Strigini M, Cohen S M
European Molecular Biology Laboratory, Heidelberg, Germany.
Development. 1997 Nov;124(22):4697-705. doi: 10.1242/dev.124.22.4697.
The secreted protein Hedgehog (Hh) transmits a signal from posterior to anterior cells that is essential for limb development in insects and vertebrates. In Drosophila, Hh has been thought to act primarily to induce localized expression of Decapentaplegic and Wingless which in turn relay patterning cues at long range. We report here that Hh plays an additional role in patterning the wing. By replacing endogenous Hh activity with that of a membrane-tethered form of Hh, we show that Hh acts directly to pattern the central region of the wing, in addition to its role as an inducer of Dpp. Comparing the biological activities of secreted and membrane-tethered Hh provides evidence that Hh forms a local concentration gradient and functions as a concentration-dependent morphogen in the fly wing.
分泌蛋白刺猬索尼克（Hh）从前部细胞向后部细胞传递信号，这对于昆虫和脊椎动物的肢体发育至关重要。在果蝇中，人们一直认为Hh主要作用是诱导截瘫蛋白（Decapentaplegic）和无翅蛋白（Wingless）的局部表达，进而在远距离传递模式形成信号。我们在此报告，Hh在翅膀模式形成中还发挥着额外作用。通过用膜结合形式的Hh替代内源性Hh活性，我们发现Hh除了作为Dpp的诱导剂外，还直接作用于翅膀中央区域的模式形成。比较分泌型和膜结合型Hh的生物学活性，为Hh在果蝇翅膀中形成局部浓度梯度并作为浓度依赖性形态发生素发挥作用提供了证据。
