CPB Annual Meeting 2022

'From molecules to populations'

April 29

29 April | Old Divinity School, St Johns College

Registrationhere

Abstracts (scroll dow)

Poster blurbshere

Programme

13.30 – Registration 

14.00 – Welcome 

14.05 – 15.00 – Keynote Lecture - Jordi Garcia-Ojalvo (Universitat Pompeu Fabra, Barcelona)

"Oscillations as organizers in multicellular populations: from bacteria to humans"

CPB Prizes session

15.00 – 15.20 – Gea van de Kerkhof (Chemistry)

"Structurally coloured bacterial colonies"

15.20- 15.40 – Coffee break + Posters

CPB Prizes session (cont.)

15.40 – 16.00 - Wolfram Pönisch (PDN)

"How cell shapes change during cellular fate transitions"

16.00 – 16.20 - Eva Kreysing (PDN)

"Global membrane tension is independent of polyacrylamide substrate stiffness"

16.20 - 16.40 – Coffee break + Posters

Invited speakers

16.40 – 17.10 - Mekayla Storer (Cambridge Stem Cells Institute)

"Investigating the mechanisms that underlie successful adult mammalian digit tip regeneration"

17.10 – 17.40 - Renske Vroomans (Sainsbury Lab)

"Long-term information integration in the evolution of multicellular development"

17.40 – 17.45 Closing remarks

17.50 - 20.00 - Poster session (+ Prize) and drinks reception

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Abstracts 

Jordi Garcia-Ojalvo - Oscillations as organizers in multicellular populations: from bacteria to humans

Multicellular organisms rely on a careful spatiotemporal orchestration of form and function, covering multiple biological scales that range from molecules to populations. Much current research is being devoted to understanding how space and time are integrated as organisms develop. In this talk I will address this issue in two distant branches of the evolutionary tree, namely bacteria and vertebrates. In both cases, oscillations in time, driven by molecular interactions, are transformed into periodicity in space, driven by cellular behavior. The similarities and differences of this phenomenon between the two types of organisms will be discussed. Group website

Gea van de Kerkhof - Structurally coloured bacterial colonies

Some of the most brilliant colours in nature stem from a mechanism called structural colour. These non-pigmented colours are created by the interaction of light with nanostructures. When light reaches such structures, it creates bright and often iridescent colours through an interference mechanism.

Structural colour occurs everywhere in the kingdoms of life. It is found in animals and plants, such as for example in the brilliantly coloured tail feathers of the peacock. Structural colour also appears in bacterial colonies, where colour is created by the organisation of the cells into highly ordered crystalline structures: photonic crystals. 

Here, we have studied such structurally coloured bacterial strains. We have developed an in-depth understanding of the relation between cell ordering and optical properties of the colony. We then investigated how certain nutrients can affect the appearance of the colony, revealing a metabolic pathway involved in the colouration. Lastly, we have found several new strains of bacteria, from a different taxonomic class than the one where structural colour has been reported thus far. Studying these bacterial colours is interesting in itself, since it is a unique system and there are many unanswered questions about it, but also from the perspective of creating colourful biomaterials

Wolfram Pönisch - How cell shapes change during cellular fate transitions

The development of animals is characterized by a series of cellular fate transitions where cells become increasingly specialized. For many cells, fate transitions are accompanied by shape changes and there are strong indications of coupling between cell shape and fate. Here, we present a pipeline to quantify and analyse cell shapes as cells undergo the epithelial-to-mesenchymal transition (EMT). We then apply our analysis pipeline to investigate the coupling between cell shape and fate during the EMT of MDCK cells. We find that cell morphology is closely associated with their state: While epithelial cells display spherical shapes, mesenchymal cells undergo spreading. After defining the distinct cellular shapes corresponding to cell states, we study how exactly the morphological features of a cell evolve during EMT. To this aim, we investigate cell trajectories of morphological features in a low-dimensional space and describe the evolution of cellular features as a stochastic process. By integrating a morphometric analysis into studies of cell fate transitions, we aim to better understand the crosstalk between cell fate and shape.

Eva Kreysing - Global membrane tension is independent of polyacrylamide substrate stiffness

Dynamic cellular processes such as cell migration and axon pathfinding are regulated by the mechanical properties of the cells’ environment. The mechanosensitive ion channel Piezo1, which is thought to be activated by changes in membrane tension, is a key player in cellular responses to mechanical signals such as tissue stiffness. However, how membrane tension is influenced by substrate stiffness is currently poorly understood. Here, we used optical tweezers to measure effective membrane tension in fibroblasts and neurons as a function of substrate stiffness. To our surprise, global membrane tension was independent of substrate stiffness within the physiological range. However, we found strong differences between membrane tension in cells cultured on compliant substrates and on glass. To explain our observations, we introduce a toy model connecting substrate mechanics, actomyosin contractility and membrane tension. These results provide a deeper understanding of how the complex interplay of membrane and cortical structures influences effective membrane tension and pave the way for a more fundamental understanding of the downstream biological processes.

Mekayla Storer - Investigating the mechanisms that underlie successful adult mammalian digit tip regeneration

The capacity to regenerate complex tissues has largely been lost in mammals in favour of wound healing and scar formation. Remarkably, in some species including mice and humans, the distal portion of the digit tip can regenerate following amputation and involves the formation of a blastema, a transient tissue comprised of progenitor cells responsible for digit tip regeneration. While the blastema is becoming increasingly well understood in amphibians, in mammals, we still know little about the cells or origin of the blastema, or how these cells might differ from cells in the uninjured or non-regenerative digit tips. Here, we show that Pdgfra-expressing mesenchymal cells in uninjured adult murine digits establish the regenerative blastema and are essential for successful regeneration. Single cell profiling demonstrates that the mesenchymal blastema cells are distinct from both uninjured digit and embryonic limb/digit Pdgfra-positive cells. This unique state is environmentally determined, since dermal fibroblasts transplanted into the regenerative, but not non-regenerative, digit will acquire a blastema phenotype and contribute to bone regeneration. Thus, our data support the idea that given an appropriate environment, adult mammalian mesenchymal cells can acquire a precursor-like state and ultimately contribute broadly to mesenchymal tissue repair and regeneration. Group website

Renske Vroomans - Long-term information integration in the evolution of multicellular development

How did the complexity of modern multicellular organisms arise? 

The developmental program decodes genetic information in a fertilised cell through multiple levels of organisation, from the subcellular to tissues of millions of cells to generate a multicellular organism. This program impacts evolution by determining the effect of mutations on the phenotype of the organism by virtue of being the "decoding algorithm". Yet, this program, and all its complexity, is itself shaped through millions of years of evolution. This means that there is an interaction between evolution and development, despite the fact that they occur at such vastly different time scales. I will discuss three examples of this from my own work on computational models of evo-devo questions: on the evolution of animal body axis segmentation; on the evolution of multicellularity; and on the evolution of division of labour. With these, I'll highlight how information integration over long evolutionary time scales may shape the developmental program.Group website

Registration

This event is restricted to members of the University of Cambridge or partner institutions (the Animal Health Trust, Babraham Institute, British Antarctic Survey, Cambridge Crystallographic Data Centre, European Bioinformatics Institute, MRC Laboratory of Molecular Biology, National Institute of Agricultural Botany and the Wellcome Sanger Institute). Please use your institutional email address to register.