[JBandRio]

Originally Posted by PeggySue

No this comment does not make sense to me

A horse who has ONLY the Tobiano gene and no other pinto gene will have a solid colored head. It's just what Tobi does. So, if there is white on the head, it's the result of one or more forms of Overo. That makes it Tovero.

[PeggySue]

JB I don't see how anybody can say that .. if that tobi is out of a QH mare that has a star then it could have a star with no other pinto pattern there

[prairienights]

I was pretty tickled to find this thread, because I was actually thinking about posting the exact same thing on the bus ride home this afternoon, haha.

And PeggySue, I agree with you, I like my solids. (well, a tiny smudge of a star on my boy is ok)

Anyways, everyone has pretty much covered the articles I know on the subject. But I just wanted to add that there are certain breeds that seem to have a lot less white than others. Morgans aren't usually as chromey, Cleveland Bays usually don't have white (except for a star or something). Don't see many Friesians with a big blaze.

[JBandRio]

Originally Posted by PeggySue

JB I don't see how anybody can say that .. if that tobi is out of a QH mare that has a star then it could have a star with no other pinto pattern there

Ok, I'm confused now about what you're confused about

Your comment about not making sense was directed at

If a tobiano has facial white it is a tovero

right?

If it's Tobiano, it's Tobi. If it also has facial white, there is also an Overo pattern at play - Sabino, Splash, or Frame. If it's a star, you can be pretty sure it's Sabino.

I don't understand the comment "if that tobi is out of a QH mare that has a star then it could have a star with no other pinto pattern there" I'm assuming "that tobi" you refer to is the "tobiano with facial white" referenced earlier.

If a Tobi with a star is out of a QH mare with a star as the only white, then the stallion had to have been Tobi, and the combination of the Sabino from the QH mare with a star as the only white, and the Tobi stallion, can easily produce a Tobi with a star. It's still a Tovero - Tobiano + Sabino Overo.

[Little Red Dun]

From what I understand, there are many genes/types of Sabino. SB1 is simply the only one found at the moment, and thus the only one with a test for it. It has been found in Tennessee Walking Horses, Paint Horses, and Shetlands to name a few, but some breeds that clearly have Sabino, such as Clydesdales and Arabians have all tested negative so far.

I was under the impression that all white markings are a form of Sabino. I believe this for a few reasons. One, because near-solid horses can suddenly have pure white foals. Two, some breeds have almost completely bred out white markings, such as Friesians.

To be able to produce such markings or remove them from a gene pool, they have to be caused by a gene or genes, right? Now, I do think there are some outside factors in how the white markings are expressed, specifically in utero. Clones of horses can exhibit very different markings from the original, for example. However, I've never yet seen a clone with white if the original horse had none.

[accphotography]

Originally Posted by Little Red Dun

I was under the impression that all white markings are a form of Sabino. I believe this for a few reasons. One, because near-solid horses can suddenly have pure white foals.

Exactly! That is the current belief by genetic researchers is that all white markings not found to be caused by one of tobiano, frame, splash or rabicano, is sabino. I very firmly believe this is true. Also for the same reasons as LRD. How can two horses with only a star (STst + STst or some variation thereof) produce an all white horse? One big star? Doubtful.

ACC

[Smoke N Lace]

Originally Posted by accphotography

Exactly! That is the current belief by genetic researchers is that all white markings not found to be caused by one of tobiano, frame, splash or rabicano, is sabino. I very firmly believe this is true. Also for the same reasons as LRD. How can two horses with only a star (STst + STst or some variation thereof) produce an all white horse? One big star? Doubtful.

ACC

But, animals in the wild occasionally produce an all white offspring. (I don't mean horses.) What genetics are at work when that happens?

[Little Red Dun]

Originally Posted by Smoke N Lace

But, animals in the wild occasionally produce an all whte offspring. (I don't mean horses.) What genetics are at work when that happens?

Those are often albinos and have pink or blue eyes. Maximum Sabinos do not; they have dark eyes like Patchen Beauty and her foals, etc. The genetics are difference.

Occasionally you will get a mutation or the product of a recessive gene together to make an unusually pale coat. However with the "white" horses, they often breed true, which the unusually pale/white animals in the wild 99% of the time do not.

On the rare occasion one of the wild animals with unusually light coats breed true, it is almost always with another light-coated animal or one carrying that gene, like the white tigers, etc. With "white" horses though, they usually have "white" foals at least 50% of the time or more.

[JBandRio]

Originally Posted by accphotography

How can two horses with only a star (STst + STst or some variation thereof) produce an all white horse? One big star? Doubtful.

Why doubtful? Why is that any harder to think that a max sabino is just 4 really tall socks?

[PeggySue]

I ahve been digging for two days and can't find any genetic research on JUST stars and leg markings that is not related to BIG white markings..

ANYBODY??