Mathieu Preußner
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mathpreu.bsky.social
Mathieu Preußner
@mathpreu.bsky.social
PhD in the lab of @vlecaudey.bsky.social at JGU. Developmental Biology in #Zebrafish.
Can't believe it — my first‑author paper is out and my image graces the cover of @dev-journal.bsky.social 🎉

Here, we reveal how early developmental programs shape and maintain #zebrafish gill architecture throughout life
🔗 journals.biologists.com/dev/issue/15...

#FluorescenceFriday #LifelongDevSI
October 31, 2025 at 10:55 AM
For this #FluorescenceFriday 🔬
a cryosection of a dissected zebrafish gill, stained with phalloidin (orange) and DAPI (blue-ish).

#Zebrafish #DevBio #Microscopy
October 17, 2025 at 3:15 PM
15🧵
For those who made it this far... 👀
We’re not done with pillar cells.
They’ve got a lot more to say — about mechanics, structure, and dynamics.
More soon in our next paper. Stay tuned! 🧠🧪🔬

AGAIN! Big thanks to everyone involved—especially to
@vlecaudey.bsky.social
September 17, 2025 at 1:59 PM
14🧵
Gills offer a powerful model to study :
🩸 Angiogenesis
💨 Blood flow & pressure
🧠 Neural crest stem cells
🌿 Branching morphogenesis — all in vivo.

Our work provides a detailed framework to explore these complex processes.
September 17, 2025 at 1:59 PM
13🧵
We quantified pillar cell numbers using:
🔬 ECI-based tissue clearing
📏 Isolation of single lamellae from filaments
Then, with the IMARIS Spots Module, we extracted detailed spatial and quantitative data — giving us a precise map of pillar cell distribution.
September 17, 2025 at 1:59 PM
12🧵
Pillar cell number and lamella size showed clear developmental asymmetries — these also depend on:
📍 Whether the filament is medial or lateral
📍 Its position along the dorsoventral axis

This structural asymmetry likely reflects different functional roles of filaments and lamellae.
September 17, 2025 at 1:59 PM
11🧵
But endothelial cells don’t work alone.
Lamellae morphogenesis depends on tight coordination between:
🔴Endothelial cells
⚪Pillar cells (neural crest-derived!)
September 17, 2025 at 1:59 PM
10🧵
Now, lets talk more about lamellae 🍂
We examined the development of gill lamellae.
It all started with an endothelial tip cell from the efferent filamental artery, which migrated across the lamella toward the low oxygen afferent side.

➡️ This forms the outer marginal channel (OMC)
September 17, 2025 at 1:59 PM
Medial filaments were generally longer with more lamellae along most of the dorsoventral axis — except ventrally, where lateral filaments took the lead.

The asymmetry reflects developmental timing: medial filaments form first dorsally, lateral ones ventrally — shaping function well into adulthood.
September 17, 2025 at 1:59 PM
9🧵
This specific early gill developmental pattern sets the stage for adult gill architecture.
We tracked filament and lamella number and distribution across the 4 gill arches between 3.5 and 14.5 dpf up to 6 month.
September 17, 2025 at 1:59 PM
8🧵
But then something unexpected happened (4–5 dpf).
Branching of the medial branchial artery marked a key symmetry-breaking event that separated how filaments formed dorsally vs. ventrally.

👇 In the ventral region (below MBA branch):
🔹 Lateral filaments sprout first
🔹 Medial filaments form later
September 17, 2025 at 1:59 PM
⚪lateral filament formation
September 17, 2025 at 1:59 PM
⚪medial filament formation
September 17, 2025 at 1:59 PM
7🧵
In the dorsal area of the arch, medial filaments emerged first and extended the LBA by connecting to their neighbouring medial filaments. Only after this connection was made, lateral filaments emerged and fused with the LBA.

➡️ We used live imaging to show this formation in action.
September 17, 2025 at 1:59 PM
6🧵
Once the newly established lateral branchial artery (LBA) fused with the branchial artery (BA), the segment of the original BA, located above the fusion site, will be designated as the medial branchial artery (MBA).
September 17, 2025 at 1:59 PM
5🧵
So when do gill filaments form?

Using high resolution live-cell spinning disc microscopy, we mapped their onset.
The first medial filaments appeared around 2.5 dpf. They sprouted from the branchial artery (BA) and began connecting to neighbours — forming the lateral branchial artery (LBA).
September 17, 2025 at 1:59 PM
4🧵
Let’s zoom in 🔍
To study filament morphology in more detail, we used two transgenic markers:
🔴 kdrl:mCherry — marks endothelial vasculature
⚪ fgf10b:nEOS — highlights pillar cell nuclei within the lamellae
Big thanks to @fabianlab.bsky.social for the fgf10b:nEOS line
September 17, 2025 at 1:59 PM
3🧵
Quick primer: Zebrafish have 4 gill arches on each side with filaments. Each filament harbours several stacked lamellae: the site of gas exchange.
Each lamella is encircled by the endothelial outer marginal channel (OMC) and supported by many pillar cells, which maintain the intergrity.
September 17, 2025 at 1:59 PM
2🧵
This curiosity-driven project started by sheer coincidence. While imaging the gills for a different scientific question, I noticed a consistent pattern: filament length varied along the dorsoventral axis.
🔴 Medial filaments (red) were longer than
⚪ Lateral filaments (white) —except ventrally.
September 17, 2025 at 1:59 PM
1🧵
Excited to share my first PhD paper, published in @dev-journal.bsky.social
What if fish gills —often overlook —hold secrets about development, patterning, and function?
We uncovered how early patterning shapes adult gill architecture.
journals.biologists.com/dev/article/...

#DevBio #Zebrafish
September 17, 2025 at 1:59 PM
Big thank you to @biologists.bsky.social, @focalplane.bsky.social and @the-node.bsky.social for sending me the printed poster of my image from their imaging contest earlier this year! 🔬
It finally found a spot in my new flat — I couldn’t be happier to have this piece of science art on my wall❤️💙
September 5, 2025 at 2:17 PM
2/2
Also got a close-up where the expression pattern goes full-on pointillism

Among others, fgf10b is expressed in gill pillar cells, that structure the vascular network within the lamella.
July 11, 2025 at 12:45 PM
1/2
🧬🎨 When gills do Pointillism!

For this #FluorescenceFriday,
here’s a dissected gill arch expressing nuclear fgf10b:nEOS — depth color-coded: blue for medial filaments, yellow for lateral ones.

#Zebrafish #DevBio #Microscopy #Gills
July 11, 2025 at 12:45 PM
It’s a quill? A sea pen? No—it’s a gill filament! 🪶🪸🐟

Under the microscope, this fish gill structure looks just like a sea pen.
Fascinating how nature keeps circling back to the same shapes.

Want to learn how gills develop?
👉 www.biorxiv.org/content/10.1...

#FluorescenceFriday #Zebrafish
June 20, 2025 at 1:30 PM
9)
Gills offer a powerful model to study angiogenesis, blood pressure, (NC) stem cells, and branching morphogenesis in vivo. Our work provides a detailed framework to explore these complex processes. We anticipate this resource will serve as a foundation for future functional & mechanistic studies
June 6, 2025 at 4:12 PM