[BAO01-P10] Mutation analysis of the rpoB gene in the radiation-resistant bacterium Deinococcus radiodurans R1 exposed to space
Keywords:Deinococcus radiodurans R1, DNA damage, Tanpopo mission, mutation analysis, rpoB gene, rifampicin
D. radiodurans R1 cell suspension was dropped in the wells of aluminum plates and dried under vacuum (vacuum-dried). The dried cells were exposed to space, stored in the ISS cabin or in the ground laboratory. After exposure experiment, the cells recovered from each well were used to mix with 10 ml of mTGE medium and cultured until OD590 nm reached between 1.1 and 3.0. The culture was plated on mTGE agar supplemented by 50 µg/ml rifampicin to determine the number of rifampicin resistant cells (RifR), and on mTGE agar without rifampicin to determine the total number of viable cells. We also determined DNA sequences of the rpoB gene extracted from RifR.
The mutant frequencies of space exposed cells and ground control were comparable (Fig. 1). The result suggested that the effect of UV on mutation induction was marginal in dried deinococcal cells exposed to space for about one year. Further, we will report and discuss the mutation spectra of the rpoB gene in rifampicin-resistant cells obtained from samples exposed to space, stored in the ISS cabin or in the ground laboratory.
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