In Argentina, domestic pigs (Sus scrofa Linnaeus 1758) were introduced during the first Buenos Aires foundation, in the year 1536. Their provenance was mainly from the Iberian Peninsula, the Canary Islands and Cape Verde. In 1541 those pigs were released and, consequently, the first feral populations were originated. Thereafter, the species propagated both naturally and through human action, reaching a distribution that covers most of the Argentinian territory. The objective of this study is to genetically characterize the oldest feral pig populations in Argentina, making use of the mitochondrial control region (CR) and the amelogenin gene (AmelY), in order to determine their phylogenetic origin and corroborate its consistency with the historic information. The obtained results indicate that most of the feral pigs in Corrientes and Buenos Aires populations are positioned in the European subclades, E1-A and E1-C for CR, and HY1 and HY2 for AmelY. Despite this fact, a low frequency of individuals of Asian origin was found in populations from Buenos Aires, whereas none of them disclosed African ancestry. Furthermore, given that a large proportion of feral pigs found in the species' original sites in Argentina have European ancestry, we can partially corroborate the historical records.

The Eurasian wild boar (Sus scrofa Linnaeus, 1758) was introduced into Argentina at the beginning of the twentieth century when individuals from Europe were taken to La Pampa province for hunting purposes. Starting from there, a dispersal process began due to the invasive characteristics of the species and to human-mediated translocations. The main objective of this study was to characterize for the first time, the phylogenetic relationships among wild boars from Argentina with those from Uruguay, Europe, Asia, and the Near East, along with diverse domestic pig breeds in order to corroborate the historical information about the origin of the local populations. To this end, we used mitochondrial Control Region and Cytochrome b sequences from sampled Argentinian wild boars and retrieved from GenBank. The results showed that the majority of the Argentinian wild boar populations descend from European lineages, in particular of the E1 clade, according to the historical records. Remarkably, the population of El Palmar National Park had Asian origin that could be attributed to hybridization with local domestic pigs or to unrecorded translocations. Finally, genetic diversity in Argentinian populations was lower than in Europe and Uruguay meaning that wild boar in Argentina is still under the influence of founder effect and has experienced minor genetic introgression from domestic pigs, representing in this sense a reservoir of the original wild boar genetic variability.

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In Argentina, wild pigs (Sus scrofa) are represented by wild boars and feral pigs. These populations inhabit a wide territory due to natural dispersion and human translocation. Previous studies in other countries have detected crossbreeding between the different morphotypes, even with domestic pigs. This crossing can lead to introgression of improved traits in the wild population, which would increase the invasive potential and, therefore, the damage to native ecosystems. The aim of this work was to obtain the patterns of genetic variability throughout its current distribution in Argentina, in order to elucidate genetic relationships between wild boar and feral pig populations through the molecular marker control region. For this purpose, studies of genetic variability and population structure were carried out using 377 sequences from Argentinian wild pigs. The high values of haplotype and nucleotide diversity (Hd = 0.866 and π = 0.00959) obtained, and the cluster analyses (SAMOVA and BAPS) could indicate mixing between wild pigs and/or with domestic pigs. The star-like shapes observed in the haplotype network and neutral tests (Fu’s Fs and Tajima’s D) are consistent with a recent population expansion, supporting previous reports that indicate crossbreeding increases invasive potential.