Role of the proneural gene, atonal, in formation of Drosophila chordotonal organs and photoreceptors.
Role of the proneural gene, atonal, in formation of Drosophila chordotonal organs and photoreceptors.
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发表时间：
1995-07
期刊：
影响因子：
4.6
通讯作者：
A. Jarman;Yan Sun;L. Jan;Y. Jan
中科院分区：
文献类型：
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作者：
A. Jarman;Yan Sun;L. Jan;Y. Jan
果蝇基因无序编码一种基本的螺旋-环-螺旋蛋白，类似于无毛-鳞状复合体(AS-C)的原神经基因编码的那些蛋白。在果蝇三叉神经节中，AS-C是选择外部感觉器官神经前体所必需的。我们已经分离出无性系突变体，这表明该基因编码神经原基因，与脊索器官和光感受器有关。在无调性突变体中，所有可观察到的成体脉络膜器官和几乎所有胚胎脉络膜器官都无法形成；所有成体感光细胞都缺失。对于这两种类型的感觉器官，这种缺陷在前体形成的水平上已经很明显了。因此，它是表皮-神经决定过程中的一个失败，即神经损伤。由于细胞凋亡和缺乏分裂刺激，光感受器的形成失败导致无调性突变的成像盘的萎缩。缺乏光感受器也应该消除由分化光感受器而产生的信号，这是野生型眼盘中形态发生沟运动所必需的。然而，在无核突变盘中仍可观察到残留的形态发生沟。这可能反映了皱纹的启动过程，而不是依赖于发育中的光感受器发出的信号。
The Drosophila gene atonal encodes a basic helix-loop-helix protein similar to those encoded by the proneural genes of the achaete-scute complex (AS-C). The AS-C are required in the Drosophila PNS for the selection of neural precursors of external sense organs. We have isolated mutants of atonal, which reveal that this gene encodes the proneural gene for chordotonal organs and photoreceptors. In atonal mutants, all observable adult chordotonal organs, and almost all embryonic chordotonal organs fail to form; all adult photoreceptors are missing. For both types of sense organ, this defect is already apparent at the level of precursor formation. Therefore it is a failure in the epidermal-neural decision process i.e. a proneural defect. The failure to form photoreceptors results in atrophy of the atonal mutant imaginal disc, due to apoptosis and lack of stimulation of division. Lack of photoreceptors should also eliminate signalling that arises from differentiating photoreceptors and is required for morphogenetic furrow movement in the wild-type eye disc. Nevertheless, a remnant morphogenetic furrow is still observed in the atonal mutant disc. This presumably reflects the process of furrow initiation, which would not depend on signals from developing photoreceptors.