Translational Genomics of Porcine Reproductive and Respiratory Syndrome (PRRS)

Our goal is to understand transcriptional control of viral disease responses focusing on the economically most important disease of pigs, porcine reproductive and respiratory syndrome (PRRS) (annual U.S. losses of $664M). The PRRS Host Genetics Consortium (PHGC) was established to combine efforts of scientists from university, government and commercial pig genetics and animal health companies to assess the role of genetics in determining pig resistance/ susceptibility to PRRS virus (PRRSV) infection, pathology and growth effects. We utilized a nursery pig PRRSV infection model with deep sampling for phenotypic analyses, extensive genotyping (60K SNPchip) and a shared database http://www.animalgenome.org/lunney/. We have completed 15 trials using ~200 PRRSV-infected pigs each and identified a genomic region on SSC4 which has a significant impact on variation in viral load and growth responses following challenge with each of 2 different PRRSV isolates. To address disease resistance mechanisms we probed the blood transcriptome of PHGC pigs using RNAseq. We have verified genes that are differentially expressed in PRRS resistant versus susceptible pigs. We are now expanding our efforts to probe for alternate control and regulatory networks by comparing pigs with differential PRRSV responses, i.e., those with slow or fast post viral peak control responses. This data will help us identify new resistance pathways that may be used for vaccine design and novel biotherapeutics. Support: US National Pork Board, USDA ARS and NIFA, Genome Canada, Genome Alberta, pig breeding companies.