Masai I, Stemple D L, Okamoto H, Wilson S W
Laboratory for Developmental Gene Regulation, Brain Science Institute, RIKEN, Saitama, Japan.
Neuron. 2000 Aug;27(2):251-63. doi: 10.1016/s0896-6273(00)00034-9.
In zebrafish, neuronal differentiation progresses across the retina in a pattern that is reminiscent of the neurogenic wave that sweeps across the developing eye in Drosophila. We show that expression of a zebrafish homolog of Drosophila atonal, ath5, sweeps across the eye predicting the wave of neuronal differentiation. By analyzing the regulation of ath5 expression, we have elucidated the mechanisms that regulate initiation and spread of neurogenesis in the retina. ath5 expression is lost in Nodal pathway mutant embryos lacking axial tissues that include the prechordal plate. A likely role for axial tissue is to induce optic stalk cells that subsequently regulate ath5 expression. Our results suggest that a series of inductive events, initiated from the prechordal plate and progressing from the optic stalks, regulates the spread of neuronal differentiation across the zebrafish retina.
在斑马鱼中，神经元分化以一种模式在视网膜中进行，这种模式让人联想到在果蝇发育中的眼睛中横扫而过的神经发生波。我们发现，果蝇无调性基因（atonal）的斑马鱼同源基因ath5的表达在眼睛中横扫而过，预测了神经元分化的波。通过分析ath5表达的调控，我们阐明了调节视网膜神经发生起始和扩散的机制。在缺乏包括前索板在内的轴向组织的Nodal信号通路突变胚胎中，ath5表达缺失。轴向组织的一个可能作用是诱导视柄细胞，这些细胞随后调节ath5的表达。我们的结果表明，一系列从胚胎前索板起始并从视柄向前推进的诱导事件，调节着斑马鱼视网膜中神经元分化的扩散。
