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Jenn~n~Luke
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01-10-2011, 09:39 PM
I must say...while I do like the look of the crop on some danes, mostly males, somehow on a female it makes them look more masculine to me, not always but most of the time...but I could never do it. I just can't justify that kind of procedure for looks alone. The thing that ticks me off is that here and in the US, more so in the US I've heard, there are still some judges who will pick a cropped dane over a natural, even if the natural one is actually the better of the two. That kind of thing is one of the problems I have with the show world...
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Jenn~n~Luke
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01-10-2011, 09:41 PM
Actually as far as I know he could have gotten that pattern from having one parent be a black from harl breedings, with the other being a harl or a merle. Also could have come from harl/harl matings.
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Sara
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01-10-2011, 09:44 PM
Cropping is horrid. I once got into a debate over cropping with a dane show person. one of her responses made me sick. "I feed them, give them a nice place to live, couches to sleep on and love and cuddles... least they can do for me is to get their ears cropped."

Like the dog thinks that way! idiot!

I actually dont like the look on danes, and I hate the look on boxers, pitbulls and mastiffs... the only dog I think it looks good on is a dobe, but the procedure is so cruel, that I hate seeing it.
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Tassle
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01-10-2011, 09:48 PM
I loves his ears. He is apparently from one of the top show breeders in this country - I would highly doubt it was a harl/harl mating (But could be wrong)

I am not a fan of cropping - i cannot understand changing such wonderful soft pullable ears!!!
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Sara
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01-10-2011, 09:48 PM
Originally Posted by Jenn~n~Luke View Post
Actually as far as I know he could have gotten that pattern from having one parent be a black from harl breedings, with the other being a harl or a merle. Also could have come from harl/harl matings.
Harle x harle will not have merle in it, as far as I know, but I could be wrong... I'm going to look into it. Harle is dominant like Merle, so if the dog has the harle gene, then it'll show harle, so a black would not have a merle pup unless the father was merle, and even then, wouldn't show like a double merle. but even there I could be wrong, I'm going to look it up as harle is tricky as it's a derivative of merle.
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Jenn~n~Luke
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01-10-2011, 09:53 PM
I know its so bloody confusing but I have seen matings where reccessive genes have thrown odd colors. For instance, the moderator of Danes online has a rare tan and black dane, from blue/black parents. Another breeder here in canada had two blue fawns crop up out of a blue/black breeding...somewhere back in the lines there was a dog that carried for fawn.

Technically merlequins are double merls, the "quin" at the end refers to the pattern of colors, the merle refers to the color itself. Make sense? Instead of black patches you'd see in a harl, you get the merle patches.

Unless you breed from very strict lines that have stuck to the proper color matings for generations, you can get some wild colors coming out in your litters. I've seen rainbow litters from breedings where the parents were both the same color. It's all there in the genes somewhere.

http://www.chromadane.com/harlpatterncolor.htm
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Jenn~n~Luke
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01-10-2011, 09:56 PM
Abstract: Harlequin is a pigmentary trait of the domestic dog that is controlled by two autosomal loci: the melanosomal gene, SILV, and a modifier gene, harlequin (H), previously localized to chromosome 9. Heterozygosity for a retrotransposon insertion in SILV and a mutation in H causes a pattern of black patches on a white background. Homozygosity for H is embryonic lethal. Fine mapping of the harlequin locus revealed a 25kb interval wherein all harlequin Great Danes are heterozygous for a common haplotype. This region contains one gene, PSMB7, which encodes the ß2 catalytic subunit of the proteasome. Sequence analysis identified a coding variant in exon 2 that segregates with harlequin patterning. The substitution predicts the replacement of a highly conserved valine with a glycine. Described herein is the identification of a naturally-occurring mutation of the ubiquitin proteasome system that is associated with a discernable phenotype of dogs.

HARLEQUIN GENE DISCOVERED!

Dr. Leigh Anne Clark and colleagues at Clemson University have recently discovered the gene that causes the Harlequin phenotype & publication is pending. The discovery is a most interesting one, as it turns out the harlequin gene isn't a "color" (pigment producing) gene at all. The harlequin gene simply alters the affect of the merle gene, so that the diluted regions (of merle coloration) otherwise seen are largely removed from the coat pattern, leaving behind the bi-color dog we know as a Harlequin.

