1a.Objectives (from AD-416):
The specific objectives of this agreement includes Identify differentially expressed (DE) genes in blood in response to PRRSV infection. Determine putative gene sets and pathways that predict a pig's ability to clear PRRSV infection and maintain weight gain; and Validate utility of gene sets and pathways for prediction of responsiveness to PRRSV infections in multiple populations. Predictive blood tests of pigs with improved PRRS disease resistance and growth maintenance; increased understanding of mechanisms involved in pig responses to PRRSV infection; scientific publications.
1b.Approach (from AD-416):
Michigan State University (MSU) researchers will contribute to the first two objective through developing statistical methods for selecting samples for evaluation from Tempus tube preserved blood samples collected through the PRRS Host Genetics Consortium (PHGC) representing pigs in different virus/weight categories. Perform all the microarray work and transcriptional profiling for the first two objectives and analyze all microarray data (processing and normalization and use of statistical programs to identify DE genes). MSU researchers will also collaborate on planning analysis of DE gene QPCR data (generated by USDA ARS BARC) for all Objectives.
By comparing anti-viral responses of resistant versus susceptible pigs we are identifying biomarkers expressed by pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV), a major swine pathogen which causes $664 million per year losses to the U.S. pig industry. ARS Researchers at Beltsville, Maryland, partnered with Michigan State University (MSU) scientists to identify genes expressed at different levels in resistant versus susceptible pigs. Microarray data was evaluated at several timepoints from blood samples collected as part of the PRRS Host Genetics Consortium (PHGC). MSU and Iowa State University scientists used sophisticated statistical tools to generate informative gene networks that differentiate the PRRSV response patterns in pigs representing different virus/weight categories. As a result a list of differentially expressed genes was compiled and used to identify genes and pathways that differentiate PRRSV response patterns of resistant versus susceptible pigs. Future work will validate, with specific assays, which of these genes and pathways are consistently over- or under-expressed in pigs that exhibit greater resistance to this important virus.