SKM 2023 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 31: Cell Mechanics III

BP 31.6: Vortrag

Freitag, 31. März 2023, 11:30–11:45, BAR 0106

Geometry sensing by active flows: how the cell cortex can feel its shape — •Jonas Neipel and Frank Jülicher — Max Planck Institute for the Physics of Complex Systems, Dresden, Germany

Morphogenesis often involves chemical patterns, e.g. defined by the concentration of signalling molecules, that specify the shape of a cell or tissue. The robustness of such processes with respect to perturbations can be enhanced by feedbacks where the generated shape impacts back on the formation of the chemical pattern. Here, we show that such shape sensing can result from the same forces that drive shape changes. We consider sheets of active matter, such as the cell cortex or a developing tissue layer, that behave as active fluid surfaces on long time scales. In these systems, forces drive flows within the surface that inevitably depend on the surface geometry of the surface. When molecules are advected by this flow, a pattern arises, reflecting the symmetries of the geometry. In particular, we show that viscous shear forces result in an effective friction force being proportional to the Gaussian curvature, such that patches of contractile stresses are advected towards regions of minimal Gaussian curvature. On a surface with spherical topology but elongated shape, this implies that a contractile ring such as the cytokinetic ring aligns perpendicularly to the long axis of the surface. Hence, the actomyosin cortex can drive alignment of the division axis with the long axis of the cell by a rotation of the entire cell, consistent with recent experiments.