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mixeduppup

Colour Question?

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This is the best coat colour genetics webpage - written by one of the leading scientists studying canine coat colour (among other things). There are many genes that are yet to be identified.

http://homepage.usask.ca/~schmutz/dogcolors.html

Basically there are two types of colour pigment (phaeomelanin and eumelanin) and there are several genes which alter the colour of either of the pigments or the way the pigment is laid down in the coat (i.e. coat colour patterns like black with tan points or sable).

Most of the "dilution" genes are yet to be genetically identified.

Main genes are A locus (Agouti), E locus (MC1R), B locus (Tryp1) and K locus (CBD103). The interactions between these genes affects coat colour patterns of a dog.

Some coat colours appear to be the same genetically but are phenotypically different in different breeds - likely a yet to be discovered modifier gene.

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Tan points can be shown but it's not a popular choice for some reason :(

That's a shame, I think tan points are so attractive. I've never seen a red and tan show line kelpie only the red or chocolate as they're called and pure black. Seems a shame since the orginal kelpies had tan points.

Edited by mixeduppup

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asal   

asal, Dancnbcs has a better grip on this than me and will no doubt explain it better but here is my attempt :)

Chocolate is recessive to black. So to be choc they need 2 chocolate genese. Dilute is a separate gene that affects the way either colour is expressed. So a black dog with the dilute genes will appear as blue. A chocolate dog withe the dilute will be lilac which is genetically the same as a fawn kelpie and a Weimaraner.

I have never heard of 2 different "colour" dilutes rather a single gene that affects the way the dog's actual coat colour is expressed. More than happy to stand corrected - colour genetics is fascinating and confusing and the fact different breeds have different names for the same thing does not make it easier :)

thanks for the explaination.

to me chocolate acts a a dilute hence me using that word.

same reason I visualise blue as a dilute.

in so much that neither can express unless its in double dose

what neither can do is express as either chocolate or blue on a non black based dog in any form other than the nose and eye rims.

yet on a black based dog the coat will be either blue or chocolate or as stated in conjunction together turn a black based to lilac or what ever word is applicable to the different breeds.

as well in the case of a non black based dog the nose and eye rims still show the same nose and eye rim colour seen in the black based dog, only the dd bb cannot influence the coat colour, except in the case of those which also carry the black ticking on the end hairs that is the Sable description.

in which case the black ticking is changed to either chocolate ticking, blue ticking or lilac ticking.

as well in those with the inheritance of the black mask on and otherwhise red based dog the mask will show the presence being instead chocolate, blue or lilac

the way words are used to describe these two genes can be incredibly confusing,, there really needs to be some form of conformity doesnt there.

:thumbsup:

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Kavik   

It doesn't seem overly complicated to me - from what I understand from the Kelpie colour link I posted:

A dog is either genetically black or brown (same locus - B)

With or without tan points (A locus)

Then there is dilute of these (D locus. dilute black = blue, dilute brown = fawn)

And then red (cream) which is a masking gene (E locus) - the dog will be either genetically black (black nose) or brown (brown nose) but this is masked and the dog will appear cream

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Weasels   

Basically there are two types of colour pigment (phaeomelanin and eumelanin) and there are several genes which alter the colour of either of the pigments or the way the pigment is laid down in the coat (i.e. coat colour patterns like black with tan points or sable).

Most of the "dilution" genes are yet to be genetically identified.

Main genes are A locus (Agouti), E locus (MC1R), B locus (Tryp1) and K locus (CBD103). The interactions between these genes affects coat colour patterns of a dog.

Some coat colours appear to be the same genetically but are phenotypically different in different breeds - likely a yet to be discovered modifier gene.

thank dog you're about ML, this stuff makes my brain melt :laugh: It's strangely comforting to know the genes are still being discovered, since there's so much variation :)

That's a shame, I think tan points are so attractive. I've never seen a red and tan show line kelpie only the red or chocolate as they're called and pure black. Seems a shame since the orginal kelpies had tan points.

It is a shame, I'm quite partial to tan points too :) There is a red & tan show pup in WA, owned my Mirawee, and she is just gorgeous :love:

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Ignoring white markings, dogs can only have two types of colour pigment - Eumelanin (black) and Phaeomelanin (yellow).

With genetics lower case letters are recessive to upper case ones. A dog with one of each appears as the upper case one but "carries" the lower case one. So "BB" is black, "Bb" is black carrying brown, "bb" is brown, etc.

All dogs have genes at in the series A (sable/tan point), B(black/brown), D (dilute), E(yellow), K(pattern)and M(merle. Plus some extras for masks, markings, etc. the interaction of all these genes determines what colour/pattern the dog is.

Eumelanin - determines the base colour of the dog, so the nose, lips, eye rims and coat, unless a coat pattern is expressed in the coat. The basic eumelanin colour is black "BB", a mutation of black is brown "bb". The dilution gene "dd" turns black to blue and brown to fawn/lilac. If a dog is also "KK" it can only have a solid coat colour of Eumelanin with no yellow hair. The dominant merle gene "Mm" only affects the Eumelanin and only needs one copy to be expressed. So every merle must have one merle parent and two merles should never be bred together.

If however the dog is "kk", it can have any of the coat patterns produced by Phaeomelanin (yellow hair), such as yellow coat "ee", tan point or sable. These patterns have lots of different names in different breeds but they are basically all the same and can have any of the 4 base colours for nose, etc. The recessive yellow "ee" overrides all coat colours and patterns so a dog can also be genetically, sable, tan point or merle, but will just look yellow.

The dilution gene "dd" does not affect Phaeomelanin. The intensity of the yellow hair, from white through to chestnut is determined by modifying proteins and in the case of pure white breeds like Samoyed and JS, possibly by a chinchilla modifying gene that is yet to be identified.

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asal   

thankyou for taking the time to explain so easily to understand.

my learning was with horses and very diffent wording

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This is great, it's not that hard to understand once someone breaks it down for you, still studying up though, it's very interesting

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This is great, it's not that hard to understand once someone breaks it down for you, still studying up though, it's very interesting

The basics are pretty easy to understand once you get your head around the genes all working together. Keep reading up on it and it will make more sense.

Also keep in mind that mother nature doesn't always play by her own rules and odd mutations occur that cannot be explained by scientific knowledge to date.

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Well see the dog in my avatar. When I first got him he was a light red colour with tan points, as he matured he got darker and darker. Now he has black hair all over his back and he looks almost mahogany in colour. His mum was black and his dad was black with slight tan markings and his litter mates were all black except for one pure red one. Do you think he'll get more and more black as he gets older? (I'd post photos of his coat, but he's busy mustering up in Queensland)

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