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Post by aktyson on Feb 25, 2006 5:46:32 GMT 1
Does anyone know the genetics of white markings in Weims? For instance, if you bred two non-white marked dogs together that both have white behind them and both have thrown small amounts of white (non disqualifying) would you get merely a greater percentage pups with acceptable white or would you be likely to get disqualifying white?
TIA
Anne
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Post by marjolein on Feb 25, 2006 10:13:32 GMT 1
Hmmm, I'm not for sure, but I don't think this is very likely to happen.
All I do know for sure, is if you try to breed out the white completely, you'll very likely end up with purple-ish Weims.
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Post by Pasquinel on Feb 25, 2006 10:42:44 GMT 1
Hi I don´t know that much about the genetics of white, I also wonder a lot about it. In my C-litter I bred our Gosan to a male without any white, Gosan has a little spot. All of the pups has small markings but one bitch ended up with a big big mark on the chest. The male has Arokat´s Legionnarie in his 3 and 4 generation and I wonder if it´s from there she got the big white ? My Gosan is from German lines and of course she can have it also , I haven´t seen photos of that many in her pedigree. Does any body know if there is any big white marks on her relatives ? Here is her pedigree www.pasquinel.se/stamtavlor/gosan/gosstam.htmAnd here is the bitch that has the big mark, I think it looks very similar to Arokat Legionnaires mark. regards Kristina  |
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Post by aktyson on Feb 25, 2006 19:33:55 GMT 1
I've done some research and will at least partially answer my own question.
Page 93 of Weim Ways explains basics of the genetics of white. Basically all Weims are homozygous SS for solid color. The S genes are influenced by modifiers (also inherited in pairs) that are coded +/-. These modifiers effect the white patches we see in Weims. Plus modifiers = more dark pigment and minus modifiers = less dark pigment. So from this analysis I suppose if a pup were to inherit two minus modifiers they could get large patches of white. The continuum of white patches runs from solid dogs, to small chest patch, to small chest patch/neck patch/one or two white toenails, to large chest
patch/neck patch/belly patch/white toes, to peudo-Irish pattern (white patch running underneath the dog from neck to belly to sheath).
The S modifiers are also influenced by environmental factors - prenatal conditions (age of dam, uterine environment, season of the year). Identical twins will not have identical white patterns.
I may be wrong in my thinking but since the prospective sire & dam are both solid they likely are heterozygous for minus modifiers. So the litter should have 1/4 solid, 1/2 some white and 1/4 greater amounts of white. Of couse it will depend on the environmental factors also. Please correct me if I have anything wrong.
Anne
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Post by daniela on Feb 25, 2006 20:02:58 GMT 1
How does that work? I have never heard that before. Do you mean a purple-ish colour in coat or pigment?
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Post by daniela on Feb 25, 2006 20:23:53 GMT 1
As a side note, today in the UK, I rarely see Weimaraners with white and if I do, it's normally a few hairs or a very small spot on the chest. I still see the white spurs but they are always harder to detect with casual observation.
That's not to say that there are no dogs about with white on their chest, just merely an observation of dogs in the show ring today. Going back 15-20 years or more, there was a lot more dogs being shown with larger splashes of white.
All the dogs we have owned within the last 15 years have not had any white. In that time, we bred about four litters, with around 40 puppies and out of those 40, two had white on their chest.
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Post by marjolein on Feb 26, 2006 12:11:06 GMT 1
In France, they have been trying to breed out the white completely, for years. I've never seen one myself, but I've been told by several people, French peeps too, that the Weims from these lines have an aubergine/grey coat colour. Too dark according to the breed standard.
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Post by daniela on Feb 26, 2006 13:10:23 GMT 1
I have never seen one either. I wonder whether they just mean a darker shade of grey. In which case I have seen lots of Weimaraners with a darker grey coat but I wouldn't classify it as being too dark for the breed standard.
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Post by aktyson on Feb 26, 2006 15:47:32 GMT 1
I'm curious why any breed organization (or any breeder) would want to reduce the gene pool for a completely harmless trait? Besides some white is perfectly acceptable by all breed standards I've read. What is the breed standard in France?
Anne
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Post by daniela on Feb 26, 2006 17:11:35 GMT 1
Maybe they figure that if they use a dog with white and/or a bitch, they increase the chances of a small white spot becoming a big splash or more  FCI breed standard for colour: COLOUR : Silver, roe or mouse grey, as well as shades of these colours. Head and leathers generally slightly paler. Only small white markings on chest and toes permitted. Sometimes a more or less defined trace occurs along the back. Dog with definite reddish-yellow marking (« Brand ») may only be given the classification « good ». Brown marking is a serious fault. |
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Post by marjolein on Feb 26, 2006 20:50:51 GMT 1
Well, there are people on the forum who absolutely hate a white mark on the chest, no matter how small it is. I think there are some people in France too, who think the same way.
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Post by aktyson on Feb 26, 2006 22:32:27 GMT 1
"Maybe they figure that if they use a dog with white and/or a bitch, they increase the chances of a small white spot becoming a big splash or more"
Good point. But that's where the genetic research comes in. . .
With what I've found 3/4 of the litter is likely to have either none or completely acceptable white. There is a chance that 1/4 of the litter may have disqualifying white. A big white patch never killed dog. Nor made them ill. Nor hurt their hunting abilities. In theory, bred back to a homozygous plus-modifier dog you could reduce that white to acceptable for an entire litter in one generation.
Now if I'd learned that it would be likely that the entire litter or most of it would have disqualifying white and that it might take many generations to breed away from disqualifying white my decision might be different. But as things stand I'll go forward with the mating.
Anne
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Post by marjolein on Feb 27, 2006 10:18:29 GMT 1
Of course Anne, I don't really care about white spots either. As long as it's not too big. I think there are more important things in Weims than white spots.
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tasha
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Post by tasha on Jul 4, 2006 13:32:34 GMT 1
dog with a white mark usually have that lovely metallic light grey coat... its sought after in the uk because our coat colours are getting dark or are a sort of pale beige. I'd look for a dog with a small white mark because my bitch is very dark.
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Post by Weims on Jul 9, 2006 17:19:15 GMT 1
My Bitch has a white mark on her chest but you can really see it until she rolls over. She is the metallic silver and in the sun her coat is magnificent. She came from parents who had no white at all, neither had the grandparents on either side. In that litter was a dog who had a large white patch and he was a lovely shape and length for showing but I sold him to a pet home because of the white patch.
I agree with Tasha about the dogs in the ring being dark or the beige colour.
Lynn
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tasha
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Post by tasha on Jul 10, 2006 18:18:19 GMT 1
I saw a beautiful bitch at a training day on conformation and she was the colour that I was looking for but rarely find, as a golden oldie her coat was in beautiful condition. Thankfully someone very kind sent me her details so I'm off to look up her pedigree and see if I can find dogs of her line.
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