In this issue of the Equine Disease Quarterly, Emma Adam, BVetMed, MRCVS, Dipl. ACVIM, ACVS, PhD, discusses the new genomics tools available to study horse diseases (Editor’s Note: Read Adam’s article at TheHorse.com/38273). Her authorship of this article is particularly noteworthy since Emma initially trained as a veterinary surgeon before returning to university to complete a PhD studying joint diseases in horses. In doing so, she discovered that genomic tools were an effective way to address problems that were not resolvable using earlier technologies.

Her article presents the “nuts and bolts” of horse genomics. As a point of reference, in 1990 we had only characterized 50-100 genes for the horse and confirmed the chromosome location for a mere seven of them. Fast forward to 2009, and the whole genome sequence for the horse had been determined. The immediate application of the sequence data at the time was to identify DNA mutations responsible for well-known diseases of the horse. However, that was only the beginning.

There was a drive to find out how genes function. Everything that we do to a horse turns genes on or turns them off. If genes are defective, it can result in development of disease. Genes are also important for performance. Some genes have variants that affect such things as type of gait, optimal racing distance to reach performance potential, and behavior. Many genes interact with management practices such that horses might be more reactive or, alternatively, less responsive to certain feeding programs, training regimens, or vaccinations. Breeders and trainers attempt to optimize management. These observations clearly suggest that genomics information has a place both in veterinary practice and in the stable yard.

Emma also has been among the scientists developing tools to investigate genes, their expression, and their impact on horses. Before genomics, we basically fed, trained, or treated horses then observed them to assess what the clinical or phenotypic effects might be. Emma’s studies pioneered another approach. Her studies entailed comparing gene expression in joints and other collagenous tissues at different stages of life, including several stages of embryonic development, and then assessing which genes had an impact on healthy growth of that tissue. Understanding the genes that contribute to tissue development and repair should lead to development of veterinary therapeutics that benefit the health and welfare of the horse and rider