Hong C C, Hashimoto C
Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Cell. 1995 Sep 8;82(5):785-94. doi: 10.1016/0092-8674(95)90475-1.
Dorsoventral polarity of the Drosophila embryo is induced by a ventral extracellular signal, which is produced by a locally activated protease cascade within the extraembryonic perivitelline compartment. Local activation of the protease cascade depends on a positional cue that is laid down during oogenesis outside the oocyte. Here we present evidence that the nudel gene encodes an essential component of this cue. The nudel gene, which is expressed in follicle cells covering the oocyte, encodes an unusual mosaic protein resembling an extracellular matrix protein with a central serine protease domain. Our findings suggest that embryonic dorsoventral polarity is defined by a positional cue that requires the nudel protein to anchor and to trigger the protease cascade producing the polarity-inducing signal.
果蝇胚胎的背腹极性是由一种腹侧细胞外信号诱导产生的，该信号由胚外卵黄周间隙内局部激活的蛋白酶级联反应产生。蛋白酶级联反应的局部激活取决于卵子发生过程中在卵母细胞外建立的位置线索。在这里，我们提供证据表明nudel基因编码这种线索的一个重要组成部分。nudel基因在覆盖卵母细胞的卵泡细胞中表达，编码一种不寻常的镶嵌蛋白，类似于具有中央丝氨酸蛋白酶结构域的细胞外基质蛋白。我们的研究结果表明，胚胎背腹极性是由一种位置线索定义的，该线索需要nudel蛋白来锚定并触发产生极性诱导信号的蛋白酶级联反应。
