Perea Daniel, Terriente Javier, Díaz-Benjumea Fernando J
Centro de Biología Molecular-Severo Ochoa, Universidad Autónoma-C.S.I.C., Madrid, Spain.
Dev Biol. 2009 Apr 15;328(2):445-55. doi: 10.1016/j.ydbio.2009.02.002. Epub 2009 Feb 13.
Extracellular signalling molecules play many roles in the development of higher organisms. They are used reiteratively in different tissues and stages, but the response of the receiving cells is controlled in a context dependent manner. The pattern of expression of the signalling molecule Wingless/WNT in Drosophila is extraordinarily complex. We have studied the mechanism that controls its expression and function in the outer ring of the Drosophila wing hinge. Our findings indicate that wingless expression is controlled by a dual mechanism: its initial activation requires the product of zinc finger homeodomain 2 and is subsequently repressed by the product of the gene complex elbow/no ocelli. This tight regulation restricts the activation of wingless temporally and spatially. Later in development, wingless expression is maintained by an autoregulatory loop that involves the product of homothorax. We have analyzed the phenotype of a wingless allelic combination that specifically removes the outer ring, and our results show that Wingless is required to promote local proliferation of the wing base cells. Thus, cell proliferation in the proximal-distal axis is controlled by the sequential activation of wingless in the inner ring and the outer ring at different stages of development.
细胞外信号分子在高等生物的发育过程中发挥着多种作用。它们在不同组织和阶段被反复使用，但接收细胞的反应是以一种依赖于上下文的方式受到控制的。果蝇中信号分子无翅/翼状/无翅型（Wingless/WNT）的表达模式极其复杂。我们研究了在果蝇翅铰链外环中控制其表达和功能的机制。我们的研究结果表明，无翅基因的表达受双重机制控制：其初始激活需要锌指同源结构域2的产物，随后被基因复合体肘部/无单眼（elbow/no ocelli）的产物所抑制。这种严格的调控在时间和空间上限制了无翅基因的激活。在发育后期，无翅基因的表达通过一个涉及同胸节（homothorax）产物的自调控环得以维持。我们分析了一个特异性去除外环的无翅等位基因组合的表型，我们的结果表明，无翅基因对于促进翅基部细胞的局部增殖是必需的。因此，在发育的不同阶段，近端 - 远端轴上的细胞增殖由内环和外环中无翅基因的顺序激活所控制。
