Recurrent Airway Obstruction and eQTLs in Horses

Recurrent airway obstruction (RAO) is a debilitating, performance limiting, obstructive respiratory condition in horses that is phenotypically similar to human asthma, and is triggered by environmental antigens such as organic dust molecules found in hay. Previous studies have reported thousands of genes in horses to be differentially expressed between case and control groups in peripheral blood mononuclear cells (PBMCs) subjected to various treatments. Here we expand upon this by searching genome wide for correlations between genotypes and gene expression changes, i.e. expression quantitative trait loci (eQTLs), as well as eQTLs with batch effect differences between case and control groups. We analyze PBMCs from 40 control and 43 case horses from two half-sib families and one unrelated cohort that were stimulated in four conditions: no stimulation (Mock), lipopolysaccharides (LPS), recombinant cyathostomin antigen (RCA), and hay-dust extract (HDE). Using genotype data from the horse 670k SNP chip and RNA-seq gene-expression data from all treated PBMCs we identified thousands of genes with significant eQTLs, a high proportion of eQTLs shared across treatments, and we are currently looking for eQTLs that differ between case and control groups.