So there is now proof positive that all Harlequins are genetic merles. The old notion of a "modifier gene" is still basically correct & helps the layman understand the interaction of harl and merle alleles: the "harl gene" acts on dogs with the merle mutation to produce a novel phenotype by "taking the grey out" (i.e. removing most all of the diluted pigment we call merle). Harlequins essentially are a "dominant modification" of normal (Mm) merle, in that the Harlequin gene acts on the merle gene to produce the Harlequin coat pattern, so the Harlequin Great Dane, in Neil O'Sullivan's eloquent phrase is a "dual heterozygote (HhMm)."

The merle mutation is a "dominant" mutation of a pigment gene known as SILV that produces a protein called PMEL17. Merle is a semi-dominant, meaning this one gene with only two alleles produces three distinct phenotypes: non-merle, normal merle (the heterozygote) and white merle (the homozygote which is commonly defective & referred to in Danes as a merlikin). The merle gene produces a characteristic increase in white areas & in areas of reduced pigment, with patches of mid-tone and full pigment in the heterozygote typically, with the homozygote usually being mostly white. No merle ever inherits a copy of the harl gene.

The harl mutation is also a "dominant" mutation where the "wild type" allele does not reduce pigmentation. The harl mutation acts as a modifier on merle dogs, further reducing the amount of pigment seen in the coat. Dogs without a merle gene can carry the harl gene sight unseen. Both Harlequin and Merle Great Dane have black pigment left behind because every normal Merle & normal Harlequin have one copy of the "wild type" gene for both merle and harl genes. A dog with two copies of the merle mutation AND one copy of the harl mutation appears mostly white with some black & some merle patches possible in a pattern referred to as "white." (Any embyo that receives two copies of the harl gene is apparently resorbed.)

An important take home message of this recent research which parallels breeder knowledge accumulated over many decades is that all Harlequin and Merle Great Danes are unique; like snowflakes no two are ever exactly alike. This is because of the unique nature of the merle gene: for all that all Harlequins & Merles inherit the same merle mutation, the affect will vary in every individual dog. The coat pattern therefore cannot be controlled as to the details of pigment distribution (i.e. specific patterning will necessarily vary).

How this effect is exactly achieved is currently being explored by Dr. Clark's laboratory. Her earlier work included the discovery of the merle gene, as well as the isolation of the harlequin gene to chromosome 9 (see PDF & other links below). The GDCA's Charitable Trust underwrote the advent of this research through "The Harlequin Gene Project" and the Board of Directors has recently voted to again devote funding to Dr. Clark's continuing exploration of the harlequin gene & its interaction with merle and other genes in the Great Dane. We thank Dr. Clark for her continuing interest in our breed.

The above is a layman's explanation of the genes producing the Harlequin and Merle phenotypes.

For a more detailed explanation, see the following links:

Standard Coat Color Genetics For Breeders: http://www.chromadane.com/standardcoat.htm

Coat Color Alleles in Dogs: http://homepage.usask.ca/~schmutz/dogcolors.html

Recommended Reading:

Genes Affecting Coat Color In Domestic Dogs: a Review: http://www.ncbi.nlm.nih.gov/pubmed/18052939

Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog: http://www.pnas.org/cgi/content/abstract/0506940103v1

Genome-wide linkage scan localizes the harlequin locus in the Great Dane to chromosome 9
http://www.ncbi.nlm.nih.gov/pubmed/18513894
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Sara
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01-10-2011, 10:10 PM
OK so according to that the Harle is just like the merle, in that it is a dominant characteristic. We call Harle x Merle Merlequins in our deaf dog yahoo group, we all knew that Harle was from Merle, and acted the same way, as you can get deaf and blind puppies from Harle to Merle matings, same as merle to merle. Interesting though that puppies die invitro if they have double harle genes... very interesting, that I did not know.

This guy was a deaf and almost blind dog that I rescued and transported to a rescue in Spokane, WA

the rescue called him a lightly marked harle... he was awesome!
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Jenn~n~Luke
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01-10-2011, 11:06 PM
He's sweet...Thank you for helping in his rescue. I have the utmost respect for those who rescue and foster, and those who take on special needs danes.
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Tassle
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02-10-2011, 08:42 AM
So - If I am reading that correctly - any Harlequin could in theory produce a Merle pup?

I had always thought that it was similar to the Merle gene - long ago (16 or so years) I was training with someone who worked Harlequin Merles in obedience, she was looking to get another pup, and was explaining to me that a)you cannot breed harl/harl and b) you cannot guarantee a Harl even if one parent is.

I will Ask his owner what colour his parents are when I next speak to her.
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