School of Physics Colloquium

Speaker: Kirsty Wan (Exeter AC UK)

Host: Prof. Dan Goldman

Title: From sea cells to sea shells

Abstract: At the microscopic scale, virtually everything moves. From diverse patterns of movement one can distinguish living from non-living matter, bacteria from eukaryotes, random from directed, purposeful movement. I will discuss our recent work on phenotyping the motility of diverse microeukaryotes from long-time trajectory statistics. These include microswimmers that orchestrate propulsion-generating appendages (cilia and flagella) for swimming through fluids, as well as organisms that glide mysteriously without the need to resort to any appendages at all. We derive species-agnostic measures of active motility from high-speed live imaging experiments. We show how to distinguish between distinct yet stereotyped states (or gaits) of activity, and demonstrate how environmental cues (e.g. physical confinement, light, chemicals) induce systems-level cellular signalling whose effect becomes measurable in terms of transition probabilities between states. Finally, we speculate on the implications of these findings for the evolution of cellular decision making in basal eukaryotes.

Bio: Kirsty Y. Wan is associate professor at the Living Systems Institute, University of Exeter, UK, where she heads an interdisciplinary group researching the biophysics of microscale navigation, with particular emphasis on the motility and coordination of cilia. She obtained her PhD in biological physics from the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, where she also held a Thomas Nevile Junior Research Fellowship at Magdalene College (2014–2017). In 2020, she received an ERC Starting Grant to explore the origins of motility and cognition in diverse protists.