I am not a geneticist. Instead I’m just a Malamute owner with a particular interest in this topic. I have bred small animals (rats, mice, and Syrian hamsters) for almost 20 years, and the practical experience gained through that medium has left me fascinated with coat color genetics. The information I am going to present here is not an in-depth discussion on the mechanics of color genetics. Instead it is intended as a basic overview, with the goal of de-mystifying the subject for those with little genetics background.
Coat color genetics is not some magical system for predicting the color of animals, nor is it an elaborate mathematical equation which can only be solved by a brilliant scientist. Instead it is a straightforward way of identifying why a dog is a particular color and determining how that color will be passed along to its offspring.
Before going into the details of the different coat color loci, I want to make brief mention of the notations you will see me use throughout this article. Each locus is represented by a letter (or sometimes a
couple letters). The dominant allele at a particular locus is always represented with a capital letter. A recessive allele is represented with a lower case letter. For each locus I will give the letters which
symbolize both the dominant and recessive form. Every dog has two alleles at each color locus, one inherited from its mother, and one from its father. You will sometimes see me list two of the same letters together. When doing so I’m talking about the effect of the gene on a particular dog when it inherits the various combinations of alleles possible. These combinations include inheriting:
The dominant allele from each parent (homozygous dominant - ie. “BB”)
The recessive allele from each parent (homozygous recessive - ie. “bb”)
Or one dominant allele from one parent, and one recessive allele from the other parent
(heterozygous - ie. “Bb”).
Beyond that, I am not going to go into the mechanics of how genetics work. It has already been done numerous times by people who are much more knowledgeable than I will ever be. Instead, I will be discussing the specific loci involved in determining the colors, markings, and coat types we most commonly recognize in Alaskan Malamutes. For those unfamiliar with the basics of dominant and recessive modes of inheritance or who need a refresher, there are many good articles on the web. One I can recommend is at: http://bowlingsite.mcf.com/Genetics/BasGen.html
Pigment A dog’s color is caused by the pigment in its hair. There are only two basic pigments, eumelanin which causes black/brown color, and phaeomelanin which causes yellow/red color. The distribution and
density of these two pigments throughout a dog’s coat is what causes it to be a particular color.
The distribution and density of pigment in a dog’s coat is dictated by various genes. The position which these genes occupy on the chromosome is called its locus. Each locus is responsible for a distinctive
effect on the pigment in the coat, and all the loci taken together “spell out” what the dog will look like.
There are six different loci which each play a part in determining what color a Malamute ends up being. Each of these plays a separate and distinct role, and each operates completely independent of the
others. All of these factors, considered together, “spell out" what color the Malamute will be.
Pigment Distribution – Banding
The first two loci we are going to look at control how the two pigments (eumelanin and phaeomelanin) are distributed on each hair. If you pluck a few guard hairs from a malamute’s coat at the shoulders (or just part the coat and take a close look) you will see that each guard hair contains a pattern of bands. The exceptions, of course, are black and whites and solid whites where the guard hairs are all one color. On a typical sable malamute you will see a black tip, a yellow/red band, a second black or gray band, and then light yellow/red down by the base of the hair. What you are seeing is a pattern of first eumelanin at the tip of the hair, then a band of phaeomelanin, then another of eumelanin, and a final band of phaeomelanin down near the skin. As you move down the sides of the body it becomes much more difficult to clearly detect all the various bands in the hair.
Banding in the coat of a Sable Malamute. Note the 4 different bands of color visable.
Agouti Locus
There are many agouti alleles which have been documented in mice and other species of animals. This locus is still being studied and documented in dogs, and at this time a number of alleles are known to
exist. It appears that only two agouti alleles are found in Malamutes. All Malamutes are either Agouti pattern or Tan Point pattern.
A - Agouti Pattern Also known as wolf pattern or wild pattern, this is very similar to the pattern seen in wolves. Other sources may use the letters aw or ag to represent Agouti. This allele produces a pattern of a black tip, a yellow band, a black band, and then a light yellow band at the base. The Face does not usually have distinctive tan point markings, and instead of a clear “bar” on the top of the muzzle the color "bleeds" down around the face.
at - Tan Point Pattern Also known as Black and Tan (we call them Black and White), these dogs are black on top and tan on the bottom with distinctive facial markings. Their facial markings are heavier than is seen in Gray or Seal dogs. This is particularly noticeable when they are pups. In Malamutes, other factors frequently alter the phaeomelanin that would
otherwise create the "tan" legs and points, leaving these dogs black and white. In its homozygous form, this allele produces solid colored black guard hair on the dorsal or top surface of the body. Essentially the black band at the tip of the hair extends to cover the entire hair. The undercoat is always solid black or gray.
