ARS | Publication request: Discovering regions of the bovine genome associated with variation in the immune response

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2011
Publication Date: March 19, 2012
Citation: Leach, R.J., Glass, E.J., Kuehn, L.A. 2012. Discovering regions of the bovine genome associated with variation in the immune response [abstract]. Journal of Animal Science Supplement. 90 (Supplement 2):24 (Abstract No. 62).

Technical Abstract: Infectious disease of livestock continues to be a cause of substantial economic loss and adverse welfare. Breeding for disease resistant livestock could improve both the economic burden and animal welfare. Using genetic linkage and association methods, we aim to identify key genes and pathways that control variation in immune response; knowledge that may aid both breeders and vaccinologists. The second generation of the RoBoGen herd (a Charolais Holstein F2 backcross, n = 982) were phenotyped for immune responses (total IgG responses) to a Bovine Respiratory Syncytial Virus (BRSV) vaccine (n = 467) across several time points. Considerable variance in immune responses enabled detection of QTL using 165 equally spaced microsatellite markers genotyped genome wide. Further genotyping of the F2 animals in these regions using non-synonymous SNP (n = 274) increased resolution to detect linkage disequilibrium associations. A Genome wide association study which used the SNP indicated that several regions of the bovine genome play a significant role throughout the immune response to the BRSV vaccine. A second population (MARC III, a composite population, n = 3,500) have been vaccinated for BRSV, PI3, BVDV and IBR. Immune phenotypes, such as IgG and lung score, have been measured. Every animal in the herd is also genotyped with at least 50K SNPs. Using both herds, regions associated with the immune response have been discovered and genetic variance components have been estimated. Regions such as the Major Histocompatibility Complex (MHC) on chromosome 23 and the Toll-like Receptor Cluster 1/6/10 on chromosome 6 have been highlighted. We conclude that key pivotal pathways may be shared in eliciting and maintaining an immune response to differing types of antigens.