See this? This = implanting mouse embryo. Usually this happens inside its mother and is invisible to us, but we can actually watch implantation ex vivo with the hope of understanding why implantation goes awry in embryos of older women. A 🧵...

How do cells navigate up gradients of adhesive proteins?
🤔

Termed "Haptotaxis", this effect is ubiquitous in cell migration, but it's mechanism was poorly understood

We show that passive friction directs cells & explains complex trajectories on gradients

👉 www.nature.com/articles/s41...

🧵1/14 Preprint thread! Can we predict a cell’s fate based on its dynamics? 🔮 Our new study unveils a framework for watching development unfold in real-time, revealing how a cell's shape and movement encode info about its future fate. 🔬📄 Preprint: tinyurl.com/4shf8v4x

Peer pressure shapes the gut: latest publication in @pnas.org by @lepuslapis.bsky.social, @zhaoshh.bsky.social from @mpipks.bsky.social @mpi-cbg.de @csbdresden.bsky.social with colleagues from @flatironinstitute.org and Princeton University. www.mpi-cbg.de/news-outreac...

Now #published @pnas.org: "A model for boundary-driven tissue morphogenesis", a great #biophysics #devbio collaboration led by @danielalber.bsky.social @zhaoshh.bsky.social:

doi.org/10.1073/pnas.2505160122

@mpipks.bsky.social @mpi-cbg.de @csbdresden.bsky.social @flatironinstitute.org

📣 New preprint: Mechanochemical feedback, tissue geometry & rigid-body dynamics initiate rotational migration in Drosophila via spontaneous chiral symmetry breaking. A mechanism generalizable to closed epithelia.
@sreejithsanthosh.bsky.social
biorxiv.org/content/10.1...

BDM is pervasive in development but difficult to understand due to the necessity of incorporating multiple tissue deformations in their global context. We absorb these into simple and measurable parameters and provide both a model and model system to understand boundary-driven morphogenesis. (8/8)

Finally, we follow up the model's predictions by comparing phenotypes in genetic mutants lacking active behaviors by some of the neighboring tissues. We find that without a decrease in enclosed area or movement of the ring off of the posterior pole, it fails to break symmetry. (7/8)

We found that the hindgut deforms in two stages. The first involves uniform dilation and contraction of the rings. The second involves a rapid change in the shape (described by the rapid change in roundness, a shape metric) we explain in the model above. (6/8)

We then acquired a light sheet dataset and tracked each nucleus within the hindgut (~40,000 annotations for one embryo!) as it deformed. We constructed closed space curves, or "contours," that follow the movements of nuclei and mirror the minimal model's representation of the tissue. (5/8)

Using a minimal model, we found that neighbors moving the hindgut onto one side of the embryo and decreasing enclosed apical area is sufficient to drive the break in shape symmetry. The anisotropic curvature of the underlying surface results in the ring-to-keyhole transition. (4/8)

The hindgut itself deforms no less dramatically, quickly breaking shape symmetry and transforming from a circular ring to a triangular keyhole. Does the hindgut deform merely as a result of its neighbors? (3/8)

At the onset of gastrulation, the hindgut primordium is a ring of ~400 cells bordered by canonical examples of actively-deforming tissues such as the germ band (GB), ventral furrow, and posterior midgut (PMG). These neighbors deform either in-plane or out-of-plane. (2/8)

A ring of cells deforms into a triangular keyhole in just 15 minutes. Meet the hindgut, a model for boundary-driven morphogenesis!

Out now in @pnas.org at doi.org/10.1073/pnas... with @zhaoshh.bsky.social, Alex Jacinto, Eric Wieschaus, Stas Shvartsman, @lepuslapis.bsky.social (1/8)

Have you tried a workstation with more RAM and VRAM? We were getting similar issues with files corrupting which were resolved with more memory. Imaris will use more RAM than the raw file size. Unfortunately, no way I know of to salvage the corrupted files.

Now #published in Phys. Rev. Lett. as an Editors' Suggestion: "Mechanics of poking a cyst" - the first paper from the PhD work of @zhaoshh.bsky.social.

journals.aps.org/prl/abstract...

@mpipks.bsky.social @mpi-cbg.de @csbdresden.bsky.social

How many cells do you need to establish PCP? The magic number is 3! Beautiful work by Lena Basta in Danelle Devenport's lab. Happy to have contributed. www.science.org/doi/10.1126/...

How do cells migrate without substrate, e.g. in embryogenesis, when extra-cellular matrix has not yet formed?

Check out our paper in @cp-cellreports.bsky.social on zebrafish lateral mesendoderm migration, led by @stetavano.bsky.social @heisenbergcplab.bsky.social!

www.cell.com/cell-reports...

I am delighted to share with you my first postdoc paper, which has now been published in @currentbiology.bsky.social!
www.cell.com/current-biol...
Thanks to everyone who contributed: A. Chamolly, @aurelienvilledieu.bsky.social, F. Corson and @jeromegros.bsky.

New #preprint: "Euler buckling on curved surfaces" arxiv.org/abs/2503.04303

@zhaoshh.bsky.social and I ask the question that Euler left open: How does an elastic line buckle within a (general) curved surface?

@mpipks.bsky.social @mpi-cbg.de @csbdresden.bsky.social

New #preprint: "A model for boundary-driven tissue morphogenesis" arxiv.org/abs/2503.03688.

A great collaboration with @danielalber.bsky.social @zhaoshh.bsky.social, Alexandre Jacinto, Eric Wieschaus, Stas Shvartsman.

@flatironinstitute.org @mpipks.bsky.social @mpi-cbg.de @csbdresden.bsky.social

Developmental systems have regions that deform actively or passively from their active neighbors. We use a ring of tissue as a model to investigate this boundary-driven morphogenesis in its biological context, learning something about gastrulation and possibly blastopore geometries in the process!

A duo of preprints on the dynamics of the first cell fate decision in mouse by Madeleine Chalifoux (first grad student in the lab!) and Maria Avdeeva (Flatiron).

We use quantitative live imaging of key cell fate determinants to follow the segregation of inner cell mass and trophectoderm lineages.