Tuesday 20 November 2018

Revealed: The secret speed gene that sets thoroughbreds apart

UCD Professor Emmeline Hill
UCD Professor Emmeline Hill
Sean O'Grady

Sean O'Grady

The secret behind why some thoroughbred horses are better equipped to race in sprint distances, and others in long distances, has been unlocked by Irish scientists.

They discovered a protein known as myostatin, which determines muscle growth, is crucial to determining whether horses will be better suited to sprinting or long-distance races.

Scientists from both Trinity College and UCD have been involved in researching the phenomenon.

UCD Professor Emmeline Hill demonstrated that different versions of the myostatin gene almost singularly account for gene-based race distance aptitude in racehorses. This earlier discovery earned the myostatin gene the moniker of "speed gene", with horses with 'CC' copies tending to develop into sprinters; those with 'CT' copies tending to develop into middle-distance performers; and those with 'TT' copies tending to be best equipped for long distances.

In a new study, the scientists pinpointed the specific non-coding section of the 'speed gene'.

This is exclusively responsible for limiting myostatin protein production in thoroughbreds which, in turn, affects skeletal muscle development and race distance aptitude.

The findings have just been published in leading international journal 'PLOS One'.

Associate Professor in Biochemistry at Trinity College Dublin Richard Porter described myostatin production as a "key genetic factor" in determining a thoroughbred's distance aptitude.

"Myostatin is a protein but it's also a hormone. There's a clue in the name. 'Myo' is muscle and 'statin' is stop. It's a hormone produced by muscle to stop muscle growth, if you can believe that," he told the Irish Independent.

"The variation in this gene is the most prominent determent of race distance in horses. It's a major determent.

"There was a mutation, but nobody knew what the mutation did. That was 10 years ago. We worked out in my lab what's wrong and the answer is the sprint horses produce less myostatin compared to endurance horses.

"Because they produce less, they have bulkier muscle and more 'sprint' muscle."

Dr Porter believes the 'speed gene' will ultimately be accepted by the horseracing industry.

"Horseracing in general can be a bit reluctant to embrace science," he said.

"There was a genetic test out there and we have endorsed and enhanced that.

"This test tells you whether you have a large or small amount of this protein. We are pin-pointing to a specific protein and the abundance of it."

Dr Porter believes the discovery will lead to greater efficiency for owners and buyers of horses as they will be able to discern what sort of racing they are better suited to.

"If you're buying a horse, you could test it to know if it's likely to be a sprinter or an endurance horse," he said.

Speaking on RTÉ Radio One's 'News at One', the academic said it was possible that the same sort of testing could be done on humans one day in races, to ensure fairness.

The research was funded by a Science Foundation Ireland Principal Investigator grant awarded to Professor Emmeline Hill while Dr Porter served as a collaborator.

Irish Independent

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