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 ligan d activated transcription factor that regulates the expression of a nu mber of enzymes involved in the metabolism of chemical carcinogens and that appears to mediate the tumor promoting properties of compounds s uch as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Using polymerase ch ain 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 localize d AHR to human chromosome 7, bands p21 --> p15. This mapping data shou ld prove useful in determining the role that the AHR locus plays in hu man cancer incidence and in the identification of human populations wi th altered susceptibilities to the toxic/carcinogenic effects of plana r aromatic hydrocarbons.