EVOLUTION OF THE TYROSINASE-RELATED GENE (TYRL) IN PRIMATES

Tyrosinase is the major enzyme responsible for the formation of melani n pigment and is found throughout the animal kingdom. In humans, the t yrosinase gene (TYR) maps to the long arm of chromosome 11 at band q14 -->q21, while a tyrosinase related gene (TYRL) maps to the short arm o f chromosome 11 at p11.2-->cen. We and others have found that the TYRL locus contains sequences that are similar to exons IV and V of the au thentic tyrosinase gene but lacks sequences of exons I, II, and III. I n an attempt to understand the evolution of the human tyrosinase gene, we have analyzed TYR and TYRL in primates and have found that exons I V and V of the chimpanzee and gorilla TYR are very similar to the huma n, with the gorilla sequence being more similar than the chimpanzee. W e have also found that the gorilla but not the chimpanzee contains a T YRL locus similar to the human TYRL locus.