Mathieu Preußner

Job alert! 📣 I’m looking for a research assistant to join my new team @idrm.ox.ac.uk

Were using #zebrafish to understand gene-environment interactions that shape the heart 🫀generate natural diversity 🐸🐭 and contribute to congenital defects ❤️‍🩹

Full info below, and please share! 🫶🏻

bit.ly/467TO0M

Christian Helker @unimarburg.bsky.social and co-workers show that apelin signaling acts as a molecular switch between endothelial and hematopoietic #stemcells.

link.springer.com/article/10.1...

Highlight by @labmonteiro.bsky.social @unibirmingham.bsky.social

link.springer.com/article/10.1...

Maximum intensity projection showing dorsal vasculature of the first gill arch of a CUBIC-cleared adult kdrl:mCherry zebrafish. Fluorescent signal was pseudocoloured using the PBIYC lookup table in ImageJ. Analysis of this endothelial reporter enabled detailed mapping of gill vascular development and revealed distinct medial and lateral filament types. Credit text to the journal Development. See Research Article by Preußner et al. https://doi.org/10.1242/dev.204984

Adult zebrafish gill vasculature. Credit to @mathpreu.bsky.social. #ZebrafishZunday 🧪

Wow 😍
Thanks for sharing 🤝

Fig. 1. Animal cap assay and sandwich method as in vitro induction systems. In amphibians, a blastocoel cavity clearly forms inside the animal hemisphere during the blastula and early gastrula stages. The cap-like portion lining the roof of the blastocoel cavity is the animal cap. This region consists of a sheet of pluripotent cells, organized into one or several layers. In the animal cap assay, the animal cap was treated with a physiological saline solution containing inducing factors and then cultured. Depending on the type, concentration, and duration of exposure to the inducing factors, animal caps can differentiate into various cell types. In contrast, the sandwich method, involves culturing the inducer source in between two animal caps. In this technique, the sources of induction can include the dorsal lip of the blastopore (organizer), adult tissues, pelletized soluble factors, or animal caps pretreated with soluble factors. In this figure, activin is used as an example of an inducing factor.

Fig. 12. Summary of the in vitro induction system using activin as an inducing factor. This in vitro induction system utilizes activin and retinoic acid as inducing factors to treat animal caps, employing techniques such as animal cap assay, dissociation/reaggregation protocol, and the sandwich method. By applying these methods, various levels of self-organization can be replicated and controlled in vitro, ranging from lower-order cell differentiation to higher-order tissue differentiation, organogenesis, and even the formation of fundamental body plans. Abbreviations: Dorsal [D], ventral [V], and retinoic acid [RA].

Fig. 11. Formation of embryoids by artificial activin concentration gradients. To create embryoids, animal caps were prepared through treatment with low (0.5–1 ng/ml), intermediate (5–10 ng/ml), or high (50–100 ng/ml) concentrations of activin. These three types of activin-treated animal caps were then sequentially arranged and cultured with untreated animal caps. After 3 days of culture, embryoids with distinct head and trunk-tail structures were formed (A). Histological sections revealed differentiation into head tissues, such as the cement gland [cg] and eyes, and trunk-tail tissues including the ear vesicle [ev], brain [br], notochord [not], muscle [mus], and gut (B). When newt embryos are used in similar combination cultures, neural plate structures forming the brain [white arrow] and axial structures forming the trunk-tail regions [black arrow] are sometimes observed (C).

Fig. 7. In vitro heart formation and in vivo transplantation experiment. When treated with a high concentration of activin, the animal caps of Xenopus embryos did not differentiate into heart tissue. However, if the animal cap dissociates into individual cells before activin treatment and then reaggregates, it forms a beating heart [arrow] with 100 % efficiency (A). This heart expresses differentiation marker genes, such as Nkx2.5, GATA-4, Tbx5, MHCα, TnIc (cardiac troponin I), and ANF, none of which are expressed in an animal cap treated with activin alone, without dissociation/reaggregation (B). Electron microscopy reveals the presence of intercalated discs [id] specific to the cardiac muscle, along with visible mitochondria [m] and Z-bands [z] (C). When the reaggregated heart tissue is orthotopically transplanted into the cardiac primordium of a neurula-stage embryo, it integrates without rejection and continues to beat (D), although it does not persist through host metamorphosis. In contrast, when the reaggregated tissue is ectopically transplanted into the ventral region of the neurula, it begins to beat synchronously with the host heart and gradually reddens as it initiates blood circulation (E).

A fascinating review on the role of Activin in organ induction. Isn't it wild that in Xenopus embryos, a piece of the animal cap can be induced with Activin at different concentrations and buffers to form the ❤️, kidney, the pancreas, head, tail, and even a whole embryoid 🤯:
doi.org/10.1016/j.cd...

