Abstract
Purpose: To test the possible involvement of the XRCC2 gene in the control of intra-versus interchromatid rearrangements leading to chromatid breaks in G(2) cells by studying the Colour-switch ratio (CSR) in harlequin-stained Chinese hamster irs1 cells.
Materials and methods: The V79-1 mutant cell lines irs1 (XRCC2 mutation) and irs2 (XRCC8 mutation), two WT V79 lines and GT621-1 (irs1 transfected with the XPLC2 gene) were labelled with BrdU through two cell cycles, irradiated and sampled 1.5 h after exposure. Metaphase spreads were analysed for chromatid break frequency and frequencies of colour-switch (colour-switch between chromatids at the break point) and non-colour-switch breaks, from Which the CSR was calculated.
Results: Chromatid breaks were induced linearly with dose in all lines, and frequencies were elevated in irs1 and irs2 mutant Cell lines when Compared with WT lines. An XRCC2 transfected line (GT621-1) showed full radiosensitivity complementation with respect to frequencies, of chromatid breaks. The CSR was significantly higher in irs1 (13.9%) than in the parental V79-4 (7.5%) or irs2 (4.9%) cells. GT621-1 cells showed partial, but significant complementation with respect to CSR (9.2%).
Conclusions: It is concluded that the significantly higher CSR for the irs1 mutant than for the Wild-type parental V79-4 line indicates the involvement of the XRCC2 gene product in the control of the rearrangement process leading to chromatid breaks.
Original language | English |
---|---|
Pages (from-to) | 859-865 |
Number of pages | 7 |
Journal | International Journal of Radiation Biology |
Volume | 77 |
Publication status | Published - Aug 2001 |
Keywords
- DOUBLE-STRAND BREAKS
- ATAXIA-TELANGIECTASIA CELLS
- SENSITIVE IRS MUTANTS
- HUMAN RAD51 PROTEIN
- IONIZING-RADIATION
- RESTRICTION ENDONUCLEASES
- CHROMOSOMAL-ABERRATIONS
- DNA-SYNTHESIS
- V79 CELLS
- HAMSTER