transformation and Prophage
Abstract. Transformation occurs when bacteria import exogenous DNA via the competence machinery and integrate it into their genome through homologous recom
academic.oup.com
November 23, 2025 at 4:39 PM
#microsky #phagesky #phage
Anyone who’s tried deleting prophages in the lab by HR knows the difficulties of the task. Here we have an example of how HR-mediated natural transformation might hit the same hurdle in a more native context.
academic.oup.com/mbe/article/...
Anyone who’s tried deleting prophages in the lab by HR knows the difficulties of the task. Here we have an example of how HR-mediated natural transformation might hit the same hurdle in a more native context.
academic.oup.com/mbe/article/...
Reposted by Kotaro Chihara
Excited to share our new study! Great fun working again with my good friend @stephenrgarrett.bsky.social — always a highlight! Huge thanks to fantastic co-authors @samkaytucker.bsky.social, @drandyjroe.bsky.social and our star technician Vojtech Pavelka. academic.oup.com/nargab/artic...
November 21, 2025 at 5:45 PM
Excited to share our new study! Great fun working again with my good friend @stephenrgarrett.bsky.social — always a highlight! Huge thanks to fantastic co-authors @samkaytucker.bsky.social, @drandyjroe.bsky.social and our star technician Vojtech Pavelka. academic.oup.com/nargab/artic...
Reposted by Kotaro Chihara
🚀New preprint from our lab!
I am very excited to finally share what has been the main focus of my PhD for the past almost 3 years! It is about viral dark matter and a powerful tool we built to shed light on it. 🧬💡
Continue reading (🧵)
I am very excited to finally share what has been the main focus of my PhD for the past almost 3 years! It is about viral dark matter and a powerful tool we built to shed light on it. 🧬💡
Continue reading (🧵)
November 20, 2025 at 6:52 PM
🚀New preprint from our lab!
I am very excited to finally share what has been the main focus of my PhD for the past almost 3 years! It is about viral dark matter and a powerful tool we built to shed light on it. 🧬💡
Continue reading (🧵)
I am very excited to finally share what has been the main focus of my PhD for the past almost 3 years! It is about viral dark matter and a powerful tool we built to shed light on it. 🧬💡
Continue reading (🧵)
Reposted by Kotaro Chihara
🚨Preprint alert - this is a big one! We transfer the revolutionary power of TnSeq to bacteriophages.
Our HIDEN-SEQ links the "dark matter" genes of your favorite phage to any selectable phenotype, guiding the path from fun observations to molecular mechanisms.
A thread 1/8
Our HIDEN-SEQ links the "dark matter" genes of your favorite phage to any selectable phenotype, guiding the path from fun observations to molecular mechanisms.
A thread 1/8
November 20, 2025 at 8:40 PM
🚨Preprint alert - this is a big one! We transfer the revolutionary power of TnSeq to bacteriophages.
Our HIDEN-SEQ links the "dark matter" genes of your favorite phage to any selectable phenotype, guiding the path from fun observations to molecular mechanisms.
A thread 1/8
Our HIDEN-SEQ links the "dark matter" genes of your favorite phage to any selectable phenotype, guiding the path from fun observations to molecular mechanisms.
A thread 1/8
Reposted by Kotaro Chihara
Our nuclease-protease story is out! We explored a fascinating case of coevolution and modularity in prokaryotic immune systems: www.science.org/doi/10.1126/...
Thanks to wonderful coauthors/collaborators/friends, the whole @doudna-lab.bsky.social and everyone at @innovativegenomics.bsky.social
Thanks to wonderful coauthors/collaborators/friends, the whole @doudna-lab.bsky.social and everyone at @innovativegenomics.bsky.social
Recurrent acquisition of nuclease-protease pairs in antiviral immunity
Antiviral immune systems diversify by integrating new genes into existing pathways, creating new mechanisms of viral resistance. We identified genes encoding a predicted nuclease paired with a trypsin...
www.science.org
November 13, 2025 at 10:15 PM
Our nuclease-protease story is out! We explored a fascinating case of coevolution and modularity in prokaryotic immune systems: www.science.org/doi/10.1126/...
Thanks to wonderful coauthors/collaborators/friends, the whole @doudna-lab.bsky.social and everyone at @innovativegenomics.bsky.social
Thanks to wonderful coauthors/collaborators/friends, the whole @doudna-lab.bsky.social and everyone at @innovativegenomics.bsky.social
Reposted by Kotaro Chihara
I am so excited to share our project with you! We find prokaryotic proteases activate toxic enzymes and pores as a modular strategy in phage defense. We studied four fascinating protease-toxin pairs that are abundant across bacterial genomes:
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
Proteolytic activation of diverse antiviral defense modules in prokaryotes
Linked protease–effector modules are widespread in prokaryotic antiviral defense, yet the mechanisms of most remain poorly understood. Here we show that four of the most prevalent modules—metallo-β-la...
www.biorxiv.org
November 15, 2025 at 11:49 PM
I am so excited to share our project with you! We find prokaryotic proteases activate toxic enzymes and pores as a modular strategy in phage defense. We studied four fascinating protease-toxin pairs that are abundant across bacterial genomes:
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...