Lan Q, Wu Z, Riddiford L M
Department of Zoology, University of Washington, Seattle 98195-1800, USA.
Insect Mol Biol. 1997 Feb;6(1):3-10. doi: 10.1046/j.1365-2583.1997.00151.x.
The responsiveness of several nuclear transcription factor genes to 20-hydroxyecdysone (20E) was characterized in an embryonic cell line, GV1, from Manduca sexta. The mRNA for the Manduca ecdysone receptor (MsEcR) was present in the GV1 cells and transiently increased 2.3-fold by 5 h after the addition of 2 micrograms/ml (4 x 10(-6) M) 20-hydroxyecdysone (20E). In contrast, Manduca ultraspiracle (MsUSP) mRNA level in the GV1 cells decreased slowly to half of its initial level by 12 h when exposed to the same concentration of 20E. The mRNAs for two putative transcription factors, MsE75 and MHR3, were induced in the GV1 cells by 20E, with that for E75 appearing within 1 h whereas that for MHR3 within 2 h. The ED50S for induction of MsE75 and MHR3 gene expression in GV1 cells were 1.2 x 10(-6) and 2.5 x 10(-6) M 20E, respectively.
在烟草天蛾的胚胎细胞系GV1中，对几种核转录因子基因对20-羟基蜕皮激素（20E）的反应性进行了表征。烟草天蛾蜕皮激素受体（MsEcR）的mRNA存在于GV1细胞中，在添加2微克/毫升（4×10⁻⁶ M）的20-羟基蜕皮激素（20E）后5小时，其瞬时增加了2.3倍。相比之下，当暴露于相同浓度的20E时，GV1细胞中烟草天蛾超气门蛋白（MsUSP）的mRNA水平在12小时内缓慢下降至初始水平的一半。两种假定的转录因子MsE75和MHR3的mRNA在GV1细胞中被20E诱导，E75的mRNA在1小时内出现，而MHR3的mRNA在2小时内出现。在GV1细胞中诱导MsE75和MHR3基因表达的半数有效剂量（ED50）分别为1.2×10⁻⁶ M和2.5×10⁻⁶ M的20E。
