A novel simple genotyping assay for detection of the ‘Gait keeper’ mutation in DMRT3 and allele frequencies in Azteca and Costa Rican Saddle Horse breeds.

This research explores a new method to detect the ‘Gait keeper’ mutation in horses, a mutation known to alter their locomotion, and applies this technique to Azteca and Costa Rican Saddle Horses.

Background of the Research

• The research centers around a particular mutation in the DMRT3 gene in horses, colloquially known as the ‘Gait keeper’ mutation. This mutation, represented as a change from C (cytosine) to A (adenine) in the genetic code, has been found to alter locomotion and gait patterns in horses.
• This mutation has been observed in all gaited breeds of horses analyzed thus far but is not usually seen in non-gaited breeds.

The New Detection Method

• In this study, the researchers developed a new method based on mutagenically separated polymerase chain reaction (MS-PCR) for easily detecting the horse’s DMRT3 genotype. The MS-PCR is a method commonly used in genetic research to produce enough copies of specific DNA sequences for further analysis.
• This methodology offers a simple way to detect the presence or absence of the ‘Gait keeper’ mutation in horses.

Application of the Detection Method

• As a practical application of this new genotyping assay, it was used to determine DMRT3 allele frequencies in two horse breeds: 78 Azteca horses (AZ) and 53 Costa Rican Saddle Horses (CRSH).
• In Azteca horses, a wild-type C allele frequency of 100% was found, meaning no ‘Gait keeper’ mutation was detected in this breed.
• Meanwhile, in the Costa Rican Saddle Horses, the wild-type C frequency was 88.7%, and a mutant A allele frequency of 11.3% was found. This shows that the ‘Gait keeper’ mutation was present in a small percentage of this breed, suggesting that some members of this breed might show altered gait patterns due to the mutation.

Significance of the Research

• This research provides a significant contribution to equine genetics, allowing researchers to easily detect a specific gene mutation associated with distinct physiological traits in horses.
• Having a reliable and simple genotyping technique could facilitate future research investigating the relationship between genetic factors and various traits in horses. It also aids in better understanding and tracking the genetic diversity of horse breeds.