A horse with the "brown" gene.
Genetics[]
Genetics are passed down from the parents to the offspring. Genetics can decide a horse's color, temperment, and success. In the model horse world, collectors often give their models "pedigrees" and with pedigrees come genetics. These genetics being added to the model's pedigree adds to the realism of the pedigree and allows collectors to charge more money for their pedigrees. Collectors focus on color genetics because any other genetics being added would become to complex and difficult to understand. These genetics will be pass down to the model's "offspring" when it is put out to "stud" or "bred". They decide what color, markings, and patterns the offspring can have with that model.
Base Colors[]
Here is a list of the base colors in the horse world. This goes for real horses and model horses. These colors are the base colors in genetics.
A copper-red chestnut horse.
Black is dominant to chestnut and chestnut is recessive. This means a horse carrying two black genes (EE) will be homozygous black. A horse carrying on black gene and one chestnut gene (Ee) would also be black, but heterozygous. A horse carrying two chestnut genes (ee) will always be homozygous. If two hetrozygous black horses bred together (Ee + Ee), they have a 1 out of 4 chance of producing a homozygous black (EE), a 2 out of 4 chance of producing a heterozygous black (Ee), and a 1 out of 4 chance of a chestnut (ee). Two chesnuts (ee + ee) can only produce a chestnut.
- Chestnuts (e): There is a varity of chestnut shades a horse can be. Chesnut is normally considered a redish brown color, but it can range from coppery red to dark liver. Darker chestnuts can appear to be almost black and can be difficult to tell apart from actual black horses. Affirmed, the 1978 Triple Crown Winner was a golden chestnut. There is also liver chestnut, red chestnut, black chestnut, and chestnuts with flaxen manes and tails.
- Blacks (E): Black horses surprisingly come in varity too. There is blue-black, sun-faded black, and non-fading black. Black horses can look so faded sometimes that they actually appear to be bay or even liver chestnut. Blacks can have faded tails also.
A bay 3/4 Arabian mare grazing.
Dilution Genes[]
Dilution genes act on the base colors to produce many of the horse colors we see today. They all dilute the main body color, but do not always dilute the color in the legs, mane, and tail. These genes are Agouti, Cream, Dun, Silver Dapple, Champagne, and Pearl.
- Agouti: The agouti gene is a dominant gene, so if a horse carries it, it will be shown. Agouti causes the most basic dilution color, Bay. The agouti gene dilutes black to create bay. Technically agouti isn't not a seperate gene, but part of the black gene called an allele. There are three forms of agouti. Agouti (A) means the horse is bay. Non-agouti (a) means the horse remains black. Brown (At) is often confused with dark bay, but it is genetically different from bay. Settle Slew had the brown gene. There is also wild type bay which is thought to be created by old breeds like Fjords and Przewalski's Horses. In a wild bay, the black on the legs is restricted to the joint areas.
- Cream: The cream gene can modify any color gene unlike the agouti gene. It is most commonly seen in chestnuts and bays however. The cream gene is considered an incomplete dominant. This means it is always expressed when persent, but it doesn't act like the heterozygous (1 copy of gene) and homozygous (2 copies of gene) request. A horse with one cream gene with be diluted and a horse with two creme genes will be double diluted in this case. Double diluted horses always have blue eyes. The creme gene can only effect black hairs in its double gene state, not single gene state. Colors created with the creme gene include palomino, buckskin, and smoky black. If two creme genes are present it can create cremello, perlino, and smoky cream.
- Dun: The dun gene is a complete dilution gene. This means the heterozygous duns and homozygous duns look the same. Duns normally have a dorsal stripe down the back, leg barring (zebra stripes) on their legs, and cobwebbing on the face. These are known as dun factors. The dun gene only dilutes the body color, not the legs, mane, or tail. There are Red Duns (chestnut and dun mix), Bay Duns (bay and dun mix), and Black Duns (or Grulla) (black and dun mix).
- Silver Dapple: The silver dapple gene can only affect horses with the black pigment, not chestnut. The silver dapple gene affects the body and the legs slighty by changing the black pigment to a chocolate color. The horse's mane and tail will also become pale and flaxen. This is mainly found in Mustangs, Shetland Ponies, Icelandic Ponies, and Rocky Mountain Horses.
- Champagne: The champagne gene is similar to the dun gene in the way that it works. Champagne is a dominant dilution gene. If a horse carries this gene, he will be champagne. Champagne and black is called "Classic", with bay it is "Amber", with chestnut it is "Gold", and with brown it is "Sable". Champagne be combined with the creme gene in some cases and this creates "Ivory". Horses with the champagne gene normally are born with light pink skin which will freckle with age. They are born with blue eyes that will turn hazel as they age. Champagne genes can also have metallic-like coats. Common breeds like Tennessee Walking Horses, Quarter Horses, American Saddlebreds, and Missouri Foxtrotters often carry this gene.