Changing the face (and LOOK!) of TB's in the years to come!

Talk about equine color, markings, genetics, etc. Post pictures of flashy Thoroughbreds!

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Linda_d
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Postby Linda_d » Tue Apr 07, 2009 10:28 am

xfactor fan wrote:Do you know which chromosomes they live on?

I'm trying to put together a list of color markers for chromosomes. KIT and the merry band of whites are a great marker for movement of chromosome 3, and so on.


This is a very interesting discussion and I don't mean to hijack it, but the bolded expression is just about the funniest line I've read in a while!

Thanks, xfactor! :lol: :lol: :lol:

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RiddleMeThis
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Postby RiddleMeThis » Tue Apr 07, 2009 3:03 pm

xfactor fan wrote:Do you know which chromosomes they live on?

I'm trying to put together a list of color markers for chromosomes. KIT and the merry band of whites are a great marker for movement of chromosome 3, and so on.


Im not exactly sure. I KNOW frame is not on KIT, and while they have not found the exact mutation for splash they are pretty sure they know which chromosome its on. Ill find out for you.

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Postby soft hearted » Tue Apr 07, 2009 8:10 pm

Thanks for all your sharing RMT. And for catching my ASS-U-MEption (spelling intentional) on the genetic test.
Last I had heard, published in the Quarter Horse Journal (Aug, '08) was that one doctor had posthumously had her data released regarding the roan homozygousity genetics, but it was being reviewed by Cornell before being published by them.
However, the rest is fabulous reading! Please, keep educating!!

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Postby RiddleMeThis » Tue Apr 07, 2009 8:14 pm

soft hearted wrote:Thanks for all your sharing RMT. And for catching my ASS-U-MEption (spelling intentional) on the genetic test.
Last I had heard, published in the Quarter Horse Journal (Aug, '08) was that one doctor had posthumously had her data released regarding the roan homozygousity genetics, but it was being reviewed by Cornell before being published by them.
However, the rest is fabulous reading! Please, keep educating!!


They know roughly where roan is. Roan IS in KIT or at least VERY close by. But they have yet to find the mutation 100%. I have heard about that research, both bad and good, but have yet to read it for myself. I will probably read that soon to see if what Ive heard is correct.

xfactor fan
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Postby xfactor fan » Wed Apr 08, 2009 1:58 am

The roan embryonic lethal has been quite a question.

To recap.

Breeders of roans (classic roan) have long felt that, and can prove via their breeding records that there is no such thing as a homozygous roan. The theory is that rr is a solid horse, Rr is a roan, and RR is lethal. This is a very early lethal, and mostly shows up in the numbers of roan horses produced.

The expected numbers in crossing two roans Rr x Rr should be 25% rr, 50% Rr, 25% RR, or 1-2-1. The actual numbers work out to closer to 1/3 rr, and 2/3 Rr, with no horses found that were RR.

However Dr. Anne Bowling in her roan study found several stallions that were RR, or pure breeding roans. She died before her study could be published, and the results were released after her death by her husband.

This of course set the breeders up against the science, with the predictable howling from both sides.

Here's the speculation part.


I believe that both sides are correct, and there are two versions classic roan in the gene pool. R1, and R2. Where R2 has a second mutation that moves the lethal gene, so that either R2-R2 is not lethal, or the lethal portion of the chromosomes don't line up exactly allowing the embryo to survive.

R1-R1 is lethal. R1-R2 is not.

Proof of all or any of this is going to have to wait till the genetic testing locates Roan.

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Jorge
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Postby Jorge » Wed Apr 08, 2009 6:16 am

I would like to read that last article by Dr. Ann T. Bowling referenced here and at:
http://www.apha.com/breed/pdf/TheWhiteStuffJan02.pdf (“The White Stuff”, by Rebecca Overton).
Thanks in advance for your assistance.



(p.s. For more information on different coat color articles don’t miss the following thread:
http://www.pedigreequery.com/forum/view ... t=articles )

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Jorge
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Postby Jorge » Wed Apr 08, 2009 7:39 am

Going back to establishing a list of coat colors based on genotypes, world reknown authority, Dr. Phil Sponenberg DVM, set on his book "Equine Color Genetics" (a must for all of us!) the following list of "Usual Genotypes of Major Horse Colors":

01. BAY
02. BLACK
03. BROWN & SEAL BROWN
04. BROWN SILVER
05. BUCKSKIN
06. CHAMPAGNE
07. CHESTNUT
08. CHOCOLATE/BLUE SILVER
09. CREAM
10. GRULLO & LOBO DUN
11. PALOMINO
12. RED DUN'
13. RED SILVER
14. SMOKY
15. YELLOW SILVER
16. ZEBRA DUN

On the other hand, he also establishes the following "Horse Color Names by Category":

01. BAY
02. BLACK
03. BROWN
04. BUCKSKIN
05. CHAMPAGNE
06. CHESTNUT (& SORREL)
07. CREAM
08. GRULLO
09. RED DUN
10. SILVER DAPPLE
11. PALOMINO
12. ZEBRA DUN
13. GREY
14. ROAN
15. WHITE TICKING
16. FROSTY ROAN
17. ROANED
18. PAINT/PINTO (WHICH INCLUDES TOBIANO, OVERO)
19. LEOPARD COMPLEX (this include the commonly known appaloosas)
20 BIRDCATCHER SPOTS
21. WHITE

Comparing and trying to armonize both different list, we can come up with the following suggestions:

01. BAY (already established)
02. BLACK (already established)
03. BROWN (already established)
04. BUCKSKIN (not already established but a natural due to the recent addition of the palomino)
05. CHESTNUT (already established)
06. CREAM (to include the cremellos, perlinos and smoky creams)
07. PALOMINO (already established)
08. GREY (already established)
09. ROAN (this would represent a correction already acknowleged in practically all breeds; TB cases like Red Noble, Odd Colours, Slip Catch, dam of Pink Floyd and his sister are already here as living proof.)
10. PAINT (to include all kind of overos, tobianos, and toveros)
11. LEOPARD (all kind of appaloosas and appy-like eventual cases sporting the 4 reknown appaloosa characteristics)
12. WHITE (already established [sabino-based whites]) (would be open to include all completely white looking cases in spite of their genotype).

