A supplement providing a snapshot of the latest developments in chemical biology
23 August 2006
Infrared light can help hungry, water-dwelling protozoa adopt a sleeker, faster-swimming form, allowing them to disperse in search of new food sources. The tactic could be an evolutionary adaptation that helps populations of Tetrahymena thermophila to weather lean times, a team of Japanese and US scientists report.
To investigate how IR affects single cells, Shiurba and his colleagues studied the protozoan T. thermophila. In its freshwater environment it tends to swim upwards, gathering near the water surface in a teeming swarm where there is more oxygen, edible debris - and sunlight.
These cells swam almost half again as fast as those in the control culture that was not exposed to IR light. They also followed much straighter trajectories. When competition for food reaches a maximum, transformation greatly increases a cell's odds of survival, suggested Shiurba. In future work, the group hopes to work out the molecular basis of this phenomenon.
R Shiurba, T Hirabayashi, M Masuda, A Kawamura, Y Komoike, W Klitz, K Kinowaki, T Funatsu, S Kondo, S Kiyokawa, T Sugai, K Kawamura, H Namiki and T Higashinakagawa, Photochem. Photobiol. Sci., 2006