Genetic Variation in the Bovine IWS1 Gene

Our previous genome-wide scan identified a putative parent-of-origin effect quantitative trait locus (POE-QTL) in the proximal end of bovine chromosome 2 affecting postnatal growth in cattle. We also identified the homolog of Saccharomyces cerevisiae serine protease inhibitor 1 (SPN1 also known as IWS1) in this region. IWS1 is part of a transcription factor complex that regulates transcription. In this study we have amplified and sequenced 1,102 bp fragment spanning exon 5, 6 and intron 5 of IWS1 gene in 54 animals from 18 cattle breeds from Africa, Asia and North America. We identified 11 SNPs and a 3bp deletion. Exon 5 was conserved in all 18 breeds. Intron 5 has 9 SNPs and one 3 bp deletion while exon 6 has 2 SNPs which are non-synonymous and in-silico functional analysis of these two SNPs using PANTHER showed that they have deleterious effects on protein structure. These novel SNPs in bovine IWS1 gene may be associated with growth and body composition in cattle.