eQTL Discovery and their Association with Severe Equine Asthma in European Warmblood Horses

Severe equine asthma, also known as recurrent airway obstruction (RAO), is a debilitating, performance limiting, obstructive respiratory condition in horses that is phenotypically similar to human asthma. We searched genome wide   for associations between genotypes and additive changes in gene expression, i.e. expression quantitative trait loci (eQTLs). We analyzed peripheral blood mononuclear cells (PBMCs) from two half-sib families and one unrelated cohort that were stimulated in four conditions: no stimulation (MCK), lipopolysaccharides (LPS), recombinant cyathostomin antigen (RCA), and hay-dust extract (HDE). We identified high confidence eQTLs that do not violate linear modeling assumptions and are not due to single outlier individuals that heavily influence significance. On average, we identified 4347 high confidence eQTLs in four treatments of PBMCs, discover two trans regulatory hotspots regulating genes involved in related biological pathways, and identify SNPs strongly linked with previously RAO associated disease SNPs that regulate gene expression of dexamethasone-induced protein (DEXI).