title: Mutations induced by X-rays at the HPRT locus in cultured Chinese hamster cells are mostly large deletions.
abstract: We investigated the molecular basis of 19 X-ray-induced HPRT-deficient mutants of V79 Chinese hamster cells with Southern hybridisation techniques. 12 of those mutants suffer from a big deletion (greater than 10 kb) of HPRT DNA sequences. Cytological studies of chromosome preparations of those 12 deletion mutants showed that in at least 3 of these mutants part of the long arm of the X-chromosome was lost. After correction for spontaneous arising mutations we estimate that at least 70-80% of X-ray-induced mutations are caused by large deletions.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002871:Chromosome Banding; D002872:Chromosome Deletion / Q000528:radiation effects*; D006224:Cricetinae; D003412:Cricetulus; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D007621:Karyotyping; D009154:Mutation / Q000528:radiation effects*; D009693:Nucleic Acid Hybridization; D014965:X-Rays
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase