Embryonic motor axon development in the severe SMA mouse
Embryonic motor axon development in the severe SMA mouse
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DOI：
10.1093/hmg/ddn189
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发表时间：
2008-09-15
影响因子：
3.5
通讯作者：
Burghes, Arthur H. M.
中科院分区：
文献类型：
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作者：
McGovern, Vicki L.;Gavrilina, Tatiana O.;Burghes, Arthur H. M.
脊髓性肌萎缩症（SMA）是由运动神经元存活蛋白（SMN）水平降低引起的。以前，培养的SMA运动神经元显示生长锥大小和轴突长度减少。此外，在斑马鱼中SMN的减少导致运动神经元轴突的截断和分支。在这项研究中，运动神经元标记的绿色荧光蛋白（GFP）在SMA小鼠从胚胎第10.5天到出生后第2天检查。SMA运动轴突在任何发育阶段的轴突形成或生长均无缺陷。然而，在胚胎SMA小鼠中检测到缺乏运动轴突输入的突触显著增加。因此，SMA小鼠中最早可检测到的形态学缺陷之一是运动轴突丧失突触占据。这表明在严重的SMA小鼠中，运动轴突形成没有缺陷，然而，我们发现胚胎发育中去神经支配的证据。
Spinal muscular atrophy (SMA) is caused by reduced levels of survival motor neuron (SMN) protein. Previously, cultured SMA motor neurons showed reduced growth cone size and axonal length. Furthermore, reduction of SMN in zebrafish resulted in truncation followed by branching of motor neuron axons. In this study, motor neurons labeled with green fluorescent protein (GFP) were examined in SMA mice from embryonic day 10.5 to postnatal day 2. SMA motor axons showed no defect in axonal formation or outgrowth at any stage of development. However, a significant increase in synapses lacking motor axon input was detected in embryonic SMA mice. Therefore, one of the earliest detectable morphological defects in the SMA mice is the loss of synapse occupation by motor axons. This indicates that in severe SMA mice there are no defects in motor axon formation however, we find evidence of denervation in embryogenesis.