Rock, scissor paper

[DianneC]

If you've ever played this game its helpful to understanding what basic colors are dominant and "beat" other colors. The two base colors for horses are black and red. Everything else modifies those two colors. But because we deal with a lot of bay, its included for this illustration. For a more in depth look go to dungenes.org
Lets say
red is paper
black is scissor
bay (black plus agouti) is rock, the bay gene lightens the body color and leaves the points black

Dominant means that if a horse has two genes of different colors one will be dominant and that is what you will see. The other gene will be "hiding" and can usually only be determined by testing or breeding the horse, usually multiple times.
Red is non-dominant, to have a red horse you have to have two red genes.
Black is dominant over red, a horse with one red gene and one black gene will be black. When you see a black horse it could have its other gene be black or red, but not bay.
Bay is dominant over black and red, a horse with one bay gene will be bay and you don't know what color the other gene is...could be red, black or bay. By looking at a horse's parentage you can sometimes guess what other color could be.
The tricky part is that bay only works on black, since a red horse has no black it can have a bay gene and it won't show. So paper beats rock...kind of.
Got to run to work - more later

[desperatehorsewife]

Work? No! You come back and sit right down here, lady, and finish the Rock Paper Scissors story.

[angelsdream]

I am learning a lot by all this talk of color. It's very interesting, so keep 'em coming!

[fantasykiger]

I love color talk...it is so interesting and fun for me. ;D

[DianneC]

OK lunch time...
First a little more ground work
Red + Dun is Red dun, Black + dun is grulla, Bay + dun is zebra dun (dun).
I've always wanted to know what color a foal could be by crossing two horses. Not the first criteria by any means, but I'm a curious sort...just ask my friends.

A fun and easy way that was taught to me to predict foal color was to draw a tick-tac-toe board. You know, two horizonal lines crossed by two vertical lines to make nine boxes.
Across the top we are going to write what we know or suspect about the sire, down the left side we will do the same for the dam. We'll use Chinook and Lark as our demo. Ready?

Chinook has been color tested and is homozygous for black, no agouti (bay) no red, no cream.
Leave the top left box blank, in the middle top put B for black and D for dun. I don't put in a small a (for no aouti) or small cr (for no cream) - if it isn't there I don't put it in.
In the top right box put in B for black and d for not-dun. He's thrown solids so he has only one dun gene. With me???

OK, for Lark... I know that she has one bay gene - she's dun (bay+dun) and I think she has one black gene. Why? I don't think her grullo sire, Cowboy has ever thrown a red. I suspect she is homozygous for dun as she's had three foals out of Chinook and all were dun or grulla. So...
In the left middle box put BAD (Black+Agouti+Dun), and in the bottom left box put BD.

OK, now lets see what we get. By combining the top middle and the left middle we will write what the foal would have from each parent in the very middle box. We have BD+BAD = BBADD(technically it would be written BBAaDD but don't sweat this). Using the rock, scissor paper what would this horse look like? Black + Bay + Dun is zebra dun.
OK, deep breath. Next possibility would be written in the Middle right Bd+BAD is BBADd again a zebra dun.
Next possibility is written in the middle bottom box. BD+BD = BBDD a grulla
Next possibility is written in the lower right box Bd+BD is also grulla
So far Lark has conceived three times (we lost a dun filly fetus to twisted unbillical) She's had two duns and a grulla.

More to come...

[DianneC]

Lets try Chinook and Calista
Same across the top. Down the side is Red + Dun (technically it would be b,D - no black +Dun) and Red + d? We'll guess that she has one dun gene.
The middle is BRDD, black beats red so a grulla, next is BRDd also grulla, last line is BRDd, grulla again and last is BRdd, black no dun
But we need one more line...what if Calista has the agouti gene? that would make the middle BRADd - Agouti beats both red and black so a dun. And last is BRAdd or bay. If you suspect or just don't know about one of the genes you can add more rows.
Other genes of interest that modify the color...
Dun is a complete dominant one is plenty and two doesn't add anything to the color. So if you have one dun gene you have dun, grulla or red dun. But you don't know if there is one dun gene or two. Best way to find clues is to look at the parents, were they both some color of dun? Has this horse ever thrown a solid foal? or to try the new dun test - verdict is still out on it in my opinion.
Grey works like dun, one gene will make a grey horse. Dun plus grey is very different from the normal grey on a solid color horse. Instead of being born dark and greying out, the foals are born this beautiful light cream or silver with dark legs, stripes, mane and tail. Some look like they've had a pink blanket on and it faded onto them. They stay light and begin greying out at the end of their tail first. Some, like Big Grey, will still have darker points at 17. I'll bet he looked like a very, very light grulla when he was younger. I've had two foals born this really light, almost white color that WERE grulla and not grey beause I knew there weren't any greys in their family for two generations. Since grey is dominant one parent must be grey.

