Expression of tyrosinase gene in amelanotic mutant mice

In order to study the molecular aspects of albinism, we analyzed the expression of tyrosinase gene in some amelanotic mutant mice by Northern blotting using mouse tyrosinase cDNA as a probe. It hybridized with a species of 2.1 kilobase RNA prepared from the skin of wild-type mice and two albino strains in the same quantity. In black-eyed white mouse, however, no RNA transcript encoding tyrosinase was detected. Our results suggest that these albinism is due to a point mutation in the structural region of the tyrosinase gene, not to a deficiency of tyrosinase gene expression and that the black-eyed white mouse has a deficiency in the gene expression possibly related to melanocyte differentiation.