title: Localization of Chinese hamster dihydrofolate reductase gene to band p23 of chromosome 2.
abstract: It has been shown that gamma irradiation causes extensive deletions at the dihydrofolate reductase (dhfr) locus in Chinese hamster ovary (CHO) cells. We have analyzed seventeen DHFR-negative (DHFR-) mutants of CHO cells for cytogenetic alterations involving the dhfr locus on chromosome 2. Five DHFR- mutants contained the same large deletion [del(2)(p16p23)] in the short arm of chromosome 2. This deletion comprised about 18% of the short arm and was estimated to be 41,000 kb in length. Four other DHFR- mutants contained smaller deletions of about 9200 kb. One of these mutants had a partial deletion of bands 2p22 and 2p23, whereas the others showed deletion of band 2p23. Inversions of chromosome 2 were seen in two other DHFR- mutants. An analysis of the breakpoints involved in these cytogenetic alterations indicates that the hamster dhfr gene resides in band p23 of chromosome number 2.
authors.forename: V L
authors.initials: VL
authors.lastname: Funanage
authors.forename: T T
authors.initials: TT
authors.lastname: Myoda
mesh_terms: D000818:Animals; D002460:Cell Line; D002871:Chromosome Banding; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D005796:Genes; D007621:Karyotyping; D009154:Mutation; D010053:Ovary; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase