Hutson Lara D, Chien Chi Bin
Department of Neurobiology and Anatomy, University of Utah Medical Center, 20 North 1900 East, Salt Lake City, UT 84132, USA.
Neuron. 2002 Jan 17;33(2):205-17. doi: 10.1016/s0896-6273(01)00579-7.
To address how the highly stereotyped retinotectal pathway develops in zebrafish, we used fixed-tissue and time-lapse imaging to analyze morphology and behavior of wild-type and mutant retinal growth cones. Wild-type growth cones increase in complexity and pause at the midline. Intriguingly, they make occasional ipsilateral projections and other pathfinding errors, which are always eventually corrected. In the astray/robo2 mutant, growth cones are larger and more complex than wild-type. astray axons make midline errors not seen in wild-type, as well as errors both before and after the midline. astray errors are rarely corrected. The presumed Robo ligands Slit2 and Slit3 are expressed near the pathway in patterns consistent with their mediating pathfinding through Robo2. Thus, Robo2 does not control midline crossing of retinal axons, but rather shapes their pathway, by both preventing and correcting pathfinding errors.
为了研究高度定型的视网膜-脑顶盖通路在斑马鱼中是如何发育的，我们使用固定组织和延时成像技术来分析野生型和突变型视网膜生长锥的形态和行为。野生型生长锥的复杂性增加，并在中线处暂停。有趣的是，它们偶尔会做出同侧投射和其他路径寻找错误，但最终总会得到纠正。在astray/robo2突变体中，生长锥比野生型更大且更复杂。astray轴突会出现野生型中未见到的中线错误，以及中线之前和之后的错误。astray错误很少得到纠正。推测的Robo配体Slit2和Slit3在该通路附近表达，其模式与它们通过Robo2介导路径寻找一致。因此，Robo2并不控制视网膜轴突的中线交叉，而是通过预防和纠正路径寻找错误来塑造它们的通路。