Oh my goodness, I was trying to established a genotype-based list but I had to add a couple of phenotype based for practical convenience. Any suggestion on a mainly based genotype list, yet phenotypically practical one? What would you do?

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RiddleMeThis
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Postby RiddleMeThis » Mon Apr 20, 2009 10:48 am

Posting this here as well....There is now a haplotype/zygosity test for roan!! But it is only for QH's and Paints signifying that their may be more than one mutation of roan.

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Postby Fair Play » Wed Aug 12, 2009 2:02 pm

Jorge wrote:Going back to establishing a list of coat colors based on genotypes, world reknown authority, Dr. Phil Sponenberg DVM, set on his book "Equine Color Genetics" (a must for all of us!) the following list of "Usual Genotypes of Major Horse Colors":

01. BAY
02. BLACK
03. BROWN & SEAL BROWN
04. BROWN SILVER
05. BUCKSKIN
06. CHAMPAGNE
07. CHESTNUT
08. CHOCOLATE/BLUE SILVER
09. CREAM
10. GRULLO & LOBO DUN
11. PALOMINO
12. RED DUN'
13. RED SILVER
14. SMOKY
15. YELLOW SILVER
16. ZEBRA DUN

On the other hand, he also establishes the following "Horse Color Names by Category":

01. BAY
02. BLACK
03. BROWN
04. BUCKSKIN
05. CHAMPAGNE
06. CHESTNUT (& SORREL)
07. CREAM
08. GRULLO
09. RED DUN
10. SILVER DAPPLE
11. PALOMINO
12. ZEBRA DUN
13. GREY
14. ROAN
15. WHITE TICKING
16. FROSTY ROAN
17. ROANED
18. PAINT/PINTO (WHICH INCLUDES TOBIANO, OVERO)
19. LEOPARD COMPLEX (this include the commonly known appaloosas)
20 BIRDCATCHER SPOTS
21. WHITE

Comparing and trying to armonize both different list, we can come up with the following suggestions:

01. BAY (already established)
02. BLACK (already established)
03. BROWN (already established)
04. BUCKSKIN (not already established but a natural due to the recent addition of the palomino)
05. CHESTNUT (already established)
06. CREAM (to include the cremellos, perlinos and smoky creams)
07. PALOMINO (already established)
08. GREY (already established)
09. ROAN (this would represent a correction already acknowleged in practically all breeds; TB cases like Red Noble, Odd Colours, Slip Catch, dam of Pink Floyd and his sister are already here as living proof.)
10. PAINT (to include all kind of overos, tobianos, and toveros)
11. LEOPARD (all kind of appaloosas and appy-like eventual cases sporting the 4 reknown appaloosa characteristics)
12. WHITE (already established [sabino-based whites]) (would be open to include all completely white looking cases in spite of their genotype).

Oh my goodness, I was trying to established a genotype-based list but I had to add a couple of phenotype based for practical convenience. Any suggestion on a mainly based genotype list, yet phenotypically practical one? What would you do?


holy moly! Are you aware the JC is still in kindergarten and is not ready for the "big box" of Crayolas. ;)

Don't mind me. I am still ticked that I have bred two BLACK horses who are registered as dark bay or brown. :D

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Jorge
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Postby Jorge » Wed Aug 12, 2009 5:00 pm


reedhill
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Postby reedhill » Wed Aug 12, 2009 6:24 pm

http://www.amazon.com/gp/product/images ... -and-games

PLEASE lets not forget the muti-colored patterns of sabino and overo!! :lol:

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Postby Fair Play » Wed Aug 12, 2009 6:48 pm

Do you guys mind if I send this in to the JC and ask if they have any kindergarten graduates they could put on this project? :lol:

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Jorge
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Postby Jorge » Thu Aug 13, 2009 3:30 am

Jorge wrote:Comparing and trying to armonize both different list, we can come up with the following suggestions:

01. BAY (already established)
02. BLACK (already established)
03. BROWN (already established)
04. BUCKSKIN (not already established but a natural due to the recent addition of the palomino)
05. CHESTNUT (already established)
06. CREAM (to include the cremellos, perlinos and smoky creams)
07. PALOMINO (already established)
08. GREY (already established)
09. ROAN (this would represent a correction already acknowleged in practically all breeds; TB cases like Red Noble, Odd Colours, Slip Catch, dam of Pink Floyd and his sister are already here as living proof.)
10. PAINT (to include all kind of overos, tobianos, and toveros)
11. LEOPARD (all kind of appaloosas and appy-like eventual cases sporting the 4 reknown appaloosa characteristics)
12. WHITE (already established [sabino-based whites]) (would be open to include all completely white looking cases in spite of their genotype).
13. STAINED WHITE (very-white maculated cases but not to the extent of the marked bays, marked chestnuts, etc.)

That's it, along, with the use of the preffix "Marked" (before its color) whenever applicable ---cases like Airdrie Apache.


That's it!!!

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Postby xfactor fan » Thu Aug 13, 2009 10:11 am

While I hate to defend the Jockey Club, there is a certain logic in their using phenotypes. When a horse gets checked into the racetrack it is supposed to match the passport. Listing a white horse as bay is guaranteed to cause some problems at the track.

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Jorge
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Postby Jorge » Sun Jun 06, 2010 9:51 am

Any update on this thread?