Genetic diversity and phylogenetic relationships in feral pig populations from Argentina

Characterization of SNPs in meat quality-related genes in Argentine Coastal Creole pigs and their potential as a porcine genetic resource

The Coastal Creole pigs in Argentina are predominantly found in the wild and can trace their lineage directly back to the Iberian breeds introduced by Spanish colonizers. They currently stand as the sole Creole breed in the country recognized by the FAO. However, there exists a dearth of studies assessing their genetic potential within the swine industry. Therefore, this study aimed to genetically characterize the meat quality of Coastal Creole pigs based on seven single nucleotide polymorphisms (SNPs) within the Ryr1, PRKAG3, MC4R, H-FABP, and CAST genes. A total of N = 158 samples were collected from specimens distributed along the coastal region. Our findings revealed all loci to exhibit polymorphism, underscoring the population's remarkable genetic diversity. Furthermore, a higher frequency of alleles favorable for the PRKAG3191I>V/200R>Q, MC4R1426A>G, CAST76872G>A, and Ryr11843C>T genes was observed, while alleles unfavorable predominated for H-FABP1811G>C and CAST638Ser>Arg. The results obtained in this research are highly encouraging, reflecting the genetic potential of these pigs to be utilized in swine production programs.

Genetic characterization of domestic pigs in the core zone of swine production of Argentina

Argentina is a small player in the global pork market, contributing only 0.7% of the total production. With increasing global demand for meat, there is an opportunity for countries with an agricultural profile to grow their pork production. However, there is a need to understand the current state of the pork production sector in all aspects to inform decision-making. The aim of this study was to genetically characterize pig herds from different production strata in the primary region for pork production in the country. For this purpose, phylogenetic and genetic variability analyses were performed using the mitochondrial control region marker (n=95 pig samples). Moreover, genotyping of ryr1 and PRKAG3 genes (n=108 pig samples) were performed to evaluate the frequency of deleterious alleles for meat quality traits in the region. The results showed high levels of genetic variability in the pig herds (Hd= 0.840 ± 0.031 and π= 0.010 ± 0.001), with a creole sow and Iberian lineage standing out in the phylogeny. The genotyping of the ryr1 marker revealed the presence of the deleterious t allele in all analyzed strata. However, the RN-allele of the PRKAG3 gene was detected only in the two lower strata. This study represents the first analysis of the phylogenetic relationships among domestic pigs from Argentina and provides an initial assessment of genetic variability in the region. Additionally, the results present, for the first time, the frequency of deleterious alleles for pig production in the productive core area, demonstrating their prevalence.

Patterns of genetic variation on wild pig (Sus scrofa) populations over a complete range of the species in Argentina

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.

Wild pigs (Sus scrofa) population as reservoirs for deleterious mutations in the RYR1 gene associated with Porcine Stress Syndrome

Porcine Stress Syndrome (PSS) is a disorder codified by the ryanodine receptor 1 gene (RYR1) and affects both animal welfare and the quality of the meat product. As a consequence, individuals with this syndrome generate great worldwide economic losses in the porcine industry. In Argentina, the Buenos Aires Province is the most involved on this activity, and productions are to be in open field with a higher frequency of pigs with diverse pathologies. On the other hand, the biggest and oldest wild pigs population is located on the Atlantic coast of Buenos Aires Province, which presents a continuous bidirectional flow of individuals with the productive areas nearby. The aim of this study is to detect the presence of the RYR1 deleterious allele in the wild population from the Atlantic coast of Buenos Aires, in order to evaluate its possible role as a genetic reservoir for said allele. For this purpose, 106 wild pigs from 28 sites were studied, finding a 6.6% of carrier individuals, indicating that the wild population is not free of this allele. This constitutes the first analysis to detect the presence of the RYR1 deleterious allele, associated to the PSS in wild pigs from Argentina, being one of the few studies to report it worldwide and suggesting wild pigs populations to be a possible genetic reservoir for this disease.