The effects of DGAT1 and DGAT2 mRNA expression on fat deposition in fatty and lean breeds of pig

Diacylgycerol acyltransferase (DGAT) plays a key modulatory role in animal fat deposition. Intramuscular fat (IMF) content and backfat thickness (BFT) were important factors in establishing pork quality. Therefore, the objectives of the current study were to elucidate the relationship between DGAT mRNA expression with IMF content, BFT by quantitative real-time PCR in three important pig breeds, including Laiwu pig (LW, n = 12, fatty), Lulai Black (LL, n = 12) and Large White (LY, n = 12, lean). A total of 36 pigs were castrated boars (114 ± 2 kg) and taken from longissimus dorsi muscle, backfat and liver. Results showed that the mRNA level of DGAT was maximal in LW, the minimal in LY. Finally, the expression of DGAT1 gene was positively correlated with BFT and not IMF; DGAT2 gene was positively correlated with IMF and not BFT. The results indicated that the two genes have a different function in fat deposition; in addition, the IMF contents were significantly different among breeds (P < 0.01), and not significantly different among BFT (P > 0.05). Based on results of DGAT1 and DGAT2 expression we suggested that the function of IMF and BFT was not the same and the deposition of IMF and BFT was regulated by different mechanisms.