申请人近些年主要围绕TOR信号通路系统地开展了必需氨基酸促生长、蛋白合成和免疫调控等分子机制的研究，这在团头鲂研究中尚为首次，为我国这一重要的淡水养殖品种产业化可持续发展提供了助力，也为鱼类氨基酸营养研究进行了有益补充。申请人系统地开展了精氨酸、亮氨酸、色氨酸等对团头鲂糖、脂代谢的调控机制，这在水产动物营养研究领域有所突破。水产动物对于糖类的代谢和利用能力差，以前研究往往关注于饲料糖水平带来的影响，而申请人则从氨基酸调控的角度，为提高水产动物糖代谢和利用提供了新的思路。

(1)亮氨酸营养生理研究

团头鲂亮氨酸需求量为1.44%-1.61%。适宜的饲料亮氨酸水平可以促进团头鲂幼鱼的生长，激活TOR信号通路并提高其核心基因的表达，从而加强氨基酸的利用及促进蛋白合成。1.72%饲料亮氨酸水平可以激活TOR信号通路，进而影响胰岛素引号通路核心基因的表达(IRS-1、Akt、PI3K)，提高血清胰岛素水平，提高糖代谢能力。然而，高亮氨酸水平(2.94%)导致了高血糖现象，这可能是由于高亮氨酸水平过度激活了TOR信号通路的核心因子S6K1的表达，从而负反馈抑制胰岛素信号通路，进而抑制糖酵解，促进糖异生。此外，1.33%饲料亮氨酸水平可以增强脂肪生成，通过调控脂肪合成途径关键基因(SREBP1、FAS、ACC)提高血清甘油三酯含量。

(2)精氨酸营养生理研究

团头鲂幼鱼精氨酸需要量为1.84%-2.46%。适宜的饲料精氨酸水平能促进团头鲂的生长并可以激活TOR信号通路、提高其核心基因表达，从而加强氨基酸的利用率、促进蛋白合成。同时发现，适宜的精氨酸水平也可以激活胰岛素信号通路，进一步影响糖酵解、糖异生从而促进糖代谢，并且影响磷酸戊糖途径从而增加脂肪合成。然而过量的精氨酸水平会导致S6K1过表达，从而导致胰岛素抵抗，影响团头鲂对饲料糖、脂的正常代谢，而引发高血糖。因此，适宜的精氨酸补充可以促进鱼类生长，提高氨基酸利用率，提高蛋白合成，促进糖代谢，而过量补充会降低生长，并导致胰岛素抵抗。

(3)色氨酸调控糖代谢研究

团头鲂幼鱼色氨酸需要量为0.20%。适宜的饲料色氨酸水平能促进团头鲂的生长并可以提高蛋白质效率和全鱼体蛋白合成。色氨酸缺乏则激活IGF-1和GK的表达，促进肝脏的糖酵解过程。同样，过量的色氨酸水平会导致G6Pase和PEPCK过表达，促进肝脏的糖异生过程，同时下调IGF-1和GK的表达，抑制糖酵解过程。因此，适宜的色氨酸补充可以促进鱼类生长，提高蛋白合成，而色氨酸缺乏则降低生长，促进糖酵解过程，过量补充色氨酸则促进糖异生过程。

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