Analysis of radiation-induced mutation using transgenic mice

For examining the mutagenicity of chemicals in the animal species more close to human, transgenic mice such as MutaTM, Big BlueTM, (supF), gpt delta, (rpsL) and Line60 were developed and analytical investigations for radiation-induced mutation using these animals were reviewed in this paper. The mice with phage vector (the first four of the above strains) are only used to detect the chromosomal deletion of less than 10 kb and for those with plasmid vector (the 5th and 6th strains), especially for Line60, the author analyzed the mutation induced by X-ray with doses as high as 50 and 100 Gy in the brain and spleen. The large deletion was found detectable in the strain, however, the sensitivity was not satisfactory because the high doses were required. Since mutagenic effect can be examined and analyzed on various tissues and organs of the mice, they are conceivably useful for studying the relationship between the mutation and carcinogenesis or aging although many problems remain to be solved. (K.H.)