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DY: Fachverband Dynamik und Statistische Physik

DY 15: Active Matter II (joint session BP/CPP/DY)

DY 15.3: Talk

Tuesday, March 19, 2024, 10:00–10:15, H 1028

Effect of cell-cell interactions on the collective behaviour of gliding Chlamydomonas populations — •Alexandros Fragkopoulos, Justin Nevells, Timo Völkl, and Oliver Bäumchen — University of Bayreuth, Experimental Physics V, 95447 Bayreuth, Germany

Cilia and flagella represent universal tools enabling cells and microbes to propel themselves in diverse environments. In the case of the unicellular biflagellated microbe Chlamydomonas reinhardtii, the flagella are used not only to swim in the surrounding medium, but also to adhere to surfaces. In this adhered state, a second flagella-mediated motility mode is observed, during which the cells glide along the surface. This is achieved by means of force transduction through an intraflagellar transport machinery. We recently showed that gliding C. reinhardtii cells form weak clusters, most likely assisted by mechanosensing of their flagella [1]. Here we show that Chlamydomonas noctigama, a close relative of C. reinhardtii, exhibits significantly stronger cell-cell interactions, resulting in pronounced cell clustering even at low densities. In addition, we observe that C. noctigama preferentially attach nearby other cells. Finally, we use morphological tools to quantify and compare the clusters to C. reinhardtii. By understanding the changes of the cell-cell interactions between the species, we aim to dissect their contribution to the observed cell clustering.

[1] Till et al., Phys. Rev. Res. 4, L042046 (2022).

Keywords: Chlamydomonas; cell-cell interactions; collective behaviour