Assessment of the population structure of five Finnish dog breeds with microsatellites

Genetic variabilities within and between Finnish populations of Golden Retr ievers, German Shepherds, Wirehaired Dachshunds, Pembroke Welsh Corgis and Bedlington Terriers were quantified with microsatellite allele numbers, obs erved heterozygosities, expected heterozygosities, F-IS estimates, F-ST est imates and D-S distances. In a sample of 50 individuals from each breed and ten polymorphic loci, the highest genetic diversity was exhibited in the W irehaired Dachshunds and lowest in the Bedlington Terriers. Although statis tically significant deviations from the Hardy-Weinberg (H-W) equilibrium we re observed, they occurred at an unexpectedly low frequency. Most strikingl y, the extremely small Bedlington Terrier population displayed genotypes in H-W proportions in all investigated loci. The H-W deviations always occurr ed with positive F-IS estimates, which, on average, were not larger than va lues reported for free-living canids. Genetic differentiation between the b reeds was very large. As a comparison, present estimates were, on average, over two times higher than previously observed between breeds of sheep, and over two times higher than the highest estimates reported between human po pulations. Moreover, the highest D, distances were only slightly lower than the lowest values inferred between humans and chimpanzees. Severe bottlene cks in the recent past of the examined breeds were not statistically suppor ted. The presented data imply genetic isolation and intense artificial sele ction in the history of these breeds of dogs.