Biophysical Modeling of Light-Dependent Movement in Euglena Gracilis

Monday

Tsang Alan Tsang Cheng Hou, Assistant Professor, University of Hong Kong and Ingmar Riedel-Kruse, Associate Professor, Molecular and Cellular Biology, University of Arizona, recently published a paper PNAS titled "Light-dependent switching between two flagellar beating states selects versatile phototaxis strategies in microswimmers".

The study explores how a single-celled organism called Euglena gracilis reacts to different light intensities. Euglena can move towards light (positive phototaxis) when the light is dim and away from light (negative phototaxis) when the light is very bright. This ability helps the organism optimize photosynthesis and avoid damage from strong light.

Researchers identified a mechanism called "photoresponse inversion" in Euglena. This mechanism allows the organism to switch between two types of movement based on light intensity. At low light, Euglena swims straight, while at high light, it turns and changes direction. This switch is controlled by the beating of its flagellum, a whip-like structure that helps it move.

The study also suggests that understanding these mechanisms in Euglena can provide insights into the behavior of other microorganisms and help design synthetic microswimmers for applications like environmental cleanup and sustainable bioeconomy.

There are several potential applications of the findings:

  1. Understanding Microorganisms: The insights into how Euglena gracilis responds to light can help scientists better understand the behavior of other microorganisms. This knowledge can be applied to study various species and their navigation strategies.
  2. Bioremediation: The mechanisms discovered could be used to design synthetic microswimmers that can navigate and clean up environmental pollutants. These microswimmers could be engineered to move towards or away from specific stimuli, making them effective in targeted bioremediation efforts.
  3. Sustainable Bioeconomy: By understanding the principles behind Euglena's movement, researchers can develop new technologies that support a sustainable bioeconomy. This includes creating bio-inspired robots or systems that can perform tasks such as monitoring environmental conditions or delivering targeted treatments in medical applications.