Behavioral Resistance of Caenorhabditis elegans Against High-LET Radiation Exposure

Abstract

Effects of high linear energy transfer (LET) radiation on the functions of the nervous system is a potential risk in interplanetary manned space missions. However, little is known about how the nervous system is protected against high-LET radiation exposure. The analysis of high-LET radiation resistant animals would be therefore important for space missions. Here, we investigated the resistance to high-LET radiation exposure for two behaviors of the nematode, Caenorhabditis elegans, which is known as a model organism for the nervous system. Tested behaviors were locomotion and chemotaxis to NaCl. In addition, egg hatchability was examined as an indicator of high-LET radiation sensitivity. Relative biological effectiveness (RBE) of high-LET radiation (¹²C, 18.3 MeV/u, LET = 113 keV/μm) relative to low-LET radiation for hatchability was 4.5, whereas RBEs for locomotion and chemotaxis were 1.4 and 1.1, respectively. This study shows that the behavioral system for locomotion and chemotaxis of C. elegans is highly resistant to high-LET radiation exposure.