Stoked to present our latest, brilliantly led by Chris et al & Alejandro Torres-Sanchez. How tissues are patterned during development – we found that geometry-constrained ECM fractures pattern the myocardium in the vertebrate heart 1/n

RT @tobyandrews: The heart is a remarkable organ, where form and function arise in parallel – in this case, the heart wall remodels to form….

RT @tobyandrews: Thrilled to see our latest work online @Dev_Cell! 🥳 . How do cells build functional organs with precision?🫀🫁📏 Here, we sh….

Out now! Our very first paper from the lab, an impressive feat by @tobyandrews .where we show how a developing heart grows and scales up its morphological complexity to keep beating. an excellent summary below ⬇️ .

Paper accepted 🥳Many congratulations @tobyandrews! So proud of what you have achieved! Can’t wait to see what you do next. Onwards and upwards from here!

This was a fun exercise. reflecting on my accidental path into science, the questions that drive our lab @TheCrick and thoughts on building a more inclusive scientific community. Grateful for the opportunity.@focalplane_jcs and Subhajit .

RT @preLights: ‘These cracks, they let the developing cells in: A chronicle of trabeculation in the developing zebrafish heart’ 🎵. Theodora….

RT @NCBS_Bangalore: #LatestPublication in @NatureComms by.Dr Raj Ladher & team show that fine-tuned junctional mechanics are vital for alig….

. and If this piqued your interest, we have fully-funded postdoc positions (4+2 years) available! Join the dynamic, collaborative community @TheCrick with access to top-tier technology platforms and an outstanding postdoc training program. Please RT 🙏.

A true team effort brilliantly led by Chris in collaboration with Alejandro, Emily, MC, Toby et al & many others.@TheCrick and friends for discussions/feedback. #zebrafish #HeartMorphogenesis #DevBio Do let us know your feedback/questions 🙏 12/12.

importantly fractures/cracks/defects are not always destructive - biological materials can self-fracture to generate shapes, see Santos-Durán 2025; Dumortier 2019; Duque 2024; Prakash 2021, others . ‘Break To Build’ 🛠️ (stay tuned for more 😎) #BioPhysics #Mechanics 11/n.

Why is all this imp.? Geometry and mechanical deformations are ubiquitous features of developing organs 🫁🫀 – we show that they are not only a consequence of morphogenesis but can also steer the course of morphogenesis! #zebrafish #ECM #HeartMorphogenesis #DevBio #Biophysics 10/.

What happens if we alter tissue geometry? Our model predicted - in a linear heart, strain would be homogeneous, fractures would be linear. We put it to the test—making linear hearts in embryos—and voilà! Homogeneous strain & linear fractures, just like mechanical fractures 9/n

…Are fractures and strain geometry dependent? Yes! As the heart grows, it twists and transforms from a simple tube into a two-chambered pump – maximum strain shifts accordingly, and ECM fractures follow suit—gradually concentrating in the outer curvature of the ventricle…8/n

… but then why do these fractures happen only in the outer curvature? 🤔 …it’s all about the unique geometry of the ventricle! Its shape creates higher mechanical strain in the outer curvature, strong enough to locally fracture the cECM…7/n

How do heart contractions fracture the ECM? Alejandro & Daniel did some cool quantitative biophysical modelling and found that fracturing is mainly driven by how much myocardial tissue stretches! We blocked stretching (but not contraction speed) and saw fewer ECM fractures…6/n

Is the ECM getting mechanically fractured by heart contractions? Yes! Slow it down, speed it up, or block it—fewer, more, or no fractures! And it’s the same in chick hearts 🐣 No heartbeats, no fractures. Is this a conserved process? Maybe 😎😎. 5/n

What fractures ECM – synthesis/degradation? delaminating cells remodel ECM? upstream signalling? – nope! Chris developed a body-explant method to capture live ECM dynamics in beating hearts – found that ECM is initially smooth but gets fractured as the heart starts to beat 4/n

ECM? Can ECM restrict delamination locally? We found local thin ECM areas – fractures – restricted in the outer curvature, running across myocardial tissue, with signatures of mechanical defects. Cells delaminate into fractures, and if we block fractures, no delamination 3/n

As the heart develops, spatially restricted single-cell delamination in the ventricle outer curvature initiate trabeculation, critical for heart function. But why does delamination occur in the outer curvature - prepatterning by signalling? Contrary to the popular theory -No 2/n