Genome-Wide Association Study on Body Weight Reveals Major Loci on OAR6 in Australian Merino Sheep

Abstract

Body weight (BW) is an important trait for meat production in sheep. In order to clarify genes and chromosomal regions that might be associated with body weight in sheep, a genome-wide association study using Illumina 50K Ovine SNP chip on a population of 1,743 Australian Merino sheep was carried out. A total of 39 SNPs were found to be associated with BW at Bonferroni-corrected genome-wide significance of 1%. One region on OAR6, between 40.3 Mb and 42.9 Mb, included 13 significant SNPs that were identified as being associated with the trait. The most significant SNP (OAR6_41936490.1) has 2.11 kg of allele substitution effect, while the second most significant SNP (s17946.1) has 2.13 kg of effect on body weight. These correspond to 24.33% and 24.57%, respectively, of the phenotypic standard deviations for BW in Australian Merino sheep.