PSXI-6 - Genome-wide SNP analysis of three Azerbaijani sheep breeds

Azerbaijani sheep breeds are of particular interest since this region is in close proximity to the Fertile Crescent – the proposed place of domestication. Molecular genetic studies of local breeds will help shed light on the history of sheep breeding. Our work was aimed to identify genetic characteristics of three sheep breeds from Azerbaijan: Bozakh (n = 19), Karabakh (n = 16) and Mazekh (n = 19). For genotyping, we used Illumina OvineHD BeadChip (AgResearch) containing around 600 thousand SNPs. PLINK 1.9 was used to perform quality control. Genetic diversity parameters and pairwise F_ST distances were calculated in R package diveRsity. After all quality control procedures, including LD pruning, 286663 SNPs were selected for subsequent analyses. PCA revealed that, while all the breeds formed their own clusters, only 1.62% of genetic variability was explained by the first component (PC1). Cluster analysis conducted in Admixture 1.3 showed that Bozakh was derived from Karabakh and Mazekh breeds. However, based on CV error, the number of clusters (K) judged to be one. Pairwise F_ST distances were quite low, with highest value of 0.017 between Karabakh and Mazekh and lowest (0.006) between Mazekh and Bozakh breeds. The global fixation index (F_ST) was 0.01, which indicated that 99% of genetic variability was due to within breeds differences. Expected heterozygosity was similar in Bozah and Mazeh (0.363±0.000 and 0.360±0.000, respectively) and a slight lower in Karabakh breed (0.353±0.000). We observed neither heterozygotes excess nor deficiency in all of the studied breeds. The inbreeding coefficient (Fis), ranged from 0.001 in Karabakh to 0.011 in Mazekh sheep. Our results demonstrate that the studied Azerbaijani sheep breeds are genetically close, but carry specific genomic components that allows consider them as valuable genetic resources. The study was funded by the RSF 21-66-00007 (genotyping) and the Russian Ministry of Science and Higher Education 0445-2019-0024 (expedition studies).