TABLE 3

Epistasis relationships for Agouti, K, and Mc1r

Genotypea
AgoutiK locusMc1rPhenotypebExamplec
at/atk/k+/+Black and tanGerman shepherd dog
at/atk/ke/eYellowAfghan hound
at/atkbr/kbr+/+Black, brindle pointsStaffordshire bull terrier
at/atkbr/kbre/eYellowFrench bulldog
at/atKB/KB+/+BlackBlack Labrador retriever
at/atKB/KBe/eYellowYellow Labrador retriever
ay/ayk/k+/+YellowBoxer
ay/ayk/ke/eYellowAfghan hound
ay/aykbr/kbr+/+BrindleBoxer
ay/aykbr/kbre/eYellowAfghan hound
ay/ayKB/KB+/+BlackGreat Dane
ay/ayKB/KBe/eYellowPoodle
  • a Nomenclature is similar to Table 1, with the R306ter allele of Mc1r indicated as e. For each category, only homozygous genotypes are shown for the sake of simplicity; more genotypes are possible according to dominance relationships for each locus as indicated in Table 1.

  • b These designations refer only to the distribution of eumelanin and pheomelanin and ignore the effects of modifiers that affect spotting and/or pigment quality. For example, black and tan in a cocker spaniel homozygous for the b allele of the Tyrp1 locus would be modified to liver and tan; brindle in a French bulldog carrying an s mutation would appear white with brindle spots.

  • c Examples are based on genotyping studies of dogs from the indicated breeds as described in the text (Newton et al. 2000 or Berryere et al. 2005).