Identification of the myostatin locus (MSTN) as having a major effect on optimum racing distance in the Thoroughbred horse in the USA.

The research studied the link between genetic factors and the optimal racing distance in thoroughbred horses in the USA. The study found that the myostatin gene (MSTN) plays a significant role in determining these distances.

Methodology

• The study involved the genotyping of 189 thoroughbred horses that had won Graded Stakes races in North America, using the Illumina Equine SNP50 bead chip.
• Association tests were performed to investigate if any SNPs (Single Nucleotide Polymorphisms, a kind of genetic variation) could be associated with the optimum racing distance (7 furlongs and under as compared to 8-10 furlongs).
• The researchers utilized a software called PLINK for the association tests and for data analysis.

Results

• The study found a genetic locus on ECA18 that was statistically significant at the genome-wide level. The researchers found this by performing permutation analysis with 10,000 permutations (iterative reorganization of the testing data).
• The statistical significance of the ECA18 SNPs suggests that the MSTN locus is likely the significant factor influencing the observed effect.

Linking MSTN to Racing Distances

• Mutations in the MSTN gene in many mammalian species have been reported to be connected with increased muscling, particularly in fast glycolytic type IIB fibres which increase power potential.
• Thoroughbred horses that race over sprint distances (5-7 furlongs) often have impressive hind quarter musculature.
• Therefore, it is strongly suggested that the association observed between the ECA18 SNPs and optimum race distance is mediated through the MSTN gene.

Conclusion

• Thus, the research article concludes that the myostatin locus (MSTN) has a major effect on the optimum racing distance of thoroughbred horses in the USA.”