Talk:Equine coat color

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Sorry, but letal white is no Albinism, lethal white ist Leucism. The cream-gen is a mutation of the albino-locus. Kersti

Your argument would be more persuasive if you spell-checked and cited your sources. The creme gene in horses is a dilution gene. I will assess your argument if you provide me source material to review your claims. Lethal White Syndrome is linked to the frame overo pattern in horses, not really sure if it's either one--leucism or albinism. Dominant white does appear to be albinism if homozygous (WW) foals are born dead, but have the red eyes, I believe...however, will be willing to review horse-specific studies on the matter. There is also an argument that the SB1 gene produces white horses, again, doesn't appear to be leucism per se. See University of California, Davis, Veterinary Genetics Lab for the latest research. Montanabw 06:12, 24 January 2007 (UTC)

When I wrote my last posting, ist was in the middle of the night in germany....

The source for the cream-gen being a mutation of the Albino-Locus and the W-Gen being a mutation of the KIT-locus which is linked also to most genes of spotting-types with black and white spots which are known in mammals. The roan and the tobiano-color in horses are known to be linked to the KIT-Locus as well. As far as I know, nobody exactly knows if the overo-color is linked as well to the KIT-locus, but it is likely to be so, because The second chapter schortly explains alsmost everything known in science about the genetics of coat-color of mammals in that year.

  • Krista Siebel; Juli 2001; Analyse genetischer Varianten von Loci für die Fellfarbe und ihre Beziehungen zum Farbphänotyp und zu quantitativen Leistungsmerkmalen beim Schwein Inaugural-Dissertation zur Erlangung des Grades eines Doktors der Veterinärmedizin; Institut für Nutztierwissenschaften der Humboldt-Universität zu Berlin

If you dont know to read german this may be no help to you. Wait a moment an I will look, which are the sources Krista Siebel had used.

Kersti84.138.38.112 17:04, 24 January 2007 (UTC)

For that the roan and tobiano color is linked to the KIT-Locus she refers to this sources:

  • MARKLUND, S.; MOLLER, M.; SANDBERG, K.; ANDERSSON, L.: Close association between sequence polymorphism in the KIT gene and the roan coat colour in horses. Doctoral thesis, Swedish University of Agricultural Sciences, Uppsala,Agraria 79,V,1997b
  • MARKLUND, S.: Applied molecular genetics in domestic animals with particular focus on the horse. Doctoral thesis, Swedish University of Agricultural Sciences, Uppsala,Agraria 79,1997c

Additionally I found this:
Mice and humans: Piebald spotting (S)
Endothelin Rezeptor Typ B (EDNRB)
white spotting, megacolon
Human illnesses: Hirschsprungsche Krankheit, Shah-Waardenburg Syndrom
Similar illnesses: Rat, Horse

  • BARSH, G.S.: The genetics of pigmentation: from fancy genes to complex traits. Trends in Genetics,12(8),299-305,1996
  • JACKSON, I.J: Mouse coat colour mutations: a molecular genetic resource which spans the centuries. BioEssays,13,439-446,1991
  • PAVAN, W.J.; MAC, S.; CHENG, M.; TILGHMAN, S.M.: Quantitative trait loci that modify the severity of spotting in piebald mice. Genome Research,5,29-41,1995
  • SVIDERSKAYA, E.V.; NOVAK, E.K.; SWANK, R.T.; BENNETT, D.C.: The murine misty mutation: phenotypic effects on melanocytes, platelets, and brown fat. Genetics,148,381390,1998
  • GARIEPY, C.E.; CASS, D.T.; YANAGISAWA, M.: Null mutation of endothelin receptor type B gene in spotting lethal rats causes aganglionic megacolon and white coat color. Proc. Natl. Acad. Sci. USA,93,867-872,1996

For that the cream color is linked to the Albino-Locus she refers to this source: BOWLING, A.T.: Horse Genetics. CAB INTERNATIONAL,1996

Kersti Nebelsiek 17:38, 24 January 2007 (UTC)

