The aboriginal people who bred Siberian huskies as sled dogs might not recognize the array of coat colors and patterns this breed comes in now. Since albinism is not known to affect Siberian huskies and white isn't considered a naturally occurring color, if the Chukchi saw an all-white dog, it would have been the product of a rare genetic fluke. Today, DNA analysis has taken some of the guesswork out of breeding dogs for specific coat colors, making the task of producing two entirely different types of white-coated Siberians much easier.
History of the Siberian Husky
The history of the people inhabiting the Chukchi Peninsula on the Bering Strait extends back before the last great ice age. In fact, an analysis of mitochondrial DNA sequencing published in 1998 in "The American Journal of Human Genetics" concluded that the Chukchi have been there for at least 34,000 years. These aboriginal Siberians considered the sled dogs crucial to their survival in the frozen Arctic to be living embodiments of their ancestors' spirits, treating them with love and respect. Throughout good times and bad, the Chukchi shared their food and tents with their dogs. When the adults took dogs with them on hunting trips, they left other dogs at home to baby-sit children. Over the centuries, the qualities most valued by the Chukchi in their dogs -- strength, endurance and an affectionate nature -- became characteristics of the breed we know today as the Siberian husky. In 1930, the American Kennel Club formally recognized the Siberian husky, praising the Chukchi for maintaining the purity of their traditional dogs, one of the world's oldest breeds.
The Genetics of Coat Color
Siberian husky breeders treat the genes responsible for coat color like a painter's palette. They've learned that each color-related gene holds the potential to be intensified, diluted with white or mixed with other genes to produce different shades and patterns. In Siberian huskies, the most common coat pattern is known as "Irish." The backs of dogs with Irish-pattern coats can be any solid color but the underbelly, chest, legs and paws must be white and the face a "mask" consisting of both colors. Siberian huskies are double-coated but the genes governing the color of their undercoats are different from those determining the color of their topcoats. This makes the task of breeding for monochrome coats, in which all hairs in both layers are the same color, much trickier -- and breeding for white coats the trickiest of all.
Breeding Pure White Huskies
To breed Siberian huskies for coats consisting of only one color, the influence of two recessive genes responsible for producing white hairs must be blocked. To produce all-white coats, the opposite process must take place. Pure or extended white coats only occur when puppies inherit two copies, one from each parent, of the gene responsible for producing white hairs. Within this genotype, all pigment-producing genes are present, but white trumps their influence. According to the International Siberian Husky Club, when one colored dog carrying the white gene is mated with an all-white dog, about half the puppies in the litter should be pure white. Coming up with more complex versions of extended white coats, such as those with silver-tipped hairs or silver undercoats, requires even greater attention to parentage.
Isabella White: A Different Genotype
Not all whites are the same shade of pale and the difference between a pure and Isabella white coat is like the difference between a natural and bleached blond, quips the ISHC. A puppy whose coat will turn Isabella white can be born with a dark-colored or patterned coat but over time, the pigments oxidize, fading to buff, cream or pale yellow. After this process is complete, the original pattern is often still visible in contrasting shades of facial and coat markings. As with extended white coats, tones of the undercoats and topcoats of Isabella white dogs can vary. Choosing parents most likely to produce puppies with white coats used be a more hit-and-miss process than it is now, when DNA analysis can be employed to reveal exact coat color genotypes of prospective parents.
References
- American Kennel Club: Siberian Husky: History
- International Siberian Husky Club: Color Genetics
- International Siberian Husky Club: White Siberian Huskies
- AKC Syndicate
- VetGen: Canine Coat Color:
- Hetta Huskies: History of Sled Dogs
- The American Journal of Human Genetics: mtDNA Diversity in Chukchi and Siberian Eskimos
- Science Daily: Native American Populations Descend from Three Key Migrations, Scientists Say
- "The International Siberian Husky Club Inc. presents The Siberian Husky"; Ginny Emrich Rice, 1977
Resources