User talk:Countercanter

1

Thanks for your edits to warmblood and other articles. I happen to agree with you, (lordy, just had an edit war over whether the Pinto was a breed!) but be aware that the "American Warmblood" crowd also starts edit wars, we need to be as careful and NPOV as possible! The breed articles in general need real diplomatic editing, I even had to try and settle a spat between two different miniature horse registries and had a fight for a week over the lead image in the shetland pony article, and none of these types of horses am I even an aficionado. (Sigh) Just a heads up. Best to just be sure to watchlist anything you edit and keep an eye on things. Montanabw^(talk) 21:59, 3 November 2007 (UTC)

Invite

There is now a proposal at Wikipedia:WikiProject Council/Proposals#Horses for a new "parent" horse project. If anyone who looks at this page is interested, they are more than welcome to indicate their support there. Also, there is a discussion over at Wikipedia talk:WikiProject Horse breeds about whether to merge that project in or keep it as a spinoff. Montanabw^(talk) 04:48, 4 November 2007 (UTC)

Invite to WikiProject Equine

This is the official word: WikiProject Equine was quietly created by someone while the rest of us were endlessly discussing a WikiProject Horse. We have an official project! So let's go with it, and I am officially inviting you to formally join! Go to Wikipedia:WikiProject Equine, add your name to the list and see what you can contribute. If you haven't already joined Wikipedia:WikiProject Horse breeds or one of the other "child" or "affiliated" wikiprojects at WikiProject Equine, please feel free to do so. Just trying to tag articles with the new templates has awakened me to the fact that there are over 1000 equine articles in Wikipedia! (My watchlist alone is now at something like 700+) There's much to do and plenty for everyone! Thanks! Montanabw^(talk) 09:18, 29 December 2007 (UTC)

Also consider joining Wikipedia:WikiProject Horse breeds. There are a TON of warmblood "breed" (or whatever) articles in desperate need of help! Montanabw^(talk) 09:51, 29 December 2007 (UTC)

Color stuff back atcha

My reply: First off, you did a really nice job on the Black horse article. And I am thrilled that you are back, because you have a lot of knowledge and access to some source materials that the rest of us can only dream about! But of course, I must argue with you a little, just to keep things livel! (smile)

I took out the phrase "no spotting patterns" in the genetics section because white markings (be it a snip, leopard complex blanket, or sabino-white) don't make a horse not black, and I think this is important to stress in an encyclopedic article.

OK, works for me, just trying to figure out how to work in text to go with the Piebald photo and how to explain that spotting patterns can overlay a base coat color.

Next, here are the three sources I am using to back my responses on the coat dilution issues: http://www.vgl.ucdavis.edu/services/coatcolorhorse.php (The coat color test page at UCD) http://www.thehorse.com/ViewArticle.aspx?ID=7703 "Blue's Clues" http://www.thehorse.com/ViewArticle.aspx?ID=9686 "The Genetics of Champagne Coloring"

[1] Approve Black Gold with "teal eyes" at birth.

Hard to tell from the photo, need a better example than this one. (I can be convinced, but am not yet, ) If the foal does have "teal" eyes, it could be carrying the champagne gene. By the way, only one of those horses looks grullo to me, some with faded or diluted coat color look dull bay (as does the horse in the wiki article on that color)

Buckskin and palomino foals often have blue eyes at birth.

No. Not with a single cream dilute as far as I have ever heard. People used to think this, but based on new research, If a foal has blue eyes, and looks palomino or buckskin, that is indicative of champagne gene dilution (or maybe pearl gene also, at least if pseudo double-dilute). If the eyes stay blue, then you have a double-dilute.

[2] MEMC Ladyhawke "If you look closely you can see the bluish eyes that many cream dilute foals are born with."

Hm. "blueish" Still think that's champagne dilution, would be interesting to see what color that foal's eyes become/became as an adult. Again, not an ideal source.

[3] Concealed Gold shows the orangish ear tufts and blue eyes. "This foal, like many dilutes, has blue eyes at birth that will later darken."

That link didn't work when I cut and pasted, but light eyes that change color are indicative of the champagne gene.

On my "to do" list are to clean up the cream article

Yeah, I'm OK with an improvement there. As long as we stick to the cream gene -- maybe look at dilution gene and the other spinoffs: pearl gene, champagne gene]] and dun gene.

and give more colors their own articles.

Which ones are missing? I thought we had everything under the sun--but if you think we have something missing, let me know. (Because we may have it already, but it just isn't findable -- I may know where it is!) I saw you add Sooty (coat), that was cool. See Template:Equine_coat_colors but be aware that a couple article there lead to spinoffs and we don't have everything in Category:Horse coat colors listed.

I really want to make the palomino and buckskin articles about the colors, moving the "breed registry" info to its own section.

I don't disagree in principle, but the breed registry people are CONSTANTLY adding in stuff that I have to delete, (the latest was that Palominos are true-breeding (!) a genetic impossibility!) so I think a section about the color breeds and their standard does need to remain in the articles, even if downplayed. It seems to work in Pinto horse, if you want to compare it. See also color breed, by the way.

I'd also like to modify the white markings article to make it more clear that there's not really much difference between a snip and tobiano...that it's all just white markings.

No. I actually disagree on this one. That said, on one hand, I suppose you could add a little bit to the markings article with the current thinking about the genetic basis for white markings on ordinary, non-spotted horses. HOWEVER, I really think that a theory that a marking that can appear on any color horse is "not much different" from pinto patterns could even be considered Original research, which says that a new synthesis of existing data can be considered original research. People think of the various pinto and leopard spotting patterns as coat colors, not markings. And horses obviously get white markings without being Tobianos, so I actually would not feel comfortable with you doing that. The spotting patterns are genetically distinct and distinguishable from whatever process makes most non-spotted horses have white markings. Though the article does note some special names of certain odd pinto markings (like the Medicine hat). No one has figured out the genes for basic white markings, and clearly they have located at least some of the genetic markers for tobiano, overo, sabino, and leopard (pattern). (See pinto horse).

So, that's my two bits. Oh, and one more thing. We (you, me, everyone) need to footnote our articles more, or at least be sure you have EVERY source you consulted listed at the bottom of the article. I am getting more and more aware of the way the wikigods are tightening up on Verifiability and even I am starting to take some flak for sloppy citation. (Ouch) I am discovering the hard way that it is WAY easier to footnote articles as you go than to have to go in and add footnotes later. See Thoroughbred, which we are about to put up for WP:FA. It's scary how good those have to be! =:-O Montanabw^(talk) 23:31, 29 May 2008 (UTC)

Hi, I'm really not trying to make you mad, (though I probably am) and I know I'm being fussy, AND I really DO want you to do what you are doing with the genetics stuff, because you do understand the underlying ways many of these genes work better than I do, but basically, what I am looking for are university studies and color gene tested horses verified to carry certain genes. They have tests for cream and pearl at UCD, they have identified markers for champagne, though the gene has not been isolated. (See here). "People say..." isn't verifiable. If there is a university study of a foal which is heterozygous for cream dilution without any pearl gene or markers for champagne (which is a dominant, so I admit to some room for doubt here) then I will be content. You have some good info on genetics availble to you, also, I'm just seeking the science.

According to the article on champagnes I gave you the URL in my earlier message above, "The eye color of a champagne foal is bright blue. By the time the foal is three months old, the color might begin to change to green, and then gold. The eye color of an adult champagne can range from light gold, to green, to brown."

