Using data from dogs that underwent direct-to-consumer genetic testing, researchers have teased out genetic variants associated with blue eyes among dogs, Slate reports.
Blue eyes are common among Siberian huskies and are also found, to a lesser extent, among border collies, corgis, and old English sheepdogs, Embark Veterinary's Aaron Sams and his colleagues write in a preprint appearing at BioRxiv. The researchers conducted a genome-wide association study that drew upon 6,000 dogs that underwent genetic testing using kits from Embark and whose owners provided phenotypic data. They uncovered two genetic variants linked to blue eyes: a known locus on chromosome 10 at PMEL17, which is also linked to merle or piebald coats, and a novel locus on chromosome 18.
The researchers found that the novel variant on chromosome 18 — a 98.6-kilobase duplication — was found among all blue-eyed Siberian huskies in their sample and note it is located upstream of ALX4, which is involved in mammalian eye development.
In addition to the potential for breeders to select for blue-eyed dogs, Slate says the study suggests that dogs could be studied as models of human diseases. "Having shared our environment for so long — and seen us through some key transitions in the process — might put dogs in a unique position to tell us about ourselves," it adds.