Identification of a mutation that is associated with the saddle tan and black-and-tan phenotypes in Basset Hounds and Pembroke Welsh Corgis

J Hered. 2013 May-Jun;104(3):399-406. doi: 10.1093/jhered/est012. Epub 2013 Mar 21.


The causative mutation for the black-and-tan (a (t) ) phenotype in dogs was previously shown to be a SINE insertion in the 5' region of Agouti Signaling Protein (ASIP). Dogs with the black-and-tan phenotype, as well as dogs with the saddle tan phenotype, genotype as a (t) /_ at this locus. We have identified a 16-bp duplication (g.1875_1890dupCCCCAGGTCAGAGTTT) in an intron of hnRNP associated with lethal yellow (RALY), which segregates with the black-and-tan phenotype in a group of 99 saddle tan and black-and-tan Basset Hounds and Pembroke Welsh Corgis. In these breeds, all dogs with the saddle tan phenotype had RALY genotypes of +/+ or +/dup, whereas dogs with the black-and-tan phenotype were homozygous for the duplication. The presence of an a (y) /_ fawn or e/e red genotype is epistatic to the +/_ saddle tan genotype. Genotypes from 10 wolves and 1 coyote indicated that the saddle tan (+) allele is the ancestral allele, suggesting that black-and-tan is a modification of saddle tan. An additional 95 dogs from breeds that never have the saddle tan phenotype have all three of the possible RALY genotypes. We suggest that a multi-gene interaction involving ASIP, RALY, MC1R, DEFB103, and a yet-unidentified modifier gene is required for expression of saddle tan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agouti Signaling Protein / genetics
  • Alleles
  • Animals
  • Dogs / genetics*
  • Genome-Wide Association Study
  • Hair Color / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Homozygote
  • Mutation*
  • Phenotype


  • Agouti Signaling Protein
  • Heterogeneous-Nuclear Ribonucleoproteins