[JBandRio]

Very interesting ryu!

Also, not that I think you confused them, just remember that Dominant White is separate from the Tobi and Overo patterns. I just wanted to point that out in case anyone read that and thought that DW was in the Tobi/Overo/Sabino mix somehow.

[ryu2832]

Originally Posted by JBandRio

Very interesting ryu!

Also, not that I think you confused them, just remember that Dominant White is separate from the Tobi and Overo patterns. I just wanted to point that out in case anyone read that and thought that DW was in the Tobi/Overo/Sabino mix somehow.

Yes same gene, different mutation. DW is a nonsense mutation.

But the important thing about that paper is that they got enough horses to say that Tobiano is not caused by the EDNRB gene, it's all KIT.

They found something like 27 variants of the KIT gene--so good luck with the Sabino patterns.... .

[horseyfrk145]

JB, ACC, HAAS, RYU; I just have one question - how in the world do you know all this? I've been googling differnet types of paints/pintos for a while and cant follow this conversation!

[Haas Horse Farm]

LOTS and lots of time studying information and actually arguing about it helps because then you have answers to WHY things can or cannot be.

You have to start with the basic horse and understand how the layers of color work. Then go from there. Also understanding what colors are dominant, recessive, and can and cannot hide.

I guess just being a color junky!

[JBandRio]

Color junky, color geek, take your pick

I've been following color topics for a couple of years now - after a while some of it's bound to stick

[Canadian Sage]

I was just thinking the other day...I DO know a case when this has happened....

Tobiano (my mares sire actually) X Tobiano (gorgeous mare)...came out solid..other than a little bit of face white, and I *think* a small sock....

Wish I had a picture of the resulting foal...but BOTH were very loud Tobi's and the owners of the mare were pretty suprised to see a "solid" foal come out of the cross!

[ryu2832]

Originally Posted by horseyfrk145

JB, ACC, HAAS, RYU; I just have one question - how in the world do you know all this? I've been googling differnet types of paints/pintos for a while and cant follow this conversation!

I'm a Gene Jockey for a living so it comes with the territory.

I'm not personally interested in color or patterning in horses, but I have other projects in other species. I used to be able to keep track of all the rabbit color genes, I had a 21 locus homozygous Jet Black Rex line 8 generations pure when I was in high school (horrible geek even back then).

I'm working on a Whitetail deer breeding project and a Buckeye chicken conservation project this year. I get other odd questions and projects from time to time which make life interesting.

I keep my notes, so I don't have to start over--esp with the chrome questions, I just can't remember it all without help.

[JetdecksComet]

Originally Posted by horseyfrk145

JB, ACC, HAAS, RYU; I just have one question - how in the world do you know all this? I've been googling differnet types of paints/pintos for a while and cant follow this conversation!

Hey... you forgot one... me! Big color geek here, too.

If you have any questions feel free to ask... we love to talk about it! Even if you think it's a silly question, feel free to ask. We all had to start somewhere...

[JetdecksComet]

Ryu... I can't get that link to work in the "blue eye" post. I'd love to have it to save it to my faves so that I can reference it from time to time.

[Haas Horse Farm]

PLoS Genet. 2007 Nov 9;3 (11):e195 17997609 Allelic Heterogeneity at the Equine KIT Locus in Dominant White (W) Horses. [My paper] Bianca Haase , Samantha A Brooks , Angela Schlumbaum , Pedro J Azor , Ernest Bailey , Ferial Alaeddine , Meike Mevissen , Dominik Burger , Pierre-André Poncet , Stefan Rieder , Tosso Leeb White coat color has been a highly valued trait in horses for at least 2,000 years. Dominant white (W) is one of several known depigmentation phenotypes in horses. It shows considerable phenotypic variation, ranging from approximately 50% depigmented areas up to a completely white coat. In the horse, the four depigmentation phenotypes roan, sabino, tobiano, and dominant white were independently mapped to a chromosomal region on ECA 3 harboring the KIT gene. KIT plays an important role in melanoblast survival during embryonic development. We determined the sequence and genomic organization of the approximately 82 kb equine KIT gene. A mutation analysis of all 21 KIT exons in white Franches-Montagnes Horses revealed a nonsense mutation in exon 15 (c.2151C>G, p.Y717X). We analyzed the KIT exons in horses characterized as dominant white from other populations and found three additional candidate causative mutations. Three almost completely white Arabians carried a different nonsense mutation in exon 4 (c.706A>T, p.K236X). Six Camarillo White Horses had a missense mutation in exon 12 (c.1805C>T, p.A602V), and five white Thoroughbreds had yet another missense mutation in exon 13 (c.1960G>A, p.G654R). Our results indicate that the dominant white color in Franches-Montagnes Horses is caused by a nonsense mutation in the KIT gene and that multiple independent mutations within this gene appear to be responsible for dominant white in several other modern horse populations. [Pubmed] [Scholar] [EndNote] [BibTex] [Doi]

http://lib.bioinfo.pl/pmid:17997609