Genetic Characterization of Kazakh Native Sheep Breeds Using Mitochondrial DNA

Abstract

In this study, we used mitochondrial (mt) DNA to reveal patterns of genetic diversity among six breeds of sheep native to Kazakhstan, including the Chu and Kalchengel types of Kazakh mutton-semifine-wool breed of sheep, Akzhayik, Edilbay, Kazakh fat-rumped semi-course-wool and South Kazakh Merino breeds. Mitochondrial DNA D-loop was studied in 64 samples to determine the genetic diversity of the local sheep breeds. The analysis identified 54 haplotypes and 113 polymorphic loci of mtDNA D-loop. For the studied breeds, haplotype diversity and nucleotide diversity were 0.993±0.005 and 0.039±0.001, respectively. The results indicated higher level of nucleotide diversity in the South Kazakh Merino (SKM) breed (0.047), while the lowest diversity was observed in the Edilbay breed (0.029). In addition, the average number of nucleotide differences (Kxy) and the average number of nucleotide substitutions (Dxy) were determined among the studied breeds. The minimal value of genetic distance was observed between Akzhayik mutton-wool and Kazakh fat-rumped semi-course-wool breeds (Kxy: 16.956 and Dxy: 0.039), while the maximum value was observed between the Edilbay and SKM breeds (Kxy: 24.600 and Dxy: 0.040). Phylogenetic analysis revealed the presence of three haplogroups, namely, A, B and C in the collected sample, while the haplogroups D and E were not found. The results indicated that 28 of 64 tested animals belong to haplogroup A (43.75%), whereas 25 of investigated animals were attributed to haplogroup B (39.06%) and 11 animals to haplogroup C (17.19%).