Formation and specification of ventral neuroblasts is controlled by vnd in Drosophila neurogenesis
Formation and specification of ventral neuroblasts is controlled by vnd in Drosophila neurogenesis
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DOI：
10.1101/gad.12.22.3613
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发表时间：
1998-11-15
影响因子：
10.5
通讯作者：
Jiménez, F
中科院分区：
文献类型：
--
作者：
Chu, H;Parras, C;Jiménez, F
在果蝇的神经发育过程中，神经母细胞从每个半节的神经外胚层以五行三列（腹侧、中间和背侧）的典型正交阵列分层。普遍的证据表明，个体神经母细胞的命运是由基因沿背腹轴和前后轴的特定域表达决定的。在这里，我们分析了Vnd（一种NK-2同源结构域蛋白）在神经外胚层和神经母细胞的背腹侧模式中的作用，Vnd最初表达于腹侧中线附近的腹侧神经外胚层。我们发现，在Md null突变体中，大多数腹侧神经母细胞不形成，少数形成的神经母细胞不发展成腹侧细胞，而是发展成中间样细胞。此外，我们证明Vnd影响前膜腹侧簇和神经外胚层的基因表达模式，其在神经母细胞形成中的作用包括但不限于前膜AS-C基因的激活。通过使用GAL4/UAS基因表达系统，我们发现异位Vnd表达可以促进中间和背侧神经母细胞的腹侧样命运，并可以抑制中间和背侧神经外胚层的某些正常特征。我们的结果在果蝇神经外胚层背侧模式的现有证据的背景下进行了讨论。
During Drosophila neural development, neuroblasts delaminate from the neuroectoderm of each hemisegment in a stereotypic orthogonal array of five rows and three columns (ventral, intermediate, and dorsal). Prevailing evidence indicates that the individual neuroblast fate is determined by the domain-specific expression of genes along the dorsoventral and anteroposterior axis. Here, we analyze the role of Vnd, a NK-2 homeodomain protein, expressed initially in the ventral neuroectoderm adjacent to the ventral midline, in the dorsoventral patterning of the neuroectoderm and the neuroblasts. We show that in Md null mutants most ventral neuroblasts do not form and the few that form do not develop ventral fates, but instead develop intermediate-like fates. Furthermore, we demonstrate that Vnd influences the gene expression patterns in the ventral proneural clusters and neuroectoderm, and that its action in neuroblast formation includes, but is not exclusive to the activation of proneural AS-C genes. Through the use of GAL4/UAS gene-expression system we show that ectopic Vnd expression can promote ventral-like fates in intermediate and dorsal neuroblasts and can suppress certain normal characteristics of the intermediate and dorsal neuroectoderm Our results are discussed in the context of the current evidence in dorsoventral patterning in the Drosophila neuroectoderm.