Investigating the impact of alle frequencies on genomic variance components for body weight in Suffolk sheep using SNP data

Since SNP markers in genomic selection spread across the genome, they may potentially explain all of genetic variation. In this study, genotype data from Suffolk sheep, genotyped by 50k Illumina SNP chip were used. Birth weight and weaning weight traits were studied in this research. Quality control for minor allele frequency at two thresholds, one and five percent were studied. To study the association between allele frequency spectrum and captured additive genetic variance, all SNPs were partitioned in five MAF bins with the equal numbers of SNPs. The analysis were performed using GREML approach via GCTA method. Using all SNPs with MAF>0.01 estimates of genomic heritability were 0.45 and 0.19 for birth weight and weaning weight, respectively. For MAF>0.05 these values were 0.42 and 0.18 respectively. The contribution of different groups of SNPs with rare allele frequency in justifying genetic variation for the two traits was different. In general, a significant portion of the genetic variance was explained by SNPs with a MAF