The DMRT3 ‘Gait keeper’ mutation affects performance of Nordic and Standardbred trotters.

This study expands on previous findings on the influence of the DMRT3 gene mutation on horse locomotion, particularly in trotting behaviours. The research also deliberates on the potential impact of the gene mutation on the trotting performance of both Nordic and Standardbred horses.

Objective and Methodology

• The primary aim of the study was to understand if the DMRT3 gene affects the trotting performance and technique in Nordic trotters.
• The research also sought to further clarify the impact of the DMRT3 gene mutation on the performance of Standardbred horses.
• The investigation encompassed genotyping a total of 427 Nordic trotters and 621 Standardbred horses to identify the DMRT3 nonsense mutation and a SNP (Single Nucleotide Polymorphism) in strong linkage disequilibrium with it.

Findings: Nordic Trotters

• The analysis revealed that Nordic trotter horses with the DMRT3 mutation (A) showed significantly superior performance traits in trotting than heterozygous (CA) or homozygous wild-type (CC) horses.
• Furthermore, AA homozygotes had a higher proportion of victories and secured top 3 placings more frequently when compared to horses heterozygous or homozygous wild-type in performance data collected for the periods corresponding to 3 to 6 years of age.
• The DMRT3 mutation was observed to have a strong influence on the trotting technique in Nordic trotters.

Findings: Standardbred Horses

• Standardbred horses displaying the homozygous AA DMRT3 mutation were found to have significantly higher performance traits across all categories when compared to horses with at least one wild-type allele (CA and CC).
• A within-family analysis of Standardbreds revealed remarkable differences in several traits among paternal half-sibs with genotype AA or CA fathered by a CA stallion. These differences included earnings, the number of races entered, and the fraction of offspring that entered races.
• Significant differences were found in most traits at young ages (ages 3 to 5), showing that the mutation impacts performance at earlier ages.

Implications of the Findings

• The findings of this study are crucial as they highlight the significant impact the DMRT3 mutation has on horse locomotion and trotting performance across Nordic and Standardbred trotters.
• The results of the study can have potential implications on breeding strategies and selection processes of trotting horses, aiming for better performance.
• Additionally, understanding the influence of genetic factors such as the DMRT3 mutation can contribute extensively to further research in horse locomotive behaviour and performance, benefiting various racing and equestrian domains.