Induction and repair of chromosome aberrations in scid cells measured by premature chromosome condensation

Journal Article · Mon Jan 01 00:00:00 EST 1996 · Radiation Research

DOI:https://doi.org/10.2307/3579193· OSTI ID:478296

Evans, J W; Kirchgessner, C U; Brown, J M ^[1]; Liu, X F ^[2]

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1. Stanford Univ. School of Medicine, CA (United States)
2. Chinese Academy of Medical Sciences, Beijing (China)

Severe combined immunodeficient (scid) murine cells, which are defective in both repair of DNA double-strand breaks and V(D)J recombination, are deficient in DNA-dependent protein kinase (DNA-PK), a protein which forms an activated complex with the DNA end-binding Ku proteins (p80 and p70) upon association with damaged DNA. Xrs 5 cells are deficient in the Ku p80 protein and also fail to form an active DNA-PK repair complex. Since both scid and xrs cells are defective in the same protein complex, we compared the kinetics of chromosome repair in scid cells to results published previously for xrs 5 cells. C.B-17 cells, scid cells and scid cells complemented with a single human chromosome 8 were irradiated with 6 Gy and allowed to repair from 0-24 h before fusion to HeLa cells for chromosome condensation. Breaks and dicentrics were visualized by fluorescence in situ hybridization. All cells had the same initial amount of chromosome damage, but scid cells had a slower rate of rejoining, more unrejoined breaks and more dicentrics than C.B-17 and scid cells with human chromosome 8. The scid cells appear to respond differently than xrs 5 cells, despite both cells lacking an essential component of the same DNA repair complex. 40 refs., 6 figs., 3 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 478296
• Journal Information: Radiation Research, Vol. 145, Issue 1; Other Information: PBD: Jan 1996
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
DNA
STRAND BREAKS
GENETIC RADIATION EFFECTS
DNA REPAIR
DELAYED RADIATION EFFECTS
HUMAN CHROMOSOMES
CHROMOSOMAL ABERRATIONS
GENE RECOMBINATION
ANIMAL CELLS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL REPAIR
PHOSPHOTRANSFERASES
PROTEINS
HELA CELLS
DNA HYBRIDIZATION
FLUORESCENCE
DICENTRIC CHROMOSOMES
CESIUM 137
HUMAN CHROMOSOME 8