Tissue expression, polymorphism identification of IL10 gene and their relationship with serum IL10 level in pigs

Interleukin 10 (IL10) gene is a pleiotropic cytokine that plays an essential role in cell-mediated immunity and humoral immunity. In this study, in order to better understand the effects of IL10 gene on serum IL10 concentration in pig, we firstly identified the genomic structure of porcine IL10 gene, revealed its mRNA tissue expression patterns, the polymorphisms of exons region of IL10 gene also were found, and then further association analysis of SNPs with serum IL10 level were carried out in 302 piglets from three pig populations. The 4,770bp porcine IL10 genomic DNA contains a total of 175 amino acids in the putative IL10 protein. The alignment and phylogenetic analysis of porcine IL10 amino acid sequences with their homologies of other species displayed high identity. IL10 mRNA was widely expressed in nine analyzed tissues by RT-PCR. Totally three SNPs of IL10 gene were identified by directly sequencing of PCR fragments, two SNPs (HQ026020:g.474C>T; 484T>A) were in exon3 and the other one (HQ026020:g.3164G>A) was in exon5 region. Our statistic analysis results showed that the SNP (HQ026020:g.474C>T) had highly significant association with serum IL10 level at day 35 (P<0.01) and the SNP (HQ026020:g.3164G>A) also was significantly associated with serum IL10 level at both day 20 and day 35(P<0.05). All these results will help our further understanding of biological functional of porcine IL10 gene in immune response and also indicated that IL10 gene may be used as a genetic marker with effects on serum IL10 level in the pig disease resistance breeding.