A better understanding of carotenoid dynamics (transport, absorption, metabolism, and deposition) is essential to develop a better strategy to improve astaxanthin (Ax) retention in muscle of Atlantic salmon. To achieve that, a comparison of post-smolt salmon with (+ Ax) or without (− Ax) dietary Ax supplementation was established based on a transcriptomic approach targeting pyloric, hepatic, and muscular tissues. Results in post-smolts showed that the pyloric caeca transcriptome is more sensitive to dietary Ax supplementation compared to the other tissues. Key genes sensitive to Ax supplementation could be identified, such as cd36 in pylorus, agr2 in liver, or fbp1 in muscle. The most modulated genes in pylorus were related to absorption but also metabolism of Ax. Additionally, genes linked to upstream regulation of the ferroptosis pathway were significantly modulated in liver, evoking the involvement of Ax as an antioxidant in this process. Finally, the muscle seemed to be less impacted by dietary Ax supplementation, except for genes related to actin remodelling and glucose homeostasis. In conclusion, the transcriptome data generated from this study showed that Ax dynamics in Atlantic salmon is characterized by a high metabolism during absorption at pyloric caeca level. In liver, a link with a potential of ferroptosis process appears likely via cellular lipid peroxidation. Our data provide insights into a better understanding of molecular mechanisms involved in dietary Ax supplementation, as well as its beneficial effects in preventing oxidative stress and related inflammation in muscle.

更好地了解类胡萝卜素动力学（运输、吸收、代谢和沉积）对于制定更好的策略来改善大西洋鲑鱼肌肉中虾青素 (Ax) 的保留至关重要。为了实现这一目标，基于针对幽门、肝脏和肌肉组织的转录组学方法，对添加 (+ Ax) 或不添加 (- Ax) 膳食 Ax 的鲑鱼进行了比较。后幼崽的结果表明，与其他组织相比，幽门盲肠转录组对膳食 Ax 补充剂更敏感。关键基因斧补充敏感，能够识别诸如CD36在幽门，AGR2在肝脏或FBP1在肌肉中。幽门中最受调节的基因与 Ax 的吸收和代谢有关。此外，与铁死亡途径上游调控相关的基因在肝脏中受到显着调节，这表明 Ax 作为抗氧化剂参与了这一过程。最后，除了与肌动蛋白重塑和葡萄糖稳态相关的基因外，肌肉似乎受膳食 Ax 补充剂的影响较小。总之，这项研究产生的转录组数据表明，大西洋鲑鱼的 Axe 动力学特征在于在幽门盲囊水平吸收期间的高代谢。在肝脏中，可能通过细胞脂质过氧化作用与铁死亡过程的潜在联系。我们的数据为更好地理解膳食 Ax 补充剂所涉及的分子机制提供了见解，