Division of Genetics, Boston Children's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
Division of Genetics, Boston Children's Hospital, Boston, MA 02115, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
Cell Rep. 2016 Jun 7;15(10):2109-2117. doi: 10.1016/j.celrep.2016.05.003. Epub 2016 May 26.
Simple cell-cell interactions can give rise to complex cellular patterns. For example, neurons of the same type can interact to create a complex patchwork of non-overlapping dendrite arbors, a pattern known as dendrite tiling. Dendrite tiling often involves mutual repulsion between neighboring neurons. While dendrite tiling is found across nervous systems, the nematode Caenorhabditis elegans has a relatively simple nervous system with few opportunities for tiling. Here, we show that genetic duplication of a single neuron, PVD, is sufficient to create dendrite tiling among the resulting ectopic neurons. We use laser ablation to show that this tiling is mediated by mutual repulsion between neighbors. Furthermore, we find that tiling requires a repulsion signal (UNC-6/Netrin and its receptors UNC-40/DCC and UNC-5) that normally patterns the PVD dendrite arbor. These results demonstrate that an apparently complex cellular pattern can emerge in a simple nervous system merely by increasing neuron number.
简单的细胞间相互作用可以产生复杂的细胞模式。例如，相同类型的神经元可以相互作用，形成一个复杂的不重叠树突分支图案，这种模式被称为树突平铺。树突平铺通常涉及相邻神经元之间的相互排斥。虽然树突平铺在神经系统中都有发现，但线虫秀丽隐杆线虫的神经系统相对简单，平铺的机会较少。在这里，我们发现单个神经元 PVD 的基因复制足以在产生的异位神经元中产生树突平铺。我们使用激光消融来表明这种平铺是由相邻神经元之间的相互排斥介导的。此外，我们发现平铺需要一个排斥信号（UNC-6/Netrin 及其受体 UNC-40/DCC 和 UNC-5），该信号通常对 PVD 树突分支进行模式化。这些结果表明，一个明显复杂的细胞模式可以仅仅通过增加神经元数量出现在一个简单的神经系统中。
