(2S)-3-(2-sulfanylidene-1,3-dihydroimidazol-4-yl)-2-(trimethylazaniumyl)propanoate (ergothioneine, ET) is hydrophilic antioxidant produced only by certain low-level organisms, but has been reported in the organs of some animals upon dietary intake, facilitated by the ergothioneine transporter (ETT). In this study, it was hypothesised that ETT is involved in the uptake of ET from diet in salmonids. The mechanism of ET uptake was evaluated through knockdown of candidate gene encoding ETT in a cell line (RTG-2) from rainbow trout (Oncorhynchus mykiss). ETT gene expression in blood cells and certain tissues from rainbow trout was also investigated as ET from the diet is expected to be carried over to the muscle. Knockdown of an ETT candidate (E1) in RTG-2 cells resulted in a remarkable decrease in E1 mRNA expression; uptake of ET was lower in the knocked group than in the control group suggesting that E1 functions as an ETT for rainbow trout. Furthermore, the expression of ETT gene in different tissues including the muscle points to ET uptake from the diet to the muscle of salmonids. In conclusion, this study partly reveals the possible pathway underlying ET uptake from the diet and its deposition in the muscle of edible fish species.

(2 S )-3-(2-sulfanylidene-1,3-dihydroimidazol-4-yl)-2-(trimethylazaniumyl)propanoate (ergothioneine, ET) 是亲水性抗氧化剂，仅由某些低水平生物产生，但已有报道在某些动物的器官中通过饮食摄入，由麦角硫因转运蛋白 (ETT) 促进。在这项研究中，假设 ETT 参与了鲑鱼从饮食中摄取 ET。通过敲低虹鳟（Oncorhynchus mykiss）细胞系（RTG-2）中编码ETT的候选基因来评估ET摄取的机制）。还研究了虹鳟鱼的血细胞和某些组织中的 ETT 基因表达，因为饮食中的 ET 预计会转移到肌肉中。在 RTG-2 细胞中敲除 ETT 候选物 (E1) 导致 E1 mRNA 表达显着降低；敲除组对 ET 的吸收低于对照组，表明 E1 对虹鳟鱼起到 ETT 的作用。此外，ETT 基因在包括肌肉在内的不同组织中的表达表明鲑鱼从饮食中摄取 ET 到肌肉。总之，这项研究部分揭示了从饮食中摄取 ET 及其在可食用鱼类肌肉中沉积的可能途径。