Capdevila J, Guerrero I
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Spain.
EMBO J. 1994 Oct 3;13(19):4459-68. doi: 10.1002/j.1460-2075.1994.tb06768.x.
In the wing imaginal disc, the decapentaplegic (dpp) gene is expressed in a stripe of anterior cells near the anterior-posterior compartment boundary, and it is required solely in these cells for the entire disc to develop. In some viable segment polarity mutants, alterations in dpp expression have been demonstrated that correlate with changes in wing morphology. To test the hypothesis that the abnormal patterns of dpp expression are responsible directly for the mutant phenotypes, we have expressed dpp in ectopic places in wing imaginal discs, and we have found that dpp is able to cause overgrowth and pattern duplications in both anterior and posterior compartments of the wing disc. The alterations of the anterior compartment are strikingly similar to those observed in some viable segment polarity mutants. Thus, ectopic dpp alone can account for the phenotype of these mutants. We also show that ectopic expression of the segment polarity gene hedgehog (hh) gives similar morphological changes and activates dpp expression in the anterior compartment. This strongly suggests that the organizating activity of hh is mediated by dpp. We propose that the expression of dpp near the anterior-posterior compartment boundary is directed by the interaction between patched and hh, and that dpp itself could act as a general organizer of the patterning in the wing imaginal disc.
在翅成虫盘（wing imaginal disc）中，“五体不全”（decapentaplegic，dpp）基因在前-后隔室边界附近的一条前侧细胞带中表达，并且整个翅成虫盘的发育仅需要这些细胞中存在该基因。在一些存活的体节极性突变体中，已证实dpp表达的改变与翅形态的变化相关。为了检验dpp表达异常模式直接导致突变体表型这一假说，我们在翅成虫盘的异位位置表达了dpp，并且发现dpp能够在翅成虫盘的前侧和后侧隔室中导致过度生长和模式重复。前侧隔室的改变与在一些存活的体节极性突变体中观察到的改变惊人地相似。因此，单独的异位dpp就能解释这些突变体的表型。我们还表明，体节极性基因“刺猬”（hedgehog，hh）的异位表达会产生类似的形态变化，并在前侧隔室中激活dpp表达。这有力地表明，hh的组织活性是由dpp介导的。我们提出，前-后隔室边界附近dpp的表达是由“patched”与hh之间的相互作用所引导的，并且dpp自身可能作为翅成虫盘模式形成的一种通用组织者。
