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Facial markings on Tobianos....

Surayya December 13, 2011 December 13, 2011

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Ok so I'm getting a tad confused on the big push for Tobiano horses to be Splash, Frame or Sabino if it has a blaze, because [u]EVERY[/u] site I've come across says they can have '[i]NORMAL[/i]' facial markings just like any solid coloured horse has (ie they dont have to be deviod of head markings at all). The below is taken directly off of the NZ Pinto society site, I have 12 different sites up from all over the world atm & all say exactly the same thing: The Tobiano Pronounced (Toe-bee-ah'-no). Common markings seen in Tobiano pattern: The dark colour usually covers one or both flanks. Generally, all four legs are white, at least below the hocks and knees. The spots are regular and distinct as ovals or round patterns that extend down over the neck and chest, giving the appearance of a shield. Head markings are like those of a solid-coloured horse-solid or with a blaze, strip, star or snip. A Tobiano may be either predominantly dark or white. The tail is often two colours. So how come every blaze a Tobiano presents with atm must have come from every or anything other than the usual solid coloured head, random facial marking? I understand if the marking isnt a 'normal' marking, that thats a sign of another pattern at work, but where is the line drawn between 'normal' & 'unusual'? I'm just very curious where this thinking is coming from is all :) :-?

rabbitsfizz Mon, 12/19/2011 - 13:56

"I sit in a camp that feels you leave it alone (name wise) until you know for sure what to call it otherwise it ends up going through so many name changes & functions that the majority simply cant be stuffed knowing (they put it in the to darn hard basket )& turn off then you get the crappy society definitions/ understanding."

Which is exactly my point.
Why call a Black and White horse, untested and unproven, a Tobiano with blaze when it is quite possibly a Tobi base animal + Splash or Sabino?
You cannot have it all ways, you know.
The test for LWO was searched for and found because of lethal white, end of story. It had nothing to do with the pattern, even, it had all to do with finding out why foals were dying, so it was the first pattern to be isolated- with very good reason.
And to be picky, there was Piebald and Skewbald (and still is btw) and then there was Tobiano, Splash, Sabino and Frame.
There has never been "overo" in Europe and I hope to god we can actually bypass this pointless misnomer. Piebald and Skewbald were pointless enough, we do not need to replace them with something even more pointless.

rabbitsfizz Mon, 12/19/2011 - 14:00

I feel I should say at this point, Surayya, that I am not trying to pick fights here, there is absolutely nothing personal in my remarks- I know that some of these comments come over as "snippy" but it is not my intent to insult you. I hope we can continue this discussion and maybe even get to an agreement of sorts! You have obviously thought hard about what you say and think, and I respect you for it.

NZ Appaloosas Fri, 12/30/2011 - 19:42

[quote=admin]It is also thought that all "normal" face white is caused by a white pattern of some sort. [/quote]

Hang on, how 'bout Wolff's white study?

Diane

NZ Appaloosas Fri, 12/30/2011 - 19:49

[quote=admin][quote]
While white patterns are inheritable we know from cloning experiments that environmental factors in the womb do affect expression. Clones with white patterns will have a different markings than the original animal although, I don't believe there has been an example of a solid donor animal having a clone with white or vice versa. There just aren't that many cloned equines.
[/quote]

Scamp? I think the name is, that barrel racing gelding that was cloned so that the owner could breed from it; the original was solid faced, the clone had a star and a lower-half blaze.

Third Peppermint Fri, 12/30/2011 - 20:13

I will say that Scamp and Clayton have VERY different face white, bordering on Scamper having none, but I can't find any decent pictures of his face when he was young. He has a ton of white hairs on his face now that look like old horse greying (I assume) and there's quite the concentration where a star would be. I'd be interested if he had a few white hairs.

My cat totally looks solid white, but when she was a baby she had about 5 black hairs on the top of her head. Maybe it's like that - so few white hairs that the face looks solid?

