Sheriff Of Blackburn
Dun (AKA: Bay Dun or Zebra Dun)
We've received Sheriff's official Coat color test results today!
He is Homozygous for the Agouti gene (A/A), Homozygous for the Dun Dilution gene (D/D) and Heterzygous for the the Red Factor Gene (E/e).
Not a coat color genetics buff, no big deal! Here is a brief summary of what these genes entail:
Agouti Gene: Controls the distribution of black pigment. The dominant allele (A) restricts black pigment to the points of the horse (mane, tail, lower legs and ear rims). As seen, for example, in bays and buckskins.
****A/A= Homozygous Agouti, meaning he can NOT have a black foal or grullo and is highly likely to throw Bays and Buckskins but because he is also Homozygous for the Dun Dilution gene he will throw Bay Duns and Dunskins instead of Bays and Buckskins****
Example of a Dunskin
Dun Gene: The Dun gene is a dilution gene that affects both red and black coat color pigments. The gene is associated with "primitive marking" and has the ability to affect the appearance of all black, bay, or chestnut ("red")-based horses to some degree by lightening the base body coat.
The dark stripe down the middle of the animal's back is the most recognizable marking associated with Dun horses. Other markings include a tail and mane darker than the body coat and usually darker faces and legs.
****D/D= Homozygous Dun, meaning he will ALWAYS produce a Dun Foal (either a bay dun, red dun, dunskin (buckskin dun), dunalino (palomino dun), etc.****
Example of a Dunalino (Palimino Dun)
Red Factor Gene: Horses that are bay, black, grullo, buckskin, black/blue roan, etc. are black pigmented horses that carry at least one copy of the Black Factor (E) allele. The black (E) allele of the extension gene is dominant and causes a black pigmented base both in the heterozygous (Ee) and homozygous (EE) state. A horse that is heterozygous for Red/Black Factor means that it carries one copy of the black allele (E) and one copy of the red allele (e).
****E/e=Heterozygous Extension gene, meaning both black and red factors were detected. He can transmit either E (black) or e (red) to its offspring. The basic color of the horse will be black, bay or brown unless modified by other color modifying genes. Due to his Homozygous Agouti gene he will never throw a brown brown or a black foal. Due to his Homozygous Dun gene, he can and will throw bay duns, Buckskin Duns (dunskins), red duns, palomino duns (dunalinos), Cremello Duns, Perlino Duns, etc.
Example of a Red Dun
Example of a Perlino Dun