High genetic distinctiveness of wild and farm fox (Vulpes vulpes L.) populations in Poland: evidence from mitochondrial DNA analysis

In Poland, the number of wild red foxes (Vulpes vulpes L.) and the size of the fur-farming industry are growing. There is concern that the gene pool of the wild foxes is being infiltrated by that of the farm animals. We analyzed three groups-Polish farm foxes and wild-living animals from Poland and North America-to investigate the gene flow or introgression between farm and wild red foxes. We took into account the breeding history of the species and the evolutionary relationships between fox populations on different continents. We compared the haplotypes based on the concatenated nucleotide sequences of MT-CO1 (mitochondrially encoded cytochrome c oxidase I) and MT-ATP6 (mitochondrially encoded ATP synthase 6) genes. It was confirmed that investigated fur-farm animals originated from wild individuals living in North America. We found a haplotype common to wild foxes from Europe (Poland) and wild North American individuals. The common haplotype shared by both investigated wild-living groups could indicate some degree of introgression between Polish farm and wild-living populations. Haplotypes characteristic of North American foxes were transferred to the Polish wild population and have been established. However, the pairwise Phi(ST) values make it clear that North American wild and Polish wild foxes are genetically distinct evolutionary groups.