Séamus Holden 🔬🦠🧫
@seamusholden.bsky.social
Professor of Microbial Biophysics, University of Warwick. Interested in all things bacterial cell envelope, cell biophysics and advanced light microscopy. https://holdenlab.github.io/ Twitter (inactive): @seamus_holden
Preprint on the permeability of Gram+ bacterial cell wall from a few months ago. Intriguing findings, elegant methodology. Cell wall is largely impermeable to molecule sizes of mNeonGreen (27kDa) and above. How do larger secreted proteins get through? www.biorxiv.org/content/10.1... #microsky
www.biorxiv.org
February 9, 2026 at 11:30 AM
Preprint on the permeability of Gram+ bacterial cell wall from a few months ago. Intriguing findings, elegant methodology. Cell wall is largely impermeable to molecule sizes of mNeonGreen (27kDa) and above. How do larger secreted proteins get through? www.biorxiv.org/content/10.1... #microsky
Reposted by Séamus Holden 🔬🦠🧫
A gift of an article from the inimitable Colin Kleanthous as he says a moving farewell to his laboratory. A brave, unrepentant and scientifically brilliant journey is described - please have a read, friends.
www.jbc.org/article/S002...
www.jbc.org/article/S002...
Bacteriocin biophysics: From protein-protein interaction models to navigators of the bacterial cell envelope
Bacteriocins are toxins deployed by bacteria to kill their competitors. Here, I reflect
on my laboratory’s work on protein bacteriocins and their immunity proteins from Gram-negative
bacteria. We unco...
www.jbc.org
February 2, 2026 at 12:39 PM
A gift of an article from the inimitable Colin Kleanthous as he says a moving farewell to his laboratory. A brave, unrepentant and scientifically brilliant journey is described - please have a read, friends.
www.jbc.org/article/S002...
www.jbc.org/article/S002...
iCASE PhD project available in my lab, combining microscopy method development with high throughput screening of bacteria. Applications to antibiotic drug discovery and screening for new cell division proteins. Collaboration with Cairn Research #microsky #bioimaging
www.findaphd.com/phds/project...
www.findaphd.com/phds/project...
Image-based bacterial phenotyping and antimicrobial drug discovery using smart high-throughput super-resolution microscopy at University of Warwick on FindAPhD.com
PhD Project - Image-based bacterial phenotyping and antimicrobial drug discovery using smart high-throughput super-resolution microscopy at University of Warwick, listed on FindAPhD.com
www.findaphd.com
February 2, 2026 at 11:11 AM
iCASE PhD project available in my lab, combining microscopy method development with high throughput screening of bacteria. Applications to antibiotic drug discovery and screening for new cell division proteins. Collaboration with Cairn Research #microsky #bioimaging
www.findaphd.com/phds/project...
www.findaphd.com/phds/project...
Reposted by Séamus Holden 🔬🦠🧫
Finally comms from UKRI - on a Sunday evening. No mention of the hundreds of ECRs who will see their careers ended by these decisions and notably no explanation for MRC retrospectively applying cuts and wasting all the work that went into writing, reviewing and scoring applications - £millions
Today, we're sharing an open letter from our Chief Executive, Professor Sir Ian Chapman, outlining changes to UKRI investment approach, and addressing concerns about research funding and the financial position of STFC. Read his letter here: www.ukri.org/news/open-le...
Open letter from Ian Chapman to research and innovation community
UKRI Chief Executive outlines changes to UKRI investment approach, addressing concerns about research funding and the financial position of STFC.
www.ukri.org
February 1, 2026 at 7:21 PM
Finally comms from UKRI - on a Sunday evening. No mention of the hundreds of ECRs who will see their careers ended by these decisions and notably no explanation for MRC retrospectively applying cuts and wasting all the work that went into writing, reviewing and scoring applications - £millions
Reposted by Séamus Holden 🔬🦠🧫
Happy to share a new preprint from the lab: Marko became interested in whether the disordered linker of FtsZ might influence how the protein organizes into the Z-ring. And this led to some surprising findings!
