Six Mutations Affecting Coat Color in Ranch-Bred Mink

Abstract

Six mutant genes affecting coat color in the mink (Mustela vison) have been reported by various workers. In this paper symbols are proposed for 6 additional genes (sR, Cm, Eb, al, bg, o), and their effects dis cussed. Breeding results indicate that S and sR are alleles, and that Eb and b are linked. The 12 mutant genes can be divided into 2 groups on the basis of their major effects in changing the wild type coat color to the different color phases. The genes F,S,sr,Cm and Eb produce the "dominant" color phases by altering the natural dark pelage to a pattern when singly substituted for their non-mutant alleles. These patterns result from white spotting (royal silver, black cross), a differential between the pigmentation of the underfur and guard hair (ebony), or a combination of both (blufrost, colmira). Homo-zygosity for the genes p, ip, al, b, bg and cH alters the natural dark color to the "recessive" color phases by affecting the pigmentation over the entire pelage. The gene o is the only exception to this rule; it is recessive to its non-mutant allele, but alters the wild type color by producing a pattern as do the dominant genes.