Genetic diversity of wild boar populations and domestic pig breeds (Sus scrofa) in south-western Europe

The Eurasian wild boar, Sus scrofa, is an important game species and is widely distributed in Eurasia. The recent
demographic expansions allied to man mediated translocations and reintroductions, reshaped the genetic variability
of wild boar populations, and gave rise to management problems. Genetic variability and the population
structure of the European populations are not well-known, in particular in the Iberian Peninsula. In the present
study, we assessed the phylogenetic relationship among 17 Iberian wild boar populations and several Eurasian wild
and domestic pigs by sequencing 660 bp of the mitochondrial (mt)DNA control region. This analysis was extended
to the two autochthonous Portuguese pig breeds, Bísaro and Alentejano, and their relationship with Eurasian pigs
was also established. High levels of gene diversity were found in Iberian wild boar and Portuguese domestic pigs,
as well as a significant genetic difference among and within populations. Iberian wild boar and Portuguese pig
breeds belong to the main European clade but diverge with animals from Central Europe, showing a high
proportion of private (Iberian) haplotypes. These results suggest the existence of glacial refugia for Sus scrofa in
the Iberian Peninsula during the Last Glacial Maximum. No signs of Asian mtDNA introgression from Asian
populations were found in the present survey.