Toby Andrews

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

A disrupted compartment boundary underlies abnormal cardiac patterning and congenital heart defects - Nature Cardiovascular Research Kathiriya et al. identify a cardiac progenitor lineage with expression of Tbx5 and anterior heart field-specific expression of Mef2c that bisects the intraventricular septum during development and sho...

Helping this mood is our latest now out in its final form! @irfankathiriya.bsky.social leading the teams with me. Thanks to the editors and reviewers (incl. @wythelab.bsky.social)for a pleasant and productive journey. More to come when the full issue is out. www.nature.com/articles/s44...

Today in Oxford - the Jenkinson DevBio symposium, showcasing exciting #DevBio science from all around the UK! What a lineup 🎉

@vmetzis.bsky.social @tobyandrews.bsky.social @simoesfilipa.bsky.social @jvermot.bsky.social

@idrm.ox.ac.uk

How the functional architecture of the zebrafish heart is shaped during development

📹 @tobyandrews.bsky.social et al @rashmi-priya.bsky.social
lab @crick.ac.uk in @cellpress.bsky.social Developmental Cell

➡️ bpod.org.uk/archive/2025...

Now published in @natcomms.nature.com! 🥳

👉 rdcu.be/eATn3

We developed image analysis tools to capture the nematic orientation field of 3D tissue surfaces. Tested on epithelial aggregates, zebrafish hearts, myoblasts on spheres & micro-vessels, we combined soft matter physics with exp. biology.

Start-Shape-Stop: Cell communication mechanisms controlling organ size Accurate growth control is critical for the achievement of proportional organs during animal development and repair processes. Either extra or deficie…

Hot off the press!!! Proudly presenting our lab's new review on how do cells communicate to control organ size :) We focus specially on dynamic connections that operate at different timescales to regulate organ growth and morphogenesis. #devbio #SizeandShape www.sciencedirect.com/science/arti...

Heartiest congratulations and thanks to @rashmi-priya.bsky.social on the first of many studies from the lab, and for supporting me through its morphogenesis from start to finish 🫀

A huge thanks to all authors for their work in bringing this project to life @jcornwallscoones.bsky.social @mcramel.bsky.social @kirtigupta.bsky.social @jamesbriscoe.bsky.social and our colleagues and facilities @crick.ac.uk 13/n

Looking forward - a deeper understanding of these design principles will give us better insight into what makes development robust, and how it can be steered to produce diversity, novelty, and disease 12/n

Together, we learn that the shape and size of the heart aren’t hardwired, instead they’re worked out through a flow of information across scales, giving rise to self-organising and emergent features 👀 11/n

Not only this, they were also more functionally efficient, owing to a greater blood filling capacity. 10/n

To test the model, we came up with a neat genetic approach to disrupt actin turnover in the Notch+ population. Following the model predictions, when activated at sufficient density, this made hearts bigger... 9/n

To understand how coherent changes in organ shape and size could arise from stochastic signalling @jcornwallscoones.bsky.social developed a 3D vertex model, which predicted the ventricle should grow suddenly, when enough cells soften 8/n

Looking more closely, we found intrinsic changes in actomyosin tension enable stretched cells to change shape in response to organ scale forces. This is a local response to Notch, activated in a stochastic pattern 7/n

Using drugs to disrupt the heartbeat, we found cells stretch in response to the force of ventricle contraction. This also traps them in the compact layer, meaning trabecular density stabilises at a threshold of force production 6/n

meanwhile, by unwrapping the heart, we found that compact layer cells stretch. This allows the heart to grow in size despite losing cells from its outer layer 5/n

Using single cell tracking, we found trabecular cells don’t just divide to form ridges. Instead, they recruit cells from the surrounding compact layer... 4/n

As the embryo grows, the heart expands in size and forms two layers – an elastic compact layer, and an inner layer of muscular trabecular ridges that help to power heart contraction 3/n

The heart is a remarkable organ, where form and function arise in parallel – in this case, the heart wall remodels to form a complex architecture, while the heart beats to support blood flow to the peripheral organs 2/n

Mechanochemical coupling of cell shape and organ function optimizes heart size and contractile efficiency in zebrafish Andrews et al. demonstrate that multiscale feedback between mechanical and chemical cues builds a functional heart to support zebrafish embryonic life. Cell recruitment and organ-scale forces drive tr...

