Department of Plants and Crops, Ghent University, 9000 Ghent, Belgium.
Institute of Evolutionary Biology (IBE), CSIC- Pompeu Fabra University, E-08003 Barcelona, Spain.
J Insect Physiol. 2019 Aug-Sep;117:103902. doi: 10.1016/j.jinsphys.2019.103902. Epub 2019 Jun 21.
The adult body size is species-specific and controlled by complex interactions between hormones and the IIS/TOR pathway. To analyze the role of target of rapamycin (TOR) in the growth and development of the insect, expression levels of TOR were silenced in the model and pest insect red flour beetle, Tribolium castaneum. Injection of dsRNA into the last larval instar decreased pupal mass and size, while the amount of food intake by the larvae was not affected. These results place TcTOR downstream of nutrition as a transducer for nutritional signals to increase larval growth. In addition, TcTOR-silencing notably decreased the size of the adult appendages. Analysis of the wings and elytra revealed a decrease in cell size and number of these appendages in the TcTOR-silenced insects. This reduction in size was correlated with a decrease of transcriptional levels of marker genes controlling the cell cycle. Altogether, these results suggest a pivotal role for TcTOR in integrating nutritional signals and regulation of body and appendages growth.
成人体型是物种特异性的，由激素和 IIS/TOR 途径之间的复杂相互作用控制。为了分析雷帕霉素靶蛋白（TOR）在昆虫生长和发育中的作用，我们在模式和害虫赤拟谷盗中沉默了 TOR 的表达水平。将 dsRNA 注射到最后一个幼虫龄期会降低蛹的质量和大小，而幼虫的食物摄入量不受影响。这些结果表明 TcTOR 位于营养物质的下游，作为营养信号的传感器，以增加幼虫的生长。此外，沉默 TcTOR 显著降低了成虫附肢的大小。对翅膀和鞘翅的分析表明，沉默 TcTOR 的昆虫的这些附肢的细胞大小和数量减少。这种尺寸的减小与控制细胞周期的标记基因转录水平的降低相关。总之，这些结果表明 TcTOR 在整合营养信号和调节身体和附肢生长方面起着关键作用。
