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BP: Fachverband Biologische Physik

BP 19: Focus session: Physics of cilia: Dynamics of synchronized oscillators

BP 19.7: Vortrag

Mittwoch, 3. April 2019, 16:45–17:00, H11

Light-Switchable Adhesive Functionalities of Eukaryotic Flagella — Christian Titus Kreis, Christine Linne, Marine Le Blay, Anni Röse, and •Oliver Bäumchen — Max Planck Institute for Dynamics and Self-Organization, D-37077 Göttingen, Germany

In contrast to marine phytoplankton, many photoactive microbes live in complex environments, such as liquid-infused soil and moist rocks, where they encounter and colonize a plethora of surfaces. We discovered that the flagella-mediated adhesion of the unicellular, eukaryotic microalga Chlamydomonas to surfaces can be reversibly switched on and off by light [1]. Our in vivo micropipette force spectroscopy (MFS) experiments [2] suggest that light-switchable adhesiveness is a natural functionality of flagella to actively regulate the transition between freely swimming (planktonic) and surface-associated state, which yields an adhesive adaptation of microbes to optimize their photosynthetic efficiency in variable and inhomogeneous light conditions. The kinetics of this transition can be readily probed by MFS experiments, where the cell actively pulls itself towards the substrate (auto-adhesion) until the cell achieves its gliding configuration on the surface. We show that the associated forces are exerted by molecular motors, which are connected to individual flagella-surface contacts. In conclusion, eukaryotic flagella are multifunctional cellular appendages that are not only essential for microbial propulsion but also for cellular adhesion to surfaces.

[1] C.T. Kreis et al., Nature Physics 14, 45-49 (2018).

[2] M. Backholm & O. Bäumchen, Nature Protocols (in press).