Study of SNPs associated with carcass fat in Afshari,Moghani and Qezel sheep breeds

Identification of genomic regions controlling economic traits is one of the most challenging uses of dense markers in animal genetics. Fat storage is economically important for breeding sheep. Therefore, identification of lipid-associated gene positions was the main goals of this study.In this study, 49034 Single Nucleotide Polymorphisms (SNPs) were used to identify the genomic regions affecting fat deposition of 106 sheep individuals include Afshari (n=37), Moghani (n=34) and Qezel (n=35) breeds were used. All samples were genotyped by Illumina OvineSNP50K bead chip. By running the quality control on the raw genotype, from tolal 49,034 SNP markers only 46,676 SNPs remained then genomic relationship principal component analysis (PCA) was used in order to assign correct individual to each breed. Theta and Fst analysis were applied to survey the population differentiation in three breeds, so five regions in 99.99 percentile FST score of the genome distribution were selected for further analysis. These regions are stated on chromosomes number 3, 13 (two areas), 15 and 22 were associated with LDL and HDL receptors Lipolise regulation in fat cells and fatty acid metolism. To verify those regions, Extended Haplotype Homozygosity (EHH) test based on linkage disequilibrium was perform. The results of this study shows that SNP bead chip are useful for population differentiation and GWAS so this can help us to achive an genetic improvement by genomic selection.