As for where I got my info on no blue eyes with single dilution, the Cremello and Perlino educational association web site has a chart here that only says that blue eyes appear with double dilution. Here's another example: http://bridlepath.wordpress.com/2007/03/14/horse-colour-demystified-the-cream-gene-2/. I also found this page that compared cream dilutes to champagne dilutes somewhat enlightening: http://www.chboa.com/comparisons.html I have not seen any university study or a definition from a breed registry that says anything other than that a single copy of the cream dilution allele lightens the hair coat but not the skin or eyes. All I need is a blue eyed horse that has been DNA tested to have a single copy of the cream gene and also tested to NOT have the pearl gene or the markers for champagne...then I will reconsider.

For an example of a "blue-eyed Palomino" that was pedigree verified to be carrying the Pearl Gene (barlink factor), see here. A horse with both the cream gene and the pearl gene is sometimes called a "pseudo double-dilute."

Many breeders may have bred horses for 50 years and have wealth of good knowledge but still not know what they are talking about when they try to explain genetics (as you so aptly put it about people claiming their horse will "throw black!" -- I currently own a black horse and I have never heard so much b.s. as I hear from people who breed for color! =:-O ) So, to take your examples: the page about "Hershey", for example, comments about the day "when they invent a test for the gene." There IS a test for both the cream gene and the pearl gene at UCD, they list them right on their web site. So either the site is old or the breeders are not aware of the current developments in horse color gene testing. "Hershey's" nice Palomino poppa could well be champagne, I can't see up close if he has the skin mottling, of course, but from a distance, I'd be hard-pressed to tell one from the other. And even if the baby's eyes got darker as she aged, then I'd say it was a certainty, as double cream dilutes eyes' stay blue. Montanabw^(talk) 04:13, 30 May 2008 (UTC)

Blue-eyed blond studs (horses that is!)

Couldn't resist a new header with a goofy title! How about for now we just settle the champagne/barlink/cream difference of opinion by qualifying statements about blue-eyed single dilute cream foals with lots of "might" "sometimes are said to" "possibly" and "maybe" with fact tags (Sure, someone will probably scream WP:WEASEL, but I'll take the heat for that) and just wait until we find more sources one way of the other? Right now we basically have farm sites as sources, which are kind of iffy, and UCD isn't specific enough on theirs to be definitive one way or the other (maybe one of us should call them and see if they can clear any of this up -- preferably with a recommendation for a verifiable source we could use on wiki. Wonder if there is a treatise on horse coat color genetics newer than 2005 or so??) FYI, we put up Thoroughbred for WP:FA. Ealdgyth and DanaBoomer did most of the heavy lifting, so if you want to lend any support for the effort, see Wikipedia:Featured article candidates/Thoroughbred or the talk page of the article. Montanabw^(talk) 04:02, 31 May 2008 (UTC)

"Messes"?

[4] You need to check that out. It illustrates what I was talking about. It doesn't show the basepairs, but rather the amino acid translation (which is 1/3 the length). If I'm reading the article right, tobiano is in there too, but instead of being a simple booboo in the nucleotide code, a mess up downstream of KIT causes the KIT gene to be read backwards. (Correcting myself: it turns a big chunk of the chromosome around!) Or something. Enjoy! :) Countercanter (talk) 03:00, 9 June 2008 (UTC)

Saw your work at gray, but let's collaborate there a bit. When I did the big rewrite on it (about two years ago when I was a less experienced editor), it was a worse mess than now and I put a lot of time into cleanup, trying to keep the best of what earlier editors had there. (OK, so maybe its a mess, and now that my widdle fweelwings were bruised, we are even for all my ruthless edits on your stuff! LOL!) Anyway, my original intent with the photos was to show the variations in gray in a progressive fashion from youth to the older, flea-bitten stuff (really have to take another photo of that flea-bitten mare, she's even MORE flea-bitten now!). I liked a lot of what you did, but I tweaked some stuff. Also, in all honesty, you are the first person who I have ever heard call gray a "pattern." Seems a little close to WP:OR to me -- depigmentation, yeah, but pattern? Anyway, I left the term in the article, but moved it down to a genetics summary in the lead and you can go into more detail in the genetics section (and go for it there, that section is very light and definitely needs improvement).

I'd like you to look over overo and cropout. Sabino I have figured out in my head (at least that its not overo, even if the APHA once thought it was), but the genetics of frame and splash overo are driving me mad -- some sources say they are dominant, but others say they are recessive, and there is also a theory that as many as 11 genes make up overo -- and if overo is in any way dominant, it sure isn't dominant in the same manner as Tobiano. Also, there is lethal white syndrome, which, according to some chat boards, people are now calling the "frame overo test" -- yet the Paint people claim some overos don't carry the LWS allele. (But if they are DELIBERATELY breeding overos knowing there is a lethal in there? Horrors!) Anyway, you want a mess, there's a dandy. The genetics on overo made me rip out hair and I still can't figure it out. (Oh yeah, and then there is the splash overo link to deafness if you want to have more fun!). And how in the he## did Overo wind up in Thoroughbreds? Overo is linked to Spanish lines and does not, to my knowledge, appear in English TB pedigrees, just US ones. Someone sneak in a Quarter horse and not admit it???

As for other "messes," we will have to come to some sort of an understanding on markings and spotting patterns. I'm not at all convinced that a star or a blaze has anything to do genetically with a pinto, so do help sort out the confusion (maybe we could add a genetics section at the bottom of the horse markings article to discuss the current state of the science-- or, by "we" I guess I mean "you" LOL!) You know there are a gob of these articles, I think there are links to all in the horse color template that we are trying to put at the bottom of all the color articles...

Now, onto stuff that needs your look-see and maybe the proverbial ripping into. Champagne gene has been written mostly by other editors, none consistent, and I go over there and do cleanup of what's there, but haven't gone over a lot of stuff that probably needs to be looked at. I did write pearl gene in its entirety, and I wouldn't mind you taking a glance at that (opportunity for revenge after how much I mess with your edits (grin))-- I don't have the access to the good scientific sources you have, so was winging it off UC Davis and various color aficionado sites.

I hope we have enough cross-linking between the smoky black article and the smoky black and smoky cream articles...I think I merged the original smoky black that you redirected into the joint article, but my only real concern is that somewhere people can find out how a smoky cream is a double dilution cream...thought about smoky cream as a separate article, the problem is there is only about one paragraph to say about it, hence the article covering both. Should/could we merge your longer smoky black article into the joint article, or shall they stay split?

Anyway, all for now. I'll watchlist your talk page if you want to answer here, or you can answer on mine. Either is fine. But maybe keep the threads together, either way? Montanabw^(talk) 19:54, 7 June 2008 (UTC)

The short answer to your question about over and Thoroughbreds is... "Yes". Someone did sneak some non-TB probably spanish influenced blood into American TBs. Look at Pan Zareta sometime. That "Shiloh Jr" they are saying "came from nowhere"? Err.. QH. Mittie Stephens is claimed as a foundation mare for QHs. (she's in Denhardt's Foundtation Mares book) and the Newman's were QH and TB breeders. She's just one of many I could document (Someday I'll get the research finished on that book...) Ealdgyth - Talk 20:12, 7 June 2008 (UTC)

"Mess" is an undiplomatic word, but I was referring to my contributions rather than yours, so please don't feel the need to defend your edits! I initially saved the article without the photos put back in, foolishly, and had to kinda throw them back in in a hurry because I had to leave.

