Wolf Coat Color Genetics
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This webpage was mounted on October 4, 2014 and last updated on March 25, 2023 by Sheila Schmutz. email@example.com
A brief review of the genes controlling wolf (Canis lupus) coat colors and patterns. Some of this research was conducted in our own University of Saskatchewan lab, often as a comparison with the dog. Some is from the research of others.
I've only seen wolves in the wild once, and that was just a few winters ago in Saskatchewan. I didn't have a camera with me, and wasn't close enough to get a good photo anyway. I saw this wolf track in the Spatsizi wilderness of northern British Columbia and could at least photograph it! Some of the wolves we've studied come from this area. All of the wolves we've studied are from Canada.
DNA Studies To Date
Wolves have a wide geographic range and also considerable coat color variation, although not as much as the dog.
Tanned wolf pelts hanging on a wall, from a display at historic Fort Edmonton. Photo, Sheila Schmutz.
In a DNA study of the agouti signal protein (ASIP) in coyotes, wolves, and dogs, we found that there was no difference between the wolf and dog, except for a few mutations that cause specific coat color patterns in the dog (fawn, black-and-tan, and recessive black). Wolves exhibit the pattern known as wolf sable, with banded hairs on the back, and some solid black hairs interspersed. Some dogs also exhibit this pattern.
The wolf in the photo at the right shows the classic ASIP wild type pattern, with dark tipped hairs. Photo by Ray Collingwood, Collingwood Brothers, used with permission.
In 2021, a large collaborative study was done that included both wolves and dogs. The focus of this study was to understand the promoter regions of the ASIP gene, which had not been previously characterized. In dogs, the authors found 2 promoters: one that affected the amount of phaemolenin (red, yellow, cream) pigment that was produced on the ventral surface or undersides and another that affects the amount of phaeomelanin versus eumelanin (black, brown, gray) on the dorsal surface or back. Furthermore they found two forms of the ventral promoter (VP1 and VP2) and 5 forms of the hair cycle promoter (HCP 1-5).
However, in wolves they found both VP1 and VP2 but only HCP1 and HCP2. This is not surprising because HCP3, HCP4, HCP5 all cause no production of phaeomelanin on the back but instead a portion, to all of the back, are solid black - a coloration not seen in living wolves.
They included one pale wolf that was part of a previous study we'd done. #636 had the promoter genotype VP1-HCP1/VP2-HCP2. They further concluded that this VP1-HCP1 promoter combination arose in a canid ancestor over 2 million years ago, that is no longer alive. It has persisted in pale wolves today, and many dog breeds with the coloration often called fawn.
The more typical colored wolves, such as #732, have the promoter genotype VP2-HCP2/VP2-HCP2. (I thank Dr. Tosso Leeb, Switzerland, for providing the genotype for this wolf in an email).
The photograph is a mounted specimen on display at Elk Ridge Resort, on the edge of Prince Albert National Park, Saskatchewan. I've seen wolf tracks in the fresh snow there.
In 2013, Ollivier et al. of France published a very interesting study based on archaeological specimens of wolves and early dogs, and included some living dogs. They obtained the terminal portion of the MC1R gene from these samples. They describe the locations for two wolf samples as found "at Torgashinskaya cave ca. 15000 to ca. 12000 cal. BP in an Upper Palaeolithic context and at Ulug Depe ca. 5550– ca. 4000 cal. BP in a Bronze Age context". The former is in Siberia and the latter in Turkmenistan. Being archeological specimens, they can't know the coat color of either of these wolves. A third sequence was also contributed to GenBank. All three are identical.
DEFB103 (also called CBD103)
Wolves feeding on a frozen lake in the Spatsizi Wilderness of northern British Columbia. Photo by Ray Collingwood, used with permission.
The groups from Stanford and UCLA joined forces to uncover the genetic basis of black coat color in wolves (Anderson et al. 2009). They focussed on the wolves of Yellowstone park. The same 3 bp deletion that causes black in many domestic dog breeds, was found to cause black in the wolf pack there, and also from Canada. They suggest that this K
Ollivier et al. (2013) also studied the K locus in their archeological wolf samples. They detected one copy of the KB allele in a wolf sample from Ulag Deppe in Siberia. This allele was also found in 4 of their early dog samples.
In a study of Canadian wolves sampled at the former North American Fur Auction (NAFA) in Toronto in 2015, I also detected the the KB allele in a few "black" wolves. Because this study was done using pelts, I was able to photograph them closely. To my amazement, the "black" wolves were not actually completely black. They would and did look black from a distance (as in the group photo above), but not really, when one was close. Why the the KB allele causes a dog to be pitch black and yet not a wolf, is an intriguing question. It is likely explained by a gene interaction. I now believe that the wild allele at the ASIP gene, present in all pure wolves, is the reason for this interaction. That allele is NOT present in most dogs that are black.
The collaborative group from Sweden and Massachusetts has done a detailed "functional genomics" study to try to determine how 4 polymorphisms in the promoter region of the MITF gene might affect the amount and placement of the white markings in dogs. They studied the DNA for the promoter region of this gene from 60 wolves from various parts of the world.
Because they found all four polymorphisms in wolves, they suggest that none could be the sole cause of any type of white marking pattern in dogs. However, based on their Table S1, only a single Scandinavian wolf was homozygous for the Exon 1B polymorphism and none were homozygous for SNP 21. Eight of the wolves were homozygous for the SINE. The Length Polymorphism data were not listed for most wolves. Since piebald or random spotting is inherited as a recessive in most dog breeds, only homozygous wolves would be expected to have white spotting of this type.
Arctic Wolf (Canis lupus arctos)
This "white" wolf skin is part of a historic display at Fort Edmonton, in Edmonton, Alberta. The interpreter was kind enough to show the undercoat of this skin which is not white at all. The fur is so thick and creamy that one wouldn't expect to find banded agouti hairs beneath! Hence this is not strictly speaking, a "white" wolf.
Although the promoter genotype for the ASIP gene (discussed above) is not known for this wolf, it is possible that it is VP1-HCP1/VP1-HCP1, because it is so pale.
In 2019, Benoit Hédan and his colleagues discovered a mutation in the MFSD12 gene that causes cream when homozygous, and lightening, of reddish pigmented areas in dogs when heterozygous. This same mutation was found in some wolves. This seems to explain why the phaeomelanin pigment of wolves is more typically cream to white, instead of yellow or red.
The Canadian map above shows the locations of 15 wolves of various coat colors whose DNA was studied by Sheila Schmutz. Although the 4 pale or almost cream wolves were all trapped in the north, the 3 dark that are sometimes called black were not all trapped in the south.
Links to Related Sites
for further information contact:
Sheila M. Schmutz, Ph.D., Professor
Department of Animal and Poultry Science
College of Agriculture and Bioresources
University of Saskatchewan
Saskatoon, Canada S7N 5A8