DNA testing of more than 6,000 dogs has shown that a duplication on canine chromosome 18 is strongly associated with blue eyes in Siberian Huskies, according to a new study. According to the authors, this is the first consumer genomics study ever conducted in a non-human model and the largest canine genome-wide association study to date.
While two genetic variants are known to underlie blue eye color in some dogs, these do not explain the trait in some other dogs, such as Siberian Huskies.
To address this gap in knowledge, the researchers used a diverse panel of 6,070 genetically tested dogs with owners who updated phenotype data through web-based surveys and photo uploads. They found that a 98.6 kilobase duplication on chromosome 18 near the ALX4 gene, which plays an important role in mammalian eye development, was strongly associated with variation in blue eye color, mainly in Siberian Huskies but also in non -merle Australian Shepherds. One copy of the variant was enough to cause blue eyes or heterochromia (blue and brown eyes), although some dogs with the variant did not have blue eyes, so other genetic or environmental factors are involved. Future studies of the functional mechanism underlying this association may lead to the discovery of a new pathway through which blue eyes develop in mammals. From a broader perspective, the results underscore the power of consumer-driven discovery in non-human species, particularly dogs, where the owner is interested in their pets' personal genomic information, a high level of engagement in web-based surveys. and an underlying ideal for genetic architecture for mapping studies.
