Genes governing colour

Two genes, known as “B” (recessive form “b) and “E” (recessive form “e”), determine the basic colour.

ee

Dogs with two copies of the recessive “e” gene (one from either parent) will be light-coloured. Those with a liver nose carry for chocolate but not black (genotype bbee) and come in chalk, cream, or caramel. Those with a black nose carry for black, may or may not carry for chocolate (genotypes Bbee or BBee), and come in chalk, cream, gold or red.

photo courtesy of Aussie Labradoodles

photo courtesy of Davidson Doodles

Caramel & Gold
DragonRam Jasper “Oliver” & DragonRam Carnelian

Red - Aussie L’s Rudigan

Cream - DragonRam Peridot “Tory”

bb

Dogs with only one or no copies of “e” and two copies of the recessive “b” gene (one from either parent) will be chocolate, or its faded cousins Café, Lavender, or Parchment. They may or may not carry for shades of gold (genotypes bbEe or bbEE).

photo courtesy of
Manor Lake Labradoodles

photo by DragonRam Doodles

Cafe - Manor Lake Royal Savannah

Lavender - Sunsethills Ranger of Labradoodles by Design

Chocolate - DragonRam Sapphire

BxEx

Dogs with at least one copy of “E” and at least one of “B” will be black, or its faded cousins Blue or Silver. They may carry just for gold (genotype BBEe), just for chocolate (genotype BbEE), for both chocolate and gold (genotype BbEe) or for neither (genotype BBEE).

photo by DragonRam Doodles

photo courtesy of Alpen Ridge Labradoodles

Black - Urban Doodles Amore of DragonRam

Silver - Mis B-Havin Rachael

Blue - Alpenridge Blue Belle

The presence of the two copies of the recessive form of the D gene (dd) determines whether the coat colour will fade (from Chocolate to Café, Lavender or Parchment, or from Black to Blue or Silver).

Genes governing patterns

Dogs that do not belong to the Cream/Gold colour group (Ee or EE) can display patterns of sable, phantom, and brindle.

Two genes, known as K (dominant form K^B, recessive forms k^y and k^br) and A (dominant form A^y, recessive forms a^t, and a), determine whether a dog will show sable, phantom, or brindle patterning and what type of pattern will be expressed.

Sable and phantom patterns, and recessive black, are determined by the A^y locus.

aa

Dogs with two copies of the recessive “a” gene (one from each parent) will be recessive black.

a^ta^t or a^ta

Dogs with two copies of the recessive a^t gene (one from each parent), or one a^t and one “a”, will be phantom.

photo courtesy of
Canadian Doodle Puppies

photo courtesy of
DownUnder Labradoodles USA

photo courtesy of
Southern Charm Labradoodles

Canadian Doodles Guinness

DownUnder Hot Sake

Southern Charm’s Classic GT500 Shelby

A^y

Dogs with at least one copy of A^y will be sable. [Genotypes A^yA^y, A^ya^t, or A^ya]

photo courtesy of
Alpen Ridge Labradoodles

photo courtesy of
Alpen Ridge Labradoodles

photo courtesy of
Noble Vestal Labradoodles

Alpenridge Caidence’s Nathan

Alpenridge Dare To Be Rare

Noble Vestal Atta Girl

However, whether the phantom and sable patterning is visible on the dog depends on the “K” locus (dominant form “K^B”, recessive forms “k^y” and “k^br”), which also controls whether brindling (stripes) is present and visible.

k^yk^y

Dogs with two copies of the recessive “k^y” (one from each parent) will have the “A” locus visible, so if they have the form of the “A” locus that determines sable, phantom, or recessive black colouring, they will show that patterning, but without brindling.

k^brk^br or k^brk^y

Dogs with two copies of the recessive k^br (one from each parent) or one k^br” and one k^y, will have the A locus visible with the addition of brindling. If they have the form of the A locus that determines sable, phantom, or recessive black colouring, they will show that patterning, but with brindling overlaid.

k^Bx

Dogs with at least one copy of the K^B gene will be solid coloured. They will not be sable, phantom, or brindled, regardless of what they have at the “A” locus.  The presence of K^B blocks the A gene from being expressed.

It is not yet known what gene is responsible for the expression of the Parti or Abstract patterns. These patterns are independent of the E gene, as it is possible to have parti dogs in the Cream/Gold colour group.

Here are some interesting articles about colour genetics in dogs.

• VetGen
• University of Saskatchewan - contains links to other dog genetic and colour resources