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Post by Michelle Clarke on Dec 7, 2007 20:57:41 GMT -5
Word on the net is that UC Davis is preparing to launch the tests for Champagne and Dun . . . ;D
Hope it's true!
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Post by lindaf on Dec 7, 2007 23:34:51 GMT -5
Can you please explain the significance of these tests? Is this to test for hidden factors? Heterozygous genotypes?
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Post by Michelle Clarke on Dec 8, 2007 8:40:24 GMT -5
There are lots of questions open with the dun genes. Take for example the Kigers that are black looking. It is hard to prove dun because they are so dark. Also on the light ones, like my QH crosses, that the creme gene has lightened up.
It is known that the dun is a cluster of genes and it would be great to know if they can pass only certain factors - like a dorsal; but not others. This is a big debate right now in the Andalusian/Luso breed. Mostly there are a lot of grey horses and most are born with lots of stripes, only you don't have a lot of dun or grullo horses running around when they don't grey....many are born with some wild striping, but it fades as they mature. I know of one mare that JP owns that has hard line stripes (looks dun) and is out of a grey mare and a palamino stallion. I will post picts of her tonight.
I know Dianne can have some great input here...
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Post by DianneC on Dec 8, 2007 11:21:02 GMT -5
There are a lot of "mystery" horses that a good test will solve. In Kigers there are a number of horses that look black for a good part of the year but when they fade in summer you can see a eel stripe (sharp, hard edged) dorsal and maybe even arm bars. Chinook, my avatar, is one of those. There are also dark bays with hard edged dorsal stripes. Some people say that these are not duns because their coat color is not lightened. Some say that the coat color is dark because of the sooty gene. Or perhaps the dun gene on these horses is missing the coat lightening part.
There are people who feel that the striping seen on these horses is just countershading (the effect of the sooty gene). See the thread on dun and sooty for more information.
There are a lot of Spanish and even some Arab horses that have dun looking striping. Its caused a stir in those circles as well.
I hadn't heard they have decided for sure that it is a cluster of genes but several experts have suggested it. I know that UC Davis has been working on this test for several years and I will be very interested to see what criteria the test uses.
The other BIG result is that we will be able to tell what horses are homozygous for dun (two dun genes so every foal is dun). That could have a huge effect on whether people chose one stallion or another when chosing to breed their mare.
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Post by lindaf on Dec 8, 2007 17:49:07 GMT -5
This is interesting. I appreciate your taking the time to explain it. Please keep updating.
About the DNA testing to prove relationships.... Do you suggest I have it done whether or not my mare ever produces a foal?
I have the results of her dam's DNA test but not her sire's. I have no idea how to interpret it, what the different markers mean, which ones are significant, etc. I wrote to the lab that did the test, but no one wrote back. I also wrote to her sire's owner because it is stated on their website that they had the stallion's DNA results but didn't get a response from them either.
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Post by DianneC on Dec 8, 2007 20:57:19 GMT -5
The main purpose of a DNA test is to show that the stallion and mare you list are the real sire and dam. It has happened several times that the stallion the breeder said was the sire isn't really. If you want to know that then do the DNA test. The lab will send you back a report that says yes, this is the correct sire and dam. Or no, it isn't. They keep the records there to refer to if they did the testing of the sire and dam so find out where the sire was tested and have them do the testing on your mare. Usually its UC Davis.
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Post by lindaf on Dec 8, 2007 23:50:42 GMT -5
Thanks Dianne.
Linda
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Post by lwood92 on Dec 10, 2007 16:52:59 GMT -5
Someone on another list I belong to sent an email to UC Davis to ask them when the test would be available. Here is their response: "We will be offering the dun and champagne genetic test in the very near future. Please check our Website at: www.vgl.ucdavis.edu periodically as we will provide all the dun and champagne test information as soon as it becomes available." She asked what "near future" meant and they said "We are hoping to offer the test by January of 2008." Looks like it's close. |
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Post by juslyn on Dec 10, 2007 17:36:19 GMT -5
Just thought I'd throw in that many foals are born with primitive markings that disappear with the shedding of the foal coat. My Arab colt was born a darker shade of bay and had very heavy primitive markings. He shed out to a medium bay a shade darker than his dam and then shed again to a black-bay.   Suzy |
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Post by fantasykiger on Dec 10, 2007 18:12:54 GMT -5
Suzy, I am just chiming in here to say that is a beautiful Arab colt.
I am very excited about the dun factor test. No more guessing and wondering is it dun or just countershading a simple test will let you know one way or the other.
I know nothing of genetics but would this test also be able to tell you if your mare or stallion was homozygous for the dun gene as well?
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Post by juslyn on Dec 10, 2007 19:58:35 GMT -5
Thanks! He's the first I've ever bred.
Diane said the test will be able to report on homozygocity. I've used their tests for my Arab mare's color makeup. She's bay, but has produced black-bay and no chestnuts. Her grandsire is black. I wanted to see if she could produce black if bred right. The results said no on black and yes on chestnut. I will say they are very fast on turn around.
Suzy
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