Why huskies have blue eyes

DNA tests of more than 6,000 dogs revealed that a duplication on canine chromosome 18 is strongly associated with blue eyes among Siberian Huskies, according to a study published on October 4, 2018 in the open access journal PLOS Genetics by Adam Boyko and Aaron Sams of Embark Veterinary, Inc., and their colleagues. Embark is a dog DNA start-up based in Boston, Massachusetts, and Ithaca, NY, and research partner of the College of Veterinary Medicine of the University. Cornell. According to the authors, this is the first genomics study conducted for consumers ever conducted in a non-human model and the largest association study involving the dog genome conducted nowadays.

Consumer genomics allows genetic discovery on an unprecedented scale by linking very large genomic databases to phenotypic information voluntarily submitted via web surveys. But the promise of genomic consumer data is not limited to human research. Genomic tools for dogs are readily available, but the genetic basis for many important traits remains to be discovered. Although some genetic variants are known for the color of blue eyes in some dogs, they do not explain the trait in other dogs, such as Siberian Huskies.

To fill this gap in knowledge, Boyko, Sams and his colleagues used a diverse panel of 6,070 genetically tested dogs whose owners provided phenotypic data through web surveys and photo downloads. They found that a duplication of 98.6 kilobases on chromosome 18 near the ALX4 gene, which plays an important role in the development of mammalian eyes, was strongly associated with a change in the color of blue eyes, mainly in Siberian Huskies, but also in non-marine Australian Shepherds. A copy of the variant was sufficient to cause blue eyes or heterochromia (blue and brown eyes), although some variant dogs do not have blue eyes; other genetic or environmental factors are therefore always involved. Future studies on the functional mechanism underlying this association could lead to the discovery of a new pathway by which blue eyes develop in mammals. In a broader perspective, the findings highlight the power of discovery based on consumer data in non-human species, particularly dogs, where the owner is keenly interested in the personal genomic information of their pets, as well as that to a high degree of participation in web surveys. and an underlying genetic architecture ideal for mapping studies.

Aaron J. Sams adds, "By using the genetic data from our customers' pets, combined with the eye color reported by customers for these same animals, we have discovered a genetic duplication strongly associated with the color of blue eyes. study demonstrates the power of Embark's approach to improving canine health: in a single year, we have collected enough data to conduct the largest dog study of this type Embark is currently pursuing similar research projects morphological and health traits, continue to use our platform to advance dog genetics and health in a very practical way. "

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More information:
Deane-Coe PE, Chu ET, Slavney A, Boyko AR, Sams AJ (2018) Direct DNA testing of 6,000 dogs revealed a 98.6 kb duplication associated with blue eyes heterochromia in Siberian Huskies. PLoS Genet 14 (10): e1007648. doi.org/10.1371/journal.pgen.1007648