title: Determination of the chromosomal site for the human radiosensitive ataxia telangiectasia gene by chromosome transfer.
abstract: The chromosomal localization of the gene which complements radiation hypersensitivity of AT cells was studied by microcell-mediated chromosome transfer. A 6-thioguanine-resistant derivative of an immortalized AT cell line, AT2KYSVTG, was used as a recipient for microcell-mediated chromosome transfer from 4 strains of mouse A9 cells, 3 of which carried a human X/11 recombinant chromosome containing various regions of chromosome 11, while the other carried an intact X chromosome. HAT-resistant microcell hybrids were isolated and examined for their radiosensitivity and chromosome constitution. The microcell hybrid clones obtained from the transfer of an intact X chromosome or an X/11 chromosome bearing the pter----q13 region of chromosome 11 did not show a difference in radiosensitivity from parental AT cells, while those obtained from the transfer of X/11 chromosomes bearing either the p11----qter or the pter----q23 region of chromosome 11 exhibited a marked radioresistance which was comparable to normal human fibroblasts. A HAT-resistant but radiosensitive variant was further obtained from the microcell fusion with an A9 cell strain carrying an X/11 chromosome bearing the 11p11----qter region, in which a deletion at the 11q23 region was found. The results indicate that the gene which complements a radiosensitive phenotype of AT is located at the q23 region of chromosome 11.
authors.affiliation: Radiation Biology Center, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ejima
authors.forename: M
authors.initials: M
authors.lastname: Oshimura
authors.forename: M S
authors.initials: MS
authors.lastname: Sasaki
mesh_terms: D001260:Ataxia Telangiectasia / Q000235:genetics*; D002460:Cell Line; D002871:Chromosome Banding; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D006801:Humans; D007621:Karyotyping; D011836:Radiation Tolerance; D014162:Transfection