# Is there such a thing as Homozygous solid?



## xxdanioo (Jan 17, 2012)

Like a homozygous black? 
They are solid until a pattern is introduced. It depends on the other horse- if their pattern is homozygous or hertrozygous. 

If you breed a solid paint to a homozygous splash then they will have a splash, but if the spash was hetrozygous, you have a 50% chance I believe. 

Someone can correct me if I'm wrong!


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## Poseidon (Oct 1, 2010)

Sure you can have a horse that's homozygous solid...they just don't carry any white genes. :lol:

I'm assuming you mean white patterns. I'm not entirely knowledgeable on how tobiano works if it causes different markings between hetero/homozygous (other than it isn't uncommon for homozygous to have "paw prints", I believe). Though it is entirely possible to have a very minimally marked tobiano.

Obviously you cannot have a homozygous frame , ha. As for splash and the test becoming recently available, it appears to cause minimal markings when heterozygous and over 50% white on homozygous (see the examples here: Morgan Colors- Splashed White Morgans). 

As for sabino, rabicano, etc, I am unsure.


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## nrhareiner (Jan 11, 2009)

Sorrels who have no patter are homozygouse solid.


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## Faceman (Nov 29, 2007)

Sure, solids can be homozygous.

Mine are homozygous for stupid...


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## sommsama09 (Oct 28, 2010)

Haha Faceman *giggles*  Gosh i know alot who are homozygous for hooning and thinking they are "jagger" and that the song "im sexy and i know it" is all about them


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## Chiilaa (Aug 12, 2010)

I think this is a hard one to know at this point in time. Currently, it is widely believed that not only do horses have white creating genes, but that they also have white suppressing genes. These supression genes try to stop white from showing, and what happens is you have white restricted to "normal" markings, such as socks, or stars. However, as more and more tests become available, we will learn more and more about this stuff.


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## trainerunlimited (Jan 26, 2012)

I don't see how a horse can be homozygous solid, because if you breed it to a paint, you have a 50/50 chance of paint. I've never heard of a horse who wouldn't throw a paint when bred to one. If you breed a solid to a homozygous paint, you'll have a paint, right? Please correct me if i'm wrong.


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## Faceman (Nov 29, 2007)

trainerunlimited said:


> I don't see how a horse can be homozygous solid, because if you breed it to a paint, you have a 50/50 chance of paint. I've never heard of a horse who wouldn't throw a paint when bred to one. If you breed a solid to a homozygous paint, you'll have a paint, right? Please correct me if i'm wrong.


White trumps base color...


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## Chiilaa (Aug 12, 2010)

First off, what you're thinking of is "pinto", not "Paint". A Paint is a horse registered with the APHA. A pinto is any horse that has a white pattern that displays more than "high" white - more than leg and face markings really. 

As I said, there is more at play. We have documented evidence of tobiano horses that have "minimal" white when they are homozygous for tobiano. Some just have a single sock, or no white at all. So yes, breeding to a homozygous tobiano, for example, guarantees that the foal will have a copy of the tobiano gene. However, this is no guarantee of pinto markings.


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## nrhareiner (Jan 11, 2009)

Here is an example of a homozygouse solid horse. Does not matter what you cross her with she is still homozygouse solid.


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## Chiilaa (Aug 12, 2010)

Has she been tested to prove it NRHA??? *whistles*


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## nrhareiner (Jan 11, 2009)

Yep she is EEAA and has no other color genes going on. She does not even have any white markings. Few white hairs on her head and that is it but no white under the hairs. Same as her dam.


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## Chiilaa (Aug 12, 2010)

*whistles* 

Until there is a test for all types of Rabicano, Sabino, Dominant White, and Splashed White, then we can't assume that a "solid" horse is not carrying a white pattern. We already know that frame and tobiano can be present in a horse with no white at all. There is nothing so far to suggest that the other white patterns can't be so minimally expressed as to not express at all.


