Assignment of d-amino-acid oxidase gene to a human and a mouse chromosome

Summary. A part of d-amino-acid oxidase gene was amplified in the human and mouse by polymerase chain reaction. The amplified fragments were ligated to plasmids and then cloned. The plasmids containing the parts of d-amino-acid oxidase gene were biotinylated and hybridized to human and mouse metaphase chromosomes. The chromosomal slides were treated with fluorescein isothiocyanate (FITC)-conjugated avidin. The hybridized signals were amplified with biotinylated anti-avidin antibody and FITC-avidin. The chromosomes were counter-stained with diamidino-phenylindole for assignment of the signal to a specific band. Using this fluorescence in situ hybridization (FISH), d-amino-acid oxidase gene was assigned to human chromosome 12q23–24.1 and mouse chromosome 5E3-F. Since these regions are syntenic between human and mouse, the present results indicate that the locus for this enzyme has been conserved through evolution. Received July 11, 2000 Accepted November 10, 2000