Study of Variation of ACOX1 Gene Among Different Horse Breeds Maintained in Iran

The <i>ACOX1</i> gene is vital for fatty acid metabolism and is linked to environmental stress and physical exertion adaptation. The p.Asp237Ser variant (rs782885985) in <i>ACOX1</i> is associated with increased enzyme activity and reactive oxygen species (ROS) levels. This study examined the <i>ACOX1</i> polymorphism across six horse breeds in Iran: Arabian, Thoroughbred, KWPN, Caspian, Kurdish, and Turkmen. The goal was to identify differences in <i>ACOX1</i> genotype distribution, potentially serving as genetic markers under selection pressure related to breed-specific traits. In a sample of 324 horses, genomic DNA was analyzed using PCR-RFLP, revealing three genotypes (TT, TG, GG). The GG genotype was most common in Kurdish and Arabian horses (86% and 70%, respectively), while the TT genotype was prevalent in Turkmen (24%) and Thoroughbred horses (23%). The T allele's frequency in Thoroughbred and Turkmen horses suggests that ACOX1 may be under selection pressure for phenotypic traits. Differences in genotype distribution were confirmed among breeds, with no sex-based association. The study concludes that <i>ACOX1</i> is a potential genetic marker for horse performance and adaptability, emphasizing the importance of genetic diversity in breeding programs.