长链多不饱和脂肪酸（LC-PUFA）对人体健康具有重要功能。鱼类是LC-PUFA的主要来源。但养殖过程中，广泛使用的植物性脂肪源显著降低了鱼体肌肉LC-PUFA水平，特别是DHA水平。为提高养殖鱼体LC-PUFA水平，研究者们从研发转基因油料作物和提高鱼体LC-PUFA合成能力方面做了大量工作，并取得一定的效果。然而，LC-PUFA如何沉积于鱼体肌肉组织？其调控机制如何？目前尚未得到阐明。本项目聚焦调控肌肉DHA沉积的关键基因—长链脂酰辅酶Ａ合成酶6（acsl6），通过克隆鲤acsl6基因全长及候选启动子，检测其转录因子，分析饲料DHA水平与肌肉Acsl6表达量和DHA水平之间的关系，探讨植物脂肪源影响肌肉acsl6表达的调控机制，以阐明鲤acsl6功能及转录调控机制。项目成果为全面剖析鱼类肌肉LC-PUFA沉积机制奠定理论基础，并为实现鱼类精确营养调控，改善鱼肉品质提供新的视角。

Long chain polyunsaturated fatty acids (LC-PUFA) are beneficial to human health. Fish is the main source of LC-PUFA in the human diet. In aquaculture, plant lipid sources are widely used in formula feed, which seriously affects the LC-PUFA level (especial the DHA level) in farmed fish. In order to improve the LC-PUFA level in farmed fish, researchers have had some success in developing transgenic oil crops and improving the LC-PUFA biosynthetic capability of fish. However, the deposition process of LC-PUFA in fish muscle and its regulatory mechanism are still unclear. In this project, we focus on the long-chain fatty acyl coenzyme A synthetase 6 (acsl6), which is the key gene for mediating DHA deposition in muscle. Our research will first clone the full length of acsl6 cDNA and its candidate promoter sequence in common carp, and then confirm its transcription factors. Secondly, we will investigate the relationship between dietary DHA levels and the expression of acsl6 and DHA levels in fish muscle. Finally, we will further explore the regulatory mechanism of how plant lipids affect the expression of acsl6 in muscle. The objective of the present project is to elucidate the function of Acsl6 and its transcriptional regulatory mechanism in common carp. The present project will lay a theoretical foundation for comprehensively illuminating the deposition mechanism of LC-PUFA in fish muscle, as well as provide a new perspective for achieving accurate nutrition regulation and improving muscle quality in fish.