水解鱼蛋白是典型的多肽蛋白，具有吸收速度快、不易饱和等优点，可有效提供机体蛋白合成所需氨基酸。肌肉生长抑制素（mstn）作为肌肉生成负调控因子，是肌肉蛋白质代谢的一个关键位点。水解鱼蛋白是否通过mstn影响肌肉蛋白合成，进而影响鱼类肌肉生成，目前并不清楚。本项目拟以大菱鲆为研究对象，通过水解鱼蛋白（多肽）与鱼粉（完整蛋白）的比较研究及与mstn基因表达的相关性分析，阐明水解鱼蛋白对肌肉mstn的作用规律；利用mstn抑制剂，探究mstn在水解鱼蛋白调控肌肉蛋白质代谢通路akt/tor（合成）和akt/foxo（分解）中的介导作用；通过养殖实验，结合水解鱼蛋白对肌肉营养组成及质构特性、肌纤维形态结构和肌肉生成相关因子的影响，系统评价水解鱼蛋白对肌肉生成的调控作用。从而揭示水解鱼蛋白通过mstn对大菱鲆肌肉生成的作用机理，以期为营养素途径调控肌肉生成进而改善肌肉品质提供理论基础。

Fish protein hydrolysate is a typical peptide protein, which has many advantages, such as fast absorption, carriers being not easy to saturate etc. It can effectively provide amino acids for muscle protein synthesis. Myostatin (mstn), as a negative regulator of muscle formation, is a key site for muscle protein synthesis and degradation. However, it is not clear whether fish protein hydrolysate affects muscle protein synthesis through mstn, and thus affects fish muscle formation. This project will intend to use turbot (Scophthalmus maximus) as a research object. The effect of fish protein hydrolysate on muscle mstn will be clarified by using the comparative study of fish protein hydrolysate (peptide) and fishmeal (intact protein) as well as the correlation analysis between the level of dietary fish protein hydrolysate and mstn gene expression. On this basis, mstn inhibitors were injected in vivo to explore the mediating role of mstn in the regulation of fish protein hydrolysate on akt/tor (protein synthesis) and akt/foxo (protein degradation) of the muscle protein metabolic pathway. The regulation of fish protein hydrolysate on muscle production is systematically evaluated by long-term feeding experiments, which combined with the effects of fish protein hydrolysate on muscle nutrient composition and texture characteristics, muscle fiber morphology and muscle formation related factors. Results of this project will reveal the mechanisms involved in the regulation of muscle formation by fish protein hydrolysate, and be helpful for the exploring nutritional measures for promoting skeletal muscle formation and improving muscle quality.