DNA strand breaks, repair, and survival in x-irradiated mammalian cells.

Journal Article · Mon Mar 01 04:00:00 EST 1976 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.73.3.809· OSTI ID:4065649

Dugle, D. L.; Gillespie, C. J.; Chapman, J. D.

The yields of unrepairable single-and double-strand breaks in the DNA of x-irradiated Chinese hamster cells were measured by low-speed neutral and alkaline sucrose density gradient sedimentation in order to investigate the relation between these lesions and reproductive death. After maximal single-strand remoining, at all doses, the number of residual single-strand breaks was twice the number of residual double-strand breaks. Both double-strand and unrepairable single-strand breaks were proportional to the square of absorbed dose, in the range 10-50 krad. No rejoining of double-strand breaks was observed. These observations suggest that, in mammalian cells, most double-strand breaks are not repairable, while all single-strand breaks are repaired except those that are sufficiently close on complementary strands to constitute double-strand breaks. Finally, comparison with cell survival measurements at much lower doses suggests that loss of reproductive capacity corresponds to induction of approximately one double-strand break.

• Research Organization: Atomic Energy of Canada, Ltd., Manitoba
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-029549
• OSTI ID: 4065649
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 3 Vol. 73; ISSN 0027-8424
• Publisher: National Academy of Sciences, Washington, DC (United States)
• Country of Publication: United States
• Language: English

Related Subjects

*ANIMAL CELLS-- BIOLOGICAL RADIATION EFFECTS
*DNA-- STRAND BREAKS
*STRAND BREAKS-- BIOLOGICAL REPAIR
560121* --Biomedical Sciences
Applied Studies--Radiation Effects--Radiation Effects on Cells--External Source
HAMSTERS
N48210* --Life Sciences--Radiation Effects on Cells-- External Source
SURVIVAL TIME
X RADIATION