Preprint: www.biorxiv.org/content/10.1...
Preprint: www.biorxiv.org/content/10.1...
Charge segregation in the C-terminal linker of FtsZ enables Z-ring scaling with prokaryotic cell width
Bacterial cytokinesis is orchestrated by the Z-ring, a cytoskeletal structure formed by treadmilling filaments of the tubulin-like GTPase FtsZ. During assembly, filament curvature must match the cell ...
www.biorxiv.org
November 26, 2025 at 9:29 PM
Happy to share a new preprint from the lab: Marko became interested in whether the disordered linker of FtsZ might influence how the protein organizes into the Z-ring. And this led to some surprising findings!
Preprint: www.biorxiv.org/content/10.1...
Preprint: www.biorxiv.org/content/10.1...
Reposted by Séamus Holden 🔬🦠🧫
I’m happy to share the main result of my PhD, which you can find on bioRxiv www.biorxiv.org/content/10.6.... If you are interested in learning about a new way to perform DNA-PAINT multiplexing, which we call Combi-PAINT, or if you are interested in the study of mRNA conformation, keep reading! 1/10
January 26, 2026 at 11:31 AM
I’m happy to share the main result of my PhD, which you can find on bioRxiv www.biorxiv.org/content/10.6.... If you are interested in learning about a new way to perform DNA-PAINT multiplexing, which we call Combi-PAINT, or if you are interested in the study of mRNA conformation, keep reading! 1/10
SAVE THE DATE!
The next instalment of the long-running Bacterial and Archaeal Cell Division Conference will take place at www.marriott.com/en-us/hotels..., Italy from the 20th to 23rd of April 2027.
Organisers: me, @s-lab.bsky.social, @awehenkel.bsky.social.
More info soon.
#MicroSky
The next instalment of the long-running Bacterial and Archaeal Cell Division Conference will take place at www.marriott.com/en-us/hotels..., Italy from the 20th to 23rd of April 2027.
Organisers: me, @s-lab.bsky.social, @awehenkel.bsky.social.
More info soon.
#MicroSky
www.marriott.com
January 26, 2026 at 1:14 PM
SAVE THE DATE!
The next instalment of the long-running Bacterial and Archaeal Cell Division Conference will take place at www.marriott.com/en-us/hotels..., Italy from the 20th to 23rd of April 2027.
Organisers: me, @s-lab.bsky.social, @awehenkel.bsky.social.
More info soon.
#MicroSky
The next instalment of the long-running Bacterial and Archaeal Cell Division Conference will take place at www.marriott.com/en-us/hotels..., Italy from the 20th to 23rd of April 2027.
Organisers: me, @s-lab.bsky.social, @awehenkel.bsky.social.
More info soon.
#MicroSky
Reposted by Séamus Holden 🔬🦠🧫
Our first lab paper is out.
Large-scale testing of antimicrobial lethality at single-cell resolution predicts mycobacterial infection outcomes.
From single cells to patients, across tuberculosis and M. abscessus.
👉 doi.org/10.1038/s415...
👇 Thread
Large-scale testing of antimicrobial lethality at single-cell resolution predicts mycobacterial infection outcomes.
From single cells to patients, across tuberculosis and M. abscessus.
👉 doi.org/10.1038/s415...
👇 Thread
Client Challenge
doi.org
January 12, 2026 at 7:26 AM
Our first lab paper is out.
Large-scale testing of antimicrobial lethality at single-cell resolution predicts mycobacterial infection outcomes.
From single cells to patients, across tuberculosis and M. abscessus.
👉 doi.org/10.1038/s415...
👇 Thread
Large-scale testing of antimicrobial lethality at single-cell resolution predicts mycobacterial infection outcomes.
From single cells to patients, across tuberculosis and M. abscessus.
