Ascidians as excellent chordate models for studying the development of the nervous system during embryogenesis and metamorphosis.
Ascidians as excellent chordate models for studying the development of the nervous system during embryogenesis and metamorphosis.
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海鞘是研究胚胎发生和变态过程中神经系统发育的优秀脊索动物模型。
DOI：
10.1111/j.1440-169x.2012.01343.x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Yasunori Sasakura
中科院分区：
文献类型：
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作者：
柿澤茂行;鎌形洋一;Yasunori Sasakura
脊索海鞘游动幼体具有与脊椎动物相似的背侧中空中枢神经系统。尽管具有同源性，海鞘CNS由可计数数量的细胞组成。海鞘简单的神经系统为研究脊索动物神经系统的发育机制提供了一个良好的实验系统。在卵裂阶段，由海鞘CNS组成的细胞的神经命运以自主和非自主的方式确定。海鞘神经板执行类似于脊椎动物神经管形成的神经管闭合的形态发生运动。神经形成后，中枢神经系统分为五个不同的区域，其同源性的脊椎动物中枢神经系统的区域进行了讨论。海鞘在幼虫阶段之后，会经历一次变态，变成无柄的成虫。海鞘的变态过程完成迅速，是观察变态过程中中枢神经系统重组的良好实验系统。最近的研究表明，幼虫中枢神经系统的主要部分仍然在变态后形成成年中枢神经系统。与这种保守的中枢神经系统重组方式相反，大多数幼虫神经元在变态过程中消失。中枢神经系统中的幼虫胶质细胞是成年中枢神经系统形成的主要来源，并且部分胶质细胞产生成年神经元。
The swimming larvae of the chordate ascidians possess a dorsal hollowed central nervous system (CNS), which is homologous to that of vertebrates. Despite the homology, the ascidian CNS consists of a countable number of cells. The simple nervous system of ascidians provides an excellent experimental system to study the developmental mechanisms of the chordate nervous system. The neural fate of the cells consisting of the ascidian CNS is determined in both autonomous and non‐autonomous fashion during the cleavage stage. The ascidian neural plate performs the morphogenetic movement of neural tube closure that resembles that in vertebrate neural tube formation. Following neurulation, the CNS is separated into five distinct regions, whose homology with the regions of vertebrate CNS has been discussed. Following their larval stage, ascidians undergo a metamorphosis and become sessile adults. The metamorphosis is completed quickly, and therefore the metamorphosis of ascidians is a good experimental system to observe the reorganization of the CNS during metamorphosis. A recent study has shown that the major parts of the larval CNS remain after the metamorphosis to form the adult CNS. In contrast to such a conserved manner of CNS reorganization, most larval neurons disappear during metamorphosis. The larval glial cells in the CNS are the major source for the formation of the adult CNS, and some of the glial cells produce adult neurons.