Genome-wide association study on growth traits in Colombian Hair Sheep

The Colombian hair sheep have characteristics of great interest, among the following: high capacity for adaptation, good fertility, high prolifically, and low presence of diseases, which have been little studied. Currently, genome-wide association studies (GWAS) have been widely used to detect and locate candidate genes. However, in sheep, there is a low number of investigations carried out in GWAS, because the available information is limited, compared to that of other species. This research aimed to conduct a genome wide association study on muscle growth traits using the Illumina OvineSNPs50 BeadChip array. A GWAS using 54.241 single nucleotide polymorphisms (SNPs) was conducted in Ethiopian (44 individuals), Sudan (63), and Pelibuey (60) breeds of Creole hair sheep to evaluate eight growth traits. Quality control was performed using a linear regression model in PLINK. Moreover, a functional analysis was done in the KEGG database using the Ovis aries (sheep) genome v.3.1. In total, 44.396 SNPs that passed quality control were used for the analysis. The 10 most significant SNPs were identified for each trait. The functional analysis allowed the annotating of four candidate genes, namely CEP135, EMCN, PAM, and PIAS2, as the most relevant genes for the traits assessed. Additionally, 27 genes associated with phenotypic traits were considered promising and could also be influencing growth traits. This is the first GWAS on Colombian hair sheep to report genomic traits associated with muscle growth traits. Four candidate genes (CEP135, EMCN, PAM, and PIAS2) associated with eight growth traits were identified by genome-wide association in colombian hair sheep.