Morphogenetic mechanisms forming the notochord rod: The turgor pressure‐sheath strength model
Morphogenetic mechanisms forming the notochord rod: The turgor pressure‐sheath strength model
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DOI：
10.1111/dgd.12665
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发表时间：
2020-04
期刊：
影响因子：
4.6
通讯作者：
Yuuri Yasuoka
中科院分区：
文献类型：
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作者：
Yuuri Yasuoka
脊索是脊索动物的特征。在脊椎动物和被囊动物的脊索形成过程中，脊索细胞显示动态的形态发生运动，称为会聚延伸，其中细胞插入并在背中线对齐。然而，在头索动物中，脊索动物的最基部的组，脊索形成没有会聚延伸。它只是由背中线的中胚层细胞发育而来。这表明脊索细胞的会聚延伸运动是嗅觉器官（脊椎动物+被囊动物）的共同祖先中次要获得的发育属性，并且脊索动物祖先在独立于细胞运动的形态发生机制的基础上创新了脊索。因此，这篇评论的重点是脊索细胞，这已经很好地研究了爪蛙，斑马鱼和被囊动物的生物学特征。脊索细胞的属性，如空泡化、膜运输、细胞外基质形成和凋亡，可以根据两种性质来理解：空泡的膨压和脊索鞘的强度。为了保持脊索的直杆状结构，这些参数必须平衡。在未来，膨压鞘强度模型，在这篇评论中提出，将根据定量分子数据和数学模拟进行检查，阐明脊索的进化起源。
The notochord is a defining feature of chordates. During notochord formation in vertebrates and tunicates, notochord cells display dynamic morphogenetic movement, called convergent extension, in which cells intercalate and align at the dorsal midline. However, in cephalochordates, the most basal group of chordates, the notochord is formed without convergent extension. It is simply developed from mesodermal cells at the dorsal midline. This suggests that convergent extension movement of notochord cells is a secondarily acquired developmental attribute in the common ancestor of olfactores (vertebrates + tunicates), and that the chordate ancestor innovated the notochord upon a foundation of morphogenetic mechanisms independent of cell movement. Therefore, this review focuses on biological features specific to notochord cells, which have been well studied using clawed frogs, zebrafish, and tunicates. Attributes of notochord cells, such as vacuolation, membrane trafficking, extracellular matrix formation, and apoptosis, can be understood in terms of two properties: turgor pressure of vacuoles and strength of the notochord sheath. To maintain the straight rod‐like structure of the notochord, these parameters must be counterbalanced. In the future, the turgor pressure‐sheath strength model, proposed in this review, will be examined in light of quantitative molecular data and mathematical simulations, illuminating the evolutionary origin of the notochord.