A sequence polymorphism in MSTN predicts sprinting ability and racing stamina in thoroughbred horses.
Authors: Hill Emmeline W, Gu Jingjing, Eivers Suzanne S, Fonseca Rita G, McGivney Beatrice A, Govindarajan Preethi, Orr Nick, Katz Lisa M, MacHugh David E
Journal: PloS one
Summary
# Editorial Summary: MSTN Polymorphism and Racing Distance Aptitude in Thoroughbreds Myostatin (MSTN) variants influence muscle development across numerous mammalian species, yet their role in equine athletic performance had remained largely unexplored until Hill and colleagues identified a specific sequence polymorphism (C>T at position 66493737) that correlates significantly with optimal racing distance in elite Thoroughbreds. The research team genotyped 148 registered horses, then validated findings in two independent cohorts (62 and 37 animals respectively), establishing a robust association between genotype and competitive distance profile: homozygous C/C horses excel at sprint distances, heterozygous C/T animals perform optimally at middle distances, whilst homozygous T/T individuals possess greater stamina for extended races. Notably, C/C and C/T genotypes predicted earlier racing success as two-year-olds, suggesting this variant influences not only distance preference but developmental trajectory. This polymorphism represents the first genetically validated marker for athletic phenotype in Thoroughbreds and offers trainers, stud managers and selection programmes a molecular tool to align young horses with appropriate race profiles, potentially reducing injury risk from mismatched distance demands whilst optimising both performance and longevity within a competitive career.
Read the full abstract on PubMed
Practical Takeaways
- •MSTN genotyping can inform early identification of racing potential and optimal race distance for Thoroughbred prospects, improving training and race selection decisions
- •T/T horses should be targeted for longer-distance races where their stamina advantage becomes apparent, while C/C horses are better suited to sprint programs
- •Two-year-old race success is genotype-dependent; C/C and C/T animals may have earlier competitive advantage, while T/T animals develop later with distance
Key Findings
- •A novel MSTN gene polymorphism (g.66493737C>T) is strongly associated with best race distance in Thoroughbreds (P = 4.85×10⁻⁸ in initial cohort, n=79)
- •C/C genotype predicts suitability for short-distance sprints, C/T for middle-distance, and T/T for stamina-dependent longer races
- •C/C and C/T genotypes are more likely to succeed as two-year-old racehorses compared to T/T horses
- •Findings were independently validated in two separate Thoroughbred cohorts (P = 1.91×10⁻⁶ and P = 0.0047)