Embryonic neurogenesis in Pseudopallene sp. (Arthropoda, Pycnogonida) includes two subsequent phases with similarities to different arthropod groups.
Embryonic neurogenesis in Pseudopallene sp. (Arthropoda, Pycnogonida) includes two subsequent phases with similarities to different arthropod groups.
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DOI：
10.1186/2041-9139-4-32
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发表时间：
2013-11-29
期刊：
影响因子：
4.1
通讯作者：
Scholtz G
中科院分区：
文献类型：
--
作者：
Brenneis G;Stollewerk A;Scholtz G
对早期神经发生的研究对节肢动物系统发育关系的讨论产生了相当大的影响，揭示了主要谱系之间惊人的相似性和差异。在六足动物和甲壳类动物中，神经发生涉及神经母细胞，一种神经干细胞。在每个半节段中，一组神经母细胞通过重复的不对称和内部定向分裂产生神经细胞。在真螯肢动物和多足动物中，神经发生缺乏神经干细胞，其特点是神经细胞群从神经外胚层的固定位点直接迁移。因此，迄今为止，神经干细胞被认为是四足动物（六足动物+甲壳动物）的进化新事物。为了进一步检验这一假设，我们研究了海蜘蛛的神经发生，海蜘蛛是一群与真螯肢动物有密切亲缘关系的海洋节肢动物。我们研究了 Pseudopallen sp. 胚胎发育过程中的神经发生。 （Callipallenidae），使用荧光组织化学染色和免疫标记。胚胎神经发生有两个阶段。第一阶段与真螯动物和多足动物有显着的相似之处。这些包括 i) 神经外胚层缺乏形态上不同的细胞类型； ii) 形成可瞬时识别的、按定型排列的细胞内化位点； iii) 主要有丝分裂后神经节细胞的迁移； iv) 限制切向细胞增殖至顶端细胞层。然而，在第二阶段，每个半神经节中央内陷的形成伴随着顶端神经干细胞的分化。后者体积增大，表现出高有丝分裂活性和不对称分裂模式。神经节细胞分化后数量显着增加。在神经干细胞的直接基底层，发现了另一种类型的中间神经前体细胞。假苍白球菌的胚胎神经发生。结合了迄今为止在不同节肢动物类群中分别描述的中枢神经系统发育特征。 pycnogonid 神经发生的两阶段特征要求对其他非模型节肢动物在整个神经发生过程中进行彻底的重新研究。根据目前可用的数据，pycnogonid 神经干细胞和四康神经母细胞的共同起源仍未解决。为了承认这一点，我们提出了关于节肢动物神经发生进化的两种可能的情况，其中多足纲在解决这个问题中发挥着关键作用。
Studies on early neurogenesis have had considerable impact on the discussion of the phylogenetic relationships of arthropods, having revealed striking similarities and differences between the major lineages. In Hexapoda and crustaceans, neurogenesis involves the neuroblast, a type of neural stem cell. In each hemi-segment, a set of neuroblasts produces neural cells by repeated asymmetrical and interiorly directed divisions. In Euchelicerata and Myriapoda, neurogenesis lacks neural stem cells, featuring instead direct immigration of neural cell groups from fixed sites in the neuroectoderm. Accordingly, neural stem cells were hitherto assumed to be an evolutionary novelty of the Tetraconata (Hexapoda + crustaceans). To further test this hypothesis, we investigated neurogenesis in Pycnogonida, or sea spiders, a group of marine arthropods with close affinities to euchelicerates. We studied neurogenesis during embryonic development of Pseudopallene sp. (Callipallenidae), using fluorescent histochemical staining and immunolabelling. Embryonic neurogenesis has two phases. The first phase shows notable similarities to euchelicerates and myriapods. These include i) the lack of morphologically different cell types in the neuroectoderm; ii) the formation of transiently identifiable, stereotypically arranged cell internalization sites; iii) immigration of predominantly post-mitotic ganglion cells; and iv) restriction of tangentially oriented cell proliferation to the apical cell layer. However, in the second phase, the formation of a central invagination in each hemi-neuromere is accompanied by the differentiation of apical neural stem cells. The latter grow in size, show high mitotic activity and an asymmetrical division mode. A marked increase of ganglion cell numbers follows their differentiation. Directly basal to the neural stem cells, an additional type of intermediate neural precursor is found. Embryonic neurogenesis of Pseudopallene sp. combines features of central nervous system development that have been hitherto described separately in different arthropod taxa. The two-phase character of pycnogonid neurogenesis calls for a thorough reinvestigation of other non-model arthropods over the entire course of neurogenesis. With the currently available data, a common origin of pycnogonid neural stem cells and tetraconate neuroblasts remains unresolved. To acknowledge this, we present two possible scenarios on the evolution of arthropod neurogenesis, whereby Myriapoda play a key role in the resolution of this issue.
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影响因子：
64.5
作者：
Creppe, Catherine;Malinouskaya, Lina;Nguyen, Laurent
通讯作者：
Nguyen, Laurent
影响因子：
2.9
作者：
Brenneis, Georg;Ungerer, Petra;Scholtz, Gerhard
通讯作者：
Scholtz, Gerhard
影响因子：
2.7
作者：
Brena, Carlo;Akam, Michael
通讯作者：
Akam, Michael
影响因子：
4.1
作者：
Bourlat, Sarah J.;Nielsen, Claus;Telford, Maximilian J.
通讯作者：
Telford, Maximilian J.
影响因子：
9.2
作者：
Cook, CE;Smith, ML;Akam, M
通讯作者：
Akam, M