A new paper out on Nature this week is very interesting and has some wide implications for the harness horse and also humans. Lead by a group of Swedish scientists, they have identified a genetic variant that influences gait in vertebrates, which has significant implications for breeders of trotting horses and may also lead to greater understanding of human paralysis.
The report , which appeared in the journal Nature and can be found here, closely studied the Icelandic Horse, a breed that famously likes to pace and is noted for its smooth stride. Building on earlier work on lab mice, a team led by Leif Andersson at Uppsala University and the Swedish University of Agricultural Sciences compared the genetic code of 70 horses - 40 that could pace and 30 that could not.They discovered that there was a variation in a key gene known as DMRT3 in the 40 pacing horses. DMRT3, which is in humans also, controls a protein in nerve cells in the spinal cord that the researchers believe is crucial in the coordination of leg movements in vertebrates. Interestingly the genetic variation, which has obviously been selected upon for some time, was found not only in pacers but also trotters which may indicate that that the variation has further function in other breeds as a negative variant. That is, the presence of the variation in say a thoroughbred, might mean that it is a slow horse.