title: The role of acentric chromosome fragments in gene amplification.
abstract: We assessed the role of acentric chromosome fragments in gene amplification by using cell fusion techniques to introduce the fragmented chromosomes of a donor Chinese hamster ovary (CHO) cell line that contained the dihydrofolate reductase (dhfr) gene(s) into a CHO cell line deficient for dhfr. Chromosome fragments were successfully integrated into cells at a frequency of approximately 3%. Methotrexate-resistant variants arose much more frequently in two cell lines derived from these successful cell fusions than in wild-type CHO cells. The hybrid cell lines also amplified their dhfr genes more readily than did the CHO cell line used as dhfr donor.
mesh_terms: D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D002875:Chromosomes / Q000648:ultrastructure*; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D005784:Gene Amplification; D007621:Karyotyping; D008727:Methotrexate / Q000494:pharmacology; D013762:Tetrahydrofolate Dehydrogenase / Q000172:deficiency / Q000235:genetics
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate