Print Email Facebook Twitter Fibrous Flagellar Hairs of Chlamydomonas reinhardtii Do Not Enhance Swimming Title Fibrous Flagellar Hairs of Chlamydomonas reinhardtii Do Not Enhance Swimming Author Amador, G.J. (TU Delft Fluid Mechanics; Kavli institute of nanoscience Delft) Wei, D. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft) Tam, D.S.W. (TU Delft Fluid Mechanics) Aubin-Tam, M.E. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft) Date 2020 Abstract The flagella of Chlamydomonas reinhardtii possess fibrous ultrastructures of a nanometer-scale thickness known as mastigonemes. These structures have been widely hypothesized to enhance flagellar thrust; however, detailed hydrodynamic analysis supporting this claim is lacking. In this study, we present a comprehensive investigation into the hydrodynamic effects of mastigonemes using a genetically modified mutant lacking the fibrous structures. Through high-speed observations of freely swimming cells, we found the average and maximum swimming speeds to be unaffected by the presence of mastigonemes. In addition to swimming speeds, no significant difference was found for flagellar gait kinematics. After our observations of swimming kinematics, we present direct measurements of the hydrodynamic forces generated by flagella with and without mastigonemes. These measurements were conducted using optical tweezers, which enabled high temporal and spatial resolution of hydrodynamic forces. Through our measurements, we found no significant difference in propulsive flows due to the presence of mastigonemes. Direct comparison between measurements and fluid mechanical modeling revealed that swimming hydrodynamics were accurately captured without including mastigonemes on the modeled swimmer's flagella. Therefore, mastigonemes do not appear to increase the flagella's effective area while swimming, as previously thought. Our results refute the longstanding claim that mastigonemes enhance flagellar thrust in C. reinhardtii, and so, their function still remains enigmatic. To reference this document use: http://resolver.tudelft.nl/uuid:62ce4882-9aa7-4611-a716-7d73dd9f72aa DOI https://doi.org/10.1016/j.bpj.2020.05.003 ISSN 0006-3495 Source Biophysical Journal, 118 (12), 2914–2925 Part of collection Institutional Repository Document type journal article Rights © 2020 G.J. Amador, D. Wei, D.S.W. Tam, M.E. Aubin-Tam Files PDF 1_s2.0_S0006349520303994_main.pdf 2.05 MB Close viewer /islandora/object/uuid:62ce4882-9aa7-4611-a716-7d73dd9f72aa/datastream/OBJ/view