Pinto pattern restriction genes

[Becky]

I bred 4 mares to a new stallion last year. The stallion is blue eyed splashed, homozygous for tobiano, LWO-. The mares are full pattern splashed white, two minimal splash and one solid. Two of the mares have blue eyes. I was expecting a lot of face white with blue eyes. Nope. All of the foals have very little face white. Most have a tiny snip. Not any have blue eyes.

Previously, when I used a different splashed white/tobiano stallion, I got lots of face white - bald faces and blue eyes on nearly every foal. Especially when I bred him to splashed pattern mares.

How do you know which horses carry pattern restriction genes? Breeding only? I can't wait for more pattern tests to become available!

 

[targetsmom]

I wonder if this question is related to the question I just posed about Rowdy on another thread???

I would really like to know too....

 

[albahurst]

Great question, Becky. I just asked Charlotte how my new foal got so much white on her with a solid black sire and a bay frame with quite a bit of color. She talked to me about the restriction genes, I think. So, I am really interested in knowing more about this subject!

Peggy

 

[Joanne]

Kind of an unrelated question Becky, but as the splashed white gene is associated with deafness, breeding two splashed together would intensify that trait. Maybe there is a locking out mechanism that blocks it to safeguard that possibility.?

Just a thought.

 

[rabbitsfizz]

I do not actually think it would, Joanne, a lot would depend on the status of sire and dam, and the distribution of the white on the pattern.....

 

[Watcheye]

Interesting thread!

 

[Becky]

Joanne, I've had many splashed white horses here and none to my knowldege have been deaf. I love the pattern!

Normally, when I've bred two horses with that pattern together, even if minimally marked, the results have been full patterned foals. I was just so surprised this year with the foals by this particular stallion and the noticeable decrease in face white when bred to mares of like pattern.

I'd love to hear if there are any studies done on patterned horses that seem to 'restrict' the pattern instead of turning it on!

 

[love_casper]

Well, sabino can often intensify the pattern, and make splashes much louder... so perhaps your last stallion carried sabino, which was making the babies louder, and the new guy doesn't. One isolated snip on the nose is usually an indicator of splash so I bet these babies carry it, just not to the expression that the last ones did.

Also, tobiano likes to try and hide splash's blue eyes, so since this guy is homozygous tobi, I bet that's what's doing it. I betcha your last stallion was homozygous splash, hetero tobi, which would explain him producing more loud splashes and blue eys.

Just a few guesses.

 

[Becky]

Alex, those are very good theories indeed.

The stallion I used for many years showed no sign of sabino and neither did any of his splashed white foals.

However, the stallion I used last year definitely showed signs of sabino with roaning in areas in his coat. Yet, he decreased white markings in his foals.

But, it may indeed be linked to being homozygous for tobiano, yet that doesn't explain why my other homozygous for tobiano/sabino/splashed stallion puts loud face markings on about 50% of his foals.

 

[Charlotte]

yet that doesn't explain why my other homozygous for tobiano/sabino/splashed stallion puts loud face markings on about 50% of his foals

It's karma.

Charlotte

 

[targetsmom]

I find this fasciniating and have another (related) question: Could pinto genes affect the GRAYING gene?

The reason I ask is that our colt Max, is a silver bay carrying both frame and tobiano pinto genes AND the graying gene. At 9 months and freshly clipped, he still has plenty of color. His dam - a silver bay, only frame, with the graying gene (1 copy) - was pure white by weaning. The only other color gene difference (besides the fact Max has tobiano) is that she is EE and he has to be Ee because sire is chestnut tobiano. The sire may also have splash (he has a strip & snip and is of course LWO-) so Max could also have splash. Or is there something else going on that is affecting the speed of turning gray?

 

[Dona]

Very interesting thread......but after over 20 years of breeding, I've concluded that getting loud color is just "hit or miss".

Some years I get lots of color.....some years I get NO color using the same breeding pairs. Unfortunately for me.....so, far this has been a "solid" year for me, as well as my friend, who are both using LOUD Frame Overos & Toveros...all carrying Sabino as well.

