Nutritional conditions and oxygen concentration affect spontaneous occurrence of homologous recombination events but not spontaneous mutagenesis in <i>Escherichia coli</i>

DOI Web Site Web Site PubMed 17 References
  • Le Lan Anh Thi
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Chang Phooi Yee
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Ando Sayaka
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Conrad Thomas M.
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Nunose Shohei
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Sakai Akiko
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Uefune Haruka
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Furukohri Asako
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Akiyama Masahiro Tatsumi
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology
  • Maki Hisaji
    Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology

Bibliographic Information

Other Title
  • Nutritional conditions and oxygen concentration affect spontaneous occurrence of homologous recombination events but not spontaneous mutagenesis in Escherichia coli

Search this article

Abstract

<p>Effects of environmental factors for growth of Escherichia coli on spontaneous mutagenesis and homologous recombination events are described. By analyzing rifampicin-resistant (Rifr) mutation frequencies in an E. coli strain lacking MutM and MutY repair enzymes, which suppress base substitution mutations caused by 8-oxoguanine (7,8 dihydro-8-oxoguanine; 8-oxoG) in DNA, we examined levels of oxidative DNA damage produced in normally growing cells. The level of 8-oxoG DNA damage was about 9- and 63-fold higher in cells grown in M9-glucose and M9-glycerol media, respectively, than in those grown in LB medium. We also found that about 14-fold more 8-oxoG DNA damage was produced in cells grown in about 0.1% oxygen than in those grown in the normal atmosphere. However, Rifr mutation frequency in wild-type cells was unchanged in such different growth conditions, suggesting that the capacity of repair mechanisms is sufficient to suppress mutations caused by 8-oxoG even at very high levels in cells growing in the particular conditions. On the other hand, the frequency of spontaneous homologous recombination events in wild-type E. coli cells varied with different growth conditions. When cells were grown in M9-glucose and M9-glycerol media, the spontaneous recombination frequency increased to about 4.3- and 7.3-fold, respectively, higher than that in LB medium. Likewise, the spontaneous recombination frequency was about 3.5-fold higher in cells growing in the hypoxic condition than in cells growing in the atmosphere. When cells were grown in anaerobic conditions, the recombination frequency decreased to half of that in the atmosphere. These data indicated that spontaneous homologous recombination is highly responsive to environmental factors such as nutrition and oxygen concentration.</p>

Journal

References(17)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top