Question About Homozygous Black Horses

[StarRidgeAcres]

Update on page 2. I was mistaken!

Can someone explain how it is possible that a horse that is homozygous for black (EE) can be from one red parent? Does it mean the black-based parent was homozygous for black and that's how it happened?

Ugggghhhhh! Sometimes this color stuff seems like rocket science to me!

 

[targetsmom]

I don't think it IS possible for a horse to be homozygous for black (EE) if they had a red parent (who would be ee and therefore not able to contribute the "E" needed). Could it be that the "red" parent was really a silver bay?? Or something else I can't think of???

 

[StarRidgeAcres]

Holy #*$&% Mary!!!

That's what I was thinking. This is one of those moments where you wake up in bed in the middle of the night and think "something's not right here!"

I'm thinking I've got a mystery on my hands....

 

[rabbitsfizz]

As Black is dominant to Red, Black "shows" when it is present.

Thus Red X Black = (visually ) Black horse.

In order to get Homozygous Black, only Black can actually be present, but, as each parent gives only half the genetics to each foal a Red X Black horse, bred to a Red X Black horse can result in a Black X Black foal, which is Homozygous for Black.

Does that help??

Oops, this may not have been your question!!!

A H/Z Black has to have two visually Black parents...is that your question???

 

[StarRidgeAcres]

As Black is dominant to Red, Black "shows" when it is present.Thus Red X Black = (visually ) Black horse.

In order to get Homozygous Black, only Black can actually be present, but, as each parent gives only half the genetics to each foal a Red X Black horse, bred to a Red X Black horse can result in a Black X Black foal, which is Homozygous for Black.

Does that help??

Rabbit, speak very slowly and use very small words!

I think you are saying that is it possible for a visually red horse (say palomino) to being carrying black also. So when that palomino is bred to a buckskin (which obviously is carrying black) the result COULD be a homozygous black foal. Is that what you are saying?

ETA: When I use the animal genetics color calculator, it does NOT give EE as one of the options when I do the cross of the sire and dam, with leaving all the modifying factors as "unknown."

 

[REO]

I've had plenty of Red X black = Red foals. When a horse is RED (not silver bay etc) it is homozygous for red. (so I understand) And a black horse can be black and still have a copy of black and a copy of red. So in THAT case, a red horse bred to a black horse that also carries red (though it is black) can result in a red foal.

The only time a black will over come a truely red horse 100% is if it is homozygous for black.

Isn't that right Jane?

 

[REO]

Is it truely a palomino? Is it possible that the palomino carries silver?

Silver is "black". Some homozygous for black horses have thrown silvers and some silvers have thrown homozygous for blacks.

I'm not a color expert (LOL) but if a palomino has indeed had a homozygous for black foal, then that palomino (IMO) carries silver in some form (or is even a silver bay somehow?)

 

[txminipinto]

No, it's not possible so one of the parents is not "red". You have to have EE x EE or Ee x Ee for chance of a homozygous black. A Bay is a black horse, not a red one.

 

[Becky]

A H/Z Black has to have two visually Black parents...is that your question???

Or any black based parents. Not only black; but silver, bay, buckskin, etc.

I have a homozygous for black bay stallion.

 

[targetsmom]

I have a homozygous for black GRAY mare!!! She is actually a silver bay frame overo, with the gray gene. That was how I knew that her foal - who LOOKED chestnut when born- could not be. (He is also a silver bay).

 

[cretahillsgal]

It is impossible for you have a true palomino (ee) as the sire of a homozygous black (EE) foal.

I would first wonder if the palomino is really a silver buckskin or silver black. Then I would begin to wonder if the palomino is really the sire of the foal.

 

[targetsmom]

Is the EE horse parentage qualified? If so, then I would guess that the colors were wrong on the papers.

 

[StarRidgeAcres]

Ok folks, here's the good news....

It's two-fold!

First, I was MISTAKEN!!! Both the sire and dam are buckskins, one is NOT palomino, therefore it is possible for the foal to be EE. Whew!

Second, I learned a TON from this thread!!!

So thank you for putting up with my ignorance and my misunderstanding.

 

[vickie gee]

You are not ignorant! Genetics are fascinating. I developed a passion for genetics when my 10th grade biology teacher taught genetics to us out of a college book! Just remember the E or e gene is the extension gene. The A or gene is the agouti gene. I have two bay mares. Mother and daughter. One is homozygous for both. One is heterozygous for both. But both combinations let the dominant genes show through. I constantly have to go back to their papers to dream of what they "might" produce. Still the two mares look so much alike with their BLACK points (legs, mane, tail) and their RED body. **** to **** is dominant. Hetero to hetero will be dominant 75% of the time and recessive 25% of the time. It is fun to be geeky about something.

 

[little lady]

I love horse genetics...so facinating. Coming from raising Paint Horses I thought that was an added dimension but these miniatures have a whole other color wheel...lol! The Paint Horse Journal had an excellent article(in the February issue) on homozygus tobiano pattern and the homozygus black, addressed the agouti factor and red factor and it was easy to understand.

 

[~Amanda~]

I love equine genetics too. It's incredibly fascinating to me. One of the reasons I like Minis so much is they come in such a variety of colors. They can be simple and lovely, like a nice black or bay, or really complex like a Silver Buckskin Pintaloosa.

It's great!

 

[JWC sr.]

I really enjoyed all this stuff, because we work with other animals that are sometimes triple and quadruple heterozygous in order to produce specific color and pattern morphs. But it always makes my head hurt.

Thanks for the fun of reading all this it was great.

 

[Dona]

Is it truely a palomino? Is it possible that the palomino carries silver?Silver is "black". Some homozygous for black horses have thrown silvers and some silvers have thrown homozygous for blacks.

I'm not a color expert (LOL) but if a palomino has indeed had a homozygous for black foal, then that palomino (IMO) carries silver in some form (or is even a silver bay somehow?)

I'm sorry Robin, but you are wrong here. Maybe you "meant" that a visual Silver horse is a black based horse, I dunno...but let me clear this up so people don't misunderstand.

Silver is NOT black.

Silver is not a color, it is a "modifier" that only AFFECTS black. A true Palomino cannot throw/produce a homozygous black foal, whether it carries the silver gene or not.

 

[REO]

Thanks Dona! I forgot that part! LOL

I need more coffee I guess!

 

[Dona]

Yea....I figured that was what you meant to say, Robin.