The findings of a study to learn more about the genetic basis of trotting talent among Nordic trotters suggests racing ability includes not only physical prowess but also mental characteristics.
Horses have been strongly selected for speed, strength, and endurance-exercise traits since the onset of domestication.
As a result, highly specialized horse breeds have developed. Many are closed populations with high uniformity in body shape and genetics.
However, a great deal of variation still exists between breeds, making the horse particularly well suited for genetic studies of athleticism.
Brandon Velie and his colleagues set out to sequence data from three Nordic horse populations to identify genomic regions associated with athleticism, in particular trotting racing ability.
Their study used 18 Norwegian-Swedish Coldblooded trotters, 25 North Swedish Draught horses and 22 Standardbred trotters. Genomic DNA samples from these horses were prepared from blood samples and pooled.
Their analysis revealed 580 differentiated regions for trotting racing ability, with candidate regions on equine chromosomes 7 and 11 being a particularly rich source.
“Not unexpected for genomic investigations of complex traits, the current study identified hundreds of candidate regions contributing to trotting racing ability in the horse,” the study team reported in the journal BMC Genomics.
Their analysis identified multiple genes related to intelligence, energy metabolism, and skeletal development as potential candidate genes.
“Likely resulting from the cumulative effects of many variants across the genome, racing ability continues to demonstrate its polygenic nature with candidate regions implicating genes influencing both musculature and neurological development.
“Candidates for trotting racing ability implicated both genes influencing musculature and conformation, as well as genes involved in neurological development, further suggesting that racing ability may not solely be a product of physical characteristics, but also mental characteristics.”
Velie, B.D., Lillie, M., Fegraeus, K.J. et al. BMC Genomics (2019) 20: 104. https://doi.org/10.1186/s12864-019-5484-9