Agouti (Bay/Black)

Quick Summary

The agouti gene controls the distribution of black pigment, and determines whether a horse will have a bay or black base coat color.

Example of a horse with bay coat color
Horse with bay coat color

Phenotype: The agouti gene controls the distribution of black pigment, and determines whether a horse will have a bay or black base coat color.

Mode of Inheritance: Autosomal dominant

Alleles: A = Dominant agouti allele (responsible for bay), a = Recessive agouti allele (causes black)

Breeds appropriate for testing: All breeds

Explanation of Results:

  • If black pigment is present, horses with A/A genotype have black pigment restricted to the points. They will transmit the dominant agouti allele to all of their offspring.
  • If black pigment is present, horses with A/a genotype have black pigment restricted to the points. They will transmit the dominant agouti allele to 50% of offspring and the recessive agouti allele to 50% of offspring.
  • Horses with a/a genotype will have black pigment distributed uniformly over the body and will transmit the recessive agouti allele to all of their offspring.
Price

$25 one test per animal

Panels Available
Additional Details

Black horse
Horse with black coat color

Agouti controls the distribution of black pigment, with two known alleles.

The mutation causing an all black phenotype is an 11 base pair deletion in exon 2 of the gene agouti-signaling protein (abbreviated as ASIP but also commonly called agouti for short).  This deletion is notated as (c.191_201del). This mutation is considered to be a loss of function mutation, meaning that the recessive (a) allele causes the resulting protein to be non functional. The dominant agouti allele (A) functions normally to restrict black pigment to the points of the horse, and the recessive (a) allele is unable to restrict pigment to the points of the horse and results in a uniform distribution of black pigment across the body. Breeders interested in producing black horses need to have breeding stock carrying the a allele, in addition to the E allele of the Extension gene.

Testing for the agouti gene allows breeders to identify animals that carry or have two copies of the recessive (a) allele and can transmit this allele to produce offspring with a black base coat.

Turnaround Time
2-6 business days
Type of Sample

Species

Breed

Crossbred Unknown Akhal Teke American Sport Horse American Sport Pony American Warmblood Andadura Andalusian Appalachian Singlefoot Appaloosa Appendix Arabian Arriador Australian Stock Horse Azteca Baden-Wurttemberg Barockpinto Baroque Pinto Bashkir Curly Bavarian Belgian Belgian Sport Horse Belgian Warmblood Brandenburg British Sport Horse Bucking Horse Burchell's Zebra Caballo Deportivo la Silla Camarillo White Canadian Horse Canadian Warmblood Caspian Horse Chapman's Zebra Chilean Horse Cleveland Bay Clydesdale Connemara Pony Continental Warmblood Costa Rican Paso Horse Cream Draft Criollo Curly Dales Pony Danish Warmblood Deutsches Reitpony Deutsches Sportpferd Draft Cross Dutch Harness Horse Dutch Warmblood Exmoor Pony Falabella Faux Friesian Fell Pony Finnhorse Fire Friesian Frederiksborg French Warmblood "Selle Francais" Friesian Friesian Cross Friesian Sporthorse Georgian Grande German Riding Pony Gotland Pony Grevy's Zebra Gypsian Gypsy Cob Gypsy Vanner Hackney Horse Hackney Pony Haflinger Half Andalusian Half Arabian Half-Marchador Hanoverian Hartmann's Zebra Heck Tarpan Hessen Hibrido Holsteiner Iberian Warmblood Iceland Pony Icelandic Horse Imperial Heritage Horse Sporthorse International Sport Pony Irish Draught Irish Hunter Kallblodstravare Kentucky Mountain Horse Kerry Bog Pony Kiang Kiger Mustang Knabstrupper Kulan Latvian Warmblood Lipizzaner Lusitano Mangalarga Mangalarga Marchador Mexican Sport Horse Miniature Horse Missouri Fox Trotter Mongolian Domestic Horse Morab Morgan Horse Moriesian Moroccan Barb Mountain Pleasure Horse Mule Mustang National Show Horse Newfoundland Pony Nokota North American Trakehner Norwegian Fjord Horse Oldenburg Onager Other Paint Horse Paso Fino Percheron Performance Horse Int'l Peruvian Paso Pinto Polish Warmblood Pony of the Americas Przewalski Pura Raza Española Quarter Horse Racking Horse Rheinland Rheinland Pfaltz-Saar Rocky Mountain Horse Russian Orloff Russian Warmblood Saddlebred Scottish Highland Pony Shetland Pony Shire Shire Crossbred Sillo Argentino Single-Footing Horse Spanish Barb Spanish Heritage Horse Spanish Mustang Spotted Saddle Horse Standardbred Suffolk Punch Swedish Warmblood Tarpan Tennessee Walking Horse Thailand Pony Thoroughbred Trakehner Trocha Trocha y Galope Trote y Galope Turbo Friesian Uruguayan Criollo Virginia Warmblood Warlander Welsh Pony Welsh Pony Weser Ems Ponies Westfalen Wild Horse Zangersheide British Spotted Pony Noriker Ardennes Norwegian Nordland Breton Comtois New Forest Pony Cob Normand Rhenish German Coldblood South German Coldblood Saxon-Thuringian Coldblood
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Type of Test

Results Reported As
Test Result Agouti
A/A 2 copies of agouti present. If present, black pigment is restricted to the points.
A/a

1 copy of agouti. If present, black pigment is restricted to the points.

a/a

If present, black pigment is distributed uniformly over the body.

References

Rieder, S., Taourit, S., Mariat, D., Langlois, B., & Guérin, G. (2001). Mutations in the agouti (ASIP), the extension (MC1R), and the brown (TYRP1) loci and their association to coat color phenotypes in horses (Equus caballus). Mammalian Genome, 12(6), 450-455. doi: 10.1007/s003350020017