I'm confused... Paint genetics HELP PLEASE

doubleopi · Posted: Thu Apr 24, 2008 9:07 pm Post subject:

NZ Appaloosas, I agree with you, I just didn't say it very clearly.

NZ Appaloosas · Posted: Fri Apr 25, 2008 2:29 pm Post subject:

I thought we were on the same page, just wanted to be sure. Very Happy

Diane
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one okie gal · Posted: Fri Apr 25, 2008 3:24 pm Post subject:

Y'all are probably making it too hard for me to keep up. I can't do those tiny fractions in my head anymore so I keep a simple rule and if the work is more than that I go get my notebook.

How about this to simplify the main genetic info regarding horse color:

Barring dilution or modifier genes (there are at least 16 of these), at the extension locus:
EE is genetically (homozygous) and physically black
Ee is genetically (heterozygous) and physically black
ee is genetically and physically chestnut (or sorrel as they really are the same)

Now, anything else that affects the color or lack of color of a horse must be a dilution, a modifier or a mutation. AND I believe that not all of these particular genetic items are found at the same locus. Some work in combination and some appear to only work on certain other genes. Others may appear and be unrecognized or may hide beneath certain other genetic situations. Some of these are dominant over all others and some are dominant only under certain conditions. Some even look very similar and sometimes you can have more than one of these little gems working at the same time. Only actual testing of the horse will give the exact genetic markers. Guessing with only the information tobiano stud and overo dam is bound to end up with most of us all over the place on the guesses and we may be really off on what the actual testing will show.

Anyway, a horse is either red or black and then other genetics come into play. And since Crysann requested simple, don't we all agree this is the correct first step on horse color?

My 2nd post is going to have some additional information specific to Cocoa Jet.

one okie gal · Posted: Fri Apr 25, 2008 4:25 pm Post subject:

Ok, now we can have a little fun with this. Evidently in the US overo is used often to mean "not tobiano" so far as registration of the horse is concerned. So frame, sabino and splash are all listed as overo on the registration papers. I don't know if that is how it is done "down under", but evidently it is done differently is South America.

I found some dandy sites that deal with sabino, and it appears that sabino may very well be polygenic (controlled by more than one gene). If that were the case, then using genetic symbols and pinning all to the extension locus might not be the way that it really is happening in a particular horse. Also, there is a sabino registry that lists many of the qualifiers for being registered with this sabnion registry of which a horse only must have at least two of these qualifiers.

So, I did some google work. We know where to find pictures of Cocoa Jet on this forum. Dandy Jet Two, the sire of Cocoa Jet has a head shot on the pedigree page, but his full body shot can be found by looking at the web page for Shiloh Horse Ranch. He is homozygous tobiano.

The dam, Cocoa Reine was lots harder to find. I kept having to read about desserts. Anyway, she appears to be owned by Lucky B Ranch and appears in several pictures on their web page. What a big girl!

Long and short, go look at the pictures. See what you think. This is my take on it:

We know that Cocoa Jet is tobiano because it is dominant and her sire is homozygous for tobiano. He could not give her frame or splash because he did not have it to give. Since sabino can come from another gene or gene combo or complex, he may have that and may have passed it along to Cocoa Jet. I don't think she is tovero because she has too much color in places that tobiano has color where on tovero it seems to be more of the white.

Cocoa Reine. I counted 4 qualifiers (at least) for her according to that sabino horse registry (they only require 2). So I'm pretty sure she is sabino, but again because sabino can come from more than one place she may be more than ONLY sabino. What if she were a frame overo with minimal white plus sabino?

Please humor the old woman and think it over. Do you see anything which would prevent this being the case? Could she (Cocoa Jet) be dominantly showing the tobiano gene with a frame gene being hidden or masked in some manner and also be sabino due to sabino being available to her from a different gene locus? If so, would you not recommend that testing also be done to make sure that if Cocoa Jet is bred she and her "prospective" mate do not have the frame markers which could cause a lethal white foal? Of course I might be tempted to test and look for the possibility of having a mare that could produce a maximum white sabino if for sure she wasn't carrying a frame overo gene (I really do try to look at the bright side.)

susiE · Weanling Joined: 23 Feb 2008 Posts: 3

horsetrainer89, I highly recommend you look up the difference between a phenotype and a genotype. I also highly recommend you learn to be more polite in your interpersonal skills. I also recommend that you learn to describe things in such a way that they will make sense to people reading them, and not just be a confusing muddle of 'trying to be scientific and sound like I know what I'm talking about' mess. Good day.

horsetrainer89 · Posted: Sat Apr 26, 2008 2:17 pm Post subject:

Ok, let me clearify. In the Ede, the d is just a letter to express the extension gene in a black horse and nothing else. It is just a way that geneticists right it out. You are right in the fact that eeAa, eeaa, eeAA, etc. are all going to be a red type horses, but news flash, the a's don't even matter if the e's are lower case. They only matter if one of the e's is capitalized, which then indicates that it is no longer a red color, but it is a black color. Looking more into the formula, then it might change into a cremello, palomino, etc. if it is a red color, or if a black color, then it could be a perlino, bay, etc.

