Format

Send to

Choose Destination
Biophys J. 2019 Apr 2;116(7):1292-1304. doi: 10.1016/j.bpj.2019.02.012. Epub 2019 Feb 26.

How Does Cilium Length Affect Beating?

Author information

1
Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri; Department of Genetics, Washington University in St. Louis, St. Louis, Missouri.
2
Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri.
3
Department of Genetics, Washington University in St. Louis, St. Louis, Missouri.
4
Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri. Electronic address: pvb@wustl.edu.

Abstract

The effects of cilium length on the dynamics of cilia motion were investigated by high-speed video microscopy of uniciliated mutants of the swimming alga, Chlamydomonas reinhardtii. Cells with short cilia were obtained by deciliating cells via pH shock and allowing cilia to reassemble for limited times. The frequency of cilia beating was estimated from the motion of the cell body and of the cilium. Key features of the ciliary waveform were quantified from polynomial curves fitted to the cilium in each image frame. Most notably, periodic beating did not emerge until the cilium reached a critical length between 2 and 4 μm. Surprisingly, in cells that exhibited periodic beating, the frequency of beating was similar for all lengths with only a slight decrease in frequency as length increased from 4 μm to the normal length of 10-12 μm. The waveform average curvature (rad/μm) was also conserved as the cilium grew. The mechanical metrics of ciliary propulsion (force, torque, and power) all increased in proportion to length. The mechanical efficiency of beating appeared to be maximal at the normal wild-type length of 10-12 μm. These quantitative features of ciliary behavior illuminate the biophysics of cilia motion and, in future studies, may help distinguish competing hypotheses of the underlying mechanism of oscillation.

PMID:
30878201
PMCID:
PMC6451027
[Available on 2020-04-02]
DOI:
10.1016/j.bpj.2019.02.012

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center