Fair enough. I'll look at it, or at least what's online and what the horse-related stuff has...the late Ann Bowling was certainly the expert. That said, a lot of the color stuff in horses is different from that of other animals (such as the points on a bay horse being quite different genetically from the points in, say a Siamese cat). In the meantime, you may actually want to look at equine coat color genetics...this coat color article is sort of the "layperson's" version, while the genetics article is the more "scientific" one. Montanabw 21:41, 24 January 2007 (UTC)

I found something new (the MATP-Gen causes oculocutan albinism type 4 (OCA4) in humans and the underwhite mutation in mice).

Kersti Nebelsiek 08:23, 26 January 2007 (UTC)

That sort of detailed info works best in the articles on the individual colors, so maybe see if you can work it into the cream gene article somewhere...might be something there already, not sure. Also check to see if wikipedia has an article on MATP gene (note in English spelling, it's "gene" not "gen") and if so, maybe it's a good idea to create a wikilink to the article.

Contents

[edit] Brown

Do you not have brown horses in america? UK, Ireland and mainland Europe brown is nearly black but for a bay 'muzzle' - Culnacréann 19:51, 1 March 2007 (UTC)

Genetically, all "brown" horses are bays, carrying the E (extension) gene and the A (Agouti) gene. and they haven't yet sorted out the genes that control how light or dark the coat gets. In the USA, the shade is referred to alternately as "brown," "dark bay," "Mahogany bay" and (annoyingly) "black bay." Depends on the breed registry. I think the Jockey club uses "brown," but, for example, the Arabian registry uses "bay." Some people are insulted to have their horse called "brown" because it implies that the color is dull and boring. I'll look at the article and see if I can clarify. Montanabw 22:50, 1 March 2007 (UTC)

Genetically, all "brown" horses are simply not black; that is all the French research taught us. The agouti-factor test identifies the recessive "a" gene, not the dominant "A" gene. Therefore we only know that the brown horses in the French study were not "aa". They were all either "a?" or "??" but there's no telling, at this point, whether ? = ?. So they certainly do have the dominant extension gene, but one cannot say if they have the dominant agouti gene. Currently there is a man doing research in a private lab in Arizona who is hoping to find that brown is analogous to black-and-tan (At) in mice and dogs. It does look that way, so here's hoping! The other problem is that it appears that brown can be at least as light in shade as bay can be dark. So, we'll see. Countercanter (talk) 03:27, 30 December 2007 (UTC)

Actually, UC Davis can test for the A gene, they use is as a cross test to determine if a horse is a true black or simply a very dark brown or bay. (I own a black that has been so tested) And basically, if a horse has E, then it can't be a chestnut of any sort, period. Montanabw(talk) 00:20, 31 December 2007 (UTC)
The test identifies the recessive allele, not the dominant one.Countercanter (talk) 01:44, 31 December 2007 (UTC)
Based on this site, it appears they can detect the A allele. If a horse is EE or Ee, it might be black or bay, you would have to be able to detect the dominant A to know for sure, and A is dominant over E. However, further discussion of this is on the Horse breeds project page, don't want to repeat the same debate both places. Montanabw(talk) 08:05, 31 December 2007 (UTC)

[edit] Suggested chart

Color name Body hair color Points color (Mane, tail, lower legs) Other characteristics, if any
Bay Red, from light sandy red to deep reddish-brown Black May have faint dark dorsal stripe
Chestnut Reddish-brown, from light red to dark liver brown Same as body or lighter "Flaxen" gene may cause significantly lighter mane
Gray White hairs mixed in with the base body coat, that increase in amount as the horse ages May lighten with age at a different rate from body coat Black skin, foals born dark, hair coat lightens as the horse ages
White White body White Pink skin, blue or brown eyes, foal is born white
Black Black, with no brown hairs Black
Buckskin Light cream Black Horse has single copy of cream gene
Cremello Cream Cream Blue eyes
Palomino Yellow or golden Cream or white Horse has single copy of cream gene
Perlino Cream or off white rust or reddish Blue eyes
Dun Yellow, tan or light yellow Darker color than body, usually black, brown or red Dorsal stripe and sometimes horizontal striping marks on forelegs, occasional transverse stripe on shoulders
Roan Any color body with white hairs mixed in Same as underlying body color (bay, chestnut, black) Foal born roan, does not get whiter as the horse ages
Pinto Large white spots over dark base body color Same as base body color, white where skin is white Many different patterns
Leopard Small spots over dark base body color Consistent with base body color Many pattern variations. Associated with breeds such as the Appaloosa

