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Scientists find THE PACING GENE

Does that mean that some horses are born to win?

Originally published Summer 2013

Have you ever felt that your horse was made to do his job? It turns out some horses are actually genetically predisposed to succeed in harness racing, a discovery that could change the industry.

Scientists at Sweden’s Uppsala University have recently discovered a single gene that determines a horse’s locomotion, and whether a horse can “pace,” a gait separate from the walk, trot, and canter of the average horse. Pacing is a motion in which both legs on the same side move forward at once, and is a movement that some horses simply cannot achieve. As such, the discovery could prove to have dramatic consequences on the sport of harness racing, where pacing is required, and a break to the gallop results in disqualification.

A Single Gene

The team compared the genetic code of a group of horses, and discovered that there was just a single change in the genetic code of the horses that could pace–a key gene known as DMRT3. In an interview with The New York Times,  the lead researcher, Leif Andersson called it a “sensational finding.”

Andersson and his team began by looking at Icelandic horses, who are known for their comfortable ambling gait, called tölt. From there, they began studying horses with this extra gait, such as the Tennessee Walking Horse and the Paso Fino. It turned out that every horse that demonstrated this extra gait also had this particular genetic mutation. No horses showed the gene without showing the ability to pace. When they began to study the Swedish harness racing horses, the mutation was linked to higher race performance, breeding values, and increased prize earnings over a horse’s career.

In an interview with ScienceOmega.com, Andersson elaborated the importance of the study on our knowledge of the evolution of today’s horse, “The gait of the horse is important to the ways in which we can use it. The driving force behind this would have been that humans thousands of years ago or more noticed there were some horses with a different gait that made riding smoother and easier. That was an advantage in a time when there were no cars and people were spending days and days on horseback. If it produced a smoother ride, that trait would be favored.”

Improving the Odds

Though genetics cannot predict the outcome of a race, it can help owners and breeders of harness racing horses to determine their potential, and can therefore save the money that would need to be invested in years of training the wrong horse. “Training a horse for two years is a costly practice,” Andersson said. “If a horse doesn’t have the best constitution, it’s a waste of your money.” Scientists have already patented a DNA test to identify the DMRT3 variant, allowing horse buyers to know before purchasing whether the horse has the increased likelihood of pacing and therefore success as a harness racer.

The findings also have important implications for human medicine, including treatment for paralysis and spinal cord injuries. The discovery has given the medical community a wealth of new information regarding locomotion, and about how the spinal cord controls the movement of the legs.

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