Tracing roots: A study on phylogenetic and genetic diversity in indigenous sheep breeds of Southwestern Türkiye

This study aimed to elucidate the genetic diversity and population structures of indigenous sheep breeds in the southwestern region of Türkiye, thereby addressing the existing gap in molecular genetic information for these breeds. The animal materials used in the study were selected based on the sampling criteria established by the FAO (2011). It included a total of 331 sheep, comprising Dağlıç (48), Eşme (80), Pırlak (29), Pırıt (103), Sakız (37), and Kıvırcık (37), breeds, raised in 6 different provinces of Western Anatolia. A comprehensive analysis of 18 microsatellite loci revealed a diverse range, detecting a total of 493 alleles in the study. The average allele number (Na), effective allele number (Ne), observed heterozygosity (Ho), expected heterozygosity (He), polymorphic information content (PIC), and F_IS values were 27.39, 9.54, 0.70, 0.88, 0.87, and 0.158, respectively. In this study, F_ST and G_ST analyses indicate that genetic diversity is predominantly distributed within breeds, whereas genetic differences between populations are minimal. Indeed, the G_ST value indicated that only 6.1 % of the total genetic variation was attributable to differences between populations. Hardy-Weinberg Equilibrium (HWE) analyses suggest that genetic balance has been disrupted in all populations due to intense artificial selection pressures. These deviations are believed to result from factors such as a lack of random mating, inbreeding, and genetic drift. Especially strong gene flow was detected between the Pırlak-Kıvırcık and Eşme-Pırıt population pairs. The unique alleles of the Pırıt breed highlight its genetically distinct structure. This study offers significant findings for sustainable animal breeding and the conservation of genetic resources. These results serve as a valuable foundation for the genetic management of sheep breeds in Türkiye.