Have you seen this pattern before?

[AversionDragon]

So this Forest Horse Mare is definitely a grullo, but what exactly is the pattern on her?
Quincy Zebra

[BlackOak2]

So this Forest Horse Mare is definitely a grullo, but what exactly is the pattern on her?

She is in fact, not grullo (black with dun), but a bay dun (the brown nose gives her away). The primitive stripes are from the dun gene as well as the gray that travels down her legs and stains her fetlocks.

She has a very nice looking coat. Very nice find!

[AversionDragon]

So this Forest Horse Mare is definitely a grullo, but what exactly is the pattern on her?

She is in fact, not grullo (black with dun), but a bay dun (the brown nose gives her away). The primitive stripes are from the dun gene as well as the gray that travels down her legs and stains her fetlocks.

She has a very nice looking coat. Very nice find!

I would like to see if the dun stripes are something that’s transferable, and whether it’s a dominant or recessive gene. I was busy looking for forest horse mares for a project and then I found her, she conveniently has a good HGP compared to other baseline Forest Horses so she isn’t just a mare with a really pretty gene.

[Nazarach]

She is in fact, not grullo (black with dun), but a bay dun (the brown nose gives her away). The primitive stripes are from the dun gene as well as the gray that travels down her legs and stains her fetlocks.

She has a very nice looking coat. Very nice find!

I would like to see if the dun stripes are something that’s transferable, and whether it’s a dominant or recessive gene. I was busy looking for forest horse mares for a project and then I found her, she conveniently has a good HGP compared to other baseline Forest Horses so she isn’t just a mare with a really pretty gene.

I don't know if the dun pattern is dominant or recessive but the shape tends to be the same if only one parent is dun, if both are and the foal gets dun, it could be from either parent. Also, there is a study about the dun gene somewhere in the color forum maybe there you'll find something on the specifics

[BlackOak2]

I would like to see if the dun stripes are something that’s transferable, and whether it’s a dominant or recessive gene. I was busy looking for forest horse mares for a project and then I found her, she conveniently has a good HGP compared to other baseline Forest Horses so she isn’t just a mare with a really pretty gene.

I don't know if the dun pattern is dominant or recessive but the shape tends to be the same if only one parent is dun, if both are and the foal gets dun, it could be from either parent. Also, there is a study about the dun gene somewhere in the color forum maybe there you'll find something on the specifics

The study is one I wrote up, but it's about the gene itself, not the primitive markings.
http://www.horseworldonline.net/forum/v ... 13&t=11515

From my work on this, I can tell you this much:
Dun is dominant, however the dun pattern is static, i.e. you'll either have a pattern or not and...
It works a lot like Lp patterns and even To patterns, each horse may carry entirely different instructions for each set of markings. If you want to make a specific marking set inherent in your bloodlines, you'll need to breed the markings you like out to all of your herd. The more of these genes that you spread to your herd, the more chance you'll have of solidifying the pattern you want. It's not random, but depending on what the other parent carries, the markings can be overrun and hidden or entirely 'rewritten' and lost.
Although I'm working with bay dun and brown dun in my leopard tarpans and have been for quite some time, I haven't paid any real attention to the dun markings. I can't say whether two minimal expression parents can produce a blatantly primitive marked foal.

Also included in that study is a little information on how the markings appear.

[Stick]

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Could one of you two explain how to tell the difference between a bay and a brown dun, using this gal as an example? Because I very likely would have labeled her as brown instead of bay, so would love to know how not to do that in the future if it's wrong.

[BlackOak2]

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Could one of you two explain how to tell the difference between a bay and a brown dun, using this gal as an example? Because I very likely would have labeled her as brown instead of bay, so would love to know how not to do that in the future if it's wrong.

She is a difficult one, hiding much of her telltale hints. Basically, which you probably already recall, bay's have telltale black points, whereas browns reveal brown points.
When paired with dun, generally speaking, browns will turn gray and can be mistaken for grullos. However, bay's generally keep their bay-colored bodies, they just wash-out a bit.
So if you see a grayed-out dun, it's most likely on a black or brown base. If you have a washed-out, red-colored dun, that will end up being a chestnut or bay base.
She's been grayed-out by dun, so that automatically makes her likely a brown or black base. Then she has color to her (her brown nose), and this tells us that she's not black. Thus we come to the conclusion that she's brown.

Does this help?

[Stick]

She is a difficult one, hiding much of her telltale hints. Basically, which you probably already recall, bay's have telltale black points, whereas browns reveal brown points.
When paired with dun, generally speaking, browns will turn gray and can be mistaken for grullos. However, bay's generally keep their bay-colored bodies, they just wash-out a bit.
So if you see a grayed-out dun, it's most likely on a black or brown base. If you have a washed-out, red-colored dun, that will end up being a chestnut or bay base.
She's been grayed-out by dun, so that automatically makes her likely a brown or black base. Then she has color to her (her brown nose), and this tells us that she's not black. Thus we come to the conclusion that she's brown.

Does this help?

Oh! So she is brown? You called her a bay dun in your first reply to the thread, so I'd gotten confused.

[BlackOak2]

Oh! So she is brown? You called her a bay dun in your first reply to the thread, so I'd gotten confused.

Whoops!
I did!
Sorry. I think it was one of those type what you're not thinking things. I do have a tendency to do that, but generally, I catch it before I post it.
She is brown. Not bay.

[Stick]

Whoops!
I did!
Sorry. I think it was one of those type what you're not thinking things. I do have a tendency to do that, but generally, I catch it before I post it.
She is brown. Not bay.

Ahaha! It all makes so much more sense now. That's so funny. And I suppose I feel a little bit better about my own understanding of genetics, at least on this one point. I really thought I must have been missing something huge there.