The Devon Rex breed produces a curly coat and the Sphynx breed is nearly hairless. The nearly hairless coat of the Sphynx breed is recessive to normal coat, and the curly coat of the Devon Rex breed is recessive to the hairless Sphynx coat.
Alleles: N = Normal coat, HR = Sphynx hairless, DR = Devon Rex curly
Breeds appropriate for testing: Sphynx, Devon Rex
Explanation of Results:
Cats with N/N genotype will have normal coats. They cannot transmit this hairless variant or this Devon Rex variant to their offspring.
Cat with N/HR genotype will have normal coats, but are carriers of the hairless variant. They will transmit this hairless variant to 50% of their offspring. Matings between two carriers of the Sphynx hairless variant are predicted to produce 25% hairless kittens.
Cats with N/DR genotype will have normal coats but are carriers of the Devon Rex curly variant. They will transmit this curly variant to 50% of their offspring. Matings between two carriers of the Devon Rex curly variant are predicted to produce 25% Devon Rex curly-coated kittens.
Cats with HR/HR genotype will be hairless. They will transmit this hairless variant to all of their offspring.
Cats with DR/DR genotype will have curly coats. They will transmit this Devon Rex curly variant to all of their offspring.
Cats with HR/DR genotype will be hairless but do not "breed true" to the hairless phenotype; they can produce normal, hairless, or curly coated offspring depending on the genotype of the cat they are bred to.
Domestic cats have a variety of coat colors and hair types. Long and short hair phenotypes are common, but there are also other mutations that produce curly and nearly hairless coats. Two of the breeds of cats derived from such mutations are Devon Rex, a curly coat variety that appeared in 1959, and the nearly hairless breed Sphynx, which originated from another mutation in 1966.
Research from Dr. Leslie Lyons’ lab at the University of California, Davis (now at University of Missouri) demonstrated that these 2 mutations are in the gene Keratin 71 (KRT71). The nearly hairless coat of the Sphynx breed is recessive to normal coat, and the curly coat of the Devon Rex breed is recessive to the hairless Sphynx coat.
Testing for the Sphynx hairless and Devon Rex curly mutations assists breeders in determining if a cat carries these mutations. For breeders of Sphynx, the tests identify hairless cats that carry the Devon Rex mutation and would not breed true for the hairless phenotype depending on the genotype of the mate.