Muscle development in Ciona intestinalis requires the b-HLH myogenic regulatory factor gene Ci-MRF
Muscle development in Ciona intestinalis requires the b-HLH myogenic regulatory factor gene Ci-MRF
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DOI：
10.1016/j.ydbio.2006.09.043
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发表时间：
2007-02-01
影响因子：
2.7
通讯作者：
Yasuo, Hitoyoshi
中科院分区：
文献类型：
--
作者：
Meedel, Thomas H.;Chang, Patrick;Yasuo, Hitoyoshi
成肌调节因子（MRF）基因的活性对脊椎动物肌肉发育至关重要，而无脊椎动物肌肉发育在很大程度上不依赖于MRF功能。这种差异表明，在这两组动物中，肌生成是由不同的调节机制控制的。在这里，我们使用过表达和基因敲除来研究无脊椎动物脊索动物玻璃海鞘（Ci-MRF）单个MRF基因在胚胎肌发生中的作用。将Ci-MRF mRNA注射到鸡蛋中导致胚胎肌肉特异性基因活性增加，并通过诱导四种肌肉标记基因（乙酰胆碱酯酶、肌动蛋白、肌钙蛋白1和肌球蛋白轻链）在非肌肉谱系中的表达来揭示Ci-MRF的成肌活性。相反，用反义吗啉代抑制Ci-MRF活性下调这些基因的表达。与吗啉代对肌肉基因活性的影响一致，由吗啉代注射产生的幼虫瘫痪，它们的“肌肉”细胞缺乏肌原纤维。我们的结论是，Ci-MRF是所需的幼虫尾肌的发展，因此，MRF依赖的生肌调控网络可能存在于被囊动物和脊椎动物的祖先。这种可能性提出了一个问题，即最早的肌源性调节网络是MRF依赖性的还是MRF独立性的。(c)2006年爱思唯尔公司All rights reserved.
The activity of myogenic regulatory factor (MRF) genes is essential for vertebrate muscle development, whereas invertebrate muscle development is largely independent of MRF function. This difference indicates that myogenesis is controlled by distinct regulatory mechanisms in these two groups of animals. Here we used overexpression and gene knockdown to investigate the role in embryonic myogenesis of the single MRF gene of the invertebrate chordate Ciona intestinalis (Ci-MRF). Injection of Ci-MRF mRNA into eggs resulted in increased embryonic muscle-specific gene activity and revealed the myogenic activity of Ci-MRF by inducing the expression of four muscle marker genes, Acetylcholinesterase, Actin, Troponin 1, and Myosin Light Chain in non-muscle lineages. Conversely, inhibiting Ci-MRF activity with antisense morpholinos down-regulated the expression of these genes. Consistent with the effects of morpholinos on muscle gene activity, larvae resulting from morpholino injection were paralyzed and their "muscle" cells lacked myofibrils. We conclude that Ci-MRF is required for larval tail muscle development and thus that an MRF-dependent myogenic regulatory network probably existed in the ancestor of tunicates and vertebrates. This possibility raises the question of whether the earliest myogenic regulatory networks were MRF-dependent or MRF-independent. (c) 2006 Elsevier Inc. All rights reserved.