No sweat. Montanabw^(talk) 03:23, 8 June 2008 (UTC)

I was taught that anything with unpigmented hairs is a pattern. Gray's inclusion in this category is certainly up for debate, since the underlying skin isn't lacking pigment. For some other people who call gray a pattern, or at least a not-color: [5] [6] And some who think gray/grey is neither pattern nor color: [7]

None of which are particularly scientific sites. Sigh. Lets call it a color unless we can get some university studies or treatises explaining otherwise? (Ealdgyth made me throw out the Mustangs4us site in another article, though it is pretty decent on spotted stuff, they don't necessarily have it all straight)

That's true, but I'm just not the only one who calls it a pattern. The case may be argued that it's a color, it's a pattern, or it's neither. Can we leave the ambiguity in there? The benefit of not saying "Gray is a color" is that people have an easier time getting their heads around the devouring of color. Too bad this isn't Germany where they have a much more descriptive name for it: mold. Countercanter (talk) 17:04, 8 June 2008 (UTC)

Markings I will certainly get to.

Champagne I can hack at but I doubt there are any real studies out there; same for pearl gene. I can look for homologous conditions in other species.

Look over my sources. Champagne was extensively covered in The Horse and as that is an AAEP-sponsored publication (though for a popular audience), it has some science behind it; Pearl is a color with a DNA test from UC Davis, so they are "real" and have some studies, but almost all within the last year. Montanabw^(talk) 03:23, 8 June 2008 (UTC)

Oh yes, I know they are real! I just hadn't yet seen any articles that defined the mode of action or anything.Countercanter (talk) 17:04, 8 June 2008 (UTC)

Instead of having smoky black and smoky cream together, or separate, why not let smoky black be separate and put smoky cream with cremello and perlino? I think that such a division would be more true to the novice identifier: smoky cream looks much more like cremello and perlino.

Cremello and perlino have separate articles. Smoky cream could have its own article too, I suppose, just that there isn't much in it at present. Suggestions for how to expand it? (Or maybe expand that section in the joint article and when it gets big enough, we can rename and redirect?? Montanabw^(talk) 03:23, 8 June 2008 (UTC)

I would say it would be best for each color to have its own article. But yes, for now, lets work on expanding the stuff we have now. As far as what to write...well, I looked over cremello and perlino, and they do (and should!) say pretty much the same thing. Soo...let me sit on that. Or go to town yourself.Countercanter (talk) 17:04, 8 June 2008 (UTC)

WHY in the world LWS is a separate article from frame I do not know. And the disparities you mention are due to manipulation of the different meanings of "overo." The gene that causes frame, Ednrb, is CAUSATIVE for the non-functional colon. The genes are not *near* one another, they are one and the same. I will *certainly* sort that out. I can explain these problems: the mutation on Ednrb is "pleiotropic" meaning has several phenotypic effects. The effect of the regions of unpigmented skin is dominant. The effect of the end of the colon lacking nerve function is recessive. "Overo" horses who do not possess LWS (Ednrb) are not frames. It is trickily worded for someone's benefit, I imagine.

Hmm. Lethal white syndrome has been a separate article since before I started editing wiki and hoo boy do paint people get MASSIVELY touchy about any implication that frame overo "ALWAYS" means the horse carries the lethal gene. Yes, it is politically very touchy. VERY touchy. Maybe it's a case of "denial ain't just a river in Egypt" or maybe there is more going on genetically than just the one gene. All I can say is be very careful, make sure your sources are current, impeccable, maybe discuss both old and new research (be SURE to read the article on overo on the Paint Horse Association web site, just so you know the official version) and let's not merge the articles, instead just be sure we have good cross-linking. I've tackled genetic lethal issues personally in a different breed association and people are unbelievably defensive about this. Montanabw^(talk) 03:23, 8 June 2008 (UTC)

Yuck. I will make sure that I do not make any statements that are up for questioning. Frame gene = dysfunctional nerves of hindgut gene.Countercanter (talk) 17:04, 8 June 2008 (UTC)

My best method of explaining so far is this (and it's convoluted because of my lack of vocabulary, so I apologize): there is a difference, culturally, between the way pinto patterns are treated, and the way white markings are treated. "Both" (and I use quotes because there's 8478621 pinto patterns and 48784201203782781 white markings) are regions of unpigmented skin that give rise to unpigmented hair. "Both" are caused by the failure of the melanocytes to migrate down from the neural crest cells. Just because we have created this distinction between "over the knee/past the eye/over the hock" and otherwise doesn't mean they aren't caused by the exact same process. Roan and tobiano don't look similar, but it's the same process that produces them. There are 21 exons in KIT (which code for an actual protein) and many introns (which code for, among other things, regulatory features such as "make this here and now in this amount for this long"). KIT is hugely important in development. Among other things, it is involved with the migration of melanocytes from the neural crest to the skin. Do you know why cleft palates are so common? The bones of the face, like the skin of the face, grow in from the left and right. Melanocyte migration takes the same path as the growth of the skin. Down from the top, around from the left and right. Hence blazes, snips, stripes, etc. in the middle of the face, the middle of the chest, the belly, the ends of the legs. These regions are where the skin cells, and melanocytes, arrive LAST. Have I done this any justice? I can see this process very clearly in my mind, but as I said, my vocabulary falls short.

That actually makes sense, though I couldn't possibly explain it to anyone else! (LOL!) What I wonder is if you need to write an article called [[KIT}} or KIT locus, or whatever its official name is called, explain all this there, and then we can add wikilinks to it throughout many of the other articles. I actually think that would be very helpful. (Maybe there is an article already??) Montanabw^(talk) 03:23, 8 June 2008 (UTC)

I'm glad that made sense. What I'd LOVE to do is compare the gene across species. "Here is where piebaldism in humans is. Here is where white toes in mice is. Here is where tobiano is" etc. I think I can, but I took Genetics several years ago, and Entrez/etc. have changed a bit since then. But they DO have ways of lining up the genes of different species. I'll see what I can do. KIT does have an article: CD117. The reason it is important in cancer research is that KIT is important to stem cell behavior (such as pre-melanocytes), and if cells get tricked into thinking they're stem cells, they replicate wildly and are, therefore, cancerous. Anyways I'm going to work on this.Countercanter (talk) 17:04, 8 June 2008 (UTC)

If you want my opinion on frame TBs...they're probably no more "impure" than any other color of TBs, since breeding is done by gloriously fallible humans. It's just that they wear the evidence on the outside. Now sabino-whites are a different story: these conditions occur frequently (relatively speaking) due to new mutations. And all evidence suggests that the various strains of sabino TBs aren't even caused by the same mutation.

Genetics are so fun when it comes to fallible human horse breeders. And note Ealdgyth can spot the human messup on overo TBs. Sabino exists in Arabs, that's probably how it got to the TB. I laughed my butt off when the Spanish researchers tested MtDNA and found that yes, Andalusians and Barbs DID crossbreed. The Andalusian people are even snootier than the Arabian people for having horses pure as the driven snow since the dawn of recorded time. Montanabw^(talk) 03:23, 8 June 2008 (UTC)

Sabino wouldn't have had to come from Arabians, though I don't doubt some forms of white markings did. In 1912 and in the 1970's brand new dominant white mutations occurred in different breeds. That's two spontaneous occurrances in recorded history! How cool is that?Countercanter (talk) 17:04, 8 June 2008 (UTC)

Hope this was helpful. Countercanter (talk) 00:05, 8 June 2008 (UTC)

Great fun, yes. Montanabw^(talk) 03:23, 8 June 2008 (UTC)

Summing up

Enjoy the following:

[8] Abstract of an article I do not have access to yet. It explains that the process of domestication will continuously bring new white marking genes into the mix. The other notable part of this paper is that genes for white markings have been mapped to...drumroll...you tell me ;)

[9] The first conclusion from above is supported by older research in silver foxes: when selected for docile personalities, NEW, UNEXPECTED appearances of white markings cropped up WITHIN 10 generations. That is TREMENDOUS. See examples on this website.

