Breed differences in the phenotype and gene frequencies in canine D blood group system.

The D system of canine blood groups was studied in 3,191 dogs of many different breeds. The frequencies of the D system phenotypes and genes were measured. These frequencies varied considerably between the breeds native to Japan. The frequency of the D1 phenotype was higher in breeds native to Japan than in those of non-Japanese origin. Conversely, non-Japanese breeds generally had the D2 phenotype. The dogs described as mongrel in Japan had D system frequencies intermediate between native Japanese and non-Japanese breeds. One of the most interesting findings was that in the Afghan bound the frequency of the D1 gene (0.3333) was the same as in the Shiba, though only the Shiba was native to the Japanese isles. Another Japanese breed was the Tosa, and its D1 gene frequency was 0.063, a value even lower than that for the non-Japanese Maltese (0.097).