1. Department of Genetics, School of Medicine
2. Radioisotope Center, Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8102, Japan.
3. International Radiation Information Center, Research Institute for Nuclear Medicine and Biology , Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-0037, Japan.
4. Division of Accelerator Research
5. Space and Particle Radiation Science, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-0024, Japan.
6. MRC, Radiation and Genome Stability Unit, Harwell, Oxfordshire OX11 0RD, UK.
7. Radiation Biology Center, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto 606-8315, Japan.