Kasioulis Ioannis, Storey Kate G
Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, UK.
Int J Dev Biol. 2018;62(1-2-3):167-175. doi: 10.1387/ijdb.170268ks.
Signalling pathways that regulate neural progenitor proliferation and neuronal differentiation have been identified. However, we know much less about how transduction of such signals is regulated within neuroepithelial cells to direct cell fate choice during mitosis and subsequent neuronal differentiation. Here we review recent advances in the experimentally amenable chick embryo, which reveal that this involves association of signalling pathway components with cell biological entities, including mitotic centrosomes and ciliary structures. This includes changing centrosomal localization of protein kinase A, which regulates Sonic hedgehog signalling and so neural progenitor status, and Mindbomb1, a mediator of Notch ligand activation, which promotes Notch signalling in neighbouring cells, and so is active in presumptive neurons. We further review cell biological events that underlie the later step of neuronal delamination, during which a newborn neuron detaches from its neighbouring cells and undergoes a process known as apical abscission. This involves inter-dependent actin and microtubule dynamics and includes dissociation of the centrosome from the ciliary membrane, which potentially alters the signalling repertoire of this now post-mitotic cell. Open questions and future directions are discussed along with technological advances which improve accuracy of gene manipulation, monitoring of protein dynamics and quantification of cell biological processes in living tissues.
调节神经祖细胞增殖和神经元分化的信号通路已被确定。然而，对于这些信号在神经上皮细胞内如何转导以在有丝分裂期间指导细胞命运选择以及随后的神经元分化，我们了解得还很少。在这里，我们回顾了易于实验操作的鸡胚的最新进展，这些进展表明这涉及信号通路成分与细胞生物学实体的关联，包括有丝分裂中心体和纤毛结构。这包括改变蛋白激酶A的中心体定位，其调节音猬因子信号传导从而影响神经祖细胞状态，以及Mindbomb1，一种Notch配体激活的介质，它在相邻细胞中促进Notch信号传导，因此在假定的神经元中活跃。我们进一步回顾了神经元脱层后期步骤所基于的细胞生物学事件，在此过程中，一个新生神经元与其相邻细胞分离并经历一个称为顶端脱离的过程。这涉及相互依赖的肌动蛋白和微管动力学，包括中心体从纤毛膜上解离，这可能会改变这个现在已完成有丝分裂的细胞的信号传导模式。我们讨论了开放问题和未来方向，以及提高基因操作准确性、监测蛋白质动力学和定量活组织中细胞生物学过程的技术进展。
