Coat Colour A-Locus (Agouti) – Dog

Coat colour in dogs is controlled by a wide range of different genes working together. These genes are often referred to as ‘loci’. The Agouti locus (A-locus) is a genetic location in dogs that is regulating the distribution and balance of the two main pigments in the coat; eumelanin (black or brown pigment) and phaeomelanin (red or yellow pigment). This locus is associated with the Agouti Signaling Protein (ASIP) gene, which influences how and where these pigments are deposited in the hair.

The Agouti protein works by interacting with the melanocortin 1 receptor (MC1R) on melanocytes (cells that produce pigment). When activated, ASIP switches the production of dark eumelanin to light phaeomelanin, leading to the characteristic coat patterns seen in many dog breeds. This only influences animals that can produce dark pigmentation, which is dependend on the E-locus.

The Agouti locus plays a crucial role in producing various coat patterns, contributing to the diversity of coat colors and patterns observed in dog breeds. Within this test four patterns can be distinguished: Agouti (banded hairs), Solid Black (black hairs), Tan Points (light and dark areas), Yellow/Fawn (mainly light hairs).

Coat colour is an intricate trait that involves a combination of multiple different genes. Testing for a range of different loci will give the most complete prediction of a dog's coat colour genetics.

In this test, results are reported using the traditional phenotype-based A-locus notation. Some laboratories use a newer genotype-based reporting system. Both systems describe the same gene, but the way results are presented differs, so comparison between laboratories may require additional interpretation.

Pubmed ID:

Year published: 2005

Omia ID: 201

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