Equinome Speed Gene Test – A New Genetic Tool for Trainers / National / 03 Feb, 2011

Founded in 2009 by Dr Emmeline Hill, a leading horse genomics researcher at University College Dublin (UCD), Ireland, in partnership with Mr. Jim Bolger, the renowned Irish racehorse trainer and breeder, Equinome came to prominence in January 2010 when Dr Hill and her colleagues published the results of a six year study into the genomics of performance of the Thoroughbred.

The study identified a variant in a gene related to muscle-mass development that is predictive of an individual horse’s optimum racing distance, a breakthrough which has the potential to transform decision-making processes in the horseracing industry.

This report was the first known characterization of a gene related to a specific athletic trait in the Thoroughbred, and the findings were published in January 2010 in the peer-reviewed scientific journal, PLoS One.

The Equinome researchers identified that at a specific point in the myostatin (MSTN) gene the genetic code can be spelt with either a ‘C’ or a ‘T’. Each horse has two copies of the gene – one inherited from the dam and one from the sire – which means that there are three potential genetic types (genotypes): C:C, C:T and T:T.

> A C:C genotype horse is typically an early-maturing, sprint type which is optimally suited to distances of 1000m-1200m, with a limit of 1600m

> A C:T genotype horse tends to be more versatile, with a balance of speed and stamina, and is best suited to distances of 1400m-2400m

> T:Tgenotype horse tends to be later-maturing and with enhanced stamina, and performs optimally over distances of 2000m plus

It is not possible to definitively determine which genotype an individual horse is – and therefore its likely optimum racing distance – through an analysis of its pedigree. Similar to the likelihood of producing either a filly or a colt, mating a C:T mare with a C:C stallion is equally likely to produce either a C:C or C:T foal. In the same way, the progeny of a C:T / T:T mating are equally likely to be C:T or T:T.

Most interestingly, the likely outcomes of a C:T / C:T mating are 25% C:C, 50% C:T and 25% T:T, which historically has often been observed in full siblings who turn out to be ideally suited to racing over entirely different distances.

Analysing the specific genetic makeup of an individual is therefore the only way to know with certainty which of the three categories they fall into. The exceptions to this are putting a C:C mare to a C:C stallion, which will ensure that a C:C foal is produced 100% of the time, and similarly for a T:T mare and T:T stallion. A C:C mare mated with a T:T stallion (or vice versa) will also always produce a C:T foal. But in these instances, the genotype of both parents must be known.

Critically, the study also investigated the relationship between the three genetic types and potential earnings as two-year-olds. Examining 142 two-year-olds in training with the same trainer, it was found that the C:C and C:T genotypes were more successful than the T:T types for all parameters of racing success and earned on average over five times more than T:Ts during their two-year-old season. This is a reflection of the limitation of race distances for two-year-olds and the relative precociousness of the different genotypes.

Racehorse owners and trainers can now use this developed technology to optimise their purchasing and training decisions, enabling them to select with more certainty the type of horse that they wish to race, to better target suitable races for horses at the early stages of their careers and to increase the returns on their investment.

Equinome also has an ongoing, comprehensive research programme using the latest genomics technologies to continue to identify and characterise the molecular genetic variants underlying key performance and health traits in the Thoroughbred. It is expected that further research opportunities provided through newly available technologies developed since the sequencing of the horse genome will lead to the commercialisation of additional genetic tests.

Australian clients who wish to avail of the Equinome Speed Gene Test must provide a 4-5ml uncoagulated blood sample for each horse, download a copy of the Sample Submission Form and VET15 Import Licence from the Equinome website (www.equinome.com) and then contact the company office to arrange for courier collection and shipping of the samples to the Equinome laboratories. Results will be returned within seven days of receipt of the blood samples.

To contact Equinome directly, please email info@equinome.com or telephone Equinome’s offices on +353 1716 3775.