Gieseler K, Wilder E, Mariol M C, Buratovitch M, Bérenger H, Graba Y, Pradel J
Laboratoire de Génétique et Physiologie du Développement, Institut de Biologie du Développement de Marseille, CNRS/INSERM/Université de la Méditerranée, Parc Scientifique de Luminy, Case 907, Marseille Cedex 9, 13288, France.
Dev Biol. 2001 Apr 15;232(2):339-50. doi: 10.1006/dbio.2001.0184.
Wnt genes encode evolutionarily conserved secreted proteins that provide critical functions during development. Although Wnt proteins share highly conserved features, they also show sequence divergence, which almost certainly contributes to the variety of their signaling activities. We previously reported that DWnt4 and wingless (wg), two divergent clustered Wnt genes, can have either antagonist or distinct functions during Drosophila embryogenesis. Here we provide evidence that both genes can elicit similar cellular responses during imaginal development. Ectopic expression of DWnt4 along the anterior/posterior (A/P) boundary of imaginal discs alters morphogenesis of adult appendages. In the wing disc, DWnt4 phenocopies ectopic Wg activity by inducing notum to wing transformation, suggesting similar signaling capabilities of both molecules. In support of this, we demonstrate that DWnt4 can rescue wg loss-of-function phenotypes in the antenna and haltere and is able to substitute for Wg in wing field specification. We also show that both genes are transcribed in overlapping domains in imaginal discs, suggesting that DWnt4 may cooperate with wg during limb patterning.
Wnt基因编码在进化上保守的分泌蛋白，这些蛋白在发育过程中发挥关键作用。尽管Wnt蛋白具有高度保守的特征，但它们也表现出序列差异，这几乎肯定导致了它们信号传导活性的多样性。我们之前报道过，DWnt4和无翅（wg）这两个不同的成簇Wnt基因，在果蝇胚胎发育过程中可能具有拮抗作用或不同的功能。在这里，我们提供证据表明，这两个基因在成虫发育过程中都能引发相似的细胞反应。沿着成虫盘的前后（A/P）边界异位表达DWnt4会改变成虫附肢的形态发生。在翅盘中，DWnt4通过诱导背板向翅的转变模拟异位Wg活性，表明这两种分子具有相似的信号传导能力。为此，我们证明DWnt4可以挽救触角和平衡棒中wg功能缺失的表型，并且能够在翅场特化中替代Wg。我们还表明，这两个基因在成虫盘中的重叠区域转录，这表明DWnt4可能在肢体模式形成过程中与wg协同作用。
