CELL AND MATRIX SPECIALIZATIONS OF RHOMBOMERE BOUNDARIES
CELL AND MATRIX SPECIALIZATIONS OF RHOMBOMERE BOUNDARIES
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DOI：
10.1002/aja.1002040308
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发表时间：
1995-11-01
影响因子：
2.5
通讯作者：
LUMSDEN, A
中科院分区：
文献类型：
--
作者：
HEYMAN, I;FAISSNER, A;LUMSDEN, A
后脑部分，菱形球，定义了不同的细胞和分子结构域，为神经和颅骨发育的重要方面提供了基础规划。在这项研究中，进一步的证据表明，菱形球之间的界面，菱形球边界，包含具有特殊特征的细胞和细胞外基质。在菱形球边界的细胞表现出时间和空间上不同的发育重要基因的表达模式。在发育末期，当菱形球出现时，在菱形球边界形成的扇形细胞阵列（构成脑室脊）显示两个基因（Hoxb-1和Krox-20）的表达减少，这两个基因在发育早期在特定菱形球的所有细胞中表达。相反，这些边界细胞显示另一种基因Pax-6的表达增加，该基因在发育早期具有菱形体特异性表达模式。通过在菱形球边界增加抗vimentin抗体的标记，进一步表明边界细胞的特殊身份，表明至少一些边界细胞是放射状胶质细胞或胶质前体。除了不同的细胞特性外，菱形球边界的胞外结构域也是特化的。硫酸软骨素蛋白多糖（CSPG）免疫反应性增强，免疫电镜显示其定位于细胞外间隙。CSPG也富集于消融后再生的边界，或菱形球移植产生的异位边界。我们提出菱形球边界在具有不同分子特征的细胞群之间的界面上形成其特征形态，代表不同的细胞状态。一个特殊的细胞带在界面处发育。边界细胞和细胞外基质都具有在神经发育的后期事件中重要的特征，如轴突引导和细胞迁移。(C) 1995 Wiley-Liss, Inc。
Hindbrain segments, rhombomeres, define distinct cellular and molecular domains which furnish the ground plan for important aspects of neural and cranial development. In this study, further evidence is presented that the interfaces between rhombomeres, rhombomere boundaries, contain both cells and extracellular matrix with specialised characteristics. Cells at rhombomere boundaries show temporally and spatially distinct expression patterns of developmentally important genes. Towards the end of the developmental period when rhombomeres are present, a fan-shaped array of cells at rhombomere boundaries, that constitute the ventricular ridge, shows decreased expression of two genes (Hoxb-1 and Krox-20), which earlier in development were expressed in all cells of specific rhombomeres. In contrast, these boundary cells show increased expression of another gene, Pax-6, which earlier in development has a rhombomere-specific expression pattern. A specialised identity for boundary cells is further suggested by increased labelling with an anti-vimentin antibody at rhombomere boundaries, indicating that at least some boundary cells are radial glia or glial precursors. In addition to distinct cellular properties, the extracellular domain at rhombomere boundaries is also specialised. Chondroitin sulphate proteoglycan (CSPG) immunoreactivity is increased and, as revealed by immuno-electron microscopy, localised to extracellular spaces. CSPG is also enriched in boundaries regenerated after ablation, or boundaries generated ectopically by rhombomere transplantation. We propose that rhombomere boundaries form their characteristic morphology at the interface between groups of cells with differing molecular characteristics, representing different cell states. A specialised band of cells then develops at the interface. Both the boundary cells and extracellular matrix have characteristics which could be important in later events of neural development such as axon guidance and cell migration. (C) 1995 Wiley-Liss, Inc.