Genomics Research Consortia: Addressing Animal Disease Problems from Phenotype and Genotype to Application

Research consortia can facilitate efforts to understand genomic control of complex traits such as disease responses in livestock that require concerted effort from numerous specialists. To address the economically most important disease of pigs, porcine reproductive and respiratory syndrome (PRRS) (annual losses of $664M), we organized the PRRS Host Genetics Consortium (PHGC), a national effort to assess the role of genetics in determining pig resistance/susceptibility to PRRS virus infection, pathology and growth effects. The PHGC is a unique, first-of-its-kind approach to food animal infectious disease research combining scientists from university, government and commercial pig genetics companies. By building on a well developed experimental plan, built by consensus with stakeholders, a nursery pig PRRSV infection model was established. This plan included deep sampling for phenotypic analyses, extensive genotyping (60K SNPchip) and a shared database http://www.animalgenome.org/lunney/. This public-private partnership completed experimental trials using large numbers of PRRS virus-infected pigs, statistically improving the ability to identify genotypes/phenotypes that predict resistance, tolerance or susceptibility to PRRS. Initial results from the PHGC have identified a genomic region that has a significant impact on variation in viral load and growth response following challenge. Combining efforts of US and Canadian researchers 2 PRRSV isolates have now been tested and research expanded from controlled infection trials to complex challenges and vaccine trials, as well as field trials of pigs predicted to be genetically resistant. Future data from commercial systems should help to validate effects and to explore the impact of selection for disease resistance on other traits.