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ABSTRACT: Western and indigenous Chinese pig breeds show obvious differences in muscle growth and meat quality, however, the underlying molecular mechanism remains unclear. The main objective of this study was to evaluate the breed-specific mechanisms controlling meat quality and postmortem muscle metabolism. The specific purpose was to investigate the variations in meat quality, muscle fiber type, and enzyme activity between local Jinhua and exotic Landrace pigs at the same age (180 d of age), as well as the same BW of 64 kg, respectively. We compared differentially expressed muscle fiber types such as types I and IIa (oxidative), type IIb (glycolytic), as well as type IIx (intermediate) fibers in LM and soleus muscles of Jinhua and Landrace pigs using real-time reverse-transcription PCR. Furthermore, the metabolic enzyme activities of lactate dehydrogenase, as well as succinic dehydrogenase and malate dehydrogenase, were used as markers of glycolytic and oxidative capacities, respectively. Results showed that Jinhua pigs exhibited greater intramuscular fat content and less drip loss compared with the Landrace (P < 0.01). Meanwhile, the mRNA abundance of oxidative and intermediate fibers was increased in Jinhua pigs, whereas the glycolytic fibers were more highly expressed in the Landrace (P < 0.01). In addition, Jinhua pigs possessed greater oxidative capacity than that of the Landrace (P < 0.05). These results suggested that the increased expression of the oxidative and intermediate fibers and greater activities of oxidative enzymes in Jinhua pigs were related to meat quality as indicated by a greater intramuscular fat and reduced drip loss. Based on these results, we conclude that muscle fiber composition and postmortem muscle metabolism can explain, in part, the variation of meat quality in Jinhua and Landrace pigs. These results may provide valuable information for understanding the molecular mechanism responsible for breed specific differences in growth performance and meat quality.
Journal of Animal Science 10/2010; 89(1):185-91. · 2.10 Impact Factor
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ABSTRACT: Adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) are major novel triglyceride lipases in animals. The aim of this study was to determine if there are differences in the porcine ATGL (pATGL) and HSL genes between Jinhua pigs (a fatty breed) and Landrace pigs (a leaner breed). In addition, the effect of TNFalpha and pATGL-specific siRNA (pATGL-siRNA) on the expression of pATGL and HSL in porcine adipocytes was also examined. Compared with Landrace pigs, the body weight (BW) of Jinhua pigs was lower (P < 0.01), while intramuscular fat content (in the longissimus dorsi muscle), as well as the back fat thickness and body fat content were higher (P < 0.01). The expression of pATGL and HSL mRNA in Jinhua pigs was lower (P < 0.01) in subcutaneous adipose tissue, and greater (P < 0.01) in longissimus dorsi muscle compared with Landrace pigs. In vitro treatment of porcine adipocytes with TNFalpha decreased (P < 0.01) the glycerol release and the gene expression of pATGL, HSL and PPARgamma in porcine adipocytes. Furthermore, transfection with pATGL-siRNA significantly decreased (P < 0.01) the expression of pATGL, while it had no effect on the expression of HSL. Treatment with 25 ng/ml TNFalpha in conjunction with pATGL-siRNA significantly decreased (P < 0.01) the expression of pATGL and HSL in cultured porcine adipocytes. These results provide useful information to further the understanding of the function of pATGL and HSL in porcine lipid metabolism, which should be applicable to the regulation of fat deposition and improvement of meat quality.
Animal Genetics 07/2009; 40(6):863-70. · 2.40 Impact Factor
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ABSTRACT: Adipose triglyceride lipase (ATGL) was recently identified and described as a major novel triglyceride lipase in animals. In this study, we aimed to study the tissue-specific and developmental expression pattern of porcine ATGL (pATGL) and the effect of resveratrol (RES) on expression of pATGL in vitro. The full-length cDNA sequence of pATGL was 1,958 bp (accession no. EF583921), with a 1,458-bp open reading frame encoding a 486-AA protein (the predicted molecular mass of 53.2 kDa, accession no. ABS58651). Comparison of the deduced AA sequence with the bovine, mouse, rat, dog, and human adipose triglyceride lipase showed 87, 84, 83, 81, and 80% similarity, respectively. Furthermore, the pATGL was highly expressed in porcine adipose tissue, to a lesser degree in kidney, heart, and muscle, and least but detectable in brain. In s.c. adipose tissue, pATGL mRNA was low at birth (1 kg of BW) and then increased, reaching a maximal value at 20 kg of BW (approximately 8 wk old; P < 0.01). In peritoneal and omental adipose tissue, the greatest expression of pATGL was observed at 40 kg of BW (approximately 12 wk old). In vitro, exposure of cultured adipocytes to 40 and 80 muM RES for 24 h increased the mRNA levels of pATGL by 95.3% (P < 0.05) and 146.8% (P < 0.01), respectively. Accordingly, lipid accumulation was decreased by 25.7% (P < 0.05) and 60.8% (P < 0.01), respectively. When treated with RES for 48 h, the mRNA levels of pATGL were increased by 104.1% (P < 0.05) and 163.1% (P < 0.01), respectively. As expected, lipid accumulation was decreased by 9.7% (P > 0.05) and 29.0% (P < 0.05), respectively. These results add to our understanding of the role of pATGL in adipose tissue development and as a potential target for regulating fat deposition and meat quality.
Journal of Animal Science 04/2008; 86(8):1781-8. · 2.10 Impact Factor
