Kobayashi Miki, Nakano Masato, Atobe Yoshitoshi, Kadota Tetsuo, Funakoshi Kengo
Department of Neuroanatomy, Yokohama City University School of Medicine, Fukuura, Kanazawa-ku, Japan.
Int J Dev Neurosci. 2011 Nov;29(7):749-56. doi: 10.1016/j.ijdevneu.2011.05.007. Epub 2011 May 30.
The LIM homeodomain protein Islet-1, an embryonic marker for motoneurons in the spinal cord, has been reported to be heterogeneously expressed among motoneuron groups in mouse. In the present study, we examined Islet-1 expression in the thoracic and rostral lumbar spinal cord in prenatal mice. In the thoracic spinal cord at embryonic day 12.5 (E12.5) and E13.5, strong Islet-1 immunoreactivity was observed in the lateral group of the ventral horn, whereas weaker immunoreactivity was observed in the ventral group. Strong Islet-1 immunoreactivity was also observed in the intermediolateral area and more medial part of the intermediate zone. In the rostral lumbar spinal cord at E12.5 and E13.5, strong Islet-1 immunoreactivity was observed in the lateral group of the ventral horn, and in the intermediolateral nucleus, whereas weaker immunoreactivity was observed in the ventral, and dorsolateral groups. At E14.5, the number of Islet-1 immunoreactive neurons was reduced in the spinal cord, but the distribution pattern was similar to that at E12.5 and E13.5. At E15.5, Islet-1 immunoreactivity was almost completely confined to the intermediolateral area. Some weakly immunoreactive neurons were observed in the ventral horn. The findings of the present study indicated that Islet-1 expression at embryonic stages differs among the motoneuron groups in the thoracic and rostral lumbar spinal cord.
LIM 同源结构域蛋白胰岛-1 是脊髓运动神经元的一种胚胎标志物，据报道在小鼠的运动神经元群体中呈异质性表达。在本研究中，我们检测了产前小鼠胸段和腰段上段脊髓中胰岛-1 的表达情况。在胚胎第 12.5 天（E12.5）和 E13.5 的胸段脊髓中，在腹角外侧组观察到强胰岛-1 免疫反应性，而在腹侧组观察到较弱的免疫反应性。在中间外侧区和中间带更内侧部分也观察到强胰岛-1 免疫反应性。在 E12.5 和 E13.5 的腰段上段脊髓中，在腹角外侧组和中间外侧核观察到强胰岛-1 免疫反应性，而在腹侧组和背外侧组观察到较弱的免疫反应性。在 E14.5 时，脊髓中胰岛-1 免疫反应性神经元数量减少，但分布模式与 E12.5 和 E13.5 时相似。在 E15.5 时，胰岛-1 免疫反应性几乎完全局限于中间外侧区。在腹角观察到一些弱免疫反应性神经元。本研究结果表明，胚胎期胸段和腰段上段脊髓运动神经元群体中胰岛-1 的表达存在差异。