This also describes it well, particularly "Selection and Development." Note the sentence "Later my colleague Lyudmila Prasolova and I discovered that the Star gene affects the migration rate of melanoblasts..." ah, like...? (OK it spamblocked the link...)

[10] Allelic heterogeneity = different alleles, same gene, "same" pattern.

• The journal article is largely gibberish to me, other than the summaries. I do not really know how to read those sequencing codes (though I was interested to see them admit that dominant white exists and that it isn't just sabino...though "dominant white" Arabians is freaking me out because the only ones out there (like no more than 20 in the whole world) so far DO appear to be Sabino -white-- dark eyes and no white parents, anyway. What is the full article?

Protein sentences: just read the captions. It shows the human, mouse, and horse sentences lined up parallel and points out where on the gene the different dominant white mutations occur. Sabino and tobiano are left out.

Gah. Okay. I am RACKING my brains to think of another way to explain this. Here, look...

[11] Dominant white mouse. Kit^W-v

[12] Dominant white mouse. Kit^W-v

[13] Dominant white mouse. Kit^W-42J

[14] Dominant white mouse. Kit^W-57J

[15] Dominant white Franches-Montagnes horse, descendant of CIGALE.

[16] Same guy at age 4. Dominant white.

(I really have to wonder if this Franches-Montagnes was a sabino with the gray gene, would explain the same thing...?) Montanabw^(talk) 07:10, 11 June 2008 (UTC)

[17] Dominant white Franches-Montagnes mare.

[18] Dominant white Camarillo White Horse, descendant of SULTAN.

[19] Dominant white Thoroughbred stallion. They do not identify the family but refer to a 1946 stallion as originator of THIS strain of white.

[20] Dominant white Arabian.

Ok. What does dominant white really mean? I get the feeling it has developed this aura of "only one mutation" but the article explicitly states that MANY, SEPARATE mutations at different points on the same gene produce dominant white. Dominant white, like "sabino" and "overo" before it, has the unfortunate role of being a catchbin. *All* that dominant white means is a dominantly-inherited white-spotting gene. It need not be spots of a certain size or shape. It may mean spot on the forehead, spot on the foot, or one giant spot that covers the whole body. We have given several dominant white conditions their own names because they are easily identifiable: tobiano, sabino, etc. Mouse dominant white conditions include gsf spotted coat 1, gsf spotted coat 5, spotted sterile male, dominant spotting 17 Jackson (after the lab), dominant spotting 18 Jackson, dominant spotting 19 Harwell, dominant spotting 1 Baojin, dominant spotting 20 Jackson, dominant spotting 24 Jackson, 27 Harwell, 28 Harwell, 2 Baojin, viable dominant spotting 2 Bruce Beutler (aka Pretty2), 2 Jackson, 34 Jackson, white anemic deaf sterile, sash, Strong's dominant spotting, dominant spotting rio, panda white...jeez do I have to go on? The biggest number I found was 83. All of these genes are on Kit and produce dominant spotting: blazes, white tail tips, belly spots, rump spots, mostly-white animals with dark eyes, etc. Looking at the dominant white horses above, how would you take YOUR definition of sabino and use it to make a meaningful distinction between what you call "sabino-white" versus "dominant white"?

Ah! terminology! To me, "dominant white" means 1) that to get a white horse, one parent must also be white, thus, like Tobiano or Gray, it's a dominant. 2) Not only is it domiant, you also have a dead foal if it gets both alleles, but by a mechanism that is apparently NOT the same one that causes lethal white in frame overos. 3) "dominant white" horses are either solid or white, no spots in-between unless yet another pattern gene coincidentally happens to be involved. (The Camarillo white horse being a pretty good example) 4) Anything else that is "white" and not gray probably is SB-1 or some other thing related to what we refer to phenotypically as sabino. Montanabw^(talk) 07:05, 11 June 2008 (UTC)

I do not explain this for the benefit of Wikipedia, by the way. So this doesn't need to be elucidated in an article.

But you are excited about it, and for good reason. It is fascinating. Not sure where you are going with your thinking, but I can see the wheels turning! (smile) Montanabw^(talk) 07:05, 11 June 2008 (UTC)

No Arabian has tested positive for sabino. They are not sabino-white, unless by "sabino white" you mean sabino-CATCHBIN-white which is just another way of saying dominantly-inherited-as-yet-unnamed/unidentified-white-spotting-gene, dominant white.

Right, mostly. I agree that no Arabian has tested for SB-1, which is ONE gene that produces a particular type of dominant sabino. I doubt they have it, though I guess one should never say never. Arabs also do not have a lethal white, neither overo nor anything else that is "dominant white" (the coat color dilution lethal in Arabs is Lavender foal syndrome and it's different. And probably a recessive, anyway) What I mean for Arabs is sort of what you are calling "Sabino-catchbin" white --but a form that usually behaves in a more recessive or maybe incomplete dominant form and not yet testable -- it's the version that appears to be carried by Clydesdales as well as Arabs -- seen in horses like Mesaoud and Khemosabi who themselves just had a lot of "high white" but some of their get were solid, others quite flashy. like this horse. There is a not-genetically-up-on-it sabino horse color breed registry out there that has a pretty good definition of all the possibilities from lip spots to nearly pure white -- but the "sabino catchall" in Arabs is definitely NOT SB-1 as white Arabians (as far as I have ever seen) never have blue eyes or 100% pink skin -- there's always some black skin, somewhere, even if not much. I'm a little sloppy with my terminology, as this same goofy sabino registry calls a horse that is not even quite 50% white a "maximum" sabino...

• Are you OK with the way the color versus pattern thing is in the gray horse article at the moment (comment on talk page if you want to tweak). I am on one hand OK with ambiguity, but on the other hand, see also term of art, there are ways horse people say things that may not be scientifically or linguistically proper, but we have to acknowledge that there are common colloquial ways of saying things. I think we can handle this by "teaching the controversy," i.e. saying, "while this is commonly called x, the scientifically correct definition is y."
• We can just sit on the smoky cream article for a bit, not a pressing issue. If I get motivated, I'll split it out, but I'm not motivated at the moment.
• Overo is going to need real careful sourcing. (and note we have frame and splash sections there already, plus a mention of sabino, even though it's not actually overo family. When we take on that one, I'd like to bring in Ealdgyth, the goddess of proper citation and referencing. She'll spot fuzzy info in two shakes of a rat's tail. (See what we had to do to get Thoroughbred to FA status! She was the driving force!)
• Which breeds had "spontaneous" white mutations? Interesting. As for Sabino, see Mesaoud, no question he brought sabino into a lot of modern Arabians, and Khemosabi in particular is a source for a lot of it today. Who knows how far back it showed up in TBs, but Arabians are a possible source, then, if not the source. (Whereas Arabians do not carry Tobiano or overo).

All for now, much to do, scary how much. Montanabw^(talk) 01:10, 11 June 2008 (UTC)

Sultan born in 1912, ancestor of the Camarillo White Horses. Cigale born in 1957 ancestor of the white Franches-Montagnes. Plus all the dominant white TBs and Arabians that you're probably familiar with. What I am saying is that Kit mutations are common as far as viable mutations go, so even if TBs didn't have white markings that extended past the knees and hocks, they would inevitably develop them. Studies on the Franches-Montagnes horses show that no matter how hard breeders try to select for solid horses, the nature of domestication will thwart them. Mesaoud undoubtedly had his own type of dominant white spotting mutation that he passed on. Okay. I need to sleep. I know I sound flustered. I'm more excited and trying to share with you something I feel strongly enough about to spend another 6-8 years in school for. PS I am a big Arabian fan and keep very up-to-date on my horsey news so I am aware of the many different families of white Arabians and TBs and such :) Countercanter (talk) 05:15, 11 June 2008 (UTC)

Hmm. I think you GOTTA write an article on the KIT locus, it's cool and could be very interesting. I really wonder if there is any other way to be able to explain any of this within the color articles, we will need a separate article to link to, I think. Food for thought.

