Molecular characterization and association analysis of porcine adipose triglyceride lipase (PNPLA2) gene

The adipose triglyceride lipase (PNPLA2, also known as ATGL) is a novel triacylglycerol (TG) lipase which specifically removes the first fatty acid from the triglyceride molecule generating free fatty acid and diglyceride (DG) in mammalian cells. Here we describe the molecular characterization of the porcine ATGL gene. The full-length cDNA sequence contains a 1,461 bp open reading frame encoding a protein of 486 amino acids with a calculated molecular mass of 53.2 kDa and an isoelectric point of 7.90. The porcine ATGL protein shares high identity with other mammalian ATGL. The ATGL gene contains 9 coding exons, spans approximately 6 kb. The porcine ATGL mRNA was expressed predominantly in backfat, mildly in muscle, small intestine and heart, and almost absent in liver, spleen, lung, stomach, kidney and ovary. Statistical analysis showed the ATGL gene polymorphism (G/A³⁹²) was different between Chinese indigenous and introduced commercial western pig breeds, and was highly associated with almost all the fat deposition and carcass traits, including subcutaneous fat thickness, viscera adipose tissue, lean percentage, loin eye traits and even rib numbers.