Bang A G, Goulding M D
Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA.
Curr Opin Neurobiol. 1996 Feb;6(1):25-32. doi: 10.1016/s0959-4388(96)80005-5.
Evidence that region- and cell-type-specific transcription factors regulate morphogenesis and differentiation of the vertebrate nervous system comes from numerous studies, including descriptions of discrete patterns of expression during neural development and analysis of mutant phenotypes. Recently published works provide insights into the roles of vertebrate transcription factors in regulating the generation of neural precursors, regionalization of the nervous system, and subsequent differentiation of specific cell types within these regions. For instance, misexpression studies in Xenopus embryos show that the newly isolated basic helix-loop-helix protein NeuroD is able to promote neurogenesis, whereas analysis of mouse embryos mutant for the homeobox gene En-1 demonstrates that this transcription factor is required for proper development of the midbrain-hindbrain region. A recent study in chick shows that the combinatorial expression of Islet-1, Lim-1, and two other LIM homeobox genes, Islet-2 and Lim-3, defines subclasses of motor neurons in the spinal cord, supporting a model where combinatorial repertoires of transcription factors may act to generate diverse cell types.
区域和细胞类型特异性转录因子调控脊椎动物神经系统形态发生和分化的证据来自众多研究，包括对神经发育过程中离散表达模式的描述以及突变体表型分析。最近发表的研究成果深入揭示了脊椎动物转录因子在调节神经前体生成、神经系统区域化以及这些区域内特定细胞类型后续分化中的作用。例如，对非洲爪蟾胚胎的异位表达研究表明，新分离出的碱性螺旋-环-螺旋蛋白NeuroD能够促进神经发生，而对同源框基因En-1突变的小鼠胚胎分析表明，该转录因子是中脑-后脑区域正常发育所必需的。最近一项对鸡的研究表明，Islet-1、Lim-1以及另外两个LIM同源框基因Islet-2和Lim-3的组合表达定义了脊髓运动神经元的亚类，支持了一种模型，即转录因子的组合库可能作用于产生多种细胞类型。