Of course, I realize if you use a homozygous tobiano....you will always get "some" color. I prefer not to use homozygous tobiano, as it will be passed to the foal every time. Tobiano will usually obscur the Frame pattern to some extent....and I want to be able to get the "complete" frame pattern at least occassionally. So, using mares that are heterozygous for tobiano is obviously going to result in some solid babies. To get the "complete" frame pattern....I need the mare to throw "solid" and my Frame stallion to throw the Frame gene. You may ask then, why don't I use all solid mares with my stallion? Because I DO like loud, colorful babies....and using Toveros (who are heterozygous & carry both the solid gene & the pinto gene) will give me both opportunities. They can throw solid.....as well as pinto. If the mare throws solid & my frame stallion throws frame....I get a Frame overo baby. If the mare throws tobiano or sabino or splash (which most of my mares carry) and my stallion throws Frame....I'll usually get a very loud Tovero foal. If the mares throw their pinto genes & my stallion throws solid....I still get a pinto baby. So, this way, I've increased my chances of having loud foals, and still have the chance of throwing the "complete" frame pattern foals when the right genes cross.

Clear as mud, right!

 

[Becky]

Target, that is an interesting theory. Although, I think there are genes that affect how rapidly a grey horse will grey out? I'm not sure if it has anything to do with pinto, but maybe others have ideas on that.

Dona, I completely agree with breeding heterozygous patterned horses together. Sometimes you get it; sometimes you don't!

I'm interested in what is turning on or off face white. Last years stallion certainly minimized that! While I think these foals did get the splashed pattern in minimal form (all have a little snip), I was certainly hoping for (and expecting!) a lot of face white especially from mares that carry the same pattern.

 

[targetsmom]

About the graying - I should have mentioned that I have heard (on here) that the silver gene will speed up graying. But Max and his dam, Mira each have only one copy of silver, so I would not expect that would be the cause of their different rates of graying. But then, if the silver gene can affect the rate of graying, it is not so farfetched that a pinto gene might have a similar effect, is it?

ETA: Now most people would not be using a gray mini in a pinto breeding program, so this probably doesn't come up too often!! But the result (Max) is well worth the gray gene!!

 

[Dona]

As far as silver affecting graying....I don't know that it actually affects the "gray gene". It's just that a foal that gets both the graying gene AND silver... have 2 "dilution" genes together. (and when I say "dilution", I simply mean any gene that "dilutes" color.)

The Silver gene is already "diluting" a black horse to a much lighter color...silver. Add to that, the graying gene which "lightens" color by adding white hairs throughout the body, and you end up with a "Silver White" foal. They are most times born already white...or will turn white rapidly, usually upon shedding or their first clip.

It may work somewhat like "Max White" Sabino foals. They have 2 copies of Sabino (which is another dilution type gene)which lightens a horses color by adding white hairs). They get hit "double" with Sabino, and it results in a white foal, or one that is mostly white with a sprinkling of color that soon fades.

Anyway....that's my thoughts on the subject.

 

[love_casper]

Man I was gone too long, I've missed these fascinating color topics!

You know, I do vaguely (very very vague) remember on here some discussion on silver affecting gray. Wow that was a long time ago. In any case, grays no matter what they carry are different as far as speed, from horse to horse. Some, as yours did, are completely white by weaning. Others take years and years and never go past dapple gray. I know a pair of percherons that are 16 and 17 that were born black and are still now dark dapple gray. So even if silver speeds it up, it's a bit hard to gauge by exactly how much.

Been thinking about splash and tobiano.... I wonder if the stallion that was throwing the face white on the babies was homozygous splash? And this one not? Since tobiano likes to cover that up, perhaps the homozygous splash was able to "stand up to" Mr. Tobiano a little better and put the loud faces on than itsy bitsy heterozygous splash.

If not...... then I throw out all theories towards simple Mendelian genetics ever making sense in relation to minis!