title: Identification of a mutation that is associated with the saddle tan and black-and-tan phenotypes in Basset Hounds and Pembroke Welsh Corgis.
abstract: 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.
authors.affiliation: Department of Animal and Poultry Science, University of Saskatchewan, 51 Campus Dr., Saskatoon, SK, Canada. dayna.dreger@nih.gov
authors.forename: Dayna L
authors.initials: DL
authors.lastname: Dreger
authors.forename: Heidi G
authors.initials: HG
authors.lastname: Parker
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Ostrander
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Schmutz
mesh_terms: D054366:Agouti Signaling Protein / Q000235:genetics; D000483:Alleles; D000818:Animals; D004285:Dogs / Q000235:genetics*; D055106:Genome-Wide Association Study; D006200:Hair Color / Q000235:genetics; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics; D006720:Homozygote; D009154:Mutation; D010641:Phenotype
chemical_list: D054366:Agouti Signaling Protein; D034441:Heterogeneous-Nuclear Ribonucleoproteins