Is the Ky allele in Wirehaired Pointing Griffons evidence of cross-breeding?
This has apparently been a burning question in the Griff community for several years and the cause of rifts among lovers of the breeds on various sides of the argument.
In short, every now and then somebody produces a Griff puppy with tan points resulting from Ky. This has been taken by some to be evidence of a deliberate or accidental cross-breeding in the past, punctuated by the assertion that the dogs carrying this allele are thus not "pure" WPGs and should not be allowed to breed.
Could the Ky allele have been present in that original gene pool? That would depend on how common it was and how it was distributed among dogs, recognized breed or otherwise.
Eduard Korthals developed the breed in the Netherlands in the late 1800s, with the aim of producing a gun dog that was versatile, hardy, and devoted to its master. To do this he crossed a variety of dogs, some of unknown lineage but carrying some of the traits he wished to produce in the breed. Among those of various types were probably spaniels, retrievers, pointers, and otterhounds. The breed was created as many others have been, as "blender breeds" that borrowed a bit of this from one breed and a bit of that from another to produce a new breed of dog well-suited to a particular purpose in the eyes of its creator.
So here are the crucial bits of information for this discussion of the Ky allele as evidence of genetic contamination.
1) The Ky allele is the ancestral form of the K allele. It is found in all wolves. It is thus likely to have been in the earliest dogs.
2) How common is the Ky allele in dogs? To answer this question, I contacted two highly-regarded canine geneticists with access to large databases of dog DNA data, including alleles for color: Dr Adam Boyko (Cornell University and Embark Vet) and Dr Jonas Donner (Genoscoper and MyDogDNA). They both confirmed first that the Ky allele is the ancestral K allele that is found in wolves. They also both said that the Ky allele is very widespread among breeds and dogs in general. Boyko said "I think it's in more breeds than not...even some black breeds like Schipperke and Belgian Sheepdog." Donner said that "Ky/Ky is the fixed genotype in the modern wolves we have tested, so yes it is the ancestral allele...The frequency of the ky allele in dogs overall is about 70%".
Not only is the presence of the Ky allele not evidence of a cross-breeding event, it would be surprising to NOT find it in a modern dog breed created by crossing various breeds as well as dogs of ambiguous lineage. Ky is recessive to other K alleles, so it can be present in a population for many generations without being expressed. Having a few tan point dogs pop up in a long line of dogs where this has never been seen is proof of nothing more than the roles of chance and allele frequency in the expression of recessive alleles.
There is no scientific or even rational basis for the claim that Griffs carrying the Ky allele are not "purebred" or "true" Korthals. The policy of some groups to purge all the "contaminated" dogs carrying the Ky allele from breeding populations is both wrong-headed and detrimental to the breed because it reduces the size of an already limited gene pool and unnecessarily removes quality dogs for a cosmetic trait that won't even be expressed if a dog is just a carrier. Those claiming that the "pure" or "true" Korthals does not carry this gene and that dogs that do are "just mutts" do a true disservice to the breed for the apparent purpose of elevating their own dogs to a higher status than others. This is not to better the breed, and it doesn't. It is nothing less than a shameless scam.
The data to disprove the fallacy of the claim that dogs carrying the Ky allele are descendants of cross-breeding are abundant and readily-available. There is no evidence that it is associated with any detrimental or undesirable trait in this breed (which has also been claimed) or any other. Remember: this is the K allele found in wolves. In fact, the K allele is not a "color allele". The K gene is otherwise known as the β-defensin gene, and as the name implies it plays a role in the synthesis of peptides with antimicrobial activity in the skin, assisting in its role as a barrier to infection. (Candile et al 2007, Hedrick 2009, Leonard et al 2012).
While breeders are struggling to manage a number of emerging health issues in this wonderful breed, it should be a matter of policy that the loss of genetic diversity for any reason should be minimized to the fullest extent possible. A genetic management plan that strategically prioritizes retaining genetic diversity through the breeding of dogs carrying less common alleles should be encouraged by the custodians of the breeds, and breeders that do this should be supported.
There are some other important things breeders can do to improve the future of this breed. It would be useful to do a breed-wide survey of genetic diversity using a genotyping service like Embark. This will provide information on both breed-wide and genomic inbreeding, the size of the gene pool, distribution and frequency of alleles for known mutations and traits (including color), and the potential presence of lineages of differing genetic composition that can be managed in a way to support retention of the genetic diversity currently available in the breed. These data can produce much information that would assist breeders interested in developing breeding plans that will improve the health of the breed as well as its highly valued qualities as a working dog and a companion. You can see examples of these types of analyses for a number of breeds using the ICB Breeder Tool at http://bit.ly/2OE88by, and ICB can assist you with this.
It would also be extremely useful to do a genetic analysis of a pedigree database. This will provide wealth of information about history that might not otherwise be known through other records. It can also reveal current breeding practices that are detrimental to the preservation of genetic diversity, allowing breeders to take steps that will provide more genetic stability and facilitate management of existing health issues. You can see an example of this type of analysis here (The amazing secrets hiding in your pedigree database). This analysis is for Afghan hounds, but it provides a good model of the wealth of information that can (and should) be extracted from a pedigree database with the appropriate software and expertise. ICB can provide this type of analysis, and it would be very worthwhile to do for this breed.
Cadille SI, CB, Kaelin, BM Cattanach and others. 2007. A β-defensin mutation causes black coat color in Domestic dogs. Science 318: 1418-1423.
Hedrick PW. Wolf of a different color. Heredity 103: 435-436.
Leonard, B. C., Marks, S. L., Outerbridge, C. A., Affolter, V. K., Kananurak, A., Young, A., ... Bevins, C. L. (2012). Activity, expression and genetic variation of canine β-defensin 103: A multifunctional antimicrobial peptide in the skin of domestic dogs. Journal of Innate Immunity, 4(3), 248-259. https://doi.org/10.1159/000334566