糖类较为廉价，且具有节约蛋白质的作用。但受生理条件限制，鱼类对糖类的利用率相对较低。研究表明，鱼类糖代谢障碍可能是由糖异生作用调控的缺失或受损所致，但潜在机制尚不明确。项目组前期通过转录组分析，确定RNA结合蛋白QKI和SIRT1与鱼体糖异生作用密切相关，但二者间的相互作用及QKI介导的转录后调控在鱼体糖异生调节中的作用尚不清楚。本项目以体外培养团头鲂肝细胞为研究对象，利用RNA干扰及质粒转染技术，明确QKI在鱼体糖异生调节中的作用；在细胞水平上干扰SIRT1活性，进而探讨其介导的去乙酰化修饰对QKI转录活性的调控作用，并利用RNA免疫沉淀技术确定QKI靶分子；在此基础上，添加不同浓度葡萄糖，诱导肝细胞糖异生强度发生变化。通过QKI介导的基因转录后调控的变化，初步阐明其对鱼体糖异生作用的调控机理，以期部分揭示鱼类糖代谢障碍的分子机制，并为高糖饲料的研发和应用提供参考。

Carbohydrates are the cheapest energy source for fish, and have the protein-sparing potential. However, unlike the case of mammals, fish appears to have a limited capability to use dietary carbohydrate for energy purposes. Previous studies suggested that this might be ascribed to the impaired postprandial down-regulation of gluconeogenesis. However, the potential mechanisms are still poorly understood. Through transcriptome analysis, we obtained two functional genes, namely the RNA-binding protein QKI (Quaking) and SIRT1 (silent information regulation 2 homolog 1), which are closely involved in the gluconeogenesis pathway in fish. However, the activation processes of QKI mediated by SIRT1 are barely understood, as also holds true for their roles in the regulation of gluconeogenesis. Bearing this in mind, using Megalobrama amblycephala as the target animal, the present study aims to 1) ascertain the functions of QKI in the regulation of gluconeogenesis in hepatocytes in vitro through RNA interference; 2) illustrate the activation mechanisms of QKI through the deacetylation process mediated by SIRT1; 3) identify the target molecules of QKI through RNA-immunoprecipitation (RIP); 4) induce an altered gluconeogenesis of hepatocytes through glucose manipulations, and investigate the post-transcription regulation of QKI in gluconeogenesis. The results obtained here will partly illustrate the potential mechanisms by which QKI regulates the gluconeogenesis pathway in fish. It will also facilitate our understanding of the carbohydrate utilization by fish, as would benefit the development and application of high-carbohydrate feed in the aquaculture industry.