The Moonshiner's Leghorns

[RiverOtter]

You're basically saying the same thing as me I believe. You're just more optimistic and in-depth about it. I'm a "see it to believe it" person.


So you're saying that OLWS foals are albino? When you say "overo spotting gene" you mean frame I assume?

They are white by definition though. Zero pigment every time. I think that's where we are confusing each other. What I call white you call albino. Which works. I guess I've never called it albino in horses because there haven't been any documentation of it like there have been in other animals. If there had been, I'd likely call it albino too... if I knew that's what they were genetically. I'm a stubborn mule.

Cool, lesson time!! Geek out with me!
If you define an white as zero pigmentation, then dominant whites are also white, as are the palest cremellos. Because OLWS foals are not genetically white, only visually white. I am absolutely not saying OLWS foals are albino, nothing is further from the truth.

OLWS stands for Overo Lethal White Syndrome. Every overo/frame horse you have ever seen carries one copy of the overo gene (and possibly also a tobiano gene, but that doesn't matter here). Like Gray, like Cream, one copy of the gene gives a visual effect and roughly 50% of offspring with a Gray/Creme/Overo parent will display that effect.

You never, ever breed Overo to Overo (although I remember when folks did, took the 25% death rate as a given and hoped for a homozygous colt that could live, because frames were that $popular$, showing my age here) because all homozygous overos have a degree of OLWS, which, as the name states, is roughly 98% lethal, the lucky ones are midterm miscarriages before they can feel pain. But, like every other Paint/pinto, genetically, that is still a colored horse, with a gene that causes white to "paint" over part of a colored horse. A bay paint will will still throw another bay unless it carries a recessive for chestnut, etc.

An albino has no genes for color. This is a relatively common mutation that is always recessive. Depending on the species and how color is carried, sometimes Albinism is linked with other traits - in ball pythons, there is a type of albinism that is linked with spinal deformities. An albino genetically carries no color, the color of any offspring is totally determined by the other parent and you will only get another albino if the other parent carries the albino gene. Genetically (although, depending on species, not always visually) this is a white animal.

So, when we say "there are no white horses" it is a horseman's joke, because there are lots of ways to get visually white horses. What we don't have is a breeding population of genetically white horses, which does not mean that the Albino mutation has never occurred in the species (which would be very unlikely) and is more likely to be for the reasons I listed above.

 

[RiverOtter]

Wait, so dominant white isn’t white then? What is it?

Dominant white is a spotting gene that basically causes the horse to have one, all-encompassing spot. A white spot that takes up the whole horse. Genetically, it's taking a colored horse and hosing it down with white paint - the underlying color is still there, you just can't see it, except maybe it will show through in a few flecks.

 

[Painted Calls]

Cool, lesson time!!
If you define an white as zero pigmentation, then dominant whites are also white, as are the palest cremellos. Because OLWS foals are not genetically white, only visually white. I am absolutely not saying OLWS foals are albino, nothing is further from the truth.

OLWS stands for Overo Lethal White Syndrome. Every overo/frame horse you have ever seen carries one copy of the overo gene (and possibly also a tobiano gene, but that doesn't matter here). Like Gray, like Cream, one copy of the gene gives a visual effect and roughly 50% of offspring with a Gray/Creme/Overo parent will display that effect.

You never, ever breed Overo to Overo (although I remember when folks did, took the 25% death rate as a given and hoped for a homozygous colt that could live, because frames were that $popular$, showing my age here) because all homozygous overos have a degree of OLWS, which, as the name states, is roughly 98% lethal, the lucky ones are midterm miscarriages before they can feel pain. But, like every other Paint/pinto, genetically, that is still a colored horse, with a gene that causes white to "paint" over part of a colored horse. A bay paint will will still throw another bay unless it carries a recessive for chestnut, etc.

An albino has no genes for color. This is a relatively common mutation that is always recessive. Depending on the species and how color is carried, sometimes Albinism is linked with other traits - in ball pythons, there is a type of albinism that is linked with spinal deformities. An albino genetically carries no color, the color of any offspring is totally determined by the other parent and you will only get another albino if the other parent carries the albino gene. Genetically (although, depending on species, not always visually) this is a white animal.

