Sadkowski T, Jank M, Zwierzchowski L, Oprzadek J, Motyl T
Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences (SGGW), Warsaw, Poland.
J Appl Genet. 2009;50(2):109-23. doi: 10.1007/BF03195662.
A cDNA microarray (18 263 probes) was used for transcriptome analysis of bovine skeletal muscle (m. semitendinosus) in 12-month-old bulls of the beef breed Limousin (LIM) and the typical dairy breed Holstein-Friesian (HF, used as a reference). We aimed to identify the genes whose expression may reflect the muscle phenotype of beef bulls. A comparison of muscle transcriptional profiles revealed significant differences in expression of 393 genes between HF and LIM. We classified biological functions of 117 genes with over 2-fold differences in expression between the examined breeds. Among them, 72 genes were up-regulated and 45 genes were down-regulated in LIM vs. HF. The genes were involved in protein metabolism and modifications (22 genes), signal transduction (15), nucleoside, nucleotide and nucleic acid metabolism (13), cell cycle (9), cell structure and motility (9), developmental processes (9), intracellular protein traffic (7), cell proliferation and differentiation (6), cell adhesion (6), lipid, fatty acid and steroid metabolism (5), transport (5), and other processes. For the purpose of microarray data validation, we randomly selected 4 genes: trip12, mrps30, pycrl, and c-erbb3. Real-time RT-PCR results showed similar trends in gene expression changes as those observed in microarray studies. Basing on results of the present study, we proposed a model of the regulation of skeletal muscle growth and differentiation, with a principal role of the somatotropic pathway. It may explain at least in part the development of muscle phenotype in LIM bulls. We assume that the growth hormone directly or indirectly (through IGF-1) activates the calcium-signaling pathway with calcineurin, which stimulates myogenic regulatory factors (MRFs) and inhibits early growth response gene. The inhibition results in indirect activation of MRFs and impaired activation of TGF-beta1 and myostatin, which finally facilitates terminal muscle differentiation.
利用cDNA微阵列（18263个探针）对利木赞肉牛品种（LIM）12月龄公牛和典型奶牛品种荷斯坦-弗里生牛（HF，用作对照）的半腱肌进行转录组分析。我们旨在鉴定那些表达可能反映肉牛公牛肌肉表型的基因。肌肉转录谱的比较揭示了HF和LIM之间393个基因表达的显著差异。我们对所检测品种间表达差异超过2倍的117个基因的生物学功能进行了分类。其中，与HF相比，LIM中有72个基因上调，45个基因下调。这些基因参与蛋白质代谢和修饰（22个基因）、信号转导（15个）、核苷、核苷酸和核酸代谢（13个）、细胞周期（9个）、细胞结构和运动（9个）、发育过程（9个）、细胞内蛋白质运输（7个）、细胞增殖和分化（6个）、细胞黏附（6个）、脂质、脂肪酸和类固醇代谢（5个）、运输（5个）以及其他过程。为了验证微阵列数据，我们随机选择了4个基因：trip12、mrps30、pycrl和c-erbb3。实时逆转录聚合酶链反应结果显示基因表达变化趋势与微阵列研究中观察到的相似。基于本研究结果，我们提出了一个骨骼肌生长和分化调控模型，其中生长激素途径起主要作用。这至少可以部分解释LIM公牛肌肉表型的形成。我们假设生长激素直接或间接（通过胰岛素样生长因子-1）激活与钙调神经磷酸酶相关的钙信号通路，后者刺激生肌调节因子（MRFs）并抑制早期生长反应基因。这种抑制导致MRFs的间接激活以及转化生长因子-β1和肌肉生长抑制素的激活受损，最终促进终末肌肉分化。