Cream hasn't been proven in the Kiger although there was one or two in the 2003 adoption that I thought should be tested. Cream is semi-dominant, you can see when there is one and you get more when there is two. People tend to get buckskins and zebra duns mixed up because they look similar and there are lots more buckskins. But they are different genes and buckskins are more yellow than duns as a rule. One cream gene on red makes palomino, one on bay makes buckskin, one on black makes black, called smokey black. Two cream genes makes a very, very light horse - cremello (red based) perlino (bay based) and smokey cream (black based) and they all look rather similar.
You can, of course have one horse with lots of different color genes, (imagine an Appy, roan dun) fortunately our horses are more simple. For lots more information go to www.dungenes.org/genetics.htm You can read about the newly discovered brown color too. Its lots more scientific at that site but we have games here.
Questions? I'm not an expert but we have people on the board that are even better at this than me. Ask away.

[spanishsagegrullas]

Hey, Dianne, wondering if Chinny has thrown a bay + dun or black + dun, one that you can clearly see the dun markings, when bred to a non-dun horse. That is, if he has ever been bred to a non-dun horse.

Diane P.

[DianneC]

He's only been bred to a couple non-duns, one foal is clearly grey, one is clearly bay and the other is dark grulla.

[desperatehorsewife]

I looked at the site...my head hurts and my Eeyes are blEEding...

[DianneC]

I know, that's why the game is a fun way to deal with it.
So lets take a more generic case... a dun stallion and a dun mare. I can't do these without actually writing it down in the squares so don't be surprised if you don't get it just by reading this.
The stallion is a dun, is out of a dun stallion and a red dun mare.
The mare is a dun, is out of a dun stallion and a grulla mare.

Sire: Across the top we have BAD (Black+Agouti+Dn) because this is what we see, a bay dun.
The right hand top square...hmm. The stallion's dam is red dun. A red horse has two red genes or it wouldn't be red, because black and bay "beat" red. So the dam of the stallion gave him a red gene - that's all she had to give. This stallion has never thrown a solid foal so we will guess he has two dun genes, one from each parent. We'll write RD in the upper right corner.
Dam of this foal we are breeding is dun, out of a dun stallion and a grulla mare. In the left middle box we write BAD for dun - that's what we see in the dam so we know its there. The dam's sire, being bay dun gave her his bay gene. The dam's grulla mother could have given the dam a black gene or a red gene, we don't know which. So in the bottom left corner we write BD for the possible black and then we draw another row and put RD for the possible red gene.
What color will the foal be? Lots of possibilities but we can see what they are using the rock, scissor, paper method.
First row: BAD+BAD is a dun; BAD+RD is a dun - the horse has a red gene but bay beats red;
Second row: BD+BAD is dun as well (bay beats black); BD+RD is grulla (black beats red)
Extra row: RD+BAD is dun; RD+RD is red dun - two red genes is the only way to get red.
You can see how dominant the bay gene is here, strong likelihood of a bay dun. But once in a while this combination will throw either grulla or red dun.

[fantasykiger]

How fun, I like that game and insteresting...what about the pony and mini gene...LOL ;D I swear if any one is going to throw you off or come in some wild color combination it is a pony or mini' horse. Maybe that is just because the pony and mini the gene pools are so mixed who knows what resessive gene may be hidding just waiting to pop it's head up in he next foal.

[DianneC]

How about a double cream, roan and appy mini? Talk about Heinz 57. This is just about color, there are two genes, one from each parent, for anything that is inherited. So one half of the dna of the sire combines with one half the dna of the dam at fertilization to make the dna of the new foal. I talked to a genetic scientist at work when I worked for a biotech. He said it is possible for the genes to shuffle a bit when they divide to become sperm and egg. The illustration shows a nice zipper like separation of the double helix, each half going on to become a sperm (or egg). But my understanding is that the genes can switch which team they are on as the dna is dividing. If the dun gene is a cluster of genes as some people believe (me too) then maybe thats how we get differences (missing pieces so to speak) in the way a dun gene is expressed. Its not like the cream gene, there you either have it or you don't. Its more like a collection of possible dun markings. This isn't scientific fact, just something to think about.

[fantasykiger]

So this cluster would explain why some get elaborate leg striping or eel stripe dorsals and others get a suttle dorsal and some cob webbing. Not all duns get shoulder bars, just as some examples. It just depends on the how the genes as a cluster seperate and jump on board.

[DianneC]

It hasn't been proved but that's the thought. I think it would explain why UC Davis can't find a single gene for their test.
On the changing teams idea - I got the impression that it happened just once in a while, but over generations it could make a difference.

[desperatehorsewife]

BlEeding. BleEding. Getting dizzy...