Can DNA predict Speed or Stamina in a Racehorse?
by John Tuckfield | April 4, 2011
Larry Greetham of Piplyn Lodge has drawn my attention to a fascinating piece of
research out of University College, Dublin. The paper is entitled A Sequence
Polymorphism in MSTN Predicts Sprinting Ability and Racing Stamina in
Thoroughbred Horses by Emmeline W. Hill et al and can be easily found by googling
the title. It is also written up in the July edition of Equus.
My scientific knowledge is such that I need an abstract of the abstract, but as I
understand it the research has resulted in the development of a test that can identify
which version of the myostatin gene (MSTN) a particular horse has. Myostatin is a
protein that regulates muscle growth and development.
DNA can be thought of as being made up of the letters G, A, T and C. The various
combinations of those letters spell out a horse's unique genetic code. In the myostatin
gene, a single change from a C to a T can lead to dramatic differences in when and how
a horse's muscle mass develops. Because one copy of the variant is inherited from the
sire and one from the dam an individual will be either C:C,
C:T or T:T. By comparing the racing performances at different distances of 179 Group
race winning racehorses to individual MSTN geno-types, the researchers were able to
identify relationships between genetics and success over various distances.
Horses with two copies of the 'C' variant of the gene, C:C, typically have greater muscle
mass as 2-year-olds and excel in sprint races up to one mile in length. In contrast,
horses with the T:T variant are best suited to races longer than one mile and generally
do not perform optimally as 2-year-olds. This doesn't mean they won't mature into great
horses; just that they take longer to mature The final MSTN variant identified is C:T, a
mixture of speed and stamina, indicates the horse is equally likely to win at both shorter
and longer distances.
The test cannot predict which horses will be winners; instead it simply suggests which
race distances best suit them. You could enter a C:C horse in a 2yo sprint only to find
that he's still slower than the rest of the field. The real benefit of this test is that it allows
the horses to be treated as individuals and managed in the optimum manner.
Identifying the MSTN variation that a particular horse carries can help guide key training
and racing decisions. If you know a horse is a T:T, you might choose to minimize racing
during his 2-year-old year to let him mature, then enter him in longer races as a mature
horse to maximize his chance of success.
Also, because a horse's MSTN variation is genetically inherited from both his parents, a
breeder can match mares and stallions based on the desired outcome. For example, If
you have a mare that is a C:T and you'd like to get a sprinter out of her, you'll have the
best chances of getting one if you match her with a stallion that is a C:C.
Following the success of the research programme, Dr Hill and Jim Bolger, the renowned
Irish racehorse trainer and breeder, co-founded a new biotech company, Equinome
(that has a very informative web site that includes some talks on the subject by Dr Hill) in
2009 to commercialise the test.
A blood sample is needed for the gene test, which costs approximately US $1,250.