The agouti locus is interesting because its alleles are incomplete dominants. That means that a dog who is heterozygous (has one “A” gene and one “at” gene) often looks different from a dog who has two “A” genes (AA) or two “at” genes (atat). In many cases the heterozygous “Aat” dog’s color will appear to be something in between, with markings more like a Tan Point, but colored like an Agouti. This feature becomes less distinct when impacted by Domino, however it can
often still be seen as an increase in facial markings.
Domino Locus Domino is a locus which has been theorized in dogs, but not studied at this date. What is known about this locus comes from a small handful of breeds including Malamutes, Siberian Huskies, Finnish Lapphunds and Lapponian Herders. Domino is recessive to non-domino, and is responsible for the appearance of most Malamutes. Domino acts on the agouti locus, reducing facial markings and eliminating the sootiness seen in Agouti dogs. This can particularly be seen in pups, where large white "eyebrows" and a well defined mask on the face right from
birth are a classic sign of Domino. Domino also extends the size of the phaeomelanin bands in the coat. In Agouti this eliminates most banding except along the topline, leaving just the dark eumelanin tip on an otherwise light hair, and giving an overall grizzled appearance. In Tan Point dogs, Domino produces a phaeomelanin band at the base of the hair.
Dom - Non-Domino
These dogs will appear to be Agouti or Tan Point as described above.
Compare the "AA" Domino dog on the left and the "atat" Domino dog on the right with the non-Domino dogs pictured in the Agouti section. Note the crisp facial markings.
Pigment Altering Loci
The rest of the loci in Malamutes deal with the density and appearance of each kind of pigment. They simply change the appearance of the pigment bands that have been determined by the Agouti and Domino loci. These pigment factors are NOT dominant or recessive to each other, or to the Agouti or Domino alleles. Instead each one operates independently and each one is present in every single dog.
Chinchilla-like Locus Traditionally the "C" or Chinchilla locus is responsible for turning phaeomelanin very pale in other species. Thus far studies show that “C” is not the locus which has this effect in dogs. No one has determined what locus it is, however. Thus I'm using "Chinchilla-like" locus instead of just Chinchilla Locus.
The recessive allele at this locus lightens/removes phaeomelanin pigment (the yellow/red band) wherever it appears in the dog’s coat. It does not affect the eumelanin (black/brown) pigment at all. It also has no effect on eye color or skin pigment so nose color remains black. This locus is responsible for changing Sable into Gray, and Dark Sable (or Seal Sable) into Seal.
Cl - Sable
Full color. Both black/brown and yellow/red bands are expressed as are the tan under-parts in some dogs. We usually call this color Sable, however the Agoutis shown above as well as any Tan Point that shows
its tan pigment are also "Cl" or Sable. It is worth noting that genetically the term "Sable" is not correct for this color, and in other breeds Sable refers to another color all together.
The intensity and depth of color in the phaeomelanin can vary greatly in Malamutes from a deep redish brown to a pale off white. Often the very palest off white Sables are mistaken for Gray and Seal. Sable
pigment also changes over time, often becoming darker or lighter as the dog ages. Some Sable dogs show the phaeomelanin pigment in their faces ranging from peach colored to a deep burnt orange. In other dogs
this pigment is not seen.
The only difference between these dogs and the sables shown above is the Chinchilla-like locus removing phaeomelanin from the coat
Brown Locus (Red) The recessive allele at this locus changes black (eumelanin) pigment to chocolate brown wherever it appears on the dog. It slightly lightens red/yellow (phaeomelanin) pigment.
B - Black
The black band in the coat as well as nose and skin pigment is unaffected and remains black.
Dilute Locus (Blue) Also called the "blue" locus. The recessive allele at this locus changes black (eumelanin) pigment to dark slate gray wherever it appears on the dog. It also takes the red out of the red/yellow (phaeomelanin) pigment, lightening it somewhat and making it appear dull.
D - Non-Dilute
The black band in the coat as well as nose and skin pigment is unaffected and remains black.
d - Dilute (we call them Blue)
The black band is changed to dark slate gray. Pigment on nose, eye rims, lips, and pads is also changed to dark slate gray. Eye color is yellowish or hazel, sometimes with a gray or bluish cast.
White Spotting
Spotting Locus In addition to banding on the hair and color of pigment, white spotting is also present in Malamutes. There is often a lot of misunderstanding about what white spotting does and does not do. White spotting does NOT give us the white under-parts that are a trademark of Malamute color. That is instead caused by the Agouti and Domino loci, with some help from the Chinchilla-like locus.
