LOCALIZATION OF THE SQUALENE SYNTHASE GENE (FDFT1) TO HUMAN-CHROMOSOME 8P22-P23.1

Recently, we reported the isolation of a cDNA encoding the human enzym e squalene synthase, the first step of sterol biosynthesis uniquely co mmitted to synthesis of cholesterol (6). As such, it is likely that th is enzyme occupies a critical regulatory position in the synthesis of cholesterol. As part of continuing studies of the role of this gene in cellular metabolism, we undertook the mapping of this gene on the hum an chromosomes. To localize the gene, we have first isolated a yeast a rtificial chromosome (YAC) containing the squalene synthase gene. We t hen used fluorescence in situ hybridization (FISH) with yeast DNA cont aining the YAC to localize the gene to chromosome 8. Assignment to hum an chromosome 8 was confirmed by polymerase chain reaction analysis of a somatic cell hybrid containing human chromosome 8. Use of a somatic cell hybrid regional mapping panel dividing chromosome 8 into several fragments localized the gene to 8p21-pter. Fractional length analysis of the FISH mapping placed the signal generated with this YAC at 8p22 -p23.1. (C) 1994 Academic Press, Inc.