It is a huge pleasure to nominate Professor Helen Skaer for the BSDB Waddington medal. She is a tireless advocate for our community, and has been teaching, inspiring and supporting developmental biologists for over 50 years. Throughout her career, Helen has been fascinated with understanding how cells are organised/organise themselves to produce physiologically functional organs. Her work unravelling the coordination between diverse cellular behaviours such as cell division, specification, differentiation and migration during morphogenesis has made major contributions to our understanding of organogenesis. Given her outstanding research, inspirational teaching, and her wide regard in the community, we believe she embodies the values the Waddington Medal aims to promote. We are confident that she will give a phenomenal Waddington lecture, that will serve to inspire the whole community.

Helen was one of the very first developmental biologists to tackle the relationship between form and function. During her PhD, Helen focused on understanding how excitable cells are resilient to environmental fluctuations in osmotic and ionic potential, giving her a grounding in cellular physiology. She then moved her focus to epithelial tissues – initially probing the relationship between their structure and their specific physiological attributes. During this phase of her work, she demonstrated that in invertebrates, which lack tight junctions, septate junctions can restrict paracellular flow and so contribute to epithelial tightness. She also pioneered technical developments in the low temperature preservation of material for freeze-fracture, leading to the vitrification of biological samples for electron microscopy.

Through this work, Helen became interested in the cellular activities that underlie the development of epithelial tissues; she set out to understand how intrinsic patterns of gene expression integrate with external signals to define specific cell behaviours. She decided to use the Malpighian (renal) tubules of Drosophila as a model tissue – realising that this system would enable her to combine cellular, genetic and molecular approaches with definable physiological readouts. This choice proved inspired: over the years she has dissected out the distinct cellular and molecular behaviours underlying the development of an epithelial tissue into a physiologically functional organ – pioneering ‘multi-scale’ developmental cell biology long before it became trendy!

Helen’s innovation and determination shine through in both her research and teaching successes. A standout example is from the late 80’s, when Helen demonstrated that the large cells at the tip of the developing renal tubules are mitogenically active, by dissecting open Drosophila embryos and ablating these single cells manually. As students, we loved to hear about Helen ablating renal tubule tip cells by sucking them up finely pulled capillary tubes – it inspired us to think outside the box and believe that anything was possible if you put your mind to it. Using genetic approaches, she then demonstrated that these cells are selected in the tubules by a combination of intrinsic factors and intercellular signalling; through the activity of the proneural transcription factors, whose patterns of expression are regulated by Wnt signalling and by Delta/Notch-mediated lateral inhibition. This was one of the early demonstrations that specific cell lineages outside the nervous system are specified by the refinement of proneural gene expression by lateral inhibition.

Over the years, the work of Helen and her lab has shed light on the regulation of features common to the architecture and function of all epithelia. Many of their findings have contributed to our understanding of vertebrate organogenesis, through their demonstration of conservation in regulatory pathways and networks, in their roles during nephrogenesis and more broadly in the development of tubular epithelia.

Helen has always combined research with an impressive range of teaching and outreach activities. Teaching undergraduate courses in Cambridge, Oxford and Sheffield continuously since 1968, Helen designed and ran courses in developmental biology at all three institutions, including the first interdepartmental course in Oxford across the Biological Sciences/Medicine departments. She has trained over 50 summer vacation and final year students in her lab, many of whom have gone on to do PhDs and some of whom are now University academics teaching developmental/cell biology themselves (e.g. Tanya Whitfield, Keith Brennan, Peter Baumann). Finally, Helen plays a key role in promoting developmental biology in India, giving many talks to college students, and participating in both formal and informal collaborations in the NCBS in Bangalore. She has been a panel member for the India Alliance since its inception – a collaboration between the WT and Indian Department of Biotechnology, supporting and advising scientists across the community.

• Nicolas Tapon
• Kyra Campbell
• Tanya Whitfield
• David Strutt
• Marysia Placzek

I am writing to enthusiastically support Rory Maizels’s nomination for the Beddington Medal. His PhD work represents a remarkable achievement that advances our field’s long-standing goal: developing dynamical models that capture the full complexity of developmental systems. The central challenge in developmental biology is to understand how complex, multicellular tissues emerge from the coordinated actions of individual cells. While we have made great strides in identifying key molecular players and mapping gene regulatory networks, we still lack the ability to create predictive dynamical models that capture development in its full complexity. Rory’s work represents a critical step toward addressing this fundamental challenge. What sets Rory’s contribution apart is both its comprehensive scope and meticulous execution. Rather than pursuing flashy but superficial advances, he focused on building robust foundations – developing and rigorously validating new experimental and computational approaches that together enable dynamic modelling of development at scale. Remarkably, Rory personally drove every aspect of the project: from optimising molecular biology protocols and establishing automated laboratory workflows, to designing novel machine learning frameworks for analysing the resulting data. This rare combination of experimental and computational expertise allowed him to iterate between theory and practice in a uniquely effective way.

