CHROMOSOMAL LOCALIZATION OF THE HUMAN AHR LOCUS ENCODING THE STRUCTURAL GENE FOR THE AH RECEPTOR TO 7P21-]P15

The AHR locus encodes the structural gene for the Ah receptor, a ligand activated transcription factor that regulates the expression of a number of enzymes involved in the metabolism of chemical carcinogens and that appears to mediate the tumor promoting properties of compounds such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Using polymerase chain reaction (PCR), we amplified exon-10 and intron-D of the AHR gene from human genomic DNA. By using PCR analysis of somatic cell hybrids and fluorescence in situ hybridization of metaphase cells, we localized AHR to human chromosome 7, bands p21 --> p15. This mapping data should prove useful in determining the role that the AHR locus plays in human cancer incidence and in the identification of human populations with altered susceptibilities to the toxic/carcinogenic effects of planar aromatic hydrocarbons.