REGIONAL LOCALIZATION OF THE XRCC4 HUMAN RADIATION REPAIR GENE

To map the XRCC4 human DNA repair gene subchromosomally, a gamma-ray-r esistant human:XR-1 hamster hybrid cell containing fragments of human chromosome 5 and the pSV(2)neo plasmid was lethally irradiated and fus ed with the gamma-ray-sensitive XR-1 mutant cell. After selection for G418 resistance, 2 of a total of 76 hybrids retained wildtype gamma-ra y resistance. FISH analysis of normal human lymphocytes using DNA from the two resistant hybrids as probes produced a common region of hybri dization at 5q13q14, suggesting that the XRCC4 gene is in this region of chromosome 5. The gene was physically localized between D5S427 and D5S401 microsatellite markers and the cytological assignment confirmed using hamster:human hybrids containing known deletions in human chrom osome 5. (C) 1995 Academic Press, Inc.