Regensburg 2022 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 10: Cell Adhesion and Multicellular Systems
BP 10.2: Vortrag
Dienstag, 6. September 2022, 10:15–10:30, H13
Blue-light photoreceptors regulating light-switchable adhesion in Chlamydomonas reinhardtii — •Rodrigo Catalan1,2, Antoine Girot1,2, Alexandros Fragkopoulos1,2, Simon Kelterborn3, Darius Rauch3, Peter Hegemann3, and Oliver Bäumchen1,2 — 1Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen , Germany — 2University of Bayreuth, Experimental Physics V, 95447 Bayreuth, Germany — 3Humboldt University Berlin, Institute of Biology, 10115 Berlin, Germany
Photoactive organisms have evolved a variety of light-sensitive molecules, called photoreceptors, which regulate phenotypes such as phototaxis, circadian life cycle and sexual reproduction. Recently it was discovered that the unicellular, eukaryotic microalga Chlamydomonas reinhardtii exhibits light-switchable flagellar adhesion to surfaces [Kreis et al., Nature Physics, 2018]; a phenotype triggered by a blue-light photoreceptor. Using single-cell micropipette force measurements, we show that the action spectrum of flagellar adhesion forces in wild-type (WT) cells resembles the adsorption spectrum of photoreceptors called cryptochromes. Furthermore, adsorption experiments show that the number of WT cells adsorbing to surfaces under blue light increases after the start of the cells’ day-phase, which coincides with the light degradation of plant cryptochrome (pCRY). Adhesion force and adsorption experiments of WT and photoreceptor deletion mutants illuminate the role of photoreceptors in this adhesion phenotype.