A dog DNA startup company called Embark, based out of Boston, Massachusetts, and Ithaca, New York, appears to have finally solved the mystery as to why huskies sport their beautiful blue eyes. The study is the first consumer genomics study ever conducted in a non-human model, as well as the largest canine genome-wide association study to date, reports Phys.org.
The key, it turns out, lies in the dogs' 18th chromosome. A duplication on chromosome 18, near the ALX4 gene, was found to be strongly associated with blue eye color. The ALX4 gene plays an important role in mammalian eye development, so this association is not entirely out of left field. And interestingly, the study also found this same genetic quirk in non-merle Australian shepherds, which also tend to have blue eyes.
This flies in the face of how eye color is usually thought to be determined in dogs. For instance, two genetic variants are known to underlie blue eye color in many dogs, but scientists have long known that these variants do not explain the blue eyes of huskies, thus the mystery.
In fact, even though we're seemingly in a genomic scientific age, the genetic underpinnings of many traits in non-human animals are still largely unknown, even for humans' best friends. Embark aims to change that.
For the study, which was performed in partnership with Cornell University College of Veterinary Medicine, researchers used a diverse panel of 6,070 genetically tested dogs, with owners who contributed phenotype data — physical traits of the dogs — via web-based surveys and photo uploads. A comprehensive, consumer-driven survey of this size is largely unprecedented.
"Using genetic data from the pets of our customers, combined with eye colors reported by customers for those same animals, we have discovered a genetic duplication that is strongly associated with blue eye color. This study demonstrates the power of the approach that Embark is taking towards improving canine health," explained Aaron J. Sams of Embark. "In a single year, we collected enough data to conduct the largest canine study of its kind. Embark is currently pursuing similar research projects in a range of morphological and health-related traits and we hope to continue to use our platform to move canine genetics and health forward in a very real way."
It's all in the name of improved health care options for our canine companions, as well as helping curious human owners better understand the origins of their pets. Answering why huskies have blue eyes is just the first such mystery they hope to solve.