@misc{oai:repo.qst.go.jp:00063958,
 author = {Munakata, Nobuo and Natsume, Toshiyuki and Konishi, Teruaki and Hieda, Kotaro and Panitz, Corinna and Horneck, Gerda and et.al and 小西 輝昭 and 檜枝 光太郎},
 month = {Jul},
 note = {Rifampicin-resistant mutants were collected from the spores of three B. subtilis strains, HA101(HA, repair profecient), TKJ6312 (US, UV-repair defective) and TKJ6412 (RF, recombination defecient) grown after exposure to various radiations and simulated space environments. All of 563 mutations analyzed carried sequence changes in the N-terminal region of the rpoB gene codingfor the subunit beta of RNA polymerase II and belonged to 56 alleles. (1) Most of spontaneous mutants from the three strains belonged to 13 single-base substitution (SBS) alleles, exceptions
(<2%) being one 3 bp insertion and one tandem double substitution (TDS). (2) About 6 % and 16 % of the mutations from the HA and RF spores, respectively, exposed to ionizing radiations were complex mutations including multiple-base substitutions, insertions and deletions. Several TDS and non-tandem double substitutions (NTDS), and 3, 6, 9 and one 30 bp deletions seem to provide signatures of the exposure to ionizing radiations. (3) Except one TDS from US and one NTDS from HA spores, UV or solar exposure seemed not to leave unique footprints. (4) In space simulation experiments, the only conditions involving high vacuum consistently increased the mutation frequency, and exhibited high occurrences (>50%) of TDS. In HA spores, the allele r201 (CA to TT at 1460) was the most frequent, while in US spores, another allele r210(TC to AA at 1404) was the most frequent. In conclusion, some of the conditions encountered in space environments, such as space vacuum and ionizing radiations, could produce unique mutational signatures in the rpoB gene of B. subtilis spores., COSPAR},
 title = {Signature mutations from B. subtilis spores exposed to radiations and simulated space environments},
 year = {2010}
}