Issue 9, 2006

Cellular responses of the ciliate, Tetrahymena thermophila, to far infrared irradiation

Abstract

Infrared rays from sunlight permeate the earth's atmosphere, yet little is known about their interactions with living organisms. To learn whether they affect cell structure and function, we tested the ciliated protozoan, Tetrahymena thermophila. These unicellular eukaryotes aggregate in swarms near the surface of freshwater habitats, where direct and diffuse solar radiation impinge upon the water–air interface. We report that populations irradiated in laboratory cultures grew and mated normally, but major changes occurred in cell physiology during the stationary phase. Early on, there were significant reductions in chromatin body size and the antibody reactivity of methyl groups on lysine residues 4 and 9 in histone H3. Later, when cells began to starve, messenger RNAs for key proteins related to chromatin structure, intermediary metabolism and cellular motility increased from two- to nearly nine-fold. Metabolic activity, swimming speed and linearity of motion also increased, and spindle shaped cells with a caudal cilium appeared. Our findings suggest that infrared radiation enhances differentiation towards a dispersal cell-like phenotype in saturated populations of Tetrahymena thermophila.

Graphical abstract: Cellular responses of the ciliate, Tetrahymena thermophila, to far infrared irradiation

Supplementary files

Article information

Article type
Paper
Submitted
06 Feb 2006
Accepted
22 Jun 2006
First published
04 Aug 2006

Photochem. Photobiol. Sci., 2006,5, 799-807

Cellular responses of the ciliate, Tetrahymena thermophila, to far infrared irradiation

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, 5, 799 DOI: 10.1039/B601741J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements