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

The variability of 19 canine microsatellite loci was examined within and be tween three pure breeds of dog. Their phylogenetic relationships were estim ated by microsatellite and conventional genetic distances which indicated t hat greyhounds and German shepherds had longer diverse evolutionary histori es, whereas Labrador retrievers were established much later. Our three bree ds differ mainly in the relative frequencies of alleles at a locus and in d istribution of alleles across loci. As a consequence of sampling strategy, greyhounds express significantly lower polymorphism than the other two bree ds. However, some highly polymorphic microsatellite loci were common to all three breeds. High exclusion power of such loci made them valuable for par entage testing. Although the exclusion probability at a single locus is rel atively low, it increases by every added microsatellite. The six most polym orphic ones sufficed to reach the exclusion probability of 99% in all three breeds tested here. As the majority of pedigree dogs have similar populati on structures, the data presented can be used to estimate the probability o f biological paternity for any dog breed, despite the absence of appropriat e population data. Polymorphic canine microsatellites proved to be valuable descriptors of population structure, and evolutionary and filial relations hips.