title: Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs.
abstract: In order to investigate whether eggs of the black-striped strain (P(S)) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 degrees C than those kept at 25 degrees C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/microm. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation.
authors.affiliation: Department of Applied Biology, Faculty of Textile Science, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kotani
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Furusawa
authors.forename: Shunji
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Kumie
authors.initials: K
authors.lastname: Nojima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujii
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sugimura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ichida
authors.forename: Eiko
authors.initials: E
authors.lastname: Suzuki
authors.forename: Aiko
authors.initials: A
authors.lastname: Nagamatsu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Todo
authors.forename: Mituo
authors.initials: M
authors.lastname: Ikenaga
mesh_terms: D000818:Animals; D012831:Bombyx / Q000196:embryology / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects*; D004625:Embryo, Nonmammalian / Q000528:radiation effects; D005787:Gene Frequency; D020450:Heavy Ions; D007814:Larva; D018499:Linear Energy Transfer; D009154:Mutation; D010063:Ovum / Q000528:radiation effects*; D012062:Relative Biological Effectiveness