This was suggested over at Talk:Horse and figured I'd drop it in for folks to work on. Ealdgyth - Talk 00:46, 5 April 2008 (UTC)

Don't know how to work in the dilution gene modifiers other than the [[cream gene], i.e. champagne gene, pearl gene, silver dapple gene, etc...

[edit] Comment on chart

There is a chart at Equine coat color genetics that is very helpful, but take a look at the article here, though, and see if a chart would really fit the scheme: I think that some individual color articles may benefit (such as all the variations in Pinto horse, for example), but for this article, I don't think a single chart could be done. I'm open to debate, but look over the text in the existing article and see...so many colors are broken out into sub-groups and such... Montanabw(talk) 16:05, 5 April 2008 (UTC)

The thing with the chart is, it helps newbies to horses who don't have your and I's long experience with knowing a color. You and I just KNOW what a bay/gray�/etc. is because we've dealt with them for so long. When I was teaching riding though, I found a chart like this above, while simplistic, helped folks see how to break the colors down into a workable base system so they could figure out what color a horse was. We're not just writing these articles for the knowledgable, but for the beginners too. That said, I'm busy today digging up fence posts (blech!) and don't have the time to explain exactly what is up. You'll note that I brought the concept up on the talk page before doing drastic changes (hint hint). I didn't think of this chart as replacing the article's contents, more as supplementing it. Ealdgyth - Talk 17:18, 5 April 2008 (UTC)
LOL! It might work. (My problem is that I don't really like charts except for really simple data). Maybe we could ask a non-horse person (like Gwinva or someone) to comment on overall readability or something? The "World Book" approach, which sometimes works, is to put the simple version first, then get more complicated as you go. Of course, if you think this article is complicated, try the articles like Bay (horse) Countercanter added all her info on genetics! Or white (horse) where we try to explain maximum sabino from dominant white! LOL! But back to the chart: The trick here is to not be redundant. Thought: Maybe your expanded chart COULD work in the main horse article under the color section?
For ease, I'd suggest removing the white adaptations/change/genetics. Take out gray and roan, and the chart is simpler. After all, in the end, gray and roan modify the base color. Anyway, bed for me. Ealdgyth - Talk 04:26, 6 April 2008 (UTC)


[edit] Good info on coat colors

Montana, I see that you have tossed an 'additional info' link I placed here. That's too bad, because it was unique in that it explained the incredibly varied coat colors of a somewhat famous feral group, the Chincoteague pony (and therefore all the more interesting because man had little or nothing to do with the colors, it was all mother nature). It was also very interesting to see which coat colors had gone 'extinct' in this group, again, the result of mother nature. Oh well, that's a shame. Here's the link for anyone who wants to check it out: http://www.chincoteaguepony.hostingrapid.com --AeronM (talk) 01:17, 18 April 2008 (UTC)

Aeron, the link was breed-specific. Once we start this, then the Mustang people, the Brumby people, the Paint, pinto, appy, spotted saddle horse, palomino, and god knows who else are going to think they can add in their links. I've seen it happen. Per wikipedia guidelines, external links are mostly for things that we can't put into the article itself, either due to copyright info or because (like, say, a rulebook or online textbook) they are far too complex to incorporate into the article. If you had a good scientific or well-written general reference that was up to date and not breed-specific, it might have stayed. Montanabw(talk) 03:42, 19 April 2008 (UTC)