Variation of short tandem repeats within and between species belonging to the Canidae family

Frequency distribution and allele size in 20 canine microsatellite loci were analyzed in 33 flat-coated retrievers, 32 dachshunds, 10 red foxes, and 10 Arctic foxes. Overall, the major difference between the two dog breeds was the relative allele frequencies rather than the size ranges of alleles at the individual locus. The average heterozygosity within the two dog breeds was not significantly different. Since the average heterozygosity at several polymorphic loci is a relative measure of heterogeneity within the population, analysis of heterozygosity within microsatellite loci is suggested as a measure for the diversity of populations. Eighty percent (16 of 20) of the canine microsatellite primer pairs amplified corresponding loci in the two fox species. This reflects a very high sequence conservation within the Canidae family relative to findings in, for instance, the Muridae family. This indicates that it will be possible to utilize the well-characterized fox karyotype instead of the dog karyotype as a step towards physical mapping of the dog genome. Analysis of exclusion power and probabilities of genetic identity between unrelated animals by use of the seven most informative loci demonstrated that it will be possible to assemble a panel of microsatellite loci that is effective for parentage analysis in all breeds.