Islet1 and Islet2 have equivalent abilities to promote motoneuron formation and to specify motoneuron subtype identity
Islet1 and Islet2 have equivalent abilities to promote motoneuron formation and to specify motoneuron subtype identity
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DOI：
10.1242/dev.02355
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发表时间：
2006-06-01
期刊：
影响因子：
4.6
通讯作者：
Eisen, Judith S.
中科院分区：
文献类型：
--
作者：
Hutchinson, Sarah A.;Eisen, Judith S.
LIM同源盒基因islet1和islet2的表达在斑马鱼初级运动神经元发育过程中受到严格调控。所有初级运动神经元在它们退出细胞周期前后表达胰岛1。到初代运动神经元发生时，特定亚型表达islet1，而其他亚型表达islet2，这表明这两个基因具有不同的功能。在这里，我们发现Islet1是斑马鱼初级运动神经元形成所必需的；在Islet1缺失的情况下，初级运动神经元缺失，某些类型的腹侧中间神经元明显增加。我们还提供证据表明，在初级运动神经元形成过程中，Islet2可以替代Islet1。令人惊讶的是，我们的研究结果表明，尽管Islet1和Islet2具有运动神经元亚型特异性表达模式，但Islet1和Islet2蛋白之间的差异对于不同初级运动神经元亚型的特异性并不重要。因此，初级运动神经元亚型可能是由与islet1和islet2平行或上游作用的因子指定的。
The expression of LIM homeobox genes islet1 and islet2 is tightly regulated during development of zebrafish primary motoneurons. All primary motoneurons express islet1 around the time they exit the cell cycle. By the time primary motoneurons undergo axogenesis, specific subtypes express islet1, whereas other subtypes express islet2, suggesting that these two genes have different functions. Here, we show that Islet1 is required for formation of zebrafish primary motoneurons; in the absence of Islet1, primary motoneurons are missing and there is an apparent increase in some types of ventral interneurons. We also provide evidence that Islet2 can substitute for Islet1 during primary motoneuron formation. Surprisingly, our results demonstrate that despite the motoneuron subtype-specific expression patterns of Islet1 and Islet2, the differences between the Islet1 and Islet2 proteins are not important for specification of the different primary motoneuron subtypes. Thus, primary motoneuron subtypes are likely to be specified by factors that act in parallel to or upstream of islet1 and islet2.