Humans Contributed to the Spread of Genetic Mutation in Horses

A genetic mutation in horses that causes them to move with a gait that humans find desirable was spread to horses around the world by humans, according to new research in the journal Animal Genetics.

A horse's gait is central to its importance to humans, and few animals have played a role so central to human civilization as the horse.

The mutation responsible for a horses gait is technically known as DMRT3 but more affectionately known known as "the gait keeper."

"All over the world, horses have been used for everyday transportation, in military settings, cattle herding and agricultural power, pulling carriages and carts, pleasure riding or racing," said study leader Leif Andersson from the Swedish University of Agricultural Sciences. "Over the centuries, horse populations and breeds have been shaped by humans based on the different purposes for which the animals were used."

The gait keeper mutation controls a range of gaits as well as pace in horses. A smooth gait is a very desirable trait for a riding or racing horse to possess, and many species have been encouraged to breed on account of their smooth gait.

"Humans have spread this mutation across the world primarily because horses carrying this mutation are able to provide a very smooth ride, in some breeds referred to as a running walk," Andersson said. "During such ambling gaits the horse has at least one foot on the ground that means that the vertical movement of the rider is minimal."

Of the 4,296 horses across 141 breeds that Andersson and his colleagues analyzed, the gait keeper mutation was in each of them. The sampling of horses came from all over the world

"For example, the Paso Fino is a breed from Latin America in which the frequency of the 'gait keeper' mutation is nearly 100 percent," Andersson said. "It is claimed that the Paso Fino gait is so smooth that you can have a glass of wine in your hand without letting it spill."