Vein-positioning in the Drosophila wing in response to Hh;: new roles of Notch signaling
Vein-positioning in the Drosophila wing in response to Hh;: new roles of Notch signaling
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DOI：
10.1016/s0925-4773(03)00041-8
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发表时间：
2003-05-01
影响因子：
2.6
通讯作者：
Vincent, A
中科院分区：
文献类型：
--
作者：
Crozatier, M;Glise, B;Vincent, A
果蝇翅膀是研究发育模式产生的经典模型。以往的研究表明，静脉原基的形式之间的边界离散部门的基因表达沿着前后（A/P）轴在幼虫翅成虫盘。观察到脉标记菱形（rho）在较宽的脉感受态结构域的中心表达，导致提出首先形成窄脉原基，并产生次级短程信号，激活邻近细胞中的原脉基因（参见Curr. Opin. Genet. Dev. 10（2000）393）。在这里，我们研究了中央L3和L4静脉相对于Collier（Col）表达的限制是如何定位的，Collier是一种在机翼A/P组织者中激活的剂量依赖性Hedgehog（Hh）靶标。我们发现，rho的表达首先激活广泛的域附近的Col-expressing细胞，其次限制在这些域的中心。这种依赖于Notch（N）信号传导的限制使L3和L4静脉原基偏离Col表达的边界。还需要N活性通过局部拮抗Hh激活来固定Col表达的前限，从而相对于A/P室边界精确定位L3静脉原基。使用Nts突变体的实验进一步表明，N的这两种活性可以在时间上解耦。总之，这些观察结果突出了新的作用，N在拓扑连接的位置静脉prepattern基因表达。(C)2003爱思唯尔科学爱尔兰有限公司保留所有权利。
The Drosophila wing is a classical model for studying the generation of developmental patterns. Previous studies have suggested that vein primordia form at boundaries between discrete sectors of gene expression along the antero-posterior (A/P) axis in the larval wing imaginal disc. Observation that the vein marker rhomboid (rho) is expressed at the centre of wider vein-competent domains led to propose that narrow vein primordia form first, and produce secondary short-range signals activating provein genes in neighbouring cells (see Curr. Opin. Genet. Dev. 10 (2000) 393). Here, we examined how the central L3 and L4 veins are positioned relative to the limits of expression of Collier (Col), a dose-dependent Hedgehog (Hh) target activated in the wing A/P organiser. We found that rho expression is first activated in broad domains adjacent to Col-expressing cells and secondarily restricted to the centre of these domains. This restriction which depends upon Notch (N) signaling sets the L3 and L4 vein primordia off the boundaries of Col expression. N activity is also required to fix the anterior limit of Col expression by locally antagonising Hh activation, thus precisely positioning the L3 vein primordium relative to the A/P compartment boundary. Experiments using Nts mutants further indicated that these two activities of N could be temporally uncoupled. Together, these observations highlight new roles of N in topologically linking the position of veins to prepattern gene expression. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.