Off-Color Coat Research

anne · Posted: Thu Aug 11, 2005 12:26 pm Post subject: Re: colouring of the breed

By the way GrayGhost, if you have any information on off-colored Weims I'm doing some research on it and would love to talk genetics with you.

Thanks for the welcome!

Just to clarify, I'm not referring to Blues when I say off-colored.

GrayGhost · Posted: Thu Aug 11, 2005 7:39 pm Post subject: Re: colouring of the breed

anne · Posted: Thu Aug 11, 2005 7:58 pm Post subject: Re: colouring of the breed

Rusty Jenrette wrote an article in Dog World back in the 70's which discusses this. Also in a WCA mag from back in the 70's there has been a report of a black (not blue) being produced from 2 grays. Jack Denton Scott's book also has an article in there which references black Weims. I have also personally seen pictures of a creme colored Weim. Was it purebred? Don't know. The papers said yes. This was a rescue dog and the ped was tracked to a breeder that has produced it before. And believe it or not, have seen a Vizsla colored Weim also purported to be pure (and did look like a Weim not a V) and am waiting for a pedigree on that one.

People lie about pedigrees and can put false info on one and submit. All these "off colored" Weims are surrounded by issues of whether they are pure or crossed........ There are no answers......

It's certainly possible to speculate how it COULD have happened genetically.... Articles by Jo James shows how it could be possible, but also she speculates that it's the Blues the caused these colors (she believes in the dobe cross theory about Blues) and when you follow her genetics, yes, it could happen that way.

I'll check out that site, thanks.

Anne

PS - No, not talking about dobe marked either, as this is a simple genetic explanation and is proven to be inherited recessively. I'm talking about the truly "weird" colors.

GrayGhost · Posted: Fri Aug 12, 2005 2:10 am Post subject: Re: colouring of the breed

That is very interesting. Some of those "could" conditionally be explained with recessive genes, with one catch, the dilution (although IIRC cream is believed to be a dilute color in some breeds).

Do you have any ideas how two dogs that are homozygous for dilution could produce undiluted color? If you figure that out, the rest should be a lot easier to explain, at least genetically.

The tough part would be proving whether they have been there since the conception of the breed, or more recent developments that have been recently "added" to the gene pool.

anne · Posted: Fri Aug 12, 2005 1:11 pm Post subject: Re: colouring of the breed

Jo James believes that there were Weims with the silver coloring that were actually D. I have to find the article to give you all the genes she believes contributes to the dog in order to make a dog appear silver even while having a D. Not sure what I believe about that.....

(Duh I just realized that the post I thought I 'lost' was on a different thread.)

GrayGhost · Posted: Fri Aug 12, 2005 3:20 pm Post subject: Re: colouring of the breed

anne · Posted: Fri Aug 12, 2005 7:47 pm Post subject: Re: Off-Color Coat Research

Here is what Inhertiance of Coat Color in the Weimaraner by Jo James says (among other things, I really need to get this whole thing scanned)

ay ay E- bb D-
Sable liver full color. A light dog of thisgenotype might pass in the show ring. Nose gene would be full iver, but nose color genes could be damanged giving light nose and eye rim, and lip coloration could go unnoticed. The presence of dark eyes would indicate this geotype, but if yellow eyes were present (as in many full blacks and livers), this genotype could be accepted. This dog bred into other lines could produce pureblakcs, pure livers, or yellows, this occurence is common in the hisotiry of the breed.

ag- E- B- Dd
ag- E- bb D-
Agouti Black and Agouti Liver full color. SOme of these fully colored dogs could pass in the show ring if they had yellow eyes and the nose cells were dmanaged. Possibly the full black lips, eye rims and pads (or liver) might go unnoticed. These dogs could produce litters of full blacks, full livers etc when bred into other lines

Speaking of the D-genotype, she writes:
D-genotype also occurs in the Weimaraner. IN the B-D- genotype, the existence of pure black in the nose, eye rims, lips and foot pads is usually obvious and selected against. In the bb D- genotypes the true determination is more difficult. The pheotype of the liver sable or liver gray agouti with a light liver or suburned liver nose would be hard to determine from the dilute liver. Light amber or yellow eyes can occur in the non dilute dogs, but a true dark eye cannot occur with dd, thus the existance of a dark gray eye in a Weimaraner might indicate a D- genotype.

The D-genotypes when bred into a genotype carrying B- or that is recessive to that type of D- (genes at ohter locus) could and has produced litters of pure blacks, pure livers, or mixed litters.

In all other breeds where a dominant black coloration is interbred with a liver recessive, Laboradors, Flatcoats, Cockers, etc., the heterozygous Bb shows incomplete recessive, of the B allele over the b. Partial dominance manifests iteself in "off" colored shadings or rusty tippings at certain times in the coat. This partial dominance is probably present in our heterozygous dominant blues and the expression of such, well known to our Blue Weimaraner breeders.

