Living Systems Institute

Harmansa Group


We are recruiting! PhD project supported by the LSI PhD program (details below). Application deadline 26th November 2025!


Morphomechanics – Shaping Growing Tissues

Morphogenesis describes the generation of biological form during development. It is an inherently mechanical process in which cellular activities such as contractility and growth generate stresses that shape tissues into their characteristic three-dimensional structures. Proper tissue morphology is essential for organ function, and defects in morphogenesis are linked to developmental disorders and disease.

Our research focuses on the mechanical interplay between growing epithelial tissues and their basement membranes (BMs)—specialised sheet-like extracellular matrices that support and constrain epithelia.

Much like the foundation of a building, the BM provides structural support, and its mechanical and growth properties strongly influence tissue shape. We recently showed that differential growth between an epithelium and its BM generates mechanical stresses that guide tissue morphology (Harmansa et.al. 2023). By combining Drosophila genetics, advanced imaging, quantitative biophysical tools, and data-informed modelling, we aim to uncover how such stresses emerge during growth and how they direct the mechanics of morphogenesis.

For more details on our current research, news and open positions please visit our group’s webpage.


News and Recent Publications

  • 10/2025 Check our new review article on the role of growth induced stresses in animal morphogenesis.
  • 09/2024 Our new preprint is online – ‘Mechanical regulation of cuboidal-to-squamous epithelial transition in the Drosophila developing wing’
Diverse cell shapes in the Drosophila wing disc – The large cells of the squamous epithelium (blue) overlay the smaller columnar epithelium (magenta).

Open Positions

We are looking for a PhD student to join our growing research team. The studentship is supported by the LSI PhD program (Apply here). DEADLINE: 26th of November 2025

Forces in the Matrix – Developmental Biophysics Across Species

Co-supervised by Prof. Steffen Scholpp and Dr. David Richards

This PhD project explores how tissues bend and fold during development, focusing on the basement membrane, a thin but rigid layer of proteins that supports and shapes cells. Its main building block, Collagen IV, is essential for healthy growth, and mutations cause a range of human diseases affecting the eyes, kidneys and blood vessels. By comparing two model systems, the fruit fly wing and the zebrafish eye, this project will uncover universal rules of how Collagen IV mechanics sculpt organs, with broad implications for human health and tissue engineering.

More details on the project

Project summary – How do tissues bend, fold and sculpt themselves into functional organs? This central question in developmental biology lies at the heart of morphogenesis, where mechanical forces and extracellular structures work together to shape tissues. The basement membrane (BM) is a specialised extracellular matrix that not only supports epithelia but also actively drives their form. Its major structural component, Collagen IV, builds a crosslinked network essential for stability, growth and signalling. Mutations in Collagen IV compromise BM integrity, leading to developmental defects and human diseases, including eye malformations, kidney disorders and vascular pathologies. Despite this broad relevance, the mechanical role of the BM in shaping organs is still poorly understood.

This PhD project will investigate how Collagen IV organisation and BM dynamics generate mechanical stress and drive morphogenesis across species. Two powerful in vivo models, the Drosophila wing disc and the zebrafish optic cup, provide complementary systems in which epithelial sheets bend into dome-like shapes. Both processes critically rely on BM mechanics, yet the underlying principles remain unclear. Building on our recent discovery that BM growth drives stress accumulation and tissue bending in the fly wing (Harmansa et al., Nat. Commun., 2024), we will test whether similar mechanisms govern vertebrate eye development.

The candidate will combine cutting-edge genetics (CRISPR-Cas9), advanced live and super-resolution imaging, and biophysical techniques (atomic force microscopy, laser ablation, rheology) with theoretical modelling. This interdisciplinary approach will reveal conserved principles of BM-mediated morphogenesis, offering insights with broad
impact on collagen-related diseases and future applications in tissue engineering.

Get in touch with Stefan for more details or to informally discuss the project (s.harmansa@ exeter.ac.uk).


The Morphomechanics group in June 2025 (left to right: Stefan, Jianyi, Anurup & Abhirami)

Want to join our interdisciplinary research group?

Are you excited by the huge diversity of shapes observed in biological systems and how they are generated? Would you like to work in an interdisciplinary environment and bridge between biology, physics and scientific computing? Then come and join our young and dynamic team in beautiful Exeter.
We are always looking for innovative, passionate and motivated undergraduate students, graduate students and postdocs with a strong interested in the biophysical aspects of shape generation during animal development.

In addition to the official openings, we always welcome spontaneous candidatures for internship, master, Ph.D. and postdoc positions. Please get in touch with Stefan if you you would like us to host your own PhD project (e.g. LSI PhD Programme) or postdoctoral fellowship (e.g. Wellcome Early Career Award or HFSP Cross Disciplinary Fellowships).

In general, you can always contact Stefan (s.harmansa@exeter.ac.uk) to inquire about general information and future openings.


Events and Outreach

12th October 2025 – Our group was thrilled to take part in this year’s Futures Event at the Exeter Phoenix, where we hosted an interactive stall celebrating the hidden beauty of flies. We had a fantastic time meeting so many curious and enthusiastic visitors, sharing how these tiny creatures help us understand how living tissues build themselves.
One of the highlights was our hands-on activity “Create Your Own Fly” where children (and quite a few adults!) used colourful play-dough to sculpt their own insects. The creativity on display was amazing, resulting in a whole swarm of wonderfully imaginative, vibrant flies!
A huge thank you to all the young (and not-so-young) artists who joined us — here are a few snapshots capturing the fun and creativity of the day.

Alumni

  • Jessica Jarvis (internship summer 2024)
  • Theodore Natusch (internship summer 2024)