Origin of a 'speed gene' in horses

A 'SPEED GENE' in thoroughbred horses can be traced back to a single British mare that lived in the United Kingdom around 300 years ago, according to findings published online this week in Nature Communications. This so-called "speed gene" is a variant of the myostatin gene, which plays a role in muscle development. The makeup of this gene in thoroughbreds can be a predictor of how they are likely to perform over different distances.

The presence of a C or a T at one point in the gene has an influence - C:C horses are best suited to fast, short-distance, sprint races, C:T horses tend to compete well in middle-distance races and T:T horses have greater stamina.

To figure out the origin of the C, the researchers analysed DNA from 22 Eurasian and North American horse breeds, museum specimens from 12 historically important thoroughbred stallions, 330 elite performing modern thoroughbreds, 40 donkeys and two zebras. “We first started looking in the stallions because that’s where we had anticipated finding it. But when we didn’t, we then had to go searching further afield,” senior author of the study Dr Emmeline Hill told The Irish Times.

“The results show that the ‘speed gene’ entered the thoroughbred from a single founder, which was most likely a British mare about 300 years ago when local British horse types were the pre-eminent racing horses, prior to the formal foundation of the thoroughbred racehorse.”

Hill is a genomics scientist at University College Dublin and a co-founder of UCD spin-out Equinome, which has developed a test for the speed gene.

The new analysis also traced modern variants of the original speed gene to the legendary Nearctic (1954–1973), and attribute the wider expansion of these variants to Nearctic’s son Northern Dancer (1961–1990). The international study, which was supported by grants from various agencies including Science Foundation Ireland, involved researchers at UCD, the University of Cambridge, Trinity College Dublin, the Russian Academy of Sciences and the Swedish University of Agricultural Sciences.