Black and tan colour pattern

The trait is characterized by the presence of a coat pattern that combines a dark color on the back with a tan coloration on the rest of the body.

Definition

The black and tan coloration pattern is characterized by a dark coat color on the back and tan coloration on the rest of the body. The tan patches expand as the dog grows. The variant responsible for the trait is located in the RALY gene involved in membrane transport processes and cell survival.

Genetic basis

The trait is also known as the "Abs" allele. The presence of one or two copies of the variant results in the expression of the black and tan phenotype, as it is a dominant trait. However, the A, E and K loci may interfere in determining the coloration pattern. It is important to note that there may be other genes or variants that have not yet been identified that may be responsible for the black and tan coat in dogs.

Other relevant information

Dogs with this type of coloration pattern may not show a black coloration of the back, as the eumelanin in that area may be modified. Consequently, the dog in the dorsal area could have a black, brown, blue or lilac color. This color pattern shows a visual parallel to a black saddle on a tan horse, hence this trait is also called black saddle. Breeds commonly showing the trait include Airedale Terrier, Beagle, Corgi, German Shepherd Dog and Yorkshire Terrier.

Bibliography

Dreger DL, Parker HG, Ostrander EA,et al. 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.