title: Mutation frequency of Dictyostelium discoideum spores exposed to the space environment.
abstract: Two strains of cellular slime mold Dictyostelium discoideum, a radiosensitive mutant and the parental wild-type strain, were used to investigate the effects of cosmic radiation on viability and mutation frequency at the spore stage for about 9 days in Space Shuttle of NASA. We measured little effect of space environment on viability and cell growth in the both strains as compared to ground controls. The mutation frequency of the flown spores were similar to that of ground control. These results suggest that there could be no effect of cosmic radiation, containing high linear energy transfer radiation at about 0.9 mSv/day as detected by real-time radiation monitoring device on the induction of mutation at the spore stage.
authors.affiliation: Department of Biology, Nara Medical University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Fukui
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: S
authors.initials: S
authors.lastname: Nagaoka
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D000818:Animals; D003359:Cosmic Radiation; D004023:Dictyostelium / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects*; D018499:Linear Energy Transfer; D016296:Mutagenesis; D009154:Mutation; D011836:Radiation Tolerance; D011874:Radiometry; D013026:Space Flight; D013170:Spores / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects*; D013819:Thermoluminescent Dosimetry; D014893:Weightlessness