I don't know what is so groundbreaking about the comment that white markings crop up in animals once domesticated. (Enlighten me?) I say this because, among others, Gladys Brown Edwards (making the case for abolishing the white rule in the AHA, I think) was saying the same thing in 1973, noting that white DOES crop up in the wild, but as it makes an animal stand out and vulnerable to predation, it is selected against, whereas people favor it and sometimes breed for it. The other question here is that while the KIT locus may control white in general, but it also seems clear that different sections have different impacts and thus I want to be very careful about lumping in all white horses together -- or is that not your thinking?

Take a look at Camarillo White Horse, by the way. A high school kid in Camarillo wrote it and I did some cleanup and sourcing. Classic Dominant whites, indeed - lethal if homozygous and many non-whites in an affiliated registry appendix.

That "dominant white Arabian" sure looks like a "maximum-white" (or sabino catchall white) Sabino to me, note the dark hairs and the dark skin patterning on its butt. Also brown eyes, even if pink skin. I have yet to see a blue-eyed "white" Arab. I'd sure be interested in more pedigree data on this, if you are familiar with pedigrees of "white" Arabian families in general, I'm also interested. I know of sabino whites and some grays that were registered as "white" at times, (including Raffles (horse) of all things!) but not any "dominant white" ones. For one thing, the other sabino-white Arabians I have heard of all came from solid-colored parents, Sabino in Arabians is so far not been linked to SB-1, some say it's a gene complex. And at any rate, even that article notes that "dominant white" is lethal if homozygous (though they also cite a 1979 study on "lethal roan" that appears to have been disproven by Bowling) and though god knows Arabs have their lethals, that ain't one of them! (So far). (On that note, I'm lead editor on Arabian horse, by the way, and we are working on it for FA, you may want to comment on the talk page there about the sabino and rabicano sections.)

Now that White TB IS really white, I won't argue on that one, and I've seen other examples (light eyes and pink skin). I won't speculate if that was a mutation or if it just comes from some non-Arabian source (as does Palomino, which also appears in TBs). I'm less a believer in spontaneous mutations in horses than some unscrupulous or careless breeder letting some stray into the pasture. IMHO Human error is WAY more common than spontaneous mutation! LOL! Montanabw^(talk) 07:05, 11 June 2008 (UTC)

Hmmm. A system.

You suggest that only the mutation in the Camarillo White Horses represents dominant white and we ought to call the rest sabino. Let's clarify and set up some rules for terminology. First off, let's use sabino to describe actual sabino. True sabino. Sabino proper. Everything else can just be white markings, or better yet, a white pattern. A star is still a pattern.

Not precisely, the Camarillo is just an example. And I agree, other breeds have white horses that are not Sabinos. And what do YOU mean by "true Sabino" Only SB-1?? Even UCD isn't that limited.

To clarify, my use of terms are as follows, and I have answered your suggestions below, too. Once we know what each of us is describing, we should be back on track!

• First I think of what has been colloquially been called "true white" or "dominant white" (though we could use another name), as blue eyes, pink skin, pure white hair from birth, no freckling or partial pigmentation, dominant, may come from a single parent. Generally considered lethal if homozygous. (You are starting to convince me that partial pigmentation MIGHT not always be Sabino) Then there's SB-1, see my answer to your definition below (we are close) which I think is probably the most common "cause" of pure "white" horses. Third, there are other forms of "Sabino," what you call a "catchall," and I say is "real" sabino, just not fully understood. Best example are Clydesdales, most commonly recognized traits are the high white, bald faces, body spots extending up the legs onto the belly, lacy roaning near some white spots, etc. Arabians can have similar markings, note Khemosabi as an example. However, some people claim (and I'll go along with this, though grumbling all the way) that minimal sabino could be ANY white past the eyes, above the knees or hocks, or below the lip.

The mystery to me are "sabino-white" or "dominant white" Arabians, whatever you call them, as they don't have SB-1, they don't have "lethal" white (As in the CWH) and many have phenotypically solid parents, suggesting a recessive mode of inheritance, yet there are about 11 worldwide pink-skinned, brown-eyed Arabs with near complete depigmentation, and what's up with that?? Montanabw^(talk) 23:19, 11 June 2008 (UTC)

The most recent study on dominant white - Allelic Heterogeneity... - describes dominant whites as: dominantly-inherited, on the "W" locus (KIT gene), eyes are normal, "expressivity can range from ~50% depigmented areas up to a nearly completely white coat." This matches the definition of dominant white in other animals, namely pigs and mice. We should follow convention in an effort to be accurate.

This from the 2007 article you posted above? I'm Wondering if European geneticists and US geneticists are going off in different directions on this stuff?? This sounds like what UCD describes as "Sabino-white" in their stuff on SB-1. Either way, what DO you call the all-white horses with blue eyes and solid pink skin, to distinguish a "white" horse phenotypically from a horse that may have a W gene but not have 100% depigmentation? And what about that lethality issue in what has been called "WW"???

Nien, darling. UCD's website is oldddd. Ernst Bailey is at UKY and he's The Guy (if I got to be one of his grad students I'd probably...well...I don't know how to express that kind of excitement) and Samantha Brooks is with him and she's The Gal. I'll write more later, but I did want to point this out. Countercanter (talk) 00:32, 12 June 2008 (UTC)

Point #1. Franches-Montagnes = sabino? No. These horses do not test positive for sabino. So far only Walkers and MFTs have Sabino1. I'm not sure if Paints do. I've seen a Mustang that did test positive.

I'm thinking of the "sabino-white" Arabians that look like this but also don't have SB-1. Now, I'm pretty sure mustangs and paints have SB-1, not sure testing verifies it, but there is a whole class of pure white blue-eyed Paints they used to call "living lethals," not realizing that Sabino wasn't Overo. And mustangs have everything under the sun, depending on the band.

Point #2. Franches-Montagnes = gray? No. Owners of rabicanos and other extensive white markings describe patches that grow, too.

Hm. I always thought rabicano doesn't grow, at least not in the form I've seen it. It's a roaning pattern at most, and makes that "skunk tail" thing when minimum. No spots and minimal white markings.

Point #3. Franches-Montagnes do not represent dominant white. Untrue. They are a classic model of dominant white. Mau's 2004 Dominant White study was about the white FMs.

OK, but the example in the photos you provided was partially pigmented, that's all. To me, that's SB-1 Sabino-white, not "W" white, but if you explain it to me, I'm all ears. Would the partially depigmented horse possibly produce a lethal if bred to another white horse?

Point #4. One parent must be white to classify a foal as dominant white. Sort of. The term dominant does mean that a trait IS expressed in the parent. The claim that a white foal isn't dominant white if a parent wasn't dominant white is based on misunderstanding. Which came first, the chicken or the egg? These spontaneous mutations occur with *relatively* high frequency. That means that the rate of their OCCURANCE is greater than in the wild, regardless of selection. Our selection for temperament affects this rate; that is the "groundbreaking" part of the silver fox studies. Furthermore, such a definition doesn't take into account things like gene interaction: the sum of tobiano + frame is a horse with more white than a tobiano or a frame. This is true for other patterns as well.

OK, I'll accept that we may get spontaneous mutations (though I suspect people lying to the registry is more often the case! LOL!) But so how do you explain my "non SB-1 sabino-white" horses that come from two apparently solid-colored (or minimal sabino) horses that appear to each be carrying some less dominant - or even recessive - form???

