On the origin of a domesticated species: Identifying the parent population of Russian silver foxes (Vulpes vulpes).

The foxes at Novosibirsk, Russia, are the only population of domesticated foxes in the world. These domesticated foxes originated from farm-bred silver foxes (Vulpes vulpes), whose genetic source is unknown. In the present study, we examined the origin of the domesticated strain of foxes and two other farm-bred fox populations (aggressive and unselected) maintained in Novosibirsk. To identify the phylogenetic origin of these populations we sequenced two regions of mitochondrial DNA, cytochrome b and d-loop, from 24 Novosibirsk foxes (eight foxes from each population) and compared them with corresponding sequences of native red foxes from Europe, Asia, Alaska and Western Canada, Eastern Canada, and the Western Mountains of the USA. We identified seven cytochrome b-d-loop haplotypes in Novosibirsk populations, four of which were previously observed in Eastern Canada. The three remaining haplotypes differed by one or two base change from the most common haplotype in Eastern Canada. Theta(ST) analysis showed significant differentiation between Novosibirsk populations and red fox populations from all geographic regions except Eastern Canada. No haplotypes of Eurasian origin were identified in the Novosibirsk populations. These results are consistent with historical records indicating that the original breeding stock of farm-bred foxes originated from Prince Edward Island, Canada. Mitochondrial DNA data together with historical records indicate two stages in the selection of domesticated foxes: the first includes captive breeding for approximately 50 years with unconscious selection for behaviour; the second corresponds to > 50 years of additional intensive selection for tame behaviour. (C) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103, 168-175.