The genetic origin and history of speed in the Thoroughbred racehorse

Analysis of polymorphisms in the equine MSTN gene in Polish populations of horse breeds

“…It also may have impact on body composition traits specially at body weight/ withers height (Tozaki et al, 2011b). The relative high frequency of the C allele in Polish Konik horse (0.302) are in line with hypothesis that Polish Konik horses are direct descendants of wild Tarpan horses whose existence was originally in Eurasian steppe where allele C is present in population of residential horse breeds (Bower et al, 2012). The g.66490010T 4C, located in 3′UTR recently has been detected in the Quarter horse breed (Petersen et al, 2013).…”

“…The g.66493737T 4C polymorphism known to predict optimum distance in Thoroughbred horses has been identified in four breeds (Table 4). Our findings suggest that allele C is absent in studied population of Arabian horses, however further investigation may be taken as allele C is present in Egyptian bloodlines (Bower et al, 2012) which were introduced to polish bloodstock through Egyptian stallions. In other investigated breeds, MAF occurs higher than 0.05: Konik Polski (0.302), Polish Heavy Draft (0.281) and Hucul horses (0.038).…”

The horse as an athlete

“…19 The recent demonstration that genotype, and in particular a single nucleotide polymorphism (SNP) of the myostatin gene, of Thoroughbreds is associated with race performance provides evidence that there remains the capacity to improve further performance through selection. 12 The situation differs somewhat with Standardbreds in which there has been a consistent reduction in race times and pace over recent times. 17,18 This improvement is presumably a result of one or more of strong selection pressure, improved training methods, or improved equipment and racing facilities.…”

“…The C allele was introduced into the Thoroughbred breed by a single female during the foundation of the breed, but was rare before it proliferated in the breed as a result of the success of offspring of Neartic and his son, Northern Dancer. 12 Northern Dancer was the most influential stallion of modern times and the success of his offspring in short to middistance races ensured the propagation of the C allele. 12 Amongst current Thoroughbred horses used for sprint racing (≤1400 m), over 90% are either C/C or C/T genotype with 70% of the alleles being C, indicating the effect of profound selection pressure for sprint racing on the distribution of this allele, and related genotypes, in Thoroughbreds.…”

“…This is best exemplified for Thoroughbred in which the emergence of a single nucleotide polymorphism for the myostatin gene can be clearly traced back to the influence of one or two key stallions. 12 The C/C and C/T polymorphisms of the MSTN gene (which encodes myostatin) are, compared to the T/T polymorphism, associated with superior athletic performance by Thoroughbred horses racing over short S h e t la n d I c e la n d ic M in ia tu re that there is sufficient genetic variation within Thoroughbreds to improve performance. 19 The recent demonstration that genotype, and in particular a single nucleotide polymorphism (SNP) of the myostatin gene, of Thoroughbreds is associated with race performance provides evidence that there remains the capacity to improve further performance through selection.…”