Genetics Simplified

This is a list of the basic horse genetics, along with a short summary of what they do and how they act. This does not include body markings.



Black

EE or Ee: Dog forms black pigment in skin and hair.
ee: Dog is chestnut.


Agouti

AA or Aa: Dog is a Bay, black hair shows only in points pattern (usually mane, tail, legs, sometimes tips of ears).
aa: No agouti gene. If Dog has E allele, then horse will be uniformly black.


Chestnut

ee/aa(AA/Aa): Dog is chestnut.


Cream

nCr: Single dilution factor. This gene creates buckskins, palominos, and Smoky Blacks.
CrCr: Double dilution factor. This gene creates Cremellos and Perlinos.


Champagne

ChCh/nCh: Champagne gene. This gene gives a golden or bronze cast to the dog's coat color. It is a dilution.


Pearl

prl/prl: Pearl. Pearl creates a uniform pale color on the dog's body. It is a dominate recessive gene.
PRLPRL/PRLprl: No pearl.


Dun

DD/Dd: Dog shows a diluted body color to pinkish-red, yellow-red, yellow or mouse gray and has dark points including dorsal stripe, shoulder stripe and leg barring.
dd: No dun.


Silver

ZZ/nZ: Dilution in black pigment. It also turns the dog's neck ruff and fur on the throat white/silver.
zz: No silver.


Grey

GG/Gg: Dog will grey with age. Greys can range from "white" to dark grey and can even dapple.
gg: No grey.


Roan

RnRn/nRn: Roan pattern of white hair mixed in with base color. The head and legs are left as their original color.
rnrn: No roan.



You can combine these genetics to get a certain coat color. For example:


Bay Dun: Ee/Aa/Dd
Red Dun: ee/AA/DD
Grullo: EE/aa/DD
Silver Black: Ee/aa/nZ
Double Black Pearl: EE/aa/prlprl
Apricot: ee/Aa/prlprl
Cremello: ee/AA/CrCr
Buckskin: Ee/AA/nCr
(Grey) Buckskin: Ee/Aa/nCr/GG
(Grey) Black: EE/aa/Gg
Palomino Roan: ee/AA/nCr/RnRn
Silver bay Roan: EE/AA/ZZ/Rnrn