Investigating the Origin and Genetic Relationships of Iranian, Akhal-Teke and Arabian Horse Breeds Through Mitochondrial Genome Analysis

Subject Areas :

E. Rezvannejad ¹ , K. Nobari ² , M. Asnaashari ³ , S. Ghazanfari ⁴

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Received: 2025-01-19 Accepted : 2025-02-28 Published : 2025-03-01

Keywords: genetic diversity, horse breeds, mitochondrial genome, phylogenetic,

Abstract :

Throughout human civilization, horses have played significant roles in social, cultural, economic, and sport-ing dimensions. Even today, horses play an important role in human life, particularly in recreational and sporting activities. Understanding the relationships between breeds and genetic diversity can guide the de-sign of necessary strategies to utilize the potential of this noble species. The mitochondrial genome, which is inherited exclusively from the mother to offspring, is widely used for phylogenetic studies. Given the geographical and social proximity of Iran to countries with Arab and Akhal-Teke breeds, the genetic rela-tionship between these breeds and Iranian horses has been investigated in the context of the presence of other breeds worldwide. Therefore, the mitochondrial genome of 174 horses from 78 breeds worldwide was obtained from the NCBI database, and they were analyzed using the CLC Genomic Workbench 23.0.5 software and various packages of the R software. Alignment and phylogenetic tree construction based on the alignment and the Maximum Likelihood method were performed and compared. Finally, the haplotypes resulting from the genomic regions under investigation were examined. In terms of intra-breed diversity, Arab, Iranian, and Akhal-Teke horses ranked highest. The method of phylogenetic tree construction had a significant impact on shape of the resulting tree. Regarding the number of unique haplotypes in the D-loop and CYTB regions, Iranian horses had the highest number of haplotypes and showed closer affinity to the Akhal-Teke breed. In the HVR-1 region, Arab horses had the highest number of haplotypes and showed the greatest affinity with the Akhal-Teke breed. The D-loop haplotype network divided the studied population into two groups, while the HVR-1 haplotype network demonstrated that a more precise and less complex differentiation could be achieved based on it. Finally, the results support the close relationship between Arab, Iranian, and Turkmen horses, indicating a common origin among them.

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