The evolution of early neurogenesis.
The evolution of early neurogenesis.
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DOI：
10.1016/j.devcel.2015.02.004
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发表时间：
2015-02-23
影响因子：
11.8
通讯作者：
Stollewerk A
中科院分区：
文献类型：
--
作者：
Hartenstein V;Stollewerk A
大脑复杂结构的基础是通过胚胎发育期间神经祖细胞的高度定型的增殖和迁移模式奠定的。这个过程，被称为早期神经发生，是由遗传机制，已在许多实验上适合脊椎动物和无脊椎动物模型系统进行了研究。尽管事实上，这些遗传机制是高度保守的，早期神经发生的基本结构方面是不同的模型系统中使用的。脊椎动物的大脑是由神经元层形成的，这些神经元层是由大量嵌入内陷神经上皮（神经管）中的顶端和基底祖细胞产生的。相比之下，果蝇或C.秀丽线虫是从相对少量的不变的祖细胞进化而来的，这些祖细胞以不对称的干细胞样模式分裂以产生固定的谱系。为了更好地理解神经发生，探索这一过程的演变是有益的。使用的分子标记和实验方法所产生的模型系统已经有可能在其他动物中研究早期神经发生，代表了各种不同的分支，我们的审查试图提供一个调查这一机构的工作。我们将神经发生过程分为离散的元素，包括起源，模式，增殖和神经元祖细胞的运动，并比较这些元素（早期神经发生的“工具箱”）在动物中代表不同的分支。在刺胞动物和许多基底两侧动物中，整个胚胎外胚层产生神经前体，其在上皮内分化或分层，并形成弥漫性基底上皮神经网。此外，人们可以区分在大多数基础bilaterians外胚层亚结构域（神经外胚层），保守的调控基因和信号转导途径，含有神经祖细胞在更高的密度，并增加增殖活性的定义。这些神经外胚层祖细胞保持在表面的（少数）基础lophotrochozoans（多毛类）的数据存在;祖细胞成为内在的分层和内陷的组合在基础ecdysozoans（onychophorans）和后口动物（hemichordates，cephalocordates）。在进化程度更高的双侧性动物中，通过增加内陷神经祖细胞（脊椎动物、螯形动物）的体积和/或通过切换到不对称、自我更新的有丝分裂模式（昆虫、甲壳动物、衍生环节动物、脊椎动物）来推进神经增殖，从而实现更大的神经系统。此外，神经祖细胞的分布和增殖模式得到更精确的控制，从而产生具有不变神经元结构的神经系统（环节动物、节肢动物、线虫）。鉴于它们在衍生分支中的有限发生，神经发生的这些方面可能已经独立地进化了多次。
The foundation for the complex architecture of the brain is laid by means of a highly stereotyped pattern of proliferation and migration of neural progenitors during embryonic development. This process, termed early neurogenesis, is controlled by genetic mechanisms that have been studied in a number of experimentally amenable vertebrate and invertebrate model systems. Despite of the fact that many of these genetic mechanisms are highly conserved, fundamental structural aspects of early neurogenesis are different in the model systems used. The vertebrate brain is formed by layers of neurons that arise from large numbers of apical and basal progenitors embedded in an invaginated neuroepithelium (neural tube). By contrast, neurons in Drosophila or C. elegans descend from a relatively small number of invariant progenitors which divide in an asymmetric, stem cell-like pattern to create fixed lineages. In order to achieve a better understanding of neurogenesis it is beneficial to explore the evolution of this process. The use of molecular markers and experimental approaches spawned by the model systems has made it possible to study early neurogenesis in other animals, representing a variety of different clades, and our review attempts to provide a survey of this body of work. We divide the neurogenetic process into discrete elements, including origin, pattern, proliferation, and movement of neuronal progenitors, and compare these elements (the “toolkit” of early neurogenesis) in animals that represent the different clades. In cnidarians and many basal bilaterians the entire embryonic ectoderm produces neural precursors that differentiate within the epithelium or delaminate, and form a diffuse basiepithelial nerve net. In addition, one can distinguish in most basal bilaterians ectodermal subdomains (neuroectoderm), defined by conserved regulatory genes and signaling pathways, that contain neural progenitors at higher density, and with increased proliferatory activity. These neuroectodermal progenitors remain at the surface in the (few) basal lophotrochozoans (polychaetes) for which data exist; progenitors become internalized by a combination of delamination and invagination in basal ecdysozoans (onychophorans) and deuterostomes (hemichordates, cephalochordates). In more evolved bilaterians, larger nervous systems are realized by increasing the volume of invaginated neural progenitors (vertebrates, chelicerates), and/or advancing neural proliferation by switching to a mode of asymmetric, self-renewing mitosis (insects, crustaceans, derived annelids, vertebrates). In addition, the pattern of distribution and proliferation of neural progenitors is more precisely controlled, resulting in nervous systems with invariant neuronal architecture (annelids, arthropods, nematodes). Given their limited occurrence in derived clades, these aspects of neurogenesis have likely evolved independently multiple times.
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影响因子：
4.1
作者：
Brenneis G;Stollewerk A;Scholtz G
通讯作者：
Scholtz G
DOI：
10.1098/rstb.2007.2242
发表时间：
2008-04-27
影响因子：
6.3
作者：
Arendt, Detlev;Denes, Alexandru S.;Tessmar-Raible, Kristin
通讯作者：
Tessmar-Raible, Kristin
影响因子：
16.6
作者：
Demilly, Adrien;Steinmetz, Patrick;Vervoort, Michel
通讯作者：
Vervoort, Michel
影响因子：
64.5
作者：
Denes, Alexandru S.;Jekely, Gaspar;Arendt, Detlev
通讯作者：
Arendt, Detlev
影响因子：
2.8
作者：
Stollewerk A
通讯作者：
Stollewerk A