Expression of fat deposition and fat removal genes is associated with intramuscular fat content in longissimus dorsi muscle of Korean cattle steers
Expression of fat deposition and fat removal genes is associated with intramuscular fat content in longissimus dorsi muscle of Korean cattle steers
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DOI：
10.2527/jas.2011-4753
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发表时间：
2012-06-01
影响因子：
3.3
通讯作者：
Baik, M.
中科院分区：
文献类型：
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作者：
Jeong, J.;Kwon, E. G.;Baik, M.
牛肌内脂肪是影响肉质性状的重要组成部分。我们测量了韩国阉牛的胴体特征和基因表达，通过确定IMF含量和基因表达丰度之间的相关性，并通过开发模型来预测IMF含量，从而阐明LM组织中IMF沉积的分子机制。IMF的沉积取决于LM中脂肪沉积和脂肪去除之间的平衡。我们测量了脂质代谢基因的mRNA丰度，包括脂肪生成[乙酰辅酶A羧化酶（ACC），脂肪酸合成酶（FATs）]，脂肪脂质摄取[脂蛋白脂酶（LPL），脂肪酸转位酶（CD 36），脂肪酸转运蛋白1（FATP 1）]，脂肪酸酯化[甘油-3-磷酸酰基转移酶1（GPAT 1），酰基甘油磷酸酰基转移酶1（AGPAT 1），二酰基甘油酰基转移酶1（DGAT 1）、DGAT 2]、脂解[脂肪甘油三酯脂肪酶（ATGL）、脂肪酶敏感性脂肪酶（HSL）、单甘油酯脂肪酶（MGL）]和脂肪酸氧化[肉毒碱棕榈酰转移酶1B、极长链酰基辅酶A脱氢酶（VLCAD）、中链酰基辅酶A脱氢酶（MCAD）]。在9个脂肪沉积基因中，GPAT 1基因mRNA丰度与IMF含量的相关性最大（r = 0.74; P < 0.001）。脂肪沉积相关基因ACC、FATP 1、LPL、CD 36、FATP 1、AGPAT 1、DGAT 1和DGAT 2的表达丰度与LM中IMF含量呈显著正相关（P < 0.05）。在6个脂肪去除基因中，ATGL mRNA丰度与LM中IMF含量呈最大负相关（r = -0.68; P < 0.001）。MGL、VLCAD和MCAD等其他去脂基因的表达与IMF含量呈显著负相关（P < 0.05）。我们的研究结果表明，增加脂肪生成，脂肪酸吸收，脂肪酸酯化，并减少脂解和脂肪酸氧化的综合影响，有助于增加IMF沉积在韩国阉牛。多元回归分析显示，在15个脂代谢基因中，LM中GPAT 1基因的mRNA丰度是预测IMF含量的第一主要变量（54%）。其次是ATGL的mRNA丰度（11%）。总之，这些结果表明，GPAT 1和ATGL基因可以作为遗传标记来预测IMF沉积在LM。
Intramuscular fat (IMF) in cattle is an important component of traits that influence meat quality. We measured carcass characteristics and gene expression in Korean steers to clarify the molecular mechanism(s) underlying IMF deposition in LM tissue by determining the correlation between IMF content and gene expression abundance and by developing models to predict IMF content using gene expression abundance. The deposition of IMF is determined by a balance between fat deposition and fat removal in the LM. We measured mRNA abundance of lipid metabolic genes including lipogenesis [acetyl CoA carboxylase (ACC), fatty acid synthase (FASN)], fatty lipid uptake [lipoprotein lipase (LPL), fatty acid translocase (CD36), fatty acid transport protein 1 (FATP1)], fatty acid esterification [glycerol-3-phosphate acyltransferase 1 (GPAT1), acylglycerol phosphate acyltransferase 1 (AGPAT1), diacylglycerol acyltransferase 1 (DGAT1), DGAT2], lipolysis [adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), monoglyceride lipase (MGL)], and fatty acid oxidation [carnitine palmitoyl transferase 1B, very long-chain acyl-CoA dehydrogenase (VLCAD), medium-chain acyl-CoA dehydrogenase (MCAD)] in the LM. The mRNA abundance of the GPAT1 gene showed the greatest correlation (r = 0.74; P < 0.001) with IMF content among 9 fat deposition genes. The gene expression abundance of other fat deposition genes including ACC, FASN, LPL, CD36, FATP1, AGPAT1, DGAT1, and DGAT2 also exhibited significant positive correlations (P < 0.05) with IMF content in the LM. Conversely, ATGL mRNA abundance showed the greatest negative correlation (r = -0.68; P < 0.001) with IMF content in the LM among 6 fat removal genes. The expression of other fat removal genes including MGL, VLCAD, and MCAD showed significant negative correlations (P < 0.05) with IMF content. Our findings show that the combined effects of increases in lipogenesis, fatty acid uptake, fatty acid esterification, and of decreases in lipolysis and fatty acid oxidation contribute to increasing IMF deposition in Korean steers. The multiple regression analysis revealed that the mRNA abundance of the GPAT1 gene in the LM was the first major variable predicting IMF content (54%) among 15 lipid metabolic genes. The second was mRNA abundance of ATGL (11%). In conclusion, these results suggest that GPAT1 and ATGL genes could be used as genetic markers to predict IMF deposition in the LM.