Project Number: 1265-32000-084-00
Project Type: Appropriated

Start Date: Nov 18, 2006
End Date: Nov 17, 2011

Objective:
The goals of this research are to evaluate the host pathogen relationship using genomics and immunologically-based approaches, and use this information to develop methods that complement and/or reduce drug intervention as a means to control gastrointestinal (GI) nematodes of cattle. In this regard, we will identify structural variations in the bovine genome that influence host resistance to GI nematodes, pinpoint functional and/or structural variations in parasite genes associated with the drug resistant phenotype, identify and enhance immune factors that regulate the host-pathogen interface as an alternative to anthelmintic treatment, and finally use this collective knowledge to develop integrated parasite control programs that incorporate marker-assisted selection schemes that reduce economic loss caused by the parasites. These goals will be attained through a systems-based approach that will employ molecular, immunological, and genomic techniques to studies at the gene, cell and whole animal levels.

Approach:
Studies will focus on using genomic approaches to develop novel means to control parasitic diseases in cattle, and on-farm application of these techniques. These studies will investigate both the parasite genome and the host genome. Studies focusing on the parasite will evaluate genetic factors associated with drug-resistant and drug-susceptible phenotypes in parasitic nematodes. Investigations of the host genome will focus on the identification of host genetic loci that affect resistance to parasite infection and will develop and implement genome-wide selection or marker-assisted selection programs based on high density SNP information. Additionally the project will use SNP haplotypes to refine and characterize QTL for parasite resistance that were identified in earlier studies. At the same time studies will continue to characterize the host immune response to parasitic infection using microarrays and real time PCR to discern gene expression patterns in cattle demonstrating different levels of resistance and/or immunity to the parasites. Finally, the information gleaned from these studies will be applied on-farm through co-operative research efforts with producers to establish practical management programs to control and diminish the effects of parasites on production effeiciency.