👉 doi.org/10.1038/s415...
👇 Thread
Reposted by Séamus Holden 🔬🦠🧫
Fabian was quicker :) But yes, we have an open postdoc position in bacterial bioenergetics and membrane biology, using on B. subtilis as the model. Come join us! @cbcb-newcastle.bsky.social is a great place to work, and we are a friendly, international lab. Visa+IHS fees covered. #microsky
January 14, 2026 at 8:56 PM
Fabian was quicker :) But yes, we have an open postdoc position in bacterial bioenergetics and membrane biology, using on B. subtilis as the model. Come join us! @cbcb-newcastle.bsky.social is a great place to work, and we are a friendly, international lab. Visa+IHS fees covered. #microsky
Reposted by Séamus Holden 🔬🦠🧫
🫴 A mechanotransduction mechanism for antibiotic defense in Gram-positive bacteria (Bacillus subtilis, with some interesting suppressor mutants):
In
Structure www.cell.com/structure/fu...
#subtiWiki #subtilis
In
Structure www.cell.com/structure/fu...
#subtiWiki #subtilis
A mechanotransduction mechanism for antibiotic defense in Gram-positive bacteria
In this issue of Structure, Yu et al. show that the Bacillus subtilis ytr operon encodes
two distinct ABC transporters. The authors present the cryo-EM structures of YtrEF
in the apo and ADP-vanadate-...
www.cell.com
January 11, 2026 at 6:55 PM
Reposted by Séamus Holden 🔬🦠🧫
Just 4 days until our Grants, Early Bird & Talk deadline closes for #ProkaryoticCellBio!
Join Heath Murray, Jie Xiao, Marc Bramkamp and Ethan Garner 13 - 16 July 2026 in Portugal, alongside our fantastic speaker line-up!
More info on how to register here➡️https://bit.ly/4qCDhtw
Join Heath Murray, Jie Xiao, Marc Bramkamp and Ethan Garner 13 - 16 July 2026 in Portugal, alongside our fantastic speaker line-up!
More info on how to register here➡️https://bit.ly/4qCDhtw
January 8, 2026 at 11:35 AM
Just 4 days until our Grants, Early Bird & Talk deadline closes for #ProkaryoticCellBio!
Join Heath Murray, Jie Xiao, Marc Bramkamp and Ethan Garner 13 - 16 July 2026 in Portugal, alongside our fantastic speaker line-up!
More info on how to register here➡️https://bit.ly/4qCDhtw
Join Heath Murray, Jie Xiao, Marc Bramkamp and Ethan Garner 13 - 16 July 2026 in Portugal, alongside our fantastic speaker line-up!
More info on how to register here➡️https://bit.ly/4qCDhtw
Reposted by Séamus Holden 🔬🦠🧫
AI folks now having to realise what GWAS folks did about studying bacterial genome datasets. Great work by great researchers
#MachineLearning methods are used to predict #AntimicrobialResistance #AMR from genomic data. @lbarquist.bsky.social &co show that sampling biases driven by population structure severely undermine the accuracy of AMR prediction models even with large datasets @plosbiology.org 🧪 plos.io/4iZ0zXQ
December 17, 2025 at 5:41 PM
AI folks now having to realise what GWAS folks did about studying bacterial genome datasets. Great work by great researchers
Reposted by Séamus Holden 🔬🦠🧫
Want to do great science and beautiful microscopy with a great guy? @maikbischoff.bsky.social is recruiting a PhD student for his new lab!
#cellbio #devbio #microscopy #bioimaging
#cellbio #devbio #microscopy #bioimaging
🚨 PhD Position Available 🚨
I’m recruiting a PhD student to join my lab at the Multiscale Imaging Centre (MIC), Münster, Germany.
www.bischofflab.com/jobs
Fully funded ✅
#Cellbio #Morphogenesis #Microscopy
#Drosophila #PhD
(Details Below)
Original Posting:
stellen.uni-muenster.de/jobposting/d...
