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Unusual Homozygous Tobiano Patterns

I have a miniature horse stallion, and now several mares that have an unusual homozygous tobiano pattern. None have any appaloosa in their pedigrees. I suspect sabino and in some cases splashed white. So far these horses have all come from horses that did not look like their parents and they have only occaisionally reproduced themselves. [color=#FF0000]This is the stallion Jazz. He is TT, LWO Neg, Ee, Sb1 Neg.[/color] [img]http://pacificpintos.com/referencesires/images/jazz1.jpg[/img] Here are a few of the mares: [color=#FF0000] Lakota Stars: TT, LWO Neg, Red Factor and Sabino ?? [/color] (She has not been tested yet. We are waiting for her arrival which has been delayed by snow road closures.) [img]http://pacificpintos.com/broodmares/images/lakota2.jpg[/img] [color=#FF0000]Deelite: TT, LWO Neg, EE, SB1 Neg.[/color] [img]http://pacificpintos.com/broodmares/images/deelite2.jpg[/img] [color=#FF0000]Rose: TT, LWO Neg., Agouti Aa, Sb1 Neg.[/color] [img]http://pacificpintos.com/broodmares/images/mehe1.jpg[/img] 2011 will be the first foaling of the stallion to one of these mares. Are any of you breeding a horse with simular genes and can you give me any insights as to what to expect or how to produce foals like these horses??? Thank you for your help.

Threnody Tue, 12/28/2010 - 15:48

Since they are all homozygous tobiano the foals are guaranteed homozygous tobiano so ink spots will be expected. Since the stallion's face is solid I doubt he carries other patterns, so you likely won't have to worry about homozygous splash in the foals covering up any ink spots since only the mares appear to carry it. Because the stallion's dam was chestnut he could sire chestnut foals occasionally from any mares who aren't homozygous black.

As far as recreating the parent's colors in their foals, you appear to have a very good line up to attempt this with.

Danni Tue, 12/28/2010 - 17:10

The stallion especially has quite wild markings I reckon!! My personal thoughts on the inkspots/paw print type markings is that it's some sort of mutation that is very close to tobiano, so usually links to it. It creates those ink spot type patterns when homozygous. Why I don't think tobiano specifically causes them is because there are just too many homozygous tobianos around with no spots, and plus the ink spots seem to run in families.

So anyway I think your chances of producing more of them with those mares and that stallion would be very high!!!!

Pacific Pintos Tue, 12/28/2010 - 20:19

O.K. Newbie alert! :newbie

Sorry about the original post, I will get up to speed soon. I promise :oops:

I have added what genetic tests have been done to the photos above.

I am completly facinated with where your line of thinking is taking this. I always assumed that each of these horses would carry a sabino gene that we could not test for at this time.

The thought that it could be a mutant tobiano gene never came into my mind. Also, the ink spots running in families, is also an interesting and new concept for me.

Pacific Pintos Wed, 12/29/2010 - 10:28

In all these horses, if you see foal photos not all of the spots are visible at birth. Once the foal coat is shed or clipped off you then see a multitude of spots, especially the high "freckle " concentration that seems to appear on the hip areas.

Here is the other side of the stallion. Note the high concentration of "Freckles" that almost appear to be a "smudge" but are made up of individual dots:

[img]http://pacificpintos.com/referencesires…]

And a couple of his foals:

This is a filly of his who is now in England. Filly is TT,EE.
[img]http://i287.photobucket.com/albums/ll13…]

Dam of above filly: Her dam is Tt, EE.
[img]http://pacificpintos.com/broodmares/ima…]
[img]http://pacificpintos.com/broodmares/ima…]

His first colt: TT, EE. There is a multitude of "freckles" under the white fur on his hip and down his leg like on his sire. These are not present until he sheds or is clipped.
[img]http://i287.photobucket.com/albums/ll13…]

Dam of above colt: TT,Ee, Zz (Splash) She has a large silver grey colored belly patch and one black ear. Some black pigment including around one eye.
[img]http://pacificpintos.com/broodmares/ima…]
[img]http://pacificpintos.com/broodmares/ima…]

Another TT Colt:
[img]http://i287.photobucket.com/albums/ll13…]

Dam of above colt: Tt, Ee.
[img]http://pacificpintos.com/broodmares/ima…]

Pacific Pintos Wed, 12/29/2010 - 11:01

Ahhh, the grass is always greener.

A friend that has "full size" horses calls my minis "Key Chains".

She is always saying the same thing, "If only it was a full size horse".

And me? "If only it was a miniature horse" to her larger horses!

Fortunatly the genetics are the same so we can still discuss them.

Threnody Wed, 12/29/2010 - 12:30

In tobiano the pattern does not progress so the spots were there, but the foal coat likely hid them. For example, classic roan foals are often not born appearing roan but if you part the coat you can see white flecked hairs hidden in the colored ones. By the time the foal coat sheds they finally appear roan, though they were roan since birth. Different colored hairs can grow at different rates and have varying texture between them causing this effect.

The minis also tend to "skew" patterns (different canvas for the color genes to work with) so those ink spots are much more dramatic looking on your minis than seen in most regular sized horses. Being black based also helps since black pigment is more rugged and likely to push through white markings to express than red pigment.

Also just wanted to say it's great that you are keeping tabs on LWO status of your breeding stock. ^_^

Pacific Pintos Thu, 12/30/2010 - 10:14

[quote="Threnody"]Also just wanted to say it's great that you are keeping tabs on LWO status of your breeding stock. ^_^[/quote]

We started in raising pinto miniature horses 17 years ago. At that time there was no dna test for the frame gene. I got into breeding frames a few years later. Still no test.

