Mitochondrial DNA variation reveals shared maternal lineages between Kazakh and Turkish fat-tailed sheep breeds

Local livestock breeds represent a significant genetic resource shaped by historical human migrations. While morphological similarities between Central Asian and Anatolian sheep breeds have long suggested a shared ancestry, molecular evidence linking these populations to specific historical migrations remains limited. This study investigates the genetic diversity and phylogenetic relationships of Kazakh (Edilbay) and Turkish (Akkaraman, Morkaraman, Awassi) fat-tailed sheep breeds using mtDNA D-loop sequencing to explore the maternal lineages of these historically connected populations. The study included Edilbay sheep from Atyrau (Kazakhstan) and Akkaraman (Kırşehir), Morkaraman (Iğdır), and Awassi (Şanlıurfa) sheep from Türkiye. Genomic DNA was extracted using the salt precipitation method. A 531 bp fragment of the mtDNA control region (D-loop) was amplified. Genetic diversity indices were calculated using DnaSP v6, while population structure (AMOVA and pairwise F ST ) was analyzed in ARLEQUIN v3.5, and phylogenetic relationships and haplogroup networks were reconstructed using an unrooted Neighbor-Joining tree in SplitsTree 4 and a Median-Joining network in Network 4.1, respectively. Our results reveal high levels of genetic diversity (Hd: 0.990) in the studied populations, indicating a rich maternal genetic diversity in the region. We found a very low genetic differentiation (F ST = 0.017) and shared haplogroup structure (predominantly Haplogroup B) between the Kazakh Edilbay and Turkish Morkaraman breeds. This genetic affinity reflects historical connections among sheep populations distributed across regions historically linked by pastoral movements and trade routes. In contrast, the Awassi breed formed a genetically distinct and isolated cluster (F ST > 0.30), reflecting distinct maternal lineages rooted in the Fertile Crescent. These findings clarify the maternal genetic structure of these indigenous breeds and support a historical connection, highlighting the Morkaraman and Edilbay as conserved genetic reservoirs of a shared pastoral heritage.