EphA4 constitutes a population-specific guidance cue for motor neurons
EphA4 constitutes a population-specific guidance cue for motor neurons
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DOI：
10.1006/dbio.2002.0695
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发表时间：
2002-07-01
影响因子：
2.7
通讯作者：
Krull, CD
中科院分区：
文献类型：
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作者：
Eberhart, J;Swartz, ME;Krull, CD
神经管腹侧的运动神经元将轴突特异性地投射到外周的靶肌肉。尽管许多决定运动神经元细胞命运的转录因子已被鉴定，但对于引导运动轴突到达其正确靶标的机制了解较少。我们发现，EphA4受体酪氨酸激酶的异位表达改变了禽类后肢中特定运动轴突群体的轨迹。在异位EphA4存在的情况下，外侧运动柱（LMC）内侧部分的大多数运动神经元在小腿神经丛水平的背侧神经干中异常地延伸其轴突。运动轴突的这种错误导向并不伴随运动神经元特性、在神经管中的定位模式或脊神经的成束情况的改变。然而，异位的EphA4轴突在后肢基部神经丛的分选过程中确实在路径选择上出现错误。这些结果表明，运动神经元中的EphA4作为一种群体特异性的导向信号，控制其轴突在后肢中的背侧轨迹。（C）2002年爱思唯尔科学（美国）
Motor neurons in the ventral neural tube project axons specifically to their target muscles in the periphery. Although many of the transcription factors that specify motor neuron cell fates have been characterized, less is understood about the mechanisms that guide motor axons to their correct targets. We show that ectopic expression of EphA4 receptor tyrosine kinase alters the trajectories of a specific population of motor axons in the avian hindlimb. Most motor neurons in the medial portion of the lateral motor column (LMC) extend their axons aberrantly in the dorsal nerve trunk at the level of the crural plexus, in the presence of ectopic EphA4. This misrouting of motor axons is not accompanied by alterations in motor neuron identity, settling patterns in the neural tube, or the fasciculation of spinal nerves. However, ectopic EphA4 axons do make errors in pathway selection during sorting in the plexus at the base of the hindlimb. These results suggest that EphA4 in motor neurons acts as a population-specific guidance cue to control the dorsal trajectory of their axons in the hindlimb. (C) 2002 Elsevier Science (USA).