Edit: this horse has white hairs on his face, but you can't see it in pictures: http://www.equinenow.com/horse-ad-511565

Daylene Alford Fri, 12/30/2011 - 20:23

Scamp wasn't the only one their have been others, none of them have had the same markings as the original.

CMhorses Fri, 12/30/2011 - 23:52

I still love the smart little lena clones; it seems like basically genetics said we are going to have facial white and leg white, but development factors determined the exact placement.
http://lh3.ggpht.com/-w7-P5wFs3hI/SBNrX…
They look like they could have both splash and sabino markings, and its possible that one pattern dominated the other in some clones, but not in others. Also it looks like they could have a white suppressor going on, which could dominate more in the clones with less white, and less in the clones with more white.

Third Peppermint Sat, 12/31/2011 - 15:04

That's an awesome picture CMhorses, thanks for sharing it! It seems to be that cloning is a great way to see what is genetic and what is...not genetic.

This is a cool article if you guys can find the whole thing/ see it. And if you haven't before. http://www.nature.com/nature/journal/v4…

It basically talks about mice that appeared to have a white marking pattern, but didn't have the genes for it. They eventually found it in RNA that had tagged along with the male's sperm and it had come in afterwards and "modified" the expression, resulting in white spots on mice that shouldn't have white spots. Perhaps something like that can also affect the natural horse vs. the clones? Maybe, like in Scamper's case, his sire had some face-white-suppressor RNA that resulted in him have none/nearly no white hair on the face, but then when they "cloned" him the clone didn't have the RNA and actually had the genetic expression?

Danni Tue, 01/10/2012 - 19:39

[quote=Surayya]Ok that clears up some of whats going on here ie. Sabino = Any horse with white markings (no matter what it tests as), rather than sabino = classic sabino & 'normal' white markings = 'normal' white markings (over here Sabino = Sabino , normal = normal).
So what we would call a Tobiano with a blaze (because it's test neg for frame & sab1 & looks nothing like a splash), you are calling Tobiano & Sabino.[/quote]

The way I see it is this, we know splash, frame, sb1, tobiano etc in minimal form can be restricted to 'normal' accepted markings, and not be pinto by registry definitions. So to my mind it is no great stretch to think the other normal white markings are also being caused by a white pattern gene that we simply can't test for yet. Sabino is the commonly used scapegoat name for white patterns with no tests.

However I think you have a good point with the environmental effect, as has been proven with the clones, but I belive there still has to be a 'white making' gene there in the first place. That we choose to lump all those unknown white making genes under sabino at this stage will no doubt change as more pattern genes are found

Danni Tue, 01/10/2012 - 19:42

[quote=rabbitsfizz]I think all registries should opt out of pattern descriptions altogether unless the pattern is backed up by DNA hence a Bay and White horse becomes just that, a Bay and White horse. If it is lab tested it is a Bay and white horse proven by DNA to be carrying Tobiano either TT or Tt, (+ Sab1 and LWO if relevant) otherwise it is just put down as it's actual, visual, colouration.[/quote]

I wish societies WOULD do this!! Simply register then as black and white, or whatever, until there is the test result for tobiano, frame etc.

NZ Appaloosas Sat, 01/14/2012 - 02:36

Wolff did a study in the 1990s on uterine placement and white markings...and it's one of the things that I keep saying I need to refresh myself on and never get around to it...apparently the temperature (warmer/cooler) can affect the placement and/or cause white markings, but I can't remember if it were the cooler part of the uterus or the warmer, and if the "inside" of the uterus (that closest to the inner part of the horse) or the "outside" of the uterus (near the backbone for example) that was the warmer/cooler.

I'm going on a genetics "spree" for papers in PDF once I get my Kindle, which will hopefully be by next Wed!

Daylene Alford Sat, 01/14/2012 - 09:37

You wouldn't happen to remember more info about the study? I have tried to google it but all I get is information on Arrhythmia: Wolff-Parkinson-White Syndrome (WPW) and wolves.

NZ Appaloosas Sat, 01/14/2012 - 17:23

I think it was referenced in the Lp paper...which I have to go locate...it's buried on my hard drive somewhere...