Boyle Monica, Nighorn Alan, Thomas John B
Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, PO Box 85800, San Diego, CA 92186, USA.
Development. 2006 May;133(9):1845-54. doi: 10.1242/dev.02353.
The conserved Eph receptors and their Ephrin ligands regulate a number of developmental processes, including axon guidance. In contrast to the large vertebrate Eph/Ephrin family, Drosophila has a single Eph receptor and a single Ephrin ligand, both of which are expressed within the developing nervous system. Here, we show that Eph and Ephrin can act as a functional receptor-ligand pair in vivo. Surprisingly, and in contrast to previous results using RNA-interference techniques, embryos completely lacking Eph function show no obvious axon guidance defects. However, Eph/Ephrin signaling is required for proper development of the mushroom body. In wild type, mushroom body neurons bifurcate and extend distinct branches to different target areas. In Eph mutants, these neurons bifurcate normally, but in many cases the dorsal branch fails to project to its appropriate target area. Thus, Eph/Ephrin signaling acts to guide a subset of mushroom body branches to their correct synaptic targets.
保守的Eph受体及其Ephrin配体调控着许多发育过程，包括轴突导向。与庞大的脊椎动物Eph/Ephrin家族不同，果蝇只有一个Eph受体和一个Ephrin配体，二者均在发育中的神经系统中表达。在此，我们证明Eph和Ephrin在体内可作为功能性受体 - 配体对发挥作用。令人惊讶的是，与先前使用RNA干扰技术得到的结果相反，完全缺乏Eph功能的胚胎未表现出明显的轴突导向缺陷。然而，Eph/Ephrin信号传导对于蕈形体的正常发育是必需的。在野生型中，蕈形体神经元发生分叉并向不同的靶区域延伸出不同的分支。在Eph突变体中，这些神经元正常分叉，但在许多情况下，背侧分支无法投射到其合适的靶区域。因此，Eph/Ephrin信号传导作用于引导蕈形体的一部分分支到达其正确的突触靶标。
