Sequences whole mitochondrion genome of local Arabi sheep in Basrah

Ovis aries is a vital livestock species in Iraq. The Arabi breed plays a significant role in the Iraqi national agricultural production. Despite their importance, genetic studies on Arabi sheep have remained limited. This study aimed to characterize, for the first time, the complete mitochondrial genome of the Arabi sheep breed in Basrah, Iraq. This is essential for understanding the genetic diversity of the species and for improving their productivity and health. The findings will contribute to enhancing food security, reducing veterinary costs, and supporting the Iraqi rural economy. To clarify its genetic diversity and evolutionary relationships, blood samples were collected from 165 Arabian sheep. PCR amplified the mtDNA, which was sequenced and analyzed using DNASTAR SeqMan Ultra, BLAST, and MEGA12 software for genome assembly, mutation identification, and phylogenetic analysis. The complete mtDNA genome was 16,619 base pairs long, aligning closely with the lengths reported in other Ovis aries breeds. Three single-nucleotide variants were identified and deposited in GenBank under accession numbers LC649167, LC649168, and LC649169, showing over 99% similarity to the Hamdani breed; suggesting a close maternal lineage and a possible genetic admixture. The phylogenetic analysis, performed using the Neighbor-Joining method in MEGA12 with 1,000 bootstrap replications, revealed a genetic affinity between Arabi, Hamdani, and Lezgin breeds, which supports a common geographical origin. The mtDNA's slow mutation rate, functional constraints, and human-mediated breeding practices likely contributed to the observed genetic similarity among breeds. The identified mutations in various mitochondrial genes may influence energy metabolism, growth, and adaptation.