Coat Colour A-Locus (Agouti) – Horse
Code: P907
Short description
The Coat Colour A-Locus, or agouti signaling protein (ASIP) gene, controls the distribution of black pigment in horses.
General information
The Coat Colour A-Locus, or agouti signaling protein (ASIP) gene, controls the distribution of black pigment in horses. ASIP interacts with the MC1R gene, which is associated with the production and balance of black and red pigments. This mutation is classified as a loss-of-function mutation, meaning the recessive allele produces a nonfunctional protein.
Genetic testing for the agouti gene helps breeders identify horses that carry or possess two copies of the recessive allele, which can result in offspring with a black base coat. However, for a horse to be fully black, it must also carry at least one dominant allele of the E-locus. Testing for the E-locus is available with test code P904.
Specifications
| Breeds | All Breeds |
|---|---|
| Gene | ASIP |
| Chromosome | 22 |
| Mutation | c.191_201del |
| Organ | Integumentary System |
| Specimen | Hair, Blood EDTA, Blood Heparin, Semen, Tissue |
| Mode of Inheritance | Autosomal Recessive |
| Also known as | A-Locus |
Clinical features
The agouti gene plays a key role in determining coat colour. The dominant agouti allele restricts black pigment to the horse’s points (mane, tail, and lower legs), leading to a brown body. The recessive allele does not restrict the black pigment, resulting in a black coat.
Additional information
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 horse's coat colour genetics.
Specific breeds are undefined.
References
Pubmed ID: 11353392
Year published: 2001
Omia ID: 201
Omia variant ID:
Turnaround information
- 15 working days