Anatomy of neurogenesis in the early zebrafish brain
Anatomy of neurogenesis in the early zebrafish brain
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DOI：
10.1016/s0165-3806(02)00583-7
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发表时间：
2003-01-13
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影响因子：
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通讯作者：
Wullimann, MF
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文献类型：
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作者：
Mueller, T;Wullimann, MF
胚胎后发育的详细结构通过研究各种前神经碱性螺旋-环-螺旋基因的表达结构域，研究了受精后2天斑马鱼脑中的神经发生（即继发性，而不是原发性）（即neuroD=nrd，neurogenin 1 = ngn 1，Zash-1b）和神经源性基因（即Notch-1a，在原位杂交切片材料的水平上，并与相同年龄的脑切片的PCNA免疫染色进行比较（增殖标志物）或Hu蛋白（早期神经元分化的标志物）。尽管Notch-1a和deltaA结构域都存在于大脑的所有增殖区中，但只有更弥漫和分散的deltaA表达似乎额外延伸到相邻的有丝分裂后灰质中。Zash-1b是第一个在所有增殖性中枢神经区（除眼睛外）表达的无毛鳞片同源基因。ngn 1和nrd基因通常在许多脑区（但不是所有脑区）都以重叠的方式表达，ngn 1更局限于心室增殖区，而nrd更倾向于向外侧延伸。这一事实以及与PCNA和Hu免疫染色的比较表明，很大比例的ngn 1阳性细胞是有丝分裂的，但有些似乎延伸到有丝分裂后的灰质中的nrd域所在。比较PCNA-（增殖的）、nrd-（新测定的）和Hu-阳性（分化的）细胞群的相对程度允许确定给定脑部分的相对成熟状态。与胚胎晚期斑马鱼脑的发现相似，在斑马鱼的腭下区、腹侧视前区、腹侧丘脑和下丘脑中不表达nrd（2 - 5天）。这四个区域也没有ngn 1的表达（除了视前区一个不寻常的外围ngn 1结构域），表明一个不涉及nrd和ngn 1的神经发生网络在那里起作用。我们对整个早期（2 dpf）斑马鱼脑中局部不同的次级神经发生模式和动力学的表征为更专门的功能研究提供了蓝图。(C)2002 Elsevier Science B. V.保留所有权利。
The detailed architecture of postembryonic (i.e. secondary, as opposed to primary) neurogenesis in the zebrafish brain at 2 days postfertilization was investigated by studying expression domains of various proneural basic helix-loop-helix genes (i.e. neuroD=nrd, neurogenin1=ngn1, Zash-1b) and neurogenic genes (i.e. Notch-1a, deltaA) on the level of in situ-hybridized sectioned material and compared with brain sections of the same age immunostained for PCNA (a proliferation marker) or for Hu-proteins (marker for early neuronal differentiation). Whereas both Notch-1a and deltaA domains are present in all proliferative zones of the brain, only the more diffuse and scattered deltaA expression appears to extend additionally into the adjacent postmitotic gray matter. Zash-1b is the first achaete-scute orthologue shown here to be expressed exclusively in all proliferative central nervous zones (except for the eye). The ngn1 and nrd genes are typically both expressed in overlapping fashion in many-but not all-brain regions, with ngn1 being more restricted towards the ventricular proliferative zones and nrd extending more laterally. This fact as well as comparisons with PCNA- and Hu-immunostains indicate that a great proportion of ngn1-positive cells are mitotic, but some appear to extend into the postmitotic gray matter where the nrd-domains lie. A comparison of the relative extents of PCNA- (proliferative), nrd- (freshly determined) and Hu-positive (differentiating) cell populations allows to determine the relative maturation state of a given brain part. Similar to findings in late embryonic amniote brains, expression of nrd is absent (from 2 to 5 days) in the zebrafish subpallium, ventral preoptic region, ventral thalamus and hypothalamus. These four regions are also free of ngn1 expression (with the exception of an unusual peripheral ngn1 domain in the preoptic region), indicating that a neurogenetic network not involving nrd and ngn1 is at work there. Our characterization of locally distinct patterns and dynamics of secondary neurogenesis in the entire early (2 dpf) postembryonic zebratish brain delivers the blueprint for more specialized functional studies. (C) 2002 Elsevier Science B.V. All rights reserved.