The “gait keeper” mutation does not influence gait scores in Pêga donkeys: a preliminary result.

Overview

• This study investigated whether the DMRT3 “gait keeper” gene mutation, known to affect horse locomotion, influences gait in Pêga donkeys, a breed selected for gaited movements.
• Results showed the mutation was absent in the donkeys studied, indicating it likely does not impact their gait performance unlike in horses.

Background

• The DMRT3 gene mutation, specifically the A allele at exon 2, is well-known to influence gait patterns in horses, particularly enabling smooth, specialized gaits.
• In horses, this mutation is common in gaited breeds and strongly associated with differences in locomotion styles such as pacing and ambling.
• Donkeys, particularly the Pêga breed, are also selected for gaited locomotion, but it is unclear whether the same mutation plays a role in their gait differences.

Research Objective

• The primary aim was to assess if the DMRT3 mutation (allele A) is present in Pêga donkeys and whether it correlates with their gait performance.
• Researchers wanted to understand if the genetic basis for gaited locomotion in donkeys overlaps with that known in horses.

Methods

• A total of 260 Pêga donkeys were analyzed.
• Each donkey was phenotyped for gait scores – a quantitative measure of gait quality/performance.
• Genotyping for the DMRT3 gene focused on exon 2 was performed via PCR-sequencing to detect the presence of the mutant A allele or wild-type C allele.

Findings

• All 260 donkeys were homozygous for the wild-type allele (CC), meaning none carried the gait-related mutant (A) allele.
• Because of this homozygosity and lack of variation in the DMRT3 gene among the sample, no association could be found between this gene and gait scores.
• This suggests the DMRT3 “gait keeper” mutation does not influence gait characteristics in Pêga donkeys.

Interpretation

• The absence of the A allele in a gaited donkey breed contrasts strongly with its frequent occurrence in gaited horse breeds, indicating species-specific genetic differences.
• The results imply the genetic architecture underlying gait adaptation in donkeys might be driven by different genes or mutations than in horses.
• This may reflect evolutionary divergence in locomotion traits between horses and donkeys despite superficial gait similarities.
• The “gait keeper” mutation’s known functional role in horses does not seem to extend to Pêga donkeys, pointing to other genetic pathways contributing to gaited locomotion in donkeys.

Conclusions and Future Directions

• The study provides preliminary evidence that the DMRT3 mutation is not a determinant of gait in Pêga donkeys.
• Future research should explore alternative genetic factors that influence gait in donkeys, possibly through broader genome-wide association studies (GWAS) or candidate gene approaches.
• Larger and more diverse donkey populations could be studied to confirm these findings and further elucidate the genetic basis of gait evolution in equids.