Prior to his PhD, Rory built a strong foundation through diverse research experience: molecular biology at LMCB UCL, developing computational tools for mitochondrial research at Oxford (resulting in an eLife publication), and completing the prestigious Frank Knox Fellowship at Harvard in Computational Science and Engineering. It is important to emphasise that this fellowship was not simply a bioinformatics MSc but a computational course aimed at engineers and data scientists. This unique background prepared him perfectly for tackling the emerging challenges in single-cell genomics and developmental biology. At the Crick, he quickly demonstrated exceptional independence and scientific maturity, showing deep knowledge of the field while working autonomously and effectively communicating complex ideas to others.

In the first months in the lab (during the COVID pandemic), Rory led the computational analysis of a major single-cell RNA sequencing study of human neural development, analysing data from multiple stages of embryonic spinal cord tissue to identify distinct cell types and map differentiation pathways. His analysis not only revealed the diversity of neural cell types and their developmental trajectories but also provided important comparative insights between human and mouse development, demonstrating both his technical capabilities and his ability to collaborate effectively on complex projects. This work is published.

In his main PhD project, Rory developed novel experimental and computational methods. This delivered three major technical innovations that together advance our ability to study developmental dynamics. First, he developed sci-FATE2, an optimized and semi-automated protocol for metabolic labelling and single-cell RNA sequencing that matches commercial platforms in quality while being simpler to implement. This is published as a methods paper. Second, he created Velvet, a deep learning framework that improves upon existing methods for inferring cell state transitions from RNA data by integrating neighbourhood information into its velocity calculations. Finally, he extended this work with VelvetSDE, a cutting-edge neural stochastic differential equation system that can predict long-term cell fate trajectories and identify key decision points in development, while capturing the inherent variability in cellular decision-making. Applying this to data from the neural tube led to the realisation that expression of Shh modulators are crucial for differential signal interpretation and cell fate decision in the developing neural tube. This combination of experimental and computational advances provides a robust framework for studying the complex dynamics of development at unprecedented scale and resolution. The work recasts single-cell analyses from descriptions of observed data to models of the dynamics that generated them, providing a framework for investigating developmental fate decisions. This work is published.

Rory’s unique combination of creativity, determination, and technical expertise is responsible for the success of the project. His exceptional strengths in both experimental and computational approaches, spanning molecular biology to machine learning, gives him an ability to tackle complex biological problems from multiple angles. But his ability is not limited to technical skills. He is a deep thinker and has developed a clear and far-reaching view of the future of developmental biology. These scholarly capabilities are evidenced by his invited review on single-cell transcriptomics, which he authored independently following a well-received presentation at the Royal Society. We are also completing an article that sets out a vision for developmental biology in the single cell genomics era. In short, Rory is both a thinker and a doer.

The impact of Rory’s work is already evident in the catalytic effect it is having in the field. It has attracted substantial funding (three grants: CRUK Development, Crick I2I Funding, BBSRC project grant) and underpins five new projects in the lab, including single-cell screening of glioma transcription factors, timeresolved sequencing of organoids, and targeted sequencing approaches. Beyond our group, it has enabled new collaborations in cancer screening, neurodegeneration research, and immunology with leading labs. Most notably, this work formed the foundation for Rory’s successful fellowship application for post-doc at EBI and Sanger, where he will further develop these approaches.

Rory exemplifies the qualities we hope to cultivate in our field: deep theoretical understanding combined with practical capability, rigorous methodology alongside creative vision, and the ability to both conceive and execute transformative research. He is not just technically accomplished but a profound thinker about the future of developmental biology and a clear communicator. His work demonstrates both the insight to identify fundamental challenges and the skill to address them systematically.

Given the extraordinary breadth and depth of his contributions, his proven ability to execute complex interdisciplinary projects, and the clear impact his work is already having on the field, I believe Rory Maizels is an outstanding recipient of the Beddington Medal. He represents the kind of scientist who will help lead our field into its next phase, where we can finally begin to build a comprehensive understanding of development.

James Briscoe