MAPPING OF THE HUMAN GENE FOR INDUCIBLE HEME OXYGENASE TO CHROMOSOME-22Q12

Heme oxygenase is an essential enzyme in heme catabolism that cleaves heme to form biliverdin, releasing carbon monoxide and iron. There are two isozymes of heme oxygenase: heme oxygenase 1 (HO-1) and heme oxyg enase 2, each of which is encoded by a separate gene. It is noteworthy that HO-1 is inducible by various environmental factors, while heme o xygenase 2 is not. Here we have localized the human HO-1 gene to chrom osome 22 by polymerase chain reaction (PCR) analysis of human-hamster somatic cell hybrids. The precise region of the HO-1 locus was then de termined by fluorescence in situ hybridization, revealing that the hum an HO-1 gene is localized to 22q12.