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

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.

Fantastic work congrats to you all, it's been great to see this story being build over the years