Karsten Kruse

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Morphogenesis—the generation of biological form—is a central aspect of tissue development and regeneration. From a physical perspective, many tissues can be described as active fluids exhibiting macroscopic orientational order. Here, activity refers to the local conversion of chemical energy into mechanical work, while orientational order characterizes the alignment of cells. The study of such active materials has provided key insights into morphogenetic processes. A prominent example is the emergence of spontaneous cell flows, observed at various stages of development and naturally arising in polar active fluids. However, the mechanisms that organize these flows remain poorly understood. Recent work suggests that topological defects in the orientational order of tissues play a crucial role in this context. These defects have also been implicated in the buckling of epithelial sheets and in driving three-dimensional tissue deformations. In this talk, I will introduce the concept of topological defects in active matter and illustrate, through specific examples, how they can organize flows and contribute to morphogenesis.

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Biochemistry Department, University of Geneva
H3
Contact: Tobias Bollenbach