Point #5. Dominant white must be lethal. Why? According to whom? Those who wrote the original studies, which were based on CWHs and FMs, made the observation that the trait appeared HZ-lethal. This was supported by similar discoveries in mice. However, let us not forget "viable dominant white" mice. This is not a criterion, but an observation.

The 2004 Mau study, for one (cite in White horse article). I'm open to the possibility that there would be non-lethal forms and more different genes at work than previously imagined. But there IS a lethal form, apparently, and to me that's one reason to be really careful about describing things -- Sabino, SB-1 as well as the "catchall" by whoever's definition, is apparently a form that does not have any lethal variants. Also, some people claim all lethal whites are just overos, that there is no "dominant white" at all, everything is either Sabino or Overo (I don't agree with that, but...)

Point #6. Dominant white horses have no colored skin/hair. Patently 100% untrue. You cite the CWHs as classic dominant white. All CWHs have the same mutation, but compare all of these CWH foals: [21] At least two have very visible distribution of pigmented hair on the topline. The others likely do as well but the photos are less clear. I remember the breeder of a dominant white TB stallion admitting that to obtain APHA papers, a small patch of pigmented skin had to be found, and was. Why this variability of expression? The 2007 study explains that cell workings have a method of pruning out "broken" proteins if they catch them called Nonsense mediated decay. Since these heterozygotes have a functional copy of their KIT protein, NMD may be clearing out enough broken protein to allow some pigment to form. The efficacy of this process varies; so does the amount of pigmented skin and hair.

OK, you got me that "Poema" sure is partially pigmented and maybe two others. (LOL). But we don't know what her parents looked like, no photos. I guess what's hanging me up is basically the issue of when a person is risking dead foals when breeding for "white," and when they are not. I just have serious issues with any type of breeding that deliberately risks a dead foal. That's my axe to grinp in all this

Point #7. Arabians do not have dominant white. Yes, they do. It is not the same as the Clydesdale pattern.

Proof? I see none. One horse claimed in a study to be "white," but no pedigree data. You will have to do some serious convincing of me on that one. Traditionally, it's been considered proof positive of crossbreeding, and the whole gist of the old white rule debate was the discussion of the form of Sabino that comes from Mesaoud and others, arguing that Sabino is a natural coloring that can be traced to desert roots, but that Arabians never carry any other overo, tobiano or "dominant white" (defining that as white in its lethal form) All the dozen or so "white" Arabians I know of are classified as "sabino", though not SB-1. Arabians NEVER produce lethal white foals, I've yet to see a pink-skinned and blue-eyed Arabian, and so far none have tested to have SB-1. But there is a whole "Sabino Arabian" so-called "registry" out there and there is something going on, whatever it's called.

All that said, I am open to being convinced otherwise, but I need really good evidence. Montanabw^(talk) 23:19, 11 June 2008 (UTC)

Point #8. Human error most likely caused the appearance of white TBs, because mutations are rare. There are several things to point out here. What has been found is not that white markings occur and are selected for, rather than against like in the wild, but that they show up more often and continuously crop up at a higher rate than they do in the wild, even before an animal would be subject to predation. The genes that are involved in determining brain wiring are involved in pigmentation. Furthermore, none of the Paints tested in 2007 for those KIT mutations had them. We can use genetics to determine when a mutation occured. This one family of white TBs is perfect. They have a gene; other white TBs from other families do not, nor do non-white related TBs, nor do Arabians white or non-white. That suggests that the gene popped up after the two populations were separated.

I'll buy the possibility of mutation for white (though not for overo TBs) and the white TBs do look really white and not Sabino to me. I'll give you that one! Montanabw^(talk) 23:19, 11 June 2008 (UTC)

In summary, let me suggest that we use the following terms:

• Leopard. A dominant white polygenic spotting condition. The phenotype is unique.

You are talking Appaloosa? Lp gene? Hm. Maybe. I agree with what it looks like, I question calling it "dominant white" and is it also part of the KIT locus?? Tread carefully. That's all. It's a weird gene with a lot of unique aspects, the striped hooves, the sclera, the mottled skin, etc.! You are not saying this could ever be a "dominant white" form, are you?

• Tobiano. A dominant white spotting condition caused by a chromosomal inversion that includes KIT/W. The phenotype is unique and rarely cryptic ("slipped tobiano"): concentric "rings" around the body of the horse when viewed from front or rear.

OK, need to align the geneticists definition with the APHA and Pinto registries ones, but no fundamental disagreement there. I'll trust you on KIT/W, as the details of the genome stuff are still a bit technical for me (what did "Bones" say? "I'm a doctor, not a mechanic?" I'm not a geneticist!) By the way, can Tobiano ever produce 100% depigmentation, i.e. a "white" horse.

• Frame. A dominant white spotting condition caused by a SNP on EDNRB. The phenotype is unique but may be cryptic: when viewed from the side, a frame of colored skin/coat is suggested, often with blue eyes.

Yes, as long as, to stay with colloquial terminology we call it "Frame Overo," and also address the question of lethal white syndrome -- particularly the claim that some "Frame" overos do NOT carry the LWS allele.

• Splash. A dominant white spotting condition of unknown cause. The phenotype is unique but may be cryptic: blue eyes are standard, horse appears to have waded through paint; smooth edges.

Now colloquially called "Splash overo," but yes, I agree with the basics. Also prone to deafness, right? Oh, and what do you mean by "unique" versus "cryptic?"

• Sabino. A dominant white spotting condition caused by a SNP on KIT/W. The phenotype is unique: hind leg stockings "gone wild" in heterozygotes, nearly all-white in homozygotes; blue eyes uncommon; rough-edged, blotchy/roaning.

Agree as to SB-1, (and again, what is an SNP?) but may also be other forms called "Sabino," traits include this APHA definition] lists most forms. But UC Davis says, "Other breeds of horses that are known to have sabino patterns, such as Clydesdales and Arabians, have so far tested negative for the Sabino1 mutation, although the number of animals tested is low."

• Rabicano. A dominant white spotting condition of unknown cause. The phenotype is unique.

Nope. Well, maybe dominant, but not "spotting," Unless you also call roan "spotting." Do we have ANY research on what IS causing Rabicano? It's a roaning pattern, but not true roan. (Now, I know Roan also has some connection to KIT?)

• Dominant White. A series of dominant white spotting conditions all SNPs on the KIT/W locus. The phenotype is not unique: coats range from 50% to 99% pink-skinned white, with brown eyes.

Maybe, as to "a series" of different patterns, but what do we call the homozygous lethal forms, then? -- particularly so as not to confuse with lethal white syndrome? And linked to one specific gene or several suspects?

• White Pattern. Catch all for any other white marking or pattern. This is accurate from stars and snips (note such markings are called white spotting in mice!) to huge high whites and other, unidentified "whites", and ticking, etc.

Nope, those are "white markings." (grin) But I otherwise can agree on the defintion. Whatever they are genetically, to call them "patterns" per se is to depart too far from traditional horse terminology, and horse people do not care what they're called in mice. We have a term of art issue here. I don't want to reinvent the wheel. I know, the line when something stops being a marking and starts being a pattern lives somewhere in the Sabino family, but I am not going to go off and create a new synthesis that challenges the entire horse community -- yet, anyway! (cluck, cluck, cluck, yes, I'm chicken...) Montanabw^(talk) 23:19, 11 June 2008 (UTC)

We are getting closer here. I'm really finding this fascinating, believe it or not! Montanabw^(talk) 23:19, 11 June 2008 (UTC)

Let's see how far this gets us in our discussion. Countercanter (talk) 15:01, 11 June 2008 (UTC)

Housekeeping

06.09.08: removed old discussions.

