Alexandre Mayran

En tant que chercheur 👨‍🔬, je peux témoigner que la précarité administrative manufacturée par le racisme ambiant freine le travail de brillants 🌟 chercheurs étrangers qui nous font l'honneur de venir travailler en France 🇫🇷.

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

🧬🔬🪰🐟🐁🌱

Using fluorescence live imaging and an in vitro implantation model, we show that human embryo attachment begins with direct cell fusion via syncytin-2–MFSD2A interaction.
With @hansclevers.bsky.social.
Great work by @tnoordzij.bsky.social & @martinacelotti.bsky.social
www.biorxiv.org/content/10.6...

A human embryo implantation model from the @Rugg-Gunn Lab

*key for understanding the early extraembryonic-maternal interactions

Congrats to everyone involved! It’s been great to see this project develop. Huge credit to the @babrahaminst.bsky.social authors 🥂🍾

www.cell.com/cell/fulltex...

Would love to be added to the list too. Thanks for making this starter pack.

Modeling human embryo implantation in vitro Building an in vitro model of receptive endometrium allows investigation of human embryo implantation and early post-implantation development and recapitulates the earliest stages in establishing the ...

Christmas has come early. Fantastic to see this beautiful study from Peter Rugg-Gunn's lab at The Babraham Institute published today. Congratulations to Matteo Mole, Sarah Elderkin, Irene Zorzan and all other authors!
www.cell.com/cell/fulltex...

I'd love to be added please

Modelling co-development between the somites and neural tube in human trunk-like structures - Nature Cell Biology Makwana, Tilley et al. generate human stem cell-based trunk-like structures approximating Carnegie stage 13–14 of development. They use them to model and study the development of the thoracic and lumbar trunk.

Lovely little pre-Christmas present to see this out @natcellbio.nature.com! Some 🔥 new results in here since the biorvix incl (1) a new RARE-GFP reporter ✳️🙌, (2) additional NMP quantification 🔢, (3) no neural tube patterning on RA inhibition 🙅 etc. Enjoy! 😍 www.nature.com/articles/s41...

Specialized signaling centers direct cell fate and spatial organization in a mesodermal organoid model Stem cell–derived mesodermal organoids reveal how signaling centers guide cell fate and tissue organization.

🎉 Our deconstructed, stem-cell–based approach to studying signaling centers and limb-development cell types is out! 🥳 So nice to see it in its final form after the preprint— and huge thanks to the community for all the enthusiasm and interest since then!
www.science.org/doi/10.1126/...

It's always special when you find your own paper in the table of contents of the journal 😍

"The cis-regulatory logic integrating spatial and temporal patterning in the vertebrate neural tube" -> Now out in its final form

www.cell.com/developmenta...

Thrilled to share our new review in Current Opinion in Genetics & Development on TE driven innovation in gene regulation🤘. I am honored to be part of this with two major TE aficionados @cedricfeschotte.bsky.social and @trono-lab.bsky.social
#TEsky #TEworldwide

authors.elsevier.com/c/1m6MC,LqAZ...

Stay tuned for other announcements to come soon @institutcochin.bsky.social 12/12

Major thanks to all the funding agencies, @snf-fns.ch , #NRP79, EPFL, @hfspo.bsky.social , and to the three reviewers for their constructive comments helping improve the manuscript. 11/12

Finally, a big thank for all co-authors: Dominique Kolly, Lucille Lopez Delisle, @yuliia-romaniuk.bsky.social, @maxineleonardi.bsky.social , Anne Catherin Cossy, Theo Lacroix, @hocinerekaik.bsky.social , Ana Rita Amândio, @pierreosteil.bsky.social , and @denisduboule.bsky.social. 10/12

Our data supports that the interaction of somitic cells with N-Cadherin mutant cells of the same identity can be sufficient to drive epithelialization, bypassing both Matrigel in vitro or Surface ectoderm ex vivo requirement. 9/12

Interestingly, this is reminiscent of a study in 2000, where Correia and Conlon reported (www.sciencedirect.com/science/arti...) that tail bud explants only form epithelial somite when both mesoderm and surface ectoderm are present. 8/12

Surprisingly, we found that WT cells in the anterior portion establish an apico-basal polarity, with the basal side facing N-Cadherin mutant cells similarly to what Matrigel would normally cause. 7/12

This coherent organization even leads to the formation of polarized somitic tissue, despite the WT cells normally requiring Matrigel for this. 6/12

How are these organized? N-Cadherin expressing cells are dispersed along the entire A-P axis forming a network of connected cells. However, tissue organization is much more coherent, suggesting that cell fate organization can dominate over N-Cadherin expression. 5/12

We generated mosaic gastruloids with varying proportion of mutant cells to force differential N-Cadherin expression. Interestingly, the elongation was directly correlated to the proportion of mutant cells, linking gastruloid elongation to cell adhesion. 4/12

However, unlike TLS which rely on Matrigel, this occurs without any epithelialization. 3/12

Here, we could confirm that gastruloids lacking N-Cadherin self-organize correctly, in fact even better than their wildtype counter part as they form polarized somitic tissue without requiring exogeneous extra cellular matrix such as matrigel. 2/12

Cadherins modulate the self-organizing potential of pseudo-embryos Gastruloids derived from ES cells mimic embryonic patterning through robust self-organization. Mayran et al. uncover that this competence depends on a cadherin switch regulated by Snai1-driven E-cadhe...

Happy to present the final version of our Cadherin and gastruloid manuscript, online at @cp-cellreports.bsky.social.
www.cell.com/cell-reports...
Initially in BiorXiv (www.biorxiv.org/content/10.1...) 1/12

And we have another open position, this time with a focus on Genome Biology! Join a great community in Vienna to bring your research to the next level!

Spread the word! There is a professor position opening at our University @upcite.bsky.social. There are several possible (great) labs to join, but if you are interested in DNA methylation and epigenetics in mammals, don't hesitate to contact me directly!

Really excited to present the results of a fantastic collaboration with Jesse Veenvliet @jesseveenvliet.bsky.social @mpi-cbg.de @poldresden.bsky.social 🤩

We find a unique mechanism for body axis elongation in mammals, different from other vertebrate species

➡️ www.biorxiv.org/content/10.1...

thanks for sharing this tool. I was all the more impressed that I also gave it 'non' biological papers : it found very technical gaps. It also scans and interprets the figures, and all of this is done very quickly. I honestly think this approach is going to revolutionize our way to deal with papers.

Dissecting the impact of transcription factor dose on cell reprogramming heterogeneity using scTF-seq - Nature Genetics This study introduces single-cell transcription factor (TF) sequencing, a single-cell barcoded and doxycycline-inducible TF overexpression approach that reveals dose-sensitive functional classes of TFs and cellular heterogeneity by mapping TF dose-dependent transcriptomic changes during the reprogramming of mouse embryonic multipotent stromal cells.

🧵1/ Excited to share our new paper introducing a new #singlecell assay: scTF-seq, a high-throughput single-cell approach to explore how transcription factor (TF) dose shapes cell identity and reprogramming outcomes. 🔗 www.nature.com/articles/s41... Big congrats to the entire team @EPFL & @SIAT_China

In this beautiful system, we could show uncoupling of gene expression profiles, morphology and patterning… #NotInTheGenes 😉 (also includes a method to do long term 🔬 of elongating gastruloids)
Thank you to all involved @jeromewongng.bsky.social @thomasgregor.bsky.social @alexandremayran.bsky.social