TABLE 1

Phenotype–genotype relationships for Agouti, K, and Mc1r

Possible genotypes based on this worka
Common namePhenotype and breed exampleHistorical names (symbols)AgoutiK locusMc1r
Dominant black or “self-colored”Uniformly black, can be modified to brown or by white spotting: Newfoundland, black or brown Labrador retrieverDominant black, Agouti-Self (AS)ay/a, ay/at, ay/aKB/KB, KB/ky, KB/kbr+/+, +/R306ter
Recessive yellowUniformly red–yellow, can be modified to pale yellow or cream: yellow Labrador retriever, Irish setter, Samoyedrecessive yellow, extension (e)ay, at, a (all combinations)KB, kbr, ky, (all combinations)R306ter/R306ter
FawnRed–tan, can be dark tinged: Great Dane, fawn (i.e., yellow) boxerdominant yellow, golden sable (ay)ay/a, ay/at, ay/aky/ky+/+, +/R306ter
Black and tanDobermann pinschertan points (at)at/a, at/aky/ky+/+, +/R306ter
BrindleBlack- and yellow-colored stripes: brindle French bulldog, brindle boxerbrindle, partial extension (ebr)ay/a, ay/at, ay/akbr/kbr, kbr/ky+/+, +/R306ter
Recessive blackUniformly black: black German shepherd dogrecessive black(a)a/aKB, kbr, ky (all combinations)+/+, +/R306ter
  • Explanations and references for names and symbols are given in the text.

  • a Possible genotypes according to epistasis relationships as described in the text and in Table 3. Only three Agouti alleles are considered for the sake of simplicity; the aW allele would behave identically to the at allele. Also, the “+” allele at Mc1r is used to designate any Mc1r allele other than R306ter (also known as recessive yellow or e).