White spotting gives us white areas in addition to the typically seen lighter under-parts. These can be difficult to find because they usually are in the same areas where Malamutes are already white (so we
don’t see them) or are in areas joining those already white (so folks don’t realize they are being caused by something different).
S - Solid Some Malamutes are homozygous “SS”, or solid colored. While they are referred to as "solid colored" these dogs actually can have very minor white spotting limited to their toes, chest, and tail tip. It is not
unusual for these dogs to have colored hairs running down the backs of their hocks, color bands that are unbroken or almost unbroken on their chest, and no white tail tip.
The appearance and depth of color in the yellow/red phaeomelanin band in sable dogs is controled by modifiers and can vary greatly. These dogs are all genetically Sable.
Heterozygous Agouti.
Again note the distinct Agouti eyerings.
Tan Point AKA Black & White
While the "tan" markings on malamutes are often pale or white, you can see the facial markings are identical to those of other tan point breeds like the Jindo on the left
Light rings around the eyes are a distinguising feature of Agouti
Regardless of their adult appearance, Agouti pups always have a very characteristic sooty color.
Two Domino pups on the left with their three Agouti (non-Domino) littermates
cl - Non-Sable (or Chinchilla-like dilute)
The black/brown band is unaffected. The yellow/red band is reduced to white or off white. The Chinchilla-like locus is responsible for removing the red or brown color from sables. We call the resulting
colors Gray and Seal.
An interesting side note is that this gene is notorious for “failing” along the line where the top color meets the points – leaving sable “trimmings” where you can still see the yellow/red band in the dog’s coat.
Extension Locus (White) The recessive allele at this locus overpowers the banding that would otherwise be dictated by the Agouti locus and instead programs each hair to have only phaeomelanin (yellow/red) pigment from tip to base.
As we have already discussed, Phaeomelanin is changed by the Chinchilla-like locus (cl), reducing this color to white or off white.
E - Full Color
The black/brown and yellow/red bands in the coat are unaffected.
e - Recessive Yellow (but in Malamutes this creates white)
Banding is eliminated so that the entire hair only contains yellow/red (phaeomelanin) pigment. When combined with Chinchilla-like (cl), all but the very darkest of this color is eliminated – leaving a White dog
sometimes with pale yellow or red “points” usually seen at ears and dorsal stripe. Pigment on the dog’s nose often fades to a pinkish color as the dog ages. Eye color and eye rims are not affected.
Combining Colors
While it is important to understand each locus and its effect on the pigment present in whichever coat pattern a particular dog happens to be, it is also important to realize that each locus does not exist in
a vacuum. Every dog has every locus, and the alleles at each locus will have their effect regardless of what's happening on the other loci. For instance, it's possible for a dog to be both a Red "bb" and
a Blue "dd". This would be called a dilute red or more correctly "Lilac". Dilute will still turn black pigment gray, and brown will turn that gray pigment into "red". But the red will appear duller and less vibrant than in a non-dilute red.
Red Sables. Phaeomelanin is visable in the faces of the pups on the left and in the undercoat of the dog on the right.
Lilac (Red + Blue) on the left. The color of this dog's pigment, particularly on the nose, is grayer and duller. The Red Sable on the right has pigment which is much more brown in appearance.
Putting it all together
Putting it all together, every Malamute is a combination of all these factors. As I said at the beginning of this article, all these factors taken together “spell out” the color we see on a particular dog.
Let’s take a couple examples:
Fido’s color genetic makeup looks like this – Aat Bb DD domdom EE clcl
Aat – hairs are banded with a black tip, red/yellow band, black band, and light red/yellow base
Bb – the black band is not turned brown
DD – the black band is not turned gray
domdom - crisp clean markings
EE – the black band remains
clcl - the red/yellow band is reduced to white or off white
And so Fido is a gray who carries Red and Tan Point
Rex’s color genetic makeup looks like this – AA BB Dd domdom EE Clcl
AA – hairs are banded with a black tip, red/yellow band, black band, and light red/yellow base
BB – the black band is not turned brown
Dd – the black band is not turned gray
domdom - crisp clean markings
EE – the black band remains
Clcl - the red/yellow band is not reduced to white or off white
And Rex is a sable who carries blue and non-sable
Midnight’s color genetic makeup looks like this – atat BB DD domdom Ee clcl
atat – Black tip extends the entire length of the hair
BB – the black band is not turned brown
DD – the black band is not turned gray
domdom - phaeomelanin band at the base of the hair
Ee – the black band remains
clcl - the red/yellow band is reduced to white or off white
And Midnight is a seal who carries White.
