Genomic assessment of stress in the horse

Thanks to the sequencing of the equine genome in 2009, it is now possible to perform genomic analyses in the horse. Thus, we propose to assess chronic stress by a transcriptomic approach. Two groups of yearlings were maintained in impoverished (n=9) or enriched (n=10) social and sensory conditions. The transcriptomic analysis was performed in blood cells after 12 weeks of experimentation. Results were analyzed with the program TELiS in order to identify the biological pathways differentiating the 2 groups. The analysis showed an up-regulation of the factors CREB, ATF and GATA in impoverished conditions that could sign the distress of those animals since the same molecular pathway has been detected in socio-environmental adversity in humans. This transcriptomic analysis provides a biological signature of yearling welfare that completes the behavioral analyses and help to evaluate disease risk. Gene expression induced by environmental conditions in horse blood was measured after 12 weeks of experimentation. There were 9 samples for the impoverished conditions and 10 samples for the enriched conditions.