Trinity scientists in collaboration with UCD researchers have discovered the element of the “speed gene” which determines why certain racehorses are best suited to race over sprint distances and others over longer distances, in a paper recently published at scientific journal PLOS One.
The researchers found that it was specifically the non-coding section of the “speed gene” that is responsible for limiting myostatin protein production in thoroughbreds. Myostatin affects skeletal muscle growth and race distance aptitude of the horses.
Thoroughbreds have a high aerobic capacity relative to their skeletal muscle mass due to centuries of genetic selection for speed and stamina. Professor Emmeline Hill of UCD previously showed that the myostatin gene exists in different versions between thoroughbred racehorses and account for gene-based race distance aptitude in the horses. Although non-genetic factors such as training can influence racehorse distance aptitudes, the myostatin gene is a genetic factor which distinguishes thoroughbreds from each other.
Combinations of the myostatin gene, also known as the “speed gene,” can exist in three different forms in horses. In each horse, there are two copies of the gene within which there is a single DNA letter position (either a C/T) found to be influential in the horses ability to run. A horse with two C copies (CC) tends to be a sprinter, a horse with (CT) tends to be a middle-distance runner, and a horse with (TT) tends to be a long distance runner. The effect of a single DNA letter can potentially be deterministic in the capabilities of a horses’ athletic performance. This finding could be used in prediction of race allocation and mate selection in horse breeding.
Professor Richard Porter, associate professor in biochemistry in Trinity and senior author of the journal, said: “Our data provides the first mechanistic evidence as to the specific element of the “speed gene” that acts as the sole protagonist in dictating its expression in the thoroughbred. As a result, this element is the key genetic factor in determining distance aptitude in thoroughbred horses. This knowledge is extremely valuable to thoroughbred breeders and trainers, in what is a multi-billion dollar industry.”
The study was collaborative and involved research scientist Mary Rooney and Professor Vincent Kelly from Trinity, and Prof Emmeline Hill for UCD School of Agriculture and Food Science. It was funded by Science Foundation Ireland.