Abstract：The final and critical step in the synthesis of triglycerides is catalyzed by two acyl-coA∶diacylglycerol acyltransferase (DGAT) enzymes, i.e. DGAT1 and DGAT2. Analysis on the developmental expression of DGAT1 and DGAT2 mRNA in porcine backfat tissues is a prerequisite for the identification of genes underling fat deposition differences between Chinese indigenous fat-type and western lean-type pig breeds. The DGAT1 and DGAT2 mRNA expression in backfat tissues of Laiwu and Duroc 3-day-old piglets and adults was investigated by both RT-PCR and Real-time fluorescent quantitative RT-PCR in this study. The results indicated that, DGAT1 mRNA expression in backfat tissues was higher in adult pigs than that of 3-day-old piglets, which is 5.0-fold and 2.7-fold for Laiwu and Duroc pig, respectively. DGAT2 mRNA expression in backfat tissues was higher in adult pigs than that of 3-day-old piglets, which is 27.6-fold (P<0.01) and 4.8-fold (P<0.05) for Laiwu and Duroc pig, respectively. The increase in mRNA expression in adult backfat tissues was higher for DGAT2 than that of DGAT1. For DGAT2 expression in Duroc backfat tissues, it was higher in 3-day-old piglets, but lower in adults than that of Laiwu pigs, although the difference was not significant (P>0.05). These results suggest that DGAT2, not DGAT1, likely controls the differences in fat deposition.
