title: Anaerobically Grown Escherichia coli Has an Enhanced Mutation Rate and Distinct Mutational Spectra.
abstract: Oxidative stress is a major cause of mutation but little is known about how growth in the absence of oxygen impacts the rate and spectrum of mutations. We employed long-term mutation accumulation experiments to directly measure the rates and spectra of spontaneous mutation events in Escherichia coli populations propagated under aerobic and anaerobic conditions. To detect mutations, whole genome sequencing was coupled with methods of analysis sufficient to identify a broad range of mutational classes, including structural variants (SVs) generated by movement of repetitive elements. The anaerobically grown populations displayed a mutation rate nearly twice that of the aerobic populations, showed distinct asymmetric mutational strand biases, and greater insertion element activity. Consistent with mutation rate and spectra observations, genes for transposition and recombination repair associated with SVs were up-regulated during anaerobic growth. Together, these results define differences in mutational spectra affecting the evolution of facultative anaerobes.
authors.affiliation: AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand.|New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand.
authors.forename: Sonal
authors.initials: S
authors.lastname: Shewaramani
authors.affiliation: AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand.|New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Finn
authors.affiliation: AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Sinead C
authors.identifier: 0000-0002-5461-6738
authors.initials: SC
authors.lastname: Leahy
authors.affiliation: Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Rees
authors.initials: R
authors.lastname: Kassen
authors.affiliation: New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand.|Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, Germany.|Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), CNRS UMR 8231, PSL Research University, Paris, France.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Rainey
authors.affiliation: AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Christina D
authors.identifier: 0000-0001-9692-9559
authors.initials: CD
authors.lastname: Moon
mesh_terms: D000693:Anaerobiosis; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics; D005787:Gene Frequency; D059645:Mutation Rate; D010100:Oxygen / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D010100:Oxygen