PSX-26 The identification of novel SNPs significant for reproductive abilities in sheep using GWAS

Abstract

Abstract Reproductive ability of ewes is one of the most important traits in sheep breeding. Hence the mechanisms underlying this complex trait are poorly understood till now. To study the genetic architecture of litter size and search for SNPs associated with Total lambs born (TLB) we conducted genome-wide association study of Volgograd sheep. A total of 48 sheep after the second lambing were collected: 24 of them had 1 lamb, and 24 others had two lambs. All the samples were genotyped using the OvineSNP50 Genotyping BeadChip according to the manufacturer’s protocol. Then they were filtered using the parameters –hwe = 10–3, --maf = 0.05, --geno = 0.1, --indep-pairwise 50 5 0.5. After the quality control 46249 SNPs of 54241 were retained in the working dataset for the GWAS. A total of 14 significant SNPs located on chromosomes 1, 2, 4, 7, 15, 18, and 19 reached the genome-wide significance level. More than 50% of SNPs are located in the introns of genes, the rest are located in regulatory regions of genes and intergenic regions. We searched for candidate genes located near the significant SNPs using the Ensembl database. A total of 14 genes were selected. Gene annotation was completed using Panther. The detailed information about those significant SNPs and the possible genes associated with TLB are presented in Table. These genes take part in cellular processes, biological regulation and regulation of metabolic processes, some of them are involved in the formation of the immune system and biological adhesion. The data obtained allowed us to determine a number of SNPs that are significant for the formation of such complex reproductive trait as Total lamb born (TLB) in sheep and could be potentially applied in sheep breeding programs.