Comparative neuroanatomy of ctenophores: Neural and muscular systems in Euplokamis dunlapae and related species
Comparative neuroanatomy of ctenophores: Neural and muscular systems in Euplokamis dunlapae and related species
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DOI：
10.1002/cne.24770
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发表时间：
2019-10-04
影响因子：
2.5
通讯作者：
Moroz, Leonid L.
中科院分区：
文献类型：
--
作者：
Norekian, Tigran P.;Moroz, Leonid L.
Ctenophora是一个早期分支的基底后生动物谱系，它可能独立于其他动物进化出神经元和肌肉。然而，尽管栉水母之间的深刻的多样性，基础神经解剖数据仅限于两个属的代表。在这里，我们描述了组织的神经肌肉系统在八个栉水母物种的重点是Euplukamis dunlapae的代表血统姐妹所有其他栉水母。Cydippids（Hormiphora hormiphora和Dryodora glandiformis）和裂片（Bolinopsis infundibulum和Mnemiopsis leidyi）被用作参考平台，以涵盖门内的形态和生态多样性。我们发现，即使有很大的环境差异，神经系统的基本组织是保守的栉水母。在所有物种中，我们检测到两个分布式的神经元子系统：上皮下多边形网络和mesogleal元素。尽管如此，每个物种都在神经、肌肉和受体系统方面发展了特定的创新。Euplukamis最显着的特定特征如下：（a）具有巨大轴突的梳状神经。这些神经直接协调快速逃避反应，绕过称为背口感觉器官的中央整合结构。(b)神经过程中的触角沿着行的“盒”提供结构支持和位于横纹肌。(c)穿过中胶层并连接外壁到反口管的放射状肌肉。(d)扁平的肌肉，环绕着每一个骶管。此外，我们检测到一个结构不同的矩形神经网络的Lobata（Mnemiopsis/Bolinopsis），而不是在其他物种的取食叶。所描述的特定谱系的创新可用于未来的单细胞地图集的栉水母和分析的神经元进化的基础后生动物。
Ctenophora is an early-branching basal metazoan lineage, which may have evolved neurons and muscles independently from other animals. However, despite the profound diversity among ctenophores, basal neuroanatomical data are limited to representatives of two genera. Here, we describe the organization of neuromuscular systems in eight ctenophore species focusing on Euplokamis dunlapae-the representative of the lineage sister to all other ctenophores. Cydippids (Hormiphora hormiphora and Dryodora glandiformis) and lobates (Bolinopsis infundibulum and Mnemiopsis leidyi) were used as reference platforms to cover both morphological and ecological diversity within the phylum. We show that even with substantial environmental differences, the basal organization of neural systems is conserved among ctenophores. In all species, we detected two distributed neuronal subsystems: the subepithelial polygonal network and the mesogleal elements. Nevertheless, each species developed specific innovations in neural, muscular, and receptor systems. Most notable Euplokamis-specific features are the following: (a) Comb nerves with giant axons. These nerves directly coordinate the rapid escape response bypassing the central integrative structure known as the aboral sensory organ. (b) Neural processes in tentacles along the rows of "boxes" providing structural support and located under striated muscles. (c) Radial muscles that cross the mesoglea and connect the outer wall to the aboral canal. (d) Flat muscles, encircling each meridional canal. Also, we detected a structurally different rectangular neural network in the feeding lobes of Lobata (Mnemiopsis/Bolinopsis) but not in other species. The described lineage-specific innovations can be used for future single-cell atlases of ctenophores and analyses of neuronal evolution in basal metazoans.