I’m recruiting a PhD student to join my lab at the Multiscale Imaging Centre (MIC), Münster, Germany.
www.bischofflab.com/jobs
Fully funded ✅
#Cellbio #Morphogenesis #Microscopy
#Drosophila #PhD
(Details Below)
Original Posting:
stellen.uni-muenster.de/jobposting/d...
December 16, 2025 at 8:52 PM
Want to do great science and beautiful microscopy with a great guy? @maikbischoff.bsky.social is recruiting a PhD student for his new lab!
#cellbio #devbio #microscopy #bioimaging
#cellbio #devbio #microscopy #bioimaging
Reposted by Séamus Holden 🔬🦠🧫
🎓Online-course: Machine Learning for Bio-imaging
📅 9–11 March 2026
🧠 Instructor: @hernanmn.bsky.social
Learn CNNs for image segmentation & classification with hands-on Python sessions on real bioimage data.
www.physalia-courses.org/courses-work...
#Bioimaging #MachineLearning
📅 9–11 March 2026
🧠 Instructor: @hernanmn.bsky.social
Learn CNNs for image segmentation & classification with hands-on Python sessions on real bioimage data.
www.physalia-courses.org/courses-work...
#Bioimaging #MachineLearning
Machine Learning for Bio-imaging
9-11 March 2026
www.physalia-courses.org
December 15, 2025 at 11:04 AM
🎓Online-course: Machine Learning for Bio-imaging
📅 9–11 March 2026
🧠 Instructor: @hernanmn.bsky.social
Learn CNNs for image segmentation & classification with hands-on Python sessions on real bioimage data.
www.physalia-courses.org/courses-work...
#Bioimaging #MachineLearning
📅 9–11 March 2026
🧠 Instructor: @hernanmn.bsky.social
Learn CNNs for image segmentation & classification with hands-on Python sessions on real bioimage data.
www.physalia-courses.org/courses-work...
#Bioimaging #MachineLearning
Reposted by Séamus Holden 🔬🦠🧫
My lab is hiring a postdoc (ERC funded)! If you're interested, get in touch!
December 18, 2025 at 8:36 AM
My lab is hiring a postdoc (ERC funded)! If you're interested, get in touch!
Reposted by Séamus Holden 🔬🦠🧫
We are looking forward to sunnier days and some fantastic presentations at our #ProkaryoticCellBio meeting in Portugal next July! Grants, Early Bird pricing and Talk slots close on 12 Jan, register & submit today to join us! 🌞
👉https://bit.ly/48G29dP
👉https://bit.ly/48G29dP
December 16, 2025 at 3:36 PM
We are looking forward to sunnier days and some fantastic presentations at our #ProkaryoticCellBio meeting in Portugal next July! Grants, Early Bird pricing and Talk slots close on 12 Jan, register & submit today to join us! 🌞
👉https://bit.ly/48G29dP
👉https://bit.ly/48G29dP
Reposted by Séamus Holden 🔬🦠🧫
linguists take note 👇
apart from a few oddities, the similarities and differences between US and UK english correspond quite well to those in sporulation in 𝘉. 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴 and 𝘉. 𝘢𝘯𝘵𝘩𝘳𝘢𝘤𝘪𝘴.
#MicroSky
apart from a few oddities, the similarities and differences between US and UK english correspond quite well to those in sporulation in 𝘉. 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴 and 𝘉. 𝘢𝘯𝘵𝘩𝘳𝘢𝘤𝘪𝘴.
#MicroSky
A new study from the Rudner lab defines a comprehensive set of genes required for spore formation in Bacillus anthracis. Similarities and striking differences between the Bacillus subtilis model and this important human pathogen are described. pubmed.ncbi.nlm.nih.gov/41385520/
December 15, 2025 at 9:14 PM
linguists take note 👇
apart from a few oddities, the similarities and differences between US and UK english correspond quite well to those in sporulation in 𝘉. 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴 and 𝘉. 𝘢𝘯𝘵𝘩𝘳𝘢𝘤𝘪𝘴.
