a report to the Cardigan Welsh Corgi Club of America
April 3, 2005
Introduction Over the past year, Sue Buxton, as the Health Representative for the Cardigan Welsh Corgi Club of America, has helped contact dog owners for a study of coat color in this breed. Several individuals have contributed DNA cheek brush samples and photos of their dogs and we appreciate this very much. A few have also contributed whole litters. Although the study is not complete in the sense that the genes for all patterns and colors have not been found, we have made some progress and this report will explain the status of our findings to date.
The E locus
Pepper – EE red
Melanocortin Receptor 1 (MC1R) is the gene at the E locus. Dogs have 3 alleles at this locus: EM, E, and e. All three occur in Cardigans. Pepper is E/E at this locus. Most people would call Pepper “red” but she is a reddish color because she has an ay allele. She has no melanistic mask.
Maizey – EM/E
Honey – EM/E
Honey and Maizey are both EM /E. Athough the EM allele is dominant, Honey does not show a melanistic mask though either! Since most Cardigans have the characteristic white undersides, necklace and muzzle…..the melanistic mask doesn’t show. This is proof that the white is caused by a loss of pigmentation, as is typical of most forms of white. Maizey has a hint of a mask on her cheek. Other modifier genes cause the difference in the tone of red or the relative amount of black hairs in the red coat as demonstrated by Honey and Maizey. Some breeders thought that the darkness of a dog like Maizey meant she was ay/at, but actually so are Honey and Pepper!