Development of the nervous system in the early hatching larvae of the ctenophore Mnemiopsis leidyi
Development of the nervous system in the early hatching larvae of the ctenophore Mnemiopsis leidyi
复制标题
DOI：
10.1002/jmor.21398
复制
发表时间：
2021-07-26
影响因子：
1.5
通讯作者：
Moroz, Leonid L.
中科院分区：
文献类型：
--
作者：
Norekian, Tigran P.;Moroz, Leonid L.
栉水母是早期分支的基底后生动物谱系的后代，其可能独立于其他动物进化出神经元和肌肉。拟栉水母是重要的参考种之一。然而，对其神经肌肉组织知之甚少。在这里，我们映射和跟踪的早期孵化cydippid幼虫的神经和肌肉元素的发展，以及成人Mnemiopsis leidyi。拟记忆肌神经肌肉系统的整体发育与Bachei侧臂肌非常相似，尽管在拟记忆肌中整个过程发生得更快。孵化后立即观察上皮下神经细胞。这个群体由十几个分离的单个神经元组成，这些神经元具有短的神经突。在大约2天内，当它们的神经突明显变长并连接到它们的邻居时，它们开始形成一个典型的多边形上皮下网络。中胶层神经元突出的所有研究的成年栉水母中没有检测到的Mnemiopsis幼虫，但明确标记密切相关的Lobata种Bolinopsis漏斗。孵化的幼虫也有推定的机械感受器长静纤毛和大约二十几个肌肉细胞。在成年拟记忆鱼中，摄食叶和耳廓包含两个不同的神经元和神经系综群体，这在其他栉水母谱系中没有观察到，可能代表了分支Lobata及其生活方式的复杂神经元创新特征。
Ctenophores are descendants of an early branching basal metazoan lineage, which may have evolved neurons and muscles independently from other animals. Mnemiopsis is one of the important reference ctenophore species. However, little is known about its neuromuscular organization. Here, we mapped and tracked the development of the neural and muscular elements in the early hatching cydippid larvae, as well as adult Mnemiopsis leidyi. The overall development of the neuromuscular system in Mnemiopsis was very similar to Pleurobrachia bachei, although in Mnemiopsis the entire process occurred significantly faster. The subepithelial neural cells were observed immediately after hatching. This population consisted of a dozen of separated individual neurons with short neurites. In about 2 days, when their neurites grew significantly longer and connected to their neighbors, they began to form a canonical polygonal subepithelial network. Mesogleal neural elements prominent in all studied adult ctenophores were not detectable in Mnemiopsis larvae but were clearly labeled in closely related Lobata species Bolinopsis infundibulum. Hatched larvae also had putative mechanoreceptors with long stereocilia and approximately two dozen muscle cells. In adult Mnemiopsis, the feeding lobes and auricles contained two distinct populations of neurons and neural ensembles that were not observed in other ctenophore lineages and likely represented elaborate neuronal innovations characteristic for the clade Lobata and their lifestyles.