To Do: Contribute to Babolna stud.

Draft breeds: Oberlander Horse, Rhenish-German Cold-Blood.

Anglo-Arabian breeds: Pleven (horse), Kisber Felver, Anglo-Arabian, Gidran

Riding Horse breeds: Kinsky horse, Czech warm blood, German Warmblood, Hungarian Warmblood

Colors: Pearl gene, Black (horse), Chestnut (horse), Equine coat color, Cream gene, Cremello, Champagne gene, Dilution gene, Dun gene, Splash white, Lethal White Syndrome, Color breed, Tobiano, Overo, Sabino horse, Leopard (pattern), Cropout, Smoky black and smoky cream

Others: Collection (horse), Lead change, Canter, Impulsion

Countercanter (talk) 11:47, 9 June 2008 (UTC)

FYI, Spash white is explained in the Overo article, as is frame. Someone (anon IP) just added a red link in the pinto article too. For now, I'm going to redirect the spash white red link to the overo article until there's enough to break it into its own. I also think that leopard (pattern) needs A LOT of help, partly because it tries to be about all animals. Similar problem in Piebald (and if you want more articles on your wish list, see Piebald, Skewbald and Tricoloured (horse).) Montanabw^(talk) 00:56, 11 June 2008 (UTC)

UCD, WP:V and other hiccups

I have heard complaints that UCD's stuff is outdated before (They took down their "New Genetics of Overo," which was from the 90's, but it's still out there elsewhere, and the Appaloosa article dates to the 80's, I think). But it's published and on the web. Trouble is, a lot of newer stuff is in hardcopy or not yet published in scholarly journals (what's the lag time, like six months to a year for peer reviewed journals?? I know a guy whose article was finished, submitted and he literally DIED before it finally hit print!) and is sort of summarized at best in half-accurate fashions on blogs and chat boards. (whining). I know the gang at UCD are kind of hot on the tail of the dilution genes at the moment more than anything related to spots. (Or genetic lethals, for that matter, which is my thing, and I have had dealings with them on this directly, AND dealt with some less-than-organized people...grrr...feel free to email me if you want the whole tale of woe!) Cornell pretty much beat them to the HERDA test, I think, though they graciously shared credit.

But griping about the shortcomings of UCD aside, the problem is that we need verifiable sources on Wikipedia (per WP:CITE and WP:V), especially given horse poliltics (particularly on lethal whites in whatever fashion) and so we need published stuff, ideally stuff that can be verified by other users without racking up fees of $30 per article (sigh, grumble!) ... I am cool if there are successors to Bowling and Schoenberg (sp?) but isn't Bowling's treatise on horse genetics still one of the more recent ones? And she died in what, 2000? I'll trust you on scans of articles like the one you posted, and also trust you on direct quotes from scientific literature that may be published in hardcopy, but we need to be careful to be sure we are quoting others in proper context and not our own synthesis of research (per WP:OR). It's a PITA (pain in the A--), but the whole process of surviving not one but two GA reviews and re-verifying everything in Arabian horse to get it ready for FA is teaching me some hard lessons about wikipedia standards that has been hard on the ego, but probably good in the long run. (And I STILL hate the citation templates!) Montanabw^(talk) 22:52, 12 June 2008 (UTC)

Oh, and if you want your head to explode (mine almost did), read the color section in Fjord horse. They are all duns, but don't say that to the Fjord people, who have their own special names for everything. I did the rewrite when a Fjord person kept changing things to say they came in "gray", which is what Fjord aficionados call what the rest of us call blue duns or Grullas. =:-O (And by the way, any idea what the heck causes those striped manes? Could they have some sort of rabicano thing going on, or does the dun genome have room for the skunk look?) Montanabw^(talk) 22:56, 12 June 2008 (UTC)

See? His mane is long and he looks like any other pale bay dun.

Most duns have what are called "frosted" manes and tails [22] See? What is effectively happening is that the dorsal stripe is bordered by contrasting paler hairs. We also see this in zebras (check out the title guy's dorsal stripe). Plains Zebra also exhibit this trait to an interesting degree. If you look at the photos - these guys are similar to the Quagga - you can see that oftentimes they show the underlying brown coat in what looks like intermediate stripes. One way to think of it is that the zebras are like any other wild equid, but that their vertical black stripes - like those seen in some duns - are close enough together that the white guard hairs run together and cover up the underlying "bay dun + pangare" common to other equids.

[23] More examples.

So is a zebra white with black stripes or black with white stripes? Neither! :) I have no sources to prove this but Genes Are Conserved. Anywho, in Fjords, that trait is heightened by the shaving of the manes and the presence of pangare. When their manes are long, they look normal. The pangare also, incidentally, seems to cover up the leg markings. PS, if "brindle dun" popped into your head, you're not alone! :) Countercanter (talk) 00:39, 13 June 2008 (UTC)

Great fun! IN QH land, I wouldn't say "most," though I would say "some." (grinning) (Most famous dun QH in the world, no white hairs) And I do wonder if in light riding horses if that is actually some sort of rabicano influence? (Again, Arabians don't carry dun AT ALL, but they do express what some say is rabicano by the light hairs in the mane and tail, the "skunk tail" look) IT is certainly more marked on Fjords,I do agree--but is it just the dun gene, or is there something else going on? But oh dear, you reminded me, we also have Pangare (which, as you see needs an article, want to do one, as you did for Sooty??) And oh man... What's your theory on THAT? Had a huge fight with someone who claimed it caused the lighter muzzles on all "brown" (sooty bay) horses. Oh yes, and the famous alleged "Flaxen gene" in some chestnuts, that breeders love to claim they can produce, except they can't (other than Haflingers, who all seem to have it) and no one can seem to figure out? Montanabw^(talk) 22:18, 13 June 2008 (UTC)

Look more closely at the Famed One and you'll see those guard hairs! ;) 22:44, 13 June 2008 (UTC)

Micro-freaking scopic! LOL! How do you know that's not just sunburn!  :-P Actually, no biggie to me. (grin) More to the point, I actually am more interested in what causes the similar "skunk tail" thing that gets called "minimum rabicano" in non-duns -- Bay Arabs seem to have it a lot. I cannot for the life of me get why a skunk tail and center-of-body roaning can be linked to the same process. Illogical to me, but the breeders claim it. (I think you and I share a frustration with breeders who make unsupportable claims about color, like "throwing black.") Montanabw^(talk) 22:59, 13 June 2008 (UTC)

Well I *said* you had to look CLOSELY. :P Ticking is interesting. But as before, Genes Are Conserved. As you can see from the roan dog section of the article, it's proving very tricky to sort out. If you asked me for my opinion, I forecast that ticking/roan in dogs will prove very similar to the leopard complex. In dogs, ticked/roan is ONLY expressed in WHITE areas. In Lp horses, this is also the case: the big spots (in hets; homozygous Lps have liiittle spots) are found in the middle of large regions of white that are genetically controlled separately. The deafness of Dalmations isn't due to the roan/ticking, but to the parallel of maximum white. Dalmation spots, which are big and well-defined, are visible on the white areas, which happen to be all over. In cats, ticking is caused by something else entirely. It's related to agouti rather than distribution of white. Cats and mice (and dogs, I imagine) have "Chinchilla" type coats that are also I believe agouti-controlled; the hairs are pale but tipped with black. Chinchilla in mice is described as "reduces the yellow in agouti coloration, and slightly reduces the black" so is actually analogous to cream. I'm rambling. But [24] here is a SUPER awesome page on mouse markings. Ednrb = frame, btw! It beautifully shows the Dominant White complex, explaining that homozygotes for *any* of those conditions produce black-eyed-whites and seem to be lethal, but that pairing two or more different conditions can produce viable black-eyed-whites. I'm sure all this sounds familiar. BTW, have you noticed that frame and splash are associated with blue eyes, and the others are not? There is a reason for this... :) So no, I have no idea what causes rabicano. We have 3 or 4 red rabicanos at my barn...all ponies. Hoping to get photos of them stood up with our bay roan!

