Posters CHARACTERIZATION OF A HUMAN PERFORMANCE GENE IN THE HORSE

Although estimates of heritability of performance in the Thoroughbred racehorse have been calculated to be between 10-40%, no genes influencing performance have been identified. Based on comparative studies with human, we identified the angiotensin-converting enzyme (ACE) gene as an equine candidate gene for performance. From characterization of nine SNPs, nine equine ACE haplotypes were identified in 34 horses. The haplotypes occurred at differing frequencies in breeds of different athletic capabilities, including endurance Arabians, Thoroughbred racehorses and Draught horses. One haplotype had a similar effect on equine ACE levels as the recognised Alu insertion/deletion polymorphism in the human gene. Further studies are suggested to test the association of this haplotype with a range of indices of performance in substantially larger cohorts of horses before these markers can be used for prediction of racing performance.