The international Equine Consortium for Genetic Research (ECGR), established by Morris Animal Foundation (MAF), has made major inroads into determining the location of genes that cause specific disease traits in horses. The ECGR is a worldwide research project led by University of Minnesota equine professors Drs. Jim Mickelson and Stephanie Valberg, with 32 scientists from 18 elite academic institutions throughout the nine countries collaborating.
With MAF funding, members of the ECGR are using SNP (single nucleotide polymorphism) chips—a genetic tool recently developed with funding from MAF, the U.S. Department of Agriculture (USDA) and European partners—to study recurrent exertional rhabdomyolysis, commonly known as tying-up, in Thoroughbreds; lavender foal syndrome in Arabians; extreme lordosis, or swaying of the back, in saddlebreds; dwarfism in miniature horses as well as susceptibility to cribbing and immune/infectious diseases in a number of breeds. In several cases, they are close to identifying the location of the genetic mutation(s) responsible for a particular disease.
“The SNP chips allow us to identify those genes that contribute to a genetic disease much more quickly,” Dr. Mickelson explained. “We can then hope to more rapidly find the specific gene and mutation and develop a DNA test to determine a horse’s genetic risk for susceptibility to that particular disease.”
For more complicated diseases, researchers use whole genome gene expression microarrays to look at a host of diseases that may involve hundreds and even thousands of genes in the disease process. Scientists are poised to start individual projects to study laminitis, recurrent airway obstruction (RAO), cartilage maturation and repair, response to glucocorticoid therapies, allergic skin diseases and normal placental development.
Based on the consortium’s initial success, the University of Minnesota group recently received a $550,000 grant from the USDA to study genetic bases for metabolic syndrome, which may predispose horses to a particular form of laminitis. The group will also develop online tools to provide information to the equine industry and help them get involved in research. MAF committed additional funds to other ECGR members to facilitate their own equine genetic disease research efforts. MAF funding is also providing valuable funding to train graduate students in genetic research.
Future SNP chip projects hope to focus on genetic factors associated with osteochondrosis dessicans (OCD), RAO and pasture-associated laminitis.