#MicroSky
apart from a few oddities, the similarities and differences between US and UK english correspond quite well to those in sporulation in 𝘉. 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴 and 𝘉. 𝘢𝘯𝘵𝘩𝘳𝘢𝘤𝘪𝘴.
#MicroSky
Reposted by Séamus Holden 🔬🦠🧫
Woop Woop, it's out!!! Congratulations everyone. A beautiful paper
December 15, 2025 at 2:52 PM
Woop Woop, it's out!!! Congratulations everyone. A beautiful paper
@simonecoppola.bsky.social has made micromorph, the first native Python application and library for measuring bacterial morphology. It runs interactively in napari or can be easily integrated into automated Python scripts. It integrates deep learning cell segmentation and is easily extended 🔬🦠🧫
Happy to finally share micromorph with everyone!
If you are interested in performing morphological measurements of bacteria, and like using Python and Napari then this is for you!
You can read about it in our preprint, and find the code on our Github repo, PyPi or directly from the napari hub!
If you are interested in performing morphological measurements of bacteria, and like using Python and Napari then this is for you!
You can read about it in our preprint, and find the code on our Github repo, PyPi or directly from the napari hub!
micromorph: a Python toolkit for measurement of microbial morphology
Detection of morphological phenotypes from light microscopy is a key part of microbiology. Despite advances in automated morphological analysis, accurate measurements still often require significant u...
www.biorxiv.org
December 11, 2025 at 9:19 AM
@simonecoppola.bsky.social has made micromorph, the first native Python application and library for measuring bacterial morphology. It runs interactively in napari or can be easily integrated into automated Python scripts. It integrates deep learning cell segmentation and is easily extended 🔬🦠🧫
Reposted by Séamus Holden 🔬🦠🧫
(𝘌. 𝘤𝘰𝘭𝘪) chromosome replicationists take note 👇 (paper edited by mike o'donnell, so you know where you are)
#MicroSky
#MicroSky
Happy to share our most recent work www.pnas.org/doi/10.1073/.... Here we describe how efficient DNA replication in E. coli is dependent on an interaction between SSB-ssDNA and the DNA polymerase (Pol III). Thanks to all the co-authors for their hard work!
Genome integrity relies on rapid recycling of DNA Pol III in bacteria | PNAS
DNA replication requires precise coordination between DNA unwinding and DNA synthesis.
In all domains of life, protein–protein interactions at the ...
www.pnas.org
November 27, 2025 at 7:13 PM
(𝘌. 𝘤𝘰𝘭𝘪) chromosome replicationists take note 👇 (paper edited by mike o'donnell, so you know where you are)
#MicroSky
#MicroSky
Reposted by Séamus Holden 🔬🦠🧫
wohoo! FtsZ aficionadas/os take note 👇
#MicroSky
#MicroSky
Happy to share a new preprint from the lab: Marko became interested in whether the disordered linker of FtsZ might influence how the protein organizes into the Z-ring. And this led to some surprising findings!
Preprint: www.biorxiv.org/content/10.1...
Preprint: www.biorxiv.org/content/10.1...
Charge segregation in the C-terminal linker of FtsZ enables Z-ring scaling with prokaryotic cell width
Bacterial cytokinesis is orchestrated by the Z-ring, a cytoskeletal structure formed by treadmilling filaments of the tubulin-like GTPase FtsZ. During assembly, filament curvature must match the cell ...
www.biorxiv.org
November 26, 2025 at 10:09 PM
wohoo! FtsZ aficionadas/os take note 👇
#MicroSky
#MicroSky
Reposted by Séamus Holden 🔬🦠🧫
Congratulations @tosinorababa.bsky.social! #MicroSky
🎉 Congratulations to Oluwatosin Orababa @tosinorababa.bsky.social, one of the winners of our 2025 Infection Science Award! 🦠👏
Get to know them in our new interview: microb.io/3XFyCui
#InfectionScience #Microbiology #ResearchSpotlight
Get to know them in our new interview: microb.io/3XFyCui
#InfectionScience #Microbiology #ResearchSpotlight
November 25, 2025 at 12:31 PM
Congratulations @tosinorababa.bsky.social! #MicroSky
New release of the TrackMate single particle tracking plugin for ImageJ by @jytinevez.bsky.social looks amazing! forum.image.sc/t/trackmate-...