Thrilled to bits to see our latest work online in Dev Cell! 🥳

We wanted to know how cells build functional organs with precision🫀🫁📏 Here we show how coupling of cell shape and organ function fine tunes the form and contractile power of the developing #zebrafish heart 1/n

tinyurl.com/cell-stretch

CT scan of the head clasper (tenaculum) from the Spotted Ratfish (Hydrolagus colliei), compete with its rows of shark-like teeth!

Our paper features fossil reconstruction art (of Helodus simplex) by Ray Troll - https://www.trollart.com/

New Pre-Print Alert! "Teeth Outside the Jaw: Evolution and Development of the Toothed Head Clasper in Chimaeras." We use fossil evidence, development and CT scans through ghost shark ontogeny to describe the emergence of the tenaculum! 👻🦈🦷 @karlycohen.bsky.social
www.biorxiv.org/content/10.1...

Latest work:

Review on the evolvability of vertebral number, and the developmental processes underpinning it

Written by Callum Bucklow, @bertaverd.bsky.social, and myself

Check it out here: doi.org/10.32942/X2K...

A fantastic opportunity to take on evolution with experimental embryology

Great lab, mentor, department, and model system 🐠 don't miss out!

🚨📢 New paper alert! Our work showing that bilateral cellular flows display asymmetry prior to left–right organizer formation in amniote gastrulation is now published in PNAS!! @pnas.org
🥳😃 🐣
Paper link: www.pnas.org/doi/10.1073/...

News article: news.miami.edu/stories/2025...

An ancient patterning system co-opted to position the chordate forebrain 🧠

Amphioxus spilling more evolutionary secrets - beautiful and rigorous work from @giacomogattoni.bsky.social (but no surprises there!)

Registration and abstract submission for YEN 2025 is officially open!

We are looking forward to seeing you at the 17th Young Embryologist Network Conference on the 19th May 2025.

Attendence is FREE thanks to our amazing sponsors: @biologists.bsky.social @10xgenomics.bsky.social and Azenta.

Maximum intensity projection of a live embryonic zebrafish heart at 72 hours post fertilisation, showing myocardial actin (green; Tg(myl7:LifeActGFP)) and endothelial actin (magenta; Tg(fli1a:Ac-TagRFP)). The image is overlaid in the atrium with 3D reconstructions of the myocardial (light blue), endocardial (pink) and extracellular matrix (orange), and in the ventricle with a 3D reconstruction of the myocardium colour-coded to visualise myocardial thickness.

Tools to analyse early heart morphogenesis in detail are limited. @noelresearchlab.bsky.social &co develop computational package called morphoHeart that allows for integrated 3D analysis of both #heart & extracellular matrix morphology in live #zebrafish embryos 🧪 @plosbiology.org plos.io/42DlqtJ

Spheroids are simple systems with only convex curvature. What about more complex systems?

We teamed up with @tobyandrews.bsky.social & @rashmi-priya.bsky.social, and analyzed the ventricular myocardium of Zebrafish hearts ... and it works! 👇

(Directors: high alignment = red, misaligned = blue)

How can we accurately measure features on curved 3D tissues? 📐

Normally we rely on lossy 2D projections, but @juliaeckert.bsky.social's new method detects nematic orientation fields on surfaces of arbitrary geometry

We tested it in hearts, and works a charm! 🫀 More in Julia's thread below 👇🏻

Andrews, T. G. R., & Priya, R. (2024). The Mechanics of Building Functional Organs. Cold Spring Harbor perspectives in biology, a041520. Advance online publication. #EpithelialMechanicsReview
https://cshperspectives.cshlp.org/content/early/2024/06/15/cshperspect.a041520.abstract