Association analysis between pseudorabies antibody and five single-nucleotide polymorphisms in pigs.

Pseudorabies has become endemic and represents a widespread problem for pig production in the world, causing great economic losses associated with reproductive failure and neonatal mortality in the pig industry. Most diseases are the results of mutations of functional genes. Single-nucleotide polymorphisms (SNPs) from the coding regions of the mediators of pro-inflammatory responses or other candidate genes in pigs could indicate their potential involvement in susceptibility or resistance to PrV (pseudorabies virus) infection. There have been no previous association studies with candidate host genes that may influence PrV phenotypic traits. In order to perform association studies to identify genes contributing to PrV phenotypes, the genotypes of five SNPs from four genes (IL10, CXCL12, BAT2 and EHMT2) were determined for 178 sow samples using a high throughput microarray-based methodology. PrV antibodies were tested by enzyme-linked immunosorbent assay (ELISA) to determine whether there was an association between antibody levels and particular genotypes. The association between SNP genotypes and the PrV antibody levels were analysed using the Duncan method of one-way ANOVA procedure using the SAS (Statistical Analysis Systems) software package. The results showed that the glycoprotein E-ELISA antibody level of pigs with genotypes 11(AA) and 12(AG) was significantly higher than in pigs with genotype 22(GG) (P < 0.05) of SNP in the gene EHMT2-SNP2. The SNP of EHMT2 may be an effective potential tool to identify susceptible and resistant animals when used in conjunction with traditional selection methods.