Tawny: A novel light coat color mutation found in a wild population of Musmusculus molossinus, a new allele at the melanocortin 1 receptor (Mc1r) locus

We found a new coat color mutant in a population of Japanese wild mice (Mus musculus molossinus) and called the trait tawny. The tawny mutant is chara cterized by a light yellowish brown coat color. The tawny hair has a so-cal led agouti pattern, but the yellow band is greatly lengthened. There are no differences between the tawny and wildtype hairs in size and the number of melanosomes. Genetic analyses revealed that the tawny trait is an autosoma l recessive and its gene is located in the distal region on Chromosome 8 be tween the microsatellite markers DgMit87 and DBMit122. An allelism test ind icated the tawny mutant gene to be a new allele at the Mc1r locus and domin ant to the recessive yellow (Mc1r(e)). The proposed gene symbol for the taw ny is Mc1r(taw).