Polymorphism of DGAT1 associated with intramuscular fat‐mediated tenderness in sheep

Abstract

AbstractBACKGROUND: Polymorphism of acyl coenzyme A: diacylglycerol acyltransferase 1 (DGAT1) affects the fat content of milk and meat in cattle. To investigate the effects of DGAT1 on sheep meat quality traits, the cDNA of DGAT1 was cloned. The association between single nucleotide polymorphisms of the DGAT1 gene and sheep meat quality traits was assessed.RESULTS: Sequence analysis showed that sheep DGAT1 is about 1470 bp and contains an open reading frame coding for a protein of 489 amino acids. A silent mutation of GCT (Ala487) to GCC (Ala487) was found in exon 17 at the 1461st base pair in 286 lambs of three Chinese breeds by polymerase chain reaction single nucleotide conformation polymorphism assay. The mutation was confirmed by Alu I polymerase chain reaction restriction fragment length polymorphism assay. The association between genotypes and meat quality traits in the longissimus thoracis et lumborum muscle was analysed. The TT genotype conferred higher muscle marbling score (P < 0.05) and intramuscular fat (IMF) content (P < 0.05) and lower shear force (P < 0.05) and drip loss rate (P < 0.01).CONCLUSION: The T allele had a positive effect on tenderness, IMF content and marbling score in sheep meat. The results of this study suggest that the TT genotype of DGAT1 could be regarded as a molecular marker for meat tenderness and IMF content in sheep. Copyright © 2008 Society of Chemical Industry