Radiation-induced Germ-line Mutations Detected by a Direct Comparison of Parents and Children DNA Sequences Containing SNPs

Abstract

Germ-line mutation is detected in mice but not in humans. To estimate genetic risk of humans, a new approach to detect radiation-induced mutations in man is expected. We have developed a new method to detect germ-line mutations by directly comparing DNA sequences of parents and children. The nucleotide sequences of STS markers containing SNPs of parents and children DNA were determined by a direct sequencing. At each radiation dose, 5 Mb DNA sequences were determined. We found 7 deletions and 1 point mutation in 3 Gy irradiated mice but not in 1 Gy and control mice. The mutation frequency was about 5.3 × 10-7/bp/Gy or 2.2 × 10-4/locus/Gy, and suggested the non-linear increase of mutation rate with dose. [J Radiat Res 44:434 (2003)]