Berger E M, Morganelli C M
In Vitro. 1984 Dec;20(12):959-74. doi: 10.1007/BF02619669.
When Drosophila cell lines are exposed to physiological doses of the steroid molting hormone, ecdysterone, they enter mitotic arrest and differentiate morphologically. These responses are accompanied by specific changes in gene expression. Several enzyme activities (acetylcholinesterase, beta-galactosidase, dopa decarboxylase, and catalase) are induced and the synthesis of a cytoplasmic actin and the four small heat-shock proteins is initiated. Several of these ecdysterone inducible genes have been physically isolated and characterized, in several cases by DNA sequencing. Current studies focus on introducing cloned ecdysterone inducible genes into responsive cells by DNA mediated transfection. Once it is clear that these introduced genes acquire the normal pattern of hormone-regulated gene expression in the cell, in vitro mutagenesis can be used before transfection to modify their structure. Transient expression, then, can become a functional assay to define regions of DNA flanking the coding region of inducible genes that are needed for proper gene expression and regulation in cultured cells.
当果蝇细胞系暴露于生理剂量的类固醇蜕皮激素——蜕皮甾酮时，它们会进入有丝分裂停滞并发生形态分化。这些反应伴随着基因表达的特定变化。几种酶活性（乙酰胆碱酯酶、β-半乳糖苷酶、多巴脱羧酶和过氧化氢酶）被诱导，并且启动了细胞质肌动蛋白和四种小热休克蛋白的合成。其中一些蜕皮甾酮诱导基因已被物理分离并进行了表征，在某些情况下还进行了DNA测序。目前的研究重点是通过DNA介导的转染将克隆的蜕皮甾酮诱导基因导入反应性细胞。一旦明确这些导入的基因在细胞中获得了激素调节基因表达的正常模式，就可以在转染前使用体外诱变来修饰它们的结构。然后，瞬时表达可以成为一种功能测定，以确定诱导基因编码区侧翼的DNA区域，这些区域是培养细胞中正常基因表达和调控所必需的。
