title: Gene dosage mutants at adenine phosphoribosyltransferase locus induced by colcemid in Chinese hamster V79-AP4 cells.
abstract: Pseudodiploid Chinese hamster V79-AP4 cells, functionally diploid at the adenine phosphoribosyltransferase (aprt) locus, were treated with colcemid, a well-known aneuploidizing agent, under various experimental conditions. Aneuploid and tetraploid cells and variants resistant to 10 micrograms/ml of 2,6-diaminopurine (DAP), which selects for presumptive aprt+/- heterozygotes in the untreated cells, were induced. Many of the induced variants were hypotetraploid with three (rather than four) chromosomes carrying the aprt gene. Dot-blot and Southern analysis of the DNA of these clones confirmed that they had three copies of the aprt gene. Their APRT specific enzymatic activity was 60-80% of that of wild-type V79-AP4. The results of these and other experiments suggest that in these variants resistance to DAP is due to an altered aprt gene dosage and point to a possible genetic effect of colcemid and other aneuploidizing agents in somatic mammalian cells.
authors.affiliation: Istituto di Mutagenesi e Differenziamento CNR, Pisa, Italy.
authors.forename: C M
authors.initials: CM
authors.lastname: Colella
authors.forename: S
authors.initials: S
authors.lastname: Simi
authors.forename: G
authors.initials: G
authors.lastname: Rainaldi
authors.forename: T
authors.initials: T
authors.lastname: van Boxel
authors.forename: G
authors.initials: G
authors.lastname: Della Valle
authors.forename: A F
authors.initials: AF
authors.lastname: Peverali
authors.forename: D
authors.initials: D
authors.lastname: Talarico
authors.forename: T
authors.initials: T
authors.lastname: Mariani
authors.forename: A
authors.initials: A
authors.lastname: Piras
authors.forename: M
authors.initials: M
authors.lastname: Simili
mesh_terms: D015075:2-Aminopurine / Q000031:analogs & derivatives / Q000494:pharmacology; D000228:Adenine Phosphoribosyltransferase / Q000235:genetics*; D000782:Aneuploidy / Q000187:drug effects; D000818:Animals; D002874:Chromosome Mapping; D006224:Cricetinae; D003412:Cricetulus; D003703:Demecolcine / Q000494:pharmacology*; D005796:Genes; D009154:Mutation / Q000187:drug effects*; D010430:Pentosyltransferases / Q000235:genetics*; D011003:Ploidies
chemical_list: D015075:2-Aminopurine; C007300:2,6-diaminopurine; D010430:Pentosyltransferases; D000228:Adenine Phosphoribosyltransferase; D003703:Demecolcine