Activation of different myogenic pathways: myf-5 is induced by the neural tube and MyoD by the dorsal ectoderm in mouse paraxial mesoderm.
Activation of different myogenic pathways: myf-5 is induced by the neural tube and MyoD by the dorsal ectoderm in mouse paraxial mesoderm.
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不同生肌途径的激活：myf-5由神经管诱导，MyoD由小鼠近轴中胚层的背侧外胚层诱导。
作者：
G. Cossu;R. Kelly;S. Tajbakhsh;S. D. Donna;E. Vivarelli;M. Buckingham
新形成的体或未分节的旁轴中胚层（UPM）被单独培养或与邻近结构一起培养，以研究这些组织对哺乳动物成肌分化的影响。由于从携带n-lacZ基因的转基因小鼠中分离出的中胚层组织在肌球蛋白轻链启动子的转录控制下，将其表达限制在横纹肌中，因此通过计数β -半乳糖苷酶阳性细胞的数量，可以轻松准确地定量分化程度。结果表明，轴向结构是促进近轴中胚层分化所必需的，与以往的观察结果一致。然而，轴向结构的影响似乎也可以被靠近近轴向中胚层的背外侧组织所取代。为了阐明这些组织中哪一种具有这种积极作用，我们培养了具有多种相邻结构的近轴中胚层，这些结构要么粘附在中胚层上，要么在体外重组。这些实验结果表明，背外胚层对肌肉发生有积极的影响，但只有在物理上接近它的情况下。相反，侧中胚层延迟了外胚层的积极作用（并且本身没有作用），这表明该组织产生了抑制信号。为了研究轴向结构和背外胚层是否通过共同或不同的途径诱导肌发生，我们解剖了未分节的近轴向中胚层的中间半部分，并与相邻的神经管一起培养。我们还培养了未裂的近轴中胚层的外侧半层和邻近的外胚层。肌生成调节因子myf-5和MyoD的诱导是通过对MyoD和β -半乳糖苷酶抗体的培养细胞进行双重染色来监测的，因为这些组织是从携带针对myf-5基因的n-lacZ的小鼠胚胎中分离出来的，因此myf-5表达细胞可以很容易地通过组织化学或免疫细胞化学染色来识别β -半乳糖苷酶。培养1天后，来自中半部的成肌细胞表达myf-5，但不表达MyoD，而来自外侧半部的成肌细胞表达MyoD，但不表达myf-5。然而，在第二天的体外实验中，大多数肌原细胞都表达了这两种基因产物。这些数据表明，神经管通过myf-5依赖通路激活近轴中胚层内侧的肌发生，而背外胚层通过myod依赖通路激活肌发生。讨论了这些观察结果可能的发育意义，并提出了哺乳动物肌原性决定的模型。
Newly formed somites or unsegmented paraxial mesoderm (UPM) have been cultured either in isolation or with adjacent structures to investigate the influence of these tissues on myogenic differentiation in mammals. The extent of differentiation was easily and accurately quantified by counting the number of beta-galactosidase-positive cells, since mesodermal tissues had been isolated from transgenic mice that carry the n-lacZ gene under the transcriptional control of a myosin light chain promoter, restricting expression to striated muscle. The results obtained showed that axial structures are necessary to promote differentiation of paraxial mesoderm, in agreement with previous observations. However, it also appeared that the influence of axial structures could be replaced by dorsolateral tissues, adjacent to the paraxial mesoderm. To elucidate which of these tissues exerts this positive effect, we cultured the paraxial mesoderm with a variety of adjacent structures, either adherent to the mesoderm or recombined in vitro. The results of these experiments indicated that the dorsal ectoderm exerts a positive influence on myogenesis but only if left in physical proximity to it. In contrast, lateral mesoderm delays the positive effect of the ectoderm (and has no effect on its own) suggesting that this tissue produces an inhibitory signal. To investigate whether axial structures and dorsal ectoderm induce myogenesis through common or separate pathways, we dissected the medial half of the unsegmented paraxial mesoderm and cultured it with the adjacent neural tube. We also cultured the lateral half of the unsegmented paraxial mesoderm with adjacent ectoderm. The induction of the myogenic regulatory factors myf-5 and MyoD was monitored by double staining of cultured cells with antibodies against MyoD and beta-galactosidase since the tissues were isolated from mouse embryos that carry n-lacZ targeted to the myf-5 gene, so that myf-5 expressing cells could be easily identified by either histochemical or immunocytochemical staining for beta-galactosidase. After 1 day in culture myogenic cells from the medial half expressed myf-5 but not MyoD, while myogenic cells from the lateral half expressed MyoD but not myf-5. By the next day in vitro, however, most myogenic cells expressed both gene products. These data suggest that the neural tube activates myogenesis in the medial half of paraxial mesoderm through a myf-5-dependent pathway, while the dorsal ectoderm activates myogenesis through a MyoD-dependent pathway. The possible developmental significance of these observations is discussed and a model of myogenic determination in mammals is proposed.
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影响因子：
4.6
作者：
O. Haub;M. Goldfarb
通讯作者：
O. Haub;M. Goldfarb
体节的生肌规范：轴向结构的诱导。
DOI：
10.1242/dev.120.6.1443
发表时间：
1994
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Buffinger,N;Stockdale,FE
通讯作者：
Stockdale,FE
体节的肌源性规范是由扩散因子介导的。
DOI：
10.1006/dbio.1995.1130
发表时间：
1995
期刊：
Developmental biology.
影响因子：
--
作者：
Buffinger,N;Stockdale,FE
通讯作者：
Stockdale,FE
鹌鹑胚胎体节形态发生过程中三个生肌调节基因的顺序激活。
影响因子：
2.7
作者：
Pownall,ME;EmersonJr,CP
通讯作者：
EmersonJr,CP
通过活体染料标记揭示小鼠胚胎中躯干神经嵴细胞迁移的途径。
DOI：
10.1242/dev.108.4.605
发表时间：
1990
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Serbedzija,GN;Fraser,SE;Bronner-Fraser,M
通讯作者：
Bronner-Fraser,M