So, when we say "there are no white horses" it is a horseman's joke, because there are lots of ways to get visually white horses. What we don't have is a breeding population of genetically white horses, which does not mean that the Albino mutation has never occurred in the species (which would be very unlikely) and is more likely to be for the reasons I listed above.

Dom white horses that show 100% expression would be white, yes. I do agree with that. I'd be okay calling those white.

You're referring to the frame gene as overo. That is confusing me as well because overo isn't a gene, it's a pattern. A small collection actually. So you can absolutely breed two overos together as long as only one carries frame.

Some people (probably a lot) still breed frames together and give zero Fs about OLW foals. I have a friend with a SPB gelding who's sire and dam produced many OLW foals before him.

Frame can also be hidden on solid horses, so it doesn't always show visually.

Homozygous overo? That's a lethal white. You're saying people hoped for that?

 

[Painted Calls]

Dominant white is a spotting gene that basically causes the horse to have one, all-encompassing spot. A white spot that takes up the whole horse. Genetically, it's taking a colored horse and hosing it down with white paint - the underlying color is still there, you just can't see it, except maybe it will show through in a few flecks.

Dom white can express minimally too.

 

[RiverOtter]

Homozygous overo? That's a lethal white. You're saying people hoped for that?

Frame/overo = semantics. You don't get it with the tobiano or sabino genes, and, as it can be so minimally expressed as to be virtually invisible (as any pinto expression) for breeding and functional purposes, it's best to assume overo=frame.

It's almost always a lethal. Very, very rarely, a colt will live and reproduce (fillies will still be too deformed, even if one lives, which is like a 1% chance). And, being homozygous, he will pass the pattern 100% of the time. It was like winning the lottery, and I remember one stallion (said to have been minimally expressed OLWS enough to get corrective surgery as a foal, to give him an anus), who's owners got a lot of hate, but also a lot of stud fees. I want to say there was a Western Horseman article on him in the early 90s if you wanted to go digging.

Dom white can express minimally too.

True. I was simplifying. Have you seen the Japanese Thoroughbreds? Also, the Jockey Club registers foals born white as, officially, white. I think there's a white filly racing now.

 

[Chookwagn]

sheeeesh..... come here for Leghorns and all im getting is Brown horses

 

[Painted Calls]

Frame/overo = semantics. You don't get it with the tobiano or sabino genes, and, as it can be so minimally expressed as to be virtually invisible (as any pinto expression) for breeding and functional purposes, it's best to assume overo=frame.

It's almost always a lethal. Very, very rarely, a colt will live and reproduce (fillies will still be too deformed, even if one lives, which is like a 1% chance). And, being homozygous, he will pass the pattern 100% of the time. It was like winning the lottery, and I remember one stallion (said to have been minimally expressed OLWS enough to get corrective surgery as a foal, to give him an anus), who's owners got a lot of hate, but also a lot of stud fees. I want to say there was a Western Horseman article on him in the early 90s if you wanted to go digging.

True. I was simplifying. Have you seen the Japanese Thoroughbreds? Also, the Jockey Club registers foals born white as, officially, white. I think there's a white filly racing now.

I think a lot has changed since you studied paint genes.

 

[Painted Calls]

True. I was simplifying. Have you seen the Japanese Thoroughbreds? Also, the Jockey Club registers foals born white as, officially, white. I think there's a white filly racing now.

Oh yeah they're cool as heck!

 

[Painted Calls]

sheeeesh..... come here for Leghorns and all im getting is Brown horses

Out lol

 

[Painted Calls]

Frame/overo = semantics. You don't get it with the tobiano or sabino genes, and, as it can be so minimally expressed as to be virtually invisible (as any pinto expression) for breeding and functional purposes, it's best to assume overo=frame.

It's almost always a lethal. Very, very rarely, a colt will live and reproduce (fillies will still be too deformed, even if one lives, which is like a 1% chance). And, being homozygous, he will pass the pattern 100% of the time. It was like winning the lottery, and I remember one stallion (said to have been minimally expressed OLWS enough to get corrective surgery as a foal, to give him an anus), who's owners got a lot of hate, but also a lot of stud fees. I want to say there was a Western Horseman article on him in the early 90s if you wanted to go digging.

True. I was simplifying. Have you seen the Japanese Thoroughbreds? Also, the Jockey Club registers foals born white as, officially, white. I think there's a white filly racing now.

Do you have a link to any of these OLW foals that lived? I have never heard of them.