Identification of QTLs and Genes Related to Immune Response to Poly (I:C) Stimulation in a Duroc-Erhualian F2 Pig Population

A number of QTL studies have been conducted in the pig, but limited studies focused on anti-viral immune response. In this study, identification of candidate genes, QTLs / eQTLs for anti-viral immune response in the pig were performed in a Duroc-Erhualian F2 population. Poly (I:C), a synthetic analog of double-stranded RNA, which can induce interferon and enhance the capability of disease resistance to various viral pathogens, were used to trigger the potential immune capability for each F2 pig. The resource population consists of 392 F2 pigs. For each F2 pig, blood samples were harvested by jugular venipuncture at 20, 33 and 35 days old. The stimulation with 0.5mg/kg poly (I:C) for each pig at 4 hours before drawing blood at 35 days old. Hematological parameters, blood T-cell subgroup and serum cytokines were measured for all samples. All the F2 and F1 pigs were genotyped by Illumina porcine 60k SNP chips. Interesting chromosome regions harboring QTLs for some T-cell subgroup traits were found. Transcriptomic comparison of Duroc-Erhualian F2 pigs with extreme serum Interferon-alpha responses to poly (I:C) was conducted. A total of 1700 genes showed significant differential expression (q<0.05)between pre/post-poly (I:C) treatment porcine blood in high level serum Interferon-alpha response F2 pigs, while most of these genes did not show differential expression in low serum Interferon-alpha responders. Further analysis is ongoing for eQTL mapping.