title: The effects of microgravity on induced mutation in Escherichia coli and Saccharomyces cerevisiae.
abstract: We examined whether microgravity influences the induced-mutation frequencies through in vivo experiments during space flight aboard the space shuttle Discovery (STS-91). We prepared dried samples of repair-deficient strains and parental strains of Escherichia (E.) coli and Saccharomyces (S.) cerevisiae given DNA damage treatment. After culture in space, we measured the induced-mutation frequencies and SOS-responses under microgravity. The experimental findings indicate that almost the same induced-mutation frequencies and SOS-responses of space samples were observed in both strains compared with the ground control samples. It is suggested that microgravity might not influence induced-mutation frequencies and SOS-responses at the stages of DNA replication and/or DNA repair. In addition, we developed a new experimental apparatus for space experiments to culture and freeze stocks of E. coli and S. cerevisiae cells.
authors.affiliation: Department of Biology, Nara Medical University, Kashihara, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Ohnishi
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Masukawa
authors.forename: K
authors.initials: K
authors.lastname: Sekikawa
authors.forename: T
authors.initials: T
authors.lastname: Amano
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: S
authors.initials: S
authors.lastname: Nagaoka
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D002470:Cell Survival / Q000528:radiation effects; D003359:Cosmic Radiation; D004249:DNA Damage; D004260:DNA Repair; D004867:Equipment Design; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D008770:Methylnitrosourea / Q000494:pharmacology; D009154:Mutation; D013014:SOS Response, Genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000528:radiation effects; D013026:Space Flight / Q000295:instrumentation*; D014466:Ultraviolet Rays; D014893:Weightlessness; D014965:X-Rays
chemical_list: D000477:Alkylating Agents; D008770:Methylnitrosourea