Why huskies have blue eyes

Saliva-in-the-mail DNA tests have become extremely popular for a whole raft of reasons – from establishing paternity to researching genealogy.

As a result, the consumer genetics business has become a very profitable pursuit for lab owners, so it was probably only a matter of time before it spread beyond human boundaries and began to be offered for pets.

In a canny combination of marketing and genuine scientific research, the owners of US dog DNA testing start-up called Embark Veterinary have just had a paper accepted for publication in the journal PLOS Genetics.

By conducting tests on some 6000 dogs, company owners Adam Boyko and Aaron Sams have succeeded in answering a question that has long certain pooch breeders: why do Huskies have blue eyes?

To make their finding, Boyko and Sams conducted DNA tests on the dogs, and asked their owners to send in photographs. That way, they were able to correlate the genetic data with information regarding the breed, shape and size of each animal.

In doing so, they discovered that Siberian Huskies carry an unusual feature on chromosome 19. They found a “duplication directly upstream of the Homeobox gene ALX4, which plays an important role in mammalian eye development”.

This feature, which is almost completely restricted to pure-bred huskies, is strongly associated with blue eyes.

The result in observational, and thus cannot offer insight into the mechanics of how the duplication materially alters eye colour, but it is, nevertheless, of more than passing interest to dog breeders.

That, however, was not the primary finding of the research by Boyko and Sams.

That, the researchers write, is a bit more general, and a bit more pertinent to the nature of their start-up.

“These results underscore the power of consumer-data-driven discovery in non-human species, especially dogs, where there is intense owner interest in the personal genomic information of their pets,” they write.