title: Temperature modulates hepatic carbohydrate metabolic enzyme activity and gene expression in juvenile GIFT tilapia (Oreochromis niloticus) fed a carbohydrate-enriched diet.
abstract: The effects of rearing temperature on hepatic glucokinase (GK), glucose-6-phosphatase (G6Pase) and Glucose-6-phosphate dehydrogenase (G6PD) activity and gene expression were studied in GIFT (genetically improved farmed tilapia) tilapia fed a high carbohydrate diet containing 28% crude protein, 5% crude lipid and 40% wheat starch. Triplicate groups of fish (11.28 g initial body weight) were fed the diet for 45 days at 22 °C, 28 °C or 34 °C. At the end of the trial, final body weight of juvenile at 28 °C (59.12 g) was higher than that of the fish reared at 22 °C (27.13 g) and 34 °C (43.17 g). Feed intake, feed efficiency and protein efficiency ratio were also better at 28 °C. Liver glycogen levels were higher at 28 °C, while plasma glucose levels were higher in the 22 °C group. Significant (P<0.05) effects of water temperature on enzymes activities and gene expression were observed. Hepatic GK activity and mRNA level were higher at 28 °C than at 34 °C. Higher G6Pase and G6PD activity and gene expression were observed at 22 °C. Overall, the data show that juveniles reared at 28 °C exhibited enhanced liver glycolytic capacity. In contrast, hepatic gluconeogenesis and lipogenesis were increased by low temperature (22 °C).
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: J
authors.initials: J
authors.lastname: Qiang
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: J
authors.initials: J
authors.lastname: He
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.affiliation: Fisheries College, Guangdong Ocean University, Zhanjiang 524025, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: M D
authors.initials: MD
authors.lastname: Kpundeh
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China. Electronic address: Xup@ffrc.cn.
authors.forename: P
authors.initials: P
authors.lastname: Xu
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: Z X
authors.initials: ZX
authors.lastname: Zhu
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004032:Diet; D004040:Dietary Carbohydrates / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005941:Glucokinase / Q000235:genetics / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000235:genetics / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017210:Tilapia / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
chemical_list: D004040:Dietary Carbohydrates; D029941:Fish Proteins; D012333:RNA, Messenger; D006003:Glycogen; D005954:Glucosephosphate Dehydrogenase; D005941:Glucokinase; D005952:Glucose-6-Phosphatase
keywords: Carbohydrate; Enzyme activity; Gene expression; Oreochromis niloticus; Temperature