Flame’s color genetic makeup looks like this – atat bb DD domdom EE clcl
atd atd – Black tip extends most of the length of the hair with a red/yellow band at the base
bb – the black band is turned brown
DD – the black band is not turned gray
domdom - phaeomelanin band at the base of the hair
EE – the black band remains
clcl - the red/yellow band is reduced to white or off white
And so Flame is a dark red
As long as that explanation is, it's a very simplified version. There are also a number of other issues that could be discussed. Like modifiers that determine just how much of the hair tip is colored or the range of shades of color. Also not discussed are linkages like the one that appears to exist between Tan Point and Brown. I would encourage anyone interested to look further into this fascinating topic.
Sources:
A special thank you to Liisa Sarakontu. Without her willingness to share her knowledge, as well as her valuable comments and suggestions, this article would not have been possible.
My deepest gratitude to the following individuals who generously allowed me to reproduce photographs of their dogs for this article: Tina Robbins, Suz Richardson, Vicki Daitch, Michelle Frank, Cindy Neely, Bilinda Marshall, Lisa Kellar, Kathleen Corkum, Maurine Marcus, Bob Sturdivant, Sue Fuller, Phyllis Hamilton, Leesa Rhyde Thomas, Shilon Bedford, Judy Paule, Charlene LaBelle, and Dorothy Hood.
Si - Irish Spotting
Malamutes who have larger amounts of white spotting are often Irish Spotted “sisi”. Irish Spotting confines white spotting to the legs, end of the tail, chest, underbody, face, and neck. The white spotting does not cross the dogs back between their neck and tail. In Malamutes we have come up with a variety of names for the different places and ways Irish Spotting can express itself. Blazes, stars, split bars, eagle markings on the chest, white collars, nape or wither spots, and white tail tips as well as the variety of “mismarkings” that are occasionally seen are all usually caused by Irish Spotting.
Like the Agouti locus, incomplete dominance is often seen in white spotting. Dogs who are heterozygous “Ssi” frequently have more white than “SS” dogs, but less than “sisi” dogs.
Sp - Piebald
While not common in Malamutes, there is the possibility that Piebald might exist and occasionally appear in the breed. If it does, it would cause white patches along the sides of the dog, running upward from
belly towards the back. This would produce the broken color or uneven splashing that is listed as undesirable in the standard. This characteristic has been heavily selected against in the breed.
Not a Malamute, however this Inuit Sled Dog is a classic Piebald
Tan Point pups lack the clear cut facial markings seen in Seal pups.
Red can be found in any of the patterns seen in malamutes.
Agouti Red on the Left. Seal red on the right
As adults these dogs can resemble seals or grays due to other factors affecting their coat color, and it is not really unusual for some to develop more standard facial markings. As puppies their dark and sooty facial markings are a clear giveaway that they are agouti. Adult Agoutis often appear to have a light ring around their eyes when looked at head on, and this can be a tip that an otherwise gray or seal (or sable) appearing dog is actually an agouti.
Though clearly an Agouti as a pup, this dog's adult appearance could easily be mistaken for gray.
dom - Domino
Dogs that are homozygous for recessive Domino will have crisp clean facial markings from birth and an increase in the phaeomelanin band at the base of their coat. The vast majority of Malamutes are Domino. Domino turns Agouti into Sable or Gray and turns Tan Point into Seal.
b - Brown (we call them Red)
The black band in these dogs is changed to chocolate brown. Pigment on nose, eye rims, lips, and pads is also changed to a chocolate brown. Eye color is usually lightened. We call these Reds. Agouti or Domino Agouti reds are usually just called "red". Tan Point or Seal reds are frequently referred to as Mahogany Red or Dark Red.
Both Red and Blue can also express themselves in White dogs. While the coat color remains the same (white), you can see the effect of these genes clearly in the pigment of the nose and eye rims. Sable also occurs in both Red and Blue
These Malamutes are all solid colored. They have unbroken color on their chests, color extending down their legs, and little or no white on the tip of their tail.
White collars, blazes, nape spots, split bars, eagle markings on the chest, and white legs are all caused by Irish Spotting
A Domino pup (middle) among his non-domino Agouti littermates at two days old
The dogs in the front are blue. Compared to the dark gray (left) and Seal (right) in the rear, you can see the blue's coat color appears paler and slightly washed out.
The Brown locus changes black pigment to brown. The difference is clear in the two littermates. Note not just their coat color, but also their noses.
You can see the slightly washed out pigment on the noses and eye rims of these two Blues, as well as the yellowish or hazel eyes.
Pigment on the pads is also affected by the dilute locus (right).