There is a lot more to this article.... She also says that Weims do carry Irish spotting and piebald. Most other articles I have only consider Weims to have S and none of the recessives (Irish spotting, piebald, extreme piebald etc)

anne · Posted: Fri Aug 12, 2005 7:51 pm Post subject: Re: Off-Color Coat Research

<<I am just taking a stab in the dark here, but I am guessing that the theory is based on the supposed slaty/DCT/TYRP2 (Dopachrome tautomerase) gene?>>

There is no date on the article, but knowing when she was active, her article pre-dates this finding, so it wasn't considered in her article.

GrayGhost · Posted: Sat Aug 13, 2005 1:01 am Post subject: Re: Off-Color Coat Research

What an extremely interesting article. What is interesting to me is this initially mentioned genotype (ay ay E- bb D-) can be found in GSPs (at least EE and DD and perhaps more). I could see from this theoretical genotype how livers and yellows could be produced without a doubt; however I do not understand the conclusion that this could produce black. That is unless she is taking blues into consideration, then this would most certainly be possible. And in addition, depending on the Int genes present in the current Weim gene pool, various shades of red could be produced. And if there is a recessive chinchilla gene in the (Ccch) Weim gene pool, creams would also be quite possible.

We normally assume that there aren't a lot of recessive genes (short of the Agouti "dobe" markings), but given the Weim's coloration, there are quite a few recessive genes that could be in the Weimaraner gene pool that wouldn't normally effect the phenotype. I mean, unless I am mistaken, a dog that was cchcch would still be a perfectly silver dog. And given that it is common knowledge that there are various shades of "silver gray" and Int gene could be in play as well.

Now with this in mind, this gives the possibility of various shades of red, especially with if there is an Int in play, and possibly even creams, and all from silver gray dogs. And from what I am reading, she believes that a diluted red variant would be nearly indistinguishable from true silver gray and will fall within the normally accepted range of silver gray (I am guess it would have a shade like the body of a fawn/Isabella dobe).

But from what I have read so far, nothing here supports that a black could be produced from two true silver grays (bb dd). You could get a black from a light liver and a blue without a doubt, given the information here. However it seems she theorizes that there are dark eyed gray Weimaraners that might be Dd, thus giving the possibility of these dogs producing black. In other words, I believe she thinks that some blues/darker grays (darker eyed) are not actually dilutes based on eye color. Admittedly, I have seen both dark gray and yellow eyed blues myself.

It also appears that some Agouti blacks and Agouti livers with pigment damage and yellow eyes might be able to pass, but this seems a stretch to me...

Now in reference to the dark eyed grays; there IS currently believed to be another unknown diluter in dogs that is NOT the D/MLPH gene, as speculated by Sheila Schmutz, as I am sure you have probably read about. If not, this site, and this individual may prove invaluable to your research: http://skyway.usask.ca/~schmutz/dogcolors.html This website also contains many links to other coat genetics websites that I think you will find helpful.

In the cases of off-colored Weims being purportedly produced from silver gray parents, I think it would be extremely interesting to test the offspring and the parents to reveal exactly what they are, as I have my doubts that they are (bb dd), but looking back, there may be other interesting possible explanations how two Weims with similar phenotypes could produce off-colored coats.

I really have to say Anne, this is some of the more interesting stuff I have read in a while and has really got me reading more and more about other genes that I hadn’t previously considered. Thank you for sharing!

anne · Posted: Sat Aug 13, 2005 2:37 pm Post subject: Re: Off-Color Coat Research

Exactly ----

She says that bbdd is the most common but in the past there were others with D- that passed for the "correct" color and therefore there are occasional reds, cremes, livers, etc. She has also told someone I corresonded with that it's because of the Blues being dobe crossed (not proven, but what she believes) B- was introduced into the gene pool and therefore there are Blacks.

Still..... I have seen other documentation that occasional blacks predates Casar von Gaiberg. I need to look back at Scott's book to see what the date is on the article discussing black. Actually it was a black LH.

I emailed Sheila Schmutz some time ago to clarify some questions I had when I read Jo James articles because I'd been toying with writing up something about Weim coat color genetics for a website I'm planning (on Blue Weims) but decided to just stick to the Blue coat coloration since for one, Blue vs Gray is so simple to understand, and there was just too much for me right now to write up something on other colors. As it is, it's still taking me over a year to do my Blue info site. So might be a project for later. Which is why I was interested in discussing these ideas with somoene else, there are still definitely questions, and it's been a while since I visited these issues, so would have to do a whole review of websites and articles. And in the end..... there will be no answers anyway. I suppose no one can really say for sure that all these examples of off colored Weims happening aren't just cross breedings.