Genomic organization and polymorphisms detected by denaturing high-performance liquid chromatography of porcine SLC11A1 gene

Association of natural resistance-associated macrophage protein 1 polymorphisms with Salmonella fecal shedding and hematological traits in pigs

Background and Aim

Natural resistance-associated macrophage protein 1 encoding gene (Nramp1) plays a role in immune response and disease resistance. This study aimed to investigate the polymorphisms of Nramp1 intron 6 concerning Salmonella shedding and hematological traits in pigs.

Materials and Methods

A total of 40 commercial pigs (three-way Large White x Landrace x Duroc cross) were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and analyze the relationship between the polymorphisms of the Nramp1 gene and Salmonella fecal shedding and hematological parameters.

Results

Nramp1 was shown to be polymorphic in these pigs. The Nramp1 gene has two alleles (A and B) and two genotypes (AB and BB). The BB genotype had a higher frequency than the AB genotype. A significant relationship between the BB genotype and the number of Salmonella in feces compared to the AB genotype (p < 0.05) on 7 days post-inoculation (DPI) was revealed in the association analysis. The single-nucleotide polymorphism at intron 6 in the Nramp1 gene was linked to white and red blood cells 2 and 7 DPI (p < 0.05).

Conclusion

The Nramp1 gene was suggested by these findings to be potentially used as a molecular marker for the genetic selection of disease susceptibility in pig breeding.

Association of Fut1 and Slc11a1 gene polymorphisms with productivity traits of Large White pigs

The purpose of our work was to study the polymorphism of genes associated with disease resistance and to search for their associations with productive traits in the population of the Ukrainian Large White pigs. For this study, 50 pigs were used, observations and measurements were carried out at the age from birth to 180 days. Genetic studies were carried out in a certified laboratory of the Institute of Pig Breeding and Agroindustrial Production. In the study of fucosyltransferase 1 and solute carrier family 11 member 1 genes, polymorphism was found in three of the five analyzed loci. In the Ukrainian Large White subpopulation of pigs the informativeness of these gene polymorphisms was at the optimal level for associative analysis, Polymorphism Information Content was greater than 0.3 in two loci. A sufficiently high level of Polymorphism Information Content indicates the value of this breed to preserve the biodiversity of pigs. The distribution of genotypes at some loci of the solute carrier family 11 member 1 gene was characterized by a deviation from the theoretically expected one due to the increase in the frequency of the heterozygous genotype. There was also a statistically confirmed deviation of the genotypes’ distribution from the normal and polymorphism fucosyltransferase 1 gene, but in this case in the direction of increasing the frequency of both homozygous variants. These results indicate the presence of a certain selection pressure on the mentioned polymorphisms and their possible impact on productive traits. The influence of solute carrier family 11 member 1 gene polymorphism on the weight of pigs at the age of 120 and 180 days, the average daily gain recorded in the period 28–120 days and from birth to 180 days, as well as on the backfat thickness, was established. The preferred genotype is TT, which can be used in breeding to obtain more productive animals with increased disease resistance, but in the selection of animals at this locus, it is necessary to control the backfat thickness and prevent breeding of pigs that may worsen this trait.

Single nucleotide variants in innate immune genes associated with Salmonella shedding and colonization in swine on commercial farms

Foodborne human salmonellosis is an important food safety concern worldwide. Food-producing animals are one of the major sources of human salmonellosis, and thus control of Salmonella at the farm level could reduce Salmonella spread in the food supply system. Genetic selection of pigs with resistance to Salmonella infection may be one way to control Salmonella on swine farms. The objective of this study was to investigate the association between genetic variants in the porcine innate immune system with on-farm Salmonella shedding and Salmonella colonization tested at slaughter. Fourteen groups of pigs (total 809) were followed from birth to slaughter. Fecal samples collected five times at different stages of production and tissue samples obtained from tonsil and lymph nodes at slaughter were cultured for Salmonella. Genomic DNA was extracted and analyzed for 40 single nucleotide variants and two indels within porcine innate immune genes that were previously associated with Salmonella infection or other infectious diseases. A survey was used to collect information on farm management practices. A multilevel mixed-effects logistic regression modelling method was used to identify SNVs that are associated with Salmonella shedding and/or Salmonella colonization. One single nucleotide variant in the C-type lectin MBL1 and one single nucleotide variant in the cytosolic pattern recognition receptor NOD1 was associated with increased risk of on-farm shedding (p = 0.010) and internal colonization tested at slaughter (p = 0.018), respectively. These findings indicate the potential of these variants for genetic selection programs aimed at controlling Salmonella shedding and colonization in pigs.