SNP identification in swine candidate genes for meat quality

An important aim of Italian pig selection is to obtain animals having high aptitude for protected designation of origin (PDO) dry-cured ham production. The efforts of the last years were directed to single nucleotide polymorphisms (SNPs) identification for large-scale association studies. In this work, SNPs in seven candidate genes for meat quality traits (inositol polyphosphate-1-phosphatase, INPP1, phosphatidylinositol 3-kinases, PIK3R2, protein tyrosine phosphatase receptor type D, PTPRD, phospholipase C gamma 1, PLCG1, CASP2 and RIPK1 domain containing adaptor with death domain, CRADD, cyclin-dependent kinase inhibitor 1C, CDKN1C, calpain, small subunit 1, CAPNS1) were found analyzing 22 animals representing the extreme tails of the distribution for phenotypes related to meat quality of 231 Large White×Landrace individuals. Association analysis revealed that the CRADD c.343A>G SNP was significant associated with muscle compactness, and the PTPRD c.2449C>A polymorphism and the PIK3R2 c.2966C>T SNP with muscle compactness and backfat thickness. The five SNPs were then analyzed in 560 Italian Large White with extreme EBVs for fat thickness and in 600 individuals belonging to three Italian breeds (Large White, Duroc, Landrace), with extreme estimated breeding values (EBVs) for fat or growth traits. The PIK3R2 c.2966C>T mutation showed significant associations with backfat thickness, average daily gain, feed conversion rate and lean cut yield. The PTPRD c.2680C>T SNP showed a significant association with thigh weight in Large White individuals.