Here is a little of what I mean.
base color:
ee-red
Ee-black
EE-black
Ede-extension black and if you see this, nothing else matters

Now for some colors and their formulas:
Black- EEaa
Eeaa
Bay/Brown- EEAA
EEAa
EeAA
EeAa
Chestnut/Red- eeAA
eeAa
eeaa
Smokey Black- EEaaCc(as exponent: cr after little c)
EeaaCc(as exponent: cr after little c)
Buckskin- EEAACc(as exponent: cr after little c)
EEAaCc(as exponent: cr after little c)
EeAACc(as exponent: cr after little c)
EeAaCc(as exponent: cr after little c)
Palomimo- eeAACc(as exponent: cr after little c)
eeAaCc(as exponent: cr after little c)
eeaaCc(as exponent: cr after little c)

and this list could go on and on forever. I learn from the best so don't under estimate my knowledge. Yes I might get genotype and phenotype mixed up. I always have, but so what. Phenotypes are the coat colors and genotypes are the actual chromosomes, DNA, and chemical make up that are present. And no a homozygous horse cannot be both dominate and recessive. It can't have a recessive(a lower case letter in the genotype) gene. Homozygous has no recessive gene, and both genes must be identical.

P.S.- I got all of my info from a geneticists that teaches the class that I took for college.

horsetrainer89 · Posted: Sat Apr 26, 2008 2:24 pm Post subject:

and speaking of polite, susiE, I would suggest taking your own advise.

NZ Appaloosas · Posted: Sat Apr 26, 2008 8:32 pm Post subject:

horsetrainer89 · Posted: Sat Apr 26, 2008 9:16 pm Post subject:

first of all, smokey creme (in the QH world) is also known as perline and yes by me saying that it is a black horse, I meant black based and you obviously knew what I meant when I said it. When I say red or black TYPE horses, it is basically the word I use to describe it where as you use base. The red genotype with the capital E was exactly what I put, so I am confused as to why you brought that up. And yes I know that every horse has the agouti gene and that red TYPE horses don't express it and I think I have said that around 500 times by now. I am also in touch with one on a regular basis, so that makes two of us and I would prefer to not share their name.

NZ Appaloosas · Posted: Sat Apr 26, 2008 9:30 pm Post subject:

How can smokey creme be considered perlino in the QH world???? All the people I know who breed QHs consider perlino to be double creme on bay. THEY are clued in enough to know that perlino and smokey creme are two different colours.

Well, if you are afraid to name your source, or even where your source is located, I guess I'm right in questioning the validity of your source. As I said, UCDavis is very well known for their work in equine genetics research, as is Univ. of Ky, and not just by me.

Diane
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horsetrainer89 · Posted: Sat Apr 26, 2008 9:37 pm Post subject:

What is the difference then? If you think there is one, then I would love to hear it. As for my source, he lives in Iowa, but that is all I care to tell you. He learned from UC Davis, so I am not sure how that cannot be valid. I know UC is very well know. Doesn't take a rocket scientist to figure that one out.

horsetrainer89 · Posted: Sat Apr 26, 2008 9:43 pm Post subject:

I would also love to see two pictures of them that shows the difference. As of right now, you have not given any facts as to the reason why you believe that perlino and smokey creme are two different colors, so I have no reason to believe you. And the QH people that I know and who actually breed good quality QHs that can make money, have never heard of smokey creme. I have been around horses my whole life and have never heard of it until a TWH person brought the color up and that geneticist that I have learned from said that it is the same color as perlino. Actually, that TWH person was the only one who has heard of that color. Every one else had never heard of it and everyone in there owns a different breed of horse with a few exceptions.

NZ Appaloosas · Posted: Sat Apr 26, 2008 10:52 pm Post subject:

horsetrainer89 · Posted: Sun Apr 27, 2008 7:28 am Post subject:

They are the exact same color, which is why the "smokey creme" horses owner said "smokey creme/perlino" indicating that they are the same color, but can be said two different ways. I saw no difference what so ever. The points show up on both of the horses, so there still is no difference.