Quantitative analysis of short‐ and long‐distance racing performance in young and adult horses and association analysis with functional candidate genes in Spanish Trotter horses

Abstract

The association of five candidate genes with sporting performance in young and adult Spanish Trotter horses (STHs) was performed according to a previous selection based on quantitative analysis of the trait time per kilometre (TPK). A total of 334 516 records of TPK from 5958 STHs were used to estimate the estimated breeding values (EBVs) at different age groups (young and adults horses) throughout the range of distances (1600-2700 m) using a bicharacter random regression model. The heritability estimated by distance ranged from 0.16 to 0.40, with a different range for the two age groups. Considering the animals with the best and the worst deregressed EBV, 321 STHs were selected for SNP genotyping in MSTN, COX4I2, PDK4, DMRT3 and CKM genes. An association analysis based on ridge and logistic regression revealed that the young trotters with genotype GG in PDK4 (p < 0.05) and AA of DMRT3 (p < 0.001) SNPs show the best potential in short-distance races, while those carrying the genotype AA in DMRT3 (p < 0.001) and CC in CKM (p < 0.05) genes seem to be the best in long-distance races. Adult trotters with genotype AA in DMRT3 also display greater speed (p < 0.05) and endurance (p < 0.001).

A genome-wide association study for harness racing success in the Norwegian-Swedish coldblooded trotter reveals genes for learning and energy metabolism

“…Follow-up studies were then able to demonstrate that for many harness racing breeds the DMRT3 mutation was associated with racing success (e.g. increased earned prize money) [ 20 , 23 – 26 ]. However, the mutation appears to only account for between 0 and 6.3% of the phenotypic variation in traits widely used to evaluate racing success [ 24 , 26 ].…”

“…However, the mutation appears to only account for between 0 and 6.3% of the phenotypic variation in traits widely used to evaluate racing success [ 24 , 26 ]. Considering that heritability estimates for some of these traits are as high as 0.38, the likelihood of other genes playing a significant role in a harness racing horse’s success is high [ 20 , 23 , 27 – 38 ]. Nevertheless, genome-wide association (GWA) studies with harness racing performance are lacking [ 23 ].…”

Genomic analysis of gaits and racing performance of the French trotter

“…In the Spanish trotter, Rama et al. (2016) found AA to be best for speed in short and long distance races at young and adult age. In these breeds, the frequency of each genotype was rather different; in CBT, the genotype frequency of AA, CA and CC was 9%, 51% and 40%, respectively, whereas it was determined to be 37%, 52% and 11% in Finnhorses and 76%, 21% and 2% in Spanish Trotter.…”

“…However, in other trotter breeds, there is still polymorphism. The frequency of the A allele was determined to be 35% in the Swedish Norwegian Coldblooded Trotter (Fegraeus, Lawrence, et al., 2017), 63% in Finnhorses (Fegraeus et al., 2015) and 87% in the Spanish Trotter (Rama et al., 2016). In the French Trotter (FT), the frequency of allele A was estimated at 76% (Ricard, 2015).…”

Estudo de associação genômica ampla para as diferenças genéticas entre as marchas batida e picada em equinos Mangalarga Marchador

“…As proporções de variância fenotípica explicada pelo DMTR3 foram muito similares, 10,77 e 9,94%, quando testados como uma covariável e como um efeito aleatório, respectivamente (Tabela 5). (FEGRAEUS et al, 2015;JÄDERKVIST et al, 2015b;NEGRO RAMA et al, 2016;RICARD, 2015), que descobriam que alguns genótipos também poderiam estar relacionados a melhor desempenho (AA, FEGRAEUS et al, 2015), trote em liberdade (CC e CA, JÄDERKVIST et al, 2015b) e efeito negativo sobre características de corrida (CC, RICARD, 2015), explicando em torno de 0,30 a 1,67% da variância genética aditiva (NEGRO RAMA et al, 2016).…”