Why do Siberian Huskies have blue eyes? Points of study on chromosomes

SThe Iberian Huskies are very different from your golden retrievers and miniature schnauzers. Of course, they share a common ancestor – the wolf's separate dogs about 40,000 years ago – but the Huskies, with their ability to pull the sled and hunt prey, evoke some renegade. I do not know what. But perhaps what distinguishes these arctic men the most from their drooling peers is their pale blue eyes, which researchers are beginning to discard.

Scientists from Cornell University and the dog DNA company Embark Veterinary, Inc. recently came together to understand why the Siberian Huskies had blue eyes. In a study published Thursday in PLOS Genetics, they reveal that it is most likely a DNA molecule called canine chromosome 18. The team determined that there was a strong association between tandem duplication on canine chromosome 18, located near the ALX4 gene, and the development of blue eyes.

"We think it's a strong functional candidate because it's upstream of the Homeobox gene. ALX4, which other researchers have demonstrated the role in the development of eye and pigmentation in mammals, "says the chief scientist of Embar, Aaron Sams, Ph.D. reverse. "Our hypothesis, which has yet to be tested, is that this duplication can alter the expression of ALX4, which can lead to repression of genes involved in eye pigmentation. "

This study, the first consumer genomics study ever conducted on a non-human animal, involved the genetic data of 6,070 dogs owned by Embark clients. Some genetic variants are known to lead to blue eyes in species such as Australian Shepherds and Dalmations – sometimes with blue eyes or a blue eye and a brown eye – but these variants are related to dog coloration. For example, dogs with a merle pattern (marbled colored spots) or a piebald pattern (a predominantly white dog with colored spots) usually contain these genetic variants. However, these variants were not enough to explain why tricolor Australian shepherds and Siberian Huskies also have blue eyes.

"Actually [the tri-colored Australian Shepherds and Siberian Huskies] carry the duplication that we have identified, "says Sams. "So, it was a fun mystery to solve!"

This study provides a preliminary overview of what Embark can do with data on drinking dogs. Although owners are generally interested in the route taken by 23andMe to allow dogs to determine what raises parents of their dogs or to examine their pets for genetic health concerns, the aim of Embark is to "put an end to preventable diseases in dogs".

"The idea is that by providing a product directly to the consumer providing owners with useful and interesting information from DNA analyzes, we can collect high quality genotypic data in addition to phenotypic information and information." provided by dogs and their owners on an unprecedented scale. Said Sams. "With these data, we can conduct such studies to better understand the role of genetics and the environment in the development of diseases in dogs, thus improving the lives of both dogs and their owners."