Polymorphism Detection For GPAM Gene And Its Gene Silencing Effect On Lipid Metabolism In Cattle

Simmental originated in Switzerland, divided into milk type, both milk andmeat type. Chinese Simmental imported from Switzerland, which had become alarge meat and milk cattle after several generations of hybridvarieties. The proteinenzyme from this gene, glycerol-3-phosphate acyltransferase mitochondrial (GPAM),catalyzes the first committed step in triglyceride (TAG) and phospholipidbiosynthesis. GPAM acts both centrally and peripherally, and regulates adiposity,energy expenditure, body weight, milk production, and overall metabolism.In the present study, in order to reveal the correlation between GPAMgene exon composition and meat quality traits and polymorphism of SimmentalCattle Carcass, PCR-RFLP technique was used to analyze the association of twonovel single nucleotide polymorphisms (SNPs) in the coding region (exon20th) ofglycerol-3-phosphate acyltransferase, an important player in de novo lipogenesis,with adipogenesis traits and other economical traits (carcass and meat quality traits)of Chinese Simmental-cross steers. Statistical analysis of45indicators, revealed thatthe C-bearing genotypes (CC or TC) of E20-2823C>T showed higher omasum fatweight, genital fat weight，carcass meat percentage，carcass brisket depth，net weightof bones, skin weight, forepaw weight and hind-feet weight (p<0.05). The A-bearinggenotypes (AA or GA) of E20-3386G>A also showed higher net weight of bones,meat-bone ratio, marbling score, omasum fat weight (p<0.05).The correlation of GPAM with adipogenesis traits and other economical traitswas also examined in vitro by liposome mediated RNA interference (RNAi) toknockdown the expression of endogenous GPAM in bovine embryonicfibroblast cells (BEFC), which indicated that knockdown of GPAM expression significantly reduced triglyceride (TAG) content in BEFCs. GPAM gene might play acritical role in regulating animal fat metabolism.