Blue Eye Linkage Testing
Here’s a quick genetic reminder that the Dup locus blue eye testing on embark is a LINKAGE TEST.
What is a linkage test?
As per Embark, “A Linkage Test is a genetic analysis method used when the specific mutation can not be tested. When we are unable to test for a causative mutation (a single mutation known to cause a health condition or trait), we look at DNA sequences around a known causative mutation to see if it matches the DNA sequences of dogs already known to have said mutation and the associated genotype.”
What does this mean?
There is actually no single testable gene for blue eyes in that sense that has been identified. There are TWO genes that are more commonly found with blue eyed dogs, but it is not a proven, testable gene at the moment.
If you want blue eye production, PICK A DOG FROM A LINEAGE THAT PRODUCES ALL OR ALMOST ALL BLUE EYES. The test is redundant until they have more concrete evidence and actually identify the actual gene.
Reserarch on PLOS Genetics by P. E. Deane-Co at al finds that “The genetic underpinnings of many phenotypic traits in domestic dogs remain undiscovered. Although two genetic loci are known to underlie blue eye color in dogs, these do not explain all cases of blue eyes”.