1992 Articles

Assignment of the Human TYRP (brown) Locus to Chromosome Region 9p23 by Nonradioactive in Situ Hybridization

Vundavalli, Murty V.; Bouchard, Brigitte; Mathew, Susan; Vijayasaradhi, Setaluri; Houghton, Alan

The TYRP (brown) locus determines pigmentation and coat color in the mouse. The human homolog of the TYRP locus has been recently identified and shown to encode a 75-KDA transmembrane melanosomal glycoprotein called gp75. The gp 75 glycoprotein is homologous to tyrosinase, an enzyme in evolved in the synthesis of melanin, forming a family of tyrosinase-related proteins. A genomic clone of human gp75 was used to map the human TYRP locus to chromosome 9, region 9p23, by nonradioactive fluorescent in situ hybridization. Specificity of hybridization was tested with a genomic fragment of hu- man tyrosinase that mapped to a distinct site on 1lq2 1. The 9p region has been reported to be nonrandomly altered in human melanoma, suggesting a role for the region near the TYRP locus in melanocyte transformation.