Myogenesis in paraxial mesoderm: preferential induction by dorsal neural tube and by cells expressing Wnt-1.
Myogenesis in paraxial mesoderm: preferential induction by dorsal neural tube and by cells expressing Wnt-1.
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发表时间：
1995-11
期刊：
影响因子：
4.6
通讯作者：
H. M. Stern;A. Brown;S. Hauschka
中科院分区：
文献类型：
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作者：
H. M. Stern;A. Brown;S. Hauschka
以往的研究表明，神经管/脊索复合体是骨骼肌发育所必需的体节内。为了探索肌源性诱导信号在神经管中的定位，将背侧或腹侧神经管与单个体节或节段板中胚层片接触培养。肌球蛋白重链免疫染色显示，与神经管背侧半段培养的体节和节段板的肌源性反应率分别为70%和85%。该反应略低于对整个神经管/脊索的100%反应，但远大于对腹神经管有和没有脊索的30%和10%肌源性反应。这些结果表明，背神经管发出一个强大的肌源性诱导信号，占整个神经管/脊索的大部分诱导活动。然而，当背神经管和腹神经管/脊索都存在时，腹神经管/脊索在体节肌源性诱导中的作用从诱导的大量肌源性细胞中明显可见。为了解决一个特定的背神经管因子在体节成肌诱导中的作用，我们测试了表达Wnt-1的成纤维细胞在体外促进近轴中胚层成肌的能力。我们发现，表达Wnt-1的细胞诱导少量体节和节段板细胞进行肌发生。这一发现与上述局部背神经管诱导活性一致，但由于腹神经管/脊索也具有肌源性诱导能力，但不表达Wnt-1，因此可能涉及其他诱导因子。
Previous studies have demonstrated that the neural tube/notochord complex is required for skeletal muscle development within somites. In order to explore the localization of myogenic inducing signals within the neural tube, dorsal or ventral neural tube halves were cultured in contact with single somites or pieces of segmental plate mesoderm. Somites and segmental plates cultured with the dorsal half of the neural tube exhibited 70% and 85% myogenic response rates, as determined by immunostaining for myosin heavy chain. This response was slightly lower than the 100% response to whole neural tube/notochord, but was much greater than the 30% and 10% myogenic response to ventral neural tube with and without notochord. These results demonstrate that the dorsal neural tube emits a potent myogenic inducing signal which accounts for most of the inductive activity of whole neural tube/notochord. However, a role for ventral neural tube/notochord in somite myogenic induction was clearly evident from the larger number of myogenic cells induced when both dorsal neural tube and ventral neural tube/notochord were present. To address the role of a specific dorsal neural tube factor in somite myogenic induction, we tested the ability of Wnt-1-expressing fibroblasts to promote paraxial mesoderm myogenesis in vitro. We found that cells expressing Wnt-1 induced a small number of somite and segmental plate cells to undergo myogenesis. This finding is consistent with the localized dorsal neural tube inductive activity described above, but since the ventral neural tube/notochord also possesses myogenic inductive capacity yet does not express Wnt-1, additional inductive factors are likely involved.