X-ray- and ultraviolet-radiation-induced mutations in Muta mouse.
To evaluate the usefulness of the transgenic Muta mouse for investigating radiation-induced mutations in vivo, we have examined the effects of whole-body X irradiation and compared them to the effects of ultraviolet light. The spontaneous mutation frequencies in young adults were about 7 x 10(-5) in the spleen, liver and skin. The mutation frequencies 1 week after a lethal dose of X radiation (8 Gy) were 3.2, 2.6 and 2.7 times the spontaneous levels in the spleen, liver and skin, respectively. When the skin was irradiated with 10 kJ m-2 of UVB, the mutation frequency increased about 6 times. The mutation frequencies induced by an acute dose of 4 Gy or by a fractionated dose of 11.7 Gy (0.15 Gy x 78 times, 3 times/week) in the spleen and liver were less than 2-fold the spontaneous levels at 16 weeks after irradiation. A comparison of X and UV radiation was also conducted with cultured cells derived from the mouse embryo. UVC of 5 J m-2 raised the mutation frequency to 15 times that of unirradiated cells, while 10 Gy X rays raised it 2.6 times. The findings indicate that the Muta mouse is less sensitive to X-ray-induced mutation than UV-induced mutation.
Ono
T
T
Department of Radiation Research, Tohoku University School of Medicine, Sendai, Japan.
Ikehata
H
H
Hosoi
Y
Y
Shung
B S
BS
Kurishita
A
A
Wang
X
X
Yamamoto
K
K
Suzuki
T
T
Sofuni
T
T
D000818:Animals; D002478:Cells, Cultured; D051379:Mice; D009154:Mutation / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014965:X-Rays