title: Genomic DNA of Nostoc commune (Cyanobacteria) becomes covalently modified during long-term (decades) desiccation but is protected from oxidative damage and degradation.
abstract: Genomic DNA of Nostoc commune (Cyanobacteria) became covalently modified during decades of desiccation. Amplification of gene loci from desiccated cells required pretreatment of DNA with N-phenacylthiazolium bromide, a reagent that cleaves DNA- and protein-linked advanced glycosylation end-products. DNA from 13 year desiccated cells did not show any higher levels of the commonly studied oxidatively modified DNA damage biomarkers 8-hydroxyguanine, 8-hydroxyadenine and 5-hydroxyuracil, compared to commercially available calf thymus DNA. Different patterns of amplification products were obtained with DNA from desiccated/rehydrating cells and a liquid culture derived from the dried material, using the same set of primers. In contrast, a reproducible fingerprint was obtained, irrespective of time of rehydration of the DNA, using a primer (5'-GWCWATCGCC-3') based upon a highly iterated palindromic repeat sequence present in the genome. In vitro, the desiccation of cccDNA led to loss of supercoiling, aggregation, loss of resolution during agarose gel electrophoresis and loss of transformation and transfection efficiency. These changes were minimized when DNA was desiccated and stored in the presence of trehalose, a non-reducing disaccharide present in Nostoc colonies. The response of the N.commune genome to desiccation is different from the response of the genomes of cyanobacteria and Deinococcus radiodurans to ionizing radiation.
authors.affiliation: Virginia Tech Center for Genomics (VIGEN), Virginia Tech, Blacksburg, VA 24061, USA.
authors.forename: Breanne
authors.initials: B
authors.lastname: Shirkey
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: McMaster
authors.forename: Sue C
authors.initials: SC
authors.lastname: Smith
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Wright
authors.forename: Henry
authors.initials: H
authors.lastname: Rodriguez
authors.forename: Pawel
authors.initials: P
authors.lastname: Jaruga
authors.forename: Mustafa
authors.initials: M
authors.lastname: Birincioglu
authors.forename: Richard F
authors.initials: RF
authors.lastname: Helm
authors.forename: Malcolm
authors.initials: M
authors.lastname: Potts
mesh_terms: D000458:Cyanobacteria / Q000235:genetics* / Q000254:growth & development; D004249:DNA Damage; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D003890:Desiccation; D016680:Genome, Bacterial; D018384:Oxidative Stress; D019105:Random Amplified Polymorphic DNA Technique; D012091:Repetitive Sequences, Nucleic Acid; D013997:Time Factors
chemical_list: D004269:DNA, Bacterial