A research team led by Plusvital’s CSO, Prof Emmeline Hill, have today published a scientific paper that identifies the specific mutation in the Speed Gene that causes the change in muscle growth in the Thoroughbred. This variation in muscle growth and muscle fibre type differentiation manifests itself on the track in terms of the optimum race distance for a horse.
Thoroughbred horses are finely-tuned athletes with a high aerobic capacity relative to skeletal muscle mass, attributable to centuries of genetic selection for speed and stamina. Polymorphisms in the myostatin gene, a pronounced inhibitor of skeletal muscle growth, have been shown to almost singularly account for gene-based race distance aptitude in racehorses, earning the myostatin gene the moniker of “Speed Gene”.[vc_single_image image=”8432″ img_size=”full” alignment=”center”]In Thoroughbreds, two myostatin gene polymorphisms, a single nucleotide variation in the first intron (SNP g.66493737C>T) and a non-coding transposable element within the promoter region (a 227 bp SINE insertion) are of particular interest. Until now, it has not been clear which of these variants affect skeletal muscle phenotypes or whether both can impact racing performance.
In a large cohort of Thoroughbreds, we observed a complete concordance between the SNP and the SINE insertion. We isolated the SNP variant from the SINE polymorphism and showed the latter is exclusively responsible for adversely affecting transcription initiation and gene expression thereby limiting myostatin protein production. Our data provides mechanistic evidence that the SINE insertion is the sole protagonist in modulating “Speed Gene” expression and is therefore a key genetic factor in determining distance aptitude in Thoroughbred horses.
This new research clearly shows that Plusvital’s long-standing and patented Speed Gene Test is a suitable marker for the functional mutation, further reinforcing the scientific credibility of the test. These new results add to the body of evidence produced by Plusvital scientists that show a remarkably strong correlation with results on the racetrack and now show clear causation in terms of the specific genetic effect on muscle growth.