MUTATIONS IN A STEROID HORMONE-REGULATED GENE DISRUPT THE METAMORPHOSIS OF THE CENTRAL-NERVOUS-SYSTEM IN DROSOPHILA
MUTATIONS IN A STEROID HORMONE-REGULATED GENE DISRUPT THE METAMORPHOSIS OF THE CENTRAL-NERVOUS-SYSTEM IN DROSOPHILA
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DOI：
10.1016/0012-1606(91)90328-z
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发表时间：
1991-11-01
影响因子：
2.7
通讯作者：
WHITE, K
中科院分区：
文献类型：
--
作者：
RESTIFO, LL;WHITE, K
类固醇激素对脊椎动物和无脊椎动物神经系统的作用包括改变神经元结构、调节神经元分化和程序性细胞死亡。特别是，昆虫的中枢神经系统（CNS）变态需要暴露于类固醇蜕皮激素20-羟基蜕皮酮（ecdysterone）的精确模式。为了测试类固醇激素对昆虫神经系统的影响是否由于基因表达模式的改变，我们检查了卵巢外激素调节位点broad复合物（BR-C）的果蝇突变体。本报告记录了依赖于br - c功能的中枢神经系统重组的各个方面。在野生型变态过程中，中枢神经系统各组分之间以及与体壁之间发生剧烈的形态发生运动。这些运动，特别是食管下神经节与胸神经节的分离，发育中的视觉系统的定位，以及左右脑半球的融合，在br -突变体中都是紊乱的。此外，一组突变体在视叶神经节内和视叶神经节之间显示出视叶神经节的紊乱。在brand1(1)2个补体群的突变体中发现视叶紊乱，但在补体群中没有。这表明这个复杂位点的三个互补群代表了正常中枢神经系统重组所必需的不同但重叠的功能。本研究表明，蜕皮激素调节的基因表达对中枢神经系统变态至关重要，说明果蝇作为研究类固醇激素作用于神经系统的遗传基础的模型系统的效用。
The actions of steroid hormones on vertebrate and invertebrate nervous systems include alterations in neuronal architecture, regulation of neuronal differentiation, and programmed cell death. In particular, central nervous system (CNS) metamorphosis in insects requires a precise pattern of exposure to the steroid molting hormone 20-hydroxyecdysone (ecdysterone). To test whether the effects of steroid hormones on the insect nervous system are due to changes in patterns of gene expression, we examinedDrosophilamutants of the ecdysterone-regulated locus, theBroad Complex (BR-C). This report documents aspects of CNS reorganization which are dependent onBR-Cfunction. During wild-type metamorphosis, CNS components undergo dramatic morphogenetic movements relative to each other and to the body wall. These movements, in particular, the separation of the subesophageal ganglion from the thoracic ganglion, the positioning of the developing visual system, and the fusion of right and left brain hemispheres, are deranged inBR-Cmutants. In addition, a subset of mutants shows disorganization of optic lobe neuropil, both within and among optic lobe ganglia. Optic lobe disorganization is found in mutants of thebrandl(1)2Bccomplementation groups, but not in those of therbpcomplementation group. This suggests that the three complementation groups of this complex locus represent distinct but overlapping functions necessary for normal CNS reorganization. This study demonstrates that ecdysterone-regulated gene expression is essential for CNS metamorphosis, illustrating the utility ofDrosophilaas a model system for investigating the genetic basis of steroid hormone action on the nervous system.