Galanin Receptor 2 and Its Gene Interactions Affect Lean Yield and Marbling in Beef Steers

Previously, several gene variants have been associated with marbling and lean meat yield. LEPc.73C>T, ADH1Cc.-64T>C, TG5, and GALR2c.-199T>G are gene variants that influence marbling, whereas CRHc.22C>G, POMCc.288C>T, MC4Rc.856C>G and IGF2c.-292C>T affect lean yield. The purpose of the current study was to assess combinations of marbling gene variants with those associated with lean yield to potentially increase both attributes. These gene variants were genotyped in 386 crossbred steers and evaluated for associations with carcass traits. The variants for marbling with lean yield showed a negative correlation. GALR2c.-199T>G showed significant interactions or trends with CRHc.22C>G, POMCc.288C>T and IGF2c.-292C>T with average fat, grade fat, REA and cutability. These four gene variants were selected for genotyping in 2000 crossbred steers, 1000 of which were implanted and 1000 hormone free, to validate the correlation. Presently, only GALR2c.-199T>G genotypes have been analyzed with carcass data in this population. There was a significant association for marbling with implant status of the steers (P<0.0001) and with the GALR2c.-199T>G genotype (P<0.0001) where each T allele was associated with an increase in intramuscular fat. When GALR2c.-199T>G was paired with each lean yield variant, a significant association or trend with several carcass traits was observed. The other three selected gene variants have yet to be assessed in this larger population. GALR2c.-199T>G can affect marbling and lean yield traits singularly or paired with other variants.