Abstract
The Arabian horse breed is well known for its purity and played a key role in the genetic improvement of other horses worldwide. The mitochondrial genome plays a vital role in maternal inheritance and it's helpful to evaluate its genetic diversity and conservation. It has higher mutation rates than nuclear DNA in vertebrates and therefore reveals phylogenetic relationships and haplotypes. In this study, the mitochondrial genome mutations in two Saudi horse strains, Kehilan and Hamdani demonstrated various changes in the gene and amino acid levels and included two other Saudi horses (Hadban and Seglawi) from the previous study for phylogenetic comparison. The whole mitochondrial genome sequencing resulted in intra and inter mtDNA variations between the studied horses. Interestingly, the Hamdani horse has nucleotide substitutions similar to those of the Hadban horse, which is reflected in the phylogenetic tree as a significantly close relationship. This type of study provides a better understanding of mitogenome structure and conservation of livestock species genetic data.