AN INTRASPECIFIC GENE DUPLICATION POLYMORPHISM OF THE URATE OXIDASE GENE OF DROSOPHILA-VIRILIS - A GENETIC AND MOLECULAR ANALYSIS

Nineteen strains of Drosophila virilis from diverse geographic locatio ns were examined by genetic and molecular analyses, revealing (a) 12 s trains with a single copy of the urate oxidase (UO) gene per haploid g enome and (b) 7 strains with a tandem duplication of the UO locus. The D. virilis strains with the UO duplication appear to have identical r estriction maps of this region, implying either a single origin for th e duplication or several similar events occurring at a hot spot. On th e basis of the location of the duplication breakpoints and the restric tion sites flanking these breakpoints, this duplication probably arose through nonhomologous recombination involving either a breakage and r ejoining event or replication slippage. Because documented cases of in traspecific gene duplication polymorphism are rare, the D. virilis UO duplication will be useful in identifying the molecular event giving r ise to a gene duplication.