The "white" mare above was born to a mare we thought was a splashed white tobiano based on her parents phenotype. The sire was a blue eyed black and white tobiano pinto. When "Cloud 9" was born I was worried that she might die for the first few days. I called the original owner of the sire and dam and we all agreed the sire and dam "should" not carry frame.

Once the LWO test became available we did test all the possible horses for it, and all new pintos are tested when I get them to know for sure. All my pinto foals from frames that show pinto markings likely to be frames are also tested so that our clients know what they have (they are also tested for tobiano, sabino etc, depending on what their phenotype is). In miniatures there is a stallion called "Rowdy" (now deceased). He was a minimal white (no spots on his body on any photos) Frame stallion. His offspring often skip one generation and then will produce a loud frame foal. If I EVER see Rowdy in the background I know to test the horse. Just not worth a dead foal to me. Not ever. I do know people that routinely cross a frame to a frame and play the odds, but this buisness has enough heartache on its own to not ever have to play with fire.

Since Cloud 9 I have had two other foals born pure white from different sires and dams. In those cases one of them was a frame from both matings. They were born less than a week apart. I have to say even with all my extensive genetic testing and knowing scientifically that these foals have had to be a mixture of several white genes and "whited out", I still catch my breath when I see a pure white foal. Both those completly white foals tested out to be a combination of frame, tobiano, and sabino. A gold mine to a breeding farm that knew what to do with them.

Yes, we test and feel it is worth every dollar to know. We also want our clients to know what they are buying. I get very agrivated when I see sale ads saying they think the horse is a certain pattern when there are tests available to prove it.

Though a splashed white test would be great and I look forward to it.

Pacific Pintos Thu, 12/30/2010 - 13:02

LOVE the leg ink spots on that horse!

Switch Kidder comes the closest to my mares genetically.

Am I correct that we are not allowed to post photos of horses other than our own???

Threnody Thu, 12/30/2010 - 15:34

[quote="Third Peppermint"]You rock. I wish more horse breeders were like you.[/quote]
I second this. ^_^

Rowdy is also one of my personal favorites in the breed. His bold blaze with no leg markings was definite minimal LWO.

critterkeeper Thu, 12/30/2010 - 19:17

[quote="Pacific Pintos"]Am I correct that we are not allowed to post photos of horses other than our own???[/quote]

Correct, unless you have the owner's permission (preferably in writing...lol) but you can post links to said photos.

Welcome PP, :toast you are already a head above most breeders in your ideology, and we commend you for it. I didn't know much when I first started, but these ladies and gents sure taught me a thing or two...and I thank them for it! :love

rodeoratdogs, I personally love the 5th one down, Switchs Black Pearl. What a beautiful example of minimal tobi ... look at those legs... :ymdaydream: (sighs as hubby yells "NO" over the phone at the mear mention of another horse - thank heavens he's in Memphis for the weekend ymwhisle )
ttp://www.paintedfeatherfarms.com/World%20Pho…" onclick="window.open(this.href);return false;

Pacific Pintos Thu, 12/30/2010 - 21:26

The more I think I understand, the more I have foals that leave me baffled. :roll:

Oh well, I really do LOVE horse genetics and LOVE this forum! How wonderful to have all of you to provide feedback! :love

rodeoratdogs Thu, 12/30/2010 - 23:11

[quote="critterkeeper"]

rodeoratdogs, I personally love the 5th one down, Switchs Black Pearl. What a beautiful example of minimal tobi ... look at those legs... :ymdaydream: (sighs as hubby yells "NO" over the phone at the mear mention of another horse - thank heavens he's in Memphis for the weekend ymwhisle )
ttp://www.paintedfeatherfarms.com/World%20Pho…" onclick="window.open(this.href);return false;[/quote]

Oh yeah!, I didn't see that one. I love the minimal tobiano's too and the dark rich mahogany bay color is beautiful, it's almost burgandy.

Danni Thu, 12/30/2010 - 23:13

[quote="Morgan"]The inkspots are normal for homozygous, I'd suspect that the lack of them on some is more caused by having other patterns.[/quote]

I definitely don't agree with this, I see way to many homozygous tobianos without obvious spots

Threnody Fri, 12/31/2010 - 16:01

My own personal theory for inkspots is tobiano attempting to supress itself when there is more than one dose. It tries to prevent other markings in certain areas, so why not itself? ;-)

I don't expect a homozygous tobiano to have ink spots 100% of the time though it is highly correlated. Horses with pattern supression don't always get ermine spots. The environment of the womb also influences where markings fall, so by chance alone inkspots might not happen.

Danni Sat, 01/01/2011 - 04:12

I like my other linked gene theory! :D

I reckon from what I've seen maybe it's half/half with the homozygous tobianos having the spots or not. I have noticed that homozygous inkspotted stallions when having homozygous foals they usually have the ink spots but some lines can be homozygous tobianos and not have any real noticeable spots. I'm talking more the Gypsy Cobs, as I don't have anything really to do with paints.

Songcatcher Sat, 01/01/2011 - 12:13

[quote="Pacific Pintos"]Who did the testing? Was it rechecked?[/quote]
Animal Genetics in Florida. No, didn't have it rechecked. Discovered shortly afterward that she was NOT breeding quality due to locking stifle. Long story. I was not the breeder, but she was born here.

RiddleMeThis Sat, 01/01/2011 - 13:47

Ink spots aren't exclusive to homzygous tobianos. If they were, we wouldn't need to test them.

LOL they are more common on homozygous horses, but that does NOT mean heterozygous horses can't have them too. Similar to fleabitten grays. Its more common on heterozygous horses, but that doesnt mean that homozygous horses can't be fleabitten.