Repair and recombination of X-irradiated plasmids in Xenopus laevis oocytes

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Molecular and Cellular Biology; (USA)

DOI:https://doi.org/10.1128/MCB.10.11.5849· OSTI ID:6270779

Sweigert, S E; Carroll, D ^[1]

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1. Univ. of Utah Health Sciences Center, Salt Lake City (USA)

Plasmid DNA substrates were X-irradiated and injected into the nuclei of Xenopus laevis oocytes. After incubation for 20 h, DNA was recovered from the oocytes and analyzed simultaneously for repair and for intermolecular homologous recombination by electrophoresis and bacterial transformation. Oocyte-mediated repair of DNA strand breaks was observed with both methods. Using a repair-deficient mutant Escherichia coli strain and its repair-proficient parent as hosts for the transformation assay, we also demonstrated that oocytes repaired oxidative-type DNA base damage induced by X-rays. X-irradiation of a circular DNA stimulated its potential to recombine with a homologous linear partner. Recombination products were detected directly by Southern blot hybridization and as bacterial transformant clones expressing two antibiotic resistance markers originally carried separately on the two substrates. The increase in recombination was dependent on X-ray dose. There is some suggestion that lesions other than double-strand breaks contribute to the stimulation of oocyte-mediated homologous recombination. In summary, oocytes have considerable capacity to repair X-ray-induced damage, and some X-ray lesions stimulate homologous recombination in these cells.

• OSTI ID: 6270779
• Journal Information: Molecular and Cellular Biology; (USA), Journal Name: Molecular and Cellular Biology; (USA) Vol. 10:11; ISSN MCEBD; ISSN 0270-7306
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
CELL NUCLEI
DNA
DNA REPAIR
ELECTROMAGNETIC RADIATION
ELECTROPHORESIS
FROGS
GENE MUTATIONS
GENE RECOMBINATION
GERM CELLS
IONIZING RADIATIONS
MUTATIONS
NUCLEIC ACIDS
OOCYTES
ORGANIC COMPOUNDS
PLASMIDS
RADIATIONS
RADIOINDUCTION
RECOVERY
REPAIR
STRAND BREAKS
VERTEBRATES
X RADIATION