Tyr^c-m

Coding regions of the Tyrc-m gene are normal, but there is a rearrangement of 5'-upstream regulatory sequences including the locus control region of the Tyr gene. Low-level transcription of tyrosinase and reduced sensitivity to DNAase I was found in clones from light pigmenting melanocytes of homozygotes, while in clones from dark pigmenting cells, tyrosinase transcription was higher (though still less than wild-type) and DNAase sensitivity greater. The upstream rearrangement may separate the Tyr structural gene from cis-acting control elements. (J:997, J:105054)