Use of RAPD technique in evolution studies of four species in the family Canidae

The RAPD-PCR technique was applied to identify genetic markers able to distinguish between four canid species: the arctic fox (Alopex lagopus), red fox (Vulpes vulpes), Chinese raccoon dog (Nyctereutes procyonoides procyonoides) and six breeds of the domestic dog (Canis familiaris). A total of 29 ten-nucleotide arbitrary primers were screened for their potential use in the differentiation of these species. Ten primers amplified RAPD profiles that made it possible to distinguish between the investigated taxa. A number of species-specific bands was scored within RAPD profiles produced by these primers: 35.6% of all the polymorphic bands were unique to the Chinese raccoon dog, 29.6% were unique to the domestic dog, 21.2% were diagnostic for the red fox and 13.6% for the arctic fox. No breed-specific fragments were amplified from canine DNA; however, three primers produced bands characteristic for the dog, but not present in all of the investigated breeds. A Neighbor-Joining tree constructed on the basis of the analysis of RAPD profiles amplified by six primers revealed that the phylogenetic distance between the dog and the arctic fox is larger than the distance between the dog and the red fox. The phylogenetic branch of the Chinese raccoon dog was the most distinct on the dendrogram, suggesting that this species belongs to a different phylogenetic lineage. Obtained results make it possible to conclude that RAPD analysis can be a powerful tool for developing molecular markers useful in distinguishing between species of the family Canidae and for studying their phylogenetic relations.