Localization to chromosome 7q36.1 of the human XRCC2 gene, determining sensitivity to DNA-damaging agents.
The identification of genes controlling cellular response to DNA damage is of considerable importance, and cell lines showing hypersensitivity to DNA-damaging agents can be used as vehicles to map and clone these genes. In this study the hamster cell line irs1, showing hypersensitivity to a number of different DNA-damaging agents, was fused to normal human cells to complement the defect. The resultant hybrids were analysed by Alu-PCR, chromosome painting, and with DNA markers to map the complementing gene (named XRCC2) to a specific chromosomal region. These hybrids showed correction of sensitivity to both X-rays and to mitomycin-C, and contained human chromosome 7, often as their only human component. Hybrids showing unstable retention of human chromosomes were sub-cloned to show that loss of chromosome 7 and loss of resistance to mitomycin-C occurred concordantly. Two separate hybrids were found to have a smaller piece of chromosome 7, and specific DNA probes and microsatellite markers defined this as a contiguous region at 7q35-36. Hybrid irradiation-fusion methods were used to further reduce the size of the complementing genomic region and to localize the gene to an approximately 3-5 Mb region at 7q36.1.
Thacker
J
J
MRC Radiobiology Unit, Chilton, Didcot, Oxon, UK.
Tambini
C E
CE
Simpson
P J
PJ
Tsui
L C
LC
Scherer
S W
SW
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002897:Chromosomes, Human, Pair 7; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D017931:DNA Primers; D005816:Genetic Complementation Test; D006801:Humans; D006822:Hybrid Cells; D016685:Mitomycin / Q000633:toxicity*; D008969:Molecular Sequence Data; D014965:X-Rays
D017931:DNA Primers; D016685:Mitomycin; D004247:DNA