This developing quail embryo looks like it's thinking fiery thoughts for #FluorescenceFriday 🐣🔥🧪. Imaged by the fantastic @vanderspuy.bsky.social

Illustration of sword-tailed newt

Illustration of sword-tailed newt #art #wildlife #nature

Illustration of a toucan (Ramphastos Inca) perched on a tree branch with green and brown leaves. The bird features a large, prominently curved yellow and black beak, blue skin around its eyes, a white throat, a red band across its chest, and predominantly black plumage with red and yellow accents near its tail. The background shows a faint, misty forest scene. The style reflects a detailed 19th-century natural history illustration.

🦜 A monograph of the Ramphastidae, or family of toucans
London: Published by the author, 20, Broad Street, Golden Square, [1852]-1854.

[Source]

🚨 The deadline has been extended until January 31st!🚨

We spy a few #zebrafish peeps as invited speakers 🤩

Another pine pollen for #FluorescenceFriday! It seems that this year too, I still won't get tired of colour coding my microscopy 🧡💜💙💚❤️

For #FluorescenceFriday some co-cultured astrocytes 🟢 and neurons 🔴 that ended up looking super cool from the @lieberinstitute.bsky.social Imaging Development group 🔬🤩🧪🧠

Congratulations 🎉

Compact Calm1 promoter enables AAV mediated neuron-targeted expression in human iPSC-derived brain organoids - Scientific Reports Scientific Reports - Compact Calm1 promoter enables AAV mediated neuron-targeted expression in human iPSC-derived brain organoids

New paper out 🔥!

Small promoter, big potential🧬 We show that the ultra-compact Calm1 promoter efficiently targets human neurons in brain organoids and is a promising alternative to hSyn for AAV gene delivery.

Huge thanks to everyone who contributed to this work!
🧠 📄: www.nature.com/articles/s41...

There is still over a week left to apply.
Please send your documents to maik.bischoff@uni-muenster.de

Morphogenesis & Organogenesis!
Part 1 (full) in the comments 👇

Comment if you'd like to be added (regardless of age or career stage!)

Please post your own biology-related starter packs using #BioStarterPacks

🧬🔬🪰🐟🐁🌱

Confocal microscopy image of a juvenile sea star (Patiria miniata) viewed from the oral side. The animal has a five-armed, star-shaped body with a central nerve ring. The nervous system is labeled in green, forming radial nerve cords extending into each arm, and cell nuclei are labeled in red throughout the animal. The image appears against a black background and has a holiday-ornament-like appearance.

Felt a little festive at the microscope this morning for #FluorescenceFriday 🎄

Here’s the nervous system of a juvenile sea star ⭐️

Green = acetylated tubulin, red = nuclei

Happy holidays!

As a biologist working on the cellular and molecular development of gills, I love seeing gill architecture inspire solutions like this plastic-filtering technology....truly inspiring 🦓🐟🔬

🚨 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...

Exciting PhD opportunity in cell migration, developmental biology, and morphogenesis using #Drosophila 🧬

As a bonus, you’ll be joining the lab of one of the nicest, most enthusiastic, and truly supportive scientists out there 👇

Image of cell junction puncta from https://www.molbiolcell.org/doi/full/10.1091/mbc.E23-03-0077

To build the body plan of an animal, cells must adhere to one another via cell-cell junctions. We now know these assemble as punctate protein complexes containing thousands of proteins, but how this occurs remains mysterious. 1/n 🧪
www.molbiolcell.org/doi/full/10....

My team are running the Peripheral Nerve Society's Instagram account this week: www.instagram.com/pnsociety1

If you like images of the nervous system, please check it out!

#FluorescenceFriday
@uclqsneuromuscular.bsky.social
@uclqsion.bsky.social

Unsolicited remix of some cool #FluorescenceFriday images from Matthias Böddener 😁can't go wrong with the Noice LUTS!

A new research facility dedicated to axolotls, will be opening soon. Hosting the UK’s only dedicated axolotl research colony and will support world class studies into regeneration, ageing, cancer resistance and stem cell biology.

edin.ac/4pAAJeW

@edinuni-irr.bsky.social @aidarodrigo.bsky.social

For #FluorescenceFriday - RNAscope marking subfields of the hippocampus in a section of postmortem human 🧠 tissue. Image credit to the Imaging Development team @lieberinstitute.bsky.social 🔬🧪👩‍🔬

Awesome 😍kinda looks like a 🍄 or a 🪼.

This distal gill tip is giving full branchial art vibes for #FluorescenceFriday 🦓🐟
— who knew oxygen exchange could be this pretty.
🔴 kdrl:mCherry highlights the vasculature
⚪ fgf10b:nEOS marks the pillar cells

#Zebrafish #DevBio #SciArt

Your periodic reminder that science is not done by a few selected "stars scientists". Science is done by hundred of thousands. Siloed money mean a few flashy discoveries and a lot of waste. Want to change things? Make funding accessible and stop funding calls with less than 2% success rate.

This… it’s just mind-blowing. Truly incredible insights into gill biology 🐟🔬. Just look at those blood cells moving through the vascular space of the pillar cells. I’m honestly jealous—amazing work! 🎉👏