# Color genetics



## Kyro (Apr 15, 2012)

If you breed an EE horse to an ee horse, you will 100% get a black base horse, since the EE horse has two black genes therefor being homozygous black - will always pass at least one E gene to offspring. Was this what you were asking?

Edited: Wait, I think I misunderstood, let me re-read and think about what you wrote, lol.


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## Kyro (Apr 15, 2012)

Again, like I said, whatever horse you breed with an EE horse, you will get a black base horse. 

If a horse is AA it does not automatically mean he is dominant black as well. He could be EeAA - if he is, bred to a, lets say, chestnut ee mare, he will have a 50/50 chance of throwing a black foal. 

From a genetics site:


> Agouti
> Agouti is often listed just after the red/black factor alleles like these examples: EeAA, EEAA, eeAa, eeaa, EEaa, etc. This is because all horses will have genes representing agouti just as they will all have genes representing red/black factor. Agouti is represented by the alleles (A) and (a). (A) is dominant and (a) is recessive. A horse can be (AA), (Aa), or (aa).
> 
> On black horses (EE) or (Ee), the dominant agouti (A) limits the expression of black to the horse's points. Black points are seen on buckskins and bays and are those black tips on ears, black mane, black tail, and black lower legs. You need recessive agouti genes (aa) to get a true black horse.
> ...


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## kassierae (Jan 1, 2010)

EE will produce a black based horse, but it will be a bay. The resulting foal would be E?A? At the very least. Bay is still black based.
_Posted via Mobile Device_


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## Asimina (Apr 21, 2013)

The 'E' refers to the extension gene, or the 'base color' of the horse. An ee is chestnut based, Ee or EE are black based. The 'A' is a different gene, agouti, that acts on black-based horses. There are a handful of different things that can affect agouti- based on what the horse carries here determines(only on black based horses) if it will be black(recessive agouti- aa), bay(A), wild bay, or seal.

So if a hypothetical horse is EE, and has an agouti factor of AA it will present as a bay horse, and will always pass on the black base and bay to offspring(I believe 'A' is the most dominant in agouti?) But it shouldn't be possible to get a chestnut based foal out of an EE horse.


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## Chiilaa (Aug 12, 2010)

There is a bit of a misnomer that makes this hard to understand sometimes.

Rather than thinking E = black and e = red, try to think more that e = not black. So a horse that is homozygous for e can't produce true black pigment. However, a horse that has an E or two can produce both black AND red. So really when you talk about two base colours, it would be more that there is "no black possible" and "black allowed". This is why various "black based" colours still have red (like bays for example). They don't have a "black" base, they have a black and red base.


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## CAP (Jun 18, 2014)

Ok it's making sense now
I was just always under the assumption that EE will always produce black.. and I realized that AA produces red, but I thought if using a homozygous black with homozygous agouti, you'd have a 50/50 chance of either, but now I understand the only thing that it can produce is a bay or buckskin (my filly has cream) which I guess would be 50/50 genes, but my brain this morning was thinking a little differently.

I've had my heart set on breeding to a stud, that with most horses would be a great chance of giving a grulla foal, but now I found out my one filly is AA, ee, Crc, Dd.. so no chance of that with her.
I just sent away to see what her half sibling test come back as, hopefully something that isn't AA lol..

my fillies are both young so lots of time to find them the perfect stud to compliment them, and by then I may be living in the states so it will open up a lot more possibilities, shipping across the boarder can sometimes be interesting, or I might end up going to the NRHA sale that is happening right about now instead of breeding.. exciting to think about!


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## Bridgertrot (Dec 2, 2011)

Technically AA doesn't "produce red". All horses have the ability to either produce red or black pigment. The more we learn about colors the tougher it seems to be to learn them haha. I'm pretty versed in colors but lately I've been learning some things that once you learn the old way, is hard to wrap your brain around the new findings haha.

"In mammals, there are two types of pigment: red and black. The original coat color of a species, known as the wild color, is typically some combination of both red and black pigment. In horses, the wild color is bay. Cells have the ability to make either of the two pigment types (red or black), and the genes that control them are called “pigment-type switches”.

In horses, like many other mammals, the primary pigment-type switches are Extension and Agouti. The un-mutated (“wild-type”) form of those two genes (“E” and “A”) combine to produce the color we know as bay. The other two basic horse colors, chestnut and black, are the result of mutations to one of those two genes. At Extension, there is a recessive mutation (“e”) that restricts the black pigment to the skin, which means the hair is all-over red. This results in the color we call chestnut. At Agouti, there is a recessive mutation (“a”) that removes all restriction from black pigment, so if the horse can have black hair—that is, if he is not chestnut—he will be all-over black. This is the color we call black. Additionally, it is believed that there may be other variants (alleles) at Agouti that restrict black pigment more or less strongly than either bay (“A”) or black (“a”). These are proposed to be responsible for colors like seal brown and wild bay."

That's a snippet from the Equine Tapestry blog. 

If you really want to rack your brain try reading this: Bay is not a modifier |

I'm still trying to make sense of this new stuff myself ha!


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## CAP (Jun 18, 2014)

well I got the results back for my other filly, she is Ee AA N/Cr D/N.. 
slightly different from her sibling. 



and the filly I talked about previously. ee AA N/Cr D/N


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## Yogiwick (Sep 30, 2013)

Think of A as "_allows_ red." So if your black horse has A then it will have red "allowed" making it bay/brown instead of black.

You posted the same genetics for the two. Such lovely mares


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## CAP (Jun 18, 2014)

Yogiwick said:


> Think of A as "_allows_ red." So if your black horse has A then it will have red "allowed" making it bay/brown instead of black.
> 
> You posted the same genetics for the two. Such lovely mares


Opps sorry, my dunalino is ee AA N/Cr D/N, I couldn't edit my earlier post.


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## Yogiwick (Sep 30, 2013)

Pretty similar though!


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## NdAppy (Apr 8, 2009)

CAP said:


> well I got the results back for my other filly, she is Ee AA N/Cr D/N..
> slightly different from her sibling.
> 
> 
> ...


Just quoting this because the forum changes capitalization. the second is "ee" not Ee.


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## NdAppy (Apr 8, 2009)

CAP said:


> Opps sorry, my dunalino is ee AA N/Cr D/N, I couldn't edit my earlier post.


Ahh didn't see this post. The forum will automatically capitalize some things. That happens to be one of them


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## trytous123 (Dec 27, 2014)

I have a buckskin mare. What color stud would I use to get a buckskin foal? Please help


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## SunnyDraco (Dec 8, 2011)

trytous123 said:


> I have a buckskin mare. What color stud would I use to get a buckskin foal? Please help


Your mare can produce buckskin, she possesses all the ingredients for buckskin, but depending on the black and agouti will effect your chances of getting another buckskin. 

When breeding a buckskin to produce another buckskin, the best you can do is get a 50% chance of a buckskin foal. 

Without knowing your mare's black and agouti status... If you bred her to a bay stallion who is tested EE AA (homozygous black and agouti), you would have 50% chance of buckskin and 50% chance bay. If you bred your mare to a perlino stallion who is tested EE AA CrCr, you would have a 50% chance buckskin and a 50% chance perlino.


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