Utility of canine microsatellites in revealing the relationships of pure bred dogs.

The variability of 19 canine microsatellite loci was examined within and between three pure breeds of dog. Their phylogenetic relationships were estimated by microsatellite and conventional genetic distances which indicated that greyhounds and German shepherds had longer diverse evolutionary histories, whereas Labrador retrievers were established much later. Our three breeds differ mainly in the relative frequencies of alleles at a locus and in distribution of alleles across loci. As a consequence of sampling strategy, greyhounds express significantly lower polymorphism than the other two breeds. However, some highly polymorphic microsatellite loci were common to all three breeds. High exclusion power of such loci made them valuable for parentage testing. Although the exclusion probability at a single locus is relatively low, it increases by every added microsatellite. The six most polymorphic ones sufficed to reach the exclusion probability of 99% in all three breeds tested here. As the majority of pedigree dogs have similar population structures, the data presented can be used to estimate the probability of biological paternity for any dog breed, despite the absence of appropriate population data. Polymorphic canine microsatellites proved to be valuable descriptors of population structure, and evolutionary and filial relationships.