Biophysics

In http://doi.org/10.1073/pnas.1422922112 we investigated the directed movement of the alga Euglena gracilis towards light sources and the dependence of the movement response on the intensity profile of light. We proposed a generalized receptor law inferred from experimental data which accounts for the directed movement of algae towards light at low light intensities (positive phototaxis) and the movement in the opposite direction at higher light intensities (negative phototaxis).