Did you hear the one about the suave Saddlebred stallion who wanted to impress a herd of mares?

He just ambled on by.

We now know that our suave Saddlebred stallion likely has the “Gait Keeper” gene in his chromosomes.

Recent study results from an international group of researchers indicate that a horse’s ability to have gaits such as ambling and pacing comes down primarily to one particular mutated gene: the so-called Gait Keeper gene.

This Gait Keeper mutation appeared spontaneously in a single ancient domestic horse, ultimately triggering breeding programs to maintain the mutation and develop individual breeds from it, said Leif Andersson, PhD, from Uppsala University and the Swedish University of Agricultural Sciences. The exact time period that the mutation, which occurred in the DMRT3 gene, developed has not been determined, he said.

The researchers’ finding dispels the theory that gaitedness occurred independently in various regions, leading to dozens of gaited/pacing breeds throughout the world, Andersson said. “We can see this because we find exactly the same mutation in the same sequence context in all gaited horses we have tested,” he told The Horse.

In essence, humans probably found the new gaits pleasing and decided to selectively breed for the mutation in certain groups of horses, thereby creating “gaited” breeds, he said. Other genes besides the DMRT3 mutation can contribute to gaitedness, “but no other gene variant than the Gait Keeper mutation has been identified with such a strong effect on the gait,” he added.

In their study, Andersson