title: Elevated Rate of Genome Rearrangements in Radiation-Resistant Bacteria.
abstract: A number of bacterial, archaeal, and eukaryotic species are known for their resistance to ionizing radiation. One of the challenges these species face is a potent environmental source of DNA double-strand breaks, potential drivers of genome structure evolution. Efficient and accurate DNA double-strand break repair systems have been demonstrated in several unrelated radiation-resistant species and are putative adaptations to the DNA damaging environment. Such adaptations are expected to compensate for the genome-destabilizing effect of environmental DNA damage and may be expected to result in a more conserved gene order in radiation-resistant species. However, here we show that rates of genome rearrangements, measured as loss of gene order conservation with time, are higher in radiation-resistant species in multiple, phylogenetically independent groups of bacteria. Comparison of indicators of selection for genome organization between radiation-resistant and phylogenetically matched, nonresistant species argues against tolerance to disruption of genome structure as a strategy for radiation resistance. Interestingly, an important mechanism affecting genome rearrangements in prokaryotes, the symmetrical inversions around the origin of DNA replication, shapes genome structure of both radiation-resistant and nonresistant species. In conclusion, the opposing effects of environmental DNA damage and DNA repair result in elevated rates of genome rearrangements in radiation-resistant bacteria.
authors.affiliation: Division of Molecular Biology, Ruder Boskovic Institute, 10000 Zagreb, Croatia jelena.repar@irb.hr.|Medical Research Council London Institute of Medical Sciences, W12 0NN, United Kingdom.|Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, W12 0NN, United Kingdom.
authors.forename: Jelena
authors.identifier: 0000-0002-7761-054X
authors.initials: J
authors.lastname: Repar
authors.affiliation: Division of Electronics, Ruder Boskovic Institute, 10000 Zagreb, Croatia.|Systems Biology Research Unit, European Molecular Biology Laboratory/Centre for Genomic Regulation, 08003 Barcelona, Spain.|Universitat Pompeu Fabra, 08002 Barcelona, Spain.
authors.forename: Fran
authors.identifier: 0000-0002-7811-6711
authors.initials: F
authors.lastname: Supek
authors.affiliation: Division for Marine and Environmental Research, Ruder Boskovic Institute, 10000 Zagreb, Croatia.
authors.forename: Tin
authors.identifier: 0000-0002-9341-344X
authors.initials: T
authors.lastname: Klanjscek
authors.affiliation: Medical Research Council London Institute of Medical Sciences, W12 0NN, United Kingdom.|Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, W12 0NN, United Kingdom.
authors.forename: Tobias
authors.identifier: 0000-0002-4936-5428
authors.initials: T
authors.lastname: Warnecke
authors.affiliation: Division of Molecular Biology, Ruder Boskovic Institute, 10000 Zagreb, Croatia.
authors.forename: Ksenija
authors.initials: K
authors.lastname: Zahradka
authors.affiliation: Division of Molecular Biology, Ruder Boskovic Institute, 10000 Zagreb, Croatia.
authors.forename: Davor
authors.initials: D
authors.lastname: Zahradka
mesh_terms: D034301:Deinococcus / Q000235:genetics* / Q000528:radiation effects; D005720:Gamma Rays; D016680:Genome, Bacterial; D042822:Genomic Instability; D056914:Genomic Structural Variation; D011836:Radiation Tolerance / Q000235:genetics*; D012641:Selection, Genetic
keywords: Deinococcus radiodurans; gamma radiation; gene order; genome stability; synteny