Wisdom Health Genetics Publishes Study on Mutation of Gene Responsible for Dog Coat Color

Wisdom Health Genetics, a world leader in pet genetics and maker of the WISDOM PANEL dog DNA test, announced today the publication in Canine Medicine and Genetics of the study “Comprehensive genetic testing combined with citizen science reveals a recently characterized ancient MC1R mutation associated with partial recessive red phenotypes in dog.”

In the study, researchers characterize the impact of an ancient gene variant on coat colors in modern dog breeds. Using data from Wisdom Panel products, researchers conducted genotype analysis to determine the distribution and frequency of the ancient R301C variant in the Melanocortin 1 Receptor gene (MC1R).

Remarkably, the research found the R301C variant to be the most common MC1R variant in some Spitz breeds (Alaskan Malamute, Alaskan Klee Kai, Northern Inuit Dog, Siberian Husky) and Hound breeds (Drever and English Foxhound).

“We sought to determine whether the ancient R301C variant is present in today’s dog population, and if so, what effect it has on a dog’s coat color phenotype,” said Heidi Anderson, Ph.D., Senior R&D Manager at Wisdom Health Genetics. “Our findings indicate that the R301C variant represents a novel reduced function allele of the MC1R gene that results in various reddish-yellow enriched phenotypes and explains the coat color patterning known as ‘grizzle’ in Chihuahua, ‘domino’ in Alaskan Malamute and other Spitz breeds and ‘pied’ in Beagle. We designated this newly characterized variant as ancient red (eA).”

The study leveraged citizen science—comparing the dogs’ coat color variant genotypes with owner-provided photos of the dogs’ coats. This allowed researchers to further understand the influence of R301C on MC1R, a variant in a gene associated with the melanistic mask, grizzle/domino and recessive red coat color phenotypes.

“Pet parents and breeders play a crucial role in genetic research by supporting studies of the genetic background of traits and their respective phenotypes,” said Rebecca Chodroff Foran, Ph.D., R&D Director at Wisdom Health Genetics. “Without their willingness to participate in citizen science, we would not have been able to make these discoveries.”

This study underscores the importance of not only genetic testing across a large number of dog breeds but also the role of citizen science in furthering scientific discoveries in companion animal genetics.

Pet owners interested in learning more about Wisdom Health Genetics research and citizen science efforts as they become available can do so here.

About the ancient

• Signaling at the Melanocortin 1 Receptor gene, known as MC1R, determines a dog’s coat color. The MC1R gene produces a key signaling molecule that helps determine both the expression of eumelanin (black/brown color) and pheomelanin (yellow/red color) and the location of the pigments throughout the body and individual hairs. Variation in the MC1R gene is associated with several coat color phenotypes, or appearances—namely the melanistic mask, grizzle/domino and recessive red color in dogs.
• In this study, researchers explored the Wisdom Health Genetics database—totaling more than 2 million samples—to identify dogs genotyped for the R301C variant. The researchers then leveraged citizen science to compare the genotypes to the dogs’ actual coat color phenotypes using photos provided by the dogs’ owners.
• First identified in 10,000-year-old prehistoric dog DNA samples, the R301C variant is one of the earliest mutations found in dogs. It likely represents one of the first coat color variations related to dog domestication. In today’s dogs, this variant causes coat color patterns referred to as domino in Alaskan Malamute and other Spitz breeds, pied in Beagle and grizzle in Chihuahua.

● For the study, owners collected DNA samples from their dogs via cheek swab. The 11,750 dogs studied represented 304 breeds and varieties and included 391 mixed-breed dogs. Researchers found the R301C variant present in 35 of the breeds or breed varieties at a frequency of 1.5 percent in this study sample