title: Fat deposition pattern and mechanism in response to dietary lipid levels in grass carp, Ctenopharyngodon idellus.
abstract: This study aimed to evaluate the fat deposition pattern and lipid metabolic strategies of grass carp in response to dietary lipid levels. Five isonitrogenous diets (260 g kg-1crude protein) containing five dietary lipid levels (0, 20, 40, 60, 80 g kg-1) were fed to quadruplicate groups of 15 fish with initial weight 200 g, for 8 weeks. The best growth performance and feed utilization was observed in fish fed with lipid level at 40 g kg-1. MFI and adipose tissue lipid content increased with increasing dietary lipid level up to 40 g kg-1, and higher lipid level in diet made no sense. Fish adapted to high lipid intake through integrated regulating mechanisms in several related tissues to maintain lipid homeostasis. In the present study, grass carp firstly increased PPARγ and CPT1 expressions in adipose tissue to elevate adipocyte differentiation and lipolysis to adapt to high lipid intake above 40 g kg-1. In liver, fish elevated hepatic lipid uptake but depressed biosynthesis of hepatic FAs, resulted in no difference in HSI and liver lipid content among the groups. Only in muscle, fish showed a significant fat deposition when the lipid intake above 40 g kg-1. The excess lipid, derived from enhanced serum TC and TG contents, was more likely to induce deposition in muscle rather than lipid uptake by adipose tissue in grass carp fed with high dietary lipid, indicating the muscle of grass carp might be the main responding organ to high lipid intake.
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Yuan
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China. xufang_liang@hotmail.com.
authors.forename: Xu-Fang
authors.initials: XF
authors.lastname: Liang
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Liwei
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Jinguang
authors.initials: J
authors.lastname: Fang
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Aixuan
authors.initials: A
authors.lastname: Li
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Cai
authors.affiliation: National Aquafeed Safety Assessment Station, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Min
authors.initials: M
authors.lastname: Xue
authors.affiliation: National Aquafeed Safety Assessment Station, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Fisheries of Huazhong Agricultural University, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, Hubei, China.
authors.forename: Qingchao
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002347:Carps / Q000254:growth & development / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D004435:Eating; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D009132:Muscles / Q000378:metabolism
chemical_list: D004041:Dietary Fats
keywords: Fat deposition; Gene expression; Growth performance; Lipid metabolism; Protein sparing