2013 Annual Report
1a.Objectives (from AD-416):
The specific objectives for this agreement are to 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):
The University will check for differential gene expression of targeted genes e.g., CD163, SIGLEC1, PTEN, MMP9, IL10, FOXP3, TBET, GATA3, CCL21, MX1, etc., using RT-PCR on PRRS Host Genetics Consortium (PHGC) samples representing different virus/weight categories. This information that will be used in conjunction with analyses collected on the same sample sets at Michigan State University and BARC. For the third objective, the University will help identify and provide samples collected from recent U.S. PRRS infections.
Our goal is to determine which anti-viral response pathways differ in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV), a major swine pathogen causing losses to the US pig industry of $664 million per year. This functional genomics project uses samples collected as part of the PRRS Host Genetics Consortium (PHGC). ARS researchers at Beltsville, Maryland (BARC) have partnered with Purdue University scientists to identify genes expressed at different levels in resistant versus susceptible pigs. This research is coupled with microarray work performed at Michigan State University (MSU) and biostatistical and bioinformatic analyses at MSU and Iowa State University. At Purdue University scientists used quantitative PCR analyses to affirm gene expression of targeted genes e.g., the PRRSV receptors and critical genes controlling immune anti-viral responses. As this work progresses we expect to develop predictions of pathways and classifier genes that are consistently over- or under-expressed in pigs which resist PRRSV infection and grow normally.