title: Phenotypic flexibility of thermogenesis in the hwamei (Garrulax canorus): responses to cold acclimation.
abstract: Cold acclimation in birds involves a comprehensive array of physiological and morphological adjustment ranging from changes in aerobic enzyme activity to metabolic rate and organ mass. In the present study, we investigated phenotypic variation in thermogenic activity in the hwamei (Garrulax canorus) under normal (35°C) or cold (15°C) ambient temperature conditions. Acclimation to an ambient temperature of 15°C for 4 wk significantly increased the body mass, basal metabolic rate (BMR), and energy intake, including both gross energy intake and digestible energy intake, compared with birds kept at 35°C. Furthermore, birds acclimated to 15°C increased the dry mass of their liver and kidneys, but not their heart and pectoral muscles, and displayed higher state-4 respiration in the liver, kidneys, heart, and pectoral muscles, and higher cytochrome-c oxidase (COX) activity in liver, kidney, and pectoral muscle, compared with those kept at 35°C. There was a positive correlation between BMR and state-4 respiration in all of the above organs except the liver, and between BMR and COX activity in all of the above organs. Taken together, these data illustrate the morphological, physiological, and enzymatic changes associated with cold acclimation, and support the notion that the hwamei is a bird species from temperate climates that exhibits high phenotypic flexibility of thermogenic capacity.
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and.
authors.forename: Li-Meng
authors.initials: LM
authors.lastname: Zhou
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and.
authors.forename: Su-Su
authors.initials: SS
authors.lastname: Xia
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and.
authors.forename: Run-Mei
authors.initials: RM
authors.lastname: Wang
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou, China.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Zheng
authors.affiliation: School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China; and Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou, China ljs@wzu.edu.cn.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Liu
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D001481:Basal Metabolism / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003080:Cold Temperature; D004063:Digestion / Q000502:physiology; D003576:Electron Transport Complex IV / Q000378:metabolism; D002149:Energy Intake; D009929:Organ Size / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D046109:Passeriformes / Q000502:physiology*; D010641:Phenotype; D022722:Thermogenesis / Q000502:physiology*
chemical_list: D003576:Electron Transport Complex IV
keywords: basal metabolic rate; cold acclimation; cytochrome-c oxidase; digestive efficiency; state-4 respiration