Analysis of the Effect of Space Radiations on the Nematode, Caenorhabditis elegans, through the Simulated Space Radiation

Abstract

In this study, we simulated space flight of the nematode, Caenorhabditis elegans, on the ground and examined how it isaffected by space radiation and G-forces. We simulated G-forces during launchin a gravity acceleration laboratory device in order to identify and isolatethe effects of the G-forces. Following this, we irradiated C. elegans with accelerated protons (MC-50 Cyclotron) and gammarays (iR 222 machine) at the same physical dose. We calculated the expectedradiation dose according to Reitz [1] and simulation programs (NASA AP8MIN [2],NASA AE8MAX [2], and CREAM86 [3]) for 1 month (dose rate: 6 × 10-3 Gy; 2.8 × 10-2 Gy), 6 months (dose rate: 36 × 10-3 Gy; 16.8× 10-2 Gy), and 2 years (dose rate: 144 × 10-3 Gy; 67.2 × 10-2 Gy) of space flight. There have beenseveral trials that aimed to take C.elegans into orbit on US space shuttle missions including a mission onthe shuttle Columbia. In this study, we simulated longer duration space flightsand performed a whole-genome microarray analysis to observe phenotype variationswhereas most such experiments were carried out during short duration space flightsand focused on mutations and genotypic variations. We expect that theresults of this study will be useful to predict the effects of long-termexposure of space radiation on living organisms.