Novel polymorphism of the canine dopamine receptor D4 gene intron II region
Various dog breeds are remarkably different from each other not only in their sizes and shapes but also in behavioral traits, suggesting that some of these characteristics are under genetic control. However, little is known about genes related to behavioral traits in canine species. In humans, it has been reported that the dopamine receptor D4 gene (DRD4) includes polymorphism at several regions that relate to personality or psychiatric disorders. In an earlier study by the authors of the present study, the polymorphisms in canine DRD4 exon III and exon I regions were reported. In the present study, a novel polymorphism in canine DRD4 intron II was found based on a 17 base pair insertion/deletion, and the two alleles detected were named P (shorter allele) and Q (longer allele). The allelic distribution in 28 breeds of dog, including a total of 1114 unrelated individuals, were then investigated. Both P and Q alleles were detected in most of the breeds investigated; however, the frequencies of P and Q differed greatly between breeds. With respect to classification based on breed origin, P and Q alleles were frequent in Occidental and Oriental breeds, respectively. Furthermore, two subspecies of wolves, the ancestors of dogs, were analyzed for the comparison of allele frequencies with dogs, and the P allele was predominant in both European and Chinese wolves.
Document Type: Rapid Communication
Affiliations: 1: Faculty of Applied Biological Sciences, Gifu University, Gifu-shi, 2: National Institute of Animal Health, Tsukuba-shi, 3: Istituto Nazionale per la Fauna Selvatica, Ozzano dell’ Emilia, Italy, and 4: College of Natural Sciences, Pusan National University, Pusan and 5: College of Natural Sciences, Kyungpook National University, Taegu, Korea 6: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku and 7: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, 8: Livestock Improvement Association of Japan, Maebashi-shi and 9: Faculty of Agriculture, Shinshu University, Minamiminowa-mura, Nagano-ken, Japan,
Publication date: February 1, 2005