Fall 2021 Physics Colloquium, Biophysics of pattern formation: Unicellular phototaxis and multicellular self-assembly

Abstract: My lab is interested in biophysical phenomena at the transition from unicellular to multicellular behavior. We combine experiment and theory, and we utilize methods from synthetic biology, systems biology, and biophysics to facilitate the engineering and understanding of such systems. I will talk about two projects: (1) Euglena cells respond to changes in light intensity with intricate polygonal swimming behaviors and light-dark adaptation. This leads to efficient phototaxis strategies and enables to program the collective behavior of many such microswimmers via multimodal light-stimuli. (2) We developed the first synthetic and optogenetic approaches to cell-cell and cell-surface adhesion that enables the self-assembly and patterning of bacterial aggregates (‘Biofilm Lithography’). I will discuss how we can characterize and use these synthetic tools to drive interspecies boundary formation, to implement adhesion-mediated analogs of developmental organizers and morphogen fields, to engineer active mesoscopic bacterial materials, and to study antibiotic resistance in biofilms. Interestingly, we found that a minimal set of four adhesins suffices to program arbitrary tessellation patterns, implying a low critical threshold for the engineering and evolution of complex multicellular systems. ** Refreshments served from 2:45pm – 3:00pm in PAS 218. Thank you.

** https://riedel-kruse.arizona.edu/ [Tsang Nature Physics’18], [Jin PNAS’18], [Glass Cell’18], [Glass Nature Communications’21] Short Bio: Ingmar H. Riedel-Kruse is an Associate Professor at the University of Arizona in the Departments of Molecular and Cellular Biology, Applied Mathematics (by courtesy) and Biomedical Engineering (by courtesy). His research seeks to make it easier to engineer and program multicellular biological systems, circuits and devices in order to foster the human condition. He runs an interdisciplinary lab integrating diverse areas like synthetic biology, biophysics, human-computer interaction design, and embedded cyber-physical systems. He received his Diploma in theoretical solid-state physics at the Technical University Dresden, did his PhD in experimental biophysics at the Max Planck Institute of Molecular Cell Biology and Genetics, followed by a postdoc at the California Institute of Technology. He was then an Assistant Professor for Bioengineering and Biophysics at Stanford University before joining the University of Arizona.