Appel B, Korzh V, Glasgow E, Thor S, Edlund T, Dawid I B, Eisen J S
Institute of Neuroscience, University of Oregon, Eugene 97403, USA.
Development. 1995 Dec;121(12):4117-25. doi: 10.1242/dev.121.12.4117.
In zebrafish, individual primary motoneurons can be uniquely identified by their characteristic cell body positions and axonal projection patterns. The fate of individual primary motoneurons remains plastic until just prior to axogenesis when they become committed to particular identities. We find that distinct primary motoneurons express particular combinations of LIM homeobox genes. Expression precedes axogenesis as well as commitment, suggesting that LIM homeobox genes may contribute to the specification of motoneuronal fates. By transplanting them to new spinal cord positions, we demonstrate that primary motoneurons can initiate a new program of LIM homeobox gene expression, as well as the morphological features appropriate for the new position. We conclude that the patterned distribution of different primary motoneuronal types within the zebrafish spinal cord follows the patterned expression of LIM homeobox genes, and that this reflects a highly resolved system of positional information controlling gene transcription.
在斑马鱼中，单个初级运动神经元可通过其独特的细胞体位置和轴突投射模式来唯一识别。单个初级运动神经元的命运在轴突发生之前一直具有可塑性，直到它们确定为特定的身份。我们发现不同的初级运动神经元表达特定组合的LIM同源框基因。这种表达在轴突发生和命运确定之前就已出现，这表明LIM同源框基因可能有助于运动神经元命运的特化。通过将它们移植到新的脊髓位置，我们证明初级运动神经元可以启动一个新的LIM同源框基因表达程序，以及适合新位置的形态特征。我们得出结论，斑马鱼脊髓内不同初级运动神经元类型的模式分布遵循LIM同源框基因的模式表达，这反映了一个高度解析的控制基因转录的位置信息系统。
