The Basics of Coat Color Genetics for the Kerry Blue and the Soft Coated Wheaten Terriers
by Neil O'Sullivan <firstname.lastname@example.org>,
Copyright © 2003 Kerry Blue Terrier Foundation
The pictures you see here are from purebred but mis-marked Kerries. They were provided to me on conditions of anonymity. The breeders of these terriers are well known in their countries and these photos should not reflect negatively on the quality of their breeding lines.
These color abnormalities are very rare and probably could not be duplicated.
Thanks to all who have contributed to this page.
If you have additional pictures, please e-mail them to email@example.com.
The black coat a Kerry is born with is the result of the A A genotype and it is dominant to the a/y a/y wheaten coat. A low percentage of Kerries still carry the a/y allele and when two A a/y Kerries are bred up pops the wheaten colored Kerry. No solid black Wheatens are born from wheaten (a/y a/y) colored parents.
The Kerry develops the gray color with age due to the action of the dominant G allele. Wheatens segregate for the G and g allele as both gray and black ears can be seen in the Wheaten. Kerries also segregate for the c/ch allele resulting in the lighter more silver Kerries and the darker more slate gray color. Wheatens also appear to segregate for these alleles of the C gene. In Wheatens we see poor nose and eye pigment along with a pale coat color associated with a allele c/ch which along with a paler coat we see the "winter nose" or poor pigmentation syndrome.
Wheatens do have black, at birth at least, on most puppies.
This is due to the interaction between the alleles of the E gene
and the a/y a/y genotype. Since Kerries are black - gray we can't
seen the expression of these alleles. Commonly Wheatens have the
self colored which is E allele and or the e/m or mask allele.
Black and tan (a/t) is in the A gene allele series and is recessive to both black (A allele) and the wheaten (a/y allele) colors. So black and tan puppies can and do occur in both Wheaten and Kerry litters. Albeit very, very rarely. I remember people being worried in the 1980 that a litter of Wheatens with black and tan puppies was caused by some "problem" with the pedigree. Not likely just the chance meeting of two Wheatens with the a/y a/t genotype.
In Wheatens we see fairly commonly the work of the B genes recessive dilation allele b . Wheatens bb in genotype are born with chocolate or brown where normally it would be black. Nose and eye rim pigment comes in brown instead of black. I don't recall reports of this allele (b) in the Kerry. They would have a coat brown or chocolate color at birth with brown nose and eye rim pigmentation as they mature. Eye iris color has always been much paler than normal on bb Wheatens.