Regensburg 2025 – scientific programme
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BP: Fachverband Biologische Physik
BP 17: Poster Session II
BP 17.29: Poster
Tuesday, March 18, 2025, 18:00–20:30, P4
A flavin-based photoreceptor controls the photoactivation of ciliary adhesion in Chlamydomonas. — •Rodrigo E. Catalan1,2, Antoine Girot1,2, Alexandros Fragkopoulos1,2, Olga Baidukova3, Peter Hegemann3, and Oliver Bäumchen1,2 — 1University of Bayreuth, Experimental Physics V, 95447 Bayreuth, Germany — 2Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany — 3Humboldt University of Berlin, Institute of Biology, 10115 Berlin, Germany.
Light-activated proteins or photoreceptors play a crucial role on the behavior and, ultimately, the survival of photoactive microorganisms. The unicellular biciliated microalga Chlamydomonas reinhardtii has become a model organism to study light-mediated phenotypes, such as photosynthesis and phototaxis, among many others. Recently, we discovered that C. reinhardtii can reversibly switch on and off the adhesiveness of their cilia in blue and red light, respectively [1,2]. We characterized the action spectrum of this phenotype in wild-type (WT) C. reinhardtii cells via single-cell micropipette force measurements, and showed that it resembles the spectral sensitivity of a flavin-based photoreceptor. Further comparison of the ciliary adhesion forces between WT and photoreceptor-targeted mutants reveals that the deletion of two flavin-containing photoreceptors, namely animal- and plant cryptochromes, completely disrupts light-switchable adhesion.
[1] C. T. Kreis et al., Nat. Phys. 14, 45-49 (2018).
[2] R. E. Catalan et al., Soft Matter 19, 306-314 (2023).
Keywords: Cell adhesion; Biological switch; Cilia; Chlamydomonas; Cryptochromes