PS, the way to tell rabicano from dun guard hairs is that guard hairs aren't always/usually stark white. Dun and its signatures are part of the wild type condition, and since pigment's first role is to protect cells from radiation (from the sun), a wild type condition ought not contain true, unpigmented white. It might take a microscope or an NMR to tell for sure if pigment is in the hairs though. Rabicano is a depigmentation pattern; those hairs should be true white. If I recall correctly from hosing down our rabicanos, the white hairs are associated with pink skin. I will check to make sure, and take photographs at some point over the summer. The conundrum is that since rabicano is so closely linked to other white spotting patterns, can one safely chalk up pink skin to rabicano? [25] Here is an example. Black rabicano Arabian; mottled skin under rabicano roaning.

As far as white ticking that has its epicenter just aft the stifle, but also affects the base of the tail...ya got me! I'm sure that someone more familiar with developmental processes could tell us. Then again, with frame part of the confusion is that we don't automatically associate the colon and the coat!Countercanter (talk) 12:34, 14 June 2008 (UTC)

See, I think it's not as closely connected as you do, perhaps. Mice studies are interesting, but I wonder how these will translate to horses (or dogs, for that matter). Just being associated with the KIT locus to me is sort of like all sorts of different houses on the same street...The Rabicano Arab in the Rabicano article doesn't appear to have skin mottling, but I suppose you mean only under the white ticking? I've seen so few of these, but the one that boarded at our barn had virtually no white markings anywhere else, and if he did have pink mottling under the roaning, well, if it's only visible when wetted down, we didn't -- the "skunk tail" rabicano Arabs I see have blondish-hairs, usually are bays, the roaned-out ones more often seem to be chestnuts. But as for the skin thing, roans are solid-skinned, so...? By the way, what IS your take on why the one form of "dominant white" (WW, not LWS) is lethal, but not Sabino forms?? Montanabw^(talk) 06:13, 15 June 2008 (UTC)

I beg your pardon, but you are mistaken. This gene is ancient. I looked up the proteins coded for by this gene for mouse and horse and used a protein alignment tool to see just how similar they are. Over 80% identical. The notion that genes are conserved is so vital to understanding genetics. Unfortunately, we will have to leave it at that, and in a few years I think it will become clearer.

[26] This is the protein alignment tool, and I will happily instruct you how to align proteins or nucleotides (protein codes are 1/3 the text length) so that you may see for yourself.

As far as the rest of the content of your post. Chestnuts express white more readily than eumelanistic horses. I do not know why. Actually, white markings are more pervasive on the left legs than right. Isn't that odd? I will hopefully photograph Penny on Tuesday. Roans are solid-skinned and I haven't got a darn clue why that is. But that's got nothing to do with rabicano.

Summarized from the article...Homozygous lethality occurs when the protein affected is irreparably "broken" by the mutation, and the protein is vital to survival (EDNRB is necessary to nerve formation in the colon, KIT is necessary to the production of white blood cells). Tobiano and sabino-1 do not break KIT because tobiano causes KIT to read backwards and sabino affects when/where it is read; tobiano and sabino-1 affect regulation of KIT, not KIT itself. Of the four known dominant white alleles, the one found in the FMs and the one Arabian family seem to truly break KIT. Entire sections of the protein simply aren't made. And the protein is necessary to survival. The authors also said, though: "[The foundation of the] report on the embryonic lethality was derived from the analysis of offspring phenotype ratios in a single herd segregating one or more unknown mutations. As there is now evidence for allelic heterogeneity, it remains to be proven whether all equine dominant white mutations cause embryonic lethality in the homozygous state. While this is certainly likely for the two nonsense mutations found in Franches-Montagnes Horses and Arabians, it should not necessarily be assumed for the two reported missense mutations or for any of the other as-yet unknown W mutations."Countercanter (talk) 13:55, 15 June 2008 (UTC)

Oh, white markings are ancient and linked to domestication, I get that. But on the other hand, their appearance in TBs appears to be pretty recent. BUt for the rest. By "Break KIT" do you mean inherently lethal? (Just want to clarify) But is the FM allele seen in the "lethal whites" that show up in American horses, like the CWH's and such? While it's sure true that most of the "lethal whites" that had people panicked here were Overos, there does seem to be another that isn't linked to spots. And oh please god, don't tell me there is another lethal allele in Arabians now...are you SURE they aren't describing lavender foal syndrome? Seriously. These "white" horses cannot possibly be purebreds unless we are talking a recent mutation in the last few years - which if it's one family, could be true. I really would be extremely interested in seeing pedigree data. Any idea where they have it? (Probably locked up like Fort Knox) This has not been something that has hit the news in the Arabian industry and would be absolutely explosive if it is true.

So, what's your take on the "lethal roan" question. Seems like the science is all over the place-- your study notes it, but from a 1979 article, Bowling claimed to have disproved it around 2000 or so. And if Roan is linked to KIT too, then what the heck IS rabicano...?

As for lining up the sequences, I'll trust you on that one, I wouldn't know what I was looking at, I'm a lawyer, not a geneticist! LOL! Evidence, I am seeking evidence...I let the experts explain it, I translate the expert interpretations into English once *I* get it. Sort of! LOL! Montanabw^(talk) 20:24, 16 June 2008 (UTC)

Chestnut

Whoops! An edit conflict again! I'll work your tweaks back in, give me a sec. Be out of the article in 15-20 min, then you can fix everything I screwed up! Montanabw^(talk) 22:04, 16 June 2008 (UTC)

Beautimous!Countercanter (talk) 01:21, 17 June 2008 (UTC)

New food for thought

Nice work on the chestnut genetics, by the way, but may need to wikilink to more of the genetics terminolgy. Anyway, totally unrelated (or maybe somewhat related) to all of the above, here's the conundrum that has been puzzling me for a few years: The depigmentation process in aging horses who have no apparent reason for it. I have an old dark bay ("Brown") mare who is 28 (Purebred Arab). (in photo, you can't see the white hairs really, the resolution is too poor, but you can see her base color. She also dapples) Her dark bay sire, who had very little white other than a big white snip on his nose, had one faint body spot that the Sabino fans claim indicates the presence of a sabino gene. Her dam was a gray. FWIW, there were six full siblings from this cross, three dark bays, two grays and a blood bay. All with very little white. My mare has had a few gray guard hairs at her throatlatch and a small white spot at the peak of her sacrum for many years (but not from birth). But starting in her early 20's, she began to have more little gray hairs every year, mostly on her upper neck, but also in her tail, on her face, etc. This year, her neck is quite noticably flecked with white hairs, and she now has faint white hairs right at the bottom of her flank, around her jaw, a few white hairs around her white spot on her spine, and a few white hairs by her elbows--but most noticable on her neck. In contrast, her 1/2 sister -- with the same sire and a bay dam -- is 25, has zero graying/roaning anywhere. So what do you think we have? Depigmentation due to age-related graying, some sort of sabino thing cropping out...? Curious... Montanabw^(talk) 04:50, 18 June 2008 (UTC)

No clue but very interesting! There are so many processes that could be at work. Also I heard rumor of a brown test. I'm looking for more information. [27] Here's the link to the lab that developed this test. Hopefully that information page will be up soon. Countercanter (talk) 12:23, 18 June 2008 (UTC)