|SILVA, MARCOS - Embrapa|
|MATUKUMALLI, LAKSHMI - George Mason University|
|Schroeder, Steven - Steve|
|GASBARRE, LOUIS - Retired ARS Employee|
|Van Tassell, Curtis - Curt|
Submitted to: International Symposium on Animal Genomics for Animal Health
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2010
Publication Date: 5/31/2010
Citation: Sonstegard, T.S., Silva, M.V., Kim, E., Matukumalli, L.K., Schroeder, S.G., Gasbarre, L.C., Van Tassell, C.P. 2010. Whole genome association analysis identifies susceptibility alleles for parasitic infection in Bos taurus cattle. International Symposium on Animal Genomics for Animal Health.
Technical Abstract: DNA markers associated with parasite indicator traits are ideal targets for study of marker assisted selection aimed at controlling infections that reduced herd use of anthelminthics. For this study, we collected fecal egg count (FEC) data from post-weaning animals of an Angus resource population challenged to a 26 week natural exposure on pasture. In all, data from 410 animals was collected over a 12 year period between 1992 and 2003. Likewise, DNA samples for genetic analysis were collected and complemented with another 201 DNA samples from animals in the founding pedigree. To normalize phenotype distribution and optimize QTL detection, FEC data was processed using an extension of the Box-Cox transformation. BovineSNP50 genotypes from 611 animals were generated for genome-wide association study (GWAS) analysis, and a total of 26,158 informative markers were used after exclusion of SNP with a low call rate (<98%), minor allele frequency (<5%), and departure from Hardy-Weinberg equilibrium (exact test p<0.01). Empirical p-values were corrected for genome-wide testing and maximization across genetic models. Genome-wide significance level of 0.05 (two-sided) and Bonferroni corrected level of 0.01 were used as thresholds for adjusted significance. The five most significant SNP in this study were detected on chromosome 6 within a linkage disequilibrium (LD) block containing ubiquitin-conjugating enzyme E2K gene. This positional candidate gene is known to have critical role in the function of the adaptive immune system. These findings provide the first evidence of biomarkers for early disease detection in cattle and suggest new molecular targets for disease-modifying therapies that identify animals most likely to benefit from individualized treatment. Supported by USDA ARS CRIS Project No. 1265-31000-098-00D and Merial, Inc.