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## Cinnys Whinny (Apr 10, 2010)

trainerunlimited said:


> I don't see how a horse can be homozygous solid, because if you breed it to a paint, you have a 50/50 chance of paint. I've never heard of a horse who wouldn't throw a paint when bred to one. If you breed a solid to a homozygous paint, you'll have a paint, right? Please correct me if i'm wrong.


This is actually what brought up the question. Cinny's dam is a solid sorrel with no white markings at all. Her owner has been breeding her to paints swearing that she will one day throw a paint. 10 foals later, no color. Cinny is the first in a long line of solid paints from this mare. 

I don't know if she has ever genetically tested the mare as I'm not close enough to the person to ask, we are mere acquaintances, mainly because I 1) bought a horse from her and 2) we participate in a lot of the same clinics. I've seen all the offspring in person back when I got Cin, and the ones who have been born since, on her Facebook... and she always seems disappointed when the foal is born....solid. Some of the more recent studs were guaranteed color producers too.


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## Chiilaa (Aug 12, 2010)

Case example - look at Friesians. They are fairly pure bred as a breed. They don't allow outcrosses at all. Occaisionally, you get one that is chestnut (they call it fox) or you get one that has a star, or a small white spot on a heel somewhere. This is what leads us to believe that there are white suppression genes in horses. The white genes are there, they just don't express phenotypically.


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## nrhareiner (Jan 11, 2009)

The mare I posted has no white nor dose her dam. They are solid bays. Her sire is a solid bay no white at all either.










She has been tested for frame sabino and tobie as it was part of the test. Even though there is no way she can be Tobie being a full QH. This mare is about as homozygous solid as you are going to find.


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## Chiilaa (Aug 12, 2010)

I am picking up what you are putting down NRHA 

All I am saying, is that until we have a test for every single white pattern, we can't definitively say that a horse does not have any white patterns at all. There are a few breeds where white is not allowed and yet still occurs, and other breeds where white is not as desirable as solid (such as QHs), and yet crop-outs occur in them too. The white is there, but the supression genes are there too. One of them has to win - in breed where white is desirable, white suppression is not as common.


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## nrhareiner (Jan 11, 2009)

I too get what you are saying. However look at her padigree. On her dams side there is no white on any of the horses. Her dam is a g-daughter of Poco Bueno who has no white. Bottom side of her dam is the same way. Her sire is by Docs Hickory who has only a very small white star. Now there is Doc Bar who has more white but past that there is very little with in 3 generations. 

I agree that with the lack of testing it is hard to say but with the exception of splash she has been tested for every other pattern that has a test and is neg for all.


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## CLaPorte432 (Jan 3, 2012)

Interesting thread. 
_Posted via Mobile Device_


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## trainerunlimited (Jan 26, 2012)

Wow, this is a bit above my head, genetics wise, lol.


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## Faceman (Nov 29, 2007)

nrhareiner said:


> I too get what you are saying. However look at her padigree. On her dams side there is no white on any of the horses. Her dam is a g-daughter of Poco Bueno who has no white. Bottom side of her dam is the same way. Her sire is by Docs Hickory who has only a very small white star. Now there is Doc Bar who has more white but past that there is very little with in 3 generations.
> 
> I agree that with the lack of testing it is hard to say but with the exception of splash she has been tested for every other pattern that has a test and is neg for all.


Yeah, that's like the old King Ranch horses where they had an aversion to white. When you have generation after generation after generation of no white, it is a reasonably safe assumption any white has been bred out - test or no test, although a test would of course provide the definitive answer...


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## nrhareiner (Jan 11, 2009)

Face that is what I am getting at. She has been tested for everything available up to Splash which I am not going to spend the money to do on her. If you look back at her pedigree bottom side non of the horses have any white. Top side you have to go back 3 generations to Doc Bar to find any white past a very small star.


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## TheLastUnicorn (Jun 11, 2010)

My understanding is there is a strong belief that many types of Donkeys have a very strong white repression gene... Which is why there are few pinto Mules with loud body white, even when the donkey is bred to a homozygous pinto horse. (there are some, so obviously not all Donkeys are carriers)

Following that thought it is suspected that some breeds of horses also have something similar.


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