title: Enhanced muscle nutrient content and flesh quality, resulting from tryptophan, is associated with anti-oxidative damage referred to the Nrf2 and TOR signalling factors in young grass carp (Ctenopharyngodon idella): Avoid tryptophan deficiency or excess.
abstract: Flesh quality, muscle antioxidant status and related signalling molecule expressions were investigated in young grass carp fed six levels of tryptophan (Trp) for 8 weeks. The results indicated that fish fed 0.7 (deficiency) and 6.1g Trp g/kg (excess) diets exhibited lower muscle water-holding capacity, tenderness, cathepsin activity, protein levels, lipids and collagen contents. Optimal Trp reversed these negative effects, which were related to enhanced glutathione (GSH) content and glutathione peroxidase (GPx) activities regulated at gene transcription levels, rather than to superoxide dismutase (SOD) or catalase (CAT). The expression of signalling molecules [Kelch-like ECH-associated protein 1, target of rapamycin (TOR) and ribosomal S6 protein kinase 1] involved in the NF-E2-related factor 2 (Nrf2) pathway revealed a potential method of Trp-enhanced antioxidant defence. Collectively, the present study indicated that appropriate Trp levels improved flesh quality partly related to the enhancement of antioxidant ability through Nrf2 and TOR signalling.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; The Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Wei-Dan
authors.initials: WD
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Hai-Lang
authors.initials: HL
authors.lastname: Wen
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; The Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; The Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Sheng-Yao
authors.initials: SY
authors.lastname: Kuang
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Tang
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Wu-Neng
authors.initials: WN
authors.lastname: Tang
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Zhang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; The Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Sichuan, Chengdu 611130, China. Electronic address: zhouxq@sicau.edu.cn.
authors.forename: Xiao-Qiu
authors.initials: XQ
authors.lastname: Zhou
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Sichuan, Chengdu 611130, China; The Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Sichuan, Chengdu 611130, China. Electronic address: fenglin@sicau.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
mesh_terms: D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002347:Carps / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000502:physiology*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000502:physiology*; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D014364:Tryptophan; D058570:TOR Serine-Threonine Kinases
keywords: Antioxidant defence; Flesh quality; Gene expression; Grass carp; NF-E2-related factor 2; Tryptophan