Monday, September 24, 2012

Extension AKA Black or Red

Extension is the gene that controls whether a horse is black based (E) or red based (e), the only two colors that are true base colors. Every other horse color is a caused by a modifier or dilution. As I said in my last post black (E) is dominant over red (e). A black based horses genetic composition will be either Ee or EE, and a red based horses genetic composition will always be ee.

Here are some examples of black horses
This is Aloha. He is a black Mecklenburg stallion, standing at Gray Fox Farms. His genetic composition is Ee.

This is Redwine he is a Hannoverian stallion, who also stands at Gray Fox Farms, and also has a genetic composition of Ee.

This is Zorro. A homozygous black (EE) Friesian Stallion standing at Mon Cheval.

This is Sjoerd, another homozygous black (EE) Friesian stallion, standing at Three Day Ranch.

And here are the red based horses.
This is AC's Painted Lace. She, like all red bases is ee. (Photo copyright ACCPhotography)

This is the grand prix show jumping stallion Baloubet du Rouet. He of course is ee.

This is Couleur Rubin, a chestnut (ee) Oldenburg stallion

This is Don Schufro, a dark or liver chestnut stallion

Within the next week or so, I will be doing at least one other post on the Agouti modifier, and hopefully the Cream dilution as well!! See you then!

1 comment:

Maryh Holland said...

My Appaloosa mare (With both black and red in her roan coat) was bred to a cremello Appaloosa stallion. I hoped to get a buckskin or palomino. The colt was born black with pewter colored sides. His first shedding turned him bright red, no black on his legs, and he kept the black mane and tail. Next he shedded out and became metallic bronze with faint tiger stripes. He turned bright red again for his first winter. His yearling Springtime coat was....Purple!! In autumn he became dark chocolate (like semi-sweet Hershey's). I sold him then so I have no idea what color he is now or if he still changes. The Color Genetics lab at UC Davis tested him for free after I sent them pictures. He has the LP gene as well as a creme gene, a dun gene, a red gene and a black gene. He has no agouti gene. I have pics of him as a newborn, the bronze color and purple as well as the dark chocolate. Somehow didn't photograph him when he was bright red with his black mane and tail.