Loads of new features, most excitingly to me deep learning segmentation algorithms including Omnipose (for cells), and Spotiflow (for spots) #bioimaging
Loads of new features, most excitingly to me deep learning segmentation algorithms including Omnipose (for cells), and Spotiflow (for spots) #bioimaging
TrackMate v8 - segmentation editor and Python CLI integration
TrackMate v8: 2D Segmentation Editor & Python CLI Integration Hi everyone, I am excited to announce TrackMate v8, a major update introducing key improvements for both end-users and developers. Mai...
forum.image.sc
November 24, 2025 at 2:14 PM
New release of the TrackMate single particle tracking plugin for ImageJ by @jytinevez.bsky.social looks amazing! forum.image.sc/t/trackmate-...
Loads of new features, most excitingly to me deep learning segmentation algorithms including Omnipose (for cells), and Spotiflow (for spots) #bioimaging
Loads of new features, most excitingly to me deep learning segmentation algorithms including Omnipose (for cells), and Spotiflow (for spots) #bioimaging
Reposted by Séamus Holden 🔬🦠🧫
Apply now to attend the next EMBO Bacterial Networks meeting #EMBOBacNet
🗓️13-18 September 2026
📍Sant Feliu de Guixols, Spain
📝Program and registration info: meetings.embo.org/event/26-bac...
👩🔬Organised with co-chair @s-lab.bsky.social and ECR @coralietesseur.bsky.social
#MicroSky
🗓️13-18 September 2026
📍Sant Feliu de Guixols, Spain
📝Program and registration info: meetings.embo.org/event/26-bac...
👩🔬Organised with co-chair @s-lab.bsky.social and ECR @coralietesseur.bsky.social
#MicroSky
November 20, 2025 at 10:16 AM
Apply now to attend the next EMBO Bacterial Networks meeting #EMBOBacNet
🗓️13-18 September 2026
📍Sant Feliu de Guixols, Spain
📝Program and registration info: meetings.embo.org/event/26-bac...
👩🔬Organised with co-chair @s-lab.bsky.social and ECR @coralietesseur.bsky.social
#MicroSky
🗓️13-18 September 2026
📍Sant Feliu de Guixols, Spain
📝Program and registration info: meetings.embo.org/event/26-bac...
👩🔬Organised with co-chair @s-lab.bsky.social and ECR @coralietesseur.bsky.social
#MicroSky
I've made a short blog post summarising currently available substitutes to GeneFrames for bacterial timelapse microscopy.
I will keep it updated with any future developments, so let me know if anything should be added.
holdenlab.github.io/blog/2025/Ge...
#microsky
I will keep it updated with any future developments, so let me know if anything should be added.
holdenlab.github.io/blog/2025/Ge...
#microsky
Alternatives to GeneFrames for bacterial timelapse microscopy | HOLDEN LAB @ WARWICK
Summary of efforts to find alternatives to GeneFrames
holdenlab.github.io
November 19, 2025 at 12:45 PM
I've made a short blog post summarising currently available substitutes to GeneFrames for bacterial timelapse microscopy.
I will keep it updated with any future developments, so let me know if anything should be added.
holdenlab.github.io/blog/2025/Ge...
#microsky
I will keep it updated with any future developments, so let me know if anything should be added.
holdenlab.github.io/blog/2025/Ge...
#microsky