Delta expression in post-mitotic neurons identifies distinct subsets of adult-specific lineages in drosophila
Delta expression in post-mitotic neurons identifies distinct subsets of adult-specific lineages in drosophila
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DOI：
10.1002/dneu.20308
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发表时间：
2007-01-01
影响因子：
3
通讯作者：
Rand, Mafthew D.
中科院分区：
文献类型：
--
作者：
Cornbrooks, Carson;Bland, Christin;Rand, Mafthew D.
果蝇腹神经索由许多神经元谱系组成，每一个神经元谱系都来源于刻板定位的成神经细胞（NB）。在胚胎阶段，每个NB的独特身份，以及它们的几个神经元后代，其特征在于分子标记物的空间和时间表达模式。这些表达模式在幼虫阶段不被保留，因此成虫特异性谱系的身份仍然模糊不清。最近的克隆分析，使用MARCM已确定24成人特定的血统所产生的胸部NB在幼虫阶段。在这项研究中，我们探讨了Delta蛋白在胚胎后果蝇腹神经索发育中的作用。我们发现Delta表达通过高度富集在新生的有丝分裂后神经元及其轴突束簇中来识别胸神经节的24个成人特异性谱系中的7个。三角洲血统构成的大部分束投射到腹侧神经元，在处理腿部感觉信息的作用一致。使用RNAi靶向敲低神经元中的Delta导致腿部化学感觉反应显著降低和相对不受影响的腿部机械感觉反应。Delta谱系中的Delta RNAi敲低也给出了更弥散的束末端形态，而神经突束的整体寻路不受影响。我们还确定了一个男性特定的三角洲血统的终端腹部神经节，暗示三角洲的性别二态性神经网络的发展中的作用。也可以看到Delta表达神经突接触Notch表达神经胶质的例子，但并不常见于所有Delta谱系。总之，这些数据揭示了Delta表达的基本模式，其指示赋予成人谱系神经元身份的潜在发育程序。(c)2006 Wiley Periodicals，Inc.
The Drosophila ventral nerve cord is comprised of numerous neuronal lineages, each derived from a stereotypically positioned neuroblast (NB). At the embryonic stage the unique identities of each NB, and several of their neuronal progeny, are well characterized by spatial and temporal expression patterns of molecular markers. These patterns of expression are not preserved at the larval stage and thus the identity of adult-specific lineages remains obscure. Recent clonal analysis using MARCM has identified 24 adult-specific lineages arising from thoracic NBs at the larval stage. In this study, we have explored a role for the Delta protein in development of the post-embryonic Drosophila ventral nerve cord. We find that Delta expression identifies 7 of the 24 adult-specific lineages of the thoracic ganglia by being highly enriched in clusters of newly born postmitotic neurons and their neurite bundles. The Delta lineages constitute the majority of bundles projecting to the ventral neuropil, consistent with a role in processing leg sensory information. Targeted knockdown of Delta in neurons using RNAi results in significantly decreased leg chemosensory response and a relatively unaffected leg mechanosensory response. Delta RNAi knockdown in Delta lineages also gives a more diffuse bundle terminal morphology while the overall path-finding of neurite bundles is unaffected. We also identify a male-specific Delta lineage in the terminal abdominal ganglia, implicating a role for Delta in development of sexually dimorphic neural networks. Examples of Delta-expressing neurites contacting Notch-expressing glia are also seen, but are not common to all Delta lineages. Altogether, these data reveal a fundamental pattern of Delta expression that is indicative of an underlying developmental program that confers identity to adult lineage neurons. (c) 2006 Wiley Periodicals, Inc.