A steering mechanism for phototaxis in Chlamydomonas

J R Soc Interface. 2015 Mar 6;12(104):20141164. doi: 10.1098/rsif.2014.1164.


Chlamydomonas shows both positive and negative phototaxis. It has a single eyespot near its equator, and as the cell rotates during the forward motion, the light signal received by the eyespot varies. We use a simple mechanical model of Chlamydomonas that couples the flagellar beat pattern to the light intensity at the eyespot to demonstrate a mechanism for phototactic steering that is consistent with observations. The direction of phototaxis is controlled by a parameter in our model, and the steering mechanism is robust to noise. Our model shows switching between directed phototaxis when the light is on and run-and-tumble behaviour in the dark.

Keywords: cell locomotion; flagella; phototaxis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Biophysics
  • Chlamydomonas / physiology*
  • Flagella / physiology
  • Light*
  • Models, Biological
  • Movement
  • Reproducibility of Results