Association of IGF1R Polymorphisms with Growth Traits and its Expression Profiles in Different Pig Breeds

Insulin-like growth factor 1 receptor (IGF1R) is one component of insulin-like growth factor system, which has biological functions of growth traits. The aim of this study is to investigate the entire exons of IGF1R in the three commercial pig breeds, Duroc, Yorkshire and Landrace, to identify novel single nucleotide polymorphisms and their correlation with growth traits. One novel SNP (c.3678C>T) in the exon 20 was detected. This SNP caused the change of amino acid (Ser1217Phe), a portion of cytoplasmic tyrosine kinase domain of IGF1R. At the c.3678C>T site, three genotypes were significantly associated with average daily gain at different growth stage in Yorkshire and Landrace breeds. Meanwhile, we identified the differently expressed pattern of IGF1R in muscle of Yorkshire and Jinhua pigs at different growth stages. Our results provide useful information on understanding the effect of porcine IGF1R gene on growth. The novel IGF1R polymorphism may be useful as molecular markers in pig selection but future studies are required.