@sultannazir
PhD candidate in Theoretical Biology at Utrecht University Interested in mathematical and computational models of microbial ecology and evolution. Working on MGEs. sultannazir.github.io 🏳️🌈🏳️⚧️🇵🇸✊🏾
➡️ preprint from the lab! Bacteria have loads of antiviral defences in their mobile genetic elements (MGEs). So when MGEs move between bacteria, the defences move with them, generating a fast turnover of defences in bacteria. But what about the antiviral defence turnover in the MGEs themselves? 🤔
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In case you missed it: our review titled "Spatial structure: shaping the ecology and evolution of microbial communities" is out! 🚨
Let me hit you with some highlights on why spatial structure matters. (and why you should care!)
Sharing is appreciated 🙏 🧵👇
doi.org/10.1093/fems...
Most microbes don't live in shaking flasks; spatial structure shapes how microbes interact and evolve at every scale, as we discuss in our recent review @jeroenmeijer.bsky.social @simonvanvliet.bsky.social @bedutilh.bsky.social @bramvandijk.bsky.social and others
academic.oup.com/femsre/artic... 🧵👇
Now officially published in Current Biology 🥳🥳 @mfseidl.bsky.social @binfutrecht.bsky.social
www.cell.com/current-biol...
Welcome to Bluesky, @pieterhart.bsky.social!
Pieter just joined my group as a PhD student studying bacterial genome evolution—exciting years ahead!
Here he is enjoying a chat about his MSc work (w/ @kassipan.bsky.social & @ettema.bsky.social) at Science4Life @utrechtuniversity.bsky.social 🧬🦠✨
🚨#PhD studentship opportunity! Plasmids provide bacteria with antimicrobial resistance, but do they have more fundamental effects on behaviour? 🧫🦠💫🧟♂️
Apply for a 4y funded MRC DiMeN position with me and Jamie Wheeler @livuni-ives.bsky.social www.findaphd.com/phds/project...
Followed by more interesting science about phages by @sultannazir.bsky.social
Excited to present work from my preprint at #SMBI2025 @uni-jena.de on September 18th. I will be speaking on how spatial structure can explain the association of microbial accessory genes with inducible prophages.
asb-conference.hki-jena.de/schedule/
Excited to share new #program, STEPS, which can simulate #dynamics of the E. coli Long-Term Evolution Experiment (#LTEE) or other microbes in serial transfer regime.
telliamedrevisited.wordpress.com/2025/08/12/s...
STEPS developed by @devinmlake.bsky.social, Zachary Matson, Minako Izutsu, and me.
Okay this is what Pride is.
"Around 100,000 march at Budapest Pride in defiance of Hungary’s ban on the event"
The picture brings me incredible joy. So many people. Giant flag. So much joy. So much bravery.
www.pbs.org/newshour/wor...
The first paper of my PhD is now available as a preprint! 🎉
Transposable elements (TEs) don't just jump within fungal genomes, they also move extensively between species. In this study, we screened over 1,300 fungal genomes and found a conservative estimate of 5,500+ horizontal transfer events.
🧩 PhD Position – Origins of Darwinian Inheritance 🧩
This joint PhD project between the @rug.nl (Rampal Etienne & Martijn Egas) and @utrechtuniversity.bsky.social (Bram van Dijk) explores how simple prebiotic systems could evolve reliable information transfer.
Apply here: shorturl.at/WgYMF
Trans women are women.
Trans men are men.
Fuck Harry Potter.
🚨 🧬 Updated preprint on the completed BASEL collection - what's new? Some fun with bacterial immunity and a new P22 relative infecting E. coli K-12. A thread 🧵
Preprint out! Bacteria w/ hyper-replicative filamentous phage lead to overnight emergence of cheater phages. Bacteria w/ both phages can outcompete wildtype, then rapidly lose phage via a phage Tragedy of the Commons
@shellyscrib.bsky.social @vscooper.micropopbio.org www.biorxiv.org/content/10.1...
New online! Interactions and evolutionary relationships among bacterial mobile genetic elements
Inspired by the work of @renskevroomans.bsky.social and @escolizzi.bsky.social on "selfish multicellularity", I made a very different type of model to replicate their results. Take that #replicationcrisis!
(try it yourself here: tbb.bio.uu.nl/bvd/simulati...)
🚨 Now that @sultannazir.bsky.social has written about his work, let me try and summarise what we found. The question we worked on was inspired by Takeuchi et al. (2023) pubmed.ncbi.nlm.nih.gov/37339743/, who illustrated that (pro)phages are enriched in virulence factors compared to plasmids. [1/10]
Illustration depicting the ways in which fungi can exchange genetic material with each other. Starship mediated HGT is confirmed experimentally in this preprint.
We did it! We caught Starship #transposons moving between #fungal species in the lab, including between species separated by ~100my. We think Starships are a mediator of HGT in fungi, akin to conjugative elements in bacteria. Check out the preprint. www.biorxiv.org/content/10.1...
Thanks, Bram! Excited for our next project ✨
Here is the link to the preprint: www.biorxiv.org/content/10.1...
15/15
You can find an interactive version of our individual-based model here: sultannazir.github.io/bacteria_pro...
14/15
By attributing the evolution of gene-phage association to features of the phage lifecycle such as prophage induction regulation and virion dispersal, we help explain what sets apart prophages from other MGEs in terms of the cargo genes they carry.
13/15
Based on these findings, we propose a dispersal hypothesis: Costly gene-phage associations can evolve when phage-mediated dispersal increases the mixing of carrier and non-carrier genotypes, thereby amplifying selection for the gene in a spatially structured population.
12/15
Emergence of host immune response could also weaken the selection pressure acting on virulent mutants. Thus, virulence genes may naturally experience weak selection within the host environment, making them more likely to rely on phage-mediated dispersal more than MGEs with limited dispersal.
11/15
Weak selection is key for non-carrier regions to persist, allowing the benefit of dispersal to take effect.
Most virulence genes are expressed extracellularly, sharing their benefits with other non-carrier cells.
10/15
An illustration depicting the dispersal advantage of a phage-borne gene over a chromosomal gene. As selection acts locally in a spatially structured population, a phage-encoded gene can disperse more and reinforce selection at a higher rate that the mutational more robust chromosomal gene. Under weak selection when more non-carrier genotypes persist, such a dispersal advantage can help the phage-encoded gene globally outcompete the chromosomal gene.
Why? In a structured population, selection acts locally - where carriers meet non-carriers. When the gene is phage-encoded, it can disperse via virions, reaching gene-free regions more effectively. This increases its effective rate of selection compared to the chromosomal gene.
9/15
Result 2: Within-population spatial structure increases the probability of a chromosomal gene evolving to be phage-encoded under two conditions:
1️⃣ Weaker selection pressure
2️⃣ Higher virion diffusion rate
8/15
Since prophage induction is often triggered by environmental factors, this suggests that virulence genes are linked to prophages whose induction rates are higher in the host environment.
7/15
Why? Positive correlation in gene expression & prophage induction between populations connected by migration causes a net influx of non-carrier uninfected cells into the host environment. This creates a selection pressure for the gene to become mobile via prophages.
6/15
