Meat Sci. 2015 Feb;100:237-45. doi: 10.1016/j.meatsci.2014.10.012.
Localization and abundance of early markers of adipogenic differentiation were investigated in bovine muscle tissue to verify their association with marbling development. Bovine skeletal muscle samples were used for immunohistochemical localization and measurement of mRNA and protein abundance of delta-like homolog 1 (DLK1) and CCAAT/enhancer-binding protein beta (CEBPB). The localization of DLK1-positive cells confirmed the position of small clusters of adipocytes which can be considered as the origin of marbling flecks. The results indicated higher DLK1 expression in the less marbled muscle of Holstein (HS) steers (P < 0.05) and a trend to higher CEBPB expression in Japanese Black (JB) steers (P < 0.1) at slaughter. The number of DLK1-positive cells and fat content were negatively correlated. The lower expression of DLK1 together with higher CEBPB abundance during fattening in JB may have contributed to the development of more adipocytes in the skeletal muscle of JB.
本研究旨在探讨牛肌肉组织中脂肪生成早期标志物的定位和丰度，以验证其与大理石花纹发育的关系。使用牛骨骼肌样本进行免疫组织化学定位及 delta-like 同源物 1（DLK1）和 CCAAT/增强子结合蛋白β（CEBPB）的 mRNA 和蛋白丰度测量。DLK1 阳性细胞的定位证实了小簇脂肪细胞的位置，这些脂肪细胞可被视为大理石花纹斑点的起源。结果表明，荷斯坦（HS）阉牛的大理石花纹较少的肌肉中 DLK1 表达较高（P < 0.05），屠宰时日本黑牛（JB）阉牛的 CEBPB 表达有升高的趋势（P < 0.1）。DLK1 阳性细胞数与脂肪含量呈负相关。在育肥过程中 JB 的 DLK1 表达较低，同时 CEBPB 丰度较高，这可能导致 JB 骨骼肌中产生更多的脂肪细胞。
