Induction and Repair of DNA Double-Strand Breaks under Irradiation and Microgravity

• Published in: Radiation research Vol. 153; no. 5; pp. 521 - 525
• Main Authors: Pross, H. D., Casares, A., Kiefer, J.
• Format: Journal Article
• Language: English
• Published: Oak Brook, Il Radiation Research Society 01-05-2000
• Subjects: Biological and medical sciences; Cooling; DNA Damage; DNA Repair; DNA, Fungal - radiation effects; Dosimetry; Fundamental and applied biological sciences. Psychology; Gravity; Irradiation; Lymphocytes; Microgravity; Molecular and cellular biology; Molecular genetics; Mutagenesis. Repair; Radiation damage; Radiation dosage; REGULAR ARTICLES; Saccharomyces cerevisiae - genetics; Space Flight; Space life sciences; Temperature; Weightlessness; Yeasts; Cell culture; Temperature effect; Space flight; Fungi; Double strand break; Ionizing radiation; DNA; Radiation injury; Ascomycetes; Biological effect; Repair; Microgravity; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0033-7587; 1938-5404
• DOI: 10.1667/0033-7587(2000)153[0521:IARODD]2.0.CO;2

Pross, H. D., Casares, A. and Kiefer, J. Induction and Repair of DNA Double-Strand Breaks under Irradiation and Microgravity. The influence of microgravity on induction and repair of double-strand breaks was studied in the yeast mutant rad54-3, which is temperature-conditional for the repair of DNA double-strand breaks. The experiment was performed on the shuttle Atlantis flight STS-84. Cell samples were kept at 0–4°C until they reached orbit, where they were transferred to 22 (permissive temperature for repair) and 37°C (restrictive temperature). They were exposed to graded doses of β particles from an in-built 63Ni source during the repair period. After 152 h in microgravity, the radiation exposure was stopped, and the samples were returned to low-temperature conditions, where they remained until final evaluation in the home laboratory. The amount of double-strand breaks remaining was estimated from the differences in survival after plating and incubation at the restrictive temperature. The results show that there is no significant difference for both the induction and the repair